2,364 research outputs found

    A comparative Performance Analysis of 4x4 MIMO-OFDM system using Spatial Multiplexing under various Wireless Channels

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    Multiple Input Multiple Output (MIMO) technology refers to wireless communication systems employing multiple antennas at either the transmitter end or the receiver end or both. In recent times, use of multiple transmit and receive antenna for enhancing spectral efficiency in a wireless system has established much interest in research field. The solution to obtain superior data rates and better range performance at the same time is OFDM integrated with MIMO technique which is based on IEEE 802.11n standard. The main trouble in front of the wireless multipath propagation is the interference between information symbols transmitted through neighbouring channels also called as Inter Symbol Interference (ISI). This could be avoided if we use OFDM technology. Thus MIMO combined with OFDM has got significant importance in future wireless communication system. The major properties of MIMO system involve Spatial Diversity and Spatial Multiplexing which are the main factors to discuss and matter of concern to achieve reliability and high speed data rate. In this paper, we study the performance gain of MIMO-OFDM systems. The main investigation carried out in the following paper is to deal with various Wireless channel models in Spatial Multiplexing (SM) mode. The paper deals with MIMO-OFDM system analysis in various Wireless channel models (Rayleigh, Rician, Nakagami and 3GPP channel Environment) focusing on error rate performance, throughput and Spectral gain in 4x4 MIMO scheme under OFDM system. Evaluation of Bit Error Rate and throughput with respect to varying Eb/No for 4x4 MIMO-OFDM in Spatial Multiplexing mode, employing 16 QAM modulation with N=128 OFDM subcarriers employing MMSE detection, is the baseline of this paper

    ^25Mg NMR study of the MgB_2 superconductor

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    ^25Mg NMR spectra and nuclear spin-lattice relaxation time, T_1, have been measured in polycrystalline ^25MgB_2 with a superconducting transition temperature T_c = 39.0 K in zero magnetic field. From the first order and second order quadrupole perturbed NMR spectrum a quadrupole coupling frequency nu_Q = 222(1.5) kHz is obtained. T_1T = 1090(50) sK and Knight shift K_c = 242(4) ppm are temperature independent in the normal conducting phase. The ^25Mg Korringa ratio equals to 0.95 which is very close to the ideal value of unity for s-electrons. The comparison of the experimental nu_Q, T_1T, and K_c with the corresponding values obtained by LDA calculations shows an excellent agreement for all three quantities.Comment: 4 pages including 4 eps-figures, revtex

    Formulation and evaluation of thermoreversible mucoadhesive nasal gels of metoclopramide hydrochloride

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    The prolonged residence of drug formulation in the nasal cavity is of utmost importance for intranasal drug delivery. The objective of the present investigation was to develop a mucoadhesive in situ gel with reduced nasal mucocilliary clearance in order to improve the bioavailability of the antiemetic drug, metoclopramide hydrochloride. The in situ gelation upon contact with nasal mucosa was conferred via the use of the thermogelling Pluronic flake 127 (18%). Mucoadhesion was modulated via the use of hydroxy propyl methyl cellulose (HPMC), sodium carboxy methyl cellulose (Na CMC) and sodium alginate (Na-alginate) whereas drug release was modified by varying concentrations of polyethylene glycol 6000 (PEG 6000). The results revealed that the different mucoadhesives increased the gel viscosity but reduced its sol gel transition temperatures. The increase in viscosity was highest in formulations with Na-alginate and lowest in formulations with HPMC. PEG 6000 significantly decreased mucoadhesive strength of formula containing 0.3% HPMC (776.6 ± 19.55 to 713.6 ± 5.03), 0.2% Na CMC (656 ± 11.13 to 575 ± 9.07) and 0.2% Na-alginate (659 ± 11.13 to 618.3 ± 9.45) whereas the gelation temperature increased by 3 to 4 °C. 100% of drug diffusion was found at four hours for formulation F5, F9, and F12. Formulation F5 showed maximum permeability (0.00949 ± 0.00021 mg.cm/min) than other formulation containing PEG6000. This study concluded the potential use of mucoadhesive in situ nasal gel in terms of ease of administration, accuracy of dosing, prolonged nasal residence and improved nasal bioavailability.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Formulation and evaluation of thermoreversible mucoadhesive nasal gels of metoclopramide hydrochloride

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    The prolonged residence of drug formulation in the nasal cavity is of utmost importance for intranasal drug delivery. The objective of the present investigation was to develop a mucoadhesive in situ gel with reduced nasal mucocilliary clearance in order to improve the bioavailability of the antiemetic drug, metoclopramide hydrochloride. The in situ gelation upon contact with nasal mucosa was conferred via the use of the thermogelling Pluronic flake 127 (18%). Mucoadhesion was modulated via the use of hydroxy propyl methyl cellulose (HPMC), sodium carboxy methyl cellulose (Na CMC) and sodium alginate (Na-alginate) whereas drug release was modified by varying concentrations of polyethylene glycol 6000 (PEG 6000). The results revealed that the different mucoadhesives increased the gel viscosity but reduced its sol gel transition temperatures. The increase in viscosity was highest in formulations with Na-alginate and lowest in formulations with HPMC. PEG 6000 significantly decreased mucoadhesive strength of formula containing 0.3% HPMC (776.6 ± 19.55 to 713.6 ± 5.03), 0.2% Na CMC (656 ± 11.13 to 575 ± 9.07) and 0.2% Na-alginate (659 ± 11.13 to 618.3 ± 9.45) whereas the gelation temperature increased by 3 to 4 °C. 100% of drug diffusion was found at four hours for formulation F5, F9, and F12. Formulation F5 showed maximum permeability (0.00949 ± 0.00021 mg.cm/min) than other formulation containing PEG6000. This study concluded the potential use of mucoadhesive in situ nasal gel in terms of ease of administration, accuracy of dosing, prolonged nasal residence and improved nasal bioavailability.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Epididymal Cyst - A Case Study

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    Cysts of the epididymis are usually congenital and derived from an embryonic remnant. These cysts are due to cystic degeneration of remnants of the paramesonephric or Mullerian duct and Remnants of the mesonephric duct or Wolffian duct system. Here we report a case of bilateral Epididymal cysts in a middle aged man with a complaint of scrotal lump and infertility since 15 years. He was treated with excision of the cysts under local anaesthesia and had a marked improvement in scrotal discomfort and urgency of micturition after the treatment

    Sharp change over from compound nuclear fission to shape dependent quasi fission

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    Fission fragment mass distribution has been measured from the decay of 246^{246}Bk nucleus populating via two entrance channels with slight difference in mass asymmetries but belonging on either side of the Businaro Gallone mass asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb barrier, at similar excitation energies the width of the fission fragment mass distribution was found to be drastically different for the 14^{14}N + 232^{232}Th reaction compared to the 11^{11}B + 235^{235}U reaction. The entrance channel mass asymmetry was found to affect the fusion process sharply.Comment: 4 pages,6 figure

    Enzyme Activity Profiles Produced on Wood and Straw by Four Fungi of Different Decay Strategies

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    Four well-studied saprotrophic Basidiomycota Agaricomycetes species with different decay strategies were cultivated on solid lignocellulose substrates to compare their extracellular decomposing carbohydrate-active and lignin-attacking enzyme production profiles. Two Polyporales species, the white rot fungus Phlebia radiata and brown rot fungus Fomitopsis pinicola, as well as one Agaricales species, the intermediate “grey” rot fungus Schizophyllum commune, were cultivated on birch wood pieces for 12 weeks, whereas the second Agaricales species, the litter-decomposing fungus Coprinopsis cinerea was cultivated on barley straw for 6 weeks under laboratory conditions. During 3 months of growth on birch wood, only the white rot fungus P. radiata produced high laccase and MnP activities. The brown rot fungus F. pinicola demonstrated notable production of xylanase activity up to 43 nkat/mL on birch wood, together with moderate β-glucosidase and endoglucanase cellulolytic activities. The intermediate rot fungus S. commune was the strongest producer of β-glucosidase with activities up to 54 nkat/mL, and a notable producer of xylanase activity, even up to 620 nkat/mL, on birch wood. Low lignin-attacking but moderate activities against cellulose and hemicellulose were observed with the litter-decomposer C. cinerea on barley straw. Overall, our results imply that plant cell wall decomposition ability of taxonomically and ecologically divergent fungi is in line with their enzymatic decay strategy, which is fundamental in understanding their physiology and potential for biotechnological applications

    Enzyme Activity Profiles Produced on Wood and Straw by Four Fungi of Different Decay Strategies

    Get PDF
    Four well-studied saprotrophic Basidiomycota Agaricomycetes species with different decay strategies were cultivated on solid lignocellulose substrates to compare their extracellular decomposing carbohydrate-active and lignin-attacking enzyme production profiles. Two Polyporales species, the white rot fungus Phlebia radiata and brown rot fungus Fomitopsis pinicola, as well as one Agaricales species, the intermediate “grey” rot fungus Schizophyllum commune, were cultivated on birch wood pieces for 12 weeks, whereas the second Agaricales species, the litter-decomposing fungus Coprinopsis cinerea was cultivated on barley straw for 6 weeks under laboratory conditions. During 3 months of growth on birch wood, only the white rot fungus P. radiata produced high laccase and MnP activities. The brown rot fungus F. pinicola demonstrated notable production of xylanase activity up to 43 nkat/mL on birch wood, together with moderate β-glucosidase and endoglucanase cellulolytic activities. The intermediate rot fungus S. commune was the strongest producer of β-glucosidase with activities up to 54 nkat/mL, and a notable producer of xylanase activity, even up to 620 nkat/mL, on birch wood. Low lignin-attacking but moderate activities against cellulose and hemicellulose were observed with the litter-decomposer C. cinerea on barley straw. Overall, our results imply that plant cell wall decomposition ability of taxonomically and ecologically divergent fungi is in line with their enzymatic decay strategy, which is fundamental in understanding their physiology and potential for biotechnological applications

    Designing of a comprehensive format for the analysis of Deha Prakruti

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    Prevalence of life style disorders has reached alarming proportions among Indians in the recent years. So prevention of life style disorders is a challenge now a days. Ayurveda provides a definite ray of hope for this. Prakruti in Ayurveda is the expression of person in context of morphology, Physiology, behavior and relation to ecology. To provide such guidelines on individual basis consideration of Deha Prakruti is important parameter. So it is a need of Ayurveda practitioner to have a precise format for diagnosis of exact Deha Prakruti in short period for convenience of OPD patients. Present study is effort to design a concise format for Deha Prakruti analysis

    Pemetaan Daerah Rawan Erosi dengan Menggunakan Aplikasi Penginderaan Jauh dan Sistem Informasi Geografi di Kabupaten Timor Tengah Selatan Propinsi Nusa Tenggara Timur

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    Telah dilakukan pemetaan daerah rawan erosi di Kabupaten Timor Tengah Selatan Provinsi Nusa Tenggara Timur dengan menggunakan aplikasi penginderaan jauh dan sistem infomasi geografi. Tujuan dari penelitian ini adalah  untuk memetakan daerah rawan erosi dan tingkat kerawanannya di Kabupaten Timor Tengah selatan, Propinsi Nusa Tenggara Timur. Metode penelitian berupa pembuatan peta curah hujan, pembuatan peta tutupan lahan, dan pembuatan peta kelas lereng. Berdasarkan dari hasil penelitian, tingkat rawan erosi dibagi menjadi tiga kelas yaitu: kelas tidak rawan erosi  dengan luas wilayah 127.218,69 Ha meliputi kecamatan Noebeba, kecamatan Amanuban Selatan, kecamatan Kualin, sebagian kecamatan Amanuban Timur dan kecamatan Fatukopa. Kelas  rawan erosi  dengan luas wilayah 251.082,09 Ha meliputi hampir seluruh kecamatan Timor Tengah Selatan dan kelas sangat rawan erosi sekitar 9.125,1 Ha meliputi wilayah kecamatan Fatumnasi, kecamatan Tobu, kecamatan Mollo Utara, sebagian kecamatan Kot'olin. Kata kunci: Peta Rawan Erosi, Penginderaan Jauh, Sistem Informasi Geografi. &nbsp
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