Optimization of received power and SNR for an indoor attocells network in visible light communication

White LEDs Visible Light Communication (VLC) is applied in communication and illumination simultaneously. It provides unrestrained frequency spectrum and a large bandwidth that produces a higher transmission rate and speed in short-range communication. Also, VLC was considered as a promising alternative technology to the radio frequency in the next generation of communication systems. In this paper, the optical attocells configuration and LEDs distribution are proposed for optimizing the received power and Signal-to-Noise Ratio (SNR) in the Line of Sight (LOS) propagation link. Besides that, the trade-off between minimum SNR and received power are investigated. The simulation results showed that the proposed model can save 6.25% of the total transmitted power, and the optical received power versus semi-angle and field of view have with about increased 16.5% and 27.54% respectively. Moreover, the SNR also has 7.4% improvement. Hence, the proposed configuration model has improved the performance of VLC systems and has widen the window for future improvement

Religious Nationalism in the Kurdistan Region of Iraq

This thesis explores a new political phenomenon in the Middle East - the reconciliation of nationalism and Islamism by Islamic political parties in the context of nation states. Although the concept of religious nationalism has been discussed substantially before, as for example in Juergensmeyer (1993: 40) where the author defines religious nationalism as “the attempt to link religion and the nation-state”, this work highlights that a new brand of religious nationalism has emerged in the Middle East as the result of the intertwining of nationalism and Islamism. The focus of this study is, therefore, on the development of religious nationalism in the continuously tumultuous region of the Middle East. The aim of this researchis to investigate whether Islamism in Kurdistan is limited by the politics of nationalism, which is an accentuated example for the whole Middle East region. Furthermore, it should be noted that many of the religious nationalists themselves have not yet fully acknowledged the existence of the trend of merging between Islamism and nationalism. For instance, although the position of the Muslim Brotherhood of Kuwait, during the liberation of their state from the Iraqi regime, is a clear example of religious nationalism, all other affiliations of this organisation around the world at that time viewed the military operation as a foreign occupation. Highlighting this historical juncture in the political life of the Middle East by studying the Islamism in the Kurdistan region helped to elaborate on this new type of politics exceptionally well. This is essentially due to the absence of a politically recognised nation state which renders Kurds to be particularly susceptible to various manifestations of nationalism. The key finding of this project was, therefore, the notion that Islamism in Kurdistan has become significantly framed by the politics of nationalism

Soil, location, and climatic factors influencing available phosphorus level with depth in subsoil horizons of Iowa soils

Objectives of this dissertation research were: (1) to develop multiple regression equations to predict available (Bray-1) P levels at various subsoil depths, using soil horizon, soil profile, parent material, location, and climatic variables; (2) to develop prediction equations for subsoil P without the soil horizon variables; and (3) to compare location (legal township and range numbers) and climatic variables (mean annual precipitation and temperature) for predicting subsoil P. Input data were from 3913 soil horizons from 696 soil profiles from 22 Iowa counties representing the most soil association areas;The depth to each horizon variable was included in all regressions. Soil horizons variables included pH, soil test P (dependent variable), soil test K, clay, organic carbon, and bulk density. Parent material variables included loess, pedisediment materials above till, till and paleosol, colluvium in loess areas, alluvium in loess and till areas, and eolian sands. Profile variables included genetic horizon, site slope, thickness of A horizon, minimum pH, depth to minimum pH, drainage class, biosequence, and depth to maximum clay horizon;Variables were initially selected in alternate models including linear functions of parent material variables, cubic function of depth, and quadratic functions of all others. Climatic variables, more important than location variables, were retained. Significant interactions between linear, quadratic, and other variables and then interactions between other variables were then selected. Three final prediction models were selected from (1) all variable groups (88 variates, R(\u272) = 0.776), (2) all except horizon variables (81 variates, R(\u272) = 0.745), and (3) all except horizon and genetic horizon variables (75 variates, R(\u272) = 0.719). Appropriate final model depends on availability of horizon data and soil profile descriptions;The final all-variable prediction model (MODEL M-6) for subsoil P (STP) included 18 linear, 7 quadratic, 1 cubic, and 62 interaction variates (15 DEPTH*X(,i), 9 DEPTH(\u272)*X(,i), 2 DEPTH(\u273)*X(,i), and 36 linear*linear interactions between other variables. Effects of the variables on STP were examined in MODEL M-6 using partial derivatives of STP with respect to the X(,i) variables and by computing predicted STP values for depth and combinations of two other variables from simplified regression equations. The dominant effects of biosequence modified by interactions with the cubic function of depth and many other variables and the joint effects of pH and bulk density with depth on STP showed that MODEL M-6 can predict widely varying STP distributions. Effects of other variables on STP distributions were also shown

An evaluation of reflective practice as experienced by TESOL teachers in a Saudi academic institution

Reflective practice is a strategy which can contribute to the development of TESOL teachers’ professionalism (Azizah et al., 2018). Previous research (Constantinou, 2009; Yassaei, 2011; Farrell & Mom, 2015) has found that TESOL teachers have recognised its usefulness. The aim of this qualitative study is to explore the experience of reflective practice amongst TESOL teachers working in the English Language Centre (ELC) of the Saudi university where a reflective practice framework had not previously been used (Melibari, 2016).This research examines a 13-week reflective practice programme with 12 teacher- participants. Through a critical incident approach, they were invited to reflect on critical events by writing in reflective journals (Richards and Farrell, 2005) and through collaborative reflective practice.During the intervention of the study, semi-structured interviews, along with the reflective journals, provided the data for this study. A second set of interviews (post intervention) was conducted six months after the reflective practice programme concluded to evaluate its impact and potential sustainability.The analysis identified four superordinate themes: (1) the meaning of reflective practice; (2) factors that were influential in the experience; (3) collaborative reflective practice and (4) the impact of reflective practice. Participants exhibited self-motivation to experience reflective practice; they also expressed frustration towards barriers to integrating reflective practice into their institution. Seven teachers, nonetheless, maintained their reflective practice over time and valued the collaborative aspect encouraged by reflective group meetings.The interpretative phenomenological analysis (IPA) approach was utilised to analyse the data. The IPA framework enables the study to highlight the impact of reflective practice on the development of a community of practice (CoP) through which knowledge was shared and extended, teachers’ beliefs were articulated through reflection and a new understanding of professional practice was fostered. The study also contributes new data to the IPA body of research, alongside TESOL-specific examples of reflective practice data.Finally, the study identifies its limitations, offers recommendations for integrating reflective practice into teachers’ continuing professional development and presents suggestions for further research

Dimethyl Sulfoxide (DMSO) has an Additive Effect and Alters Minimal Inhibitory Concentrations of Antifungal Drugs

Background: Dimethyl sulfoxide (DMSO) iscommonly used as a solvent for anti-fungal drugs. It hasbeen reported to possess anti-fungal activity by itself somay interfere in the evaluation and comparison of antifungaldrugs. DMSO 1% and below are usually consideredto possess insignificant effect on the growth of fungi. Thepresent study was aimed to determine anyadditive/synergistic effect of DMSO (1%) with anti-fungaldrugs.Methods: The effect of DMSO (1%) was determined onthe colonial growth of Trichophyton rubrum, andMicrosporum canis along with clotrimazole, griseofulvin,ketoconazole and thymoquinone (an active principle ofNigella sativa). Similarly, the ability of DMSO (1%) toenhance the effect of amphotericin-B and thymoquinonewas observed on the growth of Aspergillus niger. The fungiwere grown in three sets of plates of dermasel agar foreach drug containing: (a) serial dilutions of the drug alone;(b) serial dilutions of the drug plus DMSO 1% in eachdilution and (c) dermasel agar alone, as control.Results: DMSO (1%) lowered the MICs of all drugstested against the fungi used, except amphotericin-Bagainst Aspergillus niger. Presence of DMSO (1%) in serialdilutions of drugs also significantly shifted the growthcurves of fungi towards right.Conclusion: DMSO, as a solvent, is one of theimportant factors that can alter the results of antifungaldrugs

Burden of common mental disorders in patients with functional dyspepsia

OBJECTIVE: To assess the frequency of common mental disorders among diagnosed functional dyspepsia patients.METHODS: A case-control study with 150 cases of functional dyspepsia (FD) and 150 healthy controls were recruited from Gastroenterology Clinic at the Aga Khan University Hospital Karachi from 1st March 2009 through 31st August 2009. Urdu version of WHO-developed Self-Reporting Questionnaire (SRQ) was administered to diagnose patients of FD and healthy controls. A cut off score of 8 on SRQ was used to confirm cases of Common mental disorders (CMD). Data was entered and analyzed by SPSS version 16.0.RESULT: There was significant difference in CMD i.e. 107 (71.33%) versus 23 (15.33%) in cases and controls respectively (p

Lean-excellence business management for manufacturing SMEs focusing on KRI

Purpose The purpose of this paper is to develop an effective framework for implementing Lean strategies in small- and medium-sized enterprises (SMEs) in the Kurdistan Region of Iraq (KRI). Design/methodology/approach Based on the integration of LM tools and techniques with the Malcolm Baldrige National Quality Award (MBNQA) criteria a systematic Lean implementation framework for manufacturing SMEs has been proposed. The core values, drivers and tools of the proposed framework were further developed based on case studies in three SMEs in the KRI. Findings Proposed framework is able to provide a simple pathway for SMEs to systematically implement Lean techniques in seven functional areas in order to create Lean culture in the organisation. Business performance measurement in terms of profitability, customer satisfaction, employee’s satisfaction, competitiveness growth and ergonomic improvement is presented in favour of evaluating Lean outcomes appropriately. It also presents the experience of small firms in implementing Lean programmes to show that Lean is valid in SMEs. Research limitations/implications The framework concentrates only on the internal issues of the organisation, while external variables such as national culture and external support are excluded. Practical implications The framework assists improvements in SMEs that either initially attempt to start Lean journey or those that are at more advanced levels towards excellent-Lean manufacturing. The framework can also be used as a self-assessment model to determine the degree of Lean readiness. Originality/value To the best knowledge of the author, it is the first framework that integrates Lean techniques with MBNQA criteria to support Lean implementation in SMEs. It is also the first study regarding Lean-excellence in the KRI.Published onlin

Mathematical modelling of permanent-magnet brushless DC motor drives

Brushless dc motor drives have become increasingly popular, following recent developments in rare-earth permanent-magnet materials and the semiconductor devices used to control the stator input power and to sense the rotor position. They are now frequently used in applications such as flight control systems and robot actuators, and for drives which require high reliability, long life, little maintenance and a high torque-to-weight ratio. In many motor drives the presence of torque and speed ripples, especially at low speed, is extremely undesirable. The mathematical model developed in this thesis was used to investigate their occurrence in a typical brushless dc drive system, with the objective of establishing factors which effect their magnitude and ways by which they may be reduced. The model is based on the numerical solution of the differential equations for the system, with those for the motor being formulated in the phase reference frame. Tensor methods are used to account for both the varying topology and the discontinuous operation of the motor arising from changes in the conduction pattern of the inverter supply switches. The thesis describes the design, construction and testing of an experimental voltage source PWM inverter, using MOSFET switching devices, to drive a 1.3 kW 3-phase brushless dc motor. A practical circuit is described which implements current profiling to minimize torque ripple, and the optimum phase current waveforms are established. The effect of changes in the firing angle of the inverter switches on the torque ripple are also examined. Throughout the thesis, theoretical predictions are verified by comparison with experimental results