Understanding and Design of an Arduino-based PID Controller

This thesis presents research and design of a Proportional, Integral, and Derivative (PID) controller that uses a microcontroller (Arduino) platform. The research part discusses the structure of a PID algorithm with some motivating work already performed with the Arduino-based PID controller from various fields. An inexpensive Arduino-based PID controller designed in the laboratory to control the temperature, consists of hardware parts: Arduino UNO, thermoelectric cooler, and electronic components while the software portion includes C/C++ programming. The PID parameters for a particular controller are found manually. The role of different PID parameters is discussed with the subsequent comparison between different modes of PID controllers. The designed system can effectively measure the temperature with an error of ± 0.6℃ while a stable temperature control with only slight deviation from the desired value (setpoint) is achieved. The designed system and concepts learned from the control system serve in pursuing inexpensive and precise ways to control physical parameters within a desired range in our laboratory

Ligand Effects on Electronic, Magnetic, and Catalytic Properties of Clusters and Cluster Assemblies

Ligands commonly protect metallic clusters against reacting with outside reactants. However, ligands can also be used to control the redox properties enabling the formation of super donors/acceptors that can donate/accept multiple electrons. This thesis focuses on how the ligands can be used to control the electronic and magnetic features of clusters and ligand stabilized cluster-based assemblies, leading to nano pn junctions with directed transport, the possibility of light-harvesting, and catalysts for cross-coupling reactions. The thesis addresses three distinct classes of clusters and their applications. The first class of cluster “metal chalcogen clusters” is the central idea of the thesis focused on recent experiments where metal-chalcogenide clusters have been stabilized in solutions, where clusters assemblies have been synthesized by combining them with counter ions. We also investigate the fusion of metal-chalcogenide clusters leading to nano pn-junctions with immense dipole moments and their potential applications in photovoltaics and spintronics. We then investigate simple metal clusters and show how ligands can control the ionization characteristics of aluminum-based clusters and how assemblies of such clusters linked through organometallic wires can form dimer with a significant dipole moment enabling directed transport, applicable in photovoltaics. Finally, we demonstrate how transition metal (palladium-based) clusters adsorbed on double vacant graphene, reduced graphene oxide, and graphene-acid-based supports catalyze cross-coupling reactions in different ligand environments. The graphene supports can also be realized as the solid-state ligands for cross-coupling reactions

Climate Change Impacts and Adaptation in a Hill Farming System of the Himalayan Region: Climatic Trends, Farmers’ Perceptions and Practices

Farming communities in the hills and mountains of the Himalayan region are some of the most vulnerable to the changing climate, owing to their specific biophysical and socioeconomic conditions. Understanding the observed parameters of the changing climate and the farmers’ perceptions of it, together with their coping approaches, is an important asset to making farming communities resilient. Therefore, this study aimed to explore the observed change in climatic variables; understand farmers’ perceptions of the changing climate; and document their adaptation approaches in farming systems in the mid-hills of the central Himalayas. Data on the observed change in climatic variables were obtained from the nearby meteorological stations and gridded regional products, and farmers’ perceptions and their adaptation practices were collected from household surveys and from the interviews of key informants. The analysis of temperature data revealed that there has been a clear warming trend. Winter temperatures are increasing faster than summer and annual temperatures, indicating a narrowing temperature range. Results on precipitation did not show a clear trend but exhibited large inter-annual variability. The standardized precipitation index (SPI) showed an increased frequency of droughts in recent years. Farmers’ perceptions of the changing climate are coherent with the observed changes in climatic parameters. These changes may have a substantial impact on agriculture and the livelihood of the people in the study area. The farmers are adapting to climate change by altering their farming systems and practices. Location-specific adaptation approaches used by farmers are valuable assets for community resilience

Climate Change Impacts and Adaptation in a Hill Farming System of the Himalayan Region: Climatic Trends, Farmers’ Perceptions and Practices

Farming communities in the hills and mountains of the Himalayan region are some of the most vulnerable to the changing climate, owing to their specific biophysical and socioeconomic conditions. Understanding the observed parameters of the changing climate and the farmers’ perceptions of it, together with their coping approaches, is an important asset to making farming communities resilient. Therefore, this study aimed to explore the observed change in climatic variables; understand farmers’ perceptions of the changing climate; and document their adaptation approaches in farming systems in the mid-hills of the central Himalayas. Data on the observed change in climatic variables were obtained from the nearby meteorological stations and gridded regional products, and farmers’ perceptions and their adaptation practices were collected from household surveys and from the interviews of key informants. The analysis of temperature data revealed that there has been a clear warming trend. Winter temperatures are increasing faster than summer and annual temperatures, indicating a narrowing temperature range. Results on precipitation did not show a clear trend but exhibited large inter-annual variability. The standardized precipitation index (SPI) showed an increased frequency of droughts in recent years. Farmers’ perceptions of the changing climate are coherent with the observed changes in climatic parameters. These changes may have a substantial impact on agriculture and the livelihood of the people in the study area. The farmers are adapting to climate change by altering their farming systems and practices. Location-specific adaptation approaches used by farmers are valuable assets for community resilience

Magic Numbers in Octahedral Ligated Metal-Chalcogenide Superatoms

The attainment of the superatomic state offers a unifying framework for the periodic classification of atomic clusters. Metallic clusters attain the superatomic state via the confined nearly free electron gas model that leads to groupings of quantum states marked by radial and angular momentum quantum numbers. We examine ligated octahedral metal-chalcogenide clusters where the nearly free electron gas model is invalid; however, the high symmetry can also lead to the bunching of electronic states. For octahedral TM6E8L6 clusters (TM = transition metal; E = chalcogen; L = ligand), the electronic shells are filled for valence electron counts of 96, 100, and 114 electrons. These magic electron counts are marked by large highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gaps, high ionization energies, and low electron affinityall classic signatures of the superatomic state. We also find that clusters with electron counts differing from the magic counts show periodic patterns reminiscent of those observed in the periodic table of elements

Electron transport properties of PAl12-based cluster complexes

The electronic transport properties of PAl12-based cluster complexes are investigated by density functional theory (DFT) in combination with the non-equilibrium Green\u27s function (NEGF) method. Joining two PAl12 clusters via a germanium linker creates a stable semiconducting complex with a large HOMO-LUMO gap. Sequential attachment of an electron-donating ligand, N-ethyl-2-pyrrolidone, to one of the two linked clusters results in the shifting of the electronic spectrum of the ligated cluster while the energy levels of the unligated cluster are mostly unchanged. Using this approach, one can eventually align the HOMO of the ligated cluster to the LUMO of the non-ligated cluster, thereby significantly reducing the HOMO-LUMO gap of the complex. As a result, the transport properties of the complex are highly dependent on the number of attached ligands. Although a single ligand is observed to generally decrease the current, the inclusion of two or more ligands shows a significant increase in the amount of current at most voltages. The resulting increase of the current can be attributed to two factors, first the reduction in the HOMO-LUMO gap due to ligand attachment which has moved the transmission orbitals into the bias window. Secondly, when two or more ligands are attached to the complex, the HOMOs become delocalized across the scattering region, and this significantly enhances the currents. This journal i

Knowledge on Pesticide Handling Practices and Factors Affecting Adoption of Personal Protective Equipment: A Case of Farmers from Nepal

Globally, the use of pesticide is growing day by day, but the use of PPE in developing countries is still low and farmers are directly exposed to chemicals which have negative health issues. Thus, this study was conducted in different places of Nepal where the use and adoption of chemical pesticide is high. This study aims on assessment of pesticide handling practices and determinants of adoption of PPE where 281 respondents were interviewed by the simple random sampling technique. A binary logit model was used to predict the determinants for adoption of PPE while spraying pesticides. Schooling years, training, reading label, and buying pesticide by name are the determining factors in adoption of PPE at 1% level of significance in the logit model. Still, the pesticide handling practices followed by farmers are not satisfactory and proper protective clothes are not used while spraying pesticides. Thus, to protect from different health issues, training, seminars, and talk discussion should be scheduled regarding safe pesticide handling practices and adoption of PPE. Also, the use of biopesticides should be encouraged as they are most promising and ecofriendly

Impact of a structured yoga program on blood pressure reduction among hypertensive patients: study protocol for a pragmatic randomized multicenter trial in primary health care settings in Nepal

Abstract Background Hypertension control remains a major global challenge. The behavioral approaches recommended for blood pressure reduction are stress reduction, increased exercise and healthy dietary habits. Some study findings suggest that yoga has a beneficial effect in reducing blood pressure. However, the role of yoga on blood pressure has received little attention in existing health care practices in developing countries. This study will be conducted in primary health care facilities in Nepal to assess the effectiveness of a pragmatic yoga intervention to complement standard practice in further reducing blood pressure. Methods This will be multicentric, two arms, randomized, nonblinded, pragmatic trial. It will be conducted in seven District Ayurveda Health Centers (DAHCs) in Nepal between July 2017 and June 2018. The study participants will consist of hypertensive patients with or without antihypertensive medication attending to the outpatient department (OPD). One hundred and forty participants will be randomized to treatment or control groups by using a stratified block randomization. At the study site, the treatment arm participants will receive an intervention consisting of five days of structured yoga training and practice of the same package at home with a recommendation of five days a week for the following 90 days. Both the intervention and control groups will receive two hours of health education on lifestyle modifications. The primary outcome of this trial will be the change in systolic blood pressure and it will be assessed after 90 days of the intervention. Discussion This study will establish the extent to which a yoga intervention package can help reduce blood pressure in hypertensive patients. If proven effective, study findings may be used to recommend the governing bodies and other stakeholders for the integration of yoga in the national healthcare system for the treatment and control of hypertension. Trial registration Clinical Trial Registry- India (CTRI); CTRI Reg. No- CTRI/2017/02/007822. Registered on 10/02/2017

An outbreak investigation of visceral leishmaniasis among residents of Dharan town, eastern Nepal, evidence for urban transmission of <it>Leishmania donovani</it>

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL) is a predominantly rural disease, common in the low lands of eastern Nepal. Since 1997 VL cases have also been reported among residents of the city of Dharan. Our main research objective was to find out whether there had been local transmission of VL inside the city.</p> <p>Methods</p> <p>We conducted an outbreak investigation including a case–control study; cases were all urban residents treated for VL between 2000 and 2008 at BP Koirala Institute of Health Sciences, a university hospital in the city. For each case, we selected four random controls, with no history of previous VL; frequency-matched for age. Cases and controls were subjected to a structured interview on the main exposures of interest and potential confounders; a binominal multilevel model was used to analyze the data. We also collected entomological data from all neighborhoods of the city.</p> <p>Results</p> <p>We enrolled 115 VL patients and 448 controls. Cases were strongly clustered, 70% residing in 3 out of 19 neighborhoods. We found a strong association with socio-economic status, the poorest being most at risk. Housing was a risk factor independent from socio-economic status, most at risk were those living in thatched houses without windows. ‘Sleeping upstairs’ and ‘sleeping on a bed’ were strongly protective, OR of 0.08 and 0.25 respectively; proximity to a case was a strong risk factor (OR 3.79). Sand flies were captured in all neighborhoods; in collections from several neighborhoods presence of <it>L</it>. <it>donovani</it> could be demonstrated by PCR.</p> <p>Conclusion</p> <p>The evidence found in this study is consistent with transmission of anthroponotic VL within the city. The vector <it>P</it>. <it>argentipes</it> and the parasite <it>L</it>. <it>donovani</it> have both been identified inside the town. These findings are highly relevant for policy makers; in VL endemic areas appropriate surveillance and disease control measures must be adopted not only in rural areas but in urban areas as well.</p