398 research outputs found
Comprehensive design and propagation study of a compact dual band antenna for healthcare applications
In this paper, a dual band planar inverted F antenna (PIFA) has been investigated for cooperative on- and off-body communications. Free space and on-body performance parameters like return loss, bandwidth, radiation pattern and efficiency of this antenna are shown and investigated. The on- and off-body radio propagation channel performance at 2.45 GHz and 1.9 GHz have been investigated, respectively. Experimental investigations are performed both in the anechoic chamber and in an indoor environment. The path loss exponent has been extracted for both on- and off-body radio propagation scenarios. For on-body propagation, the path loss exponent is 2.48 and 2.22 in the anechoic chamber and indoor environment, respectively. The path loss exponent is 1.27 for off-body radio propagation situation. For on-body case, the path loss has been characterized for ten different locations on the body at 2.45 GHz, whereas for off-body case radio channel studies are performed for five different locations at 1.9 GHz. The proposed antenna shows a good on- and off-body radio channel performance
Investigating the Role of Operating Parameters and Surface Treatments of Carbon Based Electrodes in Capacitive Deionization
This research focused on studying salt ion removal behavior and regeneration of electrodes used in capacitive deionization (CDI). CDI is a novel deionization technology that utilizes electrochemical processes to extract ions from water and either hold them electrostatically on the electrode surface or trap them in a double layer formed next to surface of electrodes. The use of porous carbon materials as electrodes in CDI enhances ion removal capacity because of availability of high surface area, conductivity, porosity, non-corrosive behavior, and other favorable properties. Experiments were conducted with a synthetic NaCl solution prepared in the laboratory. The first part of this dissertation focused on studying the adsorption and desorption behavior of CDI electrodes under various operating parameters. The effects of applied voltage, ambient temperature, flow rate, and initial concentration of solution on the salt removal behavior of CDI electrodes during the adsorption stage were studied. An isotherm study was conducted to model the data obtained during adsorption stage. Regeneration of saturated/exhausted CDI electrodes was achieved through desorption with observed variables being applied reverse potential, duration of applied reverse potential, ambient temperature, and flow rate. The second part of this research focused on studying salt removal behavior of CDI electrodes before and after surface treatment. Two types of surface treatments were studied – nitric acid treatment and gold deposition on electrode surface. This is the first study to use novel gold deposited carbon/aerogel fiber paper-based electrodes in CDI experiments. The salt removal behavior of treated electrodes was studied for two symmetric (same electrode on both sides as positive and negative) and two asymmetric (treated electrode on one side and untreated on the other side) electrode configurations. The results from these configurations were compared with symmetric configuration of untreated electrodes (both positive and negative electrodes are untreated). The characteristics of the electrodes before and after surface treatment were assessed based on scanning electron microscopy (SEM), three-dimensional laser confocal microscopy, cyclic voltammetry (CV), Fourier transform spectroscopy (FTIR), and surface area and porosity measurement from BET isotherm analysis. The highest salt removal capacity achieved was 8.0 mg/g of NaCl when a gold-deposited electrode was used as an anode and an untreated electrode was used as a cathode
Experimental study of on-body radio channel performance of a compact ultra wideband antenna
In this paper, on-body radio channel performance of a compact ultra wideband (UWB) antenna is investigated for body-centric wireless communications. Measurement campaigns were first done in the chamber and then repeated in an indoor environment for comparison. The path loss parameter for eight different on-body radio channels has been characterized and analyzed. In addition, the path loss was modeled as a function of distance for 34 different receiver locations for propagation along the front part of the body. Results and analysis show that, compared with anechoic chamber, a reduction of 16.34% path loss exponent is noticed in indoor environment. The antenna shows very good on-body radio channel performance and will be a suitable candidate for future efficient and reliable body-centric wireless communications
Efficacy of Geosynthetic Separators and Filters: An Evaluation of Test Sections in Marked Tree, Arkansas
Field and laboratory tests were conducted on 18 full-scale, geosynthetic reinforced, roadway test sections located in Marked Tree, Arkansas. Base course, geosynthetic, and subgrade samples were collected, and pavement depth, in-situ density and in-situ hydraulic conductivity measurements were obtained during a geotechnical site investigation. The performance of sections containing geotextile products being used for separation and filtration (Carthage Mills FX-66, Mirafi 570, Propex 2006, Propex 2044, and Propex 4553) was investigated.
Moisture content, sieve analysis, Atterberg limits, modified proctor, specific gravity, and hydraulic conductivity tests were performed on the acquired soil samples. Transmissivity and permittivity testing was conducted on the geotextile samples. Performance of the flexible pavement system was monitored (annual inspections performed) by Arkansas State Highway and Transportation Department (AHTD) personnel.
The hydraulic conductivity values determined in field were validated using the empirically obtained Moulton (1980) equation and the effective particle size, porosity, and fines content obtained from the forensic analysis. The base course was identified to be non-freely draining (hydraulic conductivity
Excessive rutting was observed in six-inch thick sections containing the Carthage Mills FX-66 geotextile product. Also, more rutting, alligator cracking, and ponding was observed in the six-inch thick sections than the ten-inch thick sections, regardless of the presence of geosynthetics. Based on the results of this research, the wrong types of geotextile fabrics were originally installed at the Marked Tree Test Section. The geotextile fabrics, as installed at the base course/subgrade interface, did not improve the performance of the pavement system. It is recommended that geotextile design criteria be met prior to installation, and that the current geotextiles be day-lighted to provide enhanced drainage
Evaluación de la intensidad de la temperatura de la superficie terrestre en el distrito de Thiruvarur
Nature gives way to the emergence of concrete jungles as cities grow around them. The majority of these concrete masses are highly reflective, changing the surrounding temperature. Hence, urbanized regions often have higher average temperatures than their surrounding rural areas. This phenomenon is termed Urban Heat Island (UHI). The intensity of UHI depends up on Land Surface Temperature (LST). This paper intends to study the intensity of LST in the Thiruvarur district and its correlation with Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) using Landsat 8 Imageries (OLI & TIRS) of January 2018. To calculate the LST, we used the mono-window algorithm. The result shows that LST intensity varies from 20.68°C to 32.3°C, with the maximum being in built-up areas and the minimum being in vegetation areas and water bodies. The Pearson regression shows that there is a negative correlation (r = -0.925, P < 0.5) between LST & NDVI and a positive correlation (r = 0.925, P < 0.5) between LST and NDBI. The strong positive correlation of NDBI confirms the influence of urbanization on Surface Urban Heat Island (SUHI). The negative correlation between LST and NDVI shows that green covers can mitigate it. Hence, this study conclusively demonstrates that urbanization can raise temperatures, showing that sustainable development in cities is essential for sustainable growth
A Study on the Rearing Performance of the Muga Silkworm, Antheraea assamensis, Helfer on the Basis of The Different Host Plant.
The Muga Silkworm, Antheraea assamensis is a polyphagous insect having many host plants. The quality and quantity of the pupation and silk content are greatly determined by the avaibility of the plants, the nutritional level of the leaves along with the growing conditions of the particular area. The study was conducted by feeding the Silkworm with its two primary host plants, Persea bombycina (Som) and Litsea monopetala (Soalu) to draw a quantitative estimate on the rearing performance of the two host plants. It was seen that the male and female larval weight was more in case of Soalu plant which can be attributed to the greater moisture content of the plant. The male and female shell weight was greater in case Som plant. In case of cocoon weight, Som fed males had heavier cocoons whereas Soalu fed females had heavier cocoon. The ERR was more for the silkworms fed with Som plant
Application of Lignin (Modified/Unmodified ) to Cement and Observing Effects
Biomass of various types have been known to be important sources of energy or raw material for products in industries for centuries. Biomass have been proven to be cost effective as sources of suitable chemicals that can enhance many industrial processes. Lignin is one of many very valuable components extractable from biomass. Using lignin, modified or unmodified, can improve the sustainability of manufacturing processes. In this work, lignin was extracted from two different biomass, i.e. coffee chaff and sugarcane bagasse. Coffee chaff is the dried skins of coffee beans, the waste product from the roasting process. Sugarcane bagasse is the fibrous material remaining once the juice is extracted from the sugarcane. It can be dried and combusted as a solid biofuel. A deep eutectic solvent (DES) was used to extract lignin from these two biomass. DESs are hydrogen-bonded solvents that can extract lignin from biomass. They are safe, simple, cost effective and recyclable. In this study, the DES used was a two to one molar ratio of formic acid with choline chloride (FA:CC). The lignin extracted from the two biomass was added to cement to discover how they impacted the plasticity, porosity and compression strength of cement cylinders. In addition, commercially purchased sugarcane bagasse lignin was carboxymethylated and added to cement to investigate its effect on these properties
Performance of Carbon Aerogel/Fiber Paper as Capacitive Deionization Electrodes under Variable Operating Conditions
The capacitive deionization has garnered renewed interested with recent modifications resulting in efficient (energy and cost) alternatives to desalinate brackish water (salt concentration less than 10 g/L). Recent research efforts, to improve the technology, have been focused mainly on electrode material development and modifications of operational parameters for optimized performance. This research is focused on performance evaluation of carbon aerogel/fiber paper as capacitive deionization electrodes under variable operating conditions. The main operational parameters that were varied are applied voltage, influent temperature and initial concentration. The highest adsorption capacity achieved in this on-going study is 4.61 mg/g at 33.5 oC with NaCl solution of 300 mg/L initial concentration, at a rate of 12 mL/min flow rate and 1 V of applied DC voltage. The results obtained by varying operating conditions in this study will provide greater understanding on suitability of these electrodes in capacitive deionization based full-scale capacitive desalination plants
Prediction of outcome of tubal ectopic pregnancy on the basis of site of implantation of embryo in the fallopian tube
Background: Ectopic pregnancy is a high-risk condition that occurs in 1.9 percent of reported pregnancies. The condition is the leading cause of pregnancy-related death in the first trimester. If a woman of reproductive age presents with abdominal pain, vaginal bleeding, syncope, or hypotension, the physician should perform a pregnancy test. If the patient is pregnant, the physician should perform a work-up to detect possible ectopic or ruptured ectopic pregnancy.Methods: This study was an observational analytical type of study in which all the diagnosed cases of tubal ectopic were included. Detailed history and clinical evaluation was done and information was collected in a pre-tested proforma. Data was analyzed by frequency, percentages and chi square test.Results: In this study total 50 cases were studied. In this we found a significant correlation between site of implantation in tubal ectopic and its final outcome.Conclusions: Early detection of tubal ectopic and its site of implantation can help in deciding further management especially to go for conservative or surgical management.
Autonomous Administration of Corporation through Workers Participation in Management
Workers participation in management, also known as WPM, is an advanced type of labour management cooperation that guarantees the concept of autonomous and democratic administration of a company in order to achieve peace and harmony in the workplace. As a consequence, a greater understanding and mutual trust may be established between the company and the employees. A constant communication between them helps to maintain industrial harmony and increase worker loyalty. This plan contributes to increased output and productivity, as well as the equitable distribution of productivity gains, via more effective management and improved industrial relations. However, all of the efforts undertaken by the government, employers, and other employees to increase the involvement of workers in industrial management have fallen short of the goals for which they were intended in India. This research examines Women's Participation in Medicine (WPM) in India and makes an effort to determine the reasons for low participation rates. It also makes some useful recommendations for overcoming the issu
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