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We reported cases of Graves’ ophthalmopathy who presented solely with symptoms of the eyes and normal thyroid function tests, negative TSH receptor autoantibody (TRAb). These cases were referred to our hospital for unilateral or bilateral eye swelling with painful eye movements, with or without double vision, without any signs or symptoms of hyper- or hypothyroidism. Serum thyroid function tests and 99mTc uptake studies were within the normal range. Anti-thyroid autoantibodies (TRAb) were negative in all the cases. Since orbital CT scan and MRI gave typical results compatible with Graves’ ophthalmopathy and after exclusion of other possibilities, these patients were treated with corticosteroid pulse therapy and orbital radiation therapy, leading to a partial improvement of the symptoms. We followed up those cases with serial thyroid profile testing and TRAb estimation and they were subsequently developed clinical & biochemical hyperthyroidism within the next 18 months follow-up. At that time, they also became TRAb positive. These cases give us insight into the potential pathophysiologic mechanism underlying Graves’ ophthalmopathy and cast light upon the difficulties of establishing the diagnosis in biochemically euthyroid & thyroid autoantibody negative cases. Clinicians should be aware of the variable temporal relationship between the clinical expression of thyroid dysfunction and orbital disease in the natural course of Graves’ disease.

IntroductionThe delay in seeking emergency obstetric care leads to significant maternal morbidity and mortality and can worsen during pandemics, especially in humanitarian conflict settings with low uptake of obstetric services. To mitigate the challenges related to the second delay caused by lack of transport in the COVID-19 pandemic, the organisation United Nations Population Fund implements a community-based referral project called Referral Hub in the Rohingya refugee population in Bangladesh. The objective of the paper is to describe the implementation process of the Referral hub and present clients’ utilisation and perception of the service.MethodsFindings from part of a larger mixed-method study, the analysis of the standard operating protocol of the intervention, secondary data of routine utilisation of the 12 referral hubs between January and August 2020, 21 key informant interviews and a community survey among 100 pregnant women are presented in this paper.ResultsThe findings show an increasing trend in the referral hub utilisation and a strong recommendation of the service.ConclusionDue to a robust referral mechanism by collaborating with the community and engaging accessible and free of cost transport service, the intervention has high potential to improve access to facility care in low-resource and humanitarian contexts, especially during pandemics.

Background: Insulin resistance is a major cause for developing type 2 diabetes but is not synonymous with the type 2 diabetes. Pancreatic beta cell dysfunction probably needs to be sets in for clinical occurrence of type 2 diabetes. So knowledge regarding residual beta cell function and degree of insulin resistance is essential. Aims and Objectives: The objectives are as follows: (1) To estimate degree of insulin resistance (HOMA-IR) and pancreatic beta cell functional capacity (HOMA-B %) among newly detected Type 2 diabetics and (2) to identify different clinical phenotypic presentations of type 2 diabetes on the basis of these parameters. Materials and Methods: This present study was conducted in newly diagnosed type 2 diabeticpatients. After obtaining informed consent, anthropometric and clinical examination was carried out in all patients. Venous blood samples were drawn for fasting plasma glucose,c-peptide,fasting insulin level,HbA1c,lipid profile, etc.HOMA-IR and HOMA-B% were calculated with HOMA 2 calculator. Results: A total 100 newly diagnosed type 2 diabetic patients were studied. About 71% pt of study population had HOMA-B% value below 50% and half of study population had significant amount of insulin resistance. Three distinct clinical phenotypes had identified. Insulin resistance predominant group (30%), beta cell dysfunction predominant group (45%), and both abnormalities coexist group (25%). Conclusion: By the time of diagnosis of Type 2 diabetes, more than two-third study population had

Type 2 diabetes mellitus (T2DM) has a high morbidity and mortality mainly due to cardiovascular diseases. Besides traditional risk factors, Lp(a) has recently been emerged as an independent risk factor. This study aimed to evaluate the incidences of elevated Lp(a) levels in newly diagnosed T2DM Pts and to find the pattern of lipid profile abnormalities associated with elevated Lp(a) group of pts & it’s correlation with glycemic & lipid parameters.This present study was conducted in newly diagnosed treatment naïve type 2 diabetic patients. After obtaining informed consent, all participants completed a survey to obtain anthropometric & clinical information. Venous blood samples were drawn for fasting plasma glucose, postprandial glucose, HbA1c,lipid profile & Lp(a) measurements.A total 70 newly diagnosed type 2 diabetic pts & 50 healthy controls were studied. The mean Lp(a)level measured among diabetics was 34.17 ±33.25 mg/dl. The mean concentration of Lp(a) in diabetics was significantly higher than control group(Our study demonstrated Type 2 diabetics had statistically significant higher levels of Lp(a). The residual lipid risk is probably contributed by this molecule So, every diabetic should have checked their level at least once in a lifetime to predict CV risk.

Building-level electrical distribution systems comprise a myriad of current-carrying equipment, conversion devices, and protection devices that deliver power from the utility or local distributed energy resources to end-use building loads. Electric power has traditionally been generated, transmitted, and distributed in alternating current (AC). However, the last decade has seen a significant increase in the integration of native direct current (DC) equipment that has elevated the importance of DC distribution systems. Numerous studies have comparatively examined the performance of various electrical distribution systems in buildings but have failed to achieve uniform conclusions, primarily because of a lack of consistent and analogous performance evaluation methods. This paper aims to fill this gap by providing a standard set of metrics and measurement boundaries to consistently evaluate the performance of AC, DC, or hybrid AC/DC electrical distribution systems. The efficacy of the proposed approach is evaluated on a representative medium-sized commercial office building model with AC distribution and an equivalent hybrid AC/DC and DC distribution model, wherein the AC distribution model is concluded to be the most efficient. The simulation results show variation in computed metrics with different selected boundaries that verify the effectiveness of the proposed approach in ensuring consistent computation of the performance of building-level electrical distribution systems. This paper provides an initial set of guidelines for building energy system stakeholders to adopt appropriate solutions, thus leading to more efficient energy systems.

In Bangladesh, the peaking power plants that serve the peak time loads use conventional fossil fuels for power generation. These power stations remain idle for a good part of their operating life, which therefore results in a high overhead cost. Continuous integration of renewables into the grid is increasing the dependency on these, so far, feasibility of no other less-expensive options has been studied. In this context, this paper aims to analyze the financial feasibility of different alternative options. Three possible options were analyzed and the levelized cost of energy (LCOE) was compared with that of conventional peaking power plants. It was found that Battery-based storage systems are not financially feasible at this moment, while the nation’s lone hydro power plant promises financial feasibility if solar PV driven pumped hydro storage is implemented. We also report that if the nation continues to add solar PV power stations even with costly peaking power plants using traditional fuels, this hybrid option was counter intuitively found to be financially feasible.

Background Delays in seeking timely maternity care from health care professionals are crucial to address among the Rohingya population where many preventable pregnancy-related deaths occur within the camps when care is not sought. To address the challenges related to the referral of emergency and routine Sexual and Reproductive Health and Rights (SRHR) cases, United Nations Population Fund, through its partners, implemented a community-based referral transportation project called Referral hub. This paper presents the barriers and facilitators to the implementation of this referral transportation system from the perspectives of the beneficiaries and providers. Methods The research adopted a sequential explanatory mixed-method design. The quantitative phase consisted of a survey among 100 women while the qualitative phase comprised of in-depth interviews with a total of 12 mothers who used the services and key informant interviews with 21 providers. Results The barriers identified for referral hub are discordant understanding of emergency, strict gender norms and practices, distrust in providers, poor roads and mobile phone networks. The facilitators are partnership with the community, within and other organizations. Conclusion The study observed that the referral hub has a high potential to increase the utilization of SRHR services. Despite the barriers, the facilitating factors show a scope of improvement for these services.

Background: The number of validated quantification methods for rifampicin, a prototypical Oatp inhibitor, in biological rat samples was limited. Objective: This study was conducted to validate a modified reversed-phase liquid chromatographic method for the determination of rifampicin in rat liver tissue according to the current ICH M10 Bioanalytical Method Validation Draft Guideline (2019) for application to samples of in situ rat liver perfusion studies. Methods: Liver tissue samples were obtained from recirculatory in situ rat liver perfusion studies. The analysis was performed on a C18 column with a mobile phase composed of 0.05 M phosphate buffer (pH 4.58): acetonitrile (55:45, v/v). The assay was validated for selectivity, calibration curve and range, matrix effect, carry-over, accuracy and precision, reinjection reproducibility, and stability. Results: he method was considered selective and stable, without having carry-over and matrix effects. The calibration curve was linear (R2: 0.9983) within the calibration range (0.5-60 ppm). Accuracy and precision values fulfilled the required limits. Liver concentrations of rifampicin in liver tissue, obtained after 60 min perfusion with 10 μM and 50 μM of rifampicin, were 45.1 ± 11.2 and 313.4 ± 84.4 μM, respectively. Conclusion: The bioanalytical method validation was completed and the method was successfully applied for the determination of rifampicin in rat liver tissue.

Background BRAC (Bangladesh Rural Advancement Committee), the largest NGO globally, implemented a community-based comprehensive social behavior communication intervention to increase community resilience through prevention, protection, and care for COVID-19. We conducted implementation research to assess fidelity and explore the barriers and facilitators of this intervention implementation. Methods We adopted a concurrent mixed-method triangulation design. We interviewed 666 members of 60 Community Corona Protection Committees (CCPCs) and 80 members of 60 Community Support Teams (CSTs) through multi-stage cluster sampling using a structured questionnaire. The qualitative components relied on 54 key informant interviews with BRAC implementers and government providers. Results The knowledge about wearing mask, keeping social distance, washing hands and COVID-19 symptoms were high (on average more than 70%) among CCPC and CST members. While 422 (63.4%) CCPC members reported they ‘always’ wear a mask while going out, 69 (86.3%) CST members reported the same practice. Only 247 (37.1%) CCPC members distributed masks, and 229 (34.4%) donated soap to the underprivileged population during the last two weeks preceding the survey. The key facilitators included influential community members in the CCPC, greater acceptability of the front-line health workers, free-of-cost materials, and telemedicine services. The important barriers identified were insufficient training, irregular participation of the CCPC members, favouritism of CCPC members in distributing essential COVID-19 preventive materials, disruption in supply and shortage of the COVID-19 preventative materials, improper use of handwashing station, the non-compliant attitude of the community people, challenges to ensure home quarantine, challenges regarding telemedicine with network interruptions, lack of coordination among stakeholders, the short duration of the project. Conclusions Engaging the community in combination with health services through a Government-NGO partnership is a sustainable strategy for implementing the COVID-19 prevention program. Engaging the community should be promoted as an integral component of any public health intervention for sustainability. Engagement structures should incorporate a systems perspective to facilitate the relationships, ensure the quality of the delivery program, and be mindful of the heterogeneity of different community members concerning capacity building. Finally, reaching out to the underprivileged through community engagement is also an effective mechanism to progress through universal health coverage.

Low cost, multinary colloidal quantum dots (QDs) based on environmentally friendly elements, with bright, narrow-width, tunable near-infrared (NIR) luminescence are promising alternatives to Cd and Pb chalcogenide QDs for in vivo bio-imaging, LED and sensing applications. Herein, we demonstrate Pb/Cd free solution-processed colloidal luminescent Ag2ZnSnS4–ZnS (AZTS–ZnS) core–shell QDs with precise control over the ZnS shell thickness and thereby its optical properties. Unlike indium based multinary (I–III–VI group) core–shell QDs these nanocrystals show a narrow photoluminescence (PL) full width at half maximum (fwhm) of 105–110 meV in the first NIR window. By monitoring the starting AZTS core size, we achieve tunable emission over a small NIR window in these QDs with the best PL quantum yield (PLQY) of 17.4%., Passivation and optimization of luminescent AZTS QDs with ZnS shells gave rise to a ∼30-fold increase in the PLQY results in RoHS compliant low-cost, bright and tunable NIR-luminescent phosphors for bio-imaging and LED applications.

Driven by the proliferation of DC energy sources and DC end-use devices (e.g., photovoltaics, battery storage, solid-state lighting, and consumer electronics), DC power distribution in buildings has recently emerged as a path to improved efficiency, resilience, and cost savings in the transitioning building sector. Despite these important benefits, there are several technological and market barriers impeding the development of DC distribution, which have kept this technology at the demonstration phase. This paper identifies specific end-use cases for which DC distribution in buildings is viable today. We evaluate their technology and market readiness, as well as their efficiency, cost, and resiliency benefits while addressing implementation barriers. The paper starts with a technology review, followed by a comprehensive market assessment, in which we analyze DC distribution field deployments and their end-use characteristics. We also conduct a survey of DC power and building professionals through on-site visits and phone interviews and summarize lessons learned and recommendations. In addition, the paper includes a novel efficiency analysis, in which we quantify energy savings from DC distribution for different end-use categories. Based on our findings, we present specific adoption pathways for DC in buildings that can be implemented today, and for each pathway we identify challenges and offer recommendations for the research and building community.

Detrimental effects exerted by biomass-based traditional cookstoves on health, environment, hygiene, and the soaring price of gas makes it imperative to investigate the feasibility of electric cooking as a promising clean cooking fuel in the context of Bangladesh. However, the adoption of electric cooking is unlikely to be welcomed if the monthly cost of electricity consumed by the electric cooking appliances is not comparable to traditional cooking fuels. So far, no study has been reported in this respect. Therefore, this paper is aimed to assess the energy consumption of available electric cooking appliances for cooking typical Bangladeshi dishes. Estimated monthly electricity cost of electric cooking is also reported and then compared to that of traditional cooking fuels. For the study purpose, three respondent families were provided with a rice cooker, hot plate, induction cooker and electric pressure cooker for cooking their daily meals. After four months of use, data related to dish cooked, amount of food, cooking time, and energy consumption were collected which shows that hot plate and rice cooker were the least preferred appliances due to their poor workmanship and limited use respectively. On the contrary, despite the fact that electric pressure cookers cannot perform all types of frying, it was the most preferred appliance owing to its ability to significantly reduce the cooking time and its less energy consumption. Induction cooker was less preferred for the additional requirement of compatible cook pots. The study also reveals that monthly energy requirements for electric cooking varied from 72–87 kWh corresponding to a cooking electricity bill ranging from BDT 504–609 per month (USD 6–7.5) which is less expensive as compared with biomass and LPG based cooking. This paper also highlights the prospects and challenges associated with the adoption of electricity as the primary cooking fuel in Bangladesh.

Digital and intelligent buildings are critical to realizing efficient building energy operations and a smart grid. With the increasing digitalization of processes throughout the life cycle of buildings, data exchanged between stakeholders and between building systems have grown significantly. However, a lack of semantic interoperability between data in different systems is still prevalent and hinders the development of energy-oriented applications that can be reused across buildings, limiting the scalability of innovative solutions. Addressing this challenge, our review paper systematically reviews metadata schemas and ontologies that are at the foundation of semantic interoperability necessary to move toward improved building energy operations. The review finds 40 schemas that span different phases of the building life cycle, most of which cover commercial building operations and, in particular, control and monitoring systems. The paper’s deeper review and analysis of five popular schemas identify several gaps in their ability to fully facilitate the work of a building modeler attempting to support three use cases: energy audits, automated fault detection and diagnosis, and optimal control. Our findings demonstrate that building modelers focused on energy use cases will find it difficult, labor intensive, and costly to create, sustain, and use semantic models with existing ontologies. This underscores the significant work still to be done to enable interoperable, usable, and maintainable building models. We make three recommendations for future work by the building modeling and energy communities: a centralized repository with a search engine for relevant schemas, the development of more use cases, and better harmonization and standardization of schemas in collaboration with industry to facilitate their adoption by stakeholders addressing varied energy-focused use cases.

Background COVID-19 outbreak has drawn out institutions to closure with several challenges for university students of undergraduate level in Dhaka city including an emergency shift from traditional learning to online learning, which associated digital divide, left several arguments in response to technological inefficiency, pedagogic inefficiency of teachers, inappropriate study environment and so on. Previous literature shows that the COVID-19 is imposing a threat to mental health all over the nation since its spread. This study intended to evaluate the emerging reasons for psychological distress among university students of undergraduate level in Dhaka, also assess the execution methods, barriers of online learning, and lastly, the attitudes of students regarding online learning throughout the pandemic. Methods A mixed methodology was used to conduct the research. Primary data has been collected using simple purposive sampling on 180 undergraduate students, 9 interviews were taken including 6 in-depth interviews of different university undergraduates from Dhaka city and also 3 (KIIs) from specialists of pedagogy and medical anthropology, and a high official from Bangladesh Telecommunication Regulatory Commission (BTRC). Results Based on the Kessler K-10 distress scale, the study found that the prevalence of no psychological distress (16.67%) followed by mild (40%), moderate (30.56%), and severe psychological distress (12.78%). Conclusion The results concluded considering several reasons for mild to severe psychological distress. The findings suggest some recommendations to accumulate the process of online learning effectively and also strategies to regulate the preferred mode of learning in future.

Bangladesh is one of the hardest-hit countries of the SARS-CoV-2 "COVID-19" outbreak. Evidence suggests the whole nation is facing a range of mental issues due to COVID-19 pandemic. The purpose of the current study is to investigate the level of psychological distress that emerged due to the ongoing COVID-19 pandemic among university students of Bangladesh. The study comprised quantitative data from 815 university students and qualitative data from 6 in-depth interviews of university students and 2 key informants specialized in education and medical anthropology. The quantitative data transcribed using the Kessler K-10 distress scale. In terms of psychological stress findings, 19.02% of students did not have any psychological distress, 29.20% reported moderate psychological distress, 33.01% reported high psychological distress and 18.77% reported very high psychological distress. The findings indicated those who have shown moderate to severe psychological distress have faced some degree of gender-based violence, economic crisis, and digital deprivation. Based on the findings, the research advocates multifaceted initiatives to reduce gender-based abuse and bridge the digital gap.

Purpose The present study was intended to investigate whether monocyte immune activation shapes plasma positive to negative acute phase reactants (APRs) ratio and predicts disease severity in dengue infection. Methods Serum level of ferritin, ceruloplasmin and transferrin was measured by means of electrochemiluminescence and immunoturbidimetry, respectively. Gene expression and plasma level for TNF-α, IL-6 and IL1-β was measured by means of RT-qPCR and ELISA. Results A significant increased serum ferritin to transferrin [6.6 (3–11.7) vs 3.4 (1.9–6.1)] and ceruloplasmin to transferrin ratio [0.48 (0.21–0.87) vs 0.22 (0.13–0.43)] has been detected among the subjects with secondary dengue infection (SDENI) compared to primarily infected (PDENI) subjects (P Conclusion Acute proinflammatory cytokine response is significantly associated with increased positive to negative APRs ratio in SDENI patients, which predicts intense immune activation, and renders SDENI patients extremely susceptible to hemostatic derangement.

Toxic chemicals are not only destructive for the world but also highly harmful for all living beings. However, these chemicals have a wide range of household and industrial applications. So, their controlled and precise use must be ensured. Strychnine, Potassium Cyanide, and Sodium Cyanide are highly toxic chemicals that may cause severe harm, even death, to human. Detection of these chemicals, maintaining safety, is a burning need. PCF offers a wide range of chemical sensing application possibilities. We have presented a PCF based toxic chemical sensor model in this paper. The sensor is specially modelled to detect Strychnine, Potassium Cyanide, and Sodium Cyanide. The proposed model offers approximately 84.52%, 88.64%, and 96.76% relative sensitivity for Potassium Cyanide, Sodium Cyanide and Strychnine respectively at 1.0 THz in x-polarization direction. Besides, the model preserves satisfactory values for the effective material and confinement loss as well as standard value for the effective area. Moreover, this sensor may be fabricated, practicing existing schemes of fabrication.

We have proposed a photonic crystal fiber (PCF) based sensor to sense toxic carbonyl air droplet found in cigarette smoke. A circular lattice PCF has been designed with four air holes ring in the cladding region and the circular shaped core used for analyte fill-up. In the proposed PCF, elliptical air holes are also used in the cladding region to improve guiding properties of the PCF. The commercial software COMSOL Multiphysics 5.3a has been used to simulate the entire geometry and to find out different optical parameters such as relative sensitivity, confinement loss, effective material loss (EML) and effective mode area at frequency range of 0.5 THz–1.5 THz. To find out the optimal geometrical conditions of the proposed PCF sensor, cladding air holes strut has been varied. At optimal conditions, simulation result shows that maximum relative sensitivity of 69%, 72%, 74% has been achieved for acetone, acrolein and nicotine respectively. The confinement loss of $4.19 \times 10^{-7}\text{cm}^{-1}, 8.46 \times 10^{-8} \text{cm}^{1-},\ 2.51 \times 10^{-9} \text{cm}^{-1}$ has been achieved for acetone, acrolein and nicotine respectively. The obtained effective material loss and effective mode area also comparable with recently reported PCF sensor. We strongly believe that by exiting fabrication technology, the proposed PCF sensor will be feasible for fabrication.

Research in miniaturization of devices is driven by the presence of new challenges in small-sized particles. Magnetic interactions at the heterostructure interface, specifically the interface-drive...

Since 2008, Bangladesh has had a school-based deworming programme to combat soil-transmitted helminth (STH) infection among school-aged children (SACs). Existing programmes have trouble reaching SACs, especially those out-of-school (OSCs). This study evaluated deworming coverage among school going children (SGCs) and OSCs in two Nilphamari sub-districts. It also evaluated community knowledge on STH control and deworming coverage in both areas for all SACs. Saidpur (intervention) and Kishoregonj (control) sub-districts, in Nilphamari, were surveyed in December 2019. The survey included SACs and their parents. Among SGCs, the intervention group (89.0%) had higher deworming coverage than the control group (75.5%). In the intervention group, 59.9% of OSCs received the deworming tablet versus 24.6% in the control group. Community involvement activities including door-to-door visits, courtyard gatherings, and miking benefited both SACs and their primary caregivers. SACs living in the intervention region, awareness of the last pill distribution date, and caregivers observing BRAC workers in action, were linked to SAC deworming coverage. Re-strategizing the deworming programme to include the OSCs is vital and suggests timely action. Building community awareness and periodic epidemiological assessment can further facilitate an improved drug intake.

Background: Malaria is one of the most severe public health problems worldwide. India contributes a substantial burden of malaria. It can cause several complications. Aims and Objectives: This study was conducted to determine the association of parasitemia of current malaria with age of patients, hemoglobin level, liver function test (LFT), platelet count, previous history of malaria, and relapse/recrudescence of malaria up to 1 year. Materials and Methods: An observational study conducted in hospital settings included thin and thick smear preparation with Leishman’s staining to determine the parasitemia as per the WHO guidelines from the blood samples of 280 malaria parasite dual antigen (MPDA) kit positive patients and their details were taken during study period of 2 years. Hemoglobin, LFT, and platelet count were tested and they were correlated with parasitemia. The previous history of malaria was taken and follow-up was done up to 1 year for relapse/recrudescence and their association with parasitemia in current disease was evaluated. Statistical tool R was used for data analysis. Results: Age group 20–40 years was most commonly affected with maximum mean percentage parasitemia. Higher parasitemia was associated with higher grade of anemia, LFT derangement, and thrombocytopenia. Disease severity was maximum for mixed infection followed by falciparum and vivax malaria. About 9.28% of patients with the previous history of malaria developed lower parasitemia in current infection. Relapse rate in vivax malaria –2.325% and recrudescence rate in falciparum malaria–12.5%. Conclusion: Malaria parasitemia should be reported routinely as it carries prognostic importance.

In recent years, significant efforts have been made to develop e-fuels from renewable electricity and carbon sources for enabling highly efficient and advanced propulsion systems. Compared to conventional fuels, such fuels can have very different thermo-physical properties depending on their molecular structure. Particularly, fuels with high vapor pressures are highly susceptible to flash boiling depending on boundary conditions, which can significantly alter the spray formation and mixing behavior. Thus, it becomes imperative to develop a fundamental understanding of the underlying physics associated with the flash boiling of these fuels in a single droplet configuration. In this work, oxymethylene ethers (OME x ) are chosen as a generic example to study the flashing behavior of newly developed e-fuels. This study employs the Lagrangian Particle Tracking (LPT) approach considering both internal and external vaporization of flash boiling single droplets. The internal vaporization model includes several sub-models that compute bubble number density, bubble growth rate, and droplet bursting criterion. External vaporization is modeled considering heat transfer from the droplet interior to the droplet surface and from the surrounding gas to the droplet surface. The study reveals that the formation and subsequent growth of vapor bubble nuclei is the primary source causing the transition of the metastable liquid phase into the stable state. We found that for moderate to high superheating degree, the bubble growth characteristics indicate three distinct growth phases: (1) surface tension-controlled, (2) transition, and (3) inertia-controlled, whereas, for low superheating degree, only two of these were present, namely (1) surface tension-controlled, and (2) transition phase. It is also observed that the chain length of OME x has significant impact on bubble dynamics. OME4 is found to have a larger critical nucleus, a longer time delay in bubble growth, and a slower growth rate compared with dimethyl ether (DME). Furthermore, a quantitative analysis shows that droplets burst earlier with increasing superheating degree. In addition, it is found that the system pressure has a negligible influence on the initiation of the bursting process, except when the superheating degree is very low.

Investigation of the magnetism of dilute magnetic semiconductors (DMSs) by changing particle dimensionality and doping concentration and its complete understanding is a major step toward their application in multifunctional devices. The importance of effects, such as magnetization reversal with size and magnetic invariance with respect to doping concentration for an appropriate functioning of DMS systems, is empirically well-known. However, explicit demonstration of these effects, specifically in nanomaterials, has so far not been studied mainly due to the lack of synthetic handle. In this work, we have demonstrated the prerequisites of DMS materials by isolating origins of magnetism arising due to clustering of magnetic dopant ions as well as sp–d exchange interaction with the host. We have studied magnetism with varying concentrations of dopant ions and have shown that the magnetism arising due to exchange interaction with the host is invariant up to 10% doping concentration, demonstrating the concentra...

The demonstration of the quantum confinement effect in colloidal quantum dots (QDs) has been extensively studied and exploited mainly in Pb and Cd chalcogenide systems. There has been an urgent need recently for the development of non(less)-toxic colloidal QDs to warrant compliance with current safety regulations (Restriction of Hazardous Substances (RoHS) Directive 2002/95/ EC). Herein, we report Pb/Cd-free, solution processed luminescent Ag2ZnSnS4 (AZTS) colloidal QDs. We present a selective and controlled amine and thiol-free synthesis of air stable luminescent AZTS QDs by the hot injection technique. By controlling the reaction conditions we obtain controlled size variation and demonstrate the quantum confinement effect that is in good agreement with the theoretically calculated values. The band gap of the AZTS QDs is size-tunable in the near-infrared from 740 to 850 nm. Finally, we passivate the surface with Zn-oleate, which yields higher quantum yield (QY), longer lifetime, and better colloidal stability

The solar PV Module yields optimum power under Standard Testing Conditions (STC) and hence generates the standard I-V characteristic curve. But in practical cases, this power is reduced due to various environmental effects. One of the main factors that is directly responsible for this degradation of output power is partial shading. Partially shaded cells produce less current than other normal cells exposed to sunlight and behave like a reverse biased p-n junction. As a result, it dissipates power instead of generating and gets heated. Consequently, hotspots are generated which results in reduced open circuit voltage. Therefore, the solar PV module produces less output power than it is supposed to. This paper investigates the temperature gradient that exists between a normally exposed cell and a shaded cell and the degradation in output power caused by the partial shading on the solar PV module. For comparative analysis, two identical PV panels have been taken with one of the panels being shaded partially. Different experimental data has been analyzed through PSpice software to notice how partial shading affects the solar PV panel. Also, PSpice simulation has been done to distinguish the impact of bypass diode in terms of PV output improvement. The phenomenon has also been realized by using a thermal camera and the result has been verified experimentally.

Dual doping is a powerful way to tailor the properties of semiconductor quantum dots (QDs) arising out of host-dopant and dopant-dopant interactions. Nevertheless, it has seldom been explored due to a variety of thermodynamic challenges, such as the differential bonding strength and diffusion constant within the host matrix that integrates with the host in dissimilar ways. This work discusses the challenges involved in administering them within the constraints of one host under similar conditions of temperature, time, and chemical parameters such as solubility and reactivity using CoPt-doped CdS QDs as a model system. In addition, the various forces in play, such as Kirkendall diffusion, solid- and liquid-state diffusion, hard acid soft base interaction with the host, and the effect of lattice strain due to lattice mismatch, are studied to understand the feasibility of the core to doped transformation. These findings suggest a potential approach for manipulating the properties of semiconductors by dual doping engineering.

Home energy management (HEM) systems are getting increasingly popular in both academic and commercial communities. Most HEM solutions rely on either smart appliances or plugging traditional appliances into smart outlet/smart plugs which can communicate with the central HEM server. Conventional non-communicating power-intensive loads that are directly hard-wired to the supply panel of the house in the U.S., e.g., water heaters and clothes dryers, therefore are difficult to be made part of an HEM system. This paper describes the design and implementation of a microcontroller and ZigBee based load controller system that allows these loads to be controlled by an HEM system. The proposed system consists of four load controllers (LCs) that monitor and control four power-intensive household loads, and one communication controller (CC) that acts as a communication medium between LCs and a central HEM unit. The CC and all the LCs are packaged into one load controller box that can be placed beside the main circuit panel of the house and the wirings to the power-intensive loads are routed through the LCs. Within the box, the LCs and the CC communicate via hard-wired serial peripheral interface. The CC then communicates with the HEM system via ZigBee. The proposed system is expected to offer a cost-effective method to enable traditional hard-wired power intensive loads to participate in an HEM system.

Internal structure study at an atomic level is a challenging task with far reaching consequences to its material properties, specifically in the field of transition metal doping in quantum dots. Diffusion of transition metal ions in and out of quantum dots forming magnetic clusters has been a major bottleneck in this class of materials. Diffusion of the magnetic ions from the core into the nonmagnetic shell in a core/shell heterostructure architecture to attain uniform doping has been recently introduced and yet to be understood. In this work, we have studied the local structure variation of Fe as a function of CdS matrix thickness and annealing time during the overcoating of Fe3O4 core with CdS using X-ray absorption spectroscopy. The data reveals that Fe3O4 core initially forms a core/shell structure with CdS followed by alloying at the interface eventually completely diffusing all the way through the CdS matrix to form homogeneously Fe-doped CdS QDs with excellent control over size and size distributio...

Effective manipulation of magnetic spin within a semiconductor leading to a search for ferromagnets with semiconducting properties has evolved into an important field of dilute magnetic semiconductors (DMS). Although a lot of research is focused on understanding the still controversial origin of magnetism, efforts are also underway to develop new materials with higher magnetic temperatures for spintronics applications. However, so far, efforts toward quantum-dots(QDs)-based DMS materials are plagued with problems of phase separation, leading to nonuniform distribution of dopant ions. In this work, we have developed a strategy to synthesize highly crystalline, single-domain DMS system starting from a small magnetic core and allowing it to diffuse uniformly inside a thick CdS semiconductor matrix and achieve DMS QDs. X-ray absorption fine structure (XAFS) spectroscopy and energy-dispersive X-ray spectroscopy-scanning transmission electron microscopy (STEM-EDX) indicates the homogeneous distribution of magnetic impurities inside the semiconductor QDs leading to superior magnetic property. Further, the versatility of this technique was demonstrated by obtaining ultra large particles (∼60 nm) with uniform doping concentration as well as demonstrating the high quality magnetic response.

BackgroundThe health status of Rohingya refugees or Forcibly Displaced Myanmar Nationals (FDMNs), especially women and children, is a significant challenge for humanitarian workers in Bangladesh. Though the Government of Bangladesh, in partnership with other organizations, is offering health care services to FDMNs, a comprehensive understanding of the program implementation is required for continuation in the future. This study explores the challenges and potential solutions for effective implementation of maternal, newborn, and child health (MNCH) programs for FDMNs residing in camps of Cox's Bazar, Bangladesh.MethodsWe conducted a qualitative study conducted in Cox's Bazar district, Bangladesh, which involved 34 interviews (15 key informant interviews and 19 in-depth interviews) with relevant persons working in organizations responsible for MNCH services to FDMNs. We relied on both inductive and deductive coding and applied the Consolidated Framework for Implementation Research (CFIR) as a guide to our thematic analysis and presentation of qualitative data.ResultsOur study identified some key challenges hindering the effective implementation of MNCH service delivery for the FDMNs. High turnover and poor retention of staff, overlapping of service, weak referral mechanism, complex health information system, and lack of security of the front line health providers were some of the key challenges identified. Motivating the health workers, task shifting, capacity building on emergency obstetric care, training CHW & TBA on danger signs, and ensuring the security of the workers are the potential solutions suggested by the respondents. Selecting a few indicators and the introduction of E-tracker can harmonize the health information system.ConclusionProviding healthcare in an emergency setting has several associated challenges. Considering the CFIR as the base for identifying different challenges and their potential solutions at a different level of the program can prove to be an excellent asset for the program implementers in designing their plans. Two additional domains, context, and security should be included in the CFIR framework for any humanitarian settings.

In Bangladesh, Solar Home Systems (SHS’s) are usually designed to meet the night loads. The panel generates energy and stores it in the battery during the daytime. To add autonomy to the system, both the panel and battery are oversized so that the load demand can be met for a certain period even if there is no energy production from the solar panel due to the unavailability of sunlight caused by cloudy weather. But, it is seen that during the dry season (February-April), due to the availability of sufficient sunlight and high clearness index, the autonomy rarely needs to be considered. Therefore, the extra energy produced by the panel to meet the autonomy remains unutilized which results in a highly inefficient energy management system. This paper investigates the total excess energy wasted during this period of the year. Using a PSpice model, the total energy waste for a 130 W p SHS has been simulated. Then considering the total installed capacity of SHS (232 MW) it has been found that almost 49330 MWh of solar energy is annually wasted in Bangladesh which results in a loss of almost 18.5 million USD/year. To compensate this loss, few possible ways of utilizing this energy for economic benefit has also been discussed.

A building energy management (BEM) system is a core hardware/software platform that enables demand response applications for building operators in the smart grid environment. This paper presents the BEM algorithm that is designed to be robust against communication failures and data errors. It has been implemented in the smart building located at Yildiz Technical University in Istanbul, Turkey, and results are reported herein. Appliance usage profiles and customer preferences used in the BEM demonstration were derived from a survey of Turkish customers. Both summer and winter usage profiles were used to validate the efficacy of the proposed algorithm in a real-world smart building environment. The paper also discusses lessons learned from field implementation.

The present study was aimed to investigate the relation between nuclear factor kappa beta (NFκB) activation and downstream up-regulation of vascular endothelial growth factor (VEGF) in diabetic retinopathy (DR). Moreover the study was intended to evaluate the role of VEGF gene single nucleotide polymorphisms (SNPs) in DR occurrence and to investigate the functional relevance of VEGF gene SNPs in terms of VEGF expression in DR. Serum level of VEGF, VEGF R1 (receptor 1), VEGF R 2 (receptor 2) and NFκB (p50/65) activity was measured by enzyme linked immune sorbent assay. Genotyping and allelic composition of different SNPs i.e., rs2010963, rs3025039, rs1570360 and rs 2071559 were investigated by Taqman SNP genotyping assay. VEGF, NFκB p50/p65, and VEGF R1 & R2 gene expressions were quantified by real time quantitative polymerase chain reaction. Increased NFκB p50/p65 activity and expressions were observed in non proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) subjects compared to type 2 diabetes mellitus without retinopathy (DNR) group. Significantly elevated levels of serum VEGF and highest VEGF expression were found among PDR subjects compared to DNR or NPDR subjects. CC genotype and C allele of rs2010963 and TT genotype and T allele of rs3025039 were significantly over represented among PDR subjects compared to DNR group. Increased activation of NFκβ in NPDR and PDR subjects might involve increased up regulation of VEGF. VEGF SNPs i.e., rs2010963 C allele and rs3025039 T allele might be associated with PDR occurrence and in turn regulates VEGF expression among PDR subjects.

Engineering interfaces specifically in quantum dot (QD) heterostructures provide several prospects for developing multifunctional building block materials. Precise control over internal structure by chemical synthesis offers a combination of different properties in QDs and allows us to study their fundamental properties, depending on their structure. Herein, we studied the interface of magnetic/nonmagnetic Fe3O4/CdS QD heterostructures. In this work, we demonstrate the decrease in the size of the magnetic core due to annealing at high temperature by the decrease in saturation magnetization and blocking temperature. Furthermore, surprisingly, in a prominently optically active and magnetically inactive material such as CdS, we observe the presence of substantial exchange bias in spite of the nonmagnetic nature of CdS QDs. The presence of exchange bias was proven by the increase in magnetic anisotropy as well as the presence of exchange bias field (HE) during the field-cooled magnetic measurements. This exch...

The potential of nanomaterials arises from the fine tuning of material properties by changing their composition, size and shape. Here, we show that by varying the local Cd and Te/S environment using CdTe/CdS as the host, a highly promising photovoltaic material can be easily converted to an efficient photo-emitting material. Thus we demonstrate for the first time that the internal structure can be used to tune the properties of the nanomaterial leading to competing and contrasting applications.