1,022 research outputs found
Recent Evidence on Farm Size and Land Productivity: Implications for Public Policy
Agricultural productivity is low in most of the developing countries including Pakistan. Moreover, slow and meandering agricultural growth is unable to keep pace with the fast and persistently growing population pressure in these countries. That in turn, has, continued to result in malnutrition and recurrent famines [Cornia (1985)]. Worse than this are the results of an ILO (1977) study, which has shown that food consumption inequalities have actually increased overtime not only in the food deficit countries but also in countries experiencing rapid agricultural growth. This points to the ever-hanging shadows of food deficiency and resulting malnutrition over the countries characterised by slow or negative growth in per capita food production and perverted income distribution [Cornia (1985)]. The only choice with these countries is to enhance food production and provide better access to food consumption for the poor masses. In order to achieve this objective policy-makers consider various options including increased use of modern inputs—mechanical and biological technologies, and removal or reform of the prevalent socio-economic power structure in agriculture that is considered to be an impediment to growth. It may not be desirable to apply these options separately in order to achieve the objective of reducing rural poverty [Cornia (1985)]. Growth in agriculture—that is sustainable and appropriate, is possible when all factors of production are accessible to all strata of the farming community. This is particularly so in the case of access to land. In this regard, land redistribution accompanied by increased input supply is the preferred policy option.
STUDY OF STUDENTS’ APPLICATION ABILITY OF PHYSICS CONCEPTS IN THE CONTEXT OF INFLUENCING FACTORS
Secondary school students finds science contents as an organized body of knowledge. They mostly memorize the facts, laws, principles and concepts and recall it in examination. This study is aimed to assess the extent to which the secondary school science students can apply physics concepts in problem situations, everyday life and natural phenomenans. Influencing factors such as home facilities, parent’s education, occupation, and family demographic variables of the secondary school science students were also investigated through a Questionnaire survey. Relationship was explored between the physics concept application abilities of the secondary school science students and the influencing factors. The students’ application abilities of physics concepts measured on concept application ability test were found as 33 %, a significantly low performance. The private sector secondary school science students performed remarkably better than the public sector students and no significant differences were found between the performance of boys and girls students of the same level among both the sectors. Comparatively, the private sector students and girl students in both sectors were found in better position with respect to their home facilities, parental support, education and occupation and some other demographic variables. Positive causal relationship was explored between students’ physics concept application abilities in terms of scores on concept application ability test and the mentioned influencing factors
Multiphysics modelling of PEM fuel cells - with reacting transport phenomena at micro and macroscales
This thesis presents numerical simulations of reacting transport phenomena in polymer electrolyte membrane (PEM) fuel cells. Broadly, the presented work is subdivided into macro and microscale simulations. In macroscale simulations, a unit PEM fuel cell with interdigitated flow field configurations is simulated keeping in mind all the essential transport mechanisms, i.e., transport of species, ions, electrons, heat and liquid water. Additionally, the impact of different material properties is also incorporated in the work such as anisotropy of species, electrons, temperature and liquid water diffusion in the gas diffusion layers. Furthermore, to increase the accuracy of predicted results, more stringent correlations have been applied for the correction of material phases in the catalyst layer for calculating the ion transport. For simulating the electrochemical reactions in the catalyst layers, an advanced agglomerate model has also been used that takes into account the morphological details of the materials present in the catalyst layers. Since, the liquid water transport in the gas diffusion layer represents one of the most critical phenomenons, a validated approach has been utilized instead of the conventional Leverett approach which has been the most common technique used so far in numerical simulations. The simulations with all the stated mechanism have revealed that the current densities predicted by earlier models were always overestimated and the limiting current density is found to be approximately 1.0 A/cm2, while in present work, the limiting current density is about 0.68 A/cm2. The second part of the thesis is dedicated to the generation and simulations of a section of the catalyst layer at microscales. The catalyst layer in PEM fuel cells consists of four different types of material each with a special function to serve. The main theme of work at this section is to segregate each material so that the behavior of each component can be explicitly studied and its response to various physical processes can be noted when subjected to operation. It is observed in simulations at such scale that the selected part of the catalyst layer is much descriptive than the macroscale simulations where it is much difficult to specify each material phase separately. Additionally, at microscales, the correction factors do not need to be defined explicitly because all the processes are confined to their respective phases. The work presented here is limited to single phase flow only and the solid phase is neglected, i.e., the electric current follows the same path as the ionic current due to the limitations in the computational resources
Adoption of Recommended Varieties: A Farm-level Analysis of Wheat Growers in Irrigated Punjab
This study uses farm level data to analyse the determinants of adoption of recommended wheat varieties in irrigated Punjab, Pakistan. A notable proportion of wheat acreage is sown to non-recommended wheat varieties in the province. These cultivars had either lost (overtime) or did not have resistance against yellow rust. Farm size, education, and size of wheat enterprise on the farm are the important determinants of adoption of recommended wheat varieties while tractor ownership and irrigation source play a positive but insignificant role in the adoption decisions. Age and tenure proved to be less of a constraint towards adoption of the recommended wheat varieties. The likelihood of the adoption of recommended wheat varieties varied among tehsils, with the highest probabilities of adoption in Melsi and Arifwala tehsils of cotton-wheat zones I and II respectively.
Adoption of Recommended Varieties: A Farm level Analysis of Wheat Growers in Irrigated Punjab
This study uses farm level data to analyse the determinants of adoption of recommended wheat varieties in irrigated Punjab, Pakistan. A notable proportion of wheat acreage is sown to non-recommended wheat varieties in the province. These cultivars had either lost (overtime) or did not have resistance against yellow rust. Farm size, education, and size of wheat enterprise on the farm are the important determinants of adoption of recommended wheat varieties while tractor ownership and irrigation source play a positive but insignificant role in the adoption decisions. Age and tenure proved to be less of a constraint towards adoption of the recommended wheat varieties. The likelihood of the adoption of recommended wheat varieties varied among tehsils, with the highest probabilities of adoption in Melsi and Arifwala tehsils of cotton-wheat zones I and II respectively.Adoption; wheat varieties; Punjab; Pakistan
The Reliability of Eyewitness Testimony
As perhaps the single most effective method of proving the elements of a crime, eyewitness testimony has been vital to the trial process for centuries. However, the reliability of eyewitness testimony has recently come into question with the work of organizations such as The Innocence Project, which works to exonerate the wrongfully convicted. This thesis examines previous experiments concerning eyewitness testimony as well as court cases in which eyewitnesses provided vital evidence in order to determine the reliability of eyewitness testimony as well as to determine mitigating or exacerbating factors contributing to a lack of reliability
Solid State Fermentation Of Rice Straw For Production Of Cellulases By Selected Fungi
The production of cellulases from rice straw (RS) by four fungi: Trichoderma harzianum (SCahmT105), Trichoderma spp.(1) (STP101), Trichoderma spp.(3) (STP103) and Phanerochaete chrysosporium was investigated. The microbial treatment using solid state fermentation was conducted in 250 ml Erlenmeyer flasks considering rice straw as a major solid substrate. The highest cellulase activities such as 25.53 U/g of rice straw due to filter paper activity and 42.86 U/g of rice straw due to carboxymethyl cellulose activity were obtained at day 4 of cultivation using Phanerochaete chrysosporium for the purpose of selecting the best fungus among these four strains. Glucosamine for growth and reducing sugar as substrate utilization indicator were observed to evaluate the fermentation of rice straw in the experiment and pH values were recorded as well.
Four process parameters of the solid state fermentation namely moisture content, mineral content, co-substratre and inoculum size with three levels of each parameter were used to optimize the production of cellulases by Plackett-Burman technique under factorial design. The results for first phase of optimization showed that the production of cellulases were higher i.e. 26.43 U/g of rice straw due to filter paper of activity and 46.25 U/g of rice straw due to carboxymethyl cellulose activity compared to the production obtained during the earlier study of selecting best strain among four fungi but the optimum regions of the surfaces was not found. Second phase of optimization was conducted to determine the actual optimum conditions within the ranges of variables tested. The experimental data were used to develop second order polynomial models considering linear, quadratic and interaction effects of the variables (factors). The optimum values obtained at second phase of optimization for moisture content, inoculum size, co-substrate and mineral content were 50% (v/w), 10% (v/w), 1% (w/w) and 5% (v/w) respectively.
Using the final model equations the process factors/variables were tested by increasing or decreasing the values within the ranges of parameters tested and optimum production of cellulases were obtained to be 30.18 U/g of rice straw (FPU) and 53.93 U/g of rice straw (CMCase) for Phanerochaete chrysosporium with the optimum process conditions. A final experiment with these optimum process parameters of SSF was conducted to evaluate the production of cellulases as well as the validation of the models which indicated the production of 29.46 U/g of rice straw due to filter paper activity and 54.83 U/g of rice straw due to carboxymethyl cellulose activity in the laboratory which approved the optimum production obtained with 2.4% and 1.6% error, respectively
Building An Integrated Digital Transformation System Framework: A Design Science Research, The Case Of Feduni
The purpose of this paper is to propose an integrated digital transformation system framework (IDTSF) to help support business leaders and teams in making their products, services, and operations more streamlined and competitive. The framework will help organizations to best meet user/customer needs with minimum waste and time and enables businesses to achieve efficiency compared with island and traditional sequential approaches. The proposed framework can also provide insights to help organizations to avoid common failures when deploying digital transformation initiatives. The paper follows the design science research (DSR) and the information systems design science research (ISDSR) methodologies to develop the IDTSF model and a practical design artifact. The main problems were the initiation, execution, and governance challenges associated with digital transformation. After identifying the problems and the objectives, a relevant IDTSF model was synthesized and tested as a design artifact. The results of the test of the proposed artifact showed its effectiveness and efficiency in facilitating the components of the model in creating a cohesive framework
The potential of unintended effects in potato glycoalkaloids
Unintended changes have long been considered as byproducts associated with genetic improvement of crop plants. The issue has been hotly debated during recent years following the identification of some unwanted characters in genetically engineered crop plants. In this context, the subject of unintended effects of plant transformation on known toxic compounds has been an area of immense interest. Compositional changes in these toxins may have a profound impact on human and animal health. Potato glycoalkaloids are known toxic compounds to humans and animals. These days, food safety evaluation tests of transgenic potato varieties are conducted on routine basis to keep the glycoalkaloid levels below a threshold level. Some transgenic potato varieties have been found with altered glycoalkaloid levels, which have created doubts on the process of transformation and tissue culture conditions. In this review, we summarize recent work on unintended effects in crop plants with special emphasis on compositional changes in potato glycoalkaloids as a result of genetic transformation.Keywords: Unintended effects, transgenic potato, glycoalkaloids, food safety, environmental stressAfrican Journal of Biotechnology Vol. 12(8), pp. 754-76
An Extensive Review on Spectral Imaging in Biometric Systems: Challenges and Advancements
Spectral imaging has recently gained traction for face recognition in
biometric systems. We investigate the merits of spectral imaging for face
recognition and the current challenges that hamper the widespread deployment of
spectral sensors for face recognition. The reliability of conventional face
recognition systems operating in the visible range is compromised by
illumination changes, pose variations and spoof attacks. Recent works have
reaped the benefits of spectral imaging to counter these limitations in
surveillance activities (defence, airport security checks, etc.). However, the
implementation of this technology for biometrics, is still in its infancy due
to multiple reasons. We present an overview of the existing work in the domain
of spectral imaging for face recognition, different types of modalities and
their assessment, availability of public databases for sake of reproducible
research as well as evaluation of algorithms, and recent advancements in the
field, such as, the use of deep learning-based methods for recognizing faces
from spectral images
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