Theses & Dissertations
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/1132
2024-03-28T08:05:02ZThe effects of price and non-price factors on maize supply elasticities in Iraq
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/80261
The effects of price and non-price factors on maize supply elasticities in Iraq
Maize is the one of the most important crops in Iraq, being both the major feed grain for livestock and the primary staple food crop for the majority of the Iraq population. Furthermore, the maize industry contributes substantially to employment, manufacturing, foreign exchange and food security. The importance of maize in contributing to national growth is critical; this makes it meaningful to investigate the nature of maize farmers’ production decisions. This study quantifies the supply response of maize farmers to price and non-price factors in Iraq using econometric techniques. The non-price factors considered in this study are land usage, technology, rainfall, production lagged one year and siege. A modified Nerlovian partial adjustment model was applied on historical time series data spanning from 1986-2015 to estimate the supply response of maize in Iraq. To deal with the expected problems associated with time series data the study adopted several diagnostic tests. Results indicate a short-run
supply elasticity and a long-run supply elasticity are inelastic, signifying that maize farmers are less sensitive to price changes. The results confirm that price factors seem to have the same effect on maize supply in Iraq. These findings coincide with
those obtained in supply response studies for field crops conducted in other developing Iraq countries. The study also showed that non-price factors such as, rainfall, production lagged one year, technology and land usage have a positive impact on maize production. Given the findings, the study recommends policies that focus more on non-price factors as a means of stabilising maize production. The study also recommends that Industry stakeholders and policymakers should find means to integrate the significant relationships between non-price factors and production output into future decisions and marketing policies to safeguard a healthy, growing and sustainable maize industry in Iraq.
Master of Science in Economics
Optimization of six-port device for QPSK demodulation in front-end communication receiver
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/80260
Optimization of six-port device for QPSK demodulation in front-end communication receiver
In the Quadrature Phase Shift Keying (QPSK) front-end communication receiver system, a six-port device is the key component for identifying the microwave reflection coefficient of the receiving QPSK signal. The use of a mixer in a conventional QPSK
receiver can be avoided by employing a six-port device in the front end communication receiver. However, the traditional six-port receiver performance is usually poor due to limited operational bandwidth from high amplitude imbalance and high phase
imbalance of its transmission coefficients. Therefore, in this study, a six-port device is optimized for achieving low amplitude and phase imbalance that lead to wideband characteristics of QPSK demodulation in the front-end communication receiver. Since a
six-port device is constituted by a power divider and 3-dB quadrature couplers, the optimization starts by designing both components individually using simulation tools, CST Microwave Studio. The optimization of the power divider is done by employing multi-section techniques on a Wilkinson power divider while rectangular stubs are introduced in a 3-dB quadrature elliptical coupler. By considering the overall Sparameter performances for return loss and isolation to be more than 10 dB and
transmission coefficients to be -3 ± 0.5 dB, the power divider results show that the measured double-stage performs better in a fractional bandwidth of 168.62% across a frequency range 1 – 11.75 GHz compared to a single-stage which only has a percentage of 139.80% within a frequency range of 1.55 – 8.75 GHz. To compare the stubs in the coupler, the results show that good performance is achieved over the entire bandwidth of 3.44 – 8.03 GHz for return loss and isolation of more than 10 dB, transmission coefficients of -3 ± 1.5 dB and a phase difference across Ports 2 and 3 with respect to Port 1 of 90' ± 5'.
Master of Science in Communication Engineering
Characterization of different types of spent mushroom substrate (SMS) for African catfish (Clarias Gariepinus) diet suitability
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/80259
Characterization of different types of spent mushroom substrate (SMS) for African catfish (Clarias Gariepinus) diet suitability
Spent Mushroom substrate (SMS) is one of agricultural wastes produced by thever expending mushroom industries in Malaysia. Chemically, it is rich in organic matter which potentially can be utilized for aquaculture. Utilization of SMS as fish feed has
never been conducted before as very limited information on SMS biochemical composition is available. Regarding to this matter, new formulation of fish feed was developed by incorporating SMS and other ingredients namely soybean waste, fish meal,
topioca flour and rice bran. Commanly, different types of SMS that being cultivated at six to seven cycles were collected which identified as white oyster (Pleuratos ostreatus), grey oyster (Pleuratos sajor-caju), abalone (Pleuratos cystidiosus), ganoderma
(Ganoderma lucidium) and black jelly (Auricularia polytricha). Those SMS were tested on their biochemical composition which involving the analysis of crude protein, carbohydrate, fat, lignin and ash. Overall trend showed an increment in crude protein
and fat content, whereas carbohydrate and lignin showed a reduction in the content. Ganoderma attained the highest protein value, 36.6 g, followed by black jelly, white oyster, grey oyster and abalone. Contradictory, lowest carbohydrate reduction was
observed in ganoderma at 70.42 g and the most was in black jelly. Increment in fat and reduction in lignin showed almost similar value for each SMS. The highest (ganoderma), medium (white oyster) and lowest (abalone) protein content were the basis of SMS types selection to be incorporated in pellet formulation using Pearson square method which emphasized on the protein and energy. The ingredients were mixed and a pelletalization was carried out after 40 minutes of steaming process at 80° C. A series of physical properties test of SMS pellets were conducted to confirm the applicability of the formulated pellet for fish consumption by comparing with commercial fish feed.
Master of Science in Bioprocess Engineering
Feature-based support generation in fused deposition modeling (FDM) machine
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/80258
Feature-based support generation in fused deposition modeling (FDM) machine
Feature-based Support Generation is a technique that has been proposed in Fused Deposition Modeling (FDM) machine. This technique can provide information of volume and amount of support structure which are closely related to orientations of part
deposition. There are two types of support features in FDM part model development, which are Self-Supported Features (SSF) and External-Supported Features (ESF). The SSF requires no support material while ESF involves the use of additional support
material in their fabrication. Currently, various techniques have been suggested to identify features are limited to a specific manufacturing process. In other aspect, the LM process planning is not fully automatic and lead to part quality degradation and increases the possibility of making errors. Furthermore, many errors are occurred due to the involvement of human in this crucial process. Other issue is that the Stereolithography (STL) file format representation is used to transfer the CAD data to the LM process planning resulting to the loss of design and functional feature information. Determining the OPDO was found to be difficult and consumed longer build times that influenced by the speed and the change of nozzle's tip during material deposition. The main objective of this work is to integrate between Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) using a feature-based technique. This will help in automation of FDM process planning prior to the manufacturing of part model with less human error. In this work, the minimum volume and amount of support structure are selected in order to determine the optimum part deposition orientation. This work also focuses on the improvement of the non-contact surface area between the support structure and part model. The accuracy of the network is determined through five MLP structures (Structures 1 to 5). The accuracies for all MLP structures at specific hidden nodes are analysed.
Doctor of Philosophy in Mechatronic Engineering