145 research outputs found
Characterization of embroidered dipole-type RFID tag antennas
Radio Frequency Identification (RFID) is a technology which is used for automatic identification of objects. A typical RFID system consists of a stationary radio-scanner unit, called reader, and a movable transponder, called tag, which is attached to an object. The tags include an antenna and a microchip with internal read/write memory.
Tag antenna plays an important role in the overall RFID system performance factors, such as the read range, and the compatibility with tagged objects. This thesis focuses on garment-integrated embroidered tags which can be used for the means of human monitoring and identification. The embroidered tag antennas are sewed on fabric using conductive threads and computer aided sewing machine.
Modeling of embroidered tag antennas is not a straightforward task, because embroidered antennas do not have a distinct conductivity, which could be used in the simulation model of them. In fact, conductivity of sewed flat conductive layer depends on the selection of the conductive thread, the thread and stitch density and the sewing pattern. The aim of this thesis has been to investigate the effect of these factors on the conductivity, and evaluate conductivity values for the embroidered dipole-type RFID tag antennas.
In this project, T-matched dipoles have been sewed on cotton with two different sewing patterns and also with many different stitch densities. The effect of the geometry of the antenna is also investigated by sewing and measuring straight simple dipoles with both sewing patterns. The achieved read range values of the sewed tag antennas have been up to 7.5 m.
In this thesis it is proved that each sewing pattern has its own conductivity and con-ductivity of a sewing pattern improves if the pattern consists of sewed lines along the direction of current flow. It is not necessary to sew the antenna with a high thread and stitch density. We can achieve high conductivities even from very sparsely sewed an-tennas, using less conductive threads and spending considerably less time on sewing.
The evaluated conductivities and the presented simulation model of the sewed dipoles in this project can be used in future for optimization of the sewed antennas to operate in the vicinity of body
Socioeconomic Inequalities in Tobacco Smoking in Women Aged 15-54 in Iran: A multilevel model
Significant evidence suggests an inverse relationship between socioeconomic status and tobacco smoking, where inequality is visible among different social and economic strata. The aim of this study was to investigate the prevalence and economic and social inequalities in tobacco smoking in women aged 15-54 in Iran. This study is a cross-sectional study. Sampling in this study was a randomized clustered multistage sampling with equal clusters. A total of 35,305 women aged 15-55 enrolled in the study. Data analysis was in two stages. In the first stage, the social and economic inequalities were investigated using the concentration index and concentration curve method, and in the second method, and multilevel method was used to identify the determinants. The prevalence of tobacco smoking in women was 12.24%. The concentration index for smoking was CI = -0.07 [95% CI (-0.09, -0.05)], which represents smoking in people with low socioeconomic status. The results of the multilevel analysis indicated that the marital status of people over the age of 35 and the economic class was related to smoking in women. Inequality in tobacco smoking in women is to the interest of the well-off group, and this inequality varies in different provinces. Marital status, place of residence, age and socioeconomic status of women are factors influencing the prevalence of tobacco smoking in women, and these issues should be noticed to reduce inequalities
Maternal risk factors for low birth weight infants: A nested case-control study of rural areas in Kurdistan (western of Iran)
Infant mortality is among the most important indicators of health and development in global communities. One of the causes of neonatal mortality is low birth weight. This study aims at evaluating the risk factors for LBW in infants.This study was carried out using a nested case-control study in rural areas of Kurdistan province in western Iran in 2015. The selection of case and control groups was based on the nesting using the risk set sampling approach. In total, 182 and 364 subjects were selected for the case group and the control group respectively. Data analysis was performed using the Stata-12 software with the point and spatial estimation of OR using the conditional logistic regression method.The multivariate logistic regression analysis performed shows that the maternal gestational age, the mother’s health history during pregnancy, any medication abuse by the mother, any mental stress during pregnancy, are LBW risk factors (P <0.05). Prevention of LBW is possible by identifying effective factors and performing appropriate interventions in infants with low birth weight. The causes of LBW in global communities are changing rapidly. Mothers with the risk factors reported in this study should be identified and specially treated
Effect of Er: YAG Laser on Microtensile Bond Strength of Bleached Dentin to Composite
Introduction: In non-vital tooth bleaching, dentin is in direct contact with the bleaching agent, 1 to 3-week delay is needed to eliminate free radicals from tooth structure. The present study aimed to evaluate the effect of irradiation of Er: YAG laser on immediate microtensile bond strength of bleached dentin to composite.Methods: Sixty sounds human teeth were collected and randomly divided into 4 groups (n = 15): no bleaching (NB), opalescence endo hydrogen peroxide (HP) gel bleaching, sodium perborate (SP) bleaching and laser bleaching with heydent gel (LB). The groups were divided into 3 subgroups (n = 5): no surface treatment, Er: YAG laser irradiation and 10% sodium ascorbate (SA). All samples were restored and underwent microtensile bond strength testing. Statistical analysis was carried out using one-way and two-way ANOVA.Results: Bond strength in NB-SA group had a significant difference with the NB group (P < 0.05) while no significant difference was noted between NB and NB-Er groups (P = 0.55). Application of SA and Er: YAG laser after bleaching with SP did not enhance the bond strength (P = 0.07).Conclusion: Application of SA and Er: YAG laser after HP gel bleaching significantly enhanced the bond strength. Application of Er: YAG laser after internal bleaching with HP gel could enhance the bond strength
Diffuse Multifocal Bilateral Dysembryoplastic Neuroepithelial Tumor: A Very Unusual Case Report
Dysembryoplastic neuroepithelial tumor (DNT) considered as a benign cortical Glioneuronal neoplasm of children or young adults, typically present with drug-resistant focal epilepsy. DNTs are usually located in the temporal lobe but can found in any part of the supratentorial brain cortex. Multifocal DNTs have rarely reported. Here we present an eight years old boy with two years follow up, having a somewhat stable diffuse multinodular DNT of the most significant spatial extent that may have reported, involving cortical and subcortical left temporo-occipital lobe, bilateral basal ganglia and thalamus, presenting with headache, short stature, and behavioral disorder
Biotelemetric Wireless Intracranial Pressure Monitoring: An In Vitro
Assessment of intracranial pressure (ICP) is of great importance in management of traumatic brain injuries (TBIs). The existing clinically established ICP measurement methods require catheter insertion in the cranial cavity. This increases the risk of infection and hemorrhage. Thus, noninvasive but accurate techniques are attractive. In this paper, we present two wireless, batteryless, and minimally invasive implantable sensors for continuous ICP monitoring. The implants comprise ultrathin (50 μm) flexible spiral coils connected in parallel to a capacitive microelectromechanical systems (MEMS) pressure sensor. The implantable sensors are inductively coupled to an external on-body reader antenna. The ICP variation can be detected wirelessly through measuring the reader antenna’s input impedance. This paper also proposes novel implant placement to improve the efficiency of the inductive link. In this study, the performance of the proposed telemetry system was evaluated in a hydrostatic pressure measurement setup. The impact of the human tissues on the inductive link was simulated using a 5 mm layer of pig skin. The results from the in vitro measurement proved the capability of our developed sensors to detect ICP variations ranging from 0 to 70 mmHg at 2.5 mmHg intervals
The Incidence and Geographical Distribution of Brucellosis in Iran Using Geographic Information System and Prediction of its Incidence in 2021
Background: Brucellosis is one of the most challenging health issues in many developing countries including Iran. The purpose of this study is to investigate the incidence and geographical distribution of brucellosis using Geographic Information System (GIS) and to predict its incidence in Iran in 2021.
Method: This is a descriptive-analytical cross-sectional study, which contains spatial and climatic information along with the prevalence rate of brucellosis in Iran. Disease information was obtained from the National Center for Infectious Diseases Management during 2011-2015. Then, Arc GIS version 9.3 was used to plot the geographical maps for the incidence and frequency of the disease. Using the Raster calculator tool, the disease prediction map for the future was plotted. For proper spatial distribution of hot and cold spots, Getis-Ord-Gi statistic was employed.
Results: The highest incidence of brucellosis during 2009-2015 was observed in the western provinces of Iran (North Khorasan, South Khorasan and Razavi Khorasan provinces). The incidence of brucellosis in Iran decreased from 2009 to 2011 but it exhibited an increasing trend from 2011 to 2014. The provinces of Kurdistan, Lorestan, Ilam, Zanjan and Kermanshah may be among the hot spots in terms of brucellosis incidence in 2021.
Conclusion: We predicted significant variations in brucellosis risk distribution in Iran in the coming years. In the western and northwestern provinces, which are among the high risk areas for the incidence of this disease in the future, this disease can pose a serious health threat to the residents of these areas
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