Influence of fatty acids in waste cooking oil for cleaner biodiesel

Physiochemical properties of biodiesel, a sustainable and green alternative fuel produced from renewable resources, are greatly influenced by the structural features of polyunsaturated, monounsaturated and saturated fatty acids. Two feedstock oils, potentially contribution to cleaner technologies, refined cooking oil and waste cooking oil derived from palm olein have been studied. Fatty acid compositions of the refined cooking oil and waste cooking oil were analysed and confronted with other literature sources. Critical parameters such as cetane number (CN), iodine value, cold filter plugging point (CFPP) and oxidation stability (OS) were correlated with long-chain saturated factor and degree of unsaturation (DU) of fatty acid to match the international standards of cleaner biodiesel. OS in biodiesel has been met with the absence of linolenic acid. High saturated fatty acid provides high CN. The iodine value of feedstock oil met the European standard where the DU of the oils was less than 138. However, CFPP of refined cooking oil and waste cooking oil did not meet the demanding Spanish regional (RD 61/2006) standard due to the presence of stearic and palmitic acid, which tended to clog the fuel filter by precipitating while the biodiesel becomes cool. With the proposed triangular chart for biodiesel properties prediction, potential biodiesel fuels from various feedstock oils can be analysed.     

Neutronic and thermal hydraulic analysis for production of fission molybdenum-99 at Pakistan Research Reactor-1

Neutronic and thermal hydraulic analysis for the fission molybdenum-99 production at PARR-1 has been performed. Low enriched uranium foil (<20% ²³⁵U) will be used as target material. Annular target designed by ANL (USA) will be irradiated in PARR-1 for the production of 100 Ci of molybdenum-99 at the end of irradiation, which will be sufficient to prepare required ⁹⁹Mo/^99mTc generators at PINSTECH and its supply in the country. Neutronic and thermal hydraulic analysis were performed using various codes. Data shows that annular targets can be safely irradiated in PARR-1 for production of required amount of fission molybdenum-99.     

A network flow model for load balancing in circuit-switchedmulticomputers

In multicomputers that utilize circuit switching or wormhole routing, communication overhead depends largely on link contention-the variation due to distance between nodes is negligible. This has a major impact on the load balancing problem. In this case there are some nodes with an excess load (sources) and other with a deficit load (sinks). A matching of sources to sinks is required to avoid contention. The problem is made complex by the hardwired routing on currently available machines: The user can control only which nodes communicate but not how the messages are routed. Network flow models of message flow in the mesh and the hypercube have been developed to solve this problem. The crucial property of these models is the correspondence between minimum cost flows and correctly routed messages. To solve a given load balancing problem, a minimum cost flow algorithm is applied to the network. This permits the efficient determination of a maximum contention free matching of sources to sinks that, in turn, tells how much of the given imbalance can be eliminated without contention     

A new algorithm for the normal distribution function

In this paper new algorithms for the rapid, efficient and accurate evaluation of the standard normal integral and its tail are developed. It is shown how the accuracy of the computation can easily be improved so as to achieve machine accuracy for the particular computer being used.     

Influence of fatty acids content in non-edible oil for biodiesel properties

Physical and chemical properties of biodiesel are influenced by the structural features of fatty acid, such as with saturated, monounsaturated and polyunsaturated fatty acids. In this study, seven non-edible oils have been selected, which include waste cooking oil derived palm olein, Calophyllum inophyllum, jatropha oil, castor oil, rubber seed oil, kapok seed oil and karanja oil. The critical parameters, e.g. cetane number (CN), iodine value (IV) and oxidation stability (OS) of biodiesel were correlated with the degree of unsaturated (DU) fatty acid, whereas the cold filter plugging point (CFPP) was correlated with the long chain saturated factor (LCSF). To meet the minimum EU requirement of EN 14214 of the critical parameter, the DU value of the CN was ≤133.5, IV ≤123.2 and OS ≤98.9. The LCSF values satisfied the Spanish regional standard—RD 61/2006 in summer (0 °C) at ≤8.4 and winter (?10 °C) at ≤0.1 of the CFPP. Based on the composition of the saturated, monounsaturated and polyunsaturated fatty acids, a triangular chart for the biodiesel property prediction was developed. This can then be used as a reference for non-edible oils.