Controlled Synthesis and Characterization of Metal Oxide Nanowires by Chemical Vapor Deposition on Silicon and Carbon Substrates

Nanotechnology and nanomaterials have attracted considerable interest and are predicted to revolutionize many materials and technologies that we use in everyday life. In the past few years, significant research has focused on one dimensional metal oxide nanostructures due to their unique properties and potential applications in various fields from nanoelectronics to energy. However, controlled synthesis of these nanostructures is still a challenge. The objective of this thesis is to synthesize metal oxide nanowires by chemical vapour deposition directly on various substrates. The nanostructures include (i) silicon oxide nanostructures on silicon substrate, (ii) manganese oxide nanostructures on silicon substrate, and (iii) manganese oxide nanostructures on carbon paper substrate. Firstly, silicon oxide nanowires were synthesized on silicon substrate by a VO2 assisted chemical vapor deposition. Networked features of silicon oxide nanowires were found. Systematic study on the nanowire growth has indicated that morphology and composition of the final products are considerably sensitive to the catalyst components, reaction atmosphere and temperature. These results will help in better understanding the growth process of silicon oxide nanowires. Secondly, manganese oxide nanostructures were synthesized on silicon substrate by chemical vapor deposition method. It was found that MnO nanowires are high density and single crystalline with average diameter of 150 nm. These nanowires were characterized using FESEM, EDX, TEM and XRD. The synthesis process and effects of growth parameters such as temperature, heating rate and source/substrate distance on the morphology, composition and structure of the products were systematically studied. Finally, manganese oxide nanostructures were synthesized on carbon paper substrate by chemical vapor deposition method. It was revealed that manganese oxide nanowires and nanobelts can be selectively grown on carbon paper substrate by using a catalyst (gold) assisted or catalyst free thermal evaporation of manganese powder under an argon gas atmosphere. Various effects of growth parameters such as temperature, catalyst and buffered substrate on the growth product were also systematically investigated by using SEM, TEM and XPS

The influence of symptom attributional style and beliefs about viruses on the reporting of symptoms during and after infection

Previous research has found that attributional style and beliefs people have about viruses can be related to symptom reporting and presentation. Especially in the area of chronic fatigue it has been shown repeatedly that patients' attribution of their illness is related to a worse outcome. This study investigates the influence of symptom attributional style and beliefs about the power of viruses on symptom reporting in people who think they suffer from influenza, using the Symptom Interpretation Questionnaire (SIQ) and the Viral Infection Research into Attitudes Scale (VIRAS). A visual analogue scale was used to measure the number and severity of physical and psychological symptoms of influenza. A follow-up was carried out to measure levels of fatigue after illness, using the Fatigue Scale. Results are presented and discussed, and conclusions are drawn

A Preliminary Study of a Job Analytic Inventory Derived From a Behavioral Consistency Method for Assessing Intrinsic Motivation

The research question for this study asked if the Job Specifications Inventory (JSI) had acceptable internal reliability and an ability to differentiate among occupational groups. The JSI was designed to have subject matter experts rate the importance of skill, content, context, relationship and work focus requirements of jobs or occupations. The JSI used a taxonomy of 268 behavioral elements derived from the content analyses of satisfying achievements reported by a large, diverse clientele. A clinical-type behavioral consistency method was used to extract performance dimensions from clients\u27 achievements to build the taxonomy. The achievement-based taxonomy was seen as potentially enhancing productivity for employers and job satisfaction for employees. The JSI was intended to be used in conjunction with behavioral consistency methods to address individual and organizational problems associated with person-job fit. The relationship between persons and jobs was viewed as having important consequences for individuals, organizations and society. Person-job fit has been linked to employment outcomes associated with productivity, job satisfaction, and work-related stress. A content validity strategy guided JSI development to support fairness and to avoid adverse impact in employment decisions. The JSI was administered to 614 subject matter experts in seven occupational groups--certified public accountants, civil engineers, elementary teachers, insurance sales agents, musicians, personnel managers, and secretaries. Internal reliability estimates ranged from.96 to.98 across occupational groups and from.72 to.96 for JSI parts by occupation. Ward\u27s cluster analysis method suggested a seven-cluster solution against the seven occupational groups used as external classification criteria, but occupational overlap did occur within clusters. The 268 JSI variables were reduced to 38 scales and examined by factor analysis for structural properties. Seven factors were identified with loadings above.40 and used in further evaluation. Analysis of variance found significant differences in scores among occupational groups, clusters and JSI parts. Multiple comparison tests showed significant interaction effects among occupations and clusters by JSI parts and by JSI factors. Results suggested that the JSI displayed acceptable internal reliability and showed discriminating ability to differentiate occupational groups. The statistically significant differences in ratings among groups and clusters were attributable to the structural properties of the inventory and provided evidence for construct validity. The JSI could have utility for managers in behavioral description interviewing to enhance selection and placement decisions. Additionally, individuals could use the JSI to analyze job specifications for strengthening career decisions. Future use could involve the definition of important worker specifications in occupations to enhance mobility for workers and transportability of skills for employers

Synthesis of silicide nanomaterials using chemical vapour deposition method

Recent research has evidenced that nanotechnology may bring about a material revolution which sweeps through different scientific fields and leads to dramatic changes in the use of natural resources and our everyday life. Compared to their bulk counterparts, the nanomaterials may exhibit significantly improved physical properties by shrinking their size to nanometer scale. Metal silicide are distinguished by their features of combining advantages of both metals and semiconductors which promises superior performance various fields. Despite the progress in the synthesis methods of nanomaterials, it still remains a big challenge in controlled synthesis of 1D silicide nanostructures due to the difficulties of well-controlled synthesis conditions. In this study, synthesis process of NiSix and CoSix with different morphologies using CVD method have been analysed and determined. Synthesis of different structures of NiSix on a number of substrates has been investigated. The mechanisms behind the growth of these nanostructures have been studied for better understanding of the synthesis of these silicides. The detailed characterization techniques such as SEM, TEM and XRD were used

Controlled Synthesis of One Dimensional Nanostructured Materials and Their Applications as Catalyst Supports in Proton Exchange Membrane Fuel Cells

Nanomaterials have attracted significant interest in the past decade due to their unique structure and properties compared to their bulk counterparts. Nanomaterials-based solutions can address challenges in various technologies such as proton exchange membrane fuel cells (PEMFCs). PEMFC is an innovative energy conversion technology to directly convert chemical energy to electrical energy by using hydrogen as fuel. However, the current PEMFC system still faces significant technological roadblocks which have to be overcome before the system can become economically viable. A major impediment to the commercialization of PEMFC is the high cost of materials and manufacturing and stability, which is primarily associated with the cost of Pt catalysts and their support in membrane electrode assembly (MEA). One approach in addressing these issues is the controlled synthesis and application of nanostructured Pt-based catalysts and their support in PEMFCs. The objective of this thesis is to synthesize and characterize various nanostructures (e.g. metal oxides and metal silicides or composites) and evaluate their performance as Pt supports used in the PEMFCs. Various advanced characterization techniques such as high resolution scanning and transmission electron microscopy, X-ray absorption spectroscopy and electrochemical characterization methods have been used to understand growth mechanism of obtained nanostructures and their roles in PEMFCs. We also reported the synthesis of WSi2 and Ta5Si3 heterostructures using a low pressure chemical vapor deposition (LPCVD) method. The morphologies of these nanostructures were found to be sensitive to the concentration of reactive species and silica vapor in the CVD chamber. The results indicated that the morphology of WSi2 and Ta5Si3 nanostructures varied from nanowires, networked nanoribbons to nanosheets with the control of the oxygen concentration. A vapor solid growth mechanism based on silica sheath formation was proposed for the synthesis of these nanostructures. To take advantage of unique properties of carbon nanotubes, metal oxide and metal silicides as catalyst support, a new method was developed for the synthesis of composite nanostructures. TiSi2Ox-NCNTs and TiO2-NCNTs nanocomposites were synthesized using a combination of CVD process and magnetron sputtering and their performance as catalyst supports in PEMFCs were studied. Pt nanoparticles deposited on these nanostructures showed enhanced catalytic activity compared to commercial Pt/carbon electrodes. The electronic structure of Pt on the catalyst supports was investigated using X-ray absorption spectroscopy, to obtain insight into the interaction between the catalyst supports and Pt nanoparticles. As an example of well controlled synthesis of nanostructures, one-dimensional tungsten oxide nanostructures (W18O49) have been synthesized using a conventional chemical vapor deposition method (CVD). The morphology of the nanostructures such as diameter and length, were controlled during the synthesis process via sulfur doping. The dependence of morphology, composition and structure of tungsten oxides on the sulfur flow rate has been studied. Further, one step synthesis of tungsten sulfide/tungsten oxide nanocables (WS2/W18O49) have been achieved for the first time using tungsten and sulfur powder as the starting materials. In summary, the research work presented in this thesis aims at contributing to the development of various novel nanostructured catalyst supports and probing the correlation between synthesis approach, fine structure, and catalytic performance of the nanostructures as well as exploring their potential applications in highly active electrocatalysts for PEMFCs

An Analysis of Urban Higher Education CEO\u27s Perceptions of Critical Leadership Behaviors

The research question for this study asked if CEO\u27s (Chief Executive Officers) of urban higher education institutions hold the same values and beliefs as those attributed to business and industry CEO\u27s through the business literature. Through survey methodology, the analysis of urban higher education CEO\u27s perceptions of critical leadership behaviors revealed very similar belief patterns. The primary discrepancies between the research group and their industry counterparts lie in the degree to which critical behaviors are espoused and in the acceptance of transformational leadership as a proactive model for effective organizational change. The responses to the open-ended portion of the questionnaire gave a clear picture of the kinds of training CEO\u27s consider to be important. The Likert scale items revealed that urban education CEO\u27s espouse the transformational leadership concept yet are tentative about empowering staff and aligning the organizational structure to facilitate a participative management model. Entrepreneurship and risk taking activities are embraced somewhat tentatively also which would serve to inhibit creativity and innovation within the organization. The traditional emphasis on academic culture, symbols and the president as leader may be instrumental in encouraging the belief that CEO\u27s should be charismatic and visionary, yet without changing organizational structure and empowering employees, the concept of leadership remains in the traditional domain. It has been established that urban education CEO\u27s do hold similar beliefs as their business counterparts. The literature search also revealed that many environmental and business conditions are also similar. It is therefore recommended that further research be conducted to identify ways in which transformational leadership methods could best benefit the urban higher education milieu

Controlled Synthesis and Characterization of Metal Oxide Nanowires by Chemical Vapor Deposition on Silicon and Carbon Substrates

Nanotechnology and nanomaterials have attracted considerable interest and are predicted to revolutionize many materials and technologies that we use in everyday life. In the past few years, significant research has focused on one dimensional metal oxide nanostructures due to their unique properties and potential applications in various fields from nanoelectronics to energy. However, controlled synthesis of these nanostructures is still a challenge. The objective of this thesis is to synthesize metal oxide nanowires by chemical vapour deposition directly on various substrates. The nanostructures include (i) silicon oxide nanostructures on silicon substrate, (ii) manganese oxide nanostructures on silicon substrate, and (iii) manganese oxide nanostructures on carbon paper substrate. Firstly, silicon oxide nanowires were synthesized on silicon substrate by a VO2 assisted chemical vapor deposition. Networked features of silicon oxide nanowires were found. Systematic study on the nanowire growth has indicated that morphology and composition of the final products are considerably sensitive to the catalyst components, reaction atmosphere and temperature. These results will help in better understanding the growth process of silicon oxide nanowires. Secondly, manganese oxide nanostructures were synthesized on silicon substrate by chemical vapor deposition method. It was found that MnO nanowires are high density and single crystalline with average diameter of 150 nm. These nanowires were characterized using FESEM, EDX, TEM and XRD. The synthesis process and effects of growth parameters such as temperature, heating rate and source/substrate distance on the morphology, composition and structure of the products were systematically studied. Finally, manganese oxide nanostructures were synthesized on carbon paper substrate by chemical vapor deposition method. It was revealed that manganese oxide nanowires and nanobelts can be selectively grown on carbon paper substrate by using a catalyst (gold) assisted or catalyst free thermal evaporation of manganese powder under an argon gas atmosphere. Various effects of growth parameters such as temperature, catalyst and buffered substrate on the growth product were also systematically investigated by using SEM, TEM and XPS

Peranan koleksi wayang dalam kehidupan masyarakat

Jenis-jenis wayang Gedhog, Klitik, Menak, Dupara dan sebagainya, sebagai benda-benda koleksi yang fungsinya ialah: untuk keperluan pertunjukan-pagelaran wayang, pada dewasa ini sudah langka perkembangannya dalam masarakat, meskipun ada beberapa perajin jenis-jenis wayang yang bukan wayang Purwa, yang masih bertahan, namun hasil karya perajin-perajin tersebut hanya ditujukan untuk keperluan hiasan dinding, cinderamata, dan sebagai benda-benda perdagangan. Hal ini disebabkan antara lain karena kurangnya tenaga ahli (dalang) yang dapat mempergelarkan pertunjukan dengan ceritera yang berkaitan dengan jenis-jenis wayang termaksud. Oleh karena itu buku ini bermaksud dan bertujuan untuk menunjang dan menambah serta mengembangkan informasi pengetahuan wayang bagi golongan masarakat yang memerlukan dan belum mengetahui; meningkatkan appresiasi masarakat terhadap hasil karya seni yang berkaitan dengan jenis-jenis wayang tersebut; dan melestarikan serta mengembangkan nilai luhur seni budaya bangsa

Investing in digital color...the bottom line

The purpose of this research is to understand the investment requirements that digital color prospects will face in order to build a digital color business. Printers and prepress firms have been hearing that the cost of ownership is declining, but they need to understand that the business model reaches far beyond cost per page. Not only do digital color printers need to purchase equipment, maintenance support, and consumables, but they need to build the right infrastructure to deliver value-added digital color services to their customers.This research report will examine the various equipment, RIP, and software options print service providers have for migrating into the world of digital color and the associated costs. More importantly, this document will describe what is required to transform digital color equipment into value-added services. Case histories will provide a detailed analysis of the infrastructure needed to make a digital color business thrive. Users will discuss their migration into personalization, Internet services, fulfillment, and distribution. Current owners will also review the investments that were required in digital front-end solutions and software, as well as personnel to sell and support digital color offerings. This white paper is designed to aggregate standard digital color cost elements that are easily identified with infrastructure needs in order to provide a complete investment picture for the world of digital color