149 research outputs found

    Adaptation Of Istisna’a And Ijara'h Into The Conceptualization Of Ips In The Malaysia Construction Industry

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    Permintaan projek yang bertambah telah mendorong industri pembinaan Malaysia untuk menggunakan pelbagai jenis sistem pemerolehan seperti “Design and Build” dan “Project Management Consultancy”. Bagaimanapun, kekurangan ketelusan, kualiti kemahiran yang rendah, risiko, pertikaian, kekurangan keupayaan dan masalah berkaitan pengurusan ialah antara beberapa halangan yang dikenal pasti mempunyai kaitan dengan sistem pemerolehan semasa yang digunakan di industri pembinaan Malaysia. Penyelidikan ini bagaimanapun dijalankan untuk menyediakan satu sistem pemerolehan Islam alternatif yang akan menangani masalah-masalah yang dikenalpasti. Maka, penyelidikan ini dilaksanakan bagi mencapai objektif berikut: Pertama, penyelidikan ini akan menilai penggunaan sistem-sistem pemerolehan yang diamalkan di industri pembinaan Malaysia; Kedua, mengenal pasti masalah utama dalam sistem pemerolehan yang diamalkan dalam industri pembinaan Malaysia; Ketiga, mengulas kemungkinan kebolehgunaan Istisna'a and Ijara'h dalam sistem pemerolehan pembinaan akan dijalankan; Keempat, satu sistem pemerolehan Islam dalam industri pembinaan Malaysia ditentukan; dan kelima, sistem pemerolehan Islam dalam industri pembinaan Malaysia dikonsepsikan. The increasing project demands have driven Malaysian construction industry to embrace various modern types of procurement system such as Design and Build and Project Management Consultancy. However, lack of transparency, low quality of workmanship, risk, dispute, lack of capability and management-related problems are some of the setbacks identified to be associated with the current procurement system used in the Malaysian construction industry. This research was therefore conducted to provide an alternative Islamic procurement system that would address the identified problems. Hence, this research is implemented to achieve the following objectives: first, this research will evaluate the usage of procurement systems practised in Malaysian construction industry; second, to identify the major problems in procurement systems practised in Malaysian construction industry were identified ; third, the review on the applicability of Istisna’a and Ijara’h in construction procurement system were conducted; fourth, the need for an Islamic procurement system in Malaysian construction industry were determined; and fifth, the Islamic procurement system in Malaysian construction industry were conceptualised

    Modified variable step-size incremental conductance MPPT technique for photovoltaic systems

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    A highly efficient photovoltaic (PV) system requires a maximum power point tracker to extract peak power from PV modules. The conventional variable step-size incremental conductance (INC) maximum power point tracking (MPPT) technique has two main drawbacks. First, it uses a pre-set scaling factor, which requires manual tuning under different irradiance levels. Second, it adapts the slope of the PV characteristics curve to vary the step-size, which means any small changes in PV module voltage will significantly increase the overall step-size. Subsequently, it deviates the operating point away from the actual reference. In this paper, a new modified variable step-size INC algorithm is proposed to address the aforementioned problems. The proposed algorithm consists of two parts, namely autonomous scaling factor and slope angle variation algorithm. The autonomous scaling factor continuously adjusts the step-size without using a pre-set constant to control the trade-off between convergence speed and tracking precision. The slope angle variation algorithm mitigates the impact of PV voltage change, especially during variable irradiance conditions to improve the MPPT efficiency. The theoretical investigations of the new technique are carried out while its practicability is confirmed by simulation and experimental results

    Multi-parametric arterial spin labelling and diffusion-weighted magnetic resonance imaging in differentiation of grade II and grade III gliomas

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    Purpose: To assess arterial spin labelling (ASL) perfusion and diffusion MR imaging (DWI) in the differentiation of grade II from grade III gliomas. Material and methods: A prospective cohort study was done on 36 patients (20 male and 16 female) with diffuse gliomas, who underwent ASL and DWI. Diffuse gliomas were classified into grade II and grade III. Calculation of tumoural blood flow (TBF) and apparent diffusion coefficient (ADC) of the tumoral and peritumoural regions was made. The ROC curve was drawn to differentiate grade II from grade III gliomas. Results: There was a significant difference in TBF of tumoural and peritumoural regions of grade II and III gliomas (p = 0.02 and p =0.001, respectively). Selection of 26.1 and 14.8 ml/100 g/min as the cut-off for TBF of tumoural and peritumoural regions differentiated between both groups with area under curve (AUC) of 0.69 and 0.957, and accuracy of 77.8% and 88.9%, respectively. There was small but significant difference in the ADC of tumoural and peritumoural regions between grade II and III gliomas (p = 0.02 for both). The selection of 1.06 and 1.36 × 10-3 mm2/s as the cut-off of ADC of tumoural and peritumoural regions was made, to differentiate grade II from III with AUC of 0.701 and 0.748, and accuracy of 80.6% and 80.6%, respectively. Combined TBF and ADC of tumoural regions revealed an AUC of 0.808 and accuracy of 72.7%. Combined TBF and ADC for peritumoural regions revealed an AUC of 0.96 and accuracy of 94.4%. Conclusion: TBF and ADC of tumoural and peritumoural regions are accurate non-invasive methods of differentiation of grade II from grade III gliomas

    Improved performance low-cost incremental conductance PV MPPT technique

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    Variable-step incremental conductance (Inc.Cond.) technique, for photovoltaic (PV) maximum power point tracking, has merits of good tracking accuracy and fast convergence speed. Yet, it lacks simplicity in its implementation due to the mathematical division computations involved in its algorithm structure. Furthermore, the conventional variable step-size, based on the division of the PV module power change by the PV voltage change, encounters steadystate power oscillations and dynamic problems especially under sudden environmental changes. In this study, an enhancement is introduced to Inc.Cond. algorithm in order to entirely eliminate the division calculations involved in its structure. Hence, algorithm implementation complexity is minimised enabling the utilisation of low-cost microcontrollers to cut down system cost. Moreover, the required real processing time is reduced, thus sampling rate can be improved to fasten system response during sudden changes. Regarding the applied step-size, a modified variable-step size, which depends solely on PV power, is proposed. The latter achieves enhanced transient performance with minimal steady-state power oscillations around the MPP even under partial shading. For proposed technique's validation, simulation work is carried out and an experimental set up is implemented in which ARDUINO Uno board, based on low-cost Atmega328 microcontroller, is employed

    Power Quality and System Stability Impact of Large-Scale Distributed Generation on the Distribution Network: Case Study of 60 MW Derna Wind Farm

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    Wind energy (WE) has become one of the most promising and developed forms of renewable energy source due to its efficiency and the availability of different capacities according to the loading requirements. The integration of wind turbines in the Libyan network has become an indispensable choice due to Libya’s distinguished location and for the Libyan National Initiative. Despite the numerous benefits of WE, the penetration of WE sources in the distribution network has some negative impacts related to the quality and reliability of the electric power supplied to the network. Owing to, the intermittent nature of these sources and electronic circuits needed to regulate the extracted power to comply with the grid requirements. In this chapter, implementation of the eastern Libyan network in NEPLAN and MATLAB/SIMULINK packages are carried out to investigate and analyze the significance of wind farm penetration in the medium voltage level of Libyan Distribution Network. A 60 MVA wind farm system has been connected to the Libyan distribution network according to the Libyan National Initiative. Different penetration scenarios are simulated to testify the technical aspects of integrating WE on the distribution level

    Anti-Müllerian hormone and response to ovulation induction with clomiphene citrate in women with polycystic ovary syndrome

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    Background: Anti-Müllerian hormone (AMH) is suggested as an important marker for women with polycystic ovary disease (PCOS). Several studies have found serum level of AMH correlate well to ovarian response to ovulation induction in women with PCOS. This study was conducted to assess the relationship between AMH in women with PCOS and response to ovulation induction with clomiphene citrate.Methods: Prospective observational cohort study conducted at Ain-Shams university maternity hospital from February 2013 to February 2014. 100 women with PCOS were recruited from the infertility outpatient clinic. Serum AMH levels were measured by enzyme linked immunosorbent assay in the early follicular phase (days 3-5). Ovulation induction by clomiphene citrate was started on day 5 as 50 mg daily tablet for 5 days. Ovulation was documented by transvaginal ultrasonography and women who failed to ovulate till day 35 were considered anovulatory.Results: 72 women ovulated within 12 to 33 days of the menstrual cycle, while 28 had undetectable ovulation till day 35. The median serum AMH level was significantly higher in women with failed ovulation [4.05 ng/mL (3.7 - 4.4)] than in ovulating women [2.7 ng/mL (1.9 - 3.1)] (p<0.001). Receiver-operating characteristic (ROC) curve analysis found the best cutoff value of AMH for prediction of successful ovulation ≤3.6 ng/mL (sensitivity = 97.2%, specificity = 82.1%).Conclusions: Anti-Müllerian hormone is a very useful predictor of poor responders to clomiphene citrate among women with polycystic ovary disease

    Assessment of Infertility Factors and Their Relative Impact in Pregnancy using Ultrasonography & Hormonal Checkup

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    Infertility as a social and psychological problem among middle east natives. Among them, Transvaginal ultrasound (TVU) and hormonal tests have been selected to evaluate infertility in this study. The objective was to assess the infertility factors and their relative impact in pregnancy and to deduce the equation to predict infertility. Methods: a retrospective data (morphometric pathologies of uterus and ovaries using TVU and laboratory hormones (FSH, LH)) have been collected from clinics for 180 women of reproductive age (15-49 years) in Sudan.  The data analyzed by SPSS. The results showed that there were 120 (66.7%) infertile and 60 (33.3%) fertile ladies based on the marriage date. The common ovarian causes of infertility were the polycystic ovary (PCOs) 23.3%, simple cyst 6.1%, hemorrhagic cyst, 4.4%, and uterus causes: 6.7% intramural fibroma, 6.1% retroverted uterus, 2.8% submural fibroma, 2.2 polyps. The general accuracy of Stepwise Linear Discriminant Analysis (SLDA) was 78.9%, for infertile was 70.8% and for fertile 95%. Larger ovarian width indicates significance (p smaller than 0.05) infertility and FSH level low among infertile ladies, but LH is less dependent on discriminatio

    C-Abl inhibition; a novel therapeutic target for Parkinson’s disease

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    Parkinson’s disease (PD) is the most prevalent movement disorder in the world. The major pathological hallmarks of PD are death of dopaminergic neurons and the formation of Lewy bodies. At the moment, there is no cure for PD; current treatments are symptomatic. Investigators are searching for neuroprotective agents and disease modifying strategies to slow the progress of PD. However, recently, due to the ignorance of the main pathological sequence of PD, many drug targets failed to provide neuroprotective effects in human trials. Currently, a huge amount of evidence suggests the involvement of C-Abelson (c-Abl) tyrosine kinase enzyme in the pathology of PD. C-abl plays a role in PD pathology on the levels of parkin activation, alpha synuclein aggregation, and impaired autophagy of toxic elements. Experimental studies showed that (1) c-abl activation is involved in neuronal death and (2) c-abl inhibition shows neuroprotective effects and prevents dopaminergic neurons’ death. Current evidence from experimental studies and the first in-human trial shows that c-abl inhibition holds the promise for neuroprotection against PD and therefore, justifies the movement towards larger clinical trials. In this review article, we discussed the role of c-abl in PD pathology and the findings of preclinical experiments and the first in-human trial. In addition, based on the lessons of the last decade and current preclinical evidence, we provide recommendations for future research in this area

    Experimental study of the impact of dust on azimuth tracking solar PV in Sharjah

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    Dust is one of the significant constraints in utilizing solar photovoltaic systems under harsh weather conditions in the desert regions due to creating a shadow that blocks solar irradiance from reaching solar cells and consequently, significantly reducing their efficiency. In this research, experimental study was performed to comprehend the nature of dust particles and their impact on the electrical power output that is generated from azimuth tracking solar PV modules under Sharjah environmental conditions in winter season. According to laboratory experiments, the power losses are linearly related to the dust accumulated density on the surface of the solar panel with a slope of 1.27% per g/m2. The conducted Outdoor studies revealed that the absolute reduction in output power increased by 8.46% after 41 continuous days with one low-intensity rainy day. The linear relationship obtained from indoor experiments was applied later to estimate the dust deposited density on the outdoor setup. The results showed that a regular cleaning process every two weeks is recommended to maintain the performance and to avoid the soiling loss. This work will help engineers in the solar PV plants to forecast the dust impact and figure out the regularity of the cleaning process in case of single axis tracking systems

    Hepatitis C Virus (HCV) Vertical Transmission in 12-Month-Old Infants Born to HCV-Infected Women and Assessment of Maternal Risk Factors

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    Background. Hepatitis C virus (HCV) is an underappreciated cause of pediatric liver disease, most frequently acquired by vertical transmission (VT). Current guidelines that include the option of screening infants for HCV RNA at 1–2 months are based on data prior to current real-time polymerase chain reaction (PCR)-based testing. Previous studies have demonstrated VT rates of 4%–15% and an association with high maternal viral load. We evaluated HCV RNA in infants with HCV VT and assessed maternal risk factors in a prospective cohort in Cairo, Egypt
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