1,096 research outputs found

    Auger Spectra and Different Ionic Charges Following 3s, 3p and 3d Sub-Shells Photoionization of Kr Atoms

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    The decay of inner-shell vacancy in an atom through radiative and non-radiative transitions leads to final charged ions. The de-excitation decay of 3s, 3p and 3d vacancies in Kr atoms are calculated using Monte-Carlo simulation method. The vacancy cascade pathway resulted from the de-excitation decay of deep core hole in 3s subshell in Kr atoms is discussed. The generation of spectator vacancies during the vacancy cascade development gives rise to Auger satellite spectra. The last transitions of the de-excitation decay of 3s, 3p and 3d holes lead to specific charged ions. Dirac-Fock-Slater wave functions are adapted to calculate radiative and non-radiative transition probabilities. The intensity of Kr^{4+} ions are high for 3s hole state, whereas Kr^{3+} and Kr^{2+} ions have highest intensities for 3p and 3d hole states, respectively. The present results of ion charge state distributions agree well with the experimental data.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

    Use of remote sensing and GIS in mapping the environmental sensitivity areas for desertification of Egyptian territory

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    International audienceDesertification is defined in the first art of the convention to combat desertification as "land degradation in arid, semiarid and dry sub-humid areas resulting from climatic variations and human activities". Its consequence include a set of important processes which are active in arid and semi arid environment, where water is the main limiting factor of land use performance in such ecosystem . Desertification indicators or the groups of associated indicators should be focused on a single process. They should be based on available reliable information sources, including remotely sensed images, topographic data (maps or DEM'S), climate, soils and geological data. The current work aims to map the Environmental Sensitivity Areas (ESA's) to desertification in whole territory of Egypt at a scale of 1:1 000 000. ETM satellite images, geologic and soil maps were used as main sources for calculating the index of Environmental Sensitivity Areas (ESAI) for desertification. The algorism is adopted from MEDALLUS methodology as follows; ESAI = (SQI * CQI * VQI)1/3 Where SQI is the soil quality index, CQI is the climate quality index and VQI is the vegetation quality index. The SQI is based on rating the parent material, slope, soil texture, and soil depth. The VQI is computed on bases of rating three categories (i.e. erosion protection, drought resistance and plant cover). The CQI is based on the aridity index, derived from values of annual rainfall and potential evapotranspiration. Arc-GIS 9 software was used for the computation and sensitivity maps production. The results show that the soil of the Nile Valley are characterized by a moderate SQI, however the those in the interference zone are low soil quality indexed. The dense vegetation of the valley has raised its VQI to be good, however coastal areas are average and interference zones are low. The maps of ESA's for desertification show that 86.1% of Egyptian territory is classified as very sensitive areas, while 4.3% as Moderately sensitive, and 9.6% as sensitive. It can be concluded that implementing the maps of sensitivity to desertification is rather useful in the arid and semi arid areas as they give more likely quantitative trend for frequency of sensitive areas. The integration of different factors contributing to desertification sensitivity may lead to plan a successful combating. The usage of space data and GIS proved to be suitable tools to rely estimation and to fulfill the needed large computational requirements. They are also useful in visualizing the sensitivity situation of different desertification parameters

    A Conceptual Model to Measure ERP User-Value

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    The critical factors in the onward and upward phase that maximize the value o the enterprise resource planning (ERP) system from the user’s point of view remain unidentified. A recent study of a public sector organization in the state of Colorado showed that the users’ perspectives regarding the benefits of an ERP system are unrecognized, as well as how the users of the ERP system view the ERP benefits post-implementation. The purpose of this study is to determine the factors that maximize the value of the implemented ERP system in the onward and upward phase postimplementation from the user’s point of view (ERP user value), and how these factors affect the ERP user productivity, effectiveness, and internal efficiency which are major issues for management. A proposed conceptual structural model, based on the Technology-Organization-Environment (TOE) framework, is presented. It is posited that the conceptual model can be used to predict the post-implementation factors from the ERP user’s point of view and measure their impact on the overall ERP benefits for the organization. The research question, hypotheses, and current state of research are presented and discussed

    The value of Holter monitoring in the assessment of Pediatric patients

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    Aims: Holter monitoring (HM) has been established as one of the most effective noninvasive clinical tools in the diagnosis, assessment and risk stratification of cardiac patients. However, studies in the pediatric age group are limited. The present work aims at determining the value of HM in the diagnosis and management of children. Settings and Design: Retrospective study conducted at a tertiary referral arrhythmolology service.Methods and Material: Holter records of 1319 pediatric patients (54.1% males and 45.9% females) were reviewed. Their average age was 6.7± 4.1 years (5 days-16 years). Indications for which Holter monitoring was done were analysed as well as all the abnormalities diagnosed and factors that may increase Holter yield.Statistical analysis used: Statistical Package of social science (SPSS) version 9,0 was used for analysis of data. Results: The most common indications were palpitations (19.8%), syncope (17.8%), cardiomyopathy (12.6%), chest pain (10%), evaluation of antiarrhythmic therapy (6.8%), postoperative assessment (2.6%) and complete AV Block (2.4%). A sum of 141 Holter recordings were found abnormal with a total diagnostic yield of 10.7%. The highest contribution to diagnosis was in postoperative assessment (32.4%) and in cardiomyopathy (19.9%) where the most common abnormalities were frequent supraventricular / ventricular premature beats, supraventricular tachycardia, ventricular tachycardia and AV block. Diagnostic yield was low in patients with palpitations (5.7%) and syncope (0.4%). An abnormal ECG was significantly associated with a higher diagnostic yield (p=0.0001). None of the children with chest pain had abnormal Holter recordings.Conclusions: HM has an extremely valuable role in the assessment of high risk patients (postoperative and cardiomyopathy). However in children with palpitations, syncope and chest pain HM has a low yield. In this group of patients an abnormal ECG is more likely to be associated with abnormal Holter recordings


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    This paper presents the shear behavior of lightweight self-consolidating concrete (LWSCC) beams without shear reinforcement compared to those made with normal weight self-consolidating concrete (SCC). The variables in this experimental and Code based study was shear span to depth ratio, concrete types and longitudinal reinforcement. The performance of LWSCC was compared with normal SCC beams based on load-deformation response, stress-strain development, and shear strength and failure modes. LWSCC beams showed lower post-cracking shear resistance and the shear strength of LWSCC/SCC beams increased with the decrease of shear span to depth ratio. LWSCC beams showed higher number of cracks and wider crack width at failure than their SCC counterparts. American, Canadian and British Codes were conservative in predicting shear strength of LWSCC beams

    Review of Recommender Systems Algorithms Utilized in Social Networks based e-Learning Systems & Neutrosophic System

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    In this paper, we present a review of different recommender system algorithms that are utilized in social networks based e-Learning systems. Future research will include our proposed our e-Learning system that utilizes Recommender System and Social Network. Since the world is full of indeterminacy, the neutrosophics found their place into contemporary research. The fundamental concepts of neutrosophic set, introduced by Smarandache in [21, 22, 23] and Salama et al. in [24-66].The purpose of this paper is to utilize a neutrosophic set to analyze social networks data conducted through learning activities

    Cellulose Ether-Based Liquid Crystal Materials: Review Article

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    The development of liquid crystal materials via nanotechnology has become an interesting subject of research in optical material chemistry. One of the significant nanomaterials is cellulose-based nanoparticles. In this review article, we highlighted the classification of liquid crystal materials (LCs), and types of cellulose-NPs and their characterization as LCs materials. Finally, we present our promising data on the synergistic effect of cellulose-NPs on liquid crystal behavior of ethyl cellulose- and hydroxypropyl cellulose- nanocomposites

    Ultrasound-Guided Pectoral Nerves Block Type II or Intercostobrachial Nerve Block as A Supplement to Supraclavicular Block in End-Stage Renal Disease Patients’ Arteriovenous Access: A Randomized Controlled Trial

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    Background: Intercostobrachial nerve (ICBN) innervates the upper half of the medial aspect of the arm and axilla. We hypothesized to assessing either pectoral nerves block type II (PECS II) or ICBN block would improve the quality of block for proximal arm arteriovenous access surgery. Materials and Methods: In the study, forty adult patients with the end-stage renal disease aged between 18 and 70 years received a combined supraclavicular block with 30 ml 0.25% bupivacaine, and either ICBN (Group A, n = 20) or PECS II block with 10 ml 0.25% bupivacaine (Group B, n = 20) for proximal arm arteriovenous access surgery. The primary outcome was whether patients required intraoperative local anesthetic supplementation. Secondary outcomes were the volume of local anesthetic supplementation, fentanyl administration, Pain scores 24 hours postoperatively, and time to first postoperative rescue analgesia. Results: Local anesthetic (LA) supplementation was required in 4 patients in group A and 6 patients in group B, and the mean volume of LA was lower in group A than group B as the complete sensory block in the medial side of the upper arm was achieved in 80% of patients in group A and 70 % in group B. There was a statistically significant decrease in time taken for blocks in group B (PECS) compared to group A and, the insignificant difference between the two studied groups regarding fentanyl received and time to 1st postoperative rescue analgesia. Conclusion: ICBN and PECS blocks are ideal supplements to supraclavicular brachial (SCB) with statistically insignificant fewer patients in ICBN required LA volume and supplementation than PECS II block