2.20: Cupboard
|
Cupboard
Norwegian-American Aslak Olsen Lie, c.1860 Wood (pine), glass, metal Gift of Ella Mavis MHAHS 1984.011.0001 |
Diamonds were a hallmark of the furniture-maker Aslak Olsen Lie (pronounced LEE), appearing across the many styles of his work. Lie was born in Norway and spent the first thirty years of his career there. When he emigrated, he brought with him the skills and thinking of a mature craftsman. Lie’s family was one of the first Norwegian families to settle in the Blue Mounds region. He quickly adapted to making both American and Norwegian styles of furniture. The Norwegian cut-out ends on this stepback cupboard show how Lie would also mix those styles. The result was furniture that is distinctly Norwegian-American.
Compare the unusual interior decoration of this cupboard with that of the traveling box in the previous area of this exhibit.
For a complete essay on this object, click here.
In an advertisement he took out in a Blue Mounds area newspaper, Norwegian immigrant Aslak Olsen Lie (pronounced LEE) promoted his cabinetmaking business on his ability to make furniture according to American and European fashions. But while the advertisement seems to suggest that Lie alternated between working in one style or the other, the reality is more complicated. Examination of Lie’s post-emigration furniture shows that he regularly mixed forms and stylistic elements from his native Norway with those popular in the United States. The stepback cupboard that he made around 1860 for the Skindrud family is one example of such blending. Considering this piece within the greater context of his life and career sheds light on Lie’s own formation of immigrant identity.
Aslak Olsen Lie’s career as a cabinetmaker spanned over six decades and straddled the Atlantic Ocean. Lie was born in the Valdres district of south-central Norway in 1798. As a young man in Norway, Lie learned the techniques involved in making furniture and developed an aesthetic sense for Norwegian design. As a cabinetmaker in rural Norway, he developed his own variations within the decorative traditions of that culture. A fifty-year old man when he emigrated in 1848, Lie came to Wisconsin an already mature craftsman. His family was among the first from Norway to settle in the Blue Mounds area and was a central figure in establishing a stream of immigrants from Valdres to Blue Mounds. In Wisconsin, Lie had to both adapt to the tastes of his new, American, clientele, as well as continue to appeal to other Norwegian immigrants. Lie’s resultant work varied based upon the taste of each client, bearing more characteristic of one style or the other. However, the majority of Lie’s work in Wisconsin shows some degree of hybridization – the synthesizing of the two influences to create a distinctly Norwegian-American style of furniture.
The stepback cupboard made for the Skindrud family displays characteristics of Lie’s hybrid styles in his work in Wisconsin. Stepback cupboards are an American form that have a shallow upper casement that “steps back” to produce a shelf where the deeper base juts out. Cupboards of this form, particularly those with glass upper casement doors, often emphasize straight lines and angularity. In contrast to this American form, the cupboards Lie made while in Norway were dominated by the use of dramatic curving ornamentation. In the Skindrud cupboard, Lie flanked the shelf with scrollwork ends. In doing so, he incorporated Norwegian curvilinear design into the angular American form. Additionally, the red exterior and patterned blue paint inside the cupboard draw upon the Norwegian tradition of decorating furniture with bold colors.
Aslak Lie’s hybridization of furniture styles reveals an active formation of immigrant identity. Lie created new designs out of elements he knew from both Norway and America. He was still able to show creative self-expression through his cabinetry. When designing a piece of furniture, Lie knowingly selected what he wanted to take and incorporate from Norwegian and American decorative traditions. In form and style, Aslak Olsen Lie’s post-immigration works display a great variation as he interpreted his neighbors’ and his own ethnic identity. As a case study, Aslak Lie demonstrates how the process of acculturation and hybridization among first generation immigrants is an active process. Lie consciously shaped and used ethnic character to navigate his new market. By so doing, he pushed his own artistic boundaries, as well as both Norwegian and American furniture to new forms.
References
Bakken, Reidar. Snikkaren Aslak Olsen Lie: Bygdekunstnar i Valdres og Wisconsin 1798-1886, Craftsman on two Continents. Oslo: Novus forlag, 2000.
Holzhueter,John O. “Aslak Lie and the Challenge of the Artifact,” The Wisconsin Magazine of History, Vol. 70, No. 1 (Autumn, 1986): 3-20. http://content.wisconsinhistory.org/...n/wmh/id/36301


11.1: Raman- Application
If one can extract all of the vibrational information corresponds a molecule, its molecular structure can then be determined. In the field of spectroscopy, two main techniques are applied in order to detect molecular vibrational motions: Infrared spectroscopy (IR) and Raman spectroscopy. Raman Spectroscopy has its unique properties which have been used very commonly and widely in Inorganic, Organic, Biological systems [1] and Material Science [2], [3], etc for both qualitative and quantitative applications
Introduction
Generally speaking, vibrational and rotational motions are unique for every molecule. The uniqueness to molecules are in analogous to fingerprint identification of people hence the term molecular fingerprint. Study the nature of molecular vibration and rotation is particularly important in structure identification and molecular dynamics. Two of the most important techniques in studying vibration/rotation information are IR spectroscopy and Raman spectroscopy. IR is an absorption spectroscopy which measures the transmitted light. Coupling with other techniques, such as Fourier Transform, IR has been highly successful in both organic and inorganic chemistry.
Unlike IR, Raman spectroscopy measures the scattered light (Figure 2). There are three types of scattered lights: Rayleigh scattering, Stokes scattering, and anti-stokes scattering. Rayleigh scattering is elastic scattering where there is no energy exchange between the incident light and the molecule. Stokes scattering happens when there is an energy absorption from the incident light, while anti-stokes scattering happens when the molecule emits energy to the incident light. Thus, Stokes scattering results in a red shift, while anti-stokes scattering results in a blue shift. (Figure 1) Stokes and Anti-Stokes scattering are called Raman scattering which can provide the vibration/rotation information
The intensity of Rayleigh scattering is around 10 7 times that of Stokes scattering. [4] According to the Boltzmann distribution, anti-Stokes is weaker than Stokes scattering. Thus, the main difficulty of Raman spectroscopy is to detect the Raman scattering by filtering out the strong Rayleigh scattering. In order to reduce the intensity of the Rayleigh scattering, multiple monochromators are applied to selectively transmit the needed wave range. An alternative way is to use Rayleigh filters. There are many types of Rayleigh filters. One common way to filter the Rayleigh light is by interference.
Because of the weakness of Raman scattering, the resolving power of a Raman spectrometer is much higher than an IR spectrometer. A resolution of 10 5 is needed in Raman while 10 3 is sufficient in IR. [5] In order to achieve high resolving power, prisms, grating spectrometers or interferometers are applied in Raman instruments.
Numerous laser sources are available for both portable compact and bench top Raman instruments at wavelengths such as 266 nm, 355, nm, 441.6 nm, 514.5 nm, 532 nm, 632.8 nm, 785 nm and 1060 nm. Like other light scattering phenomena, Raman lines increases in intensity with the fourth power of the excitation frequency. For normal Raman spectroscopy, the excitation wavelength should be longer (less energy) that those absorbed for electronic transitions.
For quantitative work, spontaneous Raman scattering is directly proportional to the analyte concentration. And overall, the power of Raman lines can be expressed by:
\begin{equation} P=c P_{0} \nu_{\mathrm{s}}^{4} \alpha^{2} \end{equation}
where c is the concentration, P 0 is the laser power, \(\nu_{\mathrm{s}}\) is the laser frequency and \(\alpha\) is the scattering cross-section
Despite the limitations above, Raman spectroscopy has some advantages over IR spectroscopy as follows:
- Raman Spectroscopy can be used in aqueous solutions (while water can absorb the infrared light strongly and affect the IR spectrum).
- Because of the different selection rules, vibrations inactive in IR spectroscopy may be seen in Raman spectroscopy. This helps to complement IR spectroscopy.
- There is no destruction to the sample in Raman Spectroscopy. In IR spectroscopy, samples need to disperse in transparent matrix. For example grind the sample in solid KBr. In RS, no such destruction of the sample is needed.
- Glass vials can be used in RS (this should only work in the visible region. If in the UV region for excitation, glass is not applicable because it can strongly absorb UV light)
- Raman Spectroscopy needs relative short time. So we can do Raman Spectroscopy detection very quickly.
After analysis of the advantages and disadvantages of Raman Spectroscopy technique, we can begin to consider the application of Raman Spectroscopy in inorganic, organic, biological systems and Material Science, etc.
Applications
Raman Spectroscopy application in inorganic systems
X-ray diffraction (XRD) has been developed into a standard method of determining structure of solids in inorganic systems. Compared to XRD, it is usually necessary to obtain other information (NMR, electron diffraction, or UV-Visible) besides vibrational information from IR/Raman in order to elucidate the structure. Nevertheless, vibrational spectroscopy still plays an important role in inorganic systems. For example, some small reactive molecules only exist in gas phase and XRD can only be applied for solid state. Also, XRD cannot distinguish between the following bonds: –CN vs. –NC, –OCN vs. –NCO,–CNO vs. –ONC, -SCN vs. –NCS. [7] Furthermore, IR and Raman are fast and simple analytical method, and are commonly used for the first approximation analysis of an unknown compound.
Raman spectroscopy has considerable advantages over IR in inorganic systems due to two reasons. First, since the laser beam used in RS and the Raman-scattered light are both in the visible region, glass (Pyrex) tubes can be used in RS. On the other hand, glass absorbs infrared radiation and cannot be used in IR. However, some glass tubes, which contain rare earth salts, will gives rises to fluorescence or spikes. Thus, using of glass tubes in RS still need to be careful. Secondly, since water is a very weak Raman scatter but has a very broad signal in IR, aqueous solution can be directly analyzed using RS.
Raman Spectroscopy and IR have different selection rules. RS detects the polarizability change of a molecule, while IR detects the dipole momentum change of a molecule. Principle about the RS and IR can be found at Chemwiki Infrared Theory and Raman Theory . Thus, some vibration modes that are active in Raman may not be active IR, vice versa. As a result, both of Raman and IR spectrum are provided in the stucture study. As an example, in the study of Xenon Tetrafluoride. There are 3 strong bands in IR and solid Raman shows 2 strong bands and 2 weaker bands. These information indicates that Xenon Tetrafluoride is a planar molecule and has a symmetry of D4h. [8] Another example is the application of Raman Spectroscopy in homonuclear diatomic molecules. Homonuclear diatomic molecules are all IR inactive, fortunately, the vibration modes for all the homonuclear diatomic molecules are always Raman Spectroscopy active.
Raman Spectroscopy Application in Organic Systems
Unlike inorganic compounds, organic compounds have less elements mainly carbons, hydrogens and oxygens. And only a certain function groups are expected in organic specturm. Thus, Raman and IR spectroscopy are widely used in organic systems. Characteristic vibrations of many organic compounds both in Raman and IR are widely studied and summarized in many literature. [5] Qualitative analysis of organic compounds can be done base on the characteristic vibrations table.
| Vibration | Region(cm -1 ) | Raman intensity | IR intensity |
|---|---|---|---|
| v(O-H) | 3650~3000 | weak | strong |
| v(N-H) | 3500~3300 | medium | medium |
| v(C=O) | 1820~1680 | strong~weak | very strong |
| v(C=C) | 1900~1500 | very strong~medium | 0~weak |
“RS is similar to IR in that they have regions that are useful for functional group detection and fingerprint regions that permit the identification of specific compounds.”[1] While from the different selection rules of Raman Spectroscopy and IR, we can get the Mutual Exclusion rule [5], which says that for a molecule with a center of symmetry, no mode can be both IR and Raman Spectroscopy active. So, if we find a strong bond which is both IR and Raman Spectroscopy active, the molecule doesn't have a center of symmetry.
Pictured below are the IR and Raman spectra of chloroform, CHCl 3 , as an example of the complementarity of IR and Raman spectroscopy.
Non-classical Raman Spectroscopy
Although classical Raman Spectroscopy has been successfully applied in chemistry, this technique has some major limitations as follows[5]:
- The probability for photon to undergo Raman Scattering is much lower than that of Rayleigh scattering, which causes low sensitivity of Raman Spectroscopy technique. Thus, for low concentration samples, we have to choose other kinds of techniques.
- For some samples which are very easily to generate fluorescence, the fluorescence signal may totally obscure the Raman signal. We should consider the competition between the Raman Scattering and fluorescence.
- In some point groups, such as C 6 , D 6 , D 6h , C 4 h , D 2h , there are some vibrational modes that is neither Raman or IR active.
- The resolution of the classical Raman Spectroscopy is limited by the resolution of the monochromator.
In order to overcome the limitations, special techniques are used to modify the classical Raman Spectroscopy. These non-classical Raman Spectroscopy includes: Resonance Raman Spectroscopy, surface enhanced Raman Spectroscopy, and nonlinear coherent Raman techniques, such as hyper Raman spectroscopy
Resonance Raman Scattering (RRS)
The resonance effect is observed when the photon energy of the exciting laser beam is equal to the energy of the allowed electronic transition. Since only the allowed transition is affected, (in terms of group theory, these are the totally symmetric vibrational ones.), only a few Raman bands are enhanced (by a factor of 10 6 ). As a result, RRS can increase the resolution of the classical Raman Spectroscopy, which makes the detection of dilution solution possible (concentrations as low as 10 -3 M). RRS is extensively used for biological molecules because of its ability to selectively study the local environment. As an example, the Resonance Raman labels are used to study the biologically active sites on the bond ligand. RRS can also be used to study the electronic excited state. For example, the excitation profile which is the Raman intensity as a function of incident laser intensity can tell the interaction between the electronic states and the vibrational modes. Also, it can be used to measure the atomic displacement between the ground state and the excited state.
Surface Enhanced Raman Scattering (SERS)
At 1974, Fleischmann discovered that pyridine adsorbed onto silver electrodes showed enhanced Raman signals. This phenomenon is now called surface enhanced Raman Scattering (SERS). Although the mechanism of SERS is not yet fully understood, it is believed to result from an enhancement either of transition polarizability, α,or the electric field, E, by the interaction with the rough metallic support.
Unlike RRS, SERS enhances every band in the Raman spectrum and has a high sensitivity. Due to the high enhancement (by a factor of 10 10~11 ), the SERS results in a rich spectrum and is an ideal tool for trace analysis and in situ study of interfacial process. Also, it is a better tool to study highly diluted solutions. A concentration of 4x10 -12 M was reported by Kneipp using SERS. [5]
Nonlinear Raman Spectroscopy
In a nonlinear process, the output is not linearly proportional to its input. This happens when the perturbation become large enough that the response to the perturbation doesn’t follows the perturbation’s magnitude. Nonlinear Raman Spectroscopy includes: Hyper Raman spectroscopy, coherent anti-Stokes Raman Spectroscopy, coherent Stokes Raman spectroscopy, stimulated Raman gain and inverse Ramen spectroscopy. Nonlinear Raman spectroscopy is more sensitive than classical Raman spectroscopy and can effectively reduce/remove the influence of fluorescence. The following paragraph will focus on the most useful nonlinear Raman spectroscopy---coherent anti-Stokes Raman Spectroscopy (CARS):
References
- Principles of Instrumental Analysis, fifth edition. Skoog, Holler and Nieman.
- Infrared and Raman Spectra of Inorganic and Coordination Compounds, fifth edition. Kazuo Nakamoto.
- Symmetry and Spectroscopy an introduction to vibrational and electronic spectroscopy. Daniel C. Harris, etc.
- P. Bisson, G. Parodi, D. Rigos, J.E. Whitten, The Chemical Educator, 2006, Vol. 11, No. 2
- B. Schrader, Infrared and Raman Spectroscopy, VCH, 1995, ISBN:3-527-26446-9
- S.A. Borman, Analytical Chemistry, 1982, Vol. 54, No. 9, 1021A-1026A
- K. Nakamoto, Infrared Spectra of Inorganic and Coordination Compounds, 3 rd edition. Wiley Intrsc John Wiley & Sons, New York London Sydney Toronto, 1978
- H.H. Claassen, C.L. Chernick, J.G. Malm, 1963 J. Am. Chem. Soc., 85, 1927
Problems
- What are the advantages and disadvantages for Raman spectroscopy, comparing with IR spectroscopy?
- Please briefly explain the mutual exclusive principle in Raman and IR spectroscopy.


7.2: Choosing an Organizational Type
What you’ll learn to do: list and explain the important factors in choosing an organizational type
The organizational type you choose for your business, sometimes called a “legal structure,” can impact your taxes and income. In this section you’ll learn about the key factors that business owners should consider when choosing an organizational type.
Learning Objectives
- Explain the important factors in choosing an organizational type
Selecting a Form of Business Ownership
One of the first and most important decisions a business owner makes is selecting the organizational form under which he or she will operate. The following are some common organizational types (also called “legal structures”):
- Sole proprietorship
- General partnership
- Franchise
- Limited partnerships and limited liability partnerships (LLP)
- Limited liability company (LLC)
- C corporation
- S corporation
Each form of ownership has advantages, disadvantages, risks, and rewards that can affect the business’s chances for long-term success. The following are some of the important factors business owners should consider when selecting a form of ownership.
Cost of Start-up
Setting up a business can involve little more than printing some business cards, or it may entail hiring a corporate attorney to draft corporate charters, agreements, and articles of incorporation. As the forms of business ownership become more complex, the cost associated with establishing the business also increases. Every business owner must decide how long he/she wants to wait before getting the business up and running and also how much of his/her own money to invest.
Control vs. Responsibility
One of the primary reasons people give for wanting to start their own business is the desire to be independent and “be your own boss.” Different legal structures provide the owner with more or less control and authority. There are trade-offs in each case, though, because with autonomy and control come responsibility. For instance, if you’re the sole proprietor of a business with no employees, as a one-person show, you retain all the control, but you also have all the work and responsibility. Other forms of business (such as partnerships, for example,) may mean relinquishing some control, but, in return, the responsibility (and liability) may be spread among several principals. You’ll learn more about these trade-offs later in the module.
Profits—to Share or Not to Share
Many first-time business owners look to people like Bill Gates, Oprah Winfrey, or Ben & Jerry and aspire to their level of wealth and success. How a business’s profits are shared (or not shared) is determined by the legal structure. Some owners are willing to share the profits in exchange for assistance and support establishing and running the business. Other business owners make the conscious decision to limit the scope and nature of the business to avoid having to bring in others, thereby retaining all of the income themselves.
Taxation
When planning to start a new business, many people instinctively seek the advice of an attorney as the first step in the process. However, legal advice is not actually what’s needed initially. Instead, no matter how large or small your business is going to be, it’s much more important to first get the advice of a seasoned tax professional, such as a CPA. The reason for this is that each form of business ownership is treated differently by the IRS and by state and local taxing authorities. Depending on the legal structure of the business, the owner may be taxed at a lower rate than someone working for a large company, or the owner might see his or her business income taxed twice, sometimes with additional speciality taxes imposed by governmental agencies. The time for a business owner to decide how heavy a tax burden he/she is willing to bear is at the start of the business, not on April 15 when taxes are due.
Entrepreneurial Ability
At some point you’ve probably known someone with a particular knack for something (like fixing cars or baking bread) and said, “You should start your own business!” But if you are a talented cake decorator, say, does that necessarily mean you have the requisite knowledge, skills, and abilities to open and run a successful commercial or retail bakery? It’s often easier said than done. Many businesses fail despite the owner’s enthusiasm and/or talent, because the owner lacks the deep knowledge and expertise needed to transform an interest or hobby into a commercial enterprise. Performing an honest and accurate appraisal of one’s skills, background, and entrepreneurial abilities before launching a business can prevent disappointment and failure later on.
Risk Tolerance
Everyone’s tolerance for risk is different. Some people enjoy the rush of skydiving and rollercoasters, while others prefer to stick to the carousel or keep their feet on the ground. In business, one’s degree of risk tolerance should be compatible with the form of ownership being considered. For example, a forty-five-year old entrepreneur with dependents might seek to protect her accumulated assets (real estate, savings, retirement, etc.) and therefore select a legal structure that carries less personal financial risk. Every prospective business owner must gauge what he or she is willing to risk losing and choose a form of business accordingly.
Financing
Few business owners start a business with lottery winnings or many years’ worth of savings. Many seek funding from a bank, venture capitalist, private investor, or credit union in order to get their businesses off the ground. Lenders may be one of the greatest influences on the choice of business ownership—even more decisive than the owner’s preference or ambition. Since there is risk inherent in any business venture, especially start-ups, lenders often require the business to be structured in a way that best assures the repayment of funds (whether the business makes it or not). Even businesses that have been established for a long time may be forced to change their legal structure when seeking funding to expand their operations. If an owner anticipates needing funding at any point during the life of the business, selecting a form of ownership that aligns with lender requirements from the start may be a wise decision.
Continuity and Transferability
Finally, business owners need to consider if they want their business to outlive them (or carry on after they leave). If an owner is looking to start a business that can be passed on to his or her children or other family members, then the legal structure of the business is extremely important. Certain organizational types “die” with the owner, so it’s crucial for the owner to decide how and whether a business will persist and/or be sold to new ownership.
These are just some of the considerations business owners must weigh when selecting a form of business ownership. Many of these issues require owners to look far into the future of their business and imagine all of the “what if’s” associated with being self-employed. Although it is possible to change legal structure once the business is established, the more complex the business operations are the more complex the change will be. In some cases, the complexity of the situation can prevent the owner from making the change that’s desired. Considering as many of these factors as possible from the outset can save countless hours and great expense down the road.
In the coming sections we will explore the possible legal structures a business owner can choose and look at the advantages and disadvantages of each. We will begin with the simplest of all organizational types: the sole proprietorshi


22: Appendices Last updated Save as PDF Page ID 414760 OpenStax OpenStax Appendix A: The Periodic Table Appendix B: Essential Mathematics Appendix C: Units and Conversion Factors Appendix D: Fundamental Physical Constants Appendix E: Water Properties Appendix F: Composition of Commercial Acids and Bases Appendix G: Standard Thermodynamic Properties for Selected Substances Appendix H: Ionization Constants of Weak Acids Appendix I: Ionization Constants of Weak Bases Appendix J: Solubility Products Appendix K: Formation Constants for Complex Ions Appendix L: Standard Electrode (Half-Cell) Potentials Appendix M: Half-Lives for Several Radioactive Isotopes Answer Keys Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21


12.1: 12.1 Introduction to Conductance and Conductors
Unfortunately, the scientific theories explaining why certain materials conduct and others don’t are quite complex, rooted in quantum mechanical explanations in how electrons are arranged around the nuclei of atoms. Contrary to the well-known “planetary” model of electrons whirling around an atom’s nucleus as well-defined chunks of matter in circular or elliptical orbits, electrons in “orbit” don’t really act like pieces of matter at all. Rather, they exhibit the characteristics of both particle and wave, their behavior constrained by placement within distinct zones around the nucleus referred to as “shells” and “subshells.” Electrons can occupy these zones only in a limited range of energies depending on the particular zone and how occupied that zone is with other electrons. If electrons really did act like tiny planets held in orbit around the nucleus by electrostatic attraction, their actions described by the same laws describing the motions of real planets, there could be no real distinction between conductors and insulators, and chemical bonds between atoms would not exist in the way they do now. It is the discrete, “quantitized” nature of electron energy and placement described by quantum physics that gives these phenomena their regularity.
When an electron is free to assume higher energy states around an atom’s nucleus (due to its placement in a particular “shell”), it may be free to break away from the atom and comprise part of an electric current through the substance. If the quantum limitations imposed on an electron deny it this freedom, however, the electron is considered to be “bound” and cannot break away (at least not easily) to constitute a current. The former scenario is typical of conducting materials, while the latter is typical of insulating materials.
Some textbooks will tell you that an element’s conductivity or nonconductivity is exclusively determined by the number of electrons residing in the atoms’ outer “shell” (called the valence shell), but this is an oversimplification, as any examination of conductivity versus valence electrons in a table of elements will confirm. The true complexity of the situation is further revealed when the conductivity of molecules (collections of atoms bound to one another by electron activity) is considered.
A good example of this is the element carbon, which comprises materials of vastly differing conductivity: graphite and diamond. Graphite is a fair conductor of electricity, while diamond is practically an insulator (stranger yet, it is technically classified as a semiconductor , which in its pure form acts as an insulator, but can conduct under high temperatures and/or the influence of impurities). Both graphite and diamond are composed of the exact same types of atoms: carbon, with 6 protons, 6 neutrons and 6 electrons each. The fundamental difference between graphite and diamond being that graphite molecules are flat groupings of carbon atoms while diamond molecules are tetrahedral (pyramid-shaped) groupings of carbon atoms.
If atoms of carbon are joined to other types of atoms to form compounds, electrical conductivity becomes altered once again. Silicon carbide, a compound of the elements silicon and carbon, exhibits nonlinear behavior: its electrical resistance decreases with increases in applied voltage! Hydrocarbon compounds (such as the molecules found in oils) tend to be very good insulators. As you can see, a simple count of valence electrons in an atom is a poor indicator of a substance’s electrical conductivity.
All metallic elements are good conductors of electricity, due to the way the atoms bond with each other. The electrons of the atoms comprising a mass of metal are so uninhibited in their allowable energy states that they float freely between the different nuclei in the substance, readily motivated by any electric field. The electrons are so mobile, in fact, that they are sometimes described by scientists as an electron gas , or even an electron sea in which the atomic nuclei rest. This electron mobility accounts for some of the other common properties of metals: good heat conductivity, malleability and ductility (easily formed into different shapes), and a lustrous finish when pure.
Thankfully, the physics behind all this is mostly irrelevant to our purposes here. Suffice it to say that some materials are good conductors, some are poor conductors, and some are in between. For now it is good enough to simply understand that these distinctions are determined by the configuration of the electrons around the constituent atoms of the material.
An important step in getting electricity to do our bidding is to be able to construct paths for electrons to flow with controlled amounts of resistance. It is also vitally important that we be able to prevent electrons from flowing where we don’t want them to, by using insulating materials. However, not all conductors are the same, and neither are all insulators. We need to understand some of the characteristics of common conductors and insulators, and be able to apply these characteristics to specific applications.
Almost all conductors possess a certain, measurable resistance (special types of materials called superconductors possess absolutely no electrical resistance, but these are not ordinary materials, and they must be held in special conditions in order to be super conductive). Typically, we assume the resistance of the conductors in a circuit to be zero, and we expect that current passes through them without producing any appreciable voltage drop. In reality, however, there will almost always be a voltage drop along the (normal) conductive pathways of an electric circuit, whether we want a voltage drop to be there or not:
In order to calculate what these voltage drops will be in any particular circuit, we must be able to ascertain the resistance of ordinary wire, knowing the wire size and diameter. Some of the following sections of this chapter will address the details of doing this.
Review
- Electrical conductivity of a material is determined by the configuration of electrons in that materials atoms and molecules (groups of bonded atoms).
- All normal conductors possess resistance to some degree.
- Electrons flowing through a conductor with (any) resistance will produce some amount of voltage drop across the length of that conductor.


4.1: Solving Equations
Equations are a vital component to solve many mathematical questions. In fact most of all water related mathematical questions would require the use of one if not several equations. An equation is a mathematical statement that both sides of an “equal sign” are in fact equal.
Example \(\PageIndex{1}\)
\(3 + 1 = 4\) or \(5 - 3 = 4 - 2\)
Mathematical equations involve solving for an unknown or a variable. A variable is typically represented with a letter. That “letter” is what you are trying to solve.
Example \(\PageIndex{2}\)
\(3+X=4\)
What number must X be in order to make this equation correct?
Obviously, the answer is 1.
Now, this is a very simple example, but it will allow you to begin the process for solving more complex equations.
How did you solve the example above? Did you simply look at the equation and intuitively know that the answer was 1? Or did you use some mathematical process to solve for the variable? Let’s break it down.
Steps to solving equations;
- Get the unknown or unknowns on one side of the equation.
- Get the numbers on the other side of the equation.
-
Try and follow these helpful tips.
- If the problem is an addition problem, you will need to subtract
- If the problem is a subtraction problem, you will need to add
- If the problem is a multiplication problem, you will need to divide
- If the problem is a division problem, you will need to multiply
Depending on the type of problem, this will involve adding, subtracting, multiplying, or dividing. Perhaps several steps will need to be done to solve for the variable.
Since we will not be adding or subtracting in this course, we will focus on multiplication and division problems.
If the variable is next to a fraction or directly next to a number, solving for the variable will require either multiplying or dividing.
These next two examples are using multiplication and division to get the variable by itself. In order to prevent confusion, the variable of choice will be something other than an “X.”
Example \(\PageIndex{3}\)
| \(2N=10\) | What multiplied by 2 equals 10? In order to solve for “N” you will need to divide both sides of the equation by 2. |
| \(\dfrac{2N}{2}=10\) | By dividing the left side of the equation by 2, you isolate the variable. However, since you divided one side of the equation by a number you must do the same to the other side of the equation. |
| \(N=\dfrac{10}{2}\) | |
| \(N=5\) |
In this next example, a fraction of a variable will equal a number.
Example \(\PageIndex{4}\)
| \(\dfrac{2}{3} N=14\) | In order to isolate the variable in this type of problem, you will need to multiply and divided. First, divide both sides of the equation by 2 and then multiply both sides of the equation by 3. |
| \(\dfrac{2}{(2) 3} N=\dfrac{14}{2}\) | The two cancels out on the left side of the equation leaving N over 3 and 14 divided by 2 becomes 7. |
| \(\dfrac{N}{3}=7\) | Now, multiply both sides of the equation by 3. |
| \(\dfrac{(3) N}{3}=7 \times 3\) | Here, the 3 cancels out on the left and the right side of the equation becomes 21, which is the answer. |
| \(N=21\) |
How can you prove (or show) that 21 is the correct answer in the above example.
Exercise 4.1
- \(2 X=10\)
- \(3 N=15\)
- \(\dfrac{3}{4} G=9\)
- \(4 H+2=10\)
- \(\dfrac{1}{5} J+4=5\)
- \(13=\dfrac{3}{6} K-1\)
- \(3 B-5=2 B+8\)
- \(10 C-7=3 C+14\)
- \(\dfrac{4}{3} S-3=5\)
- \(14=2F+2\)
- \(7 X+2=9 X-10\)
- \(15=5+\dfrac{2}{5} P\)


20.7: Sage
Many computations, in seemingly very different areas of mathematics, can be translated into questions about linear combinations, or other areas of linear algebra. So Sage has extensive and thorough support for topics such as vector spaces.
Vector Spaces
The simplest way to create a vector space is to begin with a field and use an exponent to indicate the number of entries in the vectors of the space.
Elements can be built with the vector constructor.
Notice that vectors are printed with parentheses, which helps distinguish them from lists (though they alos look like tuples). Vectors print horizontally, but in Sage there is no such thing as a “row vector” or a “column vector,” though once matrices get involved we need to address this distinction. Finally, notice how the elements of the finite field have been converted to an alternate representation.
Once we have vector spaces full of vectors, we can perform computations with them. Ultimately, all the action in a vector space comes back to vector addition and scalar multiplication, which together create linear combinations.
Subspaces
Sage can create subspaces in a variety of ways, such as in the creation of row or column spaces of matrices. However, the most direct way is to begin with a set of vectors to use as a spanning set.
Notice that the information printed about
S
includes a “basis matrix.” The rows of this matrix are a basis for the vector space. We can get the basis, as a list of vectors (not rows of a matrix), with the
.basis()
method.
Notice that Sage has converted the spanning set of three vectors into a basis with two vectors. This is partially due to the fact that the original set of three vectors is linearly dependent, but a more substantial change has occurred.
This is a good place to discuss some of the mathematics behind what makes Sage work. A vector space over an infinite field, like the rationals or the reals, is an infinite set. No matter how expansive computer memory may seem, it is still finite. How does Sage fit an infinite set into our finite machines? The main idea is that a finite-dimensional vector space has a finite set of generators, which we know as a basis. So Sage really only needs the elements of a basis (two vectors in the previous example) to be able to work with the infinitely many possibilities for elements of the subspace.
Furthermore, for every basis associated with a vector space, Sage performs linear combinations to convert the given basis into another “standard” basis. This new basis has the property that as the rows of a matrix, the matrix is in reduced row-echelon form. You can see this in the basis matrix above. The reduced row-echelon form of a matrix is unique, so this standard basis allows Sage to recognize when two vector spaces are equal. Here is an example.
As you might expect, it is easy to determine the dimension of a vector space.
Linear Independence
There are a variety of ways in Sage to determine if a set of vectors is linearly independent or not, and to find relations of linear dependence if they exist. The technique we will show here is a simple test to see if a set of vectors is linearly independent or not. Simply use the vectors as a spanning set for a subspace, and check the dimension of the subspace. The dimension equals the number of vectors in the spanning set if and only if the spanning set is linearly independent.
So the first set of vectors,
[u, v, w]
, is linearly independent, while the second set,
[u, v, a^3*u + a^11*v]
, is not.
Abstract Vector Spaces
Sage does not implement many abstract vector spaces directly, such as \(P_n\text{,}\) the vector space of polynomials of degree \(n\) or less. This is due in part to the fact that a finite-dimensional vector space over a field \(F\) is isomorphic to the vector space \(F^n\text{.}\) So Sage captures all the functionality of finite-dimensional vector spaces, and it is left to the user to perform the conversions according to the isomorphism (which is often trivial with the choice of an obvious basis).
However, there are instances where rings behave naturally as vector spaces and we can exploit this extra structure. We will see much more of this in the chapters on fields and Galois theory. As an example, finite fields have a single generator, and the first few powers of the generator form a basis. Consider creating a vector space from the elements of a finite field of order \(7^6=117\,649\text{.}\) As elements of a field we know they can be added, so we will define this to be the addition in our vector space. For any element of the integers mod 7, we can multiply an element of the field by the integer, so we define this to be our scalar multiplication. Later, we will be certain that these two definitions lead to a vector space, but take that for granted now. So here are some operations in our new vector space.
You might recognize that this looks very familiar to how we add polynomials, and multiply polynomials by scalars. You would be correct. However, notice that in this vector space construction, we are totally ignoring the possibility of multiplying two field elements together. As a vector space with scalars from \({\mathbb Z}_7\text{,}\) a basis is the first six powers of the generator, \(\{1,\,a,\,a^2,\,a^3,\,a^4,\,a^5\}\text{.}\) (Notice how counting from zero is natural here.) You may have noticed how Sage consistently rewrites elements of fields as linear combinations — now you have a good explanation.
Here is what Sage knows about a finite field as a vector space. First, it knows that the finite field is a vector space, and what the field of scalars is. We suppress additional output with isomorphisms between the finite field structure and the vector space structure.
So the finite field (as a vector space) is isomorphic to the vector space \(({\mathbb Z}_7)^6\text{.}\) Notice this is not a ring or field isomorphism, as it does not fully address multiplication of elements, even though that is possible in the field.
Second, elements of the field can be converted to elements of the vector space easily.
Notice that Sage writes field elements with high powers of the generator first, while the basis in use is ordered with low powers first. The computations below illustrate the isomorphism preserving the structure between the finite field itself and its interpretation as a vector space, \(({\mathbb Z}_7)^6\text{.}\)
Linear Algebra
Sage has extensive support for linear algebra, well beyond what we have described here, or what we will need for the remaining chapters. Create vector spaces and vectors (with different fields of scalars), and then use tab-completion on these objects to explore the large sets of available commands.


Describe challenges associated with conducting research in lifespan development
Challenges Associated with Conducting Developmental Research
The previous sections describe research tools to assess development across the lifespan, as well as the ways that research designs can be used to track age-related changes and development over time. Before you begin conducting developmental research, however, you must also be aware that testing individuals of certain ages (such as infants and children) or making comparisons across ages (such as children compared to teens) comes with its own unique set of challenges. In the final section of this module, let’s look at some of the main issues that are encountered when conducting developmental research, namely ethical concerns, recruitment issues, and participant attrition.
Ethical Concerns
As a student of the social sciences, you may already know that
Institutional Review Boards (IRBs)
must review and approve all research projects that are conducted at universities, hospitals, and other institutions (each broad discipline or field, such as psychology or social work, often has its own code of ethics that must also be followed, regardless of institutional affiliation). An IRB is typically a panel of experts who read and evaluate proposals for research. IRB members want to ensure that the proposed research will be carried out ethically and that the potential benefits of the research outweigh the risks and potential harm (psychological as well as physical harm) for participants.
What you may not know though, is that the IRB considers some groups of participants to be more vulnerable or at-risk than others. Whereas university students are generally not viewed as vulnerable or at-risk, infants and young children commonly fall into this category. What makes infants and young children more vulnerable during research than young adults? One reason infants and young children are perceived as being at increased risk is due to their limited cognitive capabilities, which makes them unable to state their willingness to participate in research or tell researchers when they would like to drop out of a study. For these reasons, infants and young children require special accommodations as they participate in the research process. Similar issues and accommodations would apply to adults who are deemed to be of limited cognitive capabilities.
When thinking about special accommodations in developmental research, consider the
informed consent
process. If you have ever participated in scientific research, you may know through your own experience that adults commonly sign an informed consent statement (a contract stating that they agree to participate in research) after learning about a study. As part of this process, participants are informed of the procedures to be used in the research, along with any expected risks or benefits. Infants and young children cannot verbally indicate their willingness to participate, much less understand the balance of potential risks and benefits. As such, researchers are oftentimes required to obtain written informed consent from the parent or legal guardian of the child participant, an adult who is almost always present as the study is conducted. In fact, children are not asked to indicate whether they would like to be involved in a study at all (a process known as assent) until they are approximately seven years old. Because infants and young children cannot easily indicate if they would like to discontinue their participation in a study, researchers must be sensitive to changes in the state of the participant (determining whether a child is too tired or upset to continue) as well as to parent desires (in some cases, parents might want to discontinue their involvement in the research). As in adult studies, researchers must always strive to protect the rights and well-being of the minor participants and their parents when conducting developmental research.
watch it
This video from the US Department of Health and Human Services provides an overview of the Institutional Review Board process.
An additional challenge in developmental science is participant recruitment. Recruiting university students to participate in adult studies is typically easy. Many colleges and universities offer extra credit for participation in research and have locations such as bulletin boards and school newspapers where research can be advertised. Unfortunately, young children cannot be recruited by making announcements in Introduction to Psychology courses, by posting ads on campuses, or through online platforms such as Amazon Mechanical Turk. Given these limitations, how do researchers go about finding infants and young children to be in their studies?
The answer to this question varies along multiple dimensions. Researchers must consider the number of participants they need and the financial resources available to them, among other things. Location may also be an important consideration. Researchers who need large numbers of infants and children may attempt to recruit them by obtaining infant birth records from the state, county, or province in which they reside. Some areas make this information publicly available for free, whereas birth records must be purchased in other areas (and in some locations birth records may be entirely unavailable as a recruitment tool). If birth records are available, researchers can use the obtained information to call families by phone or mail them letters describing possible research opportunities. All is not lost if this recruitment strategy is unavailable, however. Researchers can choose to pay a recruitment agency to contact and recruit families for them. Although these methods tend to be quick and effective, they can also be quite expensive. More economical recruitment options include posting advertisements and fliers in locations frequented by families, such as mommy-and-me classes, local malls, and preschools or daycare centers. Researchers can also utilize online social media outlets like Facebook, which allows users to post recruitment advertisements for a small fee. Of course, each of these different recruitment techniques requires IRB approval. And if children are recruited and/or tested in school settings, permission would need to be obtained ahead of time from teachers, schools, and school districts (as well as informed consent from parents or guardians).
And what about the recruitment of adults? While it is easy to recruit young college students to participate in research, some would argue that it is too easy and that college students are samples of convenience. They are not randomly selected from the wider population, and they may not represent all young adults in our society (this was particularly true in the past with certain cohorts, as college students tended to be mainly white males of high socioeconomic status). In fact, in the early research on aging, this type of convenience sample was compared with another type of convenience sample—young college students tended to be compared with residents of nursing homes! Fortunately, it didn’t take long for researchers to realize that older adults in nursing homes are not representative of the older population; they tend to be the oldest and sickest (physically and/or psychologically). Those initial studies probably painted an overly negative view of aging, as young adults in college were being compared to older adults who were not healthy, had not been in school nor taken tests in many decades, and probably did not graduate high school, let alone college. As we can see, recruitment and random sampling can be significant issues in research with adults, as well as infants and children. For instance, how and where would you recruit middle-aged adults to participate in your research?
Attrition
Another important consideration when conducting research with infants and young children is
attrition
. Although attrition is quite common in longitudinal research in particular (see the previous section on longitudinal designs for an example of high attrition rates and selective attrition in lifespan developmental research), it is also problematic in developmental science more generally, as studies with infants and young children tend to have higher attrition rates than studies with adults. For example, high attrition rates in ERP (event-related potential, which is a technique to understand brain function) studies oftentimes result from the demands of the task: infants are required to sit still and have a tight, wet cap placed on their heads before watching still photographs on a computer screen in a dark, quiet room. In other cases, attrition may be due to motivation (or a lack thereof). Whereas adults may be motivated to participate in research in order to receive money or extra course credit, infants and young children are not as easily enticed. In addition, infants and young children are more likely to tire easily, become fussy, and lose interest in the study procedures than are adults. For these reasons, research studies should be designed to be as short as possible – it is likely better to break up a large study into multiple short sessions rather than cram all of the tasks into one long visit to the lab. Researchers should also allow time for breaks in their study protocols so that infants can rest or have snacks as needed. Happy, comfortable participants provide the best data.
Conclusions
Lifespan development is a fascinating field of study – but care must be taken to ensure that researchers use appropriate methods to examine human behavior, use the correct experimental design to answer their questions, and be aware of the special challenges that are part-and-parcel of developmental research. After reading this module, you should have a solid understanding of these various issues and be ready to think more critically about research questions that interest you. For example, what types of questions do you have about lifespan development? What types of research would you like to conduct? Many interesting questions remain to be examined by future generations of developmental scientists – maybe you will make one of the next big discoveries!
reduction in the number of research participants as some drop out over time
informed consent
a process of informing a research participant what to expect during a study, any risks involved, and the implications of the research, and then obtaining the person’s agreement to participate
Institutional Review Boards (IRBs)
a panel of experts who review research proposals for any research to be conducted in association with the institution (for example, a university)


16.4: Alkylation and Acylation of Aromatic Rings - The Friedel-Crafts Reaction
-
- Last updated
- Save as PDF
Objectives
After completing this section, you should be able to
- write the equation for the preparation of an alkylbenzene by a Friedel-Crafts alkylation reaction.
- identify the product formed from the Friedel-Crafts alkylation of a given aromatic compound.
- identify the aromatic compound needed to prepare a given arene by a Friedel-Crafts alkylation.
- identify the alkyl halide and catalyst needed to form a specified arene from a given aromatic compound.
- write the detailed mechanism for the Friedel-Crafts alkylation reaction, and identify the similarities between this reaction and those electrophilic aromatic substitution reactions you studied in Sections 16.1 and 16.2.
- show how alkyl halides and acylhalides can be used as alkylating agents in Friedel-Crafts alkylation reactions.
- discuss the limitations of the Friedel-Crafts alkylation reaction, paying particular attention to the structure of the alkyl halide, the structure of the aromatic substrate and the problem of polyalkylation.
- write an equation for a typical Friedel-Crafts acylation.
- write the detailed mechanism of the Friedel-Crafts acylation reaction.
- identify the product formed by the Friedel-Crafts acylation of a given aromatic compound.
- identify the aromatic compound, and the reagent and catalyst needed to prepare a given ketone through a Friedel-Crafts acylation reaction.
- Explain the following laws within the Ideal Gas Law
Key Terms
Make certain that you can define, and use in context, the key terms below.
- acyl group
- Friedel-Crafts acylation reaction
- Friedel-Crafts alkylation reaction
- polyalkylation
Study Notes
A Friedel-Crafts alkylation reaction is an electrophilic aromatic substitution reaction in which a carbocation is attacked by a pi bond from an aromatic ring with the net result that one of the aromatic protons is replaced by an alkyl group. If you prefer, you may regard these reactions as involving an attack by an aromatic ring on a carbocation. The latter approach is the one used in the textbook, but the former approach is probably more common.
When more than one alkyl group is introduced into an aromatic ring during the course of a Friedel-Crafts alkylation reaction, polyalkylation is said to have occurred.
The four limitations on the use of Friedel-Crafts alkylations are as follows:
- vinyl and aryl halides cannot be used to form carbocations.
- the aromatic substrate must not contain a strongly deactivating group, or groups, such as NH 2 , NHR or NR 2 , which form complexes with the Lewis acid catalyst and in so doing become strongly deactivating.
- polyalkylation, which can be overcome by using a large excess of the aromatic substrate.
- carbocation rearrangements may occur in any reaction that involves a carbocation.
The reaction of an aromatic substrate with an acid chloride (or acid anhydride) in the presence of an aluminum chloride catalyst is used to introduce an acyl group (C=O) into the aromatic ring through an electrophilic aromatic substitution mechanism. Such reactions are Friedel-Crafts acylation reactions.
Friedel-Crafts Alkylation
Friedel-Crafts Alkylation was first discovered by French scientist Charles Friedel and his partner, American scientist James Crafts, in 1877. This reaction allowed for the formation of alkyl benzenes from alkyl halides, but was plagued with unwanted supplemental activity that reduced its effectiveness.
The mechanism takes place as follows:
Step 1:
Step one creates a carbocation that acts as the electrophile in the reaction. This steps activates the haloalkane. Secondary and tertiary halides only form the free carbocation in this step.
Steps 2 and 3:
Step 2 has an electron pair from the aromatic ring attack the carbocation forming a new C-C bond. The arenium ion intermediate results with stabilization from multiple resonance forms. The loss of a proton then gives the neutral alkylated substitution product.
Final Products
The reactivity of haloalkanes increases as you move up the periodic table and increase polarity. This means that an RF haloalkane is most reactive followed by RCl then RBr and finally RI. This means that the Lewis acids used as catalysts in Friedel-Crafts Alkylation reactions tend have similar halogen combinations such as BF 3 , SbCl 5 , AlCl 3 , SbCl 5 , and AlBr 3 , all of which are commonly used in these reactions.
Some limitations of Friedel-Crafts Alkylation
There are possibilities of carbocation rearrangements when you are trying to add a carbon chain greater than two carbons. The rearrangements occur due to hydride shifts and methyl shifts. For example, the product of a Friedel-Crafts Alkylation will show an iso rearrangement when adding a three carbon chain as a substituent. One way to resolve these problems is through Friedel-Crafts Acylation.
Also, the reaction will only work if the ring you are adding a substituent to is not deactivated. Friedel-Crafts fails when used with compounds such as nitrobenzene and other strong deactivating systems.
Friedel-Crafts reactions cannot be preformed then the aromatic ring contains a NH 2 , NHR, or NR 2 substituent. The lone pair electrons on the amines react with the Lewis acid AlCl 3 . This places a positive charge next to the benzene ring, which is so strongly activating that the Friedel-Crafts reaction cannot occur.
Lastly, Friedel-Crafts alkylation can undergo polyalkylation. The reaction adds an electron donating alkyl group, which activates the benzene ring to further alkylation.
This problem does not occur during Friedel-Crafts Acylation because an acyl group is deactivating, thus prevents further acylations.
Friedel-Crafts Acylation
The goal of the reaction is the following:
The very first step involves the formation of the acylium ion which will later react with benzene:
The second step involves the attack of the acylium ion on benzene as a new electrophile to form one complex:
The third step involves the departure of the proton to reform aromaticity:
During the third step, AlCl 4 returns to remove a proton from the benzene ring, which enables the ring to return to aromaticity. In doing so, the original AlCl 3 is regenerated for use again, along with HCl. Most importantly, we have the first part of the final product of the reaction, which is a ketone. Thie first part of the product is the complex with aluminum chloride as shown:
The final step involves the addition of water to liberate the final product as the acylbenzene:
Because the acylium ion (as was shown in step one) is stabilized by resonance, no rearrangement occurs (unlike in Friedel-Crafts Alkylation reactions - see Limitation 1 above). Also, because of of the deactivation of the product, it is no longer susceptible to electrophilic attack and hence, no longer goes into further reactions (Limitation 3 above from Friedel-Crafts Alkylation reactions). However, as not all is perfect, Limitation 2 still prevails where Friedel-Crafts Acylation fails with strong deactivating rings.
Exercises
Exercise \(\PageIndex{1}\)
Which of the following will NOT undergo a rearrangement in a Friedel-Crafts reaction?
- Answer
-
A and E will not undergo a rearrangement.
Exercise \(\PageIndex{2}\)
Suggest an acyl chloride that was used to make the following compounds:
- Answer
-


11.3: Chapter Resources
-
- Last updated
- Save as PDF
Summary
Progress continues in the fight against hunger, yet an unacceptably large number of people still lack the food they need for an active and healthy life. About 795 million people in the world still go to bed hungry every night, and an even greater number live in poverty. Poverty is the major driver of food insecurity. Improvements in agricultural productivity are necessary to increase rural household incomes and access to available food but are insufficient to ensure food security. Food security is essentially built on four pillars: availability, access, utilization and stability. Women are crucial in the translation of the products of a vibrant agriculture sector into food and nutritional security for their households. They are often the farmers who cultivate food crops and produce commercial crops alongside the men in their households as a source of income. Over the past 20 years, a global obesity epidemic has emerged. Due to established health implications and rapid increase in prevalence, obesity is now a recognized major global health challenge, and no national success stories in curbing its growth have so far been reported. Genetic engineering is the name for methods that scientists use to introduce new traits or characteristics to an organism. Advocates say that application of genetic engineering in agriculture has resulted in benefits to farmers, producers, and consumers. Critics advise that the risks for the introduction of a GMO into each new ecosystem need to be examined on a case-by-case basis, alongside appropriate risk management measures.
Review Questions
-
Which one of the following is not one of the four pillars of food security?
- Availability
- Access
- Utilization
- Transformation
- Stability
-
Which one of the following statements is false regarding selective breeding?
- It results in genetic changes in the offspring
- It is anthropogenic
- Is reliant upon modern, lab-based methods
- It can produce new traits over time
- It was responsible for creating many common crops, such as maize (corn)
-
The US National Academy of Sciences, Engineering, and Medicine, along with other organizations such as the American Medical Association, have determined that GE crops…
- Are safe to consume
- Likely pose a risk to human health
- Pose a serious risk to human health
- Should be banned
- Have not been scientifically studied and therefore they cannot make any recommendations.
-
Which one of the following regions has obesity rates that are lower than rates of undernourishment?
- Middle East and North Africa
- Latin America and Caribbean
- Europe and Central Asia
- South Asia
-
Potatoes, tomatoes, and tobacco were are developed by humans many thousands of years ago by the genetic modification of wild nightshade species. Specifically, these crops were developed using…
- Selective breeding
- Horizontal gene transfer
- Epigenetics
- Natural selection
- Anthropogenesis
See Appendix for answers
Attributions
Bora, S., Ceccacci, I., Delgado, C. & Townsend, R . (2011) . Food security and confli ct. World Bank, Washington, DC. © World Bank. Retrieved from https://openknowledge.worldbank.org/...le/10986/11719 . Available under Creative Commons Attribution License 3.0 ( CC BY 3.0 ). Modified from original.
CK12. (2015). Food and nutrients . Accessed August 31, 2015 at http://www.ck12.org/user:a3F1aWNrQHdlYmIub3Jn/section/Food-and-Nutrients/ . Available under Creative Commons Attribution-NonCommercial 3.0 Unported License. ( CC BY-NC 3.0 ). Modified from original.
Godheja, J. (2013). Impact of GMO’S on environment and human health. Recent Research In Science And Technology, 5(5) . Retrieved from recent-science.com/index.php/rrst/article/view/17028. Available under Creative Commons Attribution License 3.0 ( CC BY 3.0 ). Modified from original.
Maghari, B. M., & Ardekani, A. M. (2011). Genetically Modified Foods and Social Concerns. Avicenna Journal of Medical Biotechnology , 3 (3), 109–117.
World Bank; Food and Agriculture Organization; International Fund for Agricultural Development . (2009) . Gender in agriculture sourcebook. Washington, DC: World Bank. © World Bank. Retrieved from https://openknowledge.worldbank.org/handle/10986/6603 . Available under Creative Commons Attribution License 3.0 ( CC BY 3.0 ). Modified from original.
World Bank Group . (2015) . Ending poverty and hunger by 2030: An agenda for the global food system. Washington, DC. © World Bank. Retrieved from https://openknowledge.worldbank.org/...le/10986/21771 . Available under Creative Commons Attribution License 3.0 IGO (CC BY 3.0 IGO). Modified from original.
Page attribution: Essentials of Environmental Science by Kamala Doršner is licensed under CC BY 4.0 . Modified from the original by Matthew R. Fisher. “Review Questions” is licensed under CC BY 4.0 by Matthew R. Fisher.


12.2: The Design and Evolution of the Presidency
-
- Last updated
- Save as PDF
Learning Objectives
By the end of this section, you will be able to:
- Explain the reason for the design of the executive branch and its plausible alternatives
- Analyze the way presidents have expanded presidential power and why
- Identify the limitations on a president's power
Since its invention at the Constitutional Convention of 1787, the presidential office has gradually become more powerful, giving its occupants a far-greater chance to exercise leadership at home and abroad. The role of the chief executive has changed over time, as various presidents have confronted challenges in domestic and foreign policy in times of war as well as peace, and as the power of the federal government has grown.
Inventing the Presidency
The Articles of Confederation made no provision for an executive branch, although they did use the term “president” to designate the presiding officer of the Confederation Congress, who also handled other administrative duties. 1 The presidency was proposed early in the Constitutional Convention in Philadelphia by Virginia’s Edmund Randolph, as part of James Madison’s proposal for a federal government, which became known as the Virginia Plan. Madison offered a rather sketchy outline of the executive branch, leaving open whether what he termed the “national executive” would be an individual or a set of people. He proposed that Congress select the executive, whose powers and authority, and even length of term of service, were left largely undefined. He also proposed a “council of revision” consisting of the national executive and members of the national judiciary, which would review laws passed by the legislature and have the power of veto. 2
Early deliberations produced agreement that the executive would be a single person, elected for a single term of seven years by the legislature, empowered to veto legislation, and subject to impeachment and removal by the legislature. New Jersey’s William Paterson offered an alternate model as part of his proposal, typically referred to as the small-state or New Jersey Plan. This plan called for merely amending the Articles of Confederation to allow for an executive branch made up of a committee elected by a unicameral Congress for a single term. Under this proposal, the executive committee would be particularly weak because it could be removed from power at any point if a majority of state governors so desired. Far more extreme was Alexander Hamilton’s suggestion that the executive power be entrusted to a single individual. This individual would be chosen by electors, would serve for life, and would exercise broad powers, including the ability to veto legislation, the power to negotiate treaties and grant pardons in all cases except treason, and the duty to serve as commander-in-chief of the armed forces (Figure 12.2).
Debate and discussion continued throughout the summer. Delegates eventually settled upon a single executive, but they remained at a loss for how to select that person. Pennsylvania’s James Wilson, who had triumphed on the issue of a single executive, at first proposed the direct election of the president. When delegates rejected that idea, he responded with the suggestion that electors, chosen throughout the nation, should select the executive. Over time, Wilson’s idea gained ground with delegates who were uneasy at the idea of an election by the legislature, which presented the opportunity for intrigue and corruption. The idea of a shorter term of service combined with eligibility for reelection also became more attractive to delegates. The framers of the Constitution struggled to find the proper balance between giving the president the power to perform the job on one hand and opening the way for a president to abuse power and act like a monarch on the other.
By early September, the Electoral College had emerged as the way to select a president for four years who was eligible for reelection. This process is discussed more fully in the chapter on elections. Today, the Electoral College consists of a body of 538 people called electors, each representing one of the fifty states or the District of Columbia, who formally cast votes for the election of the president and vice president (Figure 12.3). In forty-eight states and the District of Columbia, the candidate who wins the popular vote in November receives all the state’s electoral votes. In two states, Nebraska and Maine, the electoral votes are divided: The candidate who wins the popular vote in the state gets two electoral votes, but the winner of each congressional district also receives an electoral vote.
In the original design implemented for the first four presidential elections (1788–89, 1792, 1796, and 1800), the electors cast two ballots (but only one could go to a candidate from the elector’s state), and the person who received a majority won the election. The second-place finisher became vice president. Should no candidate receive a majority of the votes cast, the House of Representatives would select the president, with each state casting a single vote, while the Senate chose the vice president.
For the last two centuries or so, the Twelfth Amendment has worked fairly well. But this doesn’t mean the arrangement is foolproof. For example, the amendment created a separate ballot for the vice president but left the rules for electors largely intact. One of those rules states that the two votes the electors cast cannot both be for “an inhabitant of the same state with themselves.” 4 This rule means that an elector from, say, Louisiana, could not cast votes for a presidential candidate and a vice presidential candidate who were both from Louisiana; that elector could vote for only one of these people. The intent of the rule was to encourage electors from powerful states to look for a more diverse pool of candidates. But what would happen in a close election where the members of the winning ticket were both from the same state?
The nation almost found out in 2000. In the presidential election of that year, the Republican ticket won the election by a very narrow electoral margin. To win the presidency or vice presidency, a candidate must get 270 electoral votes (a majority). George W. Bush and Dick Cheney won by the skin of their teeth with just 271. Both, however, were living in Texas. This should have meant that Texas’s 32 electoral votes could have gone to only one or the other. Cheney anticipated this problem and had earlier registered to vote in Wyoming, where he was originally from and where he had served as a representative years earlier. 5 It’s hard to imagine that the 2000 presidential election could have been even more complicated than it was, but thanks to that seemingly innocuous rule in Article II of the Constitution, that was a real possibility.
Despite provisions for the election of a vice president (to serve in case of the president’s death, resignation, or removal through the impeachment process), and apart from the suggestion that the vice president should be responsible for presiding over the Senate, the framers left the vice president’s role undeveloped. As a result, the influence of the vice presidency has varied dramatically, depending on how much of a role the vice president is given by the president. Some vice presidents, such as Dan Quayle under President George H. W. Bush, serve a mostly ceremonial function, while others, like Dick Cheney under President George W. Bush, become a partner in governance and rival the White House chief of staff in terms of influence.
Link to Learning
Read about James Madison’s evolving views of the presidency and the Electoral College.
In addition to describing the process of election for the presidency and vice presidency, the delegates to the Constitutional Convention also outlined who was eligible for election and how Congress might remove the president. Article II of the Constitution lays out the agreed-upon requirements—the chief executive must be at least thirty-five years old and a “natural born” citizen of the United States (or a citizen at the time of the Constitution’s adoption) who has been an inhabitant of the United States for at least fourteen years. 6 While Article II also states that the term of office is four years and does not expressly limit the number of times a person might be elected president, after Franklin D. Roosevelt was elected four times (from 1932 to 1944), the Twenty-Second Amendment was proposed and ratified, limiting the presidency to two four-year terms.
An important means of ensuring that no president could become tyrannical was to build into the Constitution a clear process for removing the chief executive—impeachment. Impeachment is the act of charging a government official with serious wrongdoing; the Constitution calls this wrongdoing high crimes and misdemeanors. The method the framers designed required two steps and both chambers of the Congress. First, the House of Representatives could impeach the president by a simple majority vote. In the second step, the Senate could remove him or her from office by a two-thirds majority, with the chief justice of the Supreme Court presiding over the trial. Upon conviction and removal of the president, if that occurred, the vice president would become president.
Four presidents have faced impeachment proceedings in the House; none has been both impeached by the House and removed by the Senate. In the wake of the Civil War, President Andrew Johnson faced congressional contempt for decisions made during Reconstruction. President Richard Nixon faced an overwhelming likelihood of impeachment in the House for his cover-up of key information relating to the 1972 break-in at the Democratic Party’s campaign headquarters at the Watergate hotel and apartment complex. Nixon likely would have also been removed by the Senate, since there was strong bipartisan consensus for his impeachment and removal. Instead, he resigned before the House and Senate could exercise their constitutional prerogatives.
The 1990s brought the impeachment of President Bill Clinton, brought on by his lying about an extramarital affair with a White House intern named Monica Lewinsky. Voting fell largely along party lines. House Republicans felt the affair and Clinton’s initial public denial of it rose to a level of wrongdoing worthy of impeachment. House Democrats believed it fell short of an impeachable offense and that a simply censure made better sense. Clinton's trial in the Senate went nowhere because too few Senators wanted to move forward with removing the president.
The most recent impeachments were of President Donald Trump, who was impeached in the House twice. However, support for removal in the Senate did not meet the super-majority requirement, although on the second attempt in 2021 a solid majority favored removal. The first Trump impeachment brought charges of “abuse of power” and “obstruction of Congress” related to allegations that he improperly used his office to seek help from Ukrainian officials to facilitate his re-election. The second Trump impeachment was for “incitement of insurrection” related to the attack on the U.S. Capitol building during the counting of Electoral College votes on January 6, 2021. This second impeachment led to Republicans supporting impeachment in the House, including Representative Liz Cheney (R-WY), one of the central party leaders, and removal in the Senate, including Senator Mitt Romney (R-UT). 7 Ongoing federal investigations of the insurrection continue, and an attempt to launch an independent commission to investigate the event (similar to the 9/11 commission) passed the House, but was blocked by Republicans in the Senate. 8
Looking across the span of U.S. history, impeachment of a president remains a rare event indeed and removal has never occurred. However, with three of the five impeachment trials having occurred in the last twenty-five years, and with two of the five most recent presidents having faced impeachment, it will be interesting to watch if the trend continues in our partisan era. The fact that a president could be impeached and removed is an important reminder of the role of the executive in the broader system of shared powers. The same outcome occurred in the case of Andrew Johnson in the nineteenth century though he came closer to the threshold of votes needed for removal than did Clinton.
The Constitution that emerged from the deliberations in Philadelphia treated the powers of the presidency in concise fashion. The president was to be commander-in-chief of the armed forces of the United States, negotiate treaties with the advice and consent of the Senate, and receive representatives of foreign nations (Figure 12.4). Charged to “take care that the laws be faithfully executed,” the president was given broad power to pardon those convicted of federal offenses, except for officials removed through the impeachment process. 9 The chief executive would present to Congress information about the state of the union; call Congress into session when needed; veto legislation if necessary, although a two-thirds supermajority in both houses of Congress could override that veto; and make recommendations for legislation and policy as well as call on the heads of various departments to make reports and offer opinions.
Finally, the president’s job included nominating federal judges, including Supreme Court justices, as well as other federal officials, and making appointments to fill military and diplomatic posts. The number of judicial appointments and nominations of other federal officials is great. In recent decades, two-term presidents have nominated well over three hundred federal judges while in office. 10 Moreover, new presidents nominate close to five hundred top officials to their Executive Office of the President, key agencies (such as the Department of Justice), and regulatory commissions (such as the Federal Reserve Board), whose appointments require Senate majority approval. 11
The Evolving Executive Branch
No sooner had the presidency been established than the occupants of the office, starting with George Washington, began acting in ways that expanded both its formal and informal powers. For example, Washington established a cabinet or group of advisors to help him administer his duties, consisting of the most senior appointed officers of the executive branch. Today, the heads of the fifteen executive departments serve as the president’s advisers. 12 And, in 1793, when it became important for the United States to take a stand in the evolving European conflicts between France and other European powers, especially Great Britain, Washington issued a neutrality proclamation that extended his rights as diplomat-in-chief far more broadly than had at first been conceived.
Later presidents built on the foundation of these powers. Some waged undeclared wars, as John Adams did against the French in the Quasi-War (1798–1800). Others agreed to negotiate for significant territorial gains, as Thomas Jefferson did when he oversaw the purchase of Louisiana from France. Concerned that he might be violating the powers of the office, Jefferson rationalized that his not facing impeachment charges constituted Congress’s tacit approval of his actions. James Monroe used his annual message in 1823 to declare that the United States would consider it an intolerable act of aggression for European powers to intervene in the affairs of the nations of the Western Hemisphere. Later dubbed the Monroe Doctrine, this declaration of principles laid the foundation for the growth of American power in the twentieth century. Andrew Jackson employed the veto as a measure of policy to block legislative initiatives with which he did not agree and acted unilaterally when it came to depositing federal funds in several local banks around the country instead of in the Bank of the United States. This move changed the way vetoes would be used in the future. Jackson’s twelve vetoes were more than those of all prior presidents combined, and he issued them due to policy disagreements (their basis today) rather than as a legal tool to protect against encroachments by Congress on the president’s powers.
Over the course of the twentieth century, presidents expanded and elaborated upon these powers. The rather vague wording in Article II, which says that the “executive power shall be vested” in the president, has been subject to broad and sweeping interpretation in order to justify actions beyond those specifically enumerated in the document. 15 As the federal bureaucracy expanded, so too did the president’s power to grow agencies like the Secret Service and the Federal Bureau of Investigation. Presidents also further developed the concept of executive privilege, the right to withhold information from Congress, the judiciary, or the public. This right, not enumerated in the Constitution, was first asserted by George Washington to curtail inquiry into the actions of the executive branch. 16 The more general defense of its use by White House officials and attorneys ensures that the president can secure candid advice from his or her advisors and staff members.
Increasingly over time, presidents have made more use of their unilateral powers, including executive order s , rules that bypass Congress but still have the force of law if the courts do not overturn them. More recently, presidents have offered their own interpretation of legislation as they sign it via signing statements (discussed later in this chapter) directed to the bureaucratic entity charged with implementation. In the realm of foreign policy, Congress permitted the widespread use of executive agreement s to formalize international relations, so long as important matters still came through the Senate in the form of treaties. 17 Recent presidents have continued to rely upon an ever more expansive definition of war powers to act unilaterally at home and abroad. Finally, presidents, often with Congress's blessing through the formal delegation of authority, have taken the lead in framing budgets, negotiating budget compromises, and at times impounding funds in an effort to prevail in matters of policy.
Milestone
The Budget and Accounting Act of 1921
Developing a budget in the nineteenth century was a chaotic mess. Unlike the case today, in which the budgeting process is centrally controlled, Congresses in the nineteenth century developed a budget in a piecemeal process. Federal agencies independently submitted budget requests to Congress, and these requests were then considered through the congressional committee process. Because the government was relatively small in the first few decades of the republic, this approach was sufficient. However, as the size and complexity of the U.S. economy grew over the course of the nineteenth century, the traditional congressional budgeting process was unable to keep up. 18
Things finally came to a head following World War I, when federal spending and debt skyrocketed. Reformers proposed the solution of putting the executive branch in charge of developing a budget that could be scrutinized, amended, and approved by Congress. However, President Woodrow Wilson, owing to a provision tacked onto the bill regarding presidential appointments, vetoed the legislation that would have transformed the budgeting process in this way. His successor, Warren Harding, felt differently and signed the Budget and Accounting Act of 1921. The act gave the president first-mover advantage in the budget process via the first “executive budget.” It also created the first-ever budget staff at the disposal of a president, at the time called the Bureau of the Budget but decades later renamed the Office of Management and Budget (Figure 12.5). With this act, Congress willingly delegated significant authority to the executive and made the president the chief budget agenda setter.
The Budget Act of 1921 effectively shifted some congressional powers to the president. Why might Congress have felt it important to centralize the budgeting process in the executive branch? What advantages could the executive branch have over the legislative branch in this regard?
The growth of presidential power is also attributable to the growth of the United States and the power of the national government. As the nation has grown and developed, so has the office. Whereas most important decisions were once made at the state and local levels, the increasing complexity and size of the domestic economy have led people in the United States to look to the federal government more often for solutions. At the same time, the rising profile of the United States on the international stage has meant that the president is a far more important figure as leader of the nation, as diplomat-in-chief, and as commander-in-chief. Finally, with the rise of electronic mass media, a president who once depended on newspapers and official documents to distribute information beyond an immediate audience can now bring that message directly to the people via radio, television, and social media. Major events and crises, such as the Great Depression, two world wars, the Cold War, and the war on terrorism, have further contributed to presidential stature.


12.2: Trailblazer
Argumentative Research Trailblazer: Samin Nosrate
"I love doing the homework on recipes
and traditions . . . [I'm] excited to . . . read and research."
Figure \(12.2\) Fresh produce in markets like this one in France continue to inspire Samin Nosrat ( https://openstax.org/r/saminnosrat )’s recipes and ideas about food. (credit: “Légumes” by Arnaud 25/ Wikimedia Commons, Public Domain)
Food writer, chef, and TV host Samin Nosrat (b. 1979) was born in San Diego, California, to Iranian parents who, as followers of the Baha’i faith, immigrated to the United States to avoid religious persecution in their native country. When she was a student at the University of California, Berkeley, Nosrat became interested in cooking after a dinner at Berkeley’s well-known Chez Panisse, the restaurant belonging to award-winning chef, author, and food activist Alice Waters (b. 1944). Indeed, Nosrat became so interested that she got a job bussing tables at the restaurant several months later. After a year, she “moved up” to the kitchen, where she became a cook, working with Chez Panisse chef Cal Peternell.
Nosrat is well known for her cookbook Salt, Fat, Acid, Heat: Mastering the Elements of Good Cooking (2017), which won the prestigious James Beard Award in 2018 and also reached the New York Times best seller list that year. In the book, Nosrat claims that “like a scholar in search of primary sources,” she wanted “to experience authentic versions of the dishes” she loved. In addition to being a chef and writer, she has hosted an award-winning Netflix docuseries based on her book and until February 2021 was a regular columnist for The New York Times Magazine .
The underlying thesis of Nosrat’s Salt, Fat, Acid, Heat ( https://openstax.org/r/saltfatacid ) is that one should trust their senses in the kitchen, building confidence and developing the knowledge to gain this trust. Nosrat emphasizes an intuitive, elemental approach to cooking. “Anyone can cook anything and make it delicious,” Nosrat claims in the book’s introduction, establishing that excellent cooking is based on skill in using and balancing the four basic elements named in the title. She found solid evidence for this stance in Japan, where the cuisine features salt; in Italy, where the cuisine features fat; in Mexico, where the cuisine features acid; and in California, where the cuisine features heat. Nosrat explains these four elements in detail and supports her premise with research, interviews, and internships with talented cooks in different countries.
When talking about her television show, Nosrat says, “Good food around the world is more similar than it is different.” She considers how the chemistry and the culture of cooking work together around the world to create universally good food and, at the same time, create empathy and common ground. Nosrat’s audience can thus discern a persuasive purpose to her research into cooking. She argues that in addition to food, cooking is about people, and she hopes that by eating the food of a particular culture, readers and viewers will develop compassion for the people of that culture, despite politics or history. Seeking answers to important questions, Nosrat asks, “Does [food] really matter? Can food make a difference?”
As she continues her mission of research and writing, Nosrat feels the responsibility of her calling: to provide greater cross-cultural understanding and to center minoritized voices and traditions. She wants readers to feel safe inside her book, supported by the context she provides and her sensitivity to culture.
Discussion Questions
- Consider the rhetorical situation: In what ways does Samin Nosrat’s writing respond to purpose, audience, genre, stance, culture, and context?
- In what ways does Nosrat aim to make the cookbook genre persuasive or argumentative?
- What is Nosrat’s claim in Salt, Fat, Acid, Heat ?
- In what ways does Nosrat present reasoning and evidence?
- In what ways does Nosrat use research to support her claim?