A Microbiological Study of Sudanese Date Wines

Procedures followed in the home fermentations of three date wines were investigated. Two wines, 'sherbote', and‘nabit’prepared from date sirup, are produced by a relatively quick fermentation taking about 36-48 hr. The fermentation of the third wine;‘dakkai', prepared from whole date fruits, is a slow process taking about 96 hr. The samll amounts of spices and sorghum malt used as additives in the preparation of 'sherbote’and‘nabit', respectively, contribute to the inoculum. In‘dakkai’fermentation of the inoculum comes from the natural flora of the data fruit itself. Changes in the production of ethanol, acetic and lactic acids and pH as well as in microbial populations were followed during fermentation of each wine. The most important genera of yeast, acetic and lactic acid bacteria were identified.     

Natural ray-emitting radionuclides in Egyptian cement

1Introduction Radionuclides occurring naturally in building materials are sources of external and internal radiation exposure in dwellings.The most important naturally occurring radionuclides present in soil and rocks are226Ra,232Th and40K.Since these radionuclides are not uniformly distributed,the knowledge of their distribu-tions in soil and rocks plays an important role in ra-diation protection and measurement.[1,2]In the forth-coming years lower regulatory limits are likely to be-come ob…     

PREVALENCE OF ANTIMICROBIAL RESIDUES IN MILK AND DAIRY PRODUCTS IN THE STATE OF KUWAIT

ABSTRACT

Approximately, 1,000 locally produced and imported milk and dairy product samples were collected at different seasonal periods from different farms and retail outlets in Kuwait, and screened for the presence of four antimicrobial residues (beta‐lactams, tetracyclines sulfonamides and chloramphenicol) using Charm II system. Results indicated that 29.1% of the analyzed local fresh milk samples were above the maximum residue level (MRL) for tested residues with tetracycline as predominant residue. The prevalence of antimicrobial residues in imported pasteurized milk samples (5.4%) was higher than that of local pasteurized milk samples (3.4%). No residues were detected in powdered and condensed milk samples imported from the European Union (EU) countries with the exception of tetracyclines. Results also showed that 9.4% of the analyzed imported cheese samples were above the MRL for tested residues, while tested ice cream samples were negative for antimicrobial residues. The significant presence of antimicrobial residues, particularly chloramphenicol, in raw and pasteurized milk, clearly implies the misuse of antimicrobial drugs in animal farms in Kuwait and neighboring countries, and implies the need for stricter regulations on antimicrobial drug usage in the dairy industry.

PRACTICAL APPLICATIONS

This article addresses the generation of a baseline data on the current presence of four antimicrobial residues in locally produced and imported milk and dairy products in the state of Kuwait. The outcome of this study will provide valuable baseline information for local governmental authorities for effective monitoring for the use and misuse of agricultural antimicrobial drugs. Such data will also be important for other Gulf Cooperation Council countries, because such countries share similar farming practices and import comparable foodstuffs.

     

LOSS REDUCTION IN DISTRIBUTION NETWORKS USING NEW NETWORK RECONFIGURATION ALGORITHM

ABSTRACT

Network reconfiguration is an operation task, and consists in the determination of the switching operations such to reach the minimum loss conditions of the distribution networks. In this paper, a general formulation of the network reconfiguration for loss minimization is given for the optimization of distribution loss reduction and a solution approach is presented. The solution employs a search over different radial configurations, created by considering branch exchange type switches. The solution algorithm for loss minimization has been developed based on the two stage solution methodology. The first stage of this solution algorithm finds a loop which gives the maximum loss reduction in the network. For this purpose a simple-to-use formula, called loop loss reduction formula, has been developed. To find a branch exchange, which results in the maximum loss reduction in the loop, the second stage applies a proposed technique called distance-center technique. Therefore, the solution algorithm of the proposed method can identify the most effective branch exchange operations for loss reduction, with a minimum computational efforts. The solution algorithm of the proposed method has been tested, with very promising results, on a 69-bus radial distribution system. Test results prove that, via proposed network reconfiguration for loss minimization, real power loss is reduced significantly, and that the voltage profile of the network is considerably improved. As compared to the established methods the proposed method eliminates the need to run numerous load flows.     

OPTIMAL COMPENSATION OF NONUNIFORMLY LOADED RADIAL FEEDERS,WITH APPLICATIONS

ABSTRACT

This paper presents a generalized mathematical model for assessing the loss reduction in nonunlformly loaded radial feeders by capacitor shunt compensation. The model allows for the simultaneous presence of linearly increasing feeder load density in addition to a concentrated load at the feeder end. Any number of compensating capacitors can be included in the analysis. The model is then applied to study the effect of the number of feeders on the achieveable optimal reduction in the feeder copper loss. The paper also gives the optimal size and locations of these capacitors, for any number of radial feeders eraenatlng from a distribution substation to serve a certain total load.     

COMPOSITE RELIABILITY EVALUATION OF INTERCONNECTED POWER SYSTEMS

ABSTRACT

A power network can be divided into several subsystems such as generation, transmission and distribution subsystems. The most popular approaches for reliability evaluation, namely contingency enumeration and Monte-Carlo simulations, have been combined in this paper to form a hybrid algorithm for reliability assessment of composite generation and transmission subsystems. The main objective of this hybrid approach is to enumerate transmission outages and then sample generation states, conditioned to each enumerated transmission state, to evaluate the annualized reliability indices of the entire system and different load centers

Within the proposed hybrid algorithm for generation rescheduling, correction of voltage levels or alleviating of component overloading in order to minimize the amount of load curtailment, a linear programming model is implemented. This algorithm has been utilized for assessing the reliability of the Unified Egyptian Power System. Moreover a weak point analysis is carried out to define the different measures to improve the system reliability. These measures include generation capacity addition, increasing transmission capacity or regional interconnection with other utilities.     

Formation and potential uses of milk proteins as nano delivery vehicles for nutraceuticals: A review

The aim of this review was to highlight the progress achieved in the use of milk protein as nano vehicles for nutraceuticals. Reassembled casein and β‐casein micelles and core/shell nanoparticles from casein with other biopolymers have been prepared. Also, cross‐linking of casein micelles has developed stable nanoparticles. Nanogels of whey proteins (WP), β‐lactoglobulin (β‐LG) and lactoferrin (Lf) have been prepared by controlled thermal treatment, and several core/shell nanoparticles have been developed from WP or β‐LG with several polysaccharides. The developed caseins and WP nanoparticles have been used as carriers for several nutraceuticals. Examples have been presented and discussed.     

SOLUBILITY AND DIFFUSIVITY OF GASES IN AN ORGANIC SOLUTION OF AMINE

Solubilities and diffusivities of carbon dioxide and nitrous oxide in a mixture of toluene and isopropanol organic solution of cyclohexylamine were measured at 20°C in the range of pressures of solute from 1 to 3 bars. This was performed with an original chromatographic technique taking into account the presence of the product of the reaction.     

ECONOMICAL GENERATION RESERVE IN ISOLATED POWER SYSTEMS

ABSTRACT

This paper presents a new technique to determine the economical generation reserve for isolated power systems. The reserve is classified as short-term and long-term. For planning short-term power reserve to determine the required load shedding for avoiding blackout for severe emergency conditions, the dynamic behavior of the system after generating unit outages is performed, and the resulting frequency decay is analyzed. Therefore, the economical short-term reserve is determined to minimize the summation costs for reserve provision, plus the equivalent cost of the required load shedding.

For planning of long-term reserve, the utility investments and other decisions factors that affect electric service reliability should be explicitly evaluated, on the basis of their cost and benefit implications. A cost benefit approach, that quantifies the power reserve benefit in terms of the reduction in unserved energy cost, enables the evaluation of generation capacity additions.

To determine the economic short-term and long-term generation reserve, these approaches have been applied to areal regional utility