Spectroscopic investigations of N-benzylideneanilines

Thesis--University of Tsukuba, D.Sc.(A), no. 46, 1980. 1. 3

Thermal Expansion in Layered NaxMO2

Layered oxide Na x MO2 (M: transition metal) is a promising cathode material for sodium-ion secondary battery. Crystal structure of O3- and P2-type Na x MO2 with various M against temperature (T) was systematically investigated by synchrotron x-ray diffraction mainly focusing on the T-dependences of a- and c-axis lattice constants (a and c) and z coordinate (z) of oxygen. Using a hard-sphere model with minimum Madelung energy, we confirmed that c/a and z values in O3-type Na x MO2 were reproduced. We further evaluated the thermal expansion coefficients (α a and α c ) along a- and c-axis at 300 K. The anisotropy of the thermal expansion was quantitatively reproduced without adjustable parameters for O3-type Na x MO2. Deviations of z from the model for P2-type Na x MO2 are ascribed to Na vacancies characteristic to the structure

Carrier formation dynamics of a small-molecular organic photovoltaic

We investigated carrier formation dynamics in a small-molecular bulk heterojunction solar cell, 2,5-di-(2-ethylhexyl)-3,6-bis-(5″-n-hexy-[2,2′,5′,2″]terthiophen-5-yl)-pyrrolo[3,4-c]pyrrolo-1,4-dione/[6,6]-phenyl C71-butyric acid methyl ester, with low bandgap (Egap ≈ 1.5 eV). The photoinduced absorption (PIA) spectra of the blend film were decomposed into three PIAs, i.e., those due to donor exciton (D*), acceptor exciton (A*), and mobile carrier (D+). The analysis revealed carrier conversion from D* with a conversion time of ∼1.3 ps

FORMAL PROJECT MANAGEMENT ADOPTION READINESS OF EMERGING CONSTRUCTION FIRMS IN SOUTH AFRICA:

Published ThesisThe drive towards Broad-based Black Economic Empowerment in this industry has been marred by evidence of poor quality construction, delays in project execution and completion leading to cost overruns and general public dissatisfaction with Emerging Construction Firms’ (ECFs’) structures. Since some of these challenges are attributed directly to poor project management practices and dearth of project management skills by most ECFs, there is scope to examine the interface between construction entrepreneurship and adoption of project management practices/techniques mindful of the ECFs’ involvement in government’s construction programmes and projects. It is against this background that the current study explored the formal project management adoption readiness of ECFs in Mangaung Metropolitan Municipality. The thesis statement of this study is that since organisational culture, organisational structure and project management skills constitute the foundation for successful project management, any effective model on project management readiness of ECFs should strongly dovetail with their business strategy as well as these organisational variables. Drawing on a survey design, data were collected from 334 ECFs graded at category 1 to 5 by the Construction Industry Development Board (CIDB) in the Mangaung Metropolitan Municipality of the Free State province of South Africa. The key findings from the empirical study are: Although majority of the ECFs surveyed have high levels of qualification in general education, only a few actually have high level of project management qualification. Majority of the ECFs surveyed also consider project management skills core skills in undertaking projects in order to achieve successful project outcomes. The current organisational culture and structure of the ECFs surveyed largely support the adoption and implementation of project management techniques and tools. The study recommends project management, construction and business education training for ECFs. In addition, the study recommends research into actual project management adoption of ECFs as this study was only limited to exploring adoption readiness

Emotional Involvement Matters: An Analysis of Parenting Patterns and Academic Outcomes of High School Students in 1980, 1990, and 2002

This dissertation addresses the relationship between parental practices and educational and developmental outcomes of high school students in 1980, 1990 and 2002 to explore these three questions: (1) if social capital at home is the key characteristic of parental involvement in education; and (2) if the historical shifts between 1980 and 2002 affected the way in which parents are involved in their children's education. The datasets used for this study were: High School and Beyond (HBS), National Education Longitudinal Study (NELS), and Educational Longitudinal Study (ELS). Early theory and research focused mainly on the transformation and activation of cultural capital through parental involvement in education. It was found that students from middle- and higher-income families have the advantage of receiving higher levels of parental involvement than their peers from low-income families. However, recent research reports that students from high-income families experience severe levels of emotional distress and behavioral problems even if they do well at school. A large body of psychological research also indicates that the parental marital status and the quality of time with parents can influence children's behavioral and emotional outcomes. Consequently, the historical shifts between 1980 and 2002 in mothers' occupational status, gender roles, and family composition can indicate how parenting practices and good relationships between parents and children influence educational and developmental outcomes of high school students. Previous studies ignored three other important dimensions of parenting practices: emotional involvement, autonomy support, and structure. This study examined this relationship using parenting dimensions to determine how cultural capital and social capital within the family interact to indicate educational outcome, high school graduation or Grade Point Average (GPA), positive attitudes toward school, and behavioral problems of lower-class and upper-middle-class students. The results showed that parental emotional involvement is the significant indicator of increased levels of positive attitudes toward school, which was the key characteristic that was associated with high GPAs and high school completion. This finding was consistent across the three different time periods. It suggests the importance of well-established relationships between parents and children, that is, strong social capital between the two agents, which indicate a good consistency with Coleman's (1989) social capital theory. These relationships at home can be at risk when students have mothers with professional careers who work for long hours and live in households with marital disruptions or a single parent, all of which tend to decrease the quality and quantity of time spent together

An Acoustic Study of the Japanese Short and Long Vowel Distinction

Abstract The present study concerns the vowel length distinction between Japanese short and long vowels. Previous studies (Han 1962, Hirata 2004, Kozasa 2005) concluded that short and long vowels differ from each other in terms of duration and pitch fall; that is, long vowels are about 2.4 times longer than short vowels, and long vowels have a pitch fall within a word while short vowels do not. Most studies confirmed the differences between short and long vowels when they are accented. However, none of the previous studies has investigated the differences between short and long vowels using the same test words when a vowel is unaccented; that is, when a pitch fall is absent. The present study concerned the environment where there is no pitch fall within the target vowel: the compound noun context; where HL pitch accent becomes HH, and H becomes L. An acoustic study was conducted in order to investigate the difference between short and long vowels in Japanese in two different contexts, the accented context, and the unaccented context, in which the target word is compounded with the suffix [jo:] in order to neutralize the pitch accent High (H) to Low (L) and HL to LL. The target vowels in the accented context are labeled H for short and HL for long vowels, and the ones in the unaccented context are labeled L for short and LL for long vowels. A wordlist reading task was used for the production study. Measurements were made for pitch onset (F0 value at onset of target vowel), pitch offset (F0 value at offset of target vowel), pitch fall (onset- offset), vowel duration, F1, F2, F3. Analyses showed that F0 neutralization in the unaccented context was incomplete as measured by F0 onset and F0 offset. However, pitch neutralization from H to L as measured by pitch fall was observed. In addition, long vowels were longer than short vowels, and longer in the unaccented context than in the accented context. Pitch fall was significantly larger in the accented context and statistically nonexistent in the unaccented context. Although accented vowels were significantly longer than unaccented vowels, the ratio of short and long vowels was 1:2.4 and 1:3.2 in accented and unaccented contexts, respectively. The difference between short and long vowels was larger in the unaccented context. In terms of vowel quality, F1, F2 and F3 all three significantly differed between short and long vowels in both the accented and unaccented contexts. F1 was significantly higher in the accented context than in the unaccented context and the difference between short and long vowels was significantly larger in the unaccented context. F2 was significantly lower in the accented context than in the unaccented context and the difference between short and long vowels was significantly larger in the unaccented context. The F3 difference between short and long vowels was significant in both accented and unaccented contexts. This difference, however, was larger in the accented than the unaccented context unlike F1 and F2. When vowels were unaccented, the speakers showed larger differences between short and long vowels in F1 and F2, presumably due to the lack of pitch fall

Developing a project management framework for supporting the sustainability of emerging contractors in the Free State

Thesis (PhD Management Sciences (Project management))--Central University of TechnologyThe purpose of this study was to develop a project management framework that could be used to support the sustainability of emerging contractors in the Free State. Emerging contractors are a key vehicle within the construction industry used by the African National Congress Government to redress the economic marginalisation of previously disadvantaged population groups during the apartheid era. While not sparing resources and policy to assist emerging contractors’ businesses to survive and grow, government efforts do not seem to be yielding the desired results as the sustainability of emerging contractors remains threatened by early and high business failure rates. A major concern is that emerging contractors continue to deliver projects in the construction industry that do not conform to cost, time, scope and quality specifications which are considered generally to be the key measures of project success. Therefore, this shortfall places the sustainability of emerging contractors in question since their inability to deliver successful projects hampers their chances of obtaining further business in the construction industry. Moreover, the construction business by nature is project based and, therefore, requires the use of a project management approach. However, it is often reported that emerging contractors lack knowledge and skills in project management and construction and are thus not using a project management approach in their construction businesses which are constrained further by the limited resources available to emerging contractors. Drawing on pragmatism, an explanatory, sequential, mixed-methods research design was adopted for the study. The quantitative data were analysed statistically, while the qualitative data were transcribed and analysed thematically. In the study, the key components required to develop a project management framework that would be useful for emerging contractors in establishing the sustainability of their construction businesses were identified and emphasised. The findings of the study showed that the project management framework developed could support the sustainability of emerging contractors. The findings showed further that there was a statistically significant relationship between components of the project framework (i.e., project lifecycle, project control cycle, tools, and templates) measured and the components of sustainability (i.e. social, economic, and environmental). It was discovered that the project management framework included sufficient elements to prompt some change in how emerging contractors use project management processes in the construction industry. It is recommended in the study that emerging contractors adopt and use the developed project management framework to ensure their sustainability in the construction industry

ELECTRICAL OVERCURRENT PROTECTION GRADING IN V4D

Selective Coordination contributes to the localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the choice of overcurrent protective devices and their ratings and settings. Selective Coordination is critical for the reliability of electrical distribution system and must be analyzed and test regularly. A properly engineered and installed system will allow only the nearest upstream overcurrent protective device to open for both overload and all types of short-circuits, leaving the remainder of the systems undisturbed and preserving continuity of service. The aim of this study is to perform a Coordination and Overload study for the electrical installation in Village-4D T1, in order to know the root causes of the continuous tripping of its main Circuit Breaker which results in frequent power outage in the area. The revision of past researches was the first step taken toward understanding the concept involving protections; followed by a series of site inspections which helped gather the relevant data needed for the study such as the types of protective devices and their arrangement as well as the ratings. The methodology required a sensitivity analysis of the CBs in the area of study and Overload study in which fault levels were simulated using Simulink/MATLAB. The preliminary results of the study based on CBs level of sensitivity showed that V4D protective devices level of sensitivity is medium, therefore less prone to nuisance tripping outside the nominal tripping current. Thus sensitivity is not the factor causing the breaker to trip. However the results from the overload study show that the increasing number of overheating appliances used by students causes the circuit to overload, thus tripping the main breaker

Development of Manually Operated Orange Peeling Device for Domestic Use

Orange a very rich source of vitamin C is a perishable fruit that can only be stored unpreserved for few days before its biological degeneration. When processed to juice, the chemical preservatives that are usually added coupled with the contaminations by its back skin fluid instantly change its natural flavor. This has made many consumers to still prefer freshly peeled fruit to its processed juice. As a solution to laborious hand peeling process that is highly prone to injury due to the sharp tools used several devices have been developed for its peeling. Each of these has its own technical, economic and other shortcomings. This work designed and fabricated a manual orange peeling device with a capability of processing oranges for a domestic family household. The device incorporated a rotary handle through which power was introduced into the system, power screw, spur gear train mounted on a base and cutting blade that performed the peeling function. The fabricated device was operated and assessed to have a peeling efficiency of 97%, generated 2.6% over peeled and damaged oranges and a capacity to peel about 140 oranges per hour as compared to hand peeling that can produce 32 peeled oranges per hour. It is robust, simple to operate and maintain, had good aesthetics and light weight of 619g due to transparent light but strong plastics used to construct the frame and base. Keywords: Orange, peeling, device, household, juice

Developing Institutions and Inter-Organizational Synergies through Digitalization and Youth Engagement in African Agriculture: The Case of “Africa Goes Digital”

As digitalization increasingly gains attention in the agriculture sector, many African youths are seizing the opportunity provided by digital technologies to engage in agriculture. While prior studies have started examining the intricacies of digitalization in agriculture, they have paid less attention to its implications for fostering institutions and inter-organizational synergies that can support and sustain the businesses of youth enterprises engaging with Africa’s agriculture. Against this backdrop, we undertook a qualitative case study to shed light on the development of a community of practice comprising youth enterprises engaging in agriculture through digitalization. Thus, we studied Africa Goes Digital (AFGD), a consortium of young African enterprises that rely on digital technologies and solutions to provide services to farmers across the African continent. The results showed that: (1) the Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA) played a pioneering role as a development agency in supporting enterprises with drones and training for agriculture, which led to the formation of AFGD; (2) two prevalent themes characterized the services offered by AFGD members; (3) AFGD brings members under one platform where they leverage WhatsApp for communication and knowledge sharing and Twitter to showcase success stories and form partnerships with each other to execute certain development projects with governments and development agencies; (4) the lack of regulations or the restrictive regulations on the use of drones are still problems that some members face, and the high costs of sensors and related drones are challenges for the members. Building on the results, we discuss the implications of digitalization for supporting African governments in meeting sustainability goals and conclude by describing the theoretical contribution of our study and promising future research directions