**3. Phase "measure"**

In this section, we will define the current state in order to analyze it and to identify the gap between the actual and the desired situations. To do this, we will structure this part in three phases. First of all, we will detail the developed measurement system. Then, we will detail our data collection plan and our experimental data. Finally, we will identify our desired situation and the gap with the current one.

#### **3.1 The measurement system analysis**

#### *3.1.1 Approach description*

Our measurement system aims to define our sequential production and distribution planning approach while evaluating the current situation of the company. The objective is to satisfy POs and ROs within the required deadlines, while minimizing the production, subcontracting, capacity under-utilization, storage and distribution costs.

Our approach is based on two mathematical models that are developed at two different decision levels [21, 22]. The first model focuses on a tactical level of a 6-month horizon with a monthly periodicity and decides on pre-season quantities to be placed internally and with overseas subcontractors with long lead times. Each

time a new order arrives, it is inserted with a rolling horizon in order to be placed optimally on the available resources.

The second operational model considers a monthly horizon with a variable periodicity between 8 and 11 weeks. This model is used to detail tactical confirmed quantities over weeks and to insert new urgent orders arriving through a rolling horizon.

At the operational level, urgent orders with short lead times are inserted progressively. However, when a new order with a long lead time for the pre-season arrives, the tactical model is run and the order is inserted on the rolling horizon to study the possibility of subcontracting it to overseas subcontractors. Thereafter, the production will be refined over weeks using the operational model, if the decision taken at the tactical level affects production internally. This operation is repeated until all orders for the season have been placed.

Our approach results in a production, storage and distribution plan that takes into account the assignments of overseas subcontractors and the assignments of new orders that arrive at the operational level. The latter are detailed by week during the first 2 months. Given the principle of the rolling horizon, decisions taken during the first week are fixed and the related costs are recorded. However, decisions taken in following periods will be revised once the model has been run in the second week.


**2. Conditions for SP generation**

species, radicals, and UV radiation produced in an atmospheric pressure plasma [1]. The most important merits of the SPP forthe NPs synthesis, as compared with chemical methods, consist in the short processing time (in the range from few minutes to several tens of minutes), preparation in room temperature and pressure conditions, and low energy of plasma. The novelty of the SPP method used in our laboratory consists in the fact that plasma operates in glow discharge limits, offering a suitable medium to control the chemical reactions inside the solutions [10, 11]. This is possible because plasma offers a new reaction medium, where hydrogen, hydroxyl, and oxygen radicals are produced, where the hydrogen radical is the most responsible for the reduction reaction of the gold ion to the neutral atom, and therefore a reduction agent is not necessary. The SPP method seems well‐suited for the NPs synthesis offering the possibility to control the size by controlling the surrounding chemistry of the gold

Micro-Nano Mechatronics — New Trends in Material, Measurement, Control, Manufacturing and Their Applications in

NPs, adding thus another level of utility of this procedure to material science [12, 13].

structures which can improve the catalytic activity of fuel cells [14].

water [1].

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ces between plasma and gas, and gas and liquid.

nanomaterials with enhanced catalytic activity [1, 14].

SPP was successfully used for loading metal NPs on carbon materials to prepare composite

Many other applications of SPP in nanomaterial technology have been performed in our group related with template removal in mesoporous silica synthesis process [15], decomposition of organic dyes or compounds [16, 17], surface modification of metals [19], and sterilization of

**Figure 1.** Model of Solution Plasma. The main regions are: plasma gas phase, gas phase, liquid phase and the interfa‐

In the followings we will discuss about the conditions for SP generation [16, 19‐21], the role of radicals, ions and surrounding chemistry in NPs synthesis [11, 12, 17, 22], and synthesis of A typical experimental set‐up for the generation of SP, with time‐dependent electrical and optical diagnostics of plasma and synthesis of nanomaterials is shown schematically in Figure 2. A typical power supply for SP generation has the following characteristics: bipolar pulse type with a maximum voltage and current of 5 kV and 10 A, respectively, a variable repetition frequency in the range from 5 to 60 kHz, and a variable pulse width from 500 ns to 3 μs [10, 16, 18‐20].

**Figure 2.** Typical experimental set-up for SP generation, with time-dependent electrical and optical diagnostics of plasma, and synthesis of nanomaterials.

We investigated the dependence of SP characteristics on the inter‐electrode distance. In SP, the formation of differentradicals, the excited atoms and molecules are strongly influenced by the geometry and the input electrical power in the system. Figure 3 shows various regions of SP depending on the inter‐electrode distance and the applied pulsed high voltage. Typicalregions are the glow discharge regime, when the inter‐electrode space is less than 2 mm and the peak voltage is more than 2 kV, the corona discharge regime, when the inter‐electrode distance increases and the peak high voltage is also high, and the pre‐breakdown regime where electrochemical reactions dominate [20].

In nanomaterials processing, an important factor consists in controlling of the solution plasma stability. The value of pH and the conductivity of the solution also determine the operation regime of SP. In the diagram from Figure 4 various conditions of plasma determined by solution conductivity, bipolar pulse width and frequency, generate a glow or an arc discharge. If the solution conductivity is high, more than 1 mS/cm, the ionic current through the liquid is high, and at the same input electrical power, plasma is instable, if the pulse width is smaller

than 2 μs. If the pulse width increases, the input electrical power increases and even the solution conductivity is high, a stable glow discharge can be obtained.

**Figure 3.** Dependence of SP characteristics on the inter-electrode distance and the applied peak high voltage.

**Figure 5.** (a) Optical absorption spectra of the OH radical measured in HCl, KCl, and KOH solutions, on the positive applied voltage, under the same experimental conditions (discharge voltage of 700 V, frequency of 25 kHz, and pulse width of 4 μs). (b) The time evolution of the OH radical density measured in HCl, KCl, and KOH solutions, under the

The optical absorption spectra of the OH radical measured in different solution with HCl, KCl, and KOH, under a positive value of the high voltage, and the corresponding time‐ dependent signals of the emission line of the OH radical, are represented in Figure 5 (a) and (b), respectively. The OH radical number density measured by broad band absorp‐

voltage pulses were applied to the electrodes. KOH is highly basic and can be an impor‐ tant source of hydroxyl radicals, but in this experiment the density was the lowest for this

The main chemical reactions responsible for the generation of the reactive species in SPP

H2O → ∙H + ∙OH 2H2O → O2 + 2H2 O2 → 2∙O O2 → 2∙H H+e → H\* + e O+e → O\* + e

) when positive

Synthesis of Nanomaterials by Solution Plasma Processing 113

(1)

same experimental conditions above mentioned. Lines are used as guides for the eyes.

) [24].

type of solution (~5x1016 cm‐3

are [4, 5]:

tion spectroscopy was highest for the HCl solution plasma (2x1017 cm‐3

**Figure 4.** Influence of solution conductivity and input electrical parameters of the pulsed power supply on SP stability. Different operation regimes of SP: glow discharge and arc discharge. (a) Stability conditions of SPP in a solution of LiCl with 4 mM concentration. (b) Stability conditions of SPP in a solution of LiCl with 40 mM concentration.

Independently of the solution conductivity, if the pulse width is higher than 2.5 μs and the pulsed power supply frequency is 30 kHz, the plasma generated in solution switches fast to arc discharge regime.

The optical emission spectra strongly depend on SP regime working. Corona discharge is characterized by a strong emission of the OH radical as compared with the glow discharge regime, when the inter‐electrode distance is around 1 mm [20].

than 2 μs. If the pulse width increases, the input electrical power increases and even the

Micro-Nano Mechatronics — New Trends in Material, Measurement, Control, Manufacturing and Their Applications in

**Figure 3.** Dependence of SP characteristics on the inter-electrode distance and the applied peak high voltage.

**Figure 4.** Influence of solution conductivity and input electrical parameters of the pulsed power supply on SP stability. Different operation regimes of SP: glow discharge and arc discharge. (a) Stability conditions of SPP in a solution of LiCl

Independently of the solution conductivity, if the pulse width is higher than 2.5 μs and the pulsed power supply frequency is 30 kHz, the plasma generated in solution switches fast to

The optical emission spectra strongly depend on SP regime working. Corona discharge is characterized by a strong emission of the OH radical as compared with the glow discharge

with 4 mM concentration. (b) Stability conditions of SPP in a solution of LiCl with 40 mM concentration.

regime, when the inter‐electrode distance is around 1 mm [20].

arc discharge regime.

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solution conductivity is high, a stable glow discharge can be obtained.

**Figure 5.** (a) Optical absorption spectra of the OH radical measured in HCl, KCl, and KOH solutions, on the positive applied voltage, under the same experimental conditions (discharge voltage of 700 V, frequency of 25 kHz, and pulse width of 4 μs). (b) The time evolution of the OH radical density measured in HCl, KCl, and KOH solutions, under the same experimental conditions above mentioned. Lines are used as guides for the eyes.

The optical absorption spectra of the OH radical measured in different solution with HCl, KCl, and KOH, under a positive value of the high voltage, and the corresponding time‐ dependent signals of the emission line of the OH radical, are represented in Figure 5 (a) and (b), respectively. The OH radical number density measured by broad band absorp‐ tion spectroscopy was highest for the HCl solution plasma (2x1017 cm‐3 ) when positive voltage pulses were applied to the electrodes. KOH is highly basic and can be an impor‐ tant source of hydroxyl radicals, but in this experiment the density was the lowest for this type of solution (~5x1016 cm‐3 ) [24].

The main chemical reactions responsible for the generation of the reactive species in SPP are [4, 5]:

$$\begin{aligned} \mathrm{H\_2O} &\rightarrow \cdot \mathrm{H} + \cdot \mathrm{OH} \\ 2\mathrm{H\_2O} &\rightarrow \mathrm{O\_2} + 2\mathrm{H\_2} \\ \mathrm{O\_2} &\rightarrow 2\cdot \mathrm{O} \\ \mathrm{O\_2} &\rightarrow 2\cdot \mathrm{H} \\ \mathrm{H^+e} &\rightarrow \mathrm{H^+e} \\ \mathrm{O^-e} &\rightarrow \mathrm{O}^+ + \mathrm{e} \end{aligned} \tag{1}$$


**2. Cellulose substrates for electronic devices: characterization techniques and properties**

Despite the technological applications of paper, there are few contributions regarding cellulose-based substrates characterization, and its applicability in electronic devices. The device and material requirements often limit the choice of the paper substrate, thus a complete understanding of its characteristics, namely, surface morphology, roughness, thermal stability, flexibility, mechanical strength, and hydrophobicity, is essential to assure the proper device operation.

Paper substrates are generally classified based on their weight or *grammage* and can be divided in three categories, following the suggestion of Tobjörk and Österbacka [43]: Light paper, whose *grammage* is in the range of 12–30 g m−2, or for thickness below 75 µm; standard paper, such as office paper, which is around 80 g m−2 and 100 µm thick; and cardboard (or paperboard), when the *grammage* exceeds 200–800 g m−2, or when the thickness is above 300 µm:

• **Light paper**. In this category, one can place two cellulose substrates that are attracting much attention in the recent years: bacterial cellulose (BC) and nanocrystalline cellulose (NCC).

Bacterial cellulose is a bacteria-produced biopolymer composed of ultrafine nanofibers (<100 nm wide); the major perks of this material, comparing to the nanocellulose obtained from wood, is its purity and crystallinity since it is free of lignin, hemicellulose, and other components present in the vegetable cellulose [64–66]. This material can be obtained from several cellulose-producing bacteria, such as *Gluconacetobacter genus, Agrobacterium tumefaciens*, bacteria of the genera *Pseudomonas*, among others; the cellulose is produced extracellularly since the bacteria excretes the cellulose into an aqueous culture medium, of low molecular weight sugars, directly as nanofibers, which form a porous three-dimensional nanocellulose mesh structure [67–69]. The grown layer is then harvested from the medium, cut and dried.

Nanocrystalline cellulose can be obtained primarily from cotton. NCC membranes are prepared through the acid hydrolysis of cellulose process [70]. Cotton is one of the purest cellulose sources, given its higher amount of cellulose (90 wt%), when compared with other vegetal sources that usually contain a mass fraction between 50 wt% (wood) and 80 wt% (flax or hemp) [40, 67, 71]. These membranes are highly transparent, lightweight, and have a smooth surface [40]. The flexibility of some NCC papers and the unique optical properties of nanocrystalline cellulose open a wide range of cost-efficient applications, for instance, smart labels, RFID, smart packaging, or even as support for bio-applications.

material widely used in the food packaging and beverage industry throughout the world. This material comprises three layers: the pressed cellulose fibers (cardboard, 240 g m−2), an adhesive layer of low density polyethylene (LDPE, 12 g m−2), and the aluminum sheet (6–7 mm). One major particularity is its robustness to withstand harsh environments, as evidenced by its use as substrate for solar cell deposited by plasma-enhanced chemical vapor deposition (PECVD) [48] and as an efficient surface-enhanced Raman spectroscopy (SERS) platform supporting metal nanoparticles arrays fabricated through thin film annealing [73].

Based on this classification, the following sections present a comprehensive characterization overview and comparison between paper samples of each category.

The assessment of the surface morphology of cellulose substrates can be achieved by scanning electron microscopy (SEM) [39], backed by three-dimensional (3D) profilometry [74] and AFM [38], to evaluate the paper surface, dimension of fibers, thickness, and porosity. Other techniques, such as X-ray diffraction (XRD) [40, 41], differential scanning calorimetry (DSC), thermogravimetric analysis measurements (TGA) [40, 41], and Fourier transform infrared (FTIR) spectroscopy [75, 76], provide information regarding the paper structure and contents. This information in turn can help to understand the optical properties (such as transmittance and haze factor), studied by spectrophotometry [40], or the electrical properties of the cellulose fibers and overall electrical behavior of the paper material. One method to study the electrical properties of cellulose is the fabrication of different transistors (with and on paper) [38–41, 74] and its analysis by impedance spectroscopy [38, 40, 41, 74].


**7. References**

214 Urban Development

The ultimate hub for shopping and entertainment – now called the *golden triangle* - is a district in Şişli (S in Fig. 1). Clothing outlets, international brands as well haute couture can be found in the narrow lanes of Nişantaşi and Teşvikiye (Photo 4), the location of the city's *new creative class* (leave Metro at Osmanbey). It is remarkable that shopkeepers, formerly located near the touristic overcrowded Bazaar area are now moving to Nişantaşi with its upper class and international customers. Both the financial quarter and the "golden triangle" enlarge the imagination of Istanbul: they are *new post-modern locations*, spatially

Proceeding southward, the space between the "golden triangle" and the traditional core is not at all an empty place. The fashionable CBD of 1900 south of the Taksim square (T), downgraded up to the 1970s, is now revitalised and a *city of pedestrian avenues* (Photo 3). The surrounding flourishes now as an entertainment quarter with different types of restaurants.

remote from the waterfront city at the Bosphor and the Golden Horn.

Galata bridge and the Golden Horn – the focal point of different intersections

Photo 8. At the Galata bridge 2010. Golden Horn, Focus of Istanbul's "multiple

intersections". Suleimaniye mosque in the background.

Prime Shopping CBD

Fin de Siècle - CBD rediscovered

Aksoy A. (2009): Istanbul's choice: openness. Urban Age Istanbul, 48-51.

(www.isocarp.org/pub/events/congress/2006).

**Part 4**

**Spatial Analysis and Urban Development**