We are IntechOpen, the world's leading publisher of Open Access books Built by scientists, for scientists

4,700+

Open access books available

121,000+

International authors and editors

135M+

Downloads

Our authors are among the

Top 1% most cited scientists

12.2%

Contributors from top 500 universities

Selection of our books indexed in the Book Citation Index in Web of Science™ Core Collection (BKCI)

## Interested in publishing with us? Contact<EMAIL_ADDRESS>
Numbers displayed above are based on latest data collected. For more information visit www.intechopen.com

## Meet the editor

Sophia Lionaki is a nephrologist with expertise in glomerular diseases of the kidney. She obtained her medical degree from the National and Kapodistrian University of Athens, Greece, in 1996 and her PhD in 2010 from the University of Ioannina. She did a clinical research fellowship in "Autoimmune Diseases of the Kidney" at the University of North Carolina, Chapel Hill, USA, for one year and subsequently worked for the related program

of the National Institute of Health, USA, as a clinical researcher for two years. Her research interests include ANCA vasculitis, lupus nephritis, and primary glomerular diseases in the native kidneys and the renal allograft. She currently works in the Department of Nephrology of Laiko Hospital in Athens, Greece, since 2008 with clinical, research, and teaching responsibilities.

## Contents


**3. Female infertility**

EDCs are thought to affect women's menstrual cycle, estrogen deficiency, infertility, and are also associated with diseases such as polycystic ovary syndrome (PCOS) and endometriosis, spontaneous abortions, birth defects, endometriosis, breast cancer, premature ovarian failure [23, 25]. Female are at a greater risk than men, especially with the rise in environmental estrogens. However, since research on these exposures often tends to focus on male fertility, it is unlikely that EDCs will answer questions about female fertility [25, 81]. Because females are relatively sensitive to estrogens and are heavily exposed to environmental estrogens, women will also be most affected by EDCs. The origin of endocrine disruption hypothesis was related to exposure to estrogens. Literature data also show that long-term and combined exposure to environmental estrogens will have an impact on female fertility. Although it has long been known that female fertility is impaired by estrogen exposure, there are limited data on whether long-term low-dose exposure to environmental pollutants with weak estrogenic effect causes problems such as infertility in women [81].

There is little epidemiological information about trends in female infertility. Data on the effects of EDCs on the female reproductive system and fertility are insufficient. However, it has been suggested that there is a relationship between exposure to EDCs and their long-term effects [7, 81].

#### *Endocrine Disruptors and Infertility DOI: http://dx.doi.org/10.5772/intechopen.104403*

The most common direct or indirect causes of female infertility are endocrine problems. EDCs alter endocrine function through various mechanisms. One of these mechanisms is that these substances directly bind to estrogen receptors and increase aromatase activity, thereby increasing estrogen sensitivity. Another mechanism is that EDCs indirectly lead to an increase in endogenous estrogen production and exert their effects through both receptor-dependent and receptor-independent mechanisms through their effects on gonadotropin-releasing hormone. Both mechanisms result in altered ovarian function by altering endocrine signaling with several processes in ovary and the other reproductive organs [3, 33, 82].

EDCs act on female reproductive hormones and receptors through estrogenic, anti-estrogenic, androgenic, and anti-androgenic mechanisms [23, 25]. Estradiol (E2) plays a very important role in female fertility. The functions of estrogens are mediated primarily by two estrogen receptors: ESR1 (ERalfa) and ESR2 (ERbeta), both of which are widely expressed in cells throughout the female reproductive system [83]. Most EDCs interfere with female reproductive function by activating or inhibiting ESRs. EDCs have different binding affinities to ESRs and therefore exert different effects in ovary. In ovary, the main function of ESR1 is to regulate steroidogenesis in theca cells. On the other hand, the function of ESR2 is granulosa cell differentiation toward FSH, follicle maturation, and ovulation. Many EDCs interfere with female reproductive function by activating or inhibiting ESRs. Different EDCs exert different effects in the ovary depending on their binding affinity to different ESRs [82, 83].

The sensitivity of the developing female reproductive system to estrogens raises the question of whether exposure to EDCs with estrogenic activity (such as heavy metals, pesticides, and cosmetics) can affect the female fertility [81].


**5. Formation of bundle structures in nitrided wire by uniaxial loading**

The nitrided FGSS316 wire is further uniaxially loaded in tensile. The austenitic grains are continuously linked between its nitrided layer and inner matrix. This nitrided layer had influence on the mechanical response of wire since the same elasto-plastic strains are applied to these two regions. Precise microstructure analysis is also made to describe the microstructure evolution of this nitrided wire during the uniaxial loading.

## **5.1 Uniaxial loading procedure**

The uniaxial tensile loading test was performed by using the precision universal testing machine AUTOGRAPH AGS-X 10 kN (SHIMADZU Co. Ltd.). This uniaxial loading was terminated when the maximum applied load reached 6 kN before fatal ductile fracture for microstructure analyses. The applied load and stroke were in situ monitored by the load cell and linear scaler, respectively. The bare FGSS316 wire without nitrided layer has an ultimate strength (σU) of 1.18 GPa at the stroke (δ) of 4.9 mm, or, at the nominal strain (ε) of 0.17.

## **5.2 Microstructure evolution during uniaxial loading at RT**

A normal FGSS316 wire elongates in the tensile direction at room temperature (RT) without significant change of microstructure except for the formation and coalescence of voids near the fatal ductile fracture of wire [31]. Microstructure of high carbon steel wire is sensitive to drawing process since it has a multidimensional microstructure, where each austenitic grain boundary houses pearlite blocks and each block consists of pearlite colony with the same lamellar structure of cementite (or θ-phase) and lamellar ferrite [32]. However, little microstructure

change occurs at the RT in its uniaxial tensile loading. A composite wire also has no microstructure evolution before pop-out of fibers from core matrix [33]. Let us investigate the microstructure at the nitrided layer and in the matrix of wire, respectively, and describe the effect of posterior elasto-plastic straining to nitriding on the microstructure evolution in wire.

**Figure 14** depicts the plastic strain distribution and phase mapping on the lateral and longitudinal cross-sections of nitrided FGSS316 wire, respectively, after uniaxial loading. The retained austenite regions with larger size than fine grained two-phase nitrided layer in **Figure 12** completely disappear at the nitrided layer. Every nitrided layer has homogeneous two-phase microstructure with fine grain sizes. Compared with the plastic strain distribution before uniaxial loading, the whole nitrided layer is uniformly subjected to high plastic straining. This reveals that the applied plastic strains by uniaxial loading drives the synergetic process of inner nitriding at the retained austenitic zones and induces the phase transformation from the retained γ-phase to γ−/α'-phase fine mixture.

The microstructure as well as the phase in the matrix below NFE is modified by this uniaxial loading. Nearly full austenitic phase of matrix before loading changes to mixture of γ-fibers and transformed α'-fibers. As shown in **Figure 14b** and **d**, these α'-fibers with its lateral size of 0.5 μm are aligned along the loading direction to form a bundle structure together with γ-fibers. The volume fraction of these α'-bundles increases from the vicinity of NFE to the depth in matrix. This suggests that the nitrided FGSS316 wire fractures of α'-bundles in ductile at its center when this fraction reaches to the critical maximum.

Let us compare the above phase mapping in matrix with the plastic strain distribution in **Figure 14**. The high plastic straining zones are just corresponding to the α'-fiber zones. This proves that this γ to α'-phase transformation during the uniaxial loading is induced by the high plastic straining of γ-zones. That is, the highly strained γ-grains are plastically strained and aligned along the loading direction to form the γ-fibers. During this microstructure evolution, some of γ-fibers transforms massively to α'-fibers.

The phase transformation and formation of bundle microstructure in the above reflects on the crystallographic structure after uniaxial loading. **Figure 15** depicts the IPF mapping at the nitrided layer and in the matrix on the lateral and

#### **Figure 14.**

*Plastic straining and phase mapping on the lateral and longitudinal cross-sections of nitrided FGS316 wire after uniaxial loading. (a) Plastic strain lateral distribution, (b) phase mapping in lateral, (c) plastic strain longitudinal distribution, and (d) phase mapping in longitudinal.*

**69**

**6. Discussion**

**Figure 15.**

*Micro-/Nano-Structuring in Stainless Steels by Metal Forming and Materials Processing*

longitudinal cross-sections of wire, respectively. The γ-phase matrix before uniaxial loading has crystallographic structure with the average grain size of 2 μm and without preferred orientations. After loading, these γ- and α'-grains are aligned along the loading direction respectively to form α'- and γ-bundles. In particular, most of α'-bundles have unique (111) directions. This might be because the transformed bundles are aligned in the tensile directions under the constrained conditions by the nitrided layer, surrounding the matrix. Each initial γ-grain is forced to deform elasto-plastically only in the tensile direction and to form γ-fibers and γ-bundles since no plastic deformation is allowed in the lateral direction under the confinement of nitrided layer. Some of strained γ-fibers makes massive transformation to α'-fibers; these α'-fibers are assembled into a single α'-bundle with the preferred orientation to (111). After [26, 34], the easiest crystallographic orientation to form

*Nitrogen mapping and crystallographic structure on the lateral and longitudinal cross-sections of nitrided FGSS316 wire after uniaxial loading. (a) Nitrogen mapping in lateral, (b) lateral IPF mapping in ND,*

*(c) nitrogen mapping in longitudinal, and (d) longitudinal IPF mapping in TD.*

this martensitic fibers and bundles is thought to be (111) tensile direction.

suggests that elasto-plastic compatibility is preserved across this interface.

The polycrystalline materials are generally described by the grain boundary characteristics and crystallographic orientation of each constituent grain as well as its grain size [35]. Each grain boundary energy is determined by the misfit orientation angle between adjacent grains. The compatible grain boundary has low energy enough to stack some amount of dislocations; while the incompatible one has high

**Figure 15** reveals that the nitrided layer surrounding the matrix has homogeneous super fine-grained two phase structure after uniaxial loading. No cracks and defects are seen on the nitrided layer surface and in the inside of layer; the fatal fracture of this nitrided FGSS316 wire occurs as the ductile fracture of matrix as explained before. The fine continuous interface between the nitrided layer and the matrix also

*DOI: http://dx.doi.org/10.5772/intechopen.91281*

*Micro-/Nano-Structuring in Stainless Steels by Metal Forming and Materials Processing DOI: http://dx.doi.org/10.5772/intechopen.91281*

#### **Figure 15.**

*Electron Crystallography*

on the microstructure evolution in wire.

tion from the retained γ-phase to γ−/α'-phase fine mixture.

this fraction reaches to the critical maximum.

transforms massively to α'-fibers.

change occurs at the RT in its uniaxial tensile loading. A composite wire also has no microstructure evolution before pop-out of fibers from core matrix [33]. Let us investigate the microstructure at the nitrided layer and in the matrix of wire, respectively, and describe the effect of posterior elasto-plastic straining to nitriding

**Figure 14** depicts the plastic strain distribution and phase mapping on the lateral and longitudinal cross-sections of nitrided FGSS316 wire, respectively, after uniaxial loading. The retained austenite regions with larger size than fine grained two-phase nitrided layer in **Figure 12** completely disappear at the nitrided layer. Every nitrided layer has homogeneous two-phase microstructure with fine grain sizes. Compared with the plastic strain distribution before uniaxial loading, the whole nitrided layer is uniformly subjected to high plastic straining. This reveals that the applied plastic strains by uniaxial loading drives the synergetic process of inner nitriding at the retained austenitic zones and induces the phase transforma-

The microstructure as well as the phase in the matrix below NFE is modified by this uniaxial loading. Nearly full austenitic phase of matrix before loading changes to mixture of γ-fibers and transformed α'-fibers. As shown in **Figure 14b** and **d**, these α'-fibers with its lateral size of 0.5 μm are aligned along the loading direction to form a bundle structure together with γ-fibers. The volume fraction of these α'-bundles increases from the vicinity of NFE to the depth in matrix. This suggests that the nitrided FGSS316 wire fractures of α'-bundles in ductile at its center when

Let us compare the above phase mapping in matrix with the plastic strain distribution in **Figure 14**. The high plastic straining zones are just corresponding to the α'-fiber zones. This proves that this γ to α'-phase transformation during the uniaxial loading is induced by the high plastic straining of γ-zones. That is, the highly strained γ-grains are plastically strained and aligned along the loading direction to form the γ-fibers. During this microstructure evolution, some of γ-fibers

The phase transformation and formation of bundle microstructure in the above reflects on the crystallographic structure after uniaxial loading. **Figure 15** depicts the IPF mapping at the nitrided layer and in the matrix on the lateral and

*Plastic straining and phase mapping on the lateral and longitudinal cross-sections of nitrided FGS316 wire after uniaxial loading. (a) Plastic strain lateral distribution, (b) phase mapping in lateral, (c) plastic strain*

*longitudinal distribution, and (d) phase mapping in longitudinal.*

**68**

**Figure 14.**

*Nitrogen mapping and crystallographic structure on the lateral and longitudinal cross-sections of nitrided FGSS316 wire after uniaxial loading. (a) Nitrogen mapping in lateral, (b) lateral IPF mapping in ND, (c) nitrogen mapping in longitudinal, and (d) longitudinal IPF mapping in TD.*

longitudinal cross-sections of wire, respectively. The γ-phase matrix before uniaxial loading has crystallographic structure with the average grain size of 2 μm and without preferred orientations. After loading, these γ- and α'-grains are aligned along the loading direction respectively to form α'- and γ-bundles. In particular, most of α'-bundles have unique (111) directions. This might be because the transformed bundles are aligned in the tensile directions under the constrained conditions by the nitrided layer, surrounding the matrix. Each initial γ-grain is forced to deform elasto-plastically only in the tensile direction and to form γ-fibers and γ-bundles since no plastic deformation is allowed in the lateral direction under the confinement of nitrided layer. Some of strained γ-fibers makes massive transformation to α'-fibers; these α'-fibers are assembled into a single α'-bundle with the preferred orientation to (111). After [26, 34], the easiest crystallographic orientation to form this martensitic fibers and bundles is thought to be (111) tensile direction.

**Figure 15** reveals that the nitrided layer surrounding the matrix has homogeneous super fine-grained two phase structure after uniaxial loading. No cracks and defects are seen on the nitrided layer surface and in the inside of layer; the fatal fracture of this nitrided FGSS316 wire occurs as the ductile fracture of matrix as explained before. The fine continuous interface between the nitrided layer and the matrix also suggests that elasto-plastic compatibility is preserved across this interface.

#### **6. Discussion**

The polycrystalline materials are generally described by the grain boundary characteristics and crystallographic orientation of each constituent grain as well as its grain size [35]. Each grain boundary energy is determined by the misfit orientation angle between adjacent grains. The compatible grain boundary has low energy enough to stack some amount of dislocations; while the incompatible one has high

energy enough to interact with dislocations [36]. In the metal forming of these polycrystalline materials or in the nitrogen supersaturation process, the dislocations as well as the slipping lines and planes interact with their grains and grain boundaries. In intense rolling, the grains are sheared and deformed to align their crystallographic orientation along the rolling direction and to form the textured microstructure. The applied elastoplastic distortion by rolling works to induce the phase transformation during rolling by high elastic strain energy density, to shear and elongate the grains by the plastic strains, and to spin the grain orientations toward the preferred one along the rolling direction. As reported in [37], the grain size is reduced down to sub-microns by repetitive rolling; due to small misorientation angles between adjacent grains, they are easy to agglomerate into larger grains by heat treatment.

In piercing, the grains near the shearing plane are affected by the applied elastoplastic distortion [38]. The increase of elastic strain energy density during piercing induces the phase transformation. The grains are sheared and fractured along the shearing plain. The original crystallographic structure of work materials is changed to align along the shearing plane by severe spinning with piercing. Although the grains are refined at the vicinity of shearing plain, the misorientation angles among them are small enough to be identified as nearly the same grain. Even in other metal forming processes than two in the above, their mechanical interactions of elastoplastic distortion with crystallographic structure is described by the strain-induced phase transformation, the shear deformation, the grain size refinement as well as the elastic recovery from the elasto-plastically strained state in unloading.

On the other hand, no elastoplastic distortion was directly applied to granular structure by the low temperature plasma nitriding. Instead of this direct straining, a large elastic distortion is induced into the nitrogen supersaturated zones in the work materials by lattice expansion. This distortion reaches to 10%, enough to drive the phase transformation in zones as well as the plastic distortion to compensate for the misfit on the zone boundaries between the nitrogen supersaturated and unsaturated ones. The symmetric component of this distortion works as a shearing strain tensor to form new slipping lines network across the original grain boundary. The asymmetric one drives spin-rotation in each zone to form the zone boundaries with high misorientation angles and to significantly refine the original grain size of work materials. Since those newly built-up zone boundaries play as a nitrogen diffusion path, this process advances concurrently with the nitrogen solute diffusion from the surface to the depth of materials. Since the zone size ranges in the nanometer order, the stainless steel work materials are covered by two-phase, nano-grained, nitrogen steel surface layer. The smallest zone size is determined by the mechanical balancing between the elastic straining in each material supercell and the slip-line formation surrounding it in the nitrogen supersaturation [39]. Precise TEM analyses down to the atomic scale are useful to describe the nitrogen interstitial atom distribution in the supercell [40].

Even when the rolled and pierced steel specimens are uniaxially loaded, their microstructure never changes themselves at room temperature before fracture. Their uniaxial stress-strain curves are determined by the original microstructure of as-rolled and as-pierced materials since no mechanical interaction occurs between the controlled grains by previous metal forming and the applied strain by uniaxial loading. On the other hand, the in situ microstructure evolution takes place during the uniaxial loading of the nitrided FGSS316 wire. The nitrogen supersaturated layer works a double role under this uniaxial tensile loading. The original FGSS316 matrix inside the wire is elastically supported by this nitrided layer. Since the austenitic grains are continuously linked with those in the nitrided layer, the matrix inside the wire is intensely elongated to change its microstructure to two-phase fibrous grains by the uniaxial loading. The microstructure in the as-nitrided layer is also affected by uniaxially applied plastic strains. The retained austenitic grains

**71**

**Figure 16.**

*Micro-/Nano-Structuring in Stainless Steels by Metal Forming and Materials Processing*

with large size in the nitrided layer change themselves to two-phase, fine grains, which are the same as homogeneously nitrided nanostructure before uniaxial loading. This in situ refinement of granular structure in the nitrided layer reflects on the hardness profile. The original hardness of as-nitrided layer is 1400 HV; this is further enhanced up to 1600 HV after uniaxial loading. This proves that nitrogen could diffuse locally to the retained austenitic zones along the slip-lines by externally applied plastic straining and drive the nitrogen supersaturation process in them for refinement of their microstructure. Owing to the elastic constraint by the nitrided layer, the work-hardening process during the uniaxial loading is enhanced in the wire matrix to attain higher ultimate stress (σU); e.g., σU = 1.23 GPa in the

This in situ microstructure evolution by uniaxial loading posterior to nitriding, suggests further possibility of crystallographic control to improve the mechanical properties of metallic works, takes place in the nitrided layer and in the matrix inside without mutual interactions. The microstructure evolution of low temperature nitrided members and parts in the above must be enhanced during warm and hot processing. After recent work on the high carbon steel wire during drawing [41, 42], significant reduction of lamellar ferrite distance as well as free carbon dissociation from the cementite lamellar structure in the perlite colony and block are responsible for high strengthening of high carbon steel wires. This implies that further carbon supersaturation is a key process to drive the in situ evolution to the preferred crystallographic microstructure to higher strength of wire. Owing to the equivalent role between carbon and nitrogen solutes to be working as an interstitial atom in steel [43], local nitrogen mobility from nitrogen supersaturated zone with high nitrogen content to NS-zones with lower nitrogen content could drive the in situ nitrogen alloying process of wire matrix during warm-/hot-drawing and rolling. In this nitriding a priori to metal forming, FGSS316 wire was first nitrided and then uniaxially loaded. How about the plasma nitriding of the rolled AISI304 plate? As shown in **Figure 3**, the nearly full-martensitic phase of rolled AISI304 plate

*Crystallographic structure on the cross-section of the rolled AISI304 plate after plasma nitriding at 673 K for 14.4 ks. (a) IPF mapping in the normal direction, (b) KAM distribution, and (c) phase mapping.*

*DOI: http://dx.doi.org/10.5772/intechopen.91281*

nitrided FGSS316 wire at δ = 5.7 mm or at ε = 0.19.

*Micro-/Nano-Structuring in Stainless Steels by Metal Forming and Materials Processing DOI: http://dx.doi.org/10.5772/intechopen.91281*

with large size in the nitrided layer change themselves to two-phase, fine grains, which are the same as homogeneously nitrided nanostructure before uniaxial loading. This in situ refinement of granular structure in the nitrided layer reflects on the hardness profile. The original hardness of as-nitrided layer is 1400 HV; this is further enhanced up to 1600 HV after uniaxial loading. This proves that nitrogen could diffuse locally to the retained austenitic zones along the slip-lines by externally applied plastic straining and drive the nitrogen supersaturation process in them for refinement of their microstructure. Owing to the elastic constraint by the nitrided layer, the work-hardening process during the uniaxial loading is enhanced in the wire matrix to attain higher ultimate stress (σU); e.g., σU = 1.23 GPa in the nitrided FGSS316 wire at δ = 5.7 mm or at ε = 0.19.

This in situ microstructure evolution by uniaxial loading posterior to nitriding, suggests further possibility of crystallographic control to improve the mechanical properties of metallic works, takes place in the nitrided layer and in the matrix inside without mutual interactions. The microstructure evolution of low temperature nitrided members and parts in the above must be enhanced during warm and hot processing. After recent work on the high carbon steel wire during drawing [41, 42], significant reduction of lamellar ferrite distance as well as free carbon dissociation from the cementite lamellar structure in the perlite colony and block are responsible for high strengthening of high carbon steel wires. This implies that further carbon supersaturation is a key process to drive the in situ evolution to the preferred crystallographic microstructure to higher strength of wire. Owing to the equivalent role between carbon and nitrogen solutes to be working as an interstitial atom in steel [43], local nitrogen mobility from nitrogen supersaturated zone with high nitrogen content to NS-zones with lower nitrogen content could drive the in situ nitrogen alloying process of wire matrix during warm-/hot-drawing and rolling.

In this nitriding a priori to metal forming, FGSS316 wire was first nitrided and then uniaxially loaded. How about the plasma nitriding of the rolled AISI304 plate? As shown in **Figure 3**, the nearly full-martensitic phase of rolled AISI304 plate

#### **Figure 16.**

*Crystallographic structure on the cross-section of the rolled AISI304 plate after plasma nitriding at 673 K for 14.4 ks. (a) IPF mapping in the normal direction, (b) KAM distribution, and (c) phase mapping.*

*Electron Crystallography*

energy enough to interact with dislocations [36]. In the metal forming of these polycrystalline materials or in the nitrogen supersaturation process, the dislocations as well as the slipping lines and planes interact with their grains and grain boundaries. In intense rolling, the grains are sheared and deformed to align their crystallographic orientation along the rolling direction and to form the textured microstructure. The applied elastoplastic distortion by rolling works to induce the phase transformation during rolling by high elastic strain energy density, to shear and elongate the grains by the plastic strains, and to spin the grain orientations toward the preferred one along the rolling direction. As reported in [37], the grain size is reduced down to sub-microns by repetitive rolling; due to small misorientation angles between adjacent grains, they are easy to agglomerate into larger grains by heat treatment. In piercing, the grains near the shearing plane are affected by the applied elastoplastic distortion [38]. The increase of elastic strain energy density during piercing induces the phase transformation. The grains are sheared and fractured along the shearing plain. The original crystallographic structure of work materials is changed to align along the shearing plane by severe spinning with piercing. Although the grains are refined at the vicinity of shearing plain, the misorientation angles among them are small enough to be identified as nearly the same grain. Even in other metal forming processes than two in the above, their mechanical interactions of elastoplastic distortion with crystallographic structure is described by the strain-induced phase transformation, the shear deformation, the grain size refinement as well as

the elastic recovery from the elasto-plastically strained state in unloading.

On the other hand, no elastoplastic distortion was directly applied to granular structure by the low temperature plasma nitriding. Instead of this direct straining, a large elastic distortion is induced into the nitrogen supersaturated zones in the work materials by lattice expansion. This distortion reaches to 10%, enough to drive the phase transformation in zones as well as the plastic distortion to compensate for the misfit on the zone boundaries between the nitrogen supersaturated and unsaturated ones. The symmetric component of this distortion works as a shearing strain tensor to form new slipping lines network across the original grain boundary. The asymmetric one drives spin-rotation in each zone to form the zone boundaries with high misorientation angles and to significantly refine the original grain size of work materials. Since those newly built-up zone boundaries play as a nitrogen diffusion path, this process advances concurrently with the nitrogen solute diffusion from the surface to the depth of materials. Since the zone size ranges in the nanometer order, the stainless steel work materials are covered by two-phase, nano-grained, nitrogen steel surface layer. The smallest zone size is determined by the mechanical balancing between the elastic straining in each material supercell and the slip-line formation surrounding it in the nitrogen supersaturation [39]. Precise TEM analyses down to the atomic scale are useful to describe the nitrogen interstitial atom distribution in the supercell [40]. Even when the rolled and pierced steel specimens are uniaxially loaded, their microstructure never changes themselves at room temperature before fracture. Their uniaxial stress-strain curves are determined by the original microstructure of as-rolled and as-pierced materials since no mechanical interaction occurs between the controlled grains by previous metal forming and the applied strain by uniaxial loading. On the other hand, the in situ microstructure evolution takes place during the uniaxial loading of the nitrided FGSS316 wire. The nitrogen supersaturated layer works a double role under this uniaxial tensile loading. The original FGSS316 matrix inside the wire is elastically supported by this nitrided layer. Since the austenitic grains are continuously linked with those in the nitrided layer, the matrix inside the wire is intensely elongated to change its microstructure to two-phase fibrous grains by the uniaxial loading. The microstructure in the as-nitrided layer is also affected by uniaxially applied plastic strains. The retained austenitic grains

**70**

changed to a mixture of nitrided austenitic and martensitic phases. Since the original martensitic and austenitic peak positions shift to the low angle of 2θ and their peak widths become significantly broad, this mixture composes of the fine grained austenitic and martensitic zones with nitrogen supersaturation.

EBSD was also employed to describe this microstructure change of rolled AISI304 plate after nitriding. As shown in **Figure 16a**, the textured structure of rolled AISI304 completely disappeared and changed to fine-grained structure without preferred crystallographic orientation. This change is driven by high plastic straining in **Figure 16b**; every original grains with and without textures by rolling is plastically strained and spin-rotated by the nitrogen supersaturation to form homogeneous fine-grained structure. As depicted in **Figure 16c**, this fine microstructure consists of two phase with the fraction of martensite by 70%. This dramatic crystallographic structure evolution proves that posterior nitriding to metal forming is useful to further control the microstructure of stainless steels.


**2. The Potential of Invasive Seaweeds**

Due to increasing globalization as well as climate change, the arrival of invasive algae to coastal areas of different regions is becoming more common. However, these are not the only causes of the increased proliferation of these non-indigenous marine species. Other causes, such as those related to the marine industry (aquaculture, fisheries, and marine tourism) must also be considered [18–20]. That is why marine biodiversity is seriously threatened by macroalgae invasions. In fact, macroalgae represent between 10% and 40% of the total number of species introduced into the marine ecosystem [21].

These algae not only cause an environmental problem by displacing other native species, causing a loss of biodiversity, damage in the structure and function of the native ecosystem, and a homogenization of the landscape, but also cause losses in the fishing, recreational sector, and many other industrial sectors related with aquatic environment. However, this abundance can also present opportunities. It is therefore of great interest to find possible applications to give added value to these algae. Furthermore, most of the foods humans eat in the modern world come from a small number of domestic animals and plants widely raised and cultivated, most of them having been introduced voluntarily by humans. One of these applications could be the obtainment of compounds of natural origin.

Because invasive algae pose a serious threat in coastal areas, the interest in developing protocols for the control of these exogenous species is booming, although in parallel, researchers are also trying to develop strategies that allow them to be used as a natural source of secondary metabolites. One of the measures proposed is the eradication of the species, which is a promising solution for areas declared as protected, such as Marine Protected Areas. In this sense, the enormous production of biomass by this type of algae can become a benefit, since it offers the possibility of recycling or reuse at the time of eradication. In any case, it should be taken into account that the impact-control studies do not always allow us to reach an accurate conclusion about the impact of a certain invasive algae, since these studies are designed mainly with the intention of evaluating the anthropogenic impacts, when a control-impact evaluation before and after the invasion would be more accurate [22].

The species of marine algae that are in the top five of "potentially invasive", which means that they meet certain characteristics (relating to the mechanisms of reproduction, growth and defense, resistance to pollution, among others), as well as having a high ecological impact, are, from least to greatest: *Grateloupia turuturu* (as *Grateloupia doryphora*), *Asparagopsis armata, Undaria pinnatifida, Caulerpa taxifolia,* and *Codium fragile* subsp. *tomentosoides* [23]. Some authors [24] classify the factors that favor such invasive attacks of macroalgae in two groups: The abiotic ones, such as salinity and waves, and the biotic ones, such as those related to the competitive abilities of the species. Other authors [25] proposed the Tilman's R\* rule, where R refers to the resources available in an area and R\* to the balance of available resources, from which one can predict where the invasion is favored, since if the R\* of the

endogenous species is greater than that of the exogenous species, the invasion is more likely to occur, and may occur in two ways: The invader needs fewer resources than the resident, or the range of acquisition of resources of the invader is greater than that of the endogenous one. On the other hand, there is a study [24] that discusses about the enemy release hypothesis (ERH), based on the fact that the invader has escaped from its habitat due to the presence of enemies and/or herbivores. This can also be the explanation of why invasive algae tend to have greater resistance to herbivores than native ones. For example, *Fucus evanescens*, presents higher amounts of phlorotannins, compounds known to cause animosity to herbivores [24], than the native species [26].

*Laminaria* sp. (brown algae) show a great adaptability and relocation thanks to their gametophytes, formed by filamentous tufts of approximately 1 or 2 cm. These reproductive structures can be considered as "seed stocks", so their presence is extremely important when colonizing a certain area, as does, for example, the species *Undaria* sp. [27]. Regarding the interactions between the invasive species themselves, information is scarce, so it is an area still to be explored that concerns the entire globe, since invasive algae are not governed by national borders.

Many of these algae contain bioactive compounds that could be contemplated for a wide range of commercial applications like nutrition and pharmaceutical ones. In this regard, invasive algae present great advantages because, according to some authors [20], invasive algae present fast growth rates and biomass accumulation, high levels of repellency against herbivores, and often low levels of epiphytism. Moreover, according to these authors, the low cost of algae farming, along with good economic results and the high demand for products obtained from algae, has led to the intentional introduction of potentially invasive algae in overcoat low-wages countries.


*3.2. Economic Performance Evaluation*

3.2.1. Technical and Financial Analysis of the Drying System

Table 2 presents the financial and technical parameters considered for the operation of the dryer for the case scenario. Based on a drying capacity of 500 kg of maize per batch, it is expected that two batches of drying could be achieved per day. Performance study of the drying system shows that a farmer can dry his maize from an initial moisture content of about 22% (w.b.) to a safe moisture content of 13% (w.b.) within a period of 5 h. This translates to a 720-h operational period of three months from June/July to August/September. This period happens to be the time when over 60% of Ghana's maize produced in the major production season by smallholder farmers along the transition belt of Ghana is harvested. Drying services are critically needed during this period as the harvesting period normally coincides with the onset of rains used for the minor season maize cultivation. Based on the dryer's specified capacity and the drying time, it is estimated that 72 tonnes of maize (554 bags) are expected to be processed within the operational period of three months in a year.

**Table 2.** Technical and financial parameters considered for the business model proposed in the study.

Furthermore, according to MoFA-SRID [13], most smallholder maize farmers in Ghana cultivate an estimated average farmland size of 2 ha at an average yield of 1.5t/ha, correspond to 3 tonnes of maize produced by a farmer in a cropping season. This quantity of maize is projected to be dried within three operation days of the dryer. This means the dryer would be available to other smallholder maize farmers who otherwise will use the unreliable open-sun method for drying their maize. In that regard, about 24 smallholder maize farmers (72 tonnes of maize ÷ (2 ha/smallholderfarmer × 1.5 tonnes of maize/ha)), therefore, could rely on the dryer for their drying services within the operational period used for the case scenario.


**1. Introduction**

Influenza A virus (IAV), the causative agent of influenza, is a major pathogen that causes public health problem and socioeconomic burden world-wide. With waterfowl as the primary reservoir, the virus is able to infect a wide variety of birds and mammals, including humans. Due to this trait, zoonotic spillovers occur occasionally and can lead to pandemics with severe consequences for the human population [1,2]. The avian-origin H5N1 and H7N9 subtypes of influenza viruses are recent examples of animal viruses that acquired the potential to infect and cause disease in humans. H5N1 IAV are often highly pathogenic (HP) avian influenza viruses. In 1997 in Hongkong, six people died out of 18 confirmed human cases with HP H5N1 virus infection [3]. In 2003, novel H5N1 IAV genetic variants circulated in Southeast Asian countries, which led innumerable poultry to death and caused sporadic human infections in the following years. By the end of 2017, 860 laboratory confirmed cases of H5N1 IAV infection from 16 different countries, resulting in 454 deaths, had been reported to the World Health Organization (WHO) [2]. Influenza A viruses mutate easily because of their segmented RNA genome, making it difficult to produce a timely and sufficiently effective vaccine to prevent the potential epidemic outbreaks. Therefore, using anti-influenza agents could be a more efficient approach for prevention and treatment at the beginning of outbreak. To date, two types of anti-influenza drugs have been approved. One type pertains to the M2 ion channel inhibitors, including amantadine and rimantadine, which block the release of viral RNA into the cytoplasm [4]. The others are neuraminidase (NA) inhibitors, including zanamivir, oseltamivir and peramivir, which prevent progeny virus from being released by their host cells [5,6]. However, it has been reported that most of the circulating IAV strains are resistant to M2 inhibitors and may rapidly develop resistance to NA inhibitors, which limits the use of those licensed drugs [7–9]. Therefore, it is urgently required to develop novel anti-influenza agents preferentially with novel mechanisms of action to combat influenza, especially the HP influenza.

The first and most critical step of IAV infection is viral entry mediated by the interaction of viral envelope protein hemagglutinin (HA) and its receptor on host cell surface [10]. HA forms a trimer including three HA1 and three HA2 subunits. Each HA2 contains a fusion peptide, a soluble ectodomain (SE) and a transmembrane domain [11]. After binding to receptor through HA1, IAV is endocytosed. Within the endosome, increasing acidity, pH 5–6, induces HA2 to undergo an irreversible conformational change, leading to the fusion peptide extruding toward the endosomal membrane, and ultimately fusion of the viral and endosomal membranes [10]. HA2, as a major component of the stem region of HA, is a highly conserved subunit. Consequently, blocking HA2- s conformational change could abolish viral membrane fusion and infection. Hence, HA2 is considered an attractive antiviral target [12,13]. The first discovered compound of this class was tertiary butylhydroquinone [14]. Later, several compounds that act in a similar way were described: BMY-27709, CL-385319, stachyflin and 4c [15–18]. However, these small molecular compounds were reported to display inhibitory effects on H1, H2 and H3 IAV subtypes rather than H5 subtype. Recently, guided by structural knowledge on the interactions of HA and anti-stem broadly neutralizing antibodies, Maria and colleagues successfully developed a small molecule JNJ4796 with the ability to inhibit HA-mediated fusion and protect mice against lethal and sublethal influenza challenges [19]. The potent anti-IAV activity of JNJ4796 further reinforces that HA2 could be a promising drug target for blocking IAV infection.

Pentacyclic triterpenoids (PTs), an abundant natural product in plants, have received considerable attention due to their wide spectrum of antiviral activities against various viruses, such as HIV, IAV and HCV [20–23], and some are already marketed as therapeutic agents or dietary supplements. For example, glycyrrhizin (glycyrrhizic acid) has been used for treating chronic hepatic diseases for over 40 years in China and Japan clinically.

Oleanane acid (OA) triterpene is probably the most well-known member of PTs with noticeable antiviral activities. Echinocystic acid (EA), an oleanane-type triterpene, was reported to have substantial inhibitory activity on HCV entry with EC50 at nanomolar range [24,25]. Zhou reported that a different chemical modification to the C-17-COOH of OA led to Y3 (an OA-acetyl galactose conjugate), which showed strong antiviral activity against H1N1 and H3N2 IAV infections in vitro [13]. Further study indicated that Y3 was able to bind tightly to HA protein, thereby disrupting the interaction of HA with its sialic acid receptor [13]. In our previous study, we used an efficient HIV-based pseudotyping system to screen a semisynthetic saponin library, and discovered that OA saponins with β-chacotriosyl residue at the C-3-OH of OA exhibited excellent inhibitory activity against H5N1 IAV entry [26]. Based on this finding, we further designed, synthesized and evaluated a series of 3-O-β-chacotriosyl oleanolic acid analogs as H5N1 IAV entry inhibitors. We found that the introduction of a disubstituted amide structure at the 17-COOH of OA could significantly improve the selective index while maintaining their antiviral activities in vitro [27]. However, as the previous antiviral evaluation of 3-O-β-chacotriosyl oleanolic acid analogs was based on a pseudotyping system, their inhibitory effects on IAV and mechanisms of action are unconfirmed. In the present study, antiviral activities of OA and its eleven analogs, including four newly synthesized derivatives, against H5N1 virus in A549 cells, were investigated, and their mechanisms of action and antiviral activities against other IAV subtypes based on a representative novel compound OA-10 were further investigated. To our knowledge, this is the first report on anti H5N1 IAV activity of OA derivatives.


**2. Findings**

452 International Perspectives on Global Environmental Change

One of the solutions to increased greenhouse gas emissions is the renewable energy of wind power. Wind power is currently the most rapidly growing energy source in the world (Acciona Energy, 2006; BTM Consult ApS, 2009; Firestone, Kempton, Krueger & Loper, 2005, p. 75; Liebmann, 2003, p. 4; Mercer, 2003, p. 10). Wind farms have been established in many countries to reduce dependence on fossil fuels and, at the same time, to increase the production of renewable energy. Wind turbines can be installed onshore and offshore. In spite of positive effects on the environment, i.e. reducing CO2 emissions (see Section 8.), wind farms have been opposed for environmental reasons: Paradoxically, according to Lothian (2008, p. 196), "while addressing one environmental concern, the system is being opposed because of another environmental concern, namely the perceived negative impact on the environment, particularly on landscape quality". There is, however, a strong commitment of many countries to increase the share of renewable energy and this has resulted in a significant increase in the number of wind turbines. The World Wind Energy Association (WWEA) provides a table showing the added capacity of approximately six

1 USA 35.159 1.200 36.300 2 China 26.010 7.800 33.800 3 Germany 25.777 660 26.400 4 Spain 19.149 400 19.500 5 India 10.925 1.200 12.100 6 Italy 4.850 450 5.300 7 France 4.521 500 5.000 8 UK 4.092 500 4.600 9 Portugal 3.535 230 3.800 10 Denmark 3.497 190 3.700 Rest of the world 21.698 2.870 24.500 Total 159.213 16.000 175.000

The table demonstrates that the use of wind power is on the increase overall. The changes in the table refer to a time of approximately six months. Looking at the near past, in the 1990s, Germany had the fastest growth in the industry, followed by Spain, Denmark and India (European Commission, 1997, table 2.2). The German wind farming industry in 2000 was the second largest in the world (Johnson & Jacobsson, 2000, p. 2), generating the highest amount of wind powered energy in the world (Nelson, 2005, p. 8; Reeves & Beck, 2003, p. 9; Rodriguez et al., 2002, p. 1089). The growing trend for Germany has continued (Macintosh & Downie, 2006, p. 1), however, Table 1 demonstrates that China, the United States of America

Added capacity June 2010 (MW) Total capacity June 2010 (MW)

2009, p. 5).

months (end of 2009 to June 2010):

Position Country Total capacity end

Table 1. Wind Power Worldwide June 2010

2009 (MW)

www.wwindea.org/home/index2.php?option+com\_jce&task=popup&img=imag

and India have overtaken Germany during the last (at least) six months.

Evidence of human influence also has been detected in ocean warming, sea-level rise, continental-average temperatures, temperature extremes and wind patterns. This conclusion is consistent with the observed melting of glaciers and ice sheets (CSIRO,

#### **2.1 The Australian wind power industry – Some facts**

In 2008/09 Australia produced 438 million tonnes (Mt) of raw black coal, 334 Mt of black coal was available for the domestic use and for export (2008 Australian Coal). The CSIRO 2003-2011 finds that

…coal is Australia's largest export and a major contributor to the national economy. It is

the primary fuel for power generation worldwide and provides more than 80% of Australia's electricity supply (CSIRO 2003-2011).

Coal is, however, a major contributor to the world's greenhouse gas emissions. According to the CSIRO 2203-2011, current power technologies account for more than one third of Australia's emissions alone. This means that, on the one hand, the profitable coal export industry has to be considered and, on the other hand, the environment. Taking a long term view, the risk of further CO2 pollution is high and our options are limited. Clarke, who has researched climate change and Australia's wind energy projects for many years, contemplates the belief of many that 'Australia can't make any difference' and summarises their negative attitude as follows:

Australia only produces about 1.5% of the world's greenhouse gasses. If we were to cut our emissions to nothing tomorrow, it would make very little difference to the world. Therefore we would be foolish to risk crippling our economy (Clarke, 2008, p. 8).

Bond (2009) is more specific than the CSIRO regarding the production of electricity and finds that in 2006/2007, "83% of Australia's electricity is produced using coal" (p. 2).

2Please refer to Section 3 for some examples.

Wind Farming and the Not-in-My-Backyard Syndrome: A Literature Review

developers and governments face when planning a wind farm.

**Australia**

projects.

importantly, wind resource.

opponents?

Regarding Australia's Challenge in Relation to Climate Change and CO2 Emissions 455

Clarke (2009) also considers the lack of electricity transmission lines, and anticipates a "shortage of working capital due to the financial break-down" (p. 3). Despite these impediments, it is argued here that 16% wind power representing renewable energy could be improved and that the 1.3% of electricity produced from wind power should be increased. The international comparison regarding electricity produced by wind power is as follows: Denmark produces 19%, Spain and Portugal 9%, Germany 6%, Ireland 6%, USA 1.9% (IEA, 2009, p. 10). What are the barriers in Australia to develop and to use to a greater extend facilities that can provide clean, renewable energy? In 2010 four projects, worth 477 MW of wind power, were abandoned or suspended. Here are some examples of challenges

**3. Case studies – Some challenges when wind farming is considered in**

In 2008, wind energy provided 487,537 Australian households with electricity, which presented 1.3% of national electric demand (IEA, 2009, p. 79), however, as mentioned earlier, more than 80% of electricity (CSIRO) or, more specifically, 83% (Bond (2009, p. 2) was coalfired. Let's look at some of the challenges associated with the development of wind energy

In February 2009 Acciona Energy began generating green power in Waubra (approximately 150 km west-north-west of Melbourne, the capital city of the State of Victoria, and 35 km north-west of Ballarat, Victoria). The wind farm consists of 128 turbines of 1.5MW, the installed capacity is 192MW, offsetting 635,000 tonnes of CO2-e annually (Acciona Project Snapshot). Acciona then wanted to establish another wind farm, Waubra North, close to the township of Evansford. But some challenges emerged: According to Radical Green Watch (February 13, 2010), the Pyreness Landscape Guardians organised a meeting in early 2010. This meeting "brought together sixty wind farm opponents from across the state". At the meeting a petition was signed requesting a moratorium on wind farms until health studies were undertaken. A representative of Acciona, present at that meeting, stated that "the company was still conducting investigations of the site at Evansford". Acciona (Newsletter, June 15, 2011) announced that "its early feasibility work on the site at Waubra North …has indicated a wind farm in that location would not be viable"(p. 1). The company had undertaken investigations in relation to the environment, flora, fauna and, most

The further north you travel from Waubra we found the wind resource to be less viable, primarily because of different topography (Acciona Newsletter, June 15, 2011, p. 1). Interesting here are some political connotations. According to Courtice (July 30, 2011), a former member of the Liberal Party sits on the board of the anti-wind power Waubra Foundation, and a businessman, who was involved in oil, gas and mineral exploration companies, set up the foundation. Did Acciona Energy know about these powerful

Some other issues are worth noting because they relate to issues of NIMBYism. Firstly, there is the deliberate creation of "fear, uncertainty and doubt" (FUD) (Courtice, July 30, 2011) by the opponents of wind energy. FUD undermine an objective debate. Secondly, here are some facts about Acciona and its involvement in the local community of Waubra: Waubra has, according to information on the net, a population of 494, it is not far away from Melbourne and Ballarat, and its football team, the Waubra Kangaroos, has won several

Australia "is the rich world's worst per capita greenhouse gas emitter due to a heavy reliance on ageing coal-fired power stations for electricity generation" (Taylor & Grubel, 9.7.2011, p.1). This is a worrying aspect. Data published by the United Nations Statistics Division (2008a) on carbon dioxide emission shows that Australia is in sixteenth position when the percentage of global total CO2 emission is considered: as a nation, 399,219.00 metric tonnes of carbon dioxide are emitted annually. Per capita Australians emit 18.94 tonnes of CO2 per capita (United Nations Statistics Division, 2008b).

Despite challenges, the present Australian Federal Government is committed to generate 20% of Australia's electricity from renewable energy by the year 2020 for a transition to a low-carbon economy (Combet, 2010, pp. 1-4). Interestingly, Australia was listed twenty third in the world in 2004-2005 for capacity of wind generation (Nelson, 2005, p. 8), but it was the first country to implement a mandatory requirement of energy retainers (MRET), i.e. that there be a certain amount of renewable energy target (Kann, 2009, p. 1; Macintosh & Downie, 2006, p. 1; Mercer, 2003, p. 17; Nelson, 2005, p. 3). Since the inception of MRET, wind power has been the fastest growing source of energy in Australia (Macintosh & Downie, 2006, p. 1; Nelson, 2005, p. 3). Wind power accounts for 16% of the renewable energy market in Australia (Clean Energy Council, 2009), but only 1.3% of its electricity comes from wind power (IEA, 2009, p. 79). Australia has various state based national incentive programs to promote wind energy, there is, for instance, the Green Power national accreditation program, and there are initiatives of the Department of Climate Change (IEA, 2008, pp. 79-84). According to the International Energy Agency, in 2008:

Since 1997, Australian installed wind power has grown by 75% (Clarke, 2008, p. 4) which implies that things are moving into the direction of renewable, clean energy. Garnaut (Update 2011a) recommends that "Australia should be ready to calibrate its emissions reductions proportionately to the global mitigation effort" (p. 13) and that "low emissions technology" should be a vital part of the mitigation effort (p. 39). And Diesendorf (2003/2004), promoting Australian sustainable energy for about twenty-five years, argues that

… in replacing a coal-fired power station with a mix of energy efficiency, wind power, bioenergy and gas, the economic savings from energy efficiency will be so large that they could pay for the additional costs of renewable energy (p. 2).

Australia is a land of wide open spaces, its size is 7.7 million square kilometres, its population is 22,650,000, and in 2001, almost 85% of the population lived within 50 km of the coast line (Australian Bureau of Statistics, 2006). The inside of the country is vast, but this vastness has disadvantages and can, according to Clarke (2010/2011, pp. 4-5), present limits to the development of wind farms:

Australia "is the rich world's worst per capita greenhouse gas emitter due to a heavy reliance on ageing coal-fired power stations for electricity generation" (Taylor & Grubel, 9.7.2011, p.1). This is a worrying aspect. Data published by the United Nations Statistics Division (2008a) on carbon dioxide emission shows that Australia is in sixteenth position when the percentage of global total CO2 emission is considered: as a nation, 399,219.00 metric tonnes of carbon dioxide are emitted annually. Per capita Australians emit 18.94

Despite challenges, the present Australian Federal Government is committed to generate 20% of Australia's electricity from renewable energy by the year 2020 for a transition to a low-carbon economy (Combet, 2010, pp. 1-4). Interestingly, Australia was listed twenty third in the world in 2004-2005 for capacity of wind generation (Nelson, 2005, p. 8), but it was the first country to implement a mandatory requirement of energy retainers (MRET), i.e. that there be a certain amount of renewable energy target (Kann, 2009, p. 1; Macintosh & Downie, 2006, p. 1; Mercer, 2003, p. 17; Nelson, 2005, p. 3). Since the inception of MRET, wind power has been the fastest growing source of energy in Australia (Macintosh & Downie, 2006, p. 1; Nelson, 2005, p. 3). Wind power accounts for 16% of the renewable energy market in Australia (Clean Energy Council, 2009), but only 1.3% of its electricity comes from wind power (IEA, 2009, p. 79). Australia has various state based national incentive programs to promote wind energy, there is, for instance, the Green Power national accreditation program, and there are initiatives of the Department of Climate Change (IEA,

tonnes of CO2 per capita (United Nations Statistics Division, 2008b).

2008, pp. 79-84). According to the International Energy Agency, in 2008:

they could pay for the additional costs of renewable energy (p. 2).

 The size and cost of cranes that are used for turbine erection, Size and weight of components that must be transported by road,

limits to the development of wind farms:

Material fatigue.

Potential for aviation and radar interference,

equivalent to 784,610 cars been taken off the road per year, - total capital investment was A\$2.207 billion Agency (IEA, 2009, p. 81).

Since 1997, Australian installed wind power has grown by 75% (Clarke, 2008, p. 4) which implies that things are moving into the direction of renewable, clean energy. Garnaut (Update 2011a) recommends that "Australia should be ready to calibrate its emissions reductions proportionately to the global mitigation effort" (p. 13) and that "low emissions technology" should be a vital part of the mitigation effort (p. 39). And Diesendorf (2003/2004), promoting Australian sustainable energy for about twenty-five years, argues

… in replacing a coal-fired power station with a mix of energy efficiency, wind power, bioenergy and gas, the economic savings from energy efficiency will be so large that

Australia is a land of wide open spaces, its size is 7.7 million square kilometres, its population is 22,650,000, and in 2001, almost 85% of the population lived within 50 km of the coast line (Australian Bureau of Statistics, 2006). The inside of the country is vast, but this vastness has disadvantages and can, according to Clarke (2010/2011, pp. 4-5), present

that

Clarke (2009) also considers the lack of electricity transmission lines, and anticipates a "shortage of working capital due to the financial break-down" (p. 3). Despite these impediments, it is argued here that 16% wind power representing renewable energy could be improved and that the 1.3% of electricity produced from wind power should be increased. The international comparison regarding electricity produced by wind power is as follows: Denmark produces 19%, Spain and Portugal 9%, Germany 6%, Ireland 6%, USA 1.9% (IEA, 2009, p. 10). What are the barriers in Australia to develop and to use to a greater extend facilities that can provide clean, renewable energy? In 2010 four projects, worth 477 MW of wind power, were abandoned or suspended. Here are some examples of challenges developers and governments face when planning a wind farm.


**Strategies for Sustainable Urban Development—Addressing the Challenges of the 21st Century**

## **Strategies for Sustainable Urban Development—Addressing the Challenges of the 21st Century**

Editors

**Liyin Shen Jorge Ochoa Haijun Bao**

MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade • Manchester • Tokyo • Cluj • Tianjin

*Editors* Liyin Shen Hangzhou City University China

Jorge Ochoa University of South Australia Australia

Haijun Bao Hangzhou City University China

*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 *Buildings* (ISSN 2075-5309) (available at: https://www.mdpi.com/journal/buildings/topical collections/ Sustainable Urban).

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

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

**ISBN 978-3-0365-7356-4 (Hbk) ISBN 978-3-0365-7357-1 (PDF)**

Cover image courtesy of Jose Jorge Ochoa Paniagua

© 2023 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications.

The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND.


*2.3. Solid Biomass-Fuelled Boiler*

For providing steam by solid biomass, it is burned in a modern BMB. The heat, generated in the combustion chamber, is transferred to water via a heat exchanger and evaporated accordingly. The amount of steam to be produced is regulated by the amount of fuel supplied. If the amount is reduced or increased, there is a delay in the supply of steam. Although a reduction in the steam demand results in a lower fuel supply, the remaining fuel in the combustion chamber is still used and provides steam to the system. With an increase of the steam, more biomass is fed into the combustion chamber, which ignites with a delay due to the increased quantity [32]. With these plants a wide range of performance can be covered, whereby strict regulations exist in Germany and plants larger than 1000 kW are subject to legal approval [33]. These legal requirements are caused by the emission of nitrogen oxides and ashes, among other things, whereby large plants must be equipped with special exhaust gas purification filters. Besides, the amount of occurring pollutants depends on the choice of biomass and the moisture content of the fuel [34].

It exists a variety of biomass energy sources, from which wood pellets and chips are most widely used. These are characterised by their good storage properties and their relatively high energy content (5.21 kWh/m³). Irrespective of the energy source, a continuously operated system requires both a corresponding storage area and a supply chain for the fuel. Due to the low energy content of the biomass fuels, a large amount of fuel is required, depending on the plant design. The fuel demand of the BMB *EBM* depends on the steam demand *Esteam*,*demand* for the boiler and the part load efficiency *η* of the operating state of the boiler. This is presented by Equation (1).

$$E\_{BM} = E\_{stam,demand} \cdot \eta (\frac{P\_{BM,partload}}{P\_{BM,max}}) . \tag{1}$$


6. Conclusion

)

For evaluation of the ignition performance, ignition index (Di) of the biomass and biochar was

Table 4. Combustion parameters of agricultural waste biomass samples and their derived biochar.

Figure 3. TG and DTG curve of ground nut shell (GNS) its derived char at different temperatures.

Sample Ti Tm Tb Rmax Di (�10�3

CC 195 300 375 1.09 0.57 CCCh(350�C) 295 395 490 0.55 0.29 CCCh(550�C) ——— 0.51 0.27 CCCh(750�C) 375 530 696 0.38 0.20 CCCh(950�C) ——— 0.19 0.09 GNS 240 310 375 1.12 0.65 GNSCh(350�C) 298 355 400 0.7 0.37 GNSCh(550�C) 375 525 695 0.51 0.27 GNSCh(750�C) 400 505 698 0.4 0.21 GNSCh(950�C) ——— 0.14 0.07

Di ¼ Rmax=ð Þ tmax � ti ,

calculated with the following equation [36]:

214 Energy Systems and Environment

where Rmax is the maximum weight loss rate,

Biochars with upgraded fuel qualities were successfully produced from pyrolysis of agricultural biomass waste (ABW). This study demonstrates the type of feedstocks and pyrolysis temperature strongly stimulus the characteristics of the biochar. Increase in pyrolysis temperature, percentage of yield, VM and H, of all the bio-chars decrease; but FC, C, degree of carbonization, GCV, and pH increase. The combustion behaviors of biochars were distinct from raw agricultural biomass, with increased maximum weight loss, raised the ignition temperature and wide combustion ranges at higher pyrolysis temperatures. The conversion of agricultural biomass wastes by pyrolysis to biochar can be a potential option to utilize these wastes for various sustainable purposes like as a as a substitute of renewable energy sources and which we used as a clean and environment friendly energy source.

Author details

References

1983

Swapan Suman\* and Shalini Gautam

10.1007/978-94-007-2181-4\_12

10.1016/j.indcrop.2013.03.011

10.1016/j.jaap.2004.07.003

\*Address all correspondence to<EMAIL_ADDRESS>
Department of Fuel and Mineral Engineering, IIT (ISM) Dhanbad, India

[1] Limousy L, Jeguirim M, Labbe S, Balay F, Fossard E, et al. Performance and emissions characteristics of compressed spent coffee ground/wood chip logs in a residential stove. Energy for Sustainable Development. 2015;28:52-59. DOI: 10.1016/j.esd.2015.07.002

Biochar Derived from Agricultural Waste Biomass Act as a Clean and Alternative Energy Source of Fossil Fuel…

http://dx.doi.org/10.5772/intechopen.73833

217

[2] McKendry P. Energy production from biomass (part 1): Overview of biomass. Bio-

[3] Ajoku KB. Modern use of solid biomass in Africa: prospect for utilization of agro-waste resources in Nigeria. In: Janssen R, Rutz D, editors. Bioenergy for Sustainable Development in Africa. Netherland, ISBN 978–94–007-2180-7: Springer; 2012. pp. 131-146. DOI:

[4] Titiloye JO, Abu Bakar MS, Odetoye TE, et al. Thermochemical characterisation of agricultural wastes from West Africa. Industrial Crops and Products. 2013;47:199-203. DOI:

[5] Jeguirim M, Bikai J, Elmay Y, Limousy L, Njeugna E, et al. Thermal characterization and pyrolysis kinetics of tropical biomass feedstocks for energy recovery. Energy for Sustain-

[6] Demirbas A. Potential applications of renewable energy sources, biomass combustion problems in boiler power systems and combustion related environmental issues. Progress in Energy and Combustion Science. 2005;31:171-192. DOI: 10.1016/j.pecs.2005.02.002 [7] Campbell I. Biomass catalysts and liquid fuels. Lancaster: Technomic Publishing Co. Inc.;

[8] Ravindranath NH, Hall DO. Biomass, Energy, and Environment- a Developing Country

[9] Demirbas A. Effects of temperature and particle size on bio-char yield from pyrolysis of agricultural residues. Journal of Analytical and Applied Pyrolysis. 2004;72:243-248. DOI:

[10] Bridgewater AV. Renewable fuels and chemicals by thermal processing of biomass. Chemical Engineering Journal. 2003;91:87-102. DOI.org/10.1016/S1385-8947(02)00142-0

able Development. 2014;23:188-193. DOI: 10.1016/j.esd.2014.09.009

Perspective from India. Oxford: Oxford University Press; 1995

resource Technology. 2002;83:37-46. DOI: org/10.1016/S0960-8524(01)00118-3

#### Symbols and nomenclature


**2.18 The Bundesambt für Strahlenschutz (BfS, German, 2009)**

According to the German Federal office for radiation protection (BfS) recent studies have failed to demonstrate effects of mobile phone radiation on human fertility. No adverse effects were found on testes and sperm cells. The few papers that showed such effect(s) were considered of low or no scientific value. Experiments on animals have not shown relevant effects whereas *in vitro* studies only showed effects in case of thermal exposure conditions.


**5. Discussion**

### *5.1. Vacuum Arc Commutation Coe*ffi*cient*

Compared to the theoretical analysis and experiments above, it is easy to find that the experimental results can better match the theoretical Formulas (9)–(12). This shows that Formulas (9)–(12) can better reflect the influence of the main parameters, such as the vacuum arc voltage *Uarc*, final commutation current *Ice*, on-state resistance *Rs*, and stray inductance *Ls*, on the vacuum arc commutation characteristics. Meanwhile, according to Formulas (11) and (12) and Figures 6, 8, 13c and 15c, the ratio *k* of *Uarc-avg*-*Usi* to *RsIce* is a key parameter that a ffects *Tc*; and according to Formula (10), it is necessary to ensure that *k* > 1 so that the current can be commutated to the SS branch. Overall, *k* is a very important parameter during the vacuum arc commutation. Therefore, this paper defines *k* as the vacuum arc commutation coe fficient.

According to Figures 6, 8, 13c and 15c, when *k* is small, *Tc* will increase significantly. Therefore, in order to reduce *Tc*, the value of *Uarc-avg* − *Usi* should be increased or the value of *RsIce* should be decreased. The main method of increasing the value of *Uarc-avg* − *Usi* is to increase the vacuum arc voltage. Applying an external magnetic field and connecting multiple MSs in series are currently common methods of increasing the arc voltage [25,26]. The main method to reduce the value of *RsIce* is to reduce the on-resistance *Rs* and final commutation current *Ice*, but reducing *Ice* will reduce the interrupting ability of NHCB. The method to reduce the on-resistance *Rs* is to select FPEDs with low on-resistance or to increase the number of parallel FPEDs [27,28]. Meanwhile, it can be seen from Formula (9) and Figure 11 that reducing the stray inductance *Ls* in the SS is also an e ffective method to reduce *Tc*.

### *5.2. Influence of the Main Parameters on the Vacuum Arc Voltage*

It can be seen from the experiment that when the parameters *Ls*, *Ice*, and *Rs* increase, not only *Tc* increases but the vacuum arc voltage also increases, which is consistent with the positive feedback characteristics of the vacuum arc voltage. This can explain the sudden drop of the vacuum arc voltage in Figure 14, before the IGBT module is turned on, the vacuum arc commutation is very di fficult, so the vacuum arc voltage at this time is higher. When the IGBT module is turned on, the di fficulty of vacuum arc commutation decreases rapidly, so the vacuum arc voltage also decreases accordingly. Meanwhile, to better describe the influence of parameters *Ls*, *Ice*, and *Rs* on *Tc*, in the future work, the influence of the parameters *Ls*, *Ice*, and *Rs* on the vacuum arc voltage should be considered in Formula (9).

Although this paper focuses on NHCB, it is also applicable to other devices that use vacuum arc commutation, such as fault current limiters [29,30]. In the future work, further research will be conducted on other devices that use vacuum arc commutation.


*Article* **Validation of a Dendritic Cell and CD4+ T Cell Restimulation Assay Contributing to the Immunogenicity Risk Evaluation of Biotherapeutics**

**Michel Siegel 1, Guido Steiner 1, Linnea C. Franssen 1, Francesca Carratu 2, James Herron 2, Katharina Hartman 1, Cary M. Looney 1, Axel Ducret 1, Katharine Bray-French 1, Olivier Rohr 3, Timothy P. Hickling 1, Noel Smith 2 and Céline Marban-Doran 1,\***

**Abstract:** Immunogenicity, defined as the ability to provoke an immune response, can be either wanted (i.e., vaccines) or unwanted. The latter refers to an immune response to protein or peptide therapeutics, characterized by the production of anti-drug antibodies, which may affect the efficacy and/or the safety profiles of these drugs. Consequently, evaluation of the risk of immunogenicity early in the development of biotherapeutics is of critical importance for defining their efficacy and safety profiles. Here, we describe and validate a fit-for-purpose FluoroSpot-based in vitro assay for the evaluation of drug-specific T cell responses. A panel of 24 biotherapeutics with a wide range of clinical anti-drug antibody response rates were tested in this assay. We demonstrated that using suitable cutoffs and donor cohort sizes, this assay could identify most of the compounds with high clinical immunogenicity rates (71% and 78% for sensitivity and specificity, respectively) while we characterized the main sources of assay variability. Overall, these data indicate that the dendritic cell and CD4+ T cell restimulation assay published herein could be a valuable tool to assess the risk of drug-specific T cell responses and contribute to the selection of clinical candidates in early development.

**Keywords:** immunogenicity; immunomodulation; biotherapeutics; in vitro T cell assay; assay validation


**2.3. IEC standard 61000-3-6 harmonic distortion limits**

IEC Standard 61000-3-6 specifies the allowable harmonic distortion limits as shown in **Table 3** [4].

**Table 1.** Voltage THD limits according to IEEE 519-2014 [3].

**Table 2.** Current distortion limits according to IEEE 519-2014 [3].

**Table 3.** IEC 61000-3-6 voltage harmonic limits [4].

Measurements were conducted using Hioki 3196 Power Quality Analyzer Meter [8]. The current clamps were installed on transformer one (TX1). Ten-minute average values were recoded over a period of 1 week starting from 17th of January 2012. This study was part of power quality study in MIS [9–12]. A summary of measurements is presented in **Figure 2**.

Harmonics Temporal Profile in High-Voltage Networks: Case Study

http://dx.doi.org/10.5772/intechopen.72568

39

**Figure 2.** Summary of THD measurements at grid station a. (a) Voltage THD (b) current THD.

**Figure 1.** Main interconnected system [7].

**Table 4.** Voltage THD limits according to national Omani codes.


**1. Introduction**

90 Gastrointestinal Endoscopy

[11] Okamura A, Rakugi H, Ohishi M, Yanagitani Y, Takiuchi S, Moriguchi K, Fennessy PA,

[12] Cross AR, Segal AW. The NAPDH oxidase of professional phagocytes-prototype of the NOX electron transport chain systems. Biochim Biophys Acta. 2004; 1657:1-22

[14] Mohiuddin I, Chai H, Lin PH, Lumsden AB, Yao Q, Chen C. Nitrotyrosine and

[15] Singer II, Kawka DW, Scott S, Weidner JR, Mumford RA, Riehl TE, Stenson WF.

[17] Sihvo EI, Salminen JT, Rantanen TK, Rämö OJ, Ahotupa M, Färkkilä M, Auvinen MI,

[18] Elfvin A. Helicobacter pylori associated effects on inflammatory radical formation and

[19] Feagins LA, Zhang HY, Zhang X, Hormi-Carver K, Thomas T, Terada LS, Spechler SJ,

[20] O'Riordan JM, Abdel-latif MM, Ravi N, McNamara D, Byrne PJ, McDonald GS, Keeling

[21] Fitzgerald RC,Onwuegbusi BA, Bajaj-Elliott M, Saeed IT, Burnham WR, Farthing MJ.

[22] Granli T, Dahl R, Brodin P, Bockman OC. Nitrate and nitrite concentrations in human saliva: variations with salivary flow-rate. Food Chem Toxicol 1989; 27:675-80 [23] Wilson KT. Fu S, Ramanujam KS, Meltzer SJ. Increased expression of inducible nitric

[24] Bove M, Ruth M, Lundell L, Ny L. Epithelial barrier integrity and intraluminal nitric

[25] Lin KT, Xue JY, Nomen M, Spur B, Wong PY. Peroxynitrite-induced apoptosis in HL-60

[27] Vieth M, Fiocca R, Haringsma J, Delarive J, Wiesel PH, Tam W, Tytgat GN, Dent J,

sequence in the esophagus. Am J Gastroenterol 2005; 100:1257-64

abnormalities. Gastroenterology 2007; 132:154-165

J Surg Res 2006; 133:143-9

ISBN 978-91-628-7326-4

Semin Cancer Biol 2005; 15:474-83

oesophagus Int J. Cancer 2002;102:551-5

Barrett´s cell lines Am J Physiol 2008; 294:411-7

immunological determinants. Gut 2002; 50:451-9

adenocarcinomas. Cancer Res 1998; 14:2929-34

[26] Babior BM. Phagocytes and oxidative stress. Am J Med. 2000; 109:33-44

discrete endoscopic lesions. Dig Dis 2004; 22:208-12

Physiol Scand 2005; 183:211-8

cells. J Biol Chem 1995; 270:16487-90

of monocytes to macrophages. J Hypertens 1999; 17:537-545

[13] Klebanoff SJ. Myeloperoxidase. Proc Assoc Am Physicians. 1999; 111:383-9

associated esophagitis induces endogeneous cytokine production leading to motor

Higaki J, Ogihara T. Upregulation of renin-angiotensin system during differentiation

chlorotyrosine: clinical significance and biological functions in the vascular system.

Expression of inducible nitric oxide synthase and nitrotyrosine in colonic epithelium in Inflammatory bowel disease. Gastroenterology 1996; 111:871-885 [16] Maley CC, Reid BJ. Natural selection in neoplastic progression of Barrett's esophagus

Salo JA. Oxidative stress has a role in malignant transformation in Barrett´s

angiotensin II receptors in the stomach. Thesis University of Gothenburg 2007.

Souza RF. Mechanisms of oxidant production in esophageal squamous cell and

PW, Kelleher D, Reynolds JV. Proinflammatory cytokine and nuclear factor kappa-B expression along the inflammation-metaplasia-dysplasia-adenocarcinoma

Diversity in the oesophageal phenotypic response to gastro-oesophageal reflux:

oxide synthase and cyclooxygenase-2 in Barrett´s esophagus and associated

oxide production in response to acid perfusion of the ferret oesophagus. Acta

Edebo A, Lundell L, Stolpe M. Radial distribution of dilated intracellular spaces of the esophageal squamous epithelium in patients with reflux disease exhibiting Recently, nonoperative treatment such as chemotherapy or radiotherapy has commonly been performed for submucosal carcinoma of the esophagus. Although endoscopic mucosal resection1)2) (EMR) or endoscopic submucosal dissection3) (ESD) is usually done as curative treatment for mucosal cancer of the esophagus, the efficacy of multimodal therapy combined with EMR/ESD for esophageal squamous cell carcinoma (SCC) with submucosal invasion is controversial.

At our hospital, several patients who had SCC with submucosal invasion received multimodal therapy combined with EMR or ESD, and the results are reported here.


**5. Conclusions**

This review focused on the potential uses of biochar in faecal sludge management (FSM) practices in most developing countries relying on pit latrine sanitation systems. Initially, the designs of pit latrines and the potential ways pollutants may migrate towards water resources without biochar amendments were outlined from previous literature. To understand the pollutant pit latrine leaching threat, the composition (heavy metals and inorganic and organic contaminates) of the stored in situ faecal excreta is important. Possible ways were explored on the effectiveness of biochar use in aqueous waste contaminant adsorption. The physical and chemical properties of biochar mostly determine its adsorption ability as an adsorbent in faecal waste management. Potential challenges in the adoption of biochar in faecal sludge management were also reviewed. Motivation can also be necessary to encourage communities using latrines to adopt biochar as an alternative low-cost carbon-rich absorbent for faecal sludge treatment. Biochar has high potential to effectively treat faecal sludge and control the migration of pit latrine pollutants.