Electrical power generation through concentrated solar technology for the southern cities of Iraq

With a continuing mismatch between generating capacity and demand requirements, Iraqi cities are still enduring scheduled power outages. In this work, concentrated solar power (CSP) technology is proposed and designed for Iraqi cities to inject power into distribution networks with the objective of boosting the generating power capacity. Since CSP systems require a preliminary study of the direct normal irradiance (DNI), analyses of monthly data is carried out for each of the candidate cities. This is followed by determination of the amount of solar irradiance that falls on a titled collector per month considering the effects of reflection and diffusion. Finally, a thermal power plant is proposed and simulated using the system advisory model (SAM) per city. Results presented show an encouraging number of metrics and confirm the feasibility of such a plant in southern Iraq. The levelised cost of electricity and capacity factor shows a considerable decrease and increase respectively, when the plant is backed up by a fossil fuel steam cycle under circumstances when a plant loses over 80% of the MW capacity due to drop in solar irradiance. To provide a comparision platform, for each city, a photovolitaic (PV) plant is designed with an indentical electric capacity to that of the CSP plant. Findings from this work confirm that CSP plants can provide a suitstanable and enviroemntl friendly solution to electrical power shortages in the country compared to the current PV trends

A secure image steganography based on burrows wheeler transform and dynamic bit embedding

In modern public communication networks, digital data is massively transmitted through the internet with a high risk of data piracy. Steganography is a technique used to transmit data without arousing suspicion of secret data existence.  In this paper, a color image steganography technique is proposed in spatial domain. The cover image is segmented into non-overlapping blocks which are scattered among image size window using Burrows Wheeler transform before embedding. Secret data is embedded in each block according to its sequence in the Burrows Wheeler transform output. The hiding method is an operation of an exclusive-or between a virtual bit which is generated from the most significant bit and the least significant bits of the cover pixel. Results of the algorithm are analyzed according to its degradation of the output image and embedding capacity. The results are also compared with other existing methods

Capacitor current analysis of a three-level neutral point clamped converter under unbalanced loading conditions

A neutral point clamped (NPC) converter is considered a forefront in industrial applications. Supplying a typically balanced stand-alone load is one of those applications. However, the loading may become unbalanced which can impact the capacitors’ current and voltage ripple. In this work, an approach is proposed that analyze the capacitor current under unbalanced loading. The proposed method is based on a combination of two-dimensional Fourier series and symmetrical components. Since, two-dimensional Fourier series sectorize the spectrum into harmonics that are either defined by multiples of, fundamental, carrier or both frequencies, the method derives the Fourier coefficients for each sector, corresponding to a sequence current. Therefore, based on the presented approach, each harmonic amplitude in the spectrum sector is defined by three Fourier coefficients reflecting zero, positive and negative sequence current. The capacitor current spectrum is obtained by vector summing sequence coefficients. The method is tested on unbalanced load conditions with (out) a ground path. Results verify feasibility of the proposed method in deriving Fourier coefficients of capacitor currents that accurately reflects the loading status of the NPC. This is vital for converter design in terms of proper sizing of DC capacitor and can help in avoiding components failure

Design And Performance Of Laser Structures Based On Group III-Nitrides [QC689.55.S45 T363 2008 f rb].

Simulasi peranti bagi ciri elektrik, optik dan terma diod-diod laser (LDs) berasaskan GaN telah dikaji. Bagi laser-laser sedemikian adalah susah memperolehi lapisan penutup-p yang mempunyai ketebalan yang mencukupi, Device simulations for the electrical, optical and thermal characteristics of GaN-based laser diodes (LDs) have been investigated. It is difficult to obtain pcladding layers with sufficient thickness of high Al composition and high acceptor concentration

Analysis of Five Level Neutral Point Clamped Inverter Fed from 18 Pulse ‎Output Multiphase Rectifier for Grid Tied Applications

 تلعب محولات إلكترونيات الطاقة دورًا رئيسيًا في تطبيقات معالجة الطاقة المختلفة. في كثير من الحالات ، تنشأ الحاجة إلى استخدام محولين لتحقيق معالجة الطاقة أو التكييف أو كليهما. في هذا العمل ، تمت دراسة نظام محولين يعتمد على محولين متعدد الأطوار / متعدد المستويات. الهدف الرئيسي هو معالجة طاقة التيار المتناوب من مصدر يمكن أن يكون مصدر طاقة موزع (DER) عن طريق تحويله إلى تيار مستمر قبل حقنه في نظام تيار متردد آخر. يتم استخدام مقوم متعدد الأطوار ذو 18 نبضة للهدف الأول. يتم تحقيق مهمة المعالجة الثانية ، والتي تتضمن تحويل طاقة التيار المستمر إلى التيار المتناوب من خلال محول محايد ذو خمسة مستويات مثبتة .(NPC)  النتائج المبينة تحقق فوائد المعدل متعدد الأطوار في إنتاج جهد تيار مستمر سلس. ومن جانب أخر ، تتميز NPC ذات المستويات الخمسة بميزة مثيرة للاهتمام وهي ان الجهد الأساسي ذو قيمة عالية.Power electronics converters play a major role in various energy processing applications. In many instances the need arises to use two converters to achieve power processing, conditioning or both. In this work, two converter systems are studied, which is based on two multiphase/multilevel converters. The main objective is to process AC power from a source which can be a distributed energy source (DER) by converting it to DC before injecting it into another AC system. An 18 pulse multiphase rectifier is used for the first objective. The second processing task, which involves converting the DC power back to AC is achieved by five level neutral point clamped converter (NPC). Results verify the benefits of the multiphase rectifier in producing a smooth DC voltage. On the other side, the five level NPC revels an interesting feature of high fundamental voltage

Molecular Detection of Extended-Spectrum Beta- Lactamases inClinical Isolates of Acinetobacterbaumannii

Resistance to third-generation oxyimino cephalosporins is emerging, and it is considered a problem in medical field. Extended spectrum ?-lactamase (ESBL) producing Acinetobacter baumannii have been noticed to be important cause of hospital infections. This study aimed to undertaken and determinethe occurrence of ESBLs especially SHV, TEM and VEB ?-lactamase types. A total of 770 clinical samples were collected from February to June, 2011. TheA. baumanniiisolates were identified according to API 20NE system. Phenotypic detection of ESBL was performed by using the combination disk, disk approximation  methods then confirmed by culturing on  ESBL CHROM agar medium.  The isolates were subjected to polymerase chain reaction (PCR) assays with specific primers for blaSHV, blaTEM and  blaVEB. Twelve (1.5%) A. baumanniiisolates were recovered from clinical infections. All of them were ?-lactam resistant (resistant to both ampicillin and amoxicillin). Of the ?-lactam resistant isolates, 8/12 (66.7%)were found to be disk combination test positive, and 10 (83.3%) isolates were confirmed as ESBL producers and gave heavy growth on ESBL CHROM agar. In PCR experiments using specific primers for blaSHV, blaTEM and  blaVEB genes, out of 12 A. baumanniiisolates, three (25%) were harbored blaSHV gene and only one (8.3%) isolate gave positive PCR results for blaTEM gene. This study demonstrate all isolates were blaVEB negative. The present study concluded that the emerging of dissemination of ESBL producing A. baumannii in Najaf hospitals. Keywords:key words,Acinetobacterbaumannii , Extended-Spectrum Beta- Lactamases, Molecular Detectio

Al0.15Ga0.85N/GaN Heterostructure Field Effect Transistors (HFET)Device Structure Optimization And Thermal Effects.

Al0.15Ga0.85N/GaN heterostructure field effect transistors (HFETs) was simulated by using ISETCAD software with varying substrate type, gate length and source drain resistances

Between tradition and modernity: determining spatial systems of privacy in the domestic architecture of contemporary Iraq

The notion of privacy represents a central criterion for both indoor and outdoor social spaces in most traditional Arab settlements. This paper investigates privacy and everyday life as determinants of the physical properties of the built and urban fabric and will study their impact on traditional settlements and architecture of the home in the contemporary Iraqi city. It illustrates the relationship between socio-cultural aspects of public/private realms using the notion of the social sphere as an investigative tool of the concept of social space in Iraqi houses and local communities (Mahalla). This paper reports that in spite of the impact of other factors in articulating built forms, privacy embodies the primary role under the effects of Islamic rules, principles and culture. The crucial problem is the underestimation of traditional inherited values through opening social spaces to the outside that giving unlimited accesses to the indoor social environment creating many problems with regard to privacy and communal social integration

Growth and Characterization of High-Quality GaN Nanowires on PZnO and PGaN by Thermal Evaporation

In the current research, an easy and inexpensive method is used to synthesize highly crystalline gallium nitride (GaN) nanowires (NWs) on two different substrates [i.e., porous zinc oxide (PZnO) and porous gallium nitride (PGaN)] on Si (111) wafer by thermal evaporation without any catalyst. Microstructural studies by scanning electron microscopy and transmission electron microscope measurements reveal the role of the substrates in the nucleation and alignment of the GaN NWs. Further structural and optical characterizations were performed using high-resolution X-ray diffraction, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. Results indicate that the NWs have a single-crystal hexagonal GaN structure and growth direction in the (0001) plane. The quality and density of GaN NWs grown on different substrates are highly dependent on the lattice mismatch between the NWs and their substrates. Results indicate that NWs grown on PGaN have better quality and higher density compared to NWs on PZnO