5,582 research outputs found

    3D Printing of Transparent Materials for Optical Applications

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    Additive manufacturing processes have been used to print a variety of polymer, metal, ceramic and composite materials for a rapidly growing range of functional applications involving printed electronics, embedded optical components and sensors. Additive manufacturing (or 3D Printing) techniques such as Stereolithography (SLA) and Inkjet Printing have been used to print stand-alone optical components and interactive optical devices respectively. To date, however, there has been relatively little focus on multi-material printing of components with embedded optical functionality. This research focuses on printing embedded light-transmitting ā€œpipesā€ within 3D structures using Fused Filament Extrusion (FFE) and inkjet 3D printing. With FFE, relatively low-cost parts can be printed using multiple transparent and translucent materials for applications such as illumination, light covers and light pipes. Direct functional assemblies for sensing, display and illumination components are better suited for the inkjet 3D printing processes which are generally capable of producing more accurate parts with higher resolution. A comparative study is performed for successful quantification of parameters affecting optical clarity and light transmission through printed embedded light pipes. Clear and opaque commercially available Acrylonitrile Butadiene Styrene (ABS) filament is used for the FFE process, whereas an acrylic based ink formulation is used for inkjet 3D printed parts. Printed light pipes are tested for light transmission (light intensity) using an exposure meter. The results show how light transmission through the printed light pipes is affected by printing parameter levels

    Static, Modal and Transient Analysis of Radial Arm using Ansys

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    A computational capability is evolved for the gold standard design of radial drilling gadget shape to satisfy static stress and natural frequency necessities the use of finite element idealization. The radial drilling device structure is idealized with body elements and is analyzed by way of the usage of specific combos of move sectional shapes for the radial arm and the column. From the consequences acquired, the best mixture of cross sectional shapes is recommended for the structure. With this mixture of cross-sectional shapes, mathematical programming strategies are used to find the minimal weight design of the radial drilling device shape. A sensitivity analysis is carried out about the most excellent factor to locate the consequences of adjustments in layout variables on the structural weight and the reaction quantities.3D Modeling in CREO parametric software program and evaluation in ANSYS software

    Livelihood Risk from HIV in Semi-Arid Tropics of Rural Andhra Pradesh

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    This paper discusses the livelihood dynamics in the fragile landscape of the semi-arid tropics (SAT) of Andhra Pradesh. SAT is home to the poorest of the poor who live in conditions of persistent drought, subsistence agriculture and poor access to markets. This paper is a case study focusing particularly on labour migration, its role in influencing the health risk behaviour of migrants and in the spread of the HIV epidemic among SAT rural households. The most vulnerable population in these drought prone regions are the migrant labourers, and their vulnerability is influenced by three major factorsā€”the vulnerability and unstable productivity in the degraded and marginal landscape, the caste system that has traditionally kept them backward and vulnerable, and experiences in the external environment to which they migrate. This study is based on a theoretical framework, whereby livelihood risks lead to health risks, particularly HIV infectionā€”outlines the process that causes a further deterioration of the household and the occurrence of cyclical health risk. The paper calls for a multisectoral approach to tackle the issue of migrant vulnerability, and for interventions with a more migrant-need sensitive approach.

    Livelihood Risk from HIV in Semi-Arid Tropics of Rural Andhra Pradesh

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    This paper discusses the livelihood dynamics in the fragile landscape of the semi arid tropics (SAT) of Andhra Pradesh. SAT is home to the poorest of the poor who live in conditions of persistent drought, subsistence agriculture and poor access to markets. This paper is a case study focusing particularly on labour migration, its role in influencing the health risk behaviour of migrants and in the spread of the HIV epidemic among SAT rural households. The most vulnerable population in these drought prone regions are the migrant labourers, and their vulnerability is influenced by three major factors?the vulnerability and unstable productivity in the degraded and marginal landscape, the caste system that has traditionally kept them backward and vulnerable, and experiences in the external environment to which they migrate. This study?based on a theoretical framework, whereby livelihood risks lead to health risks, particularly HIV infection?outlines the process that causes a further deterioration of the household and the occurrence of cyclical health risk. The paper calls for a multisectoral approach to tackle the issue of migrant vulnerability, and for interventions with a more migrant-need sensitive approach.labour migration, HIV risk behaviour, agriculture, health, semi-arid tropics

    Novel methods to estimate antiretroviral adherence: protocol for a longitudinal study.

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    BackgroundThere is currently no gold standard for assessing antiretroviral (ARV) adherence, so researchers often resort to the most feasible and cost-effective methods possible (eg, self-report), which may be biased or inaccurate. The goal of our study was to evaluate the feasibility and acceptability of innovative and remote methods to estimate ARV adherence, which can potentially be conducted with less time and financial resources in a wide range of clinic and research settings. Here, we describe the research protocol for studying these novel methods and some lessons learned.MethodsThe 6-month pilot study aimed to examine the feasibility and acceptability of a remotely conducted study to evaluate the correlation between: 1) text-messaged photographs of pharmacy refill dates for refill-based adherence; 2) text-messaged photographs of pills for pill count-based adherence; and 3) home-collected hair sample measures of ARV concentration for pharmacologic-based adherence. Participants were sent monthly automated text messages to collect refill dates and pill counts that were taken and sent via mobile telephone photographs, and hair collection kits every 2 months by mail. At the study end, feasibility was calculated by specific metrics, such as the receipt of hair samples and responses to text messages. Participants completed a quantitative survey and qualitative exit interviews to examine the acceptability of these adherence evaluation methods. The relationship between the 3 novel metrics of adherence and self-reported adherence will be assessed.DiscussionInvestigators conducting adherence research are often limited to using either self-reported adherence, which is subjective, biased, and often overestimated, or other more complex methods. Here, we describe the protocol for evaluating the feasibility and acceptability of 3 novel and remote methods of estimating adherence, with the aim of evaluating the relationships between them. Additionally, we note the lessons learned from the protocol implementation to date. We expect that these novel measures will be feasible and acceptable. The implications of this research will be the identification and evaluation of innovative and accurate metrics of ARV adherence for future implementation

    Characterising information correlation in a stochastic Izhikevich neuron

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    The Izhikevich spiking neuron model is a relatively new mathematical framework which is able to represent many observed spiking neuron behaviors, excitatory or inhibitory, by simply adjusting a set of four model parameters. This model is deterministic in nature and has achieved wide applications in analytical and numerical analysis of biological neurons due largely to its biological plausibility and computational efficiency. In this work we present a stochastic version of the Izhikevich neuron, and measure its performance in transmitting information in a range of biological frequencies. The work reveals that the deterministic Izhikevich model has a wide information transmission range and is generally better in transmitting information than its stochastic counterpart

    Optimization of vibration amplitude ratio of face mill tool of VMC and analysis with design expert to endorsing shim design

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    This paper presents the concept, design and development of shim (passive damper) to improve the stability for high spindle speed machine operation of face mill tool. The objective of this paper is to learning the dynamic behavior of a face mill tool on VMC with dissimilar types of shims which cover investigation of dynamic motion behavior of the face mill tool, the behavior of different types of shim design and behavior of vibration by using the amplitude ratio method and analysis by a Design Expert. Research work supported computational analysis with Ansys, 35 VMC experimental records and analyzed by ANOVA/Design Expert with different type of shims to observe a dynamic behavior of chatter. It include of the effect of process parameters like Cutting speed (250,200,150 m/min), feed per tooth (0.05, 0.1, 0.15mm/tooth), depth of cut (1.2 mm, 1.0 mm, 0.8 mm), and different types of materials (shims) for face mill tool on VMC, for analyzing the responses like amplitude ratio in X ā€“ direction, Y- direction with ANOVA and optimizing for AISI 2062 steel by Design Expert. An experimental methodology was developed using the DOE (Design of experiment) technique. The optimum factorial method was used to design an orthogonal array of four factors having three levels. Here, the main results are based on amplitude ratio, ANOVA analysis and optimization. ANOVA was used to decide the effects of the machining parameters on the vibration amplitude ratio in X; and vibration amplitude ratio in Y. This is useful for evaluating the stability of milling operations via time domain FFT and analyzed by ANOVA. Data are validated by 35 sets of VMC experiments. Physical 35 experiments may be not enough in a view of high level researchers, academicians and industrialist to conclude the use of shim and it need in face mill tool on VMC. Hence here optimization based on optimum factorial method is executed using Design Expert software in which 35experiments and its iterations with 70 populations were used to run the program. It is found that the most critical parameter in this study is the material of Shim. At high cutting parameters carbide shim, at low and medium cutting parameters SS shim are given better results by ANOVA and Optimization of Design Expert also validated by 35 sets of VMC experiments. Hence these shim designs endorse versatile solutions

    Legislatures and Legislative Politics without Democracy

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    What do authoritarian legislatures and legislators do? Would outcomes in dictatorships be different if they were absent? Why do dictatorships have legislatures in the first place? These questions represent central puzzles in the study of authoritarian politics and institutions. The introductory article to this special issue on legislatures in nondemocracies discusses what we now know about these assemblies; what the issueā€™s articles contribute to this body of knowledge; and what future work might fruitfully look at. The special issue as a whole aims to advance the research agendas of both authoritarian institutions and legislative studies
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