Directive ultra wideband antenna for medical applications

Since the acceptance of unlicensed band of Ultra-Wideband (UWB) technology in the range between 3.1 and 10.6 GHz, the realization of low-cost UWB wireless systems is considered a fundamental research goal both for military and commercial applications. The possible use and benefits of UWB technology are significant among its potential applications, high-resolution radar and short-range ultra-high speed data transmission. However, one of the most critical challenging task of the UWB system is the designing of a compact size antenna that possess a good gain and high directivity. Thus, the aim of this project is to design and develop a directive and miniaturized antenna for UWB applications. The antenna is designed and fabricated on a Flame Retardant (FR4) laminated substrate with dielectric constant, ԑr of 4.3 and thickness of 1.6mm. Several numbers of antennas have been carried out throughout the completion of the project. Firstly, an antenna with slots on radiator has been designed. Subsequently, Ground Defected Structure (DGS) is implemented. For increasing bandwidth and impedance matching of the first antenna, thus an antenna with compact dimension of 25×45mm2 has been resulted. Finally, a reflector structure with the distance of 18mm is added for directivity and gain enhancement. The antenna with reflector has been fabricated using etching technique and being measured for the reflection coefficient. As the result, by applying reflector, the directivity and gain of the antenna has increased significantly, from 5.81dBi to 7.06dBi. This showed 21.52% gain improvement of the proposed antenna by implementing reflector. Therefore, the proposed antenna which has compact size and high gain is seen as a suitable candidate for the use of UWB applications

Stomach Content Analysis of Feed and Feeding Habit of Oreochromis Niloticus Fish Species in Baro-Akobo Basin, South West Ethiopia in Case of Alwero Dam

The food and feeding habit of Oreochromis niloticus inhabiting Alwero dam water body was investigated. This study was carried out to identify the type and availability of food consumed by fish. Two hundred fifty fish were obtained from the reservoir during wet and dry season. Total length (TL; cm) and Total weight (TW; g) of each fish was measured. The fish body was dissected and the entire gut was removed. The stomachs were opened and its content was poured on a petridish and stirred with water drops. The food materials were identified visually and using microscope. The fish sizes ranged between 26.5 to 39cm (TL) and 390 – 1400g (TW). More than quarters of the fish caught in Alwero dam have (80.4%) full and (19.6%) empty stomach. The study reveals the importance of zooplankton (34%), fish remain (27), phytoplankton (22%), insect part and mud /sand (8%) form important items in the diet of this species. Size based differences were showed highly significance by shifting of their feeding behavior from eating zooplankton to phytoplankton as size increased and seasonal availability was additional factor for ontogenetic shift. Morphometric relationship of total weight and total length were showed a linear relationship indicating effect of length over weight and vice versa. Keywords: Nile tilapia, Oreochromis niloticus, food and feeding, zooplankton, Alwero dam. DOI: 10.7176/JBAH/11-3-01 Publication date: February 28th 202

Perceptions of Court Appointed Special Advocates on Volunteer Turnover

There is a high turnover rate among court-appointed special advocates (CASA) in the United States. The purpose of this qualitative case study was to explore the perception of the retention of CASA volunteers. Maslach\u27s burnout theory and Greene\u27s theory of resilience provided the framework for the study. A sample of9 active and 5 inactive CASA volunteers, one CASA volunteer recruiter, 3 program supervisors, and one administrator were interviewed. The data was organized and coded manually to facilitate auto-coding using qualitative data software. All responses to each question were compiled in one place allowing for thematic analysis based on the frequency of terms and concepts occurring during the interviews. According to study findings, lengthy and complicated processes, restrictive laws and regulations, limited outcomes impact for the children, and unrealistic expectations of the CASA volunteers were the main reasons for the high turnover rate. Support and preparedness were crucial in the CASA volunteers\u27 decision to serve longer. The study findings would be available for decision makers to review and revise policies in order to improve the experience and adjust expectations imposed on CASA volunteers via recruitment and training messaging. Increasing CASA volunteers\u27 retention rate would change the trajectory of more children in foster care by improving their chances for achieving positive outcomes

Impacts of Using Paralanguage on Teaching and Learning English Language to Convey Effective Meaning

Paralanguage is considered as an influential factor in foreign language teaching and learning that plays an essential role in language teaching and enhancing language learners’ performance. The paper states to explore the effect of using paralanguage on teaching and learning English language to EFL learners. It is going to investigate the relationship between learners’ awareness of learning concept and teachers’ paralanguage; the standardized testing relational aspect between students’ learning and teachers’ paralanguage; and the learners’ credible teaching perceptions depend on the teachers’ paralanguage. The participants in this research are teachers and students of English language in the College of Science and Arts, Almandaq Branch in Albaha University. The study has concluded that paralanguage strategies assist in communicating effective meanings. It is recommended that EFL teachers and learners should use paralanguage strategies in their teaching and learning processes to convey meaning effectively

L'IMPACT DE LA PARTICIPATION BUDGETAIRE ET DE L'INCERTITUDE ENVIRONNEMENTALE SUR LA PERFORMANCE ET LA SATISFACTION AU TRAVAIL

En adoptant la théorie de contingence, la présente étude examine l'impact de la participation budgétaire et de l'incertitude environnementale sur la performance et la satisfaction au travail. Cinquante trois managers appartenant à trente entreprises industrielles tunisiennes ont participé à cette étude. La collecte des données a été faite via une enquête par questionnaire. Les résultats mettent en évidence un effet modérateur positif de l'incertitude environnementale sur la relation entre la participation budgétaire et la performance et la satisfaction au travail. Ainsi, nos résultats suggèrent qu'il est nécessaire que les entreprises industrielles encouragent la participation des managers dans le processus budgétaire, surtout dans le contexte actuel de la Tunisie qui se caractérise par un degré important d'incertitude de l'environnement.Participation budgétaire, performance managériale, satisfaction au travail, incertitude environnementale

Properties of PMMA Bone Cement Modified with Nano-hydroxyapatite and Acetone

Fracture in the adjacent levels is one of the consequences to the use of commercial poly methylmethacrylate (PMMA) bone cement. Modified PMMA with a reduced Young’s modulus was found to be safer for cancellous bone augmentation procedures. The aim of this research was to study the effect of adding hydroxyapatite (HA) nano-particles and acetone on different properties of PMMA cement. A commercial PMMA cement was used as a model for bone cement. Three groups of modified PMMA/nano-HA were investigated by adding 2, 4 and 6 wt. % of HA. Acetone as a porogen mixed with distilled water in different amounts (A/W: 1:1, 2:1.5 and 2:1g) was used to produce porous PMMA cement. The residual monomer, polymerization and mechanical properties under tension and compression tests were investigated. Young’s modulus detected from compression test decreased from 826.5±10 to 728±66 MPa by adding 6wt.% HA. Adding acetone to PMMA with 2:1.5g (A/W) has decreased the compressive Young’s modulus to 753±38 MPa. High Performance Liquid Chromatography (HPLC) measurements were carried out with intervals of 2 hours, 6 hours and 24 hours to evaluate the residual monomer for all groups. The amount of residual monomer has decreased after 24 hours of curing by adding acetone and nano-HA. Modifying PMMA by HA and acetone have inconsistent effect on the polymerization temperature. It was concluded that HA and acetone can be used to reduce the stiffness and residual monomer with enhanced biocompatibility of the commercial PMMA bone cement