1,583 research outputs found
Mixed farming systems in sub-Saharan Africa
The important position and role of mixed farming systems in land use intensification in subSaharan Africa is reviewed. This is done by examining the current situation that is followed with a justification for mixed farming. Further sections follow on changing patterns of land use, including the effects of tsetse flies and trypanosomiasis, and on constraints to further crop-livestock integration. Research needs are considered in a final section with particular emphasis on biophysical factors (feed development, nutrient management, dualpurpose livestock, animal health, genetic improvement and natural resource management) and policy analysis
The ecology, vegetation and land use of subhumid Nigeria
Describes the geology, relief, climate, major soil types, vegetation zones and land use patterns of the subhumid zone of Nigeria. Presents results of studies on natural forage productivity & composition and forage production constraints
Integration of forage legumes into the cropping systems of Nigeria's subhumid zone
Summarizes research in crop-forage combinations in subhumid Nigeria w. an aim of developing an integrated pasture-livestock-crop system suitable to accommodate & improve both crop & livestock production
Analyzing the performance variation between competitive and non-competitive examinations among grade 5 students
The main objective of this research study is to test whether there is any
performance variation exists in between the grade 5 students' performances in
competitive and non-competitive examination. The grade S scholarship examination is a
competitive conducted by the government and school term examinations (2n d and 3r d
terms) are non-competitive. Most importantly, this is to examine the impact of the grade
5 scholarship examination in the development of child education which is an analysis
about how far the stress makes poor performance among grade 5 students.
Two types of data were collected to test this object; firstly the grade 5 scholarship
examination marks of the students for the past consequent 10 years (2000-2009).
Secondly the same students' 2 n d and 3 r d terms school examination marks for the same 10
years.
To analyze these data ANOVA statistical procedure was used to. test the
association between the students performance between competitive and non-competitive
examinations. Turkey's student zed range method was used for multiple comparison of
means between scholarship and school terms examination. Since the competitive
examination takes place in between 2n d and 3r d term examinations. Further another
comparison test was made to analyze the association in between 2n d and 3r d term
examinations. These comparisons were used in order to check whether there is any
improvement in the students' performance after the scholarship examination.
The results showed that students' performances are significantly poor in the scholarship
examination comparing with school terms examination in all 10 years and there is no
significant difference between the students' performances in 2D d and 3r d terms
examination
Synthesis and Characterization of Kesterite Cu2ZnSnS4 (CZTS) Thin Films for Solar Cell Application
The quaternary compound Cu2ZnSnS4 (CZTS) gained considerable attention in the last decade due to its potential as an active-layer semiconductor for low-cost thin-film solar cells. The material is composed of nontoxic and Earth-abundant constituents, has optical properties suitable for photovoltaic application, and can be synthesized using a wide variety of methods.
Polycrystalline CZTS was grown in this work using vacuum-based deposition to first deposit metal films (precursors) of Cu, Zn, and Sn. In a subsequent step, the precursors underwent an annealing treatment in sulfur vapor environment (sulfurization) to form CZTS. Using sputtering, a physical vapor deposition (PVD) technique, two different kinds of metal precursors were deposited: a) stacked precursors, in which a stack of metal layers are sequentially deposited on a glass substrate, and b) co-sputtered precursors, in which the three metals are deposited simultaneously.
The effect of sulfurization time and temperature was investigated to optimize the process and to study the impact of both factors on the morphological and structural properties of the synthesized compound. CZTS films based on a stacked precursor were prepared and characterized by X-ray fluorescence, energy-dispersive X-ray spectroscopy, electron probe microanalysis, X-ray diffraction, scanning electron microscopy , ultraviolet-visible-near-infrared spectrophotometry, and Auger electron spectroscopy. Films with dense morphology, good crystallinity, and optical energy bandgap close to 1.5 eV were obtained using annealing temperatures of 500 °C and 550 °C. Furthermore, the study addressed the issue with Cu2-xS phases segregated on the film surface and suggested a route to avoid their evolution.
The secondary-phase dependence on the chemical composition was studied, focusing on suppressing Cu2-xS phases. In addition, we addressed the importance of Sn/Cu ratio as a controlling factor to avoid developing these detrimental phases. An electron backscatter diffraction study confirmed the role of increased Cu content in achieving larger grains.
Studying the influence of the stack sequence in the precursor revealed that depositing Zn as the first or second layer leads to better adhesion, and depositing Cu as top layer minimizes the loss of Sn and allows better control of film composition. Solar cells based on CZTS films prepared with the sulfurization of precursors with different stacking orders were produced, and the best device showed power conversion efficiency (PCE) of 4.43%.
CZTS films based on co-sputtered precursors showed very promising results in terms of large grains, dense morphology, and smooth surface; however, they suffered from poor adhesion to the Mo layer due to compressive intrinsic stresses. Further investigation is needed to identify the stress origin and improve the contact to the back electrode. The best device based on CZTS films from co-sputtered precursors yielded a PCE of 1.72%
The establishment and management of fodder banks
Presents guidelines for the establishment & management of fodder banks, particularly selection of site, land preparation; sowing & presowing treatment of legumes, seedling establishment and early management. Lists 5 of the factors influencing productivity of fodder banks in the subhumid zone of Nigeria and includes preliminary results of productivity crude protein content, botanical composition and regenerative ability
The mystical doctrine of Abū-Ṭālib al-Makkī as found in his book Qūt al-qulūb
The purpose of this study is to examine the life
and works of Abu-Talib al-Makkx, one of the greatest
sufi writers of the fourth Islamic century, with special
attention being paid to his mystical doctrine, as
expounded in his chief work entitled "Qut al-Qulub fx
mu'amalat al-mahbtib" .The thesis is divided into two parts. The first part,
which constitutes the first chapter, deals with the
biography of al-Makkx and examines the characteristic
traits of his thoughts and personality.In the second part, which constitutes four chapters,
the mystical doctrine of al-Makkx is studied under the
broad based divisions of: The religious life (ch. Ii),
the mystical doctrine (ch. Ill), the mystical life (ch. IV),
the mystic path (ch. V).In analysing al-Makkx's mystical doctrine, detailed
studies are made in relation to his concept of religious
life as a preliminary basis for the higher mystical life,
and his concept of mystical life with special reference to
his concept of the heart, science of the heart, theory of
knowledge, gnosis, and finally his concept of the
mystical states and stations.This thesis shows the contribution made by al-Makkx,
to the formulation of sufi theory and practice, during the
most significant period of sufism, namely the period of
formulation, systematisation, and documentation
Democratisation and good governance in Sri Lanka: a case study of eastern province
In 2008, provincial council elections were held in the Eastern Province
amid high hopes that they would bring about positive change for Eastern people who
have suffered long periods of conflict, weak governance and poverty. The prime
objective of this study is to critically analysis the democratization and good governance
process in the Eastern Province. Further this research endowers to identify the
challenges which are faced by democratic institutions in the East Sri Lanka. This study is
critical nature in which has been used primary and secondary data. The primary data has
been collected through question ire, key informants interviews and focus group
discussion. Three persons have been interviewed as key informants and three focuses
groups have been discussed. The Secondary data has been collected from books, official
documents, reports, journals and news paper articles. The major findings of this study is
that the faith in the democratic process among ordinary people has begun to wane and
government support to democratisation processes has tended to focus most heavily on
the central government levels, rather than on building the relationship between the
eastern people and the local leaders they come into the most day-to-day contact with
(whether they are democratically elected or not). Further, in the absence of well
functioning state institutions at the local level, other mechanisms of holding leaders to
account have evolved that have so far not been impacted by democratisation
Al Jazeera Arabic and Al Jazeera English Websites: Agenda-Setting as a Means to Comparatively Analyze Online News Stories
This study seeks to investigate similarities or differences in the content of news stories published on Al Jazeera Arabic (AJA) and Al Jazeera English (AJE) websites. Guided by agenda-setting theory 2,400 online news stories were analyzed. Findings indicate that on fewer than 8% of the time do AJA and AJE display the same news story on their websites. Since Al Jazeera’s target audience differs depending on the language, the study argues that AJA and AJE set the agenda for two sets of news consumers. This is fairly significant as Al Jazeera seeks to play a greater role in news dissemination to a global audience. Al Jazeera deliberately seeks to highlight a certain news item, such as the almost daily coverage of the crisis between Qatar and four other Arab countries in the summer of 2017, thereby actively engaging in agenda-setting. Findings also indicate that AJA publishes more news stories pertaining to the Arab world than AJE. AJA’s coverage of the African and South American continents is relatively low compared to the Arab region, thereby directing audience’s attention to events and issues closer to Al Jazeera’s home base of Qatar. The study also argues that news consumers play a significant role in determining the news items displayed by news outlets
Progression of phenotype in Leber's congenital amaurosis with a mutation at the LCA5 locus
BACKGROUND: Leber’s congenital amaurosis (LCA) accounts for 5% of inherited retinal disease and is
usually inherited as an autosomal recessive trait. Genetic and clinical heterogeneity exist. Mutations
have been described in the RPE65, CRB1, RPGRIP1, AIPL1, GUCY2D, and CRX genes and other pedigrees
show linkage to the LCA3 and LCA5 loci. The latter is a new locus which maps to 6q11-q16. The
ocular findings and the evolution of the macula staphyloma are described in five members of a Pakistani
family with consanguinity and a mutation in the LCA5 gene.
METHODS: 13 family members including five affected individuals consented to DNA analysis and ocular
examination including fundal photography.
RESULTS: Ocular abnormalities are described. The most striking feature was the progression of macula
abnormalities in three brothers resulting in a colobomatous appearance in the eldest compared to only
mild atrophy in the youngest. The phenotypic pattern of this mutation in this Pakistani family contrasts
with the “Old Order River Brethren” who were of Swiss descent, in whom the mutation was first
described.
CONCLUSION: The evolution of a new phenotypic picture is presented to a mutation in LCA5
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