Performance of jatropha oil blends in a diesel engine

Results are presented on tests on a single-cylinder direct-injection engine operating on diesel fuel, jatropha oil, and blends of diesel and jatropha oil in proportions of 97.4%/2.6%; 80%/20%; and 50%/50% by volume. The results covered a range of operating loads on the engine. Values are given for the chemical and physical properties of the fuels, brake specific fuel consumption, brake power, brake thermal efficiency, engine torque, and the concentrations of carbon monoxide, carbon dioxide and oxygen in the exhaust gases. Carbon dioxide emissions were similar for all fuels, the 97.4% diesel/2.6% jatropha fuel blend was observed to be the lower net contributor to the atmospheric level. The trend of carbon monoxide emissions was similar for the fuels but diesel fuel showed slightly lower emissions to the atmosphere. The test showed that jatropha oil could be conveniently used as a diesel substitute in a diesel engine. The test further showed increases in brake thermal efficiency, brake power and reduction of specific fuel consumption for jatropha oil and its blends with diesel generally, but the most significant conclusion from the study is that the 97.4% diesel/2.6% jatropha fuel blend produced maximum values of the brake power and brake thermal efficiency as well as minimum values of the specific fuel consumption. The 97.4%/2.6% fuel blend yielded the highest cetane number and even better engine performance than the diesel fuel suggesting that jatropha oil can be used as an ignition-accelerator additive for diesel fuel.     

Gate quality ultrathin (2.5 nm) PECVD deposited oxynitride andnitrided oxide dielectrics

Ultrathin oxynitride using plasma assisted deposition was evaluated against thermal oxide and nitrided thermal oxide as an alternative direct tunneling gate dielectric to thermal oxide in the 2.5-nm regime. The oxynitride showed an enhanced high field effective mobility relative to the thermal oxide although the low field mobility was slightly depressed. The N₂O nitrided oxide showed an enhanced high field effective mobility with no degradation in low field mobility. The interface state density of the oxynitride was equivalent to that of the thermal and nitrided thermal oxides; a very welcome observation for this deposition chemistry and anneal conditions     

Comparative physical and electrical metrology of ultrathin oxidesin the 6 to 1.5 nm regime

In this work, five methods for measuring the thickness of ultra-thin gate oxide layers in MOS structures were compared experimentally on n⁺ poly-SiO₂-p-Si structures. Three methods are based on electrical capacitance-voltage (C-V) and current-voltage (I-V) data and the other two methods are HRTEM and optical measurement. MOS capacitors with oxide thickness in the range 17-55 Å have been used in this study. We found that thickness extracted using QM C-V and HRTEM agree within 1.0 Å over the whole thickness range when a dielectric constant of 3.9 was used. Comparison between thickness extracted using quantum interference (QI) I-V technique and optical measurement were also within 1.0 Å for thickness 31-47 Å. However, optical oxide thickness was consistently lower than the TEM thickness by about 2 Å over the thickness range under consideration. Both optical measurement and QM C-V modeling yield the same thickness as the nominal oxide thickness increases (>50 Å)     

Analytic model of parasitic capacitance attenuation in CMOS deviceswith hyperthin oxides

The parasitic accumulation capacitance attenuation in MOS structures with hyper-thin oxides has been modelled using a distributed RC network. The simple analytic model is in excellent agreement with a two-dimensional numerical simulation and experimental data     

The quality assessment of gari produced by using microwave energy

Summary A novel technique using microwave energy for roasting and drying or garification of fermented cassava mash is investigated. The quality of gari produced using this method compared favourably with the standards quoted in the literature and with those of commercial gari purchased from a London market, in terms of colour, swelling capacity, moisture, pH and total acidity.     

Optimizing agbelima production: varietal and fermentation effect on product quality

The variety of cassava used for processing has been shown to influence the physico-chemical, functional and other quality characteristics of some cassava products. Thus, the effects of varietal differences and fermentation time on some quality indices of agbelima, a fermented cassava product, was investigated with the objective of optimizing production. Three improved cassava varieties, TMS 4(2)1425, TMS 50395, TMS 30572 and two local varieties, Bosomensia and Biafra were investigated at fermentation times of 0, 24, 48 and 72 h. Quality parameters assessed included total titratable acidity, pH, textural properties and colour characteristics. All the parameters were significantly (P 0.01) affected by both varietal differences and fermentation time. The interaction between varietal difference and fermentation time were also highly significant (P 0.01) for all the parameters assessed. The results of this study show that the selection of cassava varieties for processing and the duration for fermentation are critical to the quality of the final agbelima product.     

Processing methods and microbial assessment of pito (an African indigenous beer), at selected production sites in Ghana

Pito is an indigenous sorghum beer brewed on household basis with variation in product quality. The brewery processes for assuring the quality of the drink have not been clearly defined. To evaluate the brewery processes at 12 selected brewery sites in Ghana, the study adopted oral interviews/survey, observations and laboratory tests that sought to identify differences in processing methods and how they influence the quality of the drink. Pito samples were taken from selected centres at dominant producing areas: the Upper West Region (Nandom), the Northern Region (Tamale) and Ashanti Region (Kumasi). The samples were tested for aflatoxins and coliform levels, and the yeasts and moulds species present were identified. The survey results revealed that there were five similar but sequentially different processing methods currently being used to brew the drink in the selected regions. Pito samples from Kumasi had the highest mould contamination of 3.7 × 10³. The moulds identified in the beverage were Aspergillus clavatus, Mucor hiemalis, Cladosporium sphaerospemum and Cladosporium herbarum. The yeasts identified were Saccharomyces cerevisiae, Debaryomyces hansenii and Pichia anomala. Aflatoxin was absent in all of the beverage samples, although the malted grain sample from the Tech‐Junction in Kumasi showed an aflatoxin concentration of 9.58 ppb. Coliform tests were negative for all of the samples. The study, emphasizes the need for a more controlled and standard method of production to improve on the quality of the drink and to ensure the safety of its consumers. Copyright © 2016 The Institute of Brewing & Distilling     

Effect of aspirin in coronary artery bypass grafting

OBJECTIVES: To evaluate the effect of aspirin (ASA) therapy on postoperative blood loss, transfusion requirements, reoperation for bleeding, duration of stay in the intensive care unit and in the hospital in a selected population undergoing a first coronary artery bypass grafting (CABG) surgery. DESIGN: Prospective observational study in consecutive patients during a 3-month period. SETTING: A teaching cardiothoracic center. PARTICIPANTS: Two hundred forty consecutive patients undergoing elective coronary artery bypass grafting surgery for the first time. INTERVENTIONS: Two hundred forty consecutive patients admitted for a first CABG the day before surgery were visited. patients with an abnormal routine coagulation screen or taking drugs that might have affected their coagulation mechanisms were prospectively excluded (n = 96). The date of the last dose of ASA was recorded in the 144 remaining patients, and data were acquired prospectively. MEASUREMENTS AND MAIN RESULTS: Total mediastinal blood drainage, blood products usage, reopening, and duration of intensive care unit and hospital stay were recorded. Patients were grouped by days free of ASA. There were no significant differences detected between groups. CONCLUSIONS: In patients undergoing a first CABG and with no known factors affecting their coagulation, ASA therapy did not appear to increase blood loss, reopening for bleeding, or blood products usage requirements during the hospital stay. ASA therapy did not influence the duration of stay in intensive care or in the hospital.