Showing papers by "Cairo University published in 1988"

Attitudes of Urban Sudanese Men Toward Family Planning

Abstract: Using data from the Male Attitude Survey of 1985, this paper shows that Sudanese men play a major role in family planning decision-making. Attitudes regarding family planning issues are presented for 1,500 men aged 18 years and over, living in urban areas of Khartoum, the capital of Sudan. The decision not to practice family planning is found to be male-dominated, and husbands are responsible for providing contraceptives when family planning is practiced. Widespread misconceptions about vasectomy, along with a very low acceptance rate, exist among the men in the sample. It is concluded that the involvement of men in family planning programs will give these programs a better chance of success in the future.

Nitriles in heterocyclic synthesis: Novel syntheses of benzo[ b ]pyrans, naphtho[1,2- b ]pyrans, naphtho[2,1- b ]pyrans, pyrano[3,2- h ]quinolines and pyrano[3,2- c ]quinolines

Abstract: Synthese des composes du titre a partir de cinnamonitriles et de phenols, quinoleinol-8, naphtols et de dihydro-1,2 hydroxy-4 methyl-1 quinolone-2

Photosynthetic pathways, distribution, and ecological characteristics of grass species in egypt

Abstract: This study is based both on our own results, especially δ13C analyses, and on data in the literature. Of the 225 species of Poaceae reported from Egypt, 105 species show the C3 and 120 the C4 type of photosynthetic CO2 fixation. Winter annual and perennial grasses active in winter are mainly C3 species, while summer annuals and the other perennials are mainly C4 species. The percentage of C3 species decreases with decreasing latitude. This seems to be mainly related to increasing temperatures. The C3 grass species are found preferentially in the Mediterranean, Irano-Turanian, Mediterranean/Irano-Turanian, and Saharo-Arabian chorotypes, while the C4 species are mainly found in the Sudanian, Saharo-Arabian/Sudanian and Tropical chorotypes. In Egypt, the NADP+-ME and NAD+-ME subtypes of C4 photosynthesis are found in about equal numbers of C4 species, while the PCK subtype is relatively rare.

Reactions with hydrazidoyl halides ii [1]: synthesis and reactions of 2-bromothienylglyoxal-2-phenylhydrazone

Abstract: 2-Bromoacetylthiophene reacted with dimethylsulfide in ethanol to afford dimethylsulfonium bromide 2, which reacted with N-nitrosoacetanilide to give 2-bromo-thienylglyoxal-2-phenylhydrazone (3). 3 reacted with pyridine and with triphenylphosphine to give 4a and 4b, respectively. 3 reacted also with morpholine, sodium thiophenolate or potassium cyanide to afford the corresponding hydrazones 5a–c, respectively. 3 reacted also with potassium thiocyanate and with potassium selenocyanate to give the thiadiazoline 6a and selenadiazoline 6b. 3 is utilized also for the synthesis of several heterocycles via its reactions with malononitrile, benzoylacetonitrile, dibenzoylmethane, ω-benzenesulfonylacetophenone, N-arylmaleimides and benzalaniline. Structural assignments have been made on the basis of elemental analyses, spectral data and independent synthesis wherever possible.

Calculation of Turbulent Flow and Heat Transfer in Channels With Streamwise-Periodic Flow

Abstract: A computational method for the calculation of the flow and heat transfer in a channel, with elements of various heights inducing a streamwise-periodic flow, is presented and evaluated. The time-averaged conservation equations of mass, momentum, and energy were solved together using a finite-control-volume method. Reynolds stresses were obtained using a two-equation model, which solves the time-averaged equations of the turbulence kinetic energy and its dissipation rate. The calculated flow field is shown to be in satisfactory agreement with the experimental data. The results indicate that the local and overall heat loss parameters increase with increasing Reynolds and Prandtl numbers and element height and with decreasing spacing.

Columnaris infection among cultured Nile tilapia Oreochromis niloticus.

Abstract: Flexibacter columnaris was isolated from 13 culturedOreochromis niloticus showing respiratory disorders. The isolates developed typical swarming rhizoid colonies on Cytophaga agar medium. Antibiotic sensitivity test revealed the susceptibility ofF. columnaris isolated to oxytetracycline, chloramphenicol and erythromycin. A marked difference in the pathogenicity of seven tested isolates was observed: two were highly virulent, one was moderately virulent and four were avirulent. No experimental infection could be induced with the highly virulent isolates except after injuring one of the natural barriers of the fish body. The severity of the disease and the increased median death time shortened by keeping infected fishes with injured gills in water containing ammonia. In naturally infectedO. niloticus, the disease became chronic as indicated by the presence of excessive proliferative and necrotic changes. On the other hand, severe dilatation of branchial blood vessel, oedema and round cell infiltration proved that, the disease among experimentally infected tilapias was acute.

New method for transmission planning using mixed-integer programming

Abstract: The authors present a new approach for planning high voltage transmission networks. The simulation model developed takes into account the capital investment cost in its discrete form as well as the cost of transmission losses. The constraint equations include the DC load flow equations and line loading constraints. The voltage loop equations are written in a modified form, such that a close-loop equation will be ineffective if any line of this loop is deleted. The simulation model utilises the mixed-integer linear programming technique to obtain the least-cost network satisfying line loading constraints. Verification of the method is made through a test example.

Nitriles in Heterocyclic Synthesis: Novel Synthesis of Pyrido-[2,1-b]benzothiazoles and 1,3-Benzothiazole Derivatives

Abstract: Novel synthesis of pyrido[2,1-b]benzothiazoles, pyridine, pyran, thiopyran, pyridazine and coumarin derivatives utilising benzothiazol-2-ylacetonitrile, as starting component are reported. Aktivierte Nitrile in der Heterocyclen-Synthese: Neue Synthese von Pyrido[2,1-b]-benzothiazolen und 1,3-Benzothiazol-Derivaten Verschiedene neue Pyrido[2,1-b]benzothiazoles, Pyridin-, Pyran-, Thiopyran-, Pyridazin- und Cumarin-Derivate wurden ausgehend von Benzothiazol-2-ylacetonitril synthetisiert.

Absolute valued algebras with an involution

Abstract: Let A be an absolute valued algebra with involution, in the sense of Urbanik [K. Urbanik, Absolute valued algebras with an involution, Fund. Math. 49 (1961) 247–258]. We prove that A is finite-dimensional if and only if the algebra obtained by symmetrizing the product of A is simple, if and only if eAs = As, where e denotes the unique nonzero self-adjoint idempotent of A, and As stands for the set of all skew elements of A. We determine the idempotents of A, and show that A is the linear hull of the set of its idempotents if and only if A is equal to either McClay’s algebra [A.A. Albert, A note of correction, Bull. Amer. Math. Soc. 55 (1949) 1191], the para-quaternion algebra, or the para-octonion algebra. We also prove that, if A is infinite-dimensional, then it can be enlarged to an absolute valued algebra with involution having a nonzero idempotent different from the unique nonzero self-adjoint idempotent. © 2005 Elsevier Inc. All rights reserved.

The flavonoids ofBalanites aegyptiaca (Balanitaceae) from Egypt

Abstract: Six flavonoid glycosides: quercetin 3-glucoside, quercetin-3-rutinoside; 3-glucoside, 3-rutinoside, 3-7-diglucoside and 3-rhamnogalactoside of isorhamnetin were extracted and identified from the leaves and branches of Egyptian material ofBalanites aegyptiaca. Only isorhamnetin: 3-rutinoside and 3-rhamnogalactoside were recorded from the fruits of the same plant.—Phytochemical aspects ofBalanites aegyptiaca and some genera ofZygophylaceae s. l. viz.Nitraria, Fagonia, Zygophyllum, Seetzenia andTribulus support its affinities with that family.

On the solvability of finite groups

Abstract: Let M be a subgroup of a finite group G. We define the core of M in G by Cor G (M) = ∩ g∈G M g . Clearly, Cor G (M) is the largest normal subgroup of G contained in M. We determine the structure of a finite group G if G possesses a maximal subgroup with core 1 and all maximal subgroups M of G with Cor G (M) = 1 satisfy a certain property.

Variation in Reaction of Faba Bean Lines to Different Accessions of Orobanche crenata Forsk.

Abstract: Three pot experiments were earned our to investigate the variation among geographic accessions of Orobanche crenata Forsk. in their ability to attack different stocks of Vicia faba L. Orobanche accessions were quite different in their influence on the performance of genetic lines of the host. However, host parasite relationships appeared to be dependent upon environmental conditions. The usefulness or host genotypes for differentiating between parasite accessions was rather limited. The number of Orobanche shoots per host plant does not appear 10 be a precise indicator of host tolerance although it has been frequently used for this purpose.

A new monitor for pollution on power line insulators. II. Simulated field tests

Abstract: An apparatus is developed for monitoring the leakage currents drawn by an insulator chain of a power line or a busbar support in a polluted atmosphere. The apparatus monitors the insulator pollution by sensing and analysing the leakage current bursts. If these bursts are judged by the apparatus as corresponding to a potentially dangerous pollution level, the apparatus transmits an alarm signal to the service crew to allow them to clean the insulators of the line or substation in time before a sudden line outage occurs, with the entailed excessive expense, loss of power supply and annoyance to customers. Line insulator cleaning is thus carried out only when necessary, which adds to the economy of the power system operation. The apparatus design and construction were reported in Part 1 of the paper. It has undergone numerous tests with artificially polluted insulators in the high voltage laboratory. These tests are the subject of the present paper. The following Part, to be submitted, will describe field experience.

Multi-project scheduling: a new categorization for heuristic scheduling rules in construction scheduling problems

Abstract: After more than two decades of applying CPM as a planning and scheduling technique there is growing doubt about some of the advantages initially attributed to it It is being discarded by both large and small construction companies, and its use limited to cases where it is required by the clients Some planners and schedulers have begun to depend on their own experience The author has developed a heuristic planning and scheduling model which uses two new criteria: the tightness degree of completion due-dates and resource tightness degrees Throughout the scheduling experiments, the hypothetical relationship between the performance of the proposed heuristic scheduling rules and the degrees of completion due-dates and resource tightness proved to be correct and there is a significant difference between the performance of proposed heuristic scheduling rules in the different scheduling classes The new classification of scheduling problems proved to be practical, effective and helpful The scheduling experim