419 research outputs found

    Computer Simulation Results from System Dynamics Model of Agriculture System

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    This paper discusses the results of simulation from an extensive System Dynamics model of agriculture system. A computer simulation model is written in Dynamo with System Dynamics techniques to study the complex agriculture system using data from a number of case studies of India. The results presented in this paper are obtained from the simulation of the system with different infrastuctral and technological investment strategies. The results are summerised here which may be used as a basic plannining guidelines for developing large scale agriculture particularly in developing countries. These guidelines may be used to make such a project a successful venture rather than a waste as has already happened in a number of cases

    A System Dynamics Model for Automation

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    A system dynamics model is presented in this paper along with the results of simulation of some policies and their consequences automation. The automation seems to be the answer for faster growth and development throughout the world whether or not there is excessive labor or its shortage in a nation. Higher productivity, lower costs, better quality of products and services, remaining competitive and new innovations are benefits of automation and they are very important factors in industrialization and as well as in sustaining the jobs in the long run. Very often, particularly in the developing countries, the politicians either exploit or in most cases misunderstand the total effects of automation and computerization. In India, for example, computerization of even very important services like airlines and trail reservations, insurance and banking have suffered due to political decisions for two decades. Only recently they have realized their mistakes and are trying to catch up. This simple system dynamics model can be easily used for systems analysis to study the effects of automation and thus can help in making strategic decisions in automation and policy guidelines formulations

    A System Dynamics Model For Evaluating Investment Strategies for Agriculture Development

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    This paper presents a System Dynamics model to analyze the consequences of investments in agriculture. The data is taken from the various case studies of agriculture in India and is used as an example in the simulation model. A number of investment strategies are simulated to see the performence of the overall system. Some results are presented from the simulation providing insight into the intricacies of the system variables which may be used as guidelines for investing large funds in agro-projects to maximise the benefits and to reduce the undesired consequences. The model can be used to study the effects of changes in one or more controllable variables in the performance of the system. It provides insight into the system variables which are important in making the planning a success and to optimize the profits from the investments. The paper describes in detail the system dynamics flow diagram of the agriculture system model, the factors which are important for investments to be profitable

    Electrical, Thermal and Spectroscopic Characterization of Bulk Bi2Se3 Topological Insulator

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    We report electrical (angular magneto-resistance, and Hall), thermal (heat capacity) and spectroscopic (Raman, x-ray photo electron, angle resolved photo electron) characterization of bulk Bi2Se3 topological insulator, which is being is grown by self flux method through solid state reaction from high temperature (950C) melt and slow cooling (2C/hour) of constituent elements. Bi2Se3 exhibited metallic behaviour down to 5K. Magneto transport measurements revealed linear up to 400% and 30% MR at 5K under 14 Tesla field in perpendicular and parallel field direction respectively. We noticed that the magneto-resistance (MR) of Bi2Se3 is very sensitive to the angle of applied field. MR is maximum when the field is normal to the sample surface, while it is minimum when the field is parallel. Hall coefficient (RH) is seen nearly invariant with negative carrier sign down to 5K albeit having near periodic oscillations above 100K. Heat capacity (Cp) versus temperature plot is seen without any phase transitions down to 5K and is well fitted (Cp = gammaT + betaT3) at low temperature with calculated Debye temperature (ThetaD) value of 105.5K. Clear Raman peaks are seen at 72, 131 and 177 cm-1 corresponding to A1g1, Eg2 and A1g2 respectively. Though, two distinct asymmetric characteristic peak shapes are seen for Bi 4f7/2 and Bi 4f5/2, the Se 3d region is found to be broad displaying the overlapping of spin - orbit components of the same. Angle-resolved photoemission spectroscopy (ARPES) data of Bi2Se3 revealed distinctly the bulk conduction bands (BCB), surface state (SS), Dirac point (DP) and bulk valence bands (BVB) and 3D bulk conduction signatures are clearly seen. Summarily, host of physical properties for as grown Bi2Se3 crystal are reported here.Comment: 6 Pages Text + Figs; Comments Suggestions welcom

    Incorporating Ion-Specific van der Waals and Soft Repulsive Interactions in the Poisson-Boltzmann Theory of Electrical Double Layers

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    Electrical double layers (EDLs) arise when an electrolyte is in contact with a charged surface, and are encountered in several application areas including batteries, supercapacitors, electrocatalytic reactors, and colloids. In the modeling of EDLs, a prominent knowledge gap has been the exclusion of van der Waals (vdW) and soft repulsive interactions in modified Poisson-Boltzmann (PB) theories. Although more short-ranged as compared to electrostatic interactions, we show here that vdW interactions can play an important role in determining the structure of the EDL via the formation of a Stern layer and in modulating the differential capacitance of an electrode in solution. To this end, we incorporate ion-ion and wall-ion vdW attraction and soft repulsion via a 12-6 Lennard-Jones (LJ) potential, resulting in a modified PB-LJ approach. The wall-ion LJ interactions were found to have a significant effect on the electrical potential and concentration profiles, especially close to the wall. However, ion-ion LJ interactions do not affect the EDL structure at low bulk ion concentrations (< 1 M). We also derive dimensionless numbers to quantify the impact of ion-ion and wall-ion LJ interactions on the EDL. Furthermore, in the pursuit of capturing ion-specific effects, we apply our model by considering various combinations of ions. We observe how varying parameters such as the electrolyte concentration and electrode potential affect the structure of the EDL due to the competition between ion-specific LJ and electrostatic interactions. Lastly, we show that the inclusion of vdW and soft repulsion interactions as well as hydration effects lead to a better qualitative agreement of the PB models with experimental double-layer differential capacitance data. Overall, the modified PB-LJ approach presented herein will lead to more accurate theoretical descriptions of EDLs in various application areas

    Comparative study of functional and radiological outcomes of the usage of two devices, derotation type cephalomedullary nail and the helical blade type in unstable intertrochanteric fractures in the geriatric population at a tertiary-level center

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    Background: Intertrochanteric fracture is a common osteoporotic fracture among elderly populations in an aging society. Early surgical fixation on these aging patients has been proposed recently for early rehabilitation and has had a positive impact on reducing comorbidities. For unstable fractures, intramedullary implants generally present biomechanical advantages over their extramedullary counterparts. Methods: The study was a 2 years prospective comparative study from 1st December 2020 to 1st December 2022 conducted in the department of orthopaedics, Rajendra institute of medical sciences, Ranchi, Jharkhand, India. Total number of patients were 50, PFN done in 25 cases and PFN-A2 in another 25 cases. Results: Mean age is 64.4 years in PFN group as compared to 67.3 years in PFN-A2 group. PFN-A2 was done in 84% male while PFN in only 76 % male and in both groups right side was mostly affected. Average surgery time, amount of blood loss, average number of C-arm shoot was more in PFN group. Conclusions: In this study of 50 patients, 25 treated by PFN and 25 by PFN-A2, it was concluded that PFN-A2 was a better construct to treat patients of older age group having osteoporosis because here reaming was not done and helical blade was inserted by hammering which caused compaction of bones in head and neck region

    Prospective review of open reduction and internal fixation with Kirschner wires (K-wires left exposed) fixation in displaced and rotated (Song V) lateral humerus condyle fractures in children

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    Background: Fractures of the lateral condyle of the humerus account for 10-15% of all elbow fractures in children. These include Salter Harris type 2 and type 4 growth plate injuries in which the fracture crosses the distal humeral growth plate and enter the elbow joint. Open reduction and internal fixation with K wire is treatment of choice for the displaced as well as minimally displaced lateral condyle fractures of children to prevent malunion, nonunion and further displacement. Methods: This was prospective analytical study conducted in Rajendra Institute of Medical Sciences, Ranchi from December 2020 to December 2022 which consisted of 30 patients (of whom only 27 were present for follow ups) who were treated by ORIF with K-wires fixation. We followed the classification pattern given by Song et al. Results were evaluated according to the criteria given by the Hardacre et al. Results: Major culprit for injuries was fall from height (44.4%), followed by playing indoor games (25.9%). RTA and sports each constituted of (14.8%). Functional outcomes based on Hardacre criteria are excellent (85.1%), good in 11.1% cases and fair in 3.7% cases. Conclusions: Our findings demonstrate that open reduction and internal fixation with 2 or 3 K-wires (which were left exposed) and immobilization with casting for 3-4 weeks is sufficient for most of displaced and rotated fractures of the lateral condyle of the humerus

    Clinical spectrum of paediatric head injury: A prospective study from tribal region

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    Introduction: Traumatic Brain injury is considered as a major health problem which causes frequent deaths and disabilities in paediatric population with special concern to tribal regions of developing countries like India where etiology of traumatic brain injury in the paediatric population fall from height dominant over the road traffic accident as a major. Aim and objective: The aim is to analyse the epidemiology, mechanism, clinical presentation, severity and outcome of paediatric head injury in the tribal region of northern India that could help to make preventive policies to improve their care. Material methods: It is a prospective observational study of 345 children of up to 18 years of age admitted under Department of Neurosurgery from October 2017 to April 2019. Results: The study population comprised of 345 paediatric patients. Mean age was 9.25 years.36.81% patients were in 1-6-year age group and male to female ratio was 2.45. The most common cause for trauma was fall from height in 179(52%) cases followed by RTA in 141(41%) cases. The most common radiological finding was depressed skull fractures in 97(50%) cases. There was 35% mortality in severe head injury patients. Conclusion: This study through some light on the different scenario of head injury in Tribal regions of Developing country and will help to formulate effective strategies for prevention and better care of the patients

    Clinical spectrum of paediatric head injury. A prospective study from tribal region

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    Introduction: Traumatic brain injury is considered as a major health problem which causes frequent deaths and disabilities in the paediatric population with special concern to tribal regions of developing countries like India where aetiology of traumatic brain injury in the paediatric population fall from height dominant over the road traffic accident as a major. Aim &amp; Objective: The aim is to analyse the epidemiology, mechanism, clinical presentation, severity and outcome of paediatric head injury in the tribal region of northern India that could help to make preventive policies to improve their care. Material Methods: It is a prospective observational study of 345 children of up to 18 years of age admitted under Department of Neurosurgery from October 2017 to April 2019. Results: The study population comprised of 345 paediatric patients. Mean age was 9.25 years.36.81% patients were in 1-6-year age group and male to female ratio was 2.45. The most common cause for trauma was fall from height in 179(52%) cases followed by RTA in 141(41%) cases. The most common radiological finding was depressed skull fractures in 97(50%) cases. There was 35% mortality in severe head injury patients. Conclusion: This study through some light on the different scenario of head injury in Tribal regions of Developing country and will help to formulate effective strategies for prevention and better care of the patients

    Development of Microfluidic, Serum-Free Bronchial Epithelial Cells-on-a-Chip to Facilitate a More Realistic In vitro Testing of Nanoplastics

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    Most cell culture models are static, but the cellular microenvironment in the body is dynamic. Here, we established a microfluidic-based in vitro model of human bronchial epithelial cells in which cells are stationary, but nutrient supply is dynamic, and we used this system to evaluate cellular uptake of nanoparticles. The cells were maintained in fetal calf serum-free and bovine pituitary extract-free cell culture medium. BEAS-2B, an immortalized, non-tumorigenic human cell line, was used as a model and the cells were grown in a chip within a microfluidic device and were briefly infused with amorphous silica (SiO2) nanoparticles or polystyrene (PS) nanoparticles of similar primary sizes but with different densities. For comparison, tests were also performed using static, multi-well cultures. Cellular uptake of the fluorescently labeled particles was investigated by flow cytometry and confocal microscopy. Exposure under dynamic culture conditions resulted in higher cellular uptake of the PS nanoparticles when compared to static conditions, while uptake of SiO2 nanoparticles was similar in both settings. The present study has shown that it is feasible to grow human lung cells under completely animal-free conditions using a microfluidic-based device, and we have also found that cellular uptake of PS nanoparticles aka nanoplastics is highly dependent on culture conditions. Hence, traditional cell cultures may not accurately reflect the uptake of low-density particles, potentially leading to an underestimation of their cellular impact
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