275 research outputs found

    Performance Enhancement of a Variable Speed Permanent Magnet Synchronous Generator Used for Renewable Energy Application

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    The paper aims to develop an improved control system to enhance the dynamics of a permanent magnet synchronous generator (PMSG) operating at varying speeds. The generator dynamics are evaluated based on lowing current, power, and torque ripples to validate the effectiveness of the proposed control system. The adopted controllers include the model predictive power control (MPPC), model predictive torque control (MPTC), and the designed predictive voltage control (PVC). MPPC seeks to regulate the active and reactive power, while MPTC regulates the torque and flux. MPPC and MPTC have several drawbacks, like high ripple, high load commutation, and using a weighting factor in their cost functions. The methodology of designed predictive voltage comes to eliminate these drawbacks by managing the direct voltage by utilizing the deadbeat and finite control set FCS principle, which uses a simple cost function without needing any weighting factor for equilibrium error issues. The results demonstrate several advantages of the proposed PVC technique, including faster dynamic response, simplified control structure, reduced ripples, lower current harmonics, and decreased computational requirements when compared to the MPPC and MPTC methods. Additionally, the study considers the integration of blade pitch angle and maximum power point tracking (MPPT) controls, which limit wind energy utilization when the generator speed exceeds its rated speed and maximize wind energy extraction during wind scarcity. In summary, the proposed PVC enhanced control system exhibits superior performance in terms of dynamic response, control simplicity, current quality, and computational efficiency when compared to alternative methods

    The influence of green modification of lignin on the electrochemical properties of biocomposites for industrial applications

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    It’s a report on a novel approach; preparation and electrochemical properties of modified lignin. Wax and starch were used as natural, green adhesives for enhancing the electrical resistivity of lignin in acidic medium, forming eco-friendly high insulator biocomposite. Scanning electron microscopy (SEM) was used to characterize the fabricated biocomposite. The modified lignin was characterized using Fourier transform infrared (FTIR), while the electrochemical behavior was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The innovative approach described in this work provides a promising eco- friendly method for lignin modification with highly electrical resistivity and stability with time.Â

    Protective Effect of Parsley Juice ( Petroselinum crispum

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    Parsley was used as a probe of the current experiment to prevent the behavioral, morphological and biochemical changes in the newborn brain following the administration of cadmium (Cd) to the pregnant mice. The nonanesthetized pregnant mice were given daily parsley juice (Petroselinum crispum) at doses of 20 mg/kg and 10 mg/kg. Pregnant mothers were given Cd at a dose of 30 mg/kg divided into 3 equal times. The newborns have been divided into 6 groups: Group A, mothers did not take treatment; Groups B and C, mothers were treated with low and high dose of parsley, respectively; Group D, mothers were treated only with Cd (perinatal intoxication); Groups E and F, mothers were treated with Cd doses and protected by low and high doses of parsley, respectively. Light microscopy showed that Cd-induced neuronal degeneration by chromatolysis and pyknosis in the brain regions. The low dose of parsley 10 g/kg/day exhibited significant effects in neutralizing and reducing the deleterious changes due to Cd exposure during pregnancy on the behavioral activities, neurotransmitters, oxidative stress, and brain neurons morphology of the mice newborns

    Promising anti-microbial effect of apple vinegar as a natural decolonizing agent in healthcare workers

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    Introduction: Colonized Healthcare workers (HCWs) are an essential reservoir of nosocomial infections. This study aims to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage rate among HCWs, to evaluate at Fayoum University Hospital the susceptibility of isolates to mupirocin and Chlorhexidine and to investigate the antimicrobial effect of different vinegars on MRSA as a natural decolonizing agent. Methods: Nasal and hand swabs were collected from 124 HCWs at Fayoum University Surgical Hospital. Isolates were identified using the standard microbiological methods. Susceptibilities to mupirocin and Chlorhexidine were determined by disk diffusion and broth micro-dilution. Screening antimicrobial effect of commercial vinegars was determined by agar well-diffusion method and microdilution method. Results: About one tenth 11.3% (14/124) of HCWs showed nasal carriage of MRSA. Workers were the predominant carriers (P = 0.013). The overall non-nasal carriage rate of MRSA was 6.5% (8/124). Among MRSA isolates Low-level Mupirocin resistance (LLMR) showed in (36.4%, 8/22). MICs ranged from 0.25 to 32 μg/ml. Also, (13.6 %, 3/22) showed Chlorhexidine resistance, MICs ranged from 0.039 to 5 μg/ml. Apple vinegar showed the highest susceptibility among vinegars (p < 0.0001) with MIC values varied from 0.058 to 1.87 μg/ml Discussion: The emergence of mupirocin (36.4%) and Chlorhexidine (13.6%) resistant Staphylococcus aureus among HCWs should be of excessive concern. Apple vinegar has a promising antimicrobial effect against MRSA isolates and could be used as a decolonizing agent

    Structured Health Literacy Intervention for Mothers Regarding Stem Cells Therapy

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    Background: Stem cells have tremendous promise uses for the future to treat a variety of diseases, injuries, and other health-related conditions. Their potential is evident to promote the repair response of diseased, dysfunctional or injured tissue. Aim: This study aimed to assess the effectiveness of applying a structured health literacy intervention regarding stem cells therapy (SCT) on the mothers' level of knowledge and attitude. Methodology: A quasi-experimental one-group pre-post test design was utilized. The study involved 302 mothers recruited from the pediatric outpatient clinics of Mansoura University Children Hospital (MUCH), Egypt. Data were collected using two structured interview sheets (knowledge and attitude). Results: There were highly statistically significant differences in mothers’ knowledge and attitude one-month post-application of the structured health literacy intervention regarding stem cells therapy compared to pre-application (P=<0.001). Conclusion: Application of a structured health literacy intervention showed a significant improvement in mothers' level of knowledge and attitude regarding stem cells therapy. Keywords: Attitude, Health Literacy, Knowledge, Stem Cells Therapy. DOI: 10.7176/JHMN/61-06 Publication date: April 30th 201

    Hepatitis B virus and hepatitis C virus in pregnant Sudanese women

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    <p>Abstract</p> <p>Background</p> <p>The epidemiology of viral hepatitis during pregnancy is essential for health planners and programme managers. While much data exist concerning viral hepatitis during pregnancy in many African countries, no proper published data are available in Sudan.</p> <p>Aim</p> <p>The study aimed to investigate the sero-prevalance and the possible risk factors for hepatitis B virus (HBV) and hepatitis C virus (HCV) among antenatal care attendants in central Sudan.</p> <p>Methods</p> <p>During 3 months from March–June 2006, sera were collected from pregnant women at Umdurman Maternity Hospital in Sudan, and they were tested for markers of hepatitis B virus (HBVsAg) and HCV.</p> <p>Results</p> <p>HBVsAg was detected in 41 (5.6%) out 728 women, Anti-HCV was detected in 3 (0.6%) out of 423 women, all of them were not aware of their condition. Age, parity, gestational age, residence, history of blood transfusion, dental manipulations, tattooing and circumcision did not contribute significantly to increased HBVsAg sero-positivity.</p> <p>Conclusion</p> <p>Thus 5.6% of pregnant women were positive for HBVsAg irrespective of their age, parity and socio-demographic characteristics. There was low prevalence of Anti-HCV.</p

    Quality of care of Egyptian asthmatic children: Clinicians adherence to asthma guidelines

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    <p>Abstract</p> <p>Background</p> <p>Despite the development and dissemination of guidelines for the diagnosis and management of asthma, a gap remains between current recommendations and actual practice.</p> <p>Objectives</p> <p>To assess the physicians attitude towards asthma guidelines and their adherence to its recommendations.</p> <p>Methods</p> <p>Three hundred and fifty two clinicians (101 General practitioners, 131 pediatric specialists, 35 pediatric consultants and 85 doctors did not report the qualification) engaged in direct childhood asthma care in Cairo, Egypt were subjected to a self-administered questionnaire with 35 questions of which most were multiple choices, aiming at assessment of three important aspects about the involved physicians; physician's knowledge, practice and attitude. 165 of the clinicians were working in governmental hospitals, 68 clinicians work in private clinics and 119 clinicians work in both.</p> <p>Results</p> <p>Agreement with asthma guidelines was present in 76.2% of the studied physicians, however those who not in agreement with the guidelines claimed that this was mainly due to patient factors, firstly the poor socioeconomic standard of the patient (18.1%) and secondly due to poor patient compliance (16%). Poor knowledge was found in 28.5%, poor practice was found in 43.6% and poor attitude was found in 14.4% of the studied physicians. There was positive highly significant correlation between qualification and knowledge, (p < 0.01), positive highly significant correlation between qualification and practice, (p < 0.01), and positive highly significant correlation between qualification and attitude, (p < 0.01).</p> <p>Conclusion</p> <p>The attitude of the studied physicians revealed agreement of their majority with the guidelines, while the disagreement was mainly explained by the poor socioeconomic standard of the patients. The degree of poor practice is more marked than that of poor knowledge or poor attitude reflecting resources limitations and applications obstacles in the physician's practice.</p

    Twenty Years of Mobile Banking Services Development and Sustainability: A Bibliometric Analysis Overview (2000–2020)

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    The current paper aims to analyze the keywords related to mobile banking (otherwise known as m-banking) issues by focusing on its development from 2000 to 2020, of which the first publication about this issue appeared in the Scopus database. This paper explored and analyzed 1206 research papers using the Scopus database. Bibliometric analysis and content analysis had been conducted through Excel and VOS viewer software to obtain the results. In addition, the findings of this paper reveal that the universal trends and increased production at a global level led to many changes, and the most rampant topic associated with m-banking in most periods is mobile telecommunication systems. By showcasing the creation of the key terms in m-banking, it was possible to identify significant changes in the development of the field\u27s key terminologies. Therefore, it is important to follow up on the development in future decades, particularly how the recent universal occurrences have influenced the changes in m-banking use at a global level. Moreover, the present study makes a significant contribution to the literature by providing a framework for future research. The framework provides opportunities for researchers to explore the research streams in future research. Finally, the current paper is the first of its kind in its method of contribution, ad according to the research databases (Scopus, Google Scholar, etc.), no work was witnessed in the published literature covering m-banking in a detailed and comprehensive multi-period manner and in such an applied method. In addition, the current paper fills this gap by conducting a bibliometric analysis and content analysis

    A practical guide to managing hypertension, hyperlipidemia, and hyperglycemia in patients with chronic myeloid leukemia

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    Tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of chronic myeloid leukemia (CML) since their approval. Although safe in general, TKIs carry concerns about cardiovascular adverse events. Hypertension, diabetes, and dyslipidemia are among the most common baseline comorbidities among CML patients. Guidelines for the management of the existing comorbidities or those related to TKI therapy are lacking. This paper will review hypertension, hyperglycemia and hyperlipidemia reported in CML patients or associated with TKI therapy and then propose a simple guide on their management

    Major depression and disease activity among systemic lupus erythematosus Egyptian females

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    AbstractAim of the workThe aim of this study was to identify the relationship between disease activity in SLE Egyptian females and the presence, severity and pattern of major depression in these patients.Patients and methodsThe study sample included 100 female patients; fifty SLE patients and fifty healthy adults with matching age serving as control. Patients were assessed using Beck Inventory Score for the presence of major depression, SLEDAI to determine disease activity, SLICC/ACR damage index and HAQ score for functional disability.ResultsThe majority of patients had symptoms of major depression 32/50 (64%) based on Beck Inventory Score while in controls only 16/50 (36%) had major depression. The most common depressive symptoms in SLE patients were: Guilty feeling (92%), Self-dislike (91.6%), Self-criticalness (90.4%), Crying spells (87.5%), Loss of pleasure (83.3%), Change in appetite (83.3%), Agitation (82.8%) and Pessimism (82%). Patients with major depression presented a trend toward having greater severity of SLE disease activity compared with those without major depression (p=0.04). The presence of major depression was significantly associated with functional disability measured by HAQ score (p=0.01). The patients with major depression did not differ significantly from patients without major depression regarding their steroid dosage (p=0.55), SLICC/ACR damage score (p=0.16) and disease duration (p=0.69) but differed significantly as regards Beck Hopelessness Scale (p<0.0001) and suicidal ideation score (p=0.009).ConclusionMajor depression was highly presented in Egyptian SLE patients (64%); its severity was associated with disease activity, but not with steroid administration, cumulative damage or disease duration
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