Massive multiple-input-multiple-output (MIMO) is considered as one of the major technologies for 5G communications, implementing huge elements of antenna array to boost spectral efficiency, robustness, and reliability. However, massive... more
Massive multiple-input-multiple-output (MIMO) is considered as one of the major technologies for 5G communications, implementing huge elements of antenna array to boost spectral efficiency, robustness, and reliability. However, massive deployment of MIMO antenna elements also increases power consumption, which ultimately cannot fulfill another important design criterion of 5G communications, i.e., energy- efficiency. In addition, huge deployment of closely spaced antenna also increases co-channel interference. Nakagami-m fading channel has the m diversity order to minimize interference in different fading distributions. Based on base station antennas distribution, massive MIMO can be classified as co-located, distributed, and hybrid. In this paper, we investigate the energy efficiency of massive MIMO systems for different distributions using MMSE (minimum mean square error) detector in Nakagami-m fading channel. Simulation results show that the high energy efficiency can be exploited in hybrid system compared to other two MIMO distributions. Moreover, the trade-off between spectral efficiency and energy efficiency with signal-to-noise ratio (SNR) is also portrayed for different distribution.
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Biological markers for assessment of exposure to a variety of environmental carcinogens has been widely applied in both basic as well as clinical research. Exposure to tobacco smoke presents an ideal environment with which to develop,... more
Biological markers for assessment of exposure to a variety of environmental carcinogens has been widely applied in both basic as well as clinical research. Exposure to tobacco smoke presents an ideal environment with which to develop, characterize, and refine biological markers, especially of those carcinogens found in tobacco. In the present study, a sensitive gas chromatography/mass spectrometry (GC/MS) method was developed to measure nitrosamine- hemoglobin adducts (HPB-Hb (4-Hydroxy-3-pyridinyl-1-butanone) at trace levels in red blood cells of both African-American and Caucasian smoking and nonsmoking mothers and their infants. Gas chromatographic and mass spectrometric methods with chemical ionization (CI) of methane reagent gas in both positive and negative ion mode as well as electron ionization (EI) were studied to determine differences in sensitivity of detection among the various ionization methods. Detection limits using both positive and negative chemical ionization mode...
Research Interests: Bioinformatics, Evolutionary Biology, Pathology, Oncology, Informatics, and 15 moreGenomics, Computational Biology, Biotechnology, Cancer, Biomarkers, Biology, Biomedical informatics, Medicine, Bioscience, Microarray, Clinical Medicine, Biological, Genetic modification, Evidence Based, and Original research
ABSTRACT Electrical discharge machining (EDM) is one of the non-traditional machining processes normally used in manufacturing very hard materials that are electrically conductive. Tool electrodes form one of the main components of the... more
ABSTRACT Electrical discharge machining (EDM) is one of the non-traditional machining processes normally used in manufacturing very hard materials that are electrically conductive. Tool electrodes form one of the main components of the machining system. The major properties that determine the suitability of such electrodes are electrical conductivity, thermal conductivity and density. The objective of this paper is to present the use of Artificial Neural Network (ANN) architecture in modeling these properties. In the research, Cu-TaC electrode compacts were produced at two levels each of the composition and the compacting pressures from copper and tantalum carbide powders for use in EDM. The compositions of the Cu-TaC are made of 30 % and 55 % wt of TaC, while the compacting pressures are 1, 500 psi and 3,000 psi. They were subjected to sintering at temperatures of 450°C and 850 °C. The properties were measured before and after sintering. Results showed that the sintered electrodes are not suitable for EDM because they lost their electrical conductivity. The pre-sintered electrodes (green compacts) were however found to suitable for EDM. Artificial neural network technique with 16 experimental runs was used to develop the new models for predicting the electrical conductivity, thermal conductivity and density of the green compacted electrodes. The models were been built by using MATLAB 2009b. Results show that ANN models are capable of predicting the electrode properties with high degree of prediction accuracy compared to the experimental results.
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Orthogonal frequency division multiplexing (OFDM) is a promising modulation radio access scheme for next generation wireless communication systems because of its inherent immunity to multipath interference due to a low symbol rate, the... more
Orthogonal frequency division multiplexing (OFDM) is a promising modulation radio access scheme for next generation wireless communication systems because of its inherent immunity to multipath interference due to a low symbol rate, the use of a cyclic prefix, and its affinity to different transmission bandwidth arrangements. OFDM has already been adopted as a radio access scheme for several of the latest cellular system specifications such as the long-term evolution (LTE) system in the 3GPP (3rd Generation Partnership Project). Nevertheless, peak-to-average power ratio (PAPR) of OFDM signal is a significant drawback since it restricts the efficiency of the transmitter. A number of promising approaches have been proposed & implemented to reduce PAPR with the expense of increase transmit signal power, bit error rate (BER) & computational complexity and data rate loss, etc. In this paper, a relatively better scheme of amplitude clipping & filtering operation (ACF) is proposed and imple...
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Research Interests: Chemistry, Air pollution, Medicine, Signal Transduction, Estrogen Receptor, and 15 moreCell line, Humans, Endothelial Cells, Nitric oxide, Vehicle Emissions, Electrical Resistance, Polycyclic Aromatic Hydrocarbon, Akt, Endothelial cell, Particulate Matter, Intracellular Signaling, Estradiol, ENVIRONMENTAL SCIENCE AND MANAGEMENT, cardiovascular mortality, and Pharmacology and pharmaceutical sciences
In the area of grit blasting, it is well known that microscopically small abrasive debris gets trapped on the surface, and due to impact the grits might cause the surface to fracture and a fraction of it to be embedded. The same problem... more
In the area of grit blasting, it is well known that microscopically small abrasive debris gets trapped on the surface, and due to impact the grits might cause the surface to fracture and a fraction of it to be embedded. The same problem appears in abrasive water jet (AWJ) machining especially in the so-called deformation wear zone or striation zone. The major aim in this study is to investigate the abrasive contamination on mild steel cutting surface. In the present study mild steel was used as the work material, since it is widely used in many industries. In order to analyze the pattern of the contaminations on the cut surface, the selected process parameters were abrasive flow rate, pressure and work feed rate. Abrasive contamination was measured at different depths along the path of the abrasives. The three selected zones for measuring abrasive contamination at different depths were the primary impact zone, the smoother zone and the deformation wear zone. It was found that contam...
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During the last decade, there have been signs of increased democratization in the Middle East. Yet women's political rights remain limited. In this article we focus on Kuwait, a country representative of how citizenship rights have... more
During the last decade, there have been signs of increased democratization in the Middle East. Yet women's political rights remain limited. In this article we focus on Kuwait, a country representative of how citizenship rights have been gendered in the Middle East. Some Kuwaiti women's groups support expanding women's political rights. This article seeks to determine if they have potential allies in the general population. Using survey data from 1500 Kuwaiti citizens in 1994, we identify potential advocates for extending women's rights by examining social status, social networks, religious identity and Gulf War experiences. We found that organized women's groups have potential allies in Sunni young people and men who belong to voluntary organizations, and Shia young men, older women and those who backed Islamic movements abroad. These groups form a basis for developing a broad base of popular support for expanding the citizenship rights of women.
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... Address correspondence to Steven Myers, Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 500 South Preston St., Louisville, KY 40292. E-mail: Sr.myers@louisville.edu 143 ... REFERENCES 1. WM... more
... Address correspondence to Steven Myers, Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 500 South Preston St., Louisville, KY 40292. E-mail: Sr.myers@louisville.edu 143 ... REFERENCES 1. WM Baird, LA Hooven, and B. Mahadevan. ...
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This paper discusses the investigation of geometrical integrity of micromold cavity produced by focused ion beam (FIB) sputtering slice by slice. Parabolic shaped micromold cavity was chosen as an example. Preliminary experiments were... more
This paper discusses the investigation of geometrical integrity of micromold cavity produced by focused ion beam (FIB) sputtering slice by slice. Parabolic shaped micromold cavity was chosen as an example. Preliminary experiments were carried out to characterize the machine and select the optimum process parameters such as beam current, pixel spacing, aperture size, and dwell time. The geometrical integrity of
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In biological matrixes lipid material often poses an interference problem for determinations of nonpolar compounds, e.g., polycyclic aromatic hydrocarbons (PAHs). A newly developed supercritical fluid extraction plus adsorbent method,... more
In biological matrixes lipid material often poses an interference problem for determinations of nonpolar compounds, e.g., polycyclic aromatic hydrocarbons (PAHs). A newly developed supercritical fluid extraction plus adsorbent method, "SFE-plus-C(18)", offers selective extraction of PAHs in lipid-rich biological matrixes without the need for supplementary cleanup. This method eliminates the use of large volumes of toxic solvent and lengthy lipid removal procedures. This study reports the first application of the SFE-plus-C(18) method to the analysis of a genuine food product, i.e., smoked meat (beef). The procedure employs the addition of C(18) adsorbent beads to the initial sample slurry of pureed smoked meat prior to supercritical CO(2) extraction and GC/MS quantitation. During SF extraction, indigenous lipids are preferentially retained on the beads, and PAHs are selectively extracted with supercritical CO(2). In a comparison of determinations of PAHs by SFE-plus-C(18) vs the conventional SFE method, only 11-17% of the indigenous lipids observed by the conventional SFE method were co-extracted using the SFE-plus-C(18) method. The PAHs in smoked meat could thus be determined efficiently in the presence of a reduced background of co-extracted lipids. Out of 10 targeted PAHs, seven were detected with a range of 10.0-26.0 ng/g in the smoked meat sample. The other three PAHs were not present above the detection limit of the instrument (2.5-4.1 pg). The recoveries of PAHs obtained using the conventional SFE method were 63-94% lower than those achieved by SFE-plus-C(18).
Research Interests: Engineering, Chemistry, Carbon Dioxide, Chromatography, Mass Spectrometry, and 15 moreMedicine, Lipids, Toxicity, Animals, Meat, Gas Chromatography, CHEMICAL SCIENCES, Cattle, Polycyclic aromatic hydrocarbons (PAHs), Interference, Supercritical Fluid Extraction, Gas Chromatography/mass Spectrometry, Agricultural and Food Chemistry, Carcinogen, and measurement accuracy
Research Interests: Mechanical Engineering, Materials Science, Surface Roughness, Focused Ion Beam, Manufacturing Engineering, and 14 moreSputtering, Ion, Scanning Electron Microscope, Microstructures, Three Dimensional, Atomic Force Microscope, Ion Beam, Material Removal Rate, Dwell Time, Aspect Ratio, Precision Engineering, Empirical Model, Surface Texture, and High aspect ratio
Research Interests: Chemistry, Kinetics, Mass Spectrometry, Medicine, Mice, and 14 moreAnimals, Glutathione, Chemico-biological Interactions, GAS LIQUID CHROMATOGRAPHY, Glutathione Transferase, Elsevier, Erythrocytes, Oxidation-Reduction, Hemoglobins, Biochemistry and cell biology, Nucleic Acid, Volatilization, Valine, and stereoisomerism
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Micro-electro discharge machining (micro-EDM) technique, an advanced noncontact machining process, is used for structuring of nonconductive ZrO2 ceramic. In this study copper foil as a conductive layer is adhered on the workpiece surface... more
Micro-electro discharge machining (micro-EDM) technique, an advanced noncontact machining process, is used for structuring of nonconductive ZrO2 ceramic. In this study copper foil as a conductive layer is adhered on the workpiece surface to initiate the sparks and kerosene is used as dielectric for creation of continuous conductive pyrolytic carbon layer on the machined surface. Voltage (V) and capacitance (C) are considered as the parameters to investigate the process capability of machining parameters in continuous micro-EDM of ZrO2. Different voltage pulses are studied to examine the causes of lower material removal rate (MRR) in micro-EDM of nonconductive ceramics. The results showed that in micro-EDM of ZrO2 MRR increases with the increase of voltage and capacitance initially, but decreases at higher values and no significant materials are removed at capacitances higher than 1nF.
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English as a language is an essential tool in the negotiation of power and relationship at the interpersonal, social and the global level as well. The importance of learning English has increased significantly as a useful communication... more
English as a language is an essential tool in the negotiation of power and relationship at the interpersonal, social and the global level as well. The importance of learning English has increased significantly as a useful communication tool in the age of globalization. In the existing scenario, English language learning and teaching in the rural areas of Bangladesh has become a prime concern. This study aims to present the current English language education policy, language learning and teaching obstacles pertaining to the poorly equipped classroom, lack of trained language teachers, and inadequate use of technology and non-availability of learning materials in Bangladesh. To analyze and to find the solution to the language teaching and learning obstacles, the researcher employed both qualitative and quantitative methods. The research was carried out in ten rural colleges far from the capital city Dhaka. The population of this study was higher secondary level students in the academi...
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Lipid material represents a potential interference for determination of nonpolar compounds (e.g., polycyclic aromatic hydrocarbons) in biological tissue samples. This study reports the development of a selective extraction method using... more
Lipid material represents a potential interference for determination of nonpolar compounds (e.g., polycyclic aromatic hydrocarbons) in biological tissue samples. This study reports the development of a selective extraction method using supercritical CO2 that allows the GC/MS quantitation of PAHs in the presence of a substantial lipid background. Selective extraction of PAHs relies upon addition of C18 adsorbent beads to the initial sample slurry. The dried mixture, including C18 adsorbent, is placed in the supercritical fluid extraction (SFE) chamber. During the SFE process, lipids are preferentially retained on the C18 beads. This "SFE plus C18" procedure was developed by first optimizing SFE conditions (100 degrees C, 350 bar) for recovery of PAH standards. PAHs containing added model lipid compounds (stearic acid and cholesterol) were then subjected to SFE plus C18 treatment followed by GC/MS analysis. Using this approach, a recovery of 94-100% of PAHs was obtained while only 9-17% of the lipid material present was coextracted from the same test sample. The developed method is demonstrated to permit efficient recovery and detection of PAHs spiked into crab tissue, a matrix with a high lipid content.