**Abstract**

Brazil nut (*Bertholletia excelsa* Bonpl.) is vital for livelihoods in the Amazon region as a source of income and food, and since it is collected mainly from old-growth forests, it is also a cornerstone for forest conservation. This chapter presents socioeconomic and cultural characteristics of Brazil nut collectors, depicting their production systems and identifying individual perceptions about the effects of this activity on their livelihoods and on forest conservation. We interviewed 119 collectors, organized in associations, cooperatives, or autonomous informal organizations. Collectors live from agriculture, fishing, and forest extractivism, and reported the of use more than 30 forest products, highlighting their refined knowledge on forests. On the other hand, they have little access to formal education and information technology. The collection of Brazil nuts proved to positively impacts livelihoods' capitals, being a key species for forest conservation and maintenance of Amazonian livelihoods. Forests are plentiful in Brazil nut trees and collectors are much more likely to remain in forests, incentivizing their conservation. Moreover, the organization into associations or cooperatives is especially positive to broaden sales options and achieve better market prices, breaking historical cycles where middlemen played a preponderant role in Brazil nut commercialization processes across the Amazon region.

**Keywords:** non-timber forest products, Brazilian Amazon, traditional communities, sustainable livelihoods, Brazil nut tree


*4.4. Hilbert Spectrum*

As indicated in Equation (17), an IMF component can be converted from a time-domain to a frequency-domain component; this process is called Hilbert spectral analysis (Figure 7)

$$X(t) = \sum\_{j=1}^{n} a\_j(t) \exp\left(i \int \omega\_j(t)dt\right) \tag{17}$$

Although the Hilbert transform can process a monotonous trend and consider it a part of a longer amplitude, the remaining energy may be excessively strong, considering the uncertainties of longer-term trends and other low-energy elements and information contained in a high-frequency component. The preceding formula provides a time function for each amplitude and frequency component, and this formula can be expanded using a Fourier expression as

$$X(t) = \sum\_{j=1}^{\infty} a\_j e^{i\omega\_j t} \tag{18}$$

where *aj* and *wj* are constants. Comparing Equations (17) and (18) reveals that the IMF can be represented by a generalized Fourier expansion. Variables within the amplitude and the IF cannot only improve the expansion but also render it applicable to unsteady signals. In terms of the expansion of the IMF, the amplitude and the frequency modulation are clearly separated. The amplitude of the time function and the IF can be combined as the time–frequency–amplitude spectrum; this spectrum is referred to as the Hilbert amplitude spectrum.

**Figure 7.** HHT calculation process.


**5. Conclusions**

tively.

It should be noted that FA has a significant impact on the resistance to chloride ion penetration of SCC. Gnanaraj et al. [93] discovered that FA could greatly enhance its resistance to chloride ion penetration. The studies of Mahalingam et al. [21] and Esquinas et The application techniques and hydration mechanisms of SCMs in SCC were discussed, and the impacts of FA, SF, GBFS, and LP on the microstructure and performance of SCC were reviewed. The major conclusions are as follows:

	- proportion of aluminum phase and predominantly spherical particles; SF primarily contains SiO2 and has a high specific surface area. GBFS mainly contains SiO2 and CaO; LP chiefly consists of CaCO3, and both of them show obvious irregular and angular shapes due to mechanical grinding. The hydration mechanisms of these SCMs in SCC include pozzolanic reaction, alkaline activation, and adsorption effect. Moreover, the filling effect and dilution effect of some SCMs on the paste will con-• The pozzolanic reaction and filling effect of SCMs reduce the porosity of the hardened paste, resulting in a denser microstructure in the interfacial transition zone, thus increasing the durability of SCC. Furthermore, because of the high aluminum phase composition, FA and GBFS are typically capable of improving the resistance to chloride ion penetration and sulfate attack of SCC.

tribute to reducing the porosity and limiting the temperature rise of concrete, respec-

It is worth mentioning that although the employment of multiple SCMs in a composite system may provide a superposition effect, the chemical composition of different SCMs varies widely, and the issues of compatibility may rise. The rules governing the influence of composite SCMs added to SCC are not consistent and require additional investigation.

**Author Contributions:** Conceptualization, Z.L. and D.W.; validation, Z.L., M.A. and D.W.; investigation, L.P.; resources, Z.L.; writing—original draft preparation, L.P.; writing—review and editing, D.W.; visualization, L.P.; supervision, D.W.; project administration, D.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was funded by Natural Science Foundation of China [No. 51478248].

**Acknowledgments:** The authors would like to acknowledge the National Natural Science Foundation of China (No. 51478248).

**Conflicts of Interest:** The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


**Preface to "New Generation Coatings for Metals"**

The world of coatings research is enormous. Coating applications span diverse areas such as nanolayers on single-crystal surfaces to organic coatings for the protection of offshore structures, such as wind turbines and drilling platforms, to heat resistant and self-healing coatings and materials for space applications. The purpose of coatings can probably be divided into two groups, cosmetic and functional. In the former case, the coating simply adds to the aesthetic of the substrate; colored paint for a wall in a house is a good example of a cosmetic coating. Functional coatings serve a purpose other than cosmetic. They can broadly be defined as extending the lifetime of the underlying substrate in a particular environment and under certain stressors. Such examples might include wear-resistant coatings applied to bearings, heat-resistant coatings applied to turbine blades to reduce thermal shock and oxidation in jet engines, corrosion-resistant coatings that prevent metal corrosion, and localized attack on metals. It may also include camouflage coatings where the coating itself disguises the substrate to minimize the risk of physical attack. Stealth coatings would fall into this category. Given the wide range of applications, it is not surprising to discover that there is also a wide range of substrates that require protection through the application of coatings including bio-derived materials, polymers and metals.

The coatings themselves draw from most scientific disciplines such as physics, chemistry, biology, and materials science, adapting many principles from these disciplines for problem-solving in coatings. This brings us to this short book. The reader will not be surprised, given the broad nature of coatings, that the research presented in this book is also of a broad nature. To begin, we look at two papers that investigate metallic coatings on different substrates. Yingying Wang et al. examine AZ91D (a magnesium alloy containing Al and Zn) coatings on steel and magnesium substrates. These coatings are deposited using cold spray technology where the AZ91D powder is accelerated to the target material as high velocity. Cold spray is an emerging technique that shows promise for coating manufacture as well as repair. In the second contribution, Liang Hao et al. use a mechanical plating method to apply Ti-based coatings onto steel balls as part of a wider program of understanding how mechanical plating works. The third paper, by Buchtik et al., explores how improved chemical and physical resistance can be obtained by applying an electroless Ni-P coating to a magnesium substrate. Electroless plating is a chemical process performed in a coating bath. The fourth contribution by Yung-I Chen et al. uses the coatings technique of magnetron sputtering. In this paper, the authors study the structure and hardness of multilayer structures consisting of a 100 nm Cr base layer and a Ru-Zr overlayer.

The next contribution by Merachtsaki et al. examines the corrosion protection of steel using a nanocomposite comprising epoxy and clay nanoparticles modified by organo-ammonium ions. The following paper is an excellent review paper by Taghavikish et al. on ionic and polyionic liquids for corrosion protection. The penultimate paper, by Xiaohui Liu et al., looks at the growth models of plasma electrolytic oxidation (PEO) coatings grown on an aluminum alloy. PEO is another relatively new coating method that promotes oxide formation during the electrical breakdown in an electrolyte. The final paper, by the editor and co-authors, looks at the characterization of the leaching of a new, non-chromate, Li-based inhibitor from a traditional polyurethane-based primer for aerospace applications. In summary, the papers presented in this volume will provide the reader with detailed studies of the breadth and type of work that is being undertaken using a variety of approaches in the field of coatings.


**Antioxidants in Animal Production, Reproduction, Health and Welfare**

Editors

**Youssef A. Attia Woo Kyun Kim Nesrein Hashem Maria de Olivera**

*Editors* Youssef A. Attia Department of Agriculture King Abdulaziz University Jeddah Saudi Arabia

Woo Kyun Kim Poultry Science Department University of Georgia Athens United States

Nesrein Hashem Department of Animal and Fish Production Alexandria University Alexandria Egypt

Maria de Olivera Faculty of Veterinary Medicine Rio Verde University Rio Verde Brazil

*Editorial Office* MDPI St. Alban-Anlage 66 4052 Basel, Switzerland

This is a reprint of articles from the Special Issue published online in the open access journal *Animals* (ISSN 2076-2615) (available at: www.mdpi.com/journal/animals/special issues/Animal Antioxidants).

For citation purposes, cite each article independently as indicated on the article page online and as indicated below:

Lastname, A.A.; Lastname, B.B. Article Title. *Journal Name* **Year**, *Volume Number*, Page Range.

**ISBN 978-3-0365-8969-5 (Hbk) ISBN 978-3-0365-8968-8 (PDF) doi.org/10.3390/books978-3-0365-8968-8**

© 2023 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) license.


**3. Defects**

As we know, BN is a good choice for low-dimensional semiconductors (especially 2D) with remarkable thermal, mechanical, and dielectric properties. Theoretically, BN should exhibit perfect lattice structures free from defects, but as we know, the actual material is marginally different from theoretical models. Similarly, BN has some inevitable structural defects that arise due to the imperfection of the growth/preparation processes. These defects are unintentionally induced because of the dramatic influence over the material's physical properties, even in a low-dimensional state.

#### **3.1 Point defect**

The point defect, known as Stone-Wales (SW), is prevalent in semiconductor materials. It involves the connectivity change of π-bonded carbon atoms leading to their rotation by 90° [45]. This defect forms two separate vertically bonded rings instead of two rings sharing a common edge. This specific structural defect, such as graphene, is common in sp2 -bonded carbon allotropes. Similarly, SW or point defects are observed in BN material with low dimensions [46]. The formation of point defects in BN nanoribbons is due to the structural geometry. The SW defects in BN nanoribbons (zigzag and armchair) are shown in **Figure 5**. These defects decrease the bandgap regardless of BN nanoribbon orientation but maintain ultrawide bandgap behavior (insulating). At the same time, the defect site of this particular nature is far more reactive when compared to the defect-free site in BN nanoribbon [47–49].

Atomic vacancy is also a point defect observed by high-resolution transmission electron microscopy (HRTEM). The HRTEM analysis of BN monolayers reveals triangle-shaped vacancies that have been observed. It is also revealed that the monovacancy of boron (VB) and the monovacancy of nitrogen (VN) coexist in nature. The boron atom has low knock-on energy compared to that of nitrogen. Hence, it favors the formation of boron vacancies rather than nitrogen vacancies [49]. Therefore, VN is not observed during HRTEM observation.

On the other hand, the coexisting vacancies like VB, V3B + N, and V6B + 3N, etc., are evident. However, Alem et al. suggested that besides knock-on damage, there might be other mechanisms of forming coexisting vacancies, such as replacing ejected atoms with nearby atoms [50]. Furthermore, the interlayer distance with a missing boron atom was enlarged, which indicates that the dangling bonds for each N atom might be repulsive to each other. No stable divacancy (VBN) was observed as VBN would immediately transform into V3B + N due to further removal of boron atoms [48].


*6.2.3 Surface topography*

It is stated that surface roughness may enhance adhesion between cell and extracellular matrix. At the same time, too rough surface of the scaffold may exhaust the cell adhesion capability. On the other side, if the scaffold material is too sharp, the cells may get damaged. However, choosing a smooth surfaced scaffold material may require consideration of further modification or coating, as this feature does not facilitate cell adhesion.