34 research outputs found
A Versatile Technique for the Fabrication of PEDOT: PSS Films for Organic Solar Cells
Organic solar cells hold the potential of low-cost production as compared to inorganic solar cells, as well as the increase in efficiency. To realize these possibilities, the key is to fabricate most of the functional films in requisite structures via ambient solution-processed techniques. The PEDOT: PSS films, which are commonly used as an anode layer in organic electronic devices, were deposited on large-area ITO glass substrates under optimized conditions. The spin, spray, brush and brush+spray-coating techniques were utilized to examine their suitability in the fabrication of organic solar cells (OSCs). The films were characterized for their morphology, molecular structure, optical and electrical properties and results are compared with the existing data. A smooth and thin films of PEDOT: PSS were obtained by “Spray+Brush” coating method with attractive sheet-conductivity having potential in fabricating OSCs with different architectures.Key words: Organic solar cells; PEDOT: PSS films; Solution-processed technique
Pyroelectric Materials for Uncooled Infrared Detectors: Processing, Properties, and Applications
Uncooled pyroelectric detectors find applications in diverse and wide areas such as industrial production; automotive; aerospace applications for satellite-borne ozone sensors assembled with an infrared spectrometer; health care; space exploration; imaging systems for ships, cars, and aircraft; and military and security surveillance systems. These detectors are the prime candidates for NASA s thermal infrared detector requirements. In this Technical Memorandum, the physical phenomena underlying the operation and advantages of pyroelectric infrared detectors is introduced. A list and applications of important ferroelectrics is given, which is a subclass of pyroelectrics. The basic concepts of processing of important pyroelectrics in various forms are described: single crystal growth, ceramic processing, polymer-composites preparation, and thin- and thick-film fabrications. The present status of materials and their characteristics and detectors figures-of-merit are presented in detail. In the end, the unique techniques demonstrated for improving/enhancing the performance of pyroelectric detectors are illustrated. Emphasis is placed on recent advances and emerging technologies such as thin-film array devices and novel single crystal sensors
Effectiveness of a scalable group-based education and monitoring program, delivered by health workers, to improve control of hypertension in rural India: A cluster randomised controlled trial
New methods are required to manage hypertension in resource-poor settings. We hypothesised that a community health worker (CHW)-led group-based education and monitoring intervention would improve control of blood pressure (BP). We conducted a baseline community-based survey followed by a cluster randomised controlled trial of people with hypertension in 3 rural regions of South India, each at differing stages of epidemiological transition. Participants with hypertension, defined as BP ≥ 140/90 mm Hg or taking antihypertensive medication, were advised to visit a doctor. In each region, villages were randomly assigned to intervention or usual care (UC) in a 1:2 ratio. In intervention clusters, trained CHWs delivered a group-based intervention to people with hypertension. The program, conducted fortnightly for 3 months, included monitoring of BP, education about hypertension, and support for healthy lifestyle change. Outcomes were assessed approximately 2 months after completion of the intervention. The primary outcome was control of BP (BP < 140/90 mm Hg), analysed using mixed effects regression, clustered by village within region and adjusted for baseline control of hypertension (using intention-to-treat principles). Of 2,382 potentially eligible people, 637 from 5 intervention clusters and 1,097 from 10 UC clusters were recruited between November 2015 and April 2016, with follow-up occurring in 459 in the intervention group and 1,012 in UC. Mean age was 56.9 years (SD 13.7). Baseline BP was similar between groups. Control of BP improved from baseline to follow-up more in the intervention group (from 227 [49.5%] to 320 [69.7%] individuals) than in the UC group (from 528 [52.2%] to 624 [61.7%] individuals) (odds ratio [OR] 1.6, 95% CI 1.2-2.1; P = 0.001). In secondary outcome analyses, there was a greater decline in systolic BP in the intervention than UC group (-5.0 mm Hg, 95% CI -7.1 to -3.0; P < 0.001) and a greater decline in diastolic BP (-2.1 mm Hg, 95% CI -3.6 to -0.6; P < 0.006), but no detectable difference in the use of BP-lowering medications between groups (OR 1.2, 95% CI 0.8-1.9; P = 0.34). Similar results were found when using imputation analyses that included those lost to follow-up. Limitations include a relatively short follow-up period and use of outcome assessors who were not blinded to the group allocation. While the durability of the effect is uncertain, this trial provides evidence that a low-cost program using CHWs to deliver an education and monitoring intervention is effective in controlling BP and is potentially scalable in resource-poor settings globally. The trial was registered with the Clinical Trials Registry-India (CTRI/2016/02/006678)
Trends of public health research output from India during 2001-2008
BACKGROUND: An understanding of how public health research output from India is changing in relation to the disease burden and public health priorities is required in order to inform relevant research development. We therefore studied the trends in the public health research output from India during 2001-2008 that was readily available in the public domain. METHODS: The scope and type of the published research from India in 2007 that was included in the PubMed database was assessed and compared with a previous similar assessment for 2002. Papers were classified based on the review of abstracts and original public health research papers were assessed in detail. Impact factors for the journals were used to compute quality-adjusted research output. The websites of governmental organizations, academic and research institutions and international organizations were searched in order to identify and review reports on original public health research produced in India from 2001 to 2008. The reports were classified based on the topics covered and quality and their trends over time were assessed. RESULTS: The number of original health research papers from India in PubMed doubled from 4494 in 2002 to 9066 in 2007. This included a 3.1-fold increase in public health research papers, but these comprised only 5% of the total papers in 2007. Within public health, the increase was lowest for the health system and policy category. Several major causes of disease burden in India continued to be underrepresented in the quality-adjusted public health research output in 2007. The number of papers evaluating population health interventions increased from 2002 to 2007, but there were none on the leading non-communicable causes of disease burden or on road traffic injuries. The number of identified original public health research reports increased by 64.7% from 204 in 2001-2004 to 336 in 2005-2008. The proportion of reports on reproductive and child health was very high but decreased slightly from 38.7% of the total in 2001-2004 to 31.5% in 2005-2008 (P = 0.09); those on the leading chronic non-communicable conditions and injuries increased from 6.4% to 13.4% (P = 0.01) but this was still much lower than their contribution to the disease burden. Health system/policy issues were the topic in 27.4% reports but health information issues were covered in a miniscule 0.6% reports. The proportion of reports that were evaluations increased slightly from 26% in 2001-2004 to 31.5% in 2005-2008, with this proportion being higher among the reports commissioned by international organizations (P < 0.001). The proportion of reports commissioned by Indian governmental organizations alone, or in collaboration with international organizations, doubled from 2001-2004 to 2005-2008 (P < 0.001). Only 25% of the total 540 reports had a quality score of adequate or better. The quality of reports produced by collaborations between Indian and international organizations was higher than those produced by Indian or international organizations alone (P < 0.001). CONCLUSION: This is the first analysis from India that includes research reports in addition to published papers. It provides the most up-to-date understanding of public health research output from India. The increase in available public health research output and the increase in commissioning of this research by Indian governmental organizations are encouraging. However, the distribution of research topics and the quality of research reports continue to be unsatisfactory. It is necessary for health policy to address these continuing deficits in public health research in order to reduce the very large disease burden in India.13 page(s
Process evaluation in the field: global learnings from seven implementation research hypertension projects in low-and middle-income countries
Background
Process evaluation is increasingly recognized as an important component of effective implementation research and yet, there has been surprisingly little work to understand what constitutes best practice. Researchers use different methodologies describing causal pathways and understanding barriers and facilitators to implementation of interventions in diverse contexts and settings. We report on challenges and lessons learned from undertaking process evaluation of seven hypertension intervention trials funded through the Global Alliance of Chronic Diseases (GACD).
Methods
Preliminary data collected from the GACD hypertension teams in 2015 were used to inform a template for data collection. Case study themes included: (1) description of the intervention, (2) objectives of the process evaluation, (3) methods including theoretical basis, (4) main findings of the study and the process evaluation, (5) implications for the project, policy and research practice and (6) lessons for future process evaluations. The information was summarized and reported descriptively and narratively and key lessons were identified.
Results
The case studies were from low- and middle-income countries and Indigenous communities in Canada. They were implementation research projects with intervention arm. Six theoretical approaches were used but most comprised of mixed-methods approaches. Each of the process evaluations generated findings on whether interventions were implemented with fidelity, the extent of capacity building, contextual factors and the extent to which relationships between researchers and community impacted on intervention implementation. The most important learning was that although process evaluation is time consuming, it enhances understanding of factors affecting implementation of complex interventions. The research highlighted the need to initiate process evaluations early on in the project, to help guide design of the intervention; and the importance of effective communication between researchers responsible for trial implementation, process evaluation and outcome evaluation.
Conclusion
This research demonstrates the important role of process evaluation in understanding implementation process of complex interventions. This can help to highlight a broad range of system requirements such as new policies and capacity building to support implementation. Process evaluation is crucial in understanding contextual factors that may impact intervention implementation which is important in considering whether or not the intervention can be translated to other contexts
Large pyroelectric properties at reduced depolarization temperature in A-site nonstoichiometry composition of lead-free 0.94Na x Bi y TiO3–0.06Ba z TiO3 ceramics
The compliance of packaged food products in India with national and international nutritional labelling standards
Efficient Planar Perovskite Solar Cell by Spray and Brush Solution-Processing Methods.
Perovskite compounds have the potential to transform photovoltaics technology, as they are easy to fabricate, have better stability, and possess superior power conversion efficiency. In this research, a versatile solution-processing method called spray+brush (SB) has been adopted to achieve a power-conversion efficiency of 3.52% for pure organometal halide perovskite devices. It has been observed that this method is more efficient and cost effective than the perovskite devices fabricated by spray (1.95%) and brush (1.17%) methods alone. The SB method of solution processing can be promising for various other organic coatings
Pyroelectric Ceramics for Infrared Detection Applications
Pyroelectric and dielectric properties of modified PZT and PZ have been studied for their use in infrared detectors. Various material figure-of-merits for their use in infrared detector are calculated including when the pyroelectric element is placed on heat-sink condition. The results are compared with exiting candidate materials