Papers by Keyword: Yield

Abstract: Using disposable masks to protect against coronavirus 19 (COVID-19) has become a habit during the pandemic. However, the emergence of contaminated mask waste causes environmental problems because recycling is difficult. This research carried out the co-pyrolysis of disposable masks waste with sugarcane bagasse in a tubular reactor. The temperature and blend ratio of sugarcane bagasse to disposable mask was varied to investigate the product distribution. The maximum liquid product yield was obtained at 54.3% at 400 °C using a blend ratio of sugarcane bagasse to disposable mask 1/2. Based on the Gas Chromatography Mass Spectrophotometry (GS-MS) analysis, the liquid products consists of alkanes, alkenes, acids, alcohols, ketones, and aromatic compounds.

Abstract: The detection and classification of SiC Epitaxial extended defects was refined to separate out defective areas that influence device characteristics. Die level defect localization along with defect area calculations were performed on millions of die across product groups. A clear impact of non-killer defects was observed, especially with increasing density and defective area in the die. Specifically, all types of stacking faults caused higher leakage, lower blocking voltage, and increases in ON resistance and threshold leakage. Furthermore, MOSFET devices were affected to a much larger extent than diode devices. Testing die with higher numbers of defects provides insight on device reliability. Analyzing devices with specific counts of BPDs let us quantify the amount of bipolar degradation caused drift by product/voltage classes.

Abstract: Agricultural mechanization is an essential factor influencing agricultural output and the profitability of farming activities. The influence of agricultural mechanization on agricultural production in Lagos State, where the majority of the farmers use modern technologies for their farming operations, was investigated. The investigative research approach method was employed to retrieve information from farmers through a structured questionnaire. A five rating scale questionnaire was utilized for the respondents to show their level of agreement or disagreement. The percentage was used to analyze the respondents' bio-data. At the same time, the mean was employed to answer the research questions. The null hypotheses were tested using Chi-square statistics at 0.05 significant levels. The results revealed that agricultural mechanization increased the cultivated land, crop yields, and farmers’ income with cumulative means of 2.34, 1.07, and 1.44, respectively. Socioeconomic characteristics, available technology, and government policies influenced agricultural mechanization with cumulative means of 1.93, 1.24, and 1.79, respectively. The entire six hypotheses were rejected based on the results of the Chi-square statistics with the calculated X² values of 8,989.09, 473.59, 3,977.42, 2,192.63, 226.07 and, 1,878.05; and critical X² values of 46.19, 46.19, 36.42, 31.41, 21.03, and 31.41, for the significant effect on the size of land cultivated, crop yield, farmer’s income, socioeconomic characteristics, available technology, and government policies respectively. The study showed that agricultural mechanization had a significant influence on crop production and farmers’ income. Therefore, there is a need to improve the available technologies and formulate and implement policies to make agricultural mechanization accessible and sustainable.

Abstract: Multi-channel defect detection in epitaxial SiC layers is used to detect and classify various extended defects. The effects of the killer defect category are analyzed on hundreds of production diode and MOSFET wafers. Invariably, the number of these killer defects sets the yield entitlement for each wafer, and electrically, they fall into a few expected failure bins depending on their position on the die. A variety of non-killer defects like Bar Stacking Faults (BSFs), V-type defects, isolated micro-pipe related bumps, stacking faults, scratches and deep pits are identified in over thousand die each, and their effect on fully fabricated diode and MOSFET products are determined at wafer sort. A very high percentage of the die containing these non-killer defects pass all electrical tests including the rigorous Unclamped Inductive Switching (UIS) testing. Specifically, a population of electrically passing die, containing BSFs, are identified and packaged for High Temperature Reverse Bias (HTRB) tests. Every BSF containing die passes both forward and reverse 1000-hour HTRB drift tests.

Abstract: In this study, UV Photoluminescence (UVPL) and Differential Interference Contrast (DIC) mapping was applied for process control of a 1.2 kV 4H-SiC VDMOS fabrication process at different process stages in order to investigate the influence of shallow pits on the electrical behavior of the devices. In particular, it could be shown that UVPL and DIC mapping allows the correlation of shallow pits and the occurrence of darker regions in the UVPL images and distinguishing differently implanted regions at distinct process stages. By comparing the darker regions of the UVPL scan with the electrical blocking characteristics of the associated devices a direct correlation between the occurrence of shallow pits and the reduction of the blocking capability of the devices could be observed.

Abstract: In this research, the hydrodistillation extraction method has been adopted to extract the essential oil from Vietnamese Mandarin (Citrus reticulata Blanco) peel purchased from Thu Duc, Vietnam. Various extraction conditions influencing the oil yield were investigated. The obtained essential oil was evaluated for physicochemical characteristics. GC–MS studied the chemical composition of the oil. The results showed that with the ground Mandarin peel, the ratio of peel to solvent ratio 1:4 (g/mL), extraction time of 150 minutes at a temperature of 110-120°C, the highest essential oil yield was attained at 5%. Bioactive components found at high content included limonene (97.655%), were followed by β-Myrcene (1.395%), 1R-α-Pinene (0.561%), L-β-pinene (0.264%), Sabinene (0.126%).

Abstract: Inline metrology tools are widely used to detect defects in SiC epitaxial layers. The defect statistics are used in a variety of ways to determine quality, pass/fail and screen affected die. In this work, we document the automated detection and classification of various epitaxial defects based on type and origin. We further classify these categories into killer and non-killer defects and compare them to the electrical yield of Schottky Diodes. The origins of these defects are determined in broad categories, resulting in a clustering and yield-scaling model, which agrees very closely to experimental data. Further, we look at on-wafer screening techniques of potential weak die by both defect tagging and unclamped inductive switching (UIS) stress testing. Successful 1000-hr reliability tests show the robustness of our detection and screening methods.

Abstract: Production yield is a major factor for semiconductor device manufacturing. To produce high performance devices cost efficiently, it is important to know the process windows of the implemented production technology. This can influence the yield in different ways. One of the critical steps is the photolithography. In this work the impact of misalignment within the technological limits is analyzed and discussed. 4H-SiC VDMOS Transistors were produced and the electrical characteristics were compared with the overlay accuracy of the devices. Small change in channel length can lead to large impact on the electrical characteristic. Especially when the channel length reaches values near to the critical length for short channel effects (SCEs), small overlay inaccuracies influence the electrical characteristic of the devices in an increasing manner. Different cell designs were analyzed regarding their robustness to misalignment.

Abstract: Pomelo (Citrus grandis .Linn Osbeck) oils is becoming more and more popular for everyone because it has great benefits. However, the efficiency of essential oil extraction process depends on the method and is influenced by a number of factors. Microwave-assisted hydro-distillation and Response Surface Methodology are selected for extracting and optimizing the factors affect the yield of the pomelo oil. The pomelo oil has the optimum yield was 4.5% when extracted with a water and peels ratio of 3,119: 1 (ml/g) for time extraction of 117.336 (minutes) at a microwave power of 403.115 (W) with high reliability (R² = 0.9831)

Abstract: Through yield and Sauter mean diameter, the sucrose crystallization was studied in vibrated bed equipment, in which, supersaturation degree, dimensionless vibration number and crystallization time were independent variables. A central composite design with seventeen trials was performed in order to ascertain the influence of each variable in both responses, the crystallization temperature and the amount of seeds were kept constant. The crystallization vibration system differs from the usual configuration, consisting of two perforated discs made of stainless steel, one loop and three aluminum rings. By canonical analysis, it was obtained the operating condition which maximizes the yield and average crystal size. Surface responses were also obtained according to the relevance of each variable, in which were evidenced the high supersaturation and vibration influence for both factors, the high quadratic term of all variables on the crystal yield, and also highlights the great interaction between supersaturation and the dimensionless vibration number.