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Thesis advisor: Chia-Kuang Tsung / Electrochemical energy storage and conversion applications benefit from the integration of nanostructures into the devices, as they have many more active sites per gram which enables excellent mass utilization of the active species. By controlling the surface of fuel cell catalysts, higher activity and efficiency can be achieved as compared to the bulk counterpart, with multiple catalyst facets of varying activity and efficiency. Nanostructured electrochemical capacitors have enhanced electrolyte diffusion over the surface of the electrode, facilitating high rate capability. Nanostructured materials for energy storage and conversion devices, such as electrochemical capacitors and proton exchange membrane fuel cells, can perform even better with the incorporation of carbon. High surface area carbon can enhance the activity of electrochemical capacitors by improving the conductivity of the electrode and/or enhancing the double layer capacitance. Carbon supports for fuel cell catalysts enable proper dispersion of active material without sacrificing conductivity. The work reported in this thesis is aimed toward improving the performance of electrochemical energy storage and conversion devices through novel incorporation of carbon. Carbon was first used to enhance the performance of electrocatalysts. By wrapping fuel cell catalysts in a porous carbon shell, the activity was increased over its bare and CNT-supported counterparts. The carbon shell synthetic method reported here is a good route to the production of a conductive host for Pd electrocatalysts with good contact and in one step with the formation of the Pd nanoparticles. Carbon was also used to enhance the performance of pseudocapacitors, first by incorporating it into the precursor spray solution in the generation of mesoporous metal oxides and then as a metal-organic framework-derived carbon host with dispersed electrochemically active metal oxides. A carbon network was generated from the pyrolysis of pore directing agents during the decomposition of precursor metal nitrates in the generation of mesoporous manganese oxides in a modified spray pyrolysis approach. The addition of Super P to the precursor spray solution further enhanced the conductivity of the material, enabling the formation of high-performing pseudocapacitors. Lastly, nitrogen-doped carbon cubes produced from thermally-treated parent ZIF-8 cubes were tested as electrochemical capacitors and found to have higher specific capacitance than the nitrogen-doped carbon generated from the parent ZIF-8 rhombic dodecahedra. ZIF-67 cubes were then thermally treated to yield cubic nitrogen-doped carbon hosts for the generated cobalt nanoparticles. Once the cobalt particles were oxidized, the cobalt oxide/carbon hybrid structure exhibited the best pseudocapacitive performance of the ZIF-derived carbon materials tested, exhibiting high specific capacitance and good capacitance retention with increased scan rates and prolonged cycling. Each of the materials tested for electrochemical energy storage and conversion saw an enhancement in performance with the addition of carbon. The results reported here illustrate the importance of carbon in electrochemical cells and the importance of continuing research to modify and improve the methods for carbon production and integration. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

This dissertation focuses on the different ways that religion and secularism are understood and articulated through the practices of Lebanese citizens. Situated at the intersections of legal anthropology, theories of secularism and religion, and interdisciplinary studies of the state and gendered citizenship, my research invites us to rethink theories of liberalism, feminism, and secular modernity by demonstrating how they manifest in non-Western contexts. My project thus challenges us to think more critically about the supposed universality of Euro American articulations of secularism, liberalism, and feminism and asks us to reexamine how these categories are circulated and regulated internationally. I study two practices of Lebanese citizenship; religious conversion as an act that moves between different personal status laws, and advocacy for a secular personal status and/or civil marriage law. This advocacy is a crucial part of what I am calling "da`wa secularism," a term that brings into relief the pedagogical aspect of an activism that aims to saturate the public sphere with a "culture of secularism." Both conversion and da'wa secularism are practices that are predicated on and directed towards the Lebanese legal system. Acts of conversion rely on the laws currently in place; advocacy for a secular personal status seeks to reform them. Despite this divergence between these two practices of Lebanese citizenship, both are couched in and discursively reproduce important aspects of the ideological framework of the Lebanese state. These aspects include the secularity of the state, the role the state is supposed to play in ensuring the protection of Lebanon's pluralism, and the state's mandate to buffer citizens from the overreaching of religious personal status institutions. However, conversion reproduces the state's secularity as the universal space which allows a citizen to change religions freely, while activists suggest that this form of secularism is deficient, dangerous, and "not truly" secular. Similarly, acts of conversion reproduce the citizen as a category of practice that is refracted through the registers of personal status and civil/secular laws and within which the latter has ultimate jurisdiction over the former, while advocacy for a secular personal status seeks to produce Lebanese citizens that are only, and entirely, under the jurisdiction of the civil and secular state. At stake are contending views of secularism, religion, and citizenship.

Dentre as inúmeras técnicas de conversão de voz utilizadas atualmente, aquelas baseadas em bancos de filtros wavelet, associadas com redes neurais artificiais,têm se destacado. Este trabalho se concentra em tais técnicas, realizando um estudo que relaciona qual a melhor wavelet para conversão de determinados padrões de voz, apresentando uma análise detalhada de quais são as características que levam a estes resultados. Os testes são realizados com vozes da base de dados TIMIT do Linguistic Data Consortium (LDC). / Dentre as inúmeras técnicas de conversão de voz utilizadas atualmente, aquelas baseadas em bancos de filtros wavelet, associadas com redes neurais artificiais, têm se destacado. Este trabalho se concentra em tais técnicas, realizando um estudo que relaciona qual a melhor wavelet para conversão de determinados padrões de voz, apresentando uma análise detalhada de quais são as características que levam a estes resultados. Os testes são realizados com vozes da base de dados TIMIT do Linguistic Data Consortium (LDC).

A novel variation of Rutherford Backscattering Spectrometry (RBS) has been utilized to measure a high voltage collected on an aluminum target by Direct Energy Conversion. The maximum high voltage on the target was measured to be 97.5 kV +/- 2 kV. The resistance of the circuit was then calculated based on the current driving different target voltages. The resistance was calculated to be 199.4GΩ +/- 5%. It was shown that by simply measuring the neutral particles’ energy spectra, the voltage on the target and resistance of the circuit can be found with certainty. The experimental data agree well with previous work and with the scattering theory developed. Thus, the capability of RBS has been extended to measure high voltages generated by direct energy conversion; this is something that has not been done before.

Experimental and kinetic modeling studies were carried out on the conversion a wood-oil obtained from high pressure liquefaction of aspen poplar wood to liquid hydrocarbon fuels and useful chemicals in a fixed bed micro-reactor using HZSM-5 catalyst. Similar experiments were conducted using silicalite, H-mordenite, H-Y and amorphous silica-alumina catalysts. <p> Preliminary vacuum distillation studies showed that the wood-oil was made up of volatile and non-volatile fractions. A maximum yield of 62 wt% volatiles at 200 °C, 172 Pa was obtained. The volatile fraction consisted of over 80 compounds. These compounds were comprised of acids, alcohols, aldehydes, ketones, esters, ethers, furans, phenols and some hydrocarbons. The characteristics of the oil showed that it was unstable with time, i.e., its physical properties and chemical composition changed with time probably due to the reaction of free radicals or the oxidative coupling of some of the wood-oil components. However, when the oil was mixed with tetralin, the stability improved. <p> Upgrading studies were first conducted over inert berl saddles in the presence and absence of steam (i. e. non-catalytic treatment/blank runs). Yields of hydrocarbons were between 16 and 25 wt% of the wood-oil. High residue fractions of between 32 to 56 wt% were obtained after processing. Some portions of wood-oil formed a carbonaceous material (char or coke) when exposed to the experimental temperatures. The chars (coke) fraction increased with temperature from 4.7 to 12.5 wt% when processing with steam and 8.0 to 20.4 wt% when processing without steam. <p> Catalytic upgrading studies were first carried out using HZSM-5 catalyst in the presence and absence of steam. The results showed that approximately 40 to 65 wt% of the oil could be converted to a hydrocarbon-rich product (i.e. desired organic liquid product (distillate). This contained about 45 to 70 wt% hydrocarbons with selectivities ranging between 0.47 to 0.88. This fraction was highly aromatic in nature and consisted mainly of benzene, toluene, xylene (BTX compounds) and other alkylated benzenes within the gasoline boiling point range. The yield and selectivities were strong functions of the process time and temperature. A comparison between the two processes, i.e. upgrading in the presence and absence of steam, showed that about 30 to 45 % reduction in coke formation and 5 to 18 wt% increase in organic distillate could be achieved when processing in the presence of steam. These changes were probably due to changes in the rates of cracking, deoxygenation, aromatization and polymerization reactions resulting from the competitive adsorption processes between steam and wood-oil molecules in addition to changes in contact time of molecules. However, the selectivity for hyqrocarbons decreased in the presence of steam. <p> Yields of organic distillate fractions of between 72 to 93 wt% and hydrocarbon yields and selectivities of 44 to 51 wt% and 0.93 to 1.13, respectively, were obtained when wood-oil volatile fraction was upgraded over HZSM-5 after separation from the non-volatile fraction by vacuum distillation. <p> The spent HZSM-5 catalyst could be easily regenerated and reused with little change in its performance. <p> The yields and selectivities for hydrocarbons when upgrading with the other catalysts were between 9 and 22 wt%, and 0.12 and 0.29, respectively for silicalite, 16 and 28 wt%, and 0.22 and 0.28, respectively for H-mordenite, 15.5 and 21 wt%, and 0.17 and 0.21, respectively for H-Y and S.5 and 26.2, and 0.13 and 0.36, resrectively for silica-alumina. Compared to HZSM-5 (yield between 34 and 43 wt%, selectivity of 0.66 to O.SS) these yields and selectivities were much lower. These experiments also showed that the pore size, acidity and shape selectivity of the catalyst influenced the distribution of hydrocarbons in terms of the carbon number. The yield and selectivity of H-mordenite and H-Y (large pore zeolites) were mostly for kerosene range hydrocarbons (C_{<font size=2>9</font>} to C_{<font size=2>15</font>}) and for silicalite and HZSM-5 (medium pore zeolites) for gasoline range hydrocarbons. The hydrocarbon fraction from amorphous silica-alumina did not show any defined distribution. The performance followed the order: HZSM-5> H-mordenite> H-Y> Silicalite, Silica-alumina.<p> With the aid of model compound reactions involving acetic acid methyl ester, propanoic acid, 4-methylcyclohexanol, methylcyclopentanone, 2-methylcyclopentanone, methoxybenzene, ethoxybenzene, phenol, 2-methoxy-4-(2-propenyl) phenol, a synthetic and wood-oil volatile, two reaction pathways were proposed to explain the chemical steps through which the final products of upgrading were obtained. Also, reaction pathways were proposed for each chemical group. These experiments showed that the final products were formed probably through cracking, deoxygenation, olefin formation, oligomerization, hydrogen and hydride transfer, cyclization, isomerization, alkylation and polymerization reactions. <p> Rate models were derived based upon the two reaction pathways and the power law rate model. The rates of formation of products followed the general order: Organic distillate> Hydrocarbons> Residue> Coke> Gas >Aqueous Fraction. Estimates of the values of the kinetic parameters showed that the rate constants ranged between 10^{<font size=2>-6</font>} (aqueous fraction) and 1.81 (volatile fraction), activation energies between 6.7-76.0 x 10^{<font size=2> 3</font>} KJ/Kmol and reaction orders from 0.7 (gas formation) to 2.5 (residue formation). Two mathematical models were derived based on the integral reactor design equation and on the two reaction pathways. This was used to estimate the yield of products. The models predicted the experimental results fairly accurately. Model discrimination showed that the model based on coke and residue formation from both volatile and non­-volatile fractions of the wood-oil best predicted the experimental results.<p> Hydrocarbon selectivity relations which were based on coke, residue and combined coke and residue as undesired products were also derived. Application of these relations showed that lower temperatures and concentrations were most appropriate for higher hydrocarbon selectivity. However, this was at the expense of higher conversions.

Experimental and kinetic modeling studies were carried out on the conversion a wood-oil obtained from high pressure liquefaction of aspen poplar wood to liquid hydrocarbon fuels and useful chemicals in a fixed bed micro-reactor using HZSM-5 catalyst. Similar experiments were conducted using silicalite, H-mordenite, H-Y and amorphous silica-alumina catalysts. <p> Preliminary vacuum distillation studies showed that the wood-oil was made up of volatile and non-volatile fractions. A maximum yield of 62 wt% volatiles at 200 °C, 172 Pa was obtained. The volatile fraction consisted of over 80 compounds. These compounds were comprised of acids, alcohols, aldehydes, ketones, esters, ethers, furans, phenols and some hydrocarbons. The characteristics of the oil showed that it was unstable with time, i.e., its physical properties and chemical composition changed with time probably due to the reaction of free radicals or the oxidative coupling of some of the wood-oil components. However, when the oil was mixed with tetralin, the stability improved. <p> Upgrading studies were first conducted over inert berl saddles in the presence and absence of steam (i. e. non-catalytic treatment/blank runs). Yields of hydrocarbons were between 16 and 25 wt% of the wood-oil. High residue fractions of between 32 to 56 wt% were obtained after processing. Some portions of wood-oil formed a carbonaceous material (char or coke) when exposed to the experimental temperatures. The chars (coke) fraction increased with temperature from 4.7 to 12.5 wt% when processing with steam and 8.0 to 20.4 wt% when processing without steam. <p> Catalytic upgrading studies were first carried out using HZSM-5 catalyst in the presence and absence of steam. The results showed that approximately 40 to 65 wt% of the oil could be converted to a hydrocarbon-rich product (i.e. desired organic liquid product (distillate). This contained about 45 to 70 wt% hydrocarbons with selectivities ranging between 0.47 to 0.88. This fraction was highly aromatic in nature and consisted mainly of benzene, toluene, xylene (BTX compounds) and other alkylated benzenes within the gasoline boiling point range. The yield and selectivities were strong functions of the process time and temperature. A comparison between the two processes, i.e. upgrading in the presence and absence of steam, showed that about 30 to 45 % reduction in coke formation and 5 to 18 wt% increase in organic distillate could be achieved when processing in the presence of steam. These changes were probably due to changes in the rates of cracking, deoxygenation, aromatization and polymerization reactions resulting from the competitive adsorption processes between steam and wood-oil molecules in addition to changes in contact time of molecules. However, the selectivity for hyqrocarbons decreased in the presence of steam. <p> Yields of organic distillate fractions of between 72 to 93 wt% and hydrocarbon yields and selectivities of 44 to 51 wt% and 0.93 to 1.13, respectively, were obtained when wood-oil volatile fraction was upgraded over HZSM-5 after separation from the non-volatile fraction by vacuum distillation. <p> The spent HZSM-5 catalyst could be easily regenerated and reused with little change in its performance. <p> The yields and selectivities for hydrocarbons when upgrading with the other catalysts were between 9 and 22 wt%, and 0.12 and 0.29, respectively for silicalite, 16 and 28 wt%, and 0.22 and 0.28, respectively for H-mordenite, 15.5 and 21 wt%, and 0.17 and 0.21, respectively for H-Y and S.5 and 26.2, and 0.13 and 0.36, resrectively for silica-alumina. Compared to HZSM-5 (yield between 34 and 43 wt%, selectivity of 0.66 to O.SS) these yields and selectivities were much lower. These experiments also showed that the pore size, acidity and shape selectivity of the catalyst influenced the distribution of hydrocarbons in terms of the carbon number. The yield and selectivity of H-mordenite and H-Y (large pore zeolites) were mostly for kerosene range hydrocarbons (C_{<font size=2>9</font>} to C_{<font size=2>15</font>}) and for silicalite and HZSM-5 (medium pore zeolites) for gasoline range hydrocarbons. The hydrocarbon fraction from amorphous silica-alumina did not show any defined distribution. The performance followed the order: HZSM-5> H-mordenite> H-Y> Silicalite, Silica-alumina.<p> With the aid of model compound reactions involving acetic acid methyl ester, propanoic acid, 4-methylcyclohexanol, methylcyclopentanone, 2-methylcyclopentanone, methoxybenzene, ethoxybenzene, phenol, 2-methoxy-4-(2-propenyl) phenol, a synthetic and wood-oil volatile, two reaction pathways were proposed to explain the chemical steps through which the final products of upgrading were obtained. Also, reaction pathways were proposed for each chemical group. These experiments showed that the final products were formed probably through cracking, deoxygenation, olefin formation, oligomerization, hydrogen and hydride transfer, cyclization, isomerization, alkylation and polymerization reactions. <p> Rate models were derived based upon the two reaction pathways and the power law rate model. The rates of formation of products followed the general order: Organic distillate> Hydrocarbons> Residue> Coke> Gas >Aqueous Fraction. Estimates of the values of the kinetic parameters showed that the rate constants ranged between 10^{<font size=2>-6</font>} (aqueous fraction) and 1.81 (volatile fraction), activation energies between 6.7-76.0 x 10^{<font size=2> 3</font>} KJ/Kmol and reaction orders from 0.7 (gas formation) to 2.5 (residue formation). Two mathematical models were derived based on the integral reactor design equation and on the two reaction pathways. This was used to estimate the yield of products. The models predicted the experimental results fairly accurately. Model discrimination showed that the model based on coke and residue formation from both volatile and non­-volatile fractions of the wood-oil best predicted the experimental results.<p> Hydrocarbon selectivity relations which were based on coke, residue and combined coke and residue as undesired products were also derived. Application of these relations showed that lower temperatures and concentrations were most appropriate for higher hydrocarbon selectivity. However, this was at the expense of higher conversions.

Blue/Green lasers can be applied in a wide range such as high-density optical storage, display, biomedical analysis and under water communications. C-band wavelength conversion is one of the most key technologies in DWDM system. Optical Wavelength converter using nonlinear effect can provide high transparency, subcarrier-multiplexed channels and can be fused easily and directly with optical fiber. These characteristics have more advantages than those of O/E/O methods. In this thesis, periodically poled LiNbO3 (PPLN) crystal fiber for wavelength conversion is grown by LHPG method with high-electric-field bias. The relationship between the polarization inversion and micro-swing is analyzed. For different applications, PPLN crystal fiber need appropriate pitches of polarization inversion to meet quasi phase matching. For example, domain period of 15.45 um is used for tunable blue/green lasers. By means of cascaded SHG/SFG effect, when fundamental power is 100 mW, the internal conversion efficiency of SHG and cascaded SHG/SFG were -9.2 dB and -31.9 dB respectively. The SHG 3-dB bandwidth is 9 nm. While the domain pitch varies from 16.79 um to 25.79 um with 30 nm periodic increment , the simulation shows that the cascaded SHG/SFG 3-dB bandwidth is 65 nm in the range of 1476-1672 nm for fundamental wavelength. Domain period of 18.9 um is used for C-band wavelength converter. By means of cascaded SHG/DFG effect, when the crystal length is 1.8 mm, the effective nonlinear coefficient is 18.2 pm/V, which is 83 % of theoretical value. Conversion efficiency is about -59.3 dB when fundamental power and signal power were 350 mW and 15 mW, respectively.