926 research outputs found

    Associated Matrix Polynomials with the Second Kind Chebyshev Matrix Polynomials

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    This paper deals with the study of the associated Chebyshev matrix polynomials. Associated matrix polynomials with the Chebyshev matrix polynomials are defined here. Some properties of the associated Chebyshev matrix polynomials are obtained here. Further, we prove that the associated Chebyshev matrix polynomials satisfy a matrix differential equation of the second order

    On Hermite-Hermite matrix polynomials

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    summary:In this paper the definition of Hermite-Hermite matrix polynomials is introduced starting from the Hermite matrix polynomials. An explicit representation, a matrix recurrence relation for the Hermite-Hermite matrix polynomials are given and differential equations satisfied by them is presented. A new expansion of the matrix exponential for a wide class of matrices in terms of Hermite-Hermite matrix polynomials is proposed

    SAFE CONTROL OF SOIL BORNE PATHOGENS OF BELL PEPPER PLANTS UNDER PLASTIC-HOUSE CONDITIONS

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    The experiments were conducted at the farm of Al-Alamia located at Nubaria- Egypt, in plastic houses (6m x 45m) where solanaceous crops have been grown as monoculture, and aimed to evaluate the soil solarization in combination with benefit microorganisms for controlling the pepper soil borne pathogens and weeds under plastic-house condition. Supplementation of organic matter in plastic-houses resulted in noticeable increase in fungal, bacterial and nematode counts. However, the population densities of total fungi,Fusaria, total bacteria, spore former bacteria, actinomycetes and nematodes after 15 and 30 days in the solarized plastic-houses were drastically reduced as compared tonon solarized control soil. This reduction was gradually increased depended on the time of sampling (after 15 days of transparent polyethylene mulching or after 30 days). Soil solarization reduced sharply free nitrogen fixers, 30 days after treatment the elimination of the Azotobacter spp. and Azospirillum spp. from soil was recorded. However, the free nitrogen fixers were found to be recolonized after one month from transplanting the seedling pepper plants in non solarized and solarized soil, so artificial inoculation of pepper seedlings with strains of Azotobacter sp. and Azospirillum sp., were resulted great root colonization of plants than in non-solarized soil. Also, all annual weeds have been controlled with soil solarization which gave the best weed control treatment. On the other hand, solarization had pronounced effect on seedling establishment occurred in solarized plastic-houses. Increasing more than 30% in establishment of pepper seedling were recorded between the solarized and non-solarized plastic-houses which mulched with black sheets after three weeks of pepper transplanting.  The percentage of Phytophthora spp. isolated from the infected pepper seedlings were very high compared with other fungi, it was 49% of total isolated fungi after one week of transplanting. However, soil solarization increased pepper plant height and number of branches per plant as compared with non-solarized soil without black mulching or with black mulching. The pepper yield per plastic house up to 7 months increased with soil solarization by about 216 Kg, 18.3% over non solarized with black mulching, and 155 Kg, 12.4% over non solarized without mulching

    ISOLATION, SCREENING AND IDENTIFICATION OF PROMISING YEAST ISOLATES USED FOR BIOLOGICAL CONTROL OF ORANGE GREEN MOULD

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    Ninety nine yeast isolates were isolated from surface of apple, grape, orange and tomato fruits. The isolates were tested in vivo in preliminary study for biocontrol potential against green mould of navel orange fruit. According to primary screening, twenty two isolates were selected to continue the secondary screening (phase one) using different concentrations of the washed yeast cells in water suspension to evaluate their biocontrol efficacy at 21±1°C. Among twelve yeast isolates were passed to the secondary screening (phase two) at 7±1°C, washed cells of yeast isolates CT 503, CT 507, CT 508, CT 512 and CT 550 at 1x109, 2x108 and 1x108 CFU/ml produced complete protection for 21 days to wounded navel orange fruits inoculated with spore suspension of Penicillium degitatum  (1x104 conidia /ml).  Meantime, no lesions developed on the navel orange fruits treated with the yeast isolates CT 503, CT 507 (Debaryomyces hansenii var. hansenii strain C) and CT 512 (Endomycopsella vivi) at 6.6x107CFU/ml, while the percentage of rot reduction of the isolate CT 550 (Candida edax) was 99.81%. Culture filtrate of twenty two different yeast isolates used in secondary screening (phase one) did not prevent decay of wounded navel orange fruits but had an inhibitory effect on rot development. The relative abilities of the promising yeast isolates (CT 503, CT 507, CT 512 and CT 550) to induce disease resistance against P. digitatum on navel orange fruits were studied. Inoculation of promising yeast isolates significantly triggered induction of resistance in navel orange fruits. The lesion diameters of green mould 66 hours later after inoculation by spore suspension of P. digitatum  in a neighbouring wound that was made approximately 6 mm away from the initial woundwhich inoculated withthe isolates CT 512, CT 550, CT 507 and CT 503 were reduced by 25.5%, 20.5%, 16.7% and 14.1%, respectively. In this respect, there were no significant differences among the three different isolates CT 503, CT 507 and CT 550

    SYNTHESIS AND EVALUATION OF ETHYL (4-(N-(THIAZOL-2-YL) SULFAMOYL) PHENYL)CARBAMATE (TSPC) AS A CORROSION INHIBITOR FOR MILD STEEL IN 0.1M HCL

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    Laboratory synthesized ethyl (4-(N-(thiazol-2-yl)sulfamoyl)phenyl)carbamate (TSPC), characterized by 1H NMR spectroscopy, was evaluated as corrosion inhibitor of mild steel in 0.1M HCl using electrochemical techniques. Open circuit potential, potentiodynamic polarization and impedance spectroscopy were used to evaluate the inhibition efficiency of (TSPC) at various concentrations. The obtained electrochemical data indicated that (TSPC) acts as moderate corrosion inhibitor for mild steel in acidic media. It is found that the inhibition efficiency increases with the concentration of the inhibitor till 400ppm. The adsorption isotherm involving physisorption of (TSPC) at room temperature and the experimental data complied to the Langmuir adsorption isotherms and the negative values of the Gibb’s free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface

    Translating the Concept of Goal Setting into Practice -- What 'Else' does it Require than a Goal Setting Tool?

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    This conceptual paper reviews the current status of goal setting in the area of technology enhanced learning and education. Besides a brief literature review, three current projects on goal setting are discussed. The paper shows that the main barriers for goal setting applications in education are not related to the technology, the available data or analytical methods, but rather the human factor. The most important bottlenecks are the lack of students goal setting skills and abilities, and the current curriculum design, which, especially in the observed higher education institutions, provides little support for goal setting interventions.Comment: This paper has been accepted to be published in the proceedings of CSEDU 2020 by SciTePres

    Nile perch fish nuggets: Partial replacement of fish flesh with sesame hulls and sunroot — Quality assessment and storage stability

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    This study aimed to produce Nile perch fish nuggets by replacing a part of fish flesh with different concentrations of sesame hulls and sunroot to reach the optimal recipe. Chemical, microbiological, and sensory characteristics of nuggets were evaluated during 3 months of frozen storage at –18 °C. According to the obtained data on the chemical composition of raw materials, Nile perch flesh had the highest content of protein (20.21%), sesame hulls contained the highest amount of fat (13.54%), fiber (17.24%) and ash (16.11%), while sunroot tubers had the highest amount of carbohydrates (15.76%). Based on the sensory score, the acceptable replacement ratio for fish nuggets prepared with sunroot (T1) and sesame hulls (T2) was 10% and 7.5%, respectively. Thiobarbituric acid (TBA) analysis at zero time shows that the T1 samples had the minimum value compared to the T2 and control samples. During storage, the TBA levels increased slightly in all samples, but after three months T1 also showed the lowest value. The total plate count (TPC) and psychrophilic bacterial (PSY) count in the samples were affected by the period of frozen storage at –18 °C. The initial TPC and PSY loads were 2.32 and 2.02 log cfu/g for control; 2.24 and 1.72 log cfu/g for T1; 2.30 and 1.47 log cfu/g for T2, respectively. During storage, the values of TPC and Psy slightly decreased. In conclusion, this study succeeded in the replacement of Nile perch fish with sesame hulls and sunroot as new sources to improve the nutritional value and quality characteristics of fish nuggets.This study aimed to produce Nile perch fish nuggets by replacing a part of fish flesh with different concentrations of sesame hulls and sunroot to reach the optimal recipe. Chemical, microbiological, and sensory characteristics of nuggets were evaluated during 3 months of frozen storage at –18 °C. According to the obtained data on the chemical composition of raw materials, Nile perch flesh had the highest content of protein (20.21%), sesame hulls contained the highest amount of fat (13.54%), fiber (17.24%) and ash (16.11%), while sunroot tubers had the highest amount of carbohydrates (15.76%). Based on the sensory score, the acceptable replacement ratio for fish nuggets prepared with sunroot (T1) and sesame hulls (T2) was 10% and 7.5%, respectively. Thiobarbituric acid (TBA) analysis at zero time shows that the T1 samples had the minimum value compared to the T2 and control samples. During storage, the TBA levels increased slightly in all samples, but after three months T1 also showed the lowest value. The total plate count (TPC) and psychrophilic bacterial (PSY) count in the samples were affected by the period of frozen storage at –18 °C. The initial TPC and PSY loads were 2.32 and 2.02 log cfu/g for control; 2.24 and 1.72 log cfu/g for T1; 2.30 and 1.47 log cfu/g for T2, respectively. During storage, the values of TPC and Psy slightly decreased. In conclusion, this study succeeded in the replacement of Nile perch fish with sesame hulls and sunroot as new sources to improve the nutritional value and quality characteristics of fish nuggets

    First Report of Leishmania tropica from a Classical Focus of L. major in North-Sinai, Egypt

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    This is the publisher's version, also available electronically from http://www.ajtmh.org/content/81/2/213.long.Cutaneous leishmaniasis (CL) is prevalent in the Egyptian Sinai Peninsula and previous research has consistently documented the etiologic agent to be Leishmania major. We report the first isolation of Leishmania tropica from human cases of CL in a Northern Sinai community bordering Palestine. Parasite culturing, real-time polymerase chain reaction (PCR), gene sequencing, and restriction fragment length polymorphism (RFLP) analyses indicate CL cases in this community were caused by either L. major or L. tropica (three cases each). Two wild-caught rodents (Gerbillus pyramidum floweri) were infected with L. tropica. Phlebotomus papatasi sand flies were found harboring L. major, however only non-infected individuals of Phlebotomus sergenti, a vector for L. tropica, were caught. Patients with L. tropica had not traveled from the region in over a year, suggesting these cases are autochthonous. This scenario is consistent with an incursion of L. tropica from bordering countries and raises concerns about expansion of this parasite further into Egypt

    Small bowel perforation by a piece of china with a synchronous asymptomatic sigmoid carcinoma: A case report

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    A 75 year old gentleman who presented with an incarcerated paraumibilical hernia was found intraoperatively to have small bowel perforation due to a piece of china with a synchronous asymptomatic sigmoid carcinoma
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