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Search Results: 1 - 10 of 461302 matches for " A Bedri "
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Experimental Design of Photo-Fenton Reactions for the Treatment of Car Wash Wastewater Effluents by Response Surface Methodological Analysis
Maha A. Tony,Zeinab Bedri
Advances in Environmental Chemistry , 2014, DOI: 10.1155/2014/958134
Abstract: Establishing a treatment process for practical and economic disposal of car wash wastewater has become an urgent environmental concern. Photo-Fenton’s process as one of the advanced oxidation processes is a potentially useful oxidation process in treating such wastewater. Lab-scale experiments with UV source, coupled with Fenton’s reagent, showed that hydrocarbon oil is degradable through such a process. The feasibility of photo-Fenton’s process to treat wastewater from a car wash is investigated in the present study. A factorial design based on the response surface methodology was applied to optimize the photo-Fenton oxidation process conditions using chemical oxygen demand (COD) reduction as the target parameter to optimize. The reagent (Fe2+ and H2O2 concentration) and pH are used as the controlling factors to be optimized. Maximal COD reduction (91.7%) was achieved when wastewater samples were treated at pH 3.5 in the presence of hydrogen peroxide and iron in amounts of 403.9 and 48.4?mg/L, respectively. 1. Introduction Car washing leads to disposal of large amounts of oily polluted water which results in potentially high levels of nutrients, metals, and hydrocarbons flowing into storm drains. The composition of pollutants found in car wash wastewater varies according to the way of washing, mechanical car washing or artificial high-pressure water washing, and the size and type of vehicle (e.g., small car, truck, commercial van, etc.). In some cases, car wash wastewater may also contain heavy metals [1–3]. Considering the large volume of wastewater generated from the car washing process, wastewater treatment coupled with recycling may possibly be an essential water quality measure. For instance, in the US, commercial car wash facilities either recycle or treat their wash water prior to discharge to the sanitary sewer system, so most storm water impacts from car washing are from residential car wash systems that discharge polluted wash water into the storm drain system [1]. Some countries, for example, Switzerland, Germany, and The Netherlands, no longer allow outdoor car washing away from car washing stations [4]. In Egypt, as well as in many countries worldwide, car wash activities within petrol stations and outdoor car washing are among those activities that pose an environmental threat to the main freshwater source, the river Nile, which is already subjected to untreated wastewater [5]. Consequently, there is a growing need for research particularly on the application of innovative technologies in the treatment of such kind of wastewater. The
Escenarios de la identidad cultural de los jóvenes espa oles: análisis desde la educación social
Fanny T. Aa?os Bedri?ana
Estudios sobre las Culturas Contemporaneas , 2006,
Abstract: La relación de la humanidad con las drogas se ha dado siempre en las diferentes culturas y épocas, aunque con matices diferenciadores en cuanto a sus usos, significados, tipos de sustancias empleadas. El objeto de la investigación nacional efectuada por el Grupo de Investigación HUM 739 de la Universidad de Granada es, entre otros, aproximarse a la cultura juvenil espa ola buscando la relación con las conductas de consumo de drogas. Así, desde la perspectiva de la Educación Social, los datos analizados en el presente artículo indagan en las motivaciones iniciales de contacto con las drogas (alcohol, tabaco y cannabis), los factores que los sujetos indican que son los mayores influyentes de consumo y las diversas situaciones en las que se producen dichos encuentros. La población estudiada alude a sujetos entre los 12 y 26 a os en un marco muestral de 28 entrevistas en profundidad y 1,030 cuestionarios aplicados tanto en zonas urbanas como rurales del territorio espa ol.
A Reconfigurable Spiral Antenna for Adaptive MIMO Systems
Cetiner Bedri A,Qian JY,Li GP,De Flaviis F
EURASIP Journal on Wireless Communications and Networking , 2005,
Abstract: We present a reconfigurable spiral antenna for use in adaptive MIMO systems. The antenna is capable of changing the sense of polarization of the radiated field. It is fabricated by using an RF-MEMS technology compatible with microwave laminate substrates developed within the author's group. The proposed antenna structure is built on a number of rectangular-shaped bent metallic strips interconnected to each other with RF-MEMS actuators. Two senses of polarization, RHCP and LHCP, are achieved by configuring the physical structure of the antenna, that is, by changing the winding sense of the spiral, through judicious activation of MEM actuators. The fabrication process for the monolithic integration of MEM actuators with bent microstrip pixels on RO4003-FR4 microwave laminate substrate is described. The measured and calculated radiation and impedance characteristics of the antenna are given. The operating frequency of the presented antenna design can easily be adjusted to be compatible with popular IEEE networking standards such as 802.11a.
Full-Duplex Systems Using Multi-Reconfigurable Antennas
Elsayed Ahmed,Ahmed M. Eltawil,Zhouyuan Li,Bedri A. Cetiner
Mathematics , 2014,
Abstract: Full-duplex systems are expected to achieve 100% rate improvement over half-duplex systems if the self-interference signal can be significantly mitigated. In this paper, we propose the first full-duplex system utilizing Multi-Reconfigurable Antenna (MRA) with ?90% rate improvement compared to half-duplex systems. MRA is a dynamically reconfigurable antenna structure, that is capable of changing its properties according to certain input configurations. A comprehensive experimental analysis is conducted to characterize the system performance in typical indoor environments. The experiments are performed using a fabricated MRA that has 4096 configurable radiation patterns. The achieved MRA-based passive self-interference suppression is investigated, with detailed analysis for the MRA training overhead. In addition, a heuristic-based approach is proposed to reduce the MRA training overhead. The results show that at 1% training overhead, a total of 95dB self-interference cancellation is achieved in typical indoor environments. The 95dB self-interference cancellation is experimentally shown to be sufficient for 90% full-duplex rate improvement compared to half-duplex systems.
A Reconfigurable Spiral Antenna for Adaptive MIMO Systems
Cetiner Bedri A.,Qian J. Y.,Li G. P.,De Flaviis F.
EURASIP Journal on Wireless Communications and Networking , 2005,
Abstract: We present a reconfigurable spiral antenna for use in adaptive MIMO systems. The antenna is capable of changing the sense of polarization of the radiated field. It is fabricated by using an RF-MEMS technology compatible with microwave laminate substrates developed within the author's group. The proposed antenna structure is built on a number of rectangular-shaped bent metallic strips interconnected to each other with RF-MEMS actuators. Two senses of polarization, RHCP and LHCP, are achieved by configuring the physical structure of the antenna, that is , by changing the winding sense of the spiral, through judicious activation of MEM actuators. The fabrication process for the monolithic integration of MEM actuators with bent microstrip pixels on RO4003-FR4 microwave laminate substrate is described. The measured and calculated radiation and impedance characteristics of the antenna are given. The operating frequency of the presented antenna design can easily be adjusted to be compatible with popular IEEE networking standards such as 802.11a.
Cultural adaptation of birthing services in rural Ayacucho, Peru
Gabrysch,Sabine; Lema,Claudia; Bedri?ana,Eduardo; Bautista,Marco A; Malca,Rosa; Campbell,Oona MR; Miranda,J Jaime;
Bulletin of the World Health Organization , 2009, DOI: 10.1590/S0042-96862009000900018
Abstract: problem: maternal mortality is particularly high among poor, indigenous women in rural peru, and the use of facility care is low, partly due to cultural insensitivities of the health care system. approach: a culturally appropriate delivery care model was developed in poor and isolated rural communities, and implemented between 1999 and 2001 in cooperation with the quechua indigenous communities and health professionals. data on birth location and attendance in one health centre have been collected up to 2007. local setting: the international nongovernmental organization, health unlimited, and its peruvian partner organization, salud sín límites perú, conducted the project in santillana district in ayacucho. relevant changes: the model involves features such as a rope and bench for vertical delivery position, inclusion of family and traditional birth attendants in the delivery process and use of the quechua language. the proportion of births delivered in the health facility increased from 6% in 1999 to 83% in 2007 with high satisfaction levels. lessons learned: implementing a model of skilled delivery attendance that integrates modern medical and traditional andean elements is feasible and sustainable. indigenous women with little formal education do use delivery services if their needs are met. this contradicts common victim-blaming attitudes that ascribe high levels of home births to "cultural preferences" or "ignorance".
The Need for Management Capacity to Achieve VISION 2020 in Sub-Saharan Africa
Susan Lewallen ,Amir Bedri Kello
PLOS Medicine , 2009, DOI: 10.1371/journal.pmed.1000184
Abstract:
Trichiasis surgery: a patient-based approach
Wondu Alemayehu,Amir Bedri Kello
Community Eye Health Journal , 2010,
Abstract: Trachoma is the leading infectious cause of blindness worldwide. Corneal scarring, which causes trachoma related blindness, occurs when the upper eyelashes are turned inward and rub on the eye (cornea). This is called trichiasis, and if the lid margin turns inward, the term entropion is used. Currently, there are an estimated 8.2 million people with trichiasis and 3.1 million people are blind from trachoma.
National Survey on Blindness, Low Vision and Trachoma in Ethiopia: Methods and Study Clusters Profile
Y Berhane, A Worku, A Bejiga, L Adamu, W Alemayehu, A Bedri, Z Haile, A Ayalew, W Adamu, T Gebre, T D Kebede, E West, S West
Ethiopian Journal of Health Development , 2007,
Abstract: Background: The magnitude and causes of eye diseases in Ethiopia has been derived from small scale studies. This information became no longer useful in tracking the success of intensified efforts in preventing and controlling avoidable causes of blindness and eye diseases in line with the goals of Vision 2020: The Right to Sight. Objective: The national household survey was conducted primarily to provide national and regional state level estimates of low vision, blindness and trachoma. The secondary aims include describing the major causes of low vision and blindness. Methods: The national survey utilized cross sectional epidemiological study design with multistage sampling strategy. All nine regional states and two city administrations of the country were involved in the survey. Sample size and sampling strategies were developed taking into account population size of the regional states. Visual acuity was tested using the LogMar chart and trachoma grading was done following the WHO grading system. The cause of low vision and blindness were determined by ophthalmologists. Results: A total of 174 clusters, 6056 households and 30022 individuals were involved in the survey. Of the total 30022 individuals 25650 (85.4%) were present and examined by the survey team. Implementing quality control supervision in the very remote clusters was a major challenge. About 55% of the survey clusters were within 10 Km of health facility that stock tetracycline; 18.3% within 10 Km of health facility that provides Trachomatous Trichiasis (TT) surgery and 18.6% were within 10Km of health facility that provides cataract surgery. Only 29.4% of the survey clusters were fully accessible by car. The majority of survey household head were farmers (70.8%) and illiterate (64.5%). About 48% of the households obtain their water from either a protected well/spring or piped distribution. Only 40.4% of the households reported that no animal is kept around the living quarter. Most households dispose garbage in open field (84.6%) and have no latrine (60.3%). Conclusion: The survey was conducted on a representative sample and provides reliable estimates at the national and regional levels. However, careful interpretations of results from remote and inaccessible areas are warranted. Access to eye care facilities are limited and need expansion in order to reduce the blindness and low vision load. Sanitation conditions favoring fly breeding are rampant and trachoma control program need to emphasize a more integrated approach. Ethiopian Journal of Health Development Vol. 21 (3) 2007: pp. 185-203
Prevalence and causes of blindness and Low Vision in Ethiopia
Y Berhane, A Worku, A Bejiga, L Adamu, W Alemayehu, A Bedri, Z Haile, A Ayalew, Y Adamu, T Gebre, T D Kebede, E West, S West
Ethiopian Journal of Health Development , 2007,
Abstract: Background: Ethiopia lacked accurate recent national estimates of blindness and low vision. Therefore, prevention and control programs face serious problem of lack of recognition of the problem and challenges in tracking achievements towards program goals. Objective: To determine the prevalence of blindness and low vision at the national and regional levels in Ethiopia. Method: A national survey was conducted on a representative population in all nine regional states and two city administrations of the country. The LogMar chart was used to determine the presenting visual acuity and ophthalmologists determined the primary cause of low vision and blindness. Results: Based on the assessment of the presenting visual acuity, the national prevalence of blindness is 1.6% (1.1% for urban and 1.6% for rural populations) and that of low vision is 3.7% (2.6% for urban and 3.8% for rural populations). Blindness and Low vision are more prevalent among females. The major causes of blindness are cataract and trachomatous corneal opacity. The major causes of low vision are cataract and refractive error. Prevalence of childhood blindness is 0.1% and accounts for over 6% of the total blindness burden in Ethiopia. The national prevalence of Bitot\'s spots is 0.7%. Conclusion: Blindness and low vision are major public health problems in Ethiopia. The large proportion of low vision (91.2%) and blindness (87.4%) are due to avoidable (either preventable or treatable) causes. Females and rural residents carry greater risk for eye problems. Adequate emphasis needs to be given to prevent blindness among children and avert millions of years of unnecessary blindness. Recognizing the severity of the magnitude of eye problems (blindness and low vision) and enhancing the government commitment to improve the situation is critical. Ethiopian Journal of Health Development Vol. 21 (3) 2007: pp. 204-210
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