Showing papers by "Ain Shams University published in 1973"
TL;DR: Analysis of l -ascorbic acid, certain pharmaceuticals, and foodstuffs by the proposed method and the N -bromosuccinimide method for similar results is reported.
40 citations
29 citations
TL;DR: Heat resistance parameters were determined for these spores in distilled water and in different juices and brines and sodium chloride increased the thermal resistance of B. megaterium spores and this effect was independent of NaCl concentration of 2–15%.
Abstract: .
Spores of Bacillus subtilis, B. cereus, B. megaterium and B. pumilus were isolated from canned products. Heat resistance parameters were determined for these spores in distilled water and in different juices and brines. D values for B. subtilis, B. cereus, B. megaterium and B. pumilus suspended in distilled water were 1·5, 0·8, 1·6, and 1·5 min at 212°F. The D value for B. stearothermophilus in water was 3μ4 min at 248°F. Both D and Z values were reduced when spores of B. megaterium were heated in orange and mango juices. Similarly, spores of B. stearothermophilus were destroyed in okra brine faster than in water. Sodium chloride increased the thermal resistance of B. megaterium spores and this effect was independent of NaCl concentration of 2–15%. Pectin also conferred some protection against heat inactivation of spores of B. megaterium but sucrose had no effect.
24 citations
TL;DR: In this article, closed-form expressions in terms of Mathieu functions have been obtained for the cutoff frequencies and eigenfunctions describing the field distribution for different modes in doubly and quadruply ridged guides of circular cross section.
Abstract: Cutoff wavelengths of TE and TM modes in doubly ridged guides of elliptical cross section have been calculated using an exact method. Closed-form expressions in terms of Mathieu functions have been obtained for the cutoff frequencies and eigenfunctions describing the field distribution for different modes. These solutions are further extended to include the case of doubly and quadruply ridged guides of circular cross section and to calculate the slot coupling of two waveguides with semielliptical or circular cross sections. The dual problem of the coaxial strip guide has also been treated using the same method.
24 citations
01 Jan 1973
TL;DR: Investigation of the setae on the first tarsus of the hard ticks, Amblyomma americanum and Haemaphysalis, revealed the presence of chemo- and mechanoreceptors, judging from ultrastructural characteristics.
Abstract: Sensory receptors in Acari are poorly known although extensive research has been reported on other Arthropoda, particularly Insecta. Our investigations of the setae on the first tarsus of the hard ticks, Amblyomma americanum (L.) and Haemaphysalis (Alloceraea) inermis Birula revealed the presence of chemo- and mechanoreceptors, judging from ultrastructural characteristics. A consistent pattern of distribution of tarsal sensilla in the region of Haller’s organ was observed, by scanning electron microscopy (SEM), in the different species and life stages. Presumably chemoreceptive sensilla, resembling one type in the ticks, were found on the first tarsus of the mesostigmatid mite, Macrocbeles muscaedomesticae (Scopoli).
16 citations
TL;DR: In this article, the effect of a typical corrosion stimulant, namely calcium chloride, was investigated, when present, either alone, or mixed with various inhibitors in the cement paste, and the critical concentrations required of some various inhibitors to counteract the influence of calcium chloride were determined.
15 citations
TL;DR: Experimental CO2 and cyanide gas exposure provide evidence of a mechanism for opening and closing the spiracle and involving the ostial lip and atrial valve that appears to depend on hemolymph pressure and action of atrial and other body muscles.
Abstract: The spiracular structure of Haemaphysalis hoodi, H. kinneari, H. punctata, H. longicorms, and Boophilus microplus is described as seen by light and scanning electron microscopy (SEM), and is discussed in relation to previous reports on the structure and function of tick spiracles. Surface pores and a prominent lip-guarded ostium in the spiracular plate are readily observed by SEM and also in histological sections. Goblets in the peripheral part of the spiracular plate open to the exterior by pores and connect the hypodermal epithelium with fine canals apparently containing sensory sensilla. Experimental CO2 and cyanide gas exposure provide evidence of a mechanism for opening and closing the spiracle and involving the ostial lip and atrial valve. This mechanism appears to depend on hemolymph pressure and action of atrial and other body muscles.
14 citations
TL;DR: In this article, concentric rings whose center serves as a fiduciary point and a compensation method is applied to dispersion, refraction, length or phase shift measurements are pointed out.
13 citations
TL;DR: Blood serotonin at delivery showed a highly significant increase, nearly reaching double the normal values, in mild and severe pre-eclamptic patients as compared to normal pregnant women, and the corresponding placentas showed nearly the same results.
11 citations
11 citations
TL;DR: A monovalent specific antivenin was prepared in horses against the Egyptian cobra (Naje haje) venom; using bentonite as an adjuvant and proved effective in neutralization of and protection against these venoms.
TL;DR: It is proposed that such injuries be classified into two types: 1) displacement of the radial head without dislocation of the elbow; and 2) displacement during posterior dislocationof the elbow.
Abstract: 1. Three cases of fracture of the neck of the radius with medial displacement of the head are described. 2. It is proposed that such injuries be classified into two types: 1) displacement of the radial head without dislocation of the elbow; and 2) displacement during posterior dislocation of the elbow.
TL;DR: In this paper, the solid state ion-selective chloride and bromide electrodes were used for the micro determination of chlorine and Bromine in organic compounds after combustion in an oxygen-filled flask, potentiometric titration with silver nitrate at pH 5-7 in presence of 50% dioxan was carried out.
Abstract: The solid state ion-selective chloride and bromide electrodes are used for the microdetermination of chlorine and bromine in organic compounds. After combustion in an oxygen-filled flask, potentiometric titration with silver nitrate at pH 5–7 in presence of 50% dioxan is carried out. Results accurate to ±0.3% absolute are obtained with some partially and highly halogenated compounds.
TL;DR: In this article, low-porosity portland cement pastes were prepared by pre-hydration compression at 5, 10, 30 and 70 atmospheres, followed by hydration in liquid water at 25°C for about two years.
TL;DR: The moth longevity was increased by decreasing the tempereature, and female moths lived longer than males, and the total number of eggs laid per female were increase by decreasing temperature.
Abstract: An increase in temperature or relative humidity shortened the incubation period of eggs of Attacus ricini. At high temperature (30° C) and low humidity, (30%), all eggs failed to hatch. Data show an obvious increase in the percentage loss in weight of eggs with rise of temperature and decrease of humidity. The percentage of hatched eggs seems to be much affected by high temperature and low humidity. 25° C and 90% R.H. could be regarded as the optimum conditions for hatching.
The larva passes through five instars, the first is the shortest, the last one being the longest. The prepupal stage occupies nearly the second half of the fifth larval instar. The duration of the larval stage is shortened by high temperatures.
The pupal duration is much affected by temperature, but no apparent effect could be related to humidity or sex. Under conditions of low humidity and high temperature, pupae lose much weight.
The moth longevity was increased by decreasing the tempereature, and female moths lived longer than males. The preoviposition, the oviposition and the postoviposition periods as well as the total number of eggs laid per female were increased by decreasing temperature.
Zusammenfassung
Zur okologie des Seidenspinners Attacus ricini Boisd. in agypten
Ansteigende Temperaturen oder Luftfeuchte verkurzen die Ei-Entwicklung von A. ricini. Bei hoher Temperatur (30° C) und geringer LF (30 %) schlupften keine Eier mehr. Die Eier nahmen mit ansteigender Temperatur und abnehmender Luftfeuchte an Gewicht ab. Der Prozentsatz geschlupfter Eier war am hochsten bei 25° C und 9% LF. Die Larven hauten sich 4X; das 1. Stadium ist das kurzeste, das 5. das langste. Die Larven-Entwicklung verkurzte sich mit zunehmender Temperatur. Die Puppendauer nahm bei erhohter Temperatur ab, zeigte jedoch keine Beziehung zur Feuchtigkeit. Bei geringer LF und hoher Temperatur verloren die Puppen beachtlich an Gewicht. Die Lebensdauer des Falters stieg mit abnehmender Temperatur, wobei ♂, ♂ langer als ♀, ♀ lebten. Die Ei-Entwicklungsdauer nahm ebenso wie die Eizahl mit fallender Temperatur zu.
TL;DR: Comparison of polyvalent and monovalent N. nigricollis antivenins, revealed that while thepolyvalent serum was of better effectiveness against the Egyptian viper venoms especially cerastes venoms, more protection was provided by themonovalent serum against the naja venoms.
TL;DR: In this paper, the authors investigated the influence of recurrent magnetic storms on the periodic phenomena in the data, in particular the 27-day variation, and an attempt has been made to remove disturbed periods from the data.
Abstract: Periodic variations in geomagnetic activity have been investigated, in the range from 4 to 40 days, by means of power spectrum analysis during the period 1932 to 1969. Main periodicities are found to exist at periods of 28.7, 13.3, 9.1 and 6.9 days. To investigate the influence of recurrent magnetic storms on the periodic phenomena in the data, in particular the 27-day variation, an attempt has been made to remove disturbed periods from the data. The variation of the power density at different frequencies–particularly the 27-, 13-, 9- and 6-day variation–with the solar cycle has been investigated. An average value of the period of the 27-day variation has been determined by means of a modified power spectrum technique. A high correlation with the solar cycle has been found and possibilities of a multiple cycle have also been discussed.
TL;DR: Oil ether extract of cotton leaves was the most attractive to the hatched larvae of Spodoptera littoralis, and it remained so even after removal of the chlorophyll and other pigments, and this fraction proved to be a hydrocarbon.
TL;DR: Although lorazepam was more potent on a weight for weight basis than diazepam, fewer ataxic effects attended its use, and it was significantly superior to placebo and measurably superior todiazepam in anxiolytic effect.
Abstract: Lorazepam was compared to diazepam and placebo under double-blind conditions in an ambulatory and hospitalized patient population suffering from anxiety symptoms. Lorazepam was significantly superior to placebo and measurably superior to diazepam in anxiolytic effect; diazepam was also significantly superior to placebo but to a lesser degree. Although lorazepam was more potent on a weight for weight basis than diazepam, fewer ataxic effects attended its use.
TL;DR: Monovalent Naja nigricollis antivenin was prepared in horses using venom adsorbed to bentonite (first three injections) followed by increasing doses (up to 50 mg) of unmodified venom.
TL;DR: In this article, simple and accurate methods for the micro determination of arsenate and arsenite ions using 12-and 14-fold amplification reactions using 12 and 14fold amplification were described.
Abstract: Simple and accurate methods are described for the microdetermination of arsenate and arsenite ions using 12- and 14-fold amplification reactions The arsenate method is based upon reaction with calcium iodate and iodometric titration of the liberated iodate, whereas the arsenite method depends upon reaction with iodine and oxidation of the resulting iodide with bromine This is followed by iodometric titration of the iodate in addition to the arsenate present in solution The overall recovery amounts to 9951 and 9963% for arsenate and arsenite respectively
TL;DR: The constitution of the products has been investigated by means of IR and UV spectra as mentioned in this paper, and the results showed that 3-benzal-2-thiophthalide 7a and p-methoxybenzalphide 7c react with 2b (1:1 mol.) to give 5 and 10 (a and b).
Abstract: Thiophthalic anhydride 1 reacts with the GRIGNARD reagents 2a–e (1:1 mol.) to give the corresponding 3-aryl(alkyl)-3-hydroxy-2-thiophthalides 3a–e. The interaction of 1 with 2c and f (1:2 mol.) yields the corresponding 1,2-diaroylbenzene derivatives 4. On the other hand, 1 reacts with 2b (1:2 and 1:3 mol.) to give 5 and 6, respectively.
When 3-benzal-2-thiophthalide 7a and 3-p-chlorobenzalphthalide 7b are allowed to react with the GRIGNARD reagents 2c–f, the corresponding indenone derivatives 8 are obtained. On the other hand, the reaction of 7a and b with 2b (1:2 mol.) yields 6 and 9, respectively. 7a and p-methoxybenzalphthalide 7c react with 2b (1:1 mol.) to give 5 and 10 (a and b).
The constitution of the products has been investigated by means of IR and UV spectra.
TL;DR: In this paper, the characteristic properties of selenium: density d, logarithm of electrical conductivity logσ, and activation energy ΔE g with addition of 5 at% sulphur and tellurium was measured for the glassy state and for the crystalline state.
Abstract: The characteristic properties of selenium: density d , logarithm of electrical conductivity logσ, and the activation energy ΔE g with addition of 5 at% sulphur and tellurium was measured for the glassy state and for the crystalline state. The process of transition of the amorphous into crystalline selenium was followed by measuring these quantities for all intermediate stages. Both S and Te decrease the rate of crystallization of selenium. In the crystalline state, the presence of S and Te increases the energy of activation of the conductivity process.
TL;DR: In this article, the Kohn variational method with a multi-parameter trial wave function has been applied to the low-energy s-wave elastic scattering of positrons by helium atoms.
TL;DR: In this paper, a new spot test reaction was described for the identification of some phosphorus nerve gases, which is based on peroxidation of the nerve gas with 5% urea peroxide in 3% potassium-sodium carbonate followed by a reaction with thallium(I) sulfate to form a yellow color or precipitate of thalli(III) oxyhydrate.
TL;DR: The present paper is concerned with the numerical solution of the synthesis problem for optimal linear distributed control systems, via a specific direct method, where the control function is represented by a finite number of conveniently chosen functions.
Abstract: The present paper is concerned with the numerical solution of the synthesis problem for optimal linear distributed control systems, via a specific direct method. For this method the control function is represented by a finite number of conveniently chosen functions. In this work an example of a linear diffusion system with boundary control is considered, which is worked out entirely, including numerical results. Proper proof are given for the consistency, stability, and convergence of the numerical solution by that direct method. Also, a procedure is indicated for estimating the approximation error in the computed optimal control.
TL;DR: In this paper, a new spot test for urea is described, based on reaction with chloranil, in aqueous solutions, to give a violet color due to the formation of 2,5-dichloro-3-amino-6-hydroxy-p-benzoquinone.
TL;DR: Total proteins and amino-acids are determined in the serum and placenta of mild and severe pre-eclamptic patients as compared to normal pregnant women, and Glycine, tyrosinc, serine, and methionine decreased in both serum and Placenta, whereas glutamic add increased in both.
TL;DR: In this paper, the entropy of water and nitrogen adsorption on hardened cement pastes of various pore structures was computed, and the results were related to the pore structure of the various pastes.