Vol. 14 Issue 3
A.M. Barry and I.H. Khan
The behaviour of an ARMA process for parameter values closer to unity has been of paramount interest in the literature. Various studies have been undertaken for this case. The present study undertakes the problem of a small parameter value when it is closer to zero and therefore the process being on the boundary of a white noise process. Some conventional procedures for identification of ARMA (1,0) process with small parameter values are evaluated using simulation
Amein K. Al-Ali, Fuad Qaw and Yousef Al-Yousef
The presence of a divalent metal ion together with a catalytic amount of inosine-5-diphosphate (IDP) are essential for the activation of phosphoenolpyruvate carboxykinase purified from kidney of Arabian camels. With decreasing order of effectiveness, the carboxylating activity was supported by the metal ions, Mn2+, Cd2+ and Mg2+. Combination of Mg2+ with micromolar concentrations of Mn2+ or Co2+ recovered full activity. However, high concentration of Cd2+ proved to be inhibitory, when combined with Mn2+ or Co2+ plus Mg2+. Gluconeogenesis regulation is assumed to run principally via the control of PEPCK. This plays an important role in maintaining a high glucose level in camels, in contrast to ruminants (in jensu strictu) which have a low glucose in blood.
Abdullah Shanableh
Water is a supercritical fluid at temperatures and pressures above the critical point, 374.2°C and 22.1 MPa. The unique properties of supercritical water (SCW) include complete solubility of oxygen and organic compounds, poor solubility of inorganic salts, improved mixing, enhanced mass transfer rates, and strong ability to dissolve organic solids. The recently developed supercritical water oxidation (SCWO) technology relies on the properties of SCW to create a useful and effective oxidation reaction medium. The oxidation of hazardous organic wastes and sludges can proceed to complete in SCW, and this can be achieved in a totally enclosed treatment facility. This paper described an investigation of SCWO for destruction of a highly contaminated biological sludge. The destruction of the organic contaminants was virtually complete in relatively short residence times. Above 99 percent chemical oxygen demand (COD) reduction was achieved within 5 minutes at 450°C, 15 minutes at 425°C and 25 minutes at 400°C. The process produced a clear and odorless effluent and a disposable ash with good settling characteristics. The process is applicable to a wide range of hazardous wastes and sludges and can become thermally self sustaining at low concentrations of organic wastes
E.M. Abdelrahman and S.M. Sharafeldin
The present paper deals with a simple and rapid approach to depth determination of a buried thin dike using numerical horizontal magnetic gradients. The problem of depth determination has been transformed into finding the zero anomaly distances from observed gradients. Formulas are also given to estimate the amplitude coefficient and the index parameter. The method has been applied to synthetic data and the validity of the method is tested on the Pima copper mine magnetic anomaly, Arizona.
A.M. Gheith and M. Abou Ouf
The study reported in this paper illustrates the geomorphologic features and sedimentological characteristics of coastal and inland sand dunes in the Shuayba coast, the southern Corniche of Jeddah, and along Jeddah and Makkah highway. The geomorphologic features are studied on basis of dune type, modification, wind ripples, and internal structures.
Differentiation between coastal and inland dune sands has been based on grain-size parameters, cumulative curves, bivariate plots and mineralogy. Inland dune sands are finer, and better sorted with single saltation populations as compared to coastal dune sands.
The heavy mineral suites of both sand dune types display a dominance of less stable minerals (e.g. amphiboles and pyroxenes) over the stable ones (e.g. zircon, tourmaline and rutile).
It is concluded that the local topography and sand-carrying winds affect the distribution and morphology of the inland sand dunes along Jeddah and Makkah highway.
A.A. Alhamid, D. Husain and Abdel-Azim M. Negm
A combined weir consisting of a sharp-crested rectangular contracted weir and an inverted triangular weir below is a flow regulation device used in irrigation works for diverting the flow from a main channel to a secondary channel. The present practice for computing the discharge for classical rectangular and triangular weirs is from curves or equations relating the discharge coefficient and the upstream depth/gate opening ratio parameter including weir geometry, and tailwater depth/gate opening ratio being the fourth parameter which is needed to be updated. The discharge for simultaneous flow still in addition involves few more parameters: the distance between the weirs, the slope of the apron, the opening depth and weir angle. In this paper one generalized equation including all the important variables is obtained from the experimental investigations. This equation is suitable for both horizontal and sloping channel bed under submerged flow and for the free flow, the tailwater depth/weir opening ratio term being neglected. The predictions of the equation agreed well with the experimental data.
A.S. Abu Ruwaida, W.N. Sawaya, A.S. Hussain, Z. Baroon and S. Khalafawi
Temperatures in 38 display freezer cabinets and 31 large freezers (bulk storage) of food outlets were monitored to determine market storage temperatures of frozen poultry meat in Kuwait. Data showed that the storage temperatures were too high. Frozen poultry meat stored under simulated market storage conditions showed a rapid increase in spoilage microorganism counts when stored at -5°C, whereas counts in carcasses stored at -18 and -12°C did not substantially change over 12 months of storage. The counts of psychrotrophic bacteria increased from log 3.4 to 7.2 CFU/ml after three months storage at -5°C and was accompanied by changes in the meat's sensory and organoleptic properties, increased values of total volatile nitrogen, free fatty acids and peroxides. No substantial changes were observed in extract release volume. Data also showed relatively high initial counts of E. coli and coliforms, (average log 3.2 and 3.4 CFU/ml rinse, respectively), indicating poor sanitation during slaughtering and processing. These counts decreased with increasing frozen storage, but the decrease rate was higher at lower temperatures (-18°C) than at higher temperatures (-12 and -5°C). Salmonella was present in 60-80% of examined frozen carcasses, and this incidence rate did not substantially change during prolonged frozen storage. Campylobacter and Staphylococcus aureus were detected in all examined frozen carcasses at relatively high levels (average log 2.9 and 4.4 CFU/ml rinse, respectively). These levels decreased (by about 1 and 1.5 log cycles, respectively) with increasing frozen storage, especially in carcasses stored at lower temperatures (-18°C), Freezing and/or prolonged frozen storage generally reduces, but did not render the poultry completely free of bacterial flora.
A.M. Attalla and F.M. Harraz
In this study, the pits of eleven selected date palm cultivars grown in the Qassim region were analyzed (on dry weight basis) for their elemental composition as well as organic constituents. Regarding the elemental composition, their concentration ranges in the pits of the studied cultivars were as follows: Nitrogen, 0.81-1.20%; phosphorus, 0.186-0.259%; potassium, 0.363- 0.403%; calcium, 0.357-0.422%; magnesium, 0.104-0.153%; chloride, 0.269-0.507%; sodium, 0.029- 0.043%; iron, 124.8- 172.0 µg/g; manganese, 17.0- 24.8 µg/g; zinc, 8.3- 18.3 µg/g; and copper, 8.8- 17.3 µg/g, while the concentration ranges of the organic constituents were as follows: total carbohydrates, 57.645- 68.918%; total sugars, 3.773- 5.830; total proteins, 5.11- 7.52%; crude fats, 8.67- 12.31%; and tannins, 1.59- 3.48%. Significant differences were also observed among the studied cultivars in most of their mineral and organic constituents.
Significant correlation coefficients were found among the mineral composition and organic constituents of the pits of the selected cultivars in most cases.
Hago M. Abdel Magid, Raafat K. Rabie, Ragaa E. A. Sabrah, and Shafik I. Abdel-Aal
The relationship between microbial numbers and rate of application and biodegradation products (mainly CO2 and NH3 evolution) of chicken manure (C.M.) and municipal refuse (M.R.) was determined using the data obtained during field incubation studies under centre-pivot sprinkler irrigation in Central Saudi Arabia.
Microbial numbers increased with increasing rate of manure application and with incubation time. Maximum microbial proliferation coincided with the optimum (feasible) rates of application of both manues with respect to CO2 evolution previously reported by Abdel Magid et al. (1993). In microbial growth rate terms the effect of the optimum rate of application was more pronounced with C.M. than with M.R. at the 16th week of incubation.
After 16 weeks, highly significant correlations were obtained between microbial numbers and rates of treatment application, cumulative CO2 and cumulative NH3. The highest rates of CO2 and NH3 evolution coincided with the optimum rates of application of both manures.
A laboratory study of the effect of temperature on NH3 evolution during the biodegradation of C>M. revealed that at high rates of application the magnitude of the temperature coefficient (Q10) of NH3 evolution is affected by the rate of application irrespective of temperature. At application rates higher than the optimum biodegradation was insensitive to temperature.
The results obtained confirm our previous findings that the optimum economic rates of application of C.M. and M.R. occur between 8.25 to 16.5 and between 16.5 to 33.0 tonnes/ha, respectively.
H.A. Al-Mana and R.M. Mahmoud
Five durum wheat cultivars, CHAMI, YOVAROS, SEBUO 4, KOREFLA, and K.F.U.I. were subjected to detailed physical, chemical, mixing, cooking and sensory tests to evaluate their flour performances for spaghetti-making quality. Test weights for all cultivars have met the specification for European Union (EU) durum wheat. Only CHAMI and SEBUO 4 were characterized by larger kernel size while YOVAROS and K.F.U.I. were about 30% less in yellow color intensity than other cultivars. In spite of all cultivars being generally of higher protein contents, they varied in their mixing characteristics. Wheat ash contents ranged from 1.39 to 2.21%, and falling numbers were from 63 to 872 sec.
Spaghetti samples prepared from all cultivars, except, K.F.U.I. were characterized by lower cooking losses, and an extremely high cooking loss (17%) was observed for spaghetti prepared from K.F.U.I. In addition, cooked spaghetti samples rom all cultivars except YOVAROS and K.F.U.I. had an intense desirable yellow color.
Sensory panel evaluation of cooked spaghetti revealed that spaghetti from CHAMI and SEBUO 4 had excellent overall sensory properties as indicated by good firmness and almost absent stickiness and bulkiness. To the contrary, spaghetti from YOVAROS and K.F.U.I. had poor sensory attributes as indicated by insufficient firmness and high or very high stickiness and bulkiness. Only spaghetti prepared from KOREFLA was rated air as indicated by sufficient firmness and high stickiness and rare bulkiness.