539 research outputs found

    MIMO Beamforming Network Having Polarization Diversity

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    Comparative study ofthe computational fluid dynamics and fluid structure interaction analysis in human airways flow

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    Numerous studies have been done in order to get the most accurate result that represents the flow characteristics inside the human trachea. Numerical method was the most favorite type of study chosen to simulate the model due to the complexity of the geometry and difficulties to get the real trachea to do the experimental works. In this study, one actual healthy model of human trachea was reconstructed in order to compare, the different of the velocity and pressure distribution between two types of numerical modeling analysis: Computational Fluid Dynamics (CFD) and Fluid Structure Interaction (FSI) analysis. The model was extracted using the Computed Tomography (CT) scan images to maintain the realistic geometry. Velocity, 1.24 m/s was used at the inlet and the variations of the velocity and pressure distribution along the trachea were observed. The results shown that, the implementation of the FSI technique did produce different result and flexibility of the structure wall did influence the distribution of the velocity and pressure along the trachea

    Behavior of biodegradable oil under impulse voltages

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    The properties of Palm Oil (PO) and Coconut Oil (CO) offer the potential for transformers with non-toxicity, high fire and flash points and better environmental compatibility while compared with those filled with Mineral Oil (MO). This potential has led to intensive studies of electrical performance of biodegradable oil especially in evaluating the electrical performance under lightning impulse voltage in recent years. This paper presents the investigation on the impulse breakdown voltage of PO and CO in such a uniform field. The PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein type. Two testing methods, rising-voltage and up-and-down are considered for both oils with different gap distances (2.0 mm and 3.8 mm). Testing methods including rising-voltage method and up-and-down method have no notable influence on the breakdown voltages of RBDPOs and CO compared to MO.IntroductionThe majority of transformers in the power system network are oil filled type. The main functions of the oil used in a transformer are to act as electrical insulation, cooling medium and information carrier. Up to now, the main oil insulation used in a transformer is Mineral Oil (MO) since it is proven to be successfully applied in practice for many years. Natural and synthetic esters are considered as the alternative for conventional MO due to the high fire safety and environmental friendliness. Extensive studies were conducted looking into the chemical, physical and electrical properties of natural and synthetic esters [1-3]. Another possible alternative for ester based oils are Palm Oil (PO) and Coconut Oil (CO). PO is derived from palm kernel which can be further separated to produce Crude Palm Oil (CPO) and Crude Palm Kernel Oil (CPKO) [4-5]. Further processing of CPO can produced Refined, Bleaching and Deodorized Palm Oil (RBDPO). The most common PO considered for transformers application is RBDPO. On the other hand, CO is extracted from kernel of matured coconut palm. The CO can be further processed to produce a neutralized, bleached and deodorized CO and is currently the type of oil investigated for the transformers’ application [6]. Transformer in service shall be exposed to voltages in excess of the normal operating voltage, such as transient overvoltage due to lightning impulse or switching impulse. Therefore the increasing interests among researchers press for comprehensive investigations on electrical performance of these liquids especially under impulse voltage [7]. This paper presents breakdown strengths of biodegradable oils (RBDPOs and CO) and MO in a uniform sphere-sphere electrode under impulse voltages. The influences of voltage polarities (positive and negative) and testing methods (rising-voltage and up-and-down) on the breakdown behavior are investigated

    Standard time of import paperwork clearance department for sustainability organization performance in forwarding company

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    In order to achieve sustainable performance, it was emphasized for an organization for improvement of the standard performance. This paper attempts to propose a benchmark for the standard time to complete daily paperwork received at a forwarding company by using the define-measure-analyse-improve-control (DMAIC) approach. Results showed that the import clearance agent required 3 days or more to clear paperwork for duty or tax confirmation. The impact led to delayed shipment delivery, caused by customer dissatisfaction and company loss of trusts amongst customers. It was also found that that the number of paperwork received daily was 516, distributed among an average of 15 employees, from January to April 2018. Each employee received an average of 34 paperwork daily. The amount of paperwork received by each employee was at alarming level. The time required to complete paperwork for duty/tax confirmation were 3 days or more for most of the employees, which stood at 62%. Therefore, based on the results of the findings, the proposed benchmark of the standard time for paperwork clearance should not be more than 1 day to allow for same day delivery to the customers, as per the commitment promised by the company

    Evaluation of electromagnetics radiation for stroke patients and non-stroke participants according to body segmentation

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    This research evaluates the electromagnetic radiation (EMR) for the stroke patients and non-stroke patients according to body segmentation. The human body is divided into three segments: top, middle and bottom. The frequency in hertz is collected at 23 points around the human body namely left side, right side and chakra points from 199 subjects undergoing post-stroke treatment and 100 non-stroke participants. The EMR is captured using frequency detector equipped with a dipole antenna. The data is collected by taking the reading of the frequency 5 times at each point at the same location; hence, the average value is calculated. The statistical analysis of the EMR are examined using SPSS software and Microsoft excel is used to calculate the average frequency of the data. In conclusion, the findings significantly shows that stroke patients has lower frequency value of EMR for both right side and left side but has higher frequency for chakra system. This is true for all the three segments of the body. Furthermore, it is also shown that there is no correlation between the left and the right side frequency for the stroke patients whereas the left-right correlation values are significantly high for the non-stroke participants. This observation justify that EMR from human body can contribute to early detection for stroke

    Analisis Difusi Larutan Pupuk Melalui Dinding Mortar Arang Sekam Padi

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    The aim of this reasearch is to determine difussion coefficient of nutrient solution through rice husk charcoalmortar walls. This research used completely randomized design (CR) with factorial arrngement which consistedof factors. The first factor, the material composition ratios of mortars (cement : sand : rice husk charcoal),consisted of two levels: P 1 (1:3:3) and P 2 (1:3:4). The second factor, the concentration of nutrient consisted ofree levels, namely K 1 (3 mS/cm), K 2 (6 mS/cm), and K 3 (9 mS/cm). Data set was analyzed by using ANOVA,then followed by using LSD at 5% significant level. Anova showed that there was interaction between mortarmaterial composition and nutrient concentration. The best diffusion coefficient was found in the treatment P 2 K 1and P 2 K 2 (1:3:4 and the nutrient concentrations 3 mS/cm, 6 mS/cm). Nutrient solution in the treatments couldpass through the walls of mortar very well, so that it could be used as a means of fertigation

    Kafa travmasında kafa içi basınç ve hipotalamo-hipofizer- gonadal aks arasındaki ilişkinin değerlendirilmesi

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    Objective: Head traumas have an important place among all traumatic injuries and it is an important public health problem worldwide. Novel methods predicting prognosis may contribute to a decrease in the mortality and morbidity rates.Materials and Methods: Continuous intracranial pressure '(ICP) measurements, initial cerebral computed tomography '(CT) and measurement of the hypothalamicpituitary- gonadal '(HPG) axis hormones between the 0th and 4th days were performed in 15 adult male patients with severe head trauma. The relationship of these parameters with the short-term results of the patients on the 15th day was evaluated. Additionally, provocation tests were carried out to evaluate the HPG axis function.Results: High ICP and compression of basal cisterna increased mortality and they were found to affect prognosis `(p=0.009 and p=0.033, respectively) No statistically significant association was found between midline shift and prognosis. No relationship was found between mortality and mean basal hormone values on the 0th day and between the 1st and 4th days.Conclusion: ICP measurement values and the presence of compression of basal cistern on the initial brain CT can be used to predict the prognosis in severe head injury but there is no significant relationship between hypophyseal hormone values and prognosis

    Factors Affecting Current Ratings for Underground and Air Cables

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    The aim of this paper is to present a parametric study to determine the major factors that influence the calculations of current rating for both air and underground cables. The current carrying capability of the power cables rely largely on the installation conditions and material properties. In this work, the influences on ampacity of conductor size, soil thermal resistivity and ambient soil temperature for underground installations are shown. The influences on the current-carrying capacity of solar heating (time of day effects and intensity of solar radiation), ambient air temperature and cable size for cables air are also presented. IEC and IEEE standards are taken as reference

    A state-of-the-art study of cloud manufacturing

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    There is a considerable industrial standard transfer. This will drive to the adaptable usage of various globally shared, emerging within the manufacturing field by Combining advanced manufacturing models such as the Internet of things, cloud computing, service-oriented technologies, big data, and recently Cloud Manufacturing. Cloud manufacturing a program is a combined program that empowers manufacturers to distribute sources contribute manufacturing services and including supports compatible cooperation. Economically significantources, such as the manufacture of software tools, importance, knowledge, and manufacturing capacity, and material, then become available to supposed users on a global basis, the principal benefits and difficulties of achieving cloud manufacturing are analyzed. the key New technologies for manufacturing model, is cloud manufacturing, cloud manufacturing aims to achieve full participation, free of charge, And easy for utilization of various sources and manufacturing abilities in the form of manufacturing setting. This paper contributes an overview of the cloud manufacturing
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