40 research outputs found

    Investigation on the Performance of UPQC-Q for Voltage Sag Mitigation and PQ Improvement at a Critical Load Point

    Get PDF
    The unified power quality conditioner (UPQC) is one of the major custom power solutions, which is capable of mitigating the effect of supply voltage sag at the load end or at the point of common coupling (PCC) in a distributed network. It also prevents the propagation of the load current harmonics to the utility and improves the input power factor of the load. The control of series compensator (SERC) of the UPQC is such that it injects voltage in quadrature advance to the supply current. Thus, the SERC consumes no active power at steady state. The other advantage of the proposed control scheme is that the SERC can share the lagging VAR demand of the load with the shunt compensator (SHUC) and can ease its loading. The UPQC employing this type of quadrature voltage injection in series is termed as UPQC-Q. The VA requirement issues of SERC and SHUCs of a UPQC-Q are discussed. A PC-based new hybrid control has been proposed and the performance of the UPQC-Q is verified in a laboratory prototype. The phasor diagram, control block diagram, simulations and experimental results are presented to confirm the validity of the theory

    Experimental investigation of performance of a single phase UPQC for voltage sensitive and non-linear loads

    Get PDF
    A unified power quality conditioner (UPQC) is proposed in this paper. It protects the consumer at the load end from supply voltage sag, and provides unity power factor condition at the utility for different values of load power factor. A PC-based closed loop control scheme is proposed and experimental investigation is carried out in the laboratory. Selected experimental results are reported along with control circuit and phasor diagram to validate the proposition

    Repressor of temperate mycobacteriophage L1 harbors a stable C-terminal domain and binds to different asymmetric operator DNAs with variable affinity

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Lysogenic mode of life cycle of a temperate bacteriophage is generally maintained by a protein called 'repressor'. Repressor proteins of temperate lambdoid phages bind to a few symmetric operator DNAs in order to regulate their gene expression. In contrast, repressor molecules of temperate mycobacteriophages and some other phages bind to multiple asymmetric operator DNAs. Very little is known at present about the structure-function relationship of any mycobacteriophage repressor.</p> <p>Results</p> <p>Using highly purified repressor (CI) of temperate mycobacteriophage L1, we have demonstrated here that L1 CI harbors an N-terminal domain (NTD) and a C-terminal domain (CTD) which are separated by a small hinge region. Interestingly, CTD is more compact than NTD at 25°C. Both CTD and CI contain significant amount of α-helix at 30°C but unfold partly at 42°C. At nearly 200 nM concentration, both proteins form appreciable amount of dimers in solution. Additional studies reveal that CI binds to <it>O</it><sub>64 </sub>and <it>O</it><sub><it>L </it></sub>types of asymmetric operators of L1 with variable affinity at 25°C. Interestingly, repressor – operator interaction is affected drastically at 42°C. The conformational change of CI is most possibly responsible for its reduced operator binding affinity at 42°C.</p> <p>Conclusion</p> <p>Repressors encoded by mycobacteriophages differ significantly from the repressor proteins of λ and related phages at functional level but at structural level they are nearly similar.</p

    Eye diseases: the neglected health condition among urban slum population of Dhaka, Bangladesh

    Get PDF
    Introduction: Globally, eye diseases are considered as one of the major contributors of nonfatal disabling conditions. In Bangladesh, 1.5% of adults are blind and 21.6% have low vision. Therefore, this paper aimed to identify the community-based prevalence and associated risk factors of eye diseases among slum dwellers of Dhaka city. Methods: The study was carried out in two phases. In the first phase, a survey was conducted using multistage cluster sampling among 1320 households of three purposively selected slums in Dhaka city. From each household, one family member (≥ 18 years old) was randomly interviewed by trained data collectors using a structured questionnaire. After that, each of the participants was requested to take part in the second phase of the study. Following the request, 432 participants out of 1320 participants came into the tertiary care hospitals where they were clinically assessed by ophthalmologist for presence of eye diseases. A number of descriptive and inferential statistics were performed using Stata 13. Result: The majority of total 432 study participants were female (68.6%), married (82.6%) and Muslim (98.8%). Among them almost all (92.8%) were clinically diagnosed with eye disease. The most prevalent eye diseases were refractive error (63.2%), conjunctivitis (17.1%), visual impairment (16.4%) and cataract (7.2%). Refractive error was found significantly associated with older age, female gender and income generating work. Cataract was found negatively associated with the level of education, however, opposite relationship was found between cataract and visual impairment. Conclusion: Our study provides epidemiologic data on the prevalence of eye diseases among adult population in low-income urban community of Dhaka city. The high prevalence of refractive error, allergic conjunctivitis, visual impairment, and cataract among this group of people suggests the importance of increasing access to eye care services

    Perceptions of quality across the maternal care continuum in the context of a health financing intervention: Evidence from a mixed methods study in rural Malawi

    Get PDF
    Background: In 2013, Malawi with its development partners introduced a Results-Based Financing for Maternal and Newborn Health (RBF4MNH) intervention to improve the quality of maternal and newborn health-care services. Financial incentives are awarded to health facilities conditional on their performance and to women for delivering in the health facility. We assessed the effect of the RBF4MNH on quality of care from women’s perspectives. Methods: We used a mixed-method prospective sequential controlled pre- and post-test design. We conducted 3060 structured client exit interviews, 36 in-depth interviews and 29 focus group discussions (FGDs) with women and 24 in-depth interviews with health service providers between 2013 and 2015. We used difference-in-differences regression models to measure the effect of the RBF4MNH on experiences and perceived quality of care. We used qualitative data to explore the matter more in depth. Results: We did not observe a statistically significant effect of the intervention on women’s perceptions of technical care, quality of amenities and interpersonal relations. However, in the qualitative interviews, most women reported improved health service provision as a result of the intervention. RBF4MNH increased the proportion of women reporting to have received medications/treatment during childbirth. Participants in interviews expressed that drugs, equipment and supplies were readily available due to the RBF4MNH. However, women also reported instances of neglect, disrespect and verbal abuse during the process of care. Providers attributed these negative instances to an increased workload resulting from an increased number of women seeking services at RBF4MNH facilities. Conclusion: Our qualitative findings suggest improvements in the availability of drugs and supplies due to RBF4MNH. Despite the intervention, challenges in the provision of quality care persisted, especially with regard to interpersonal relations. RBF interventions may need to consider including indicators that specifically target the provision of respectful maternity care as a means to foster providers’ positive attitudes towards women in labour. In parallel, governments should consider enhancing staff and infrastructural capacity before implementing RBF

    Research priorities in Maternal, Newborn, &amp; Child Health &amp; Nutrition for India:An Indian Council of Medical Research-INCLEN Initiative

    Get PDF
    In India, research prioritization in Maternal, Newborn, and Child Health and Nutrition (MNCHN) themes has traditionally involved only a handful of experts mostly from major cities. The Indian Council of Medical Research (ICMR)-INCLEN collaboration undertook a nationwide exercise engaging faculty from 256 institutions to identify top research priorities in the MNCHN themes for 2016-2025. The Child Health and Nutrition Research Initiative method of priority setting was adapted. The context of the exercise was defined by a National Steering Group (NSG) and guided by four Thematic Research Subcommittees. Research ideas were pooled from 498 experts located in different parts of India, iteratively consolidated into research options, scored by 893 experts against five pre-defined criteria (answerability, relevance, equity, investment and innovation) and weighed by a larger reference group. Ranked lists of priorities were generated for each of the four themes at national and three subnational (regional) levels [Empowered Action Group & North-Eastern States, Southern and Western States, & Northern States (including West Bengal)]. Research priorities differed between regions and from overall national priorities. Delivery domain of research which included implementation research constituted about 70 per cent of the top ten research options under all four themes. The results were endorsed in the NSG meeting. There was unanimity that the research priorities should be considered by different governmental and non-governmental agencies for investment with prioritization on implementation research and issues cutting across themes

    Prevalence of chronic kidney disease in South Asia: a systematic review

    Get PDF
    Background: Chronic kidney disease (CKD) is becoming a major public health problem around the world. But the prevalence has not been reported in South Asian region as a whole. This study aimed to systematically review the existing data from population based studies in this region to bridge this gap. Methods Articles published and reported prevalence of CKD according to K/DOQI practice guideline in eight South Asian countries between December 1955 and April 2017 were searched, screened and evaluated from seven electronic databases using the PRISMA checklist. CKD was defined as creatinine clearance (CrCl) or GFR less than 60 ml/min/1.73 m2. Results Sixteen population-based studies were found from four South Asian countries (India, Bangladesh, Pakistan and Nepal) that used eGFR to measure CKD. No study was available from Sri Lanka, Maldives, Bhutan and Afghanistan. Number of participants ranged from 301 in Pakistan to 12,271 in India. Majority of the studies focused solely on urban population. Different studies used different equations for measuring eGFR. The prevalence of CKD ranged from 10.6% in Nepal to 23.3% in Pakistan using MDRD equation. This prevalence was higher among older age group people. Equal number of studies reported high prevalence among male and female each. Conclusions This systematic review reported high prevalence of CKD in South Asian countries. The findings of this study will help pertinent stakeholders to prepare suitable policy and effective public health intervention in order to reduce the burden of this deadly disease in the most densely populated share of the globe

    A critical exploration of forces impacting mental health and psychosocial wellbeing of conflict-induced displaced persons in Hong Kong

    No full text
    Refugees, asylum seekers, and survivors of torture and cruel, inhuman, degrading treatment or punishment (persons of concern (PoC)) in Hong Kong are extremely resilient people. Many however, are challenged with conflict displacement traumas that often go unaddressed. To compound matters, they have little livelihood options and live in an uncertain state while their protection claims are slowly processed; there is little chance of success. On a daily basis, their bio-psycho-social-spiritual wellbeing intertwines with and is impacted by services and policy within the ecological system in Hong Kong. This doctoral dissertation study uses an ecological systems framework, critical paradigm and social justice perspective to explore how PoC mental health and psychosocial (MHPS) wellbeing are interconnected to systemic and environmental forces. Three phases of narrative inquiry with PoC participants and service providers illuminate PoC lived experiences and provider insight and suggestions at the micro, mezzo and macrosystem of the ecological environment. Inductive and deductive interpretive thematic analysis generates theoretical contributions. The deterioration of mental and overall health were linked to oppressive policy and services such as protection screening retraumatization, inadequate healthcare and inability to work. Traumatic uncertainty negatively affected their lives and was primary linked to their overall deterioration. All systems presented different levels of boundary openness and permeability across ecological interactions. Ultimately, there was systemic empathic failure within the sub-systems of the ecological environment. An array of physical, mental and behavioral health issues have manifested for PoC and often become prolonged due to several systemic barriers. While there is empathic failure in some of the sub-systems, there is also systemic empathic attunement in other areas. Human interaction through empathy could enable more openness in the whole system. Empathic growth pathways to multi-level, trauma-informed services and care are provided and based on the research findings and global MHPSS recommendations. Empathic growth can transform empathic failure into empathic attunement. As the ecological system in Hong Kong enhances its empathy for PoC, positive holistic health and wellbeing for PoC can be realized. While being confronted with extreme levels of gross human rights violations and severe social injustice created by oppressive systems and structures, social work is in a prime position to advocate for change and for the betterment of this resilient yet vulnerable community. Awareness of the ecological connection is essential in work with conflict-induced forced migrants. Also, using an integrated approach can be useful in therapeutic work. Overall strengths based services informed by community, tailored to the context, using advocacy lens can be essential for community empowerment and holistic and trauma-informed health promotion. There is a valuable place for the social work profession to be at the forefront of advocacy, multi-level services, healing and therapy, and research and education within this rapidly evolving practice area.published_or_final_versionSocial Work and Social AdministrationDoctoralDoctor of Philosoph
    corecore