379 research outputs found

    Functional equation of a special Dirichlet series

    Get PDF
    In this paper we study the special Dirichlet series L(s)=23∑n=1∞sin(2πn3)n−s,  s∈C This series converges uniformly in the half-plane Re(s)>1 and thus represents a holomorphic function there. We show that the function L can be extended to a holomorphic function in the whole complex-plane. The values of the function L at the points 0,±1,−2,±3,−4,±5,… are obtained. The values at the positive integers 1,3,5,… are determined by means of a functional equation satisfied by L

    EC-FORC: A New Cyclic Voltammetry Based Method for Examining Phase Transitions and Predicting Equilibrium

    Full text link
    We propose a new, cyclic-voltammetry based experimental technique that can not only differentiate between discontinuous and continuous phase transitions in an adsorbate layer, but also quite accurately recover equilibrium behavior from dynamic analysis of systems with a continuous phase transition. The Electrochemical first-order reversal curve (EC-FORC) diagram for a discontinuous phase transition (nucleation and growth), such as occurs in underpotential deposition, is characterized by a negative region, while such a region does not exist for a continuous phase transition, such as occurs in the electrosorption of Br on Ag(100). Moreover, for systems with a continuous phase transition, the minima of the individual EC-FORCs trace the equilibrium curve, even at very high scan rates. Since obtaining experimental data for the EC-FORC method would require only a simple reprogramming of the potentiostat used in conventional cyclic-voltammetry experiments, we believe that this method has significant potential for easy, rapid, in-situ analysis of systems undergoing electrochemical deposition.Comment: 8 pages, 4 figures, 211th ECS Meetin

    STEROLS BIOACTIVITY OF RUTA GRAVEOLENS L. AND MURRAYA PANICULATA L.

    Get PDF
    Objective: Ruta graveolens L. (R. graveolens) and Murraya paniculata L. (M. paniculata) are medicinal plants belonging to Rutaceae family have many uses in traditional medicine. The aim of the present study was to investigate sterols bioactivity of the two Rutaceae plant leaves.Methods: Sterols of the two Rutaceae plant leaves were identified using GC/MS. The antioxidant activities of the sterols of these herbs were evaluated by three different methods; free radical scavenging using 2,2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) and total antioxidant activity. The anticancer activity of the sterols was determined by MTT assay against colorectal cancer HCT116, breast cancer MCF7, liver cancer HepG2 and lung cancer A549 cell lines. Anti-inflammatory activity was evaluated using albumin denaturation assay and antiviral activities against H5N1 virus were carried out using plaque reduction assay.Results: GC/MS assay showed β-Sitosterol (36%) as the most abundant sterols of R. graveolens followed by stigmasterol (18%), while stigmasterol (25.2%) was the most abundant one of M. paniculata steroids. The anti-inflammatory potential of R. graveolens steroids was significantly higher than that of diclofenac sodium (standard drug). M. paniculata sterols have higher antiviral activity (IC50= 0.15 of µg/ml) than R. graveolens sterols (IC50= 7.8 of µg/ml). The sterols of R. graveolens showed anticancer activity against MCF7 and A549 cells with inhibition 84.3 and 81%, at 100 µg/ml respectively. While M. paniculata sterols showed 77.3% inhibition against A549 cells.Conclusion: The current study suggests that the sterols of M. paniculata have more anti-viral activity than R. graveolens sterols which showed more anticancer and anti-inflammatory activities

    EFFECT OF NITROGEN FERTIGATION LEVELS AND CHELATED CAL-CIUM FOLIAR APPLICATION ON THE PRODUCTIVITY OF SWEET CORN

    Get PDF
    This study was conducted in a sandy soil at Ali Mubarak Village Research Farm, South Tahrir Horticulture Research Station, Behaira Gover-norate, during the two successive seasons of 2002/2003 and 2003/2004 on sweet corn Jubilee hybrid. The study aimed to determine the best treatments of nitrogen fertigation level and chelat-ed calcium foliar application on the productivity and quality of sweet corn. The obtained results indicated that increasing nitrogen fertigation level (100, 120, 140 to 160) kg N/fed. and (or) chelated calcium (12% Ca++) concentration (500 and 1000 ppm Ca EDTA) led to increasing the vegetative growth (leaf area, plant height, fresh and dry weight), chemical composition (total chlorophyll, nitrogen, phosphorus, potassium and calcium in leaves) and yield characters (ear length, ear diame-ter, weight of 1000 seed, unhusked ear, husked ear and total yield) The promising treatment was 160 kg N/Fed. combined with 1000 ppm Ca EDTA under similar prevailing conditions of the present studying in a sandy soi

    Biotransformation of furanocoumarins by Cunninghamella elegans

    Get PDF
    AbstractBiotransformation of Furanocoumarins; psoralen (1), bergapten (2), xanthotoxin (3) and imperatorin (4) was explored by Cunninghamella elegans NRRL 1392, revealing the metabolism of psoralen (1) and bergapten (2) into bergaptol (5), while xanthotoxin (3) and imperatorin (4) were converted into xanthotoxol (6). On the other hand unexpected conversion of xanthotoxin (3) into 3,4 dihydroxanthotoxin (7) occurred. The structure of the isolated pure metabolites was established using physical and spectroscopic techniques including, melting points, IR, 1H NMR, 13C NMR and mass spectroscopy

    EFFECT OF SALINE WATER IRRIGATION AND FOLIAR SPRAYING OF SALICYLIC ACID ON GROWTH, FLOWERING AND CHEMICAL COMPOSITION OF POT MARIGOLD (Calendula officinalis L.) PLANT

    Get PDF
    This study was carried out to investigate the effect of saline water irrigation at 2000, 4000, 6000, 8000 and 10000 ppm by using a mixture of two salts (sodium chloride: calcium chloride, 2:1, w/w)  in addition to tap water  as control and foliar sprayings of Salicylic acid (SA) at 100, 200 and 300 ppm in addition to tap water as control on growth, flowering and chemical composition of pot marigold plants in the two successive seasons of 2014/2015 and 2015/2016 in the Faculty of Agriculture, Ain Shams University, Qalyubia Governorate, Egypt. Results revealed that all tested foliar applications of SA increased all vegetative growth characteristics (plant height, number of leaves /plant, leaf area, number of branches/plant, diameter of stem, fresh and dry weights of vegetative growth and roots, and roots volume), and flowering attributes (number of inflorescences/plant, diameter of inflorescence, fresh and dry weights of inflorescences). While, saline water irrigation decreased growth, flowering parameters, chlorophyll, carotene contents in flowers and some minerals contents of the vegetative growth, i.e. nitrogen, phosphorus and potassium percentages. However, saline water irrigation increased proline and some mineral contents, i.e. calcium, sodium and chloride percentages of the vegetative growth. In most cases, under the same saline water irrigation conditions spraying SA at 100 and 200 ppm concentrations alleviated the salinity effect on the plants, enhanced the plant growth and increased the flowering parameters. The most effective treatments which enhance growth, flowering parameters, chlorophyll content, carotene contents in flowers, proline and mineral contents were found to be 100 and 200 ppm SA spraying under nonsaline conditions

    A new battery-charging method suggested by molecular dynamics simulations

    Full text link
    Based on large-scale molecular dynamics simulations, we propose a new charging method that should be capable of charging a Lithium-ion battery in a fraction of the time needed when using traditional methods. This charging method uses an additional applied oscillatory electric field. Our simulation results show that this charging method offers a great reduction in the average intercalation time for Li+ ions, which dominates the charging time. The oscillating field not only increases the diffusion rate of Li+ ions in the electrolyte but, more importantly, also enhances intercalation by lowering the corresponding overall energy barrier.Comment: 11 pages, 5 figure

    Demineralization-remineralization dynamics in teeth and bone

    Get PDF
    Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide

    Diagnose Digital Skills Gap between Professional and Academic Sectors in Architecture Discipline – Jordan Case Study

    Get PDF
    There are many studies on digitization. The newly graduated engineer has a way of thinking, currency, and outlook on engineering work. Research on the ability of universities to graduate qualified architects for the professional market has become necessary to bring about changes in teaching methods and link them to digital programs. This paper looks at if there is a consensus between the opinion of professionals and academics about digital skills, trying to integrate urgent digital skills needed by the labor market in the Architecture education study plans. Mixed between quantitative and qualitative research methods, researchers analyze the study plan of 12 universities, using the Curriculum Content Mapping )CMM( method, and conduct a questionnaire for academics and professionals. Accordingly, we prove the gap between the profession and the academic world in the discipline, and there is no agreement between them about the digital programs needed. Then researchers provide a matrix expressing the relationship between the digital courses and the AE courses in a way to connect the two
    • …
    corecore