107 research outputs found
sj-docx-1-mdm-10.1177_0272989X221097106 – Supplemental material for Trends in Author-Reported Cost-Effectiveness Thresholds in the United States from 1995 to 2018: Implications for Discount Rates
No full textSupplemental material, sj-docx-1-mdm-10.1177_0272989X221097106 for Trends in Author-Reported Cost-Effectiveness Thresholds in the United States from 1995 to 2018: Implications for Discount Rates by Ankur Pandya, Mike Paulden, Jinyi Zhu, Tara A. Lavelle and James Hammitt in Medical Decision Making</p
Embodied energetics : a digital design-production system for passive solar walls in Vinalhaven Island, Maine
No full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M., Massachusetts Institute of Technology, Department of Architecture, 2019Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 102-105).I propose a digital design-production system to easily assemble, selectively disassemble, and reassemble novel passive solar walls. The problem statement I tackle is that all houses in Vinalhaven Island, Maine have high home-heating energy burden due to their thermally weak thin walls. Substituting thin walls with typical passive solar walls is a known solution, however such walls would be inundated with (i) high embodied energy in non-recoverable materials, (ii) high complexity of construction, and (iii) high cost of construction and renovation. Facilitated by a CAD-CAM interface, I develop a methodological framework called Design for Assembly, Disassembly, and Reassembly to lower all three parameters efficiently. I demonstrate both the framework and its outcomes by rapidly prototyping a few study models of passive solar walls. I speculate on the urban implications of a widespread integration of walls with reduced and recoverable material embodied energy. In order to effectively visualize this, the system boundary of urbanism scales up from a wall to a house, to two adjacent houses, and finally to five houses in Vinalhaven's downtown. I claim that successful on-site substitution of today's standard walls with Digital Passive Solar Walls will accelerate Vinalhaven's island homes toward a holistic energy transition. Broadly, I encourage professionals in the building industry to embrace such digital systems to recover material embodied energy locked in their designed artifacts.by Ankur Podder.S.M.S.M. Massachusetts Institute of Technology, Department of Architectur
Nanoemulsions: formation, properties and applications
Get PDFNanoemulsions are kinetically stable liquid-in-liquid dispersions with droplet sizes on the order of 100 nm. Their small size leads to useful properties such as high surface area per unit volume, robust stability, optically transparent appearance, and tunable rheology. Nanoemulsions are finding application in diverse areas such as drug delivery, food, cosmetics, pharmaceuticals, and material synthesis. Additionally, they serve as model systems to understand nanoscale colloidal dispersions. High and low energy methods are used to prepare nanoemulsions, including high pressure homogenization, ultrasonication, phase inversion temperature and emulsion inversion point, as well as recently developed approaches such as bubble bursting method. In this review article, we summarize the major methods to prepare nanoemulsions, theories to predict droplet size, physical conditions and chemical additives which affect droplet stability, and recent applications.Eni S.p.A
Varietal Evaluation of Promising Maize Genotypes in Mid Hills of Nepal
Get PDFThe varietal evaluation of hybrid maize (Zea mays L.) genotypes with desired performance is one of the main objectives of maize breeding program. Fourteen hybrid maize genotypes were evaluated for 17 quantitative and nine qualitative traits in randomized complete block design with three replications at Sundarbazar, Lamjung, Nepal during May to September, 2019. The major objective was to identify superior genotypes based on genotypic and phenotypic variability, heritability, genetic advance, and correlation between grain yield and yield associated traits. We observed significant differences for 17 quantitative traits among the tested genotypes. Large variation was observed for grain yield among genotypes. Genotype RL-24-0/ RL-111 had the lowest yield (5.53 mt/ha) and Pioneer had the highest yield (11.98 mt/ha) whereas check variety Rampur Hybrid-10 yielded of 8.23 mt/ha. Grain yield showed highly significant positive correlations with stem girth (r= 0.67) and number of ears (r=0.6), but significant negative correlation with anthesis-silking interval (r= -0.55). The dendrogram grouped 14 genotypes into four clusters. Cluster I incorporated the highest number (five) of genotypes, which also had highest cluster mean (average yield of ~10 mt/ha) for grain yield. Traits namely test weight, ear aspect, anthesis-silking interval, number of ears, and tassel branching had high genotypic and phenotypic coefficient of variations, and heritability along with high genetic advances, indicating that these traits can be considered for maize breeding program
Cluster Analysis of Wheat (Triticum aestivum L.) Genotypes Based Upon Response to Terminal Heat Stress
No full textHigh temperature stress adversely affects plant physiological processes; limiting plant growth and reducing grain yield. Heat stress is often encountered due to late sowing of wheat in winter. Fifty wheat genotypes were studied for days to maturity, thousand kernel weight, grain filling duration, grain filling rate, and SPAD reading in alpha lattice design at Agriculture and Forestry University at Rampur, Chitwan, Nepal with the objective to identify superior heat stress tolerant varieties after clustering them based on their response to heat stress. All the genotypes were clustered using reduction in thousand kernel weight, heat susceptibility index for thousand kernel weight, heat susceptibility index for grain filling duration, area under SPAD retreat curve, maturity duration under normal condition, maturity duration at late sown condition, grain filling rate under normal condition and grain filling rate at late sown condition as variables and dendogram was prepared. UPGMA revealed that these genotypes formed five distinct clusters. The resistant genotypes and susceptible genotypes formed different clusters. The member of cluster 3 was found to be tolerant to terminal heat stress where as members of cluster 2 were found most susceptible to terminal heat stress. From this study genotype BAJ #1/SUP152 was found most tolerant to terminal heat stress. The genotypes belonging to superior cluster could be considered very useful in developing heat tolerant variety and other breeding activities.Int. J. Appl. Sci. Biotechnol. Vol 5(2): 188-193</jats:p
Accelerating circularity in Built-environment through "Active-procurement": An aggregated assessment framework to make sustainable choices while using secondary material at early design phase
No full textIn Europe, 1/3rd of all the products reaching recycling facilities can be sold as secondary materials, and this can be a high-quality replacement for low-quality new products. Circular Material Use rate shows how much material demand was catered by reused or recycled content. The Netherlands was estimated at 29% in 2016 is the highest among all other member states and more than twice of Europe’s average. The Netherlands has now set up the goal to become 100% circular by 2050. Principles of circularity aim at lowering the environmental impacts and halve the emissions by 2030 and carbon neutral by 2050, according to the Paris Agreement. However, even though high circularity rates in the Netherlands, 12.2 tonnes per capita of greenhouse gases were released in 2016, which is 3.5 tonnes higher than the EU average. In transitioning to a circular built environment, the most crucial challenge is to keep all materials in a closed loop in a way that proves lower environmental impact compared to extracting a virgin equivalent. In current practice, building materials are procured at the end of a design phase, which results in minimum use of secondary stock and maximum extraction of virgin material to fit “circular” designs. Since buildings are designed for longer lifespans, this virgin material returns as secondary much later and do not reflect in the indicator defined by the EU. The main question is what information is needed by a designer or engineer in procuring secondary materials and when & how it can be best provided to them. This research gives an Assessment Framework to assess parameters such as the circular flow of materials,embodied CO2, cost and technical performance while designing.It is composed of five significant interfaces - material database, material explorer, assessment dashboard, digital design and a visual script toassess various parameters such as MCI, embodied CO2, distance from the project site, cost, U-value, Thermal conductivity, Density and other labels in 3D.The framework provides a Preliminary and Advanced assessment of different parameters. The only difference is that Advanced assessment takes into account is the disassembly potential of various components at a system level and determines whether they can be reused or have to be demolished at EOL. Demolition would mean a product reach EOL sooner, which result in higher embodied CO2. Hence, allowing design/engineering optimization. Other instance, where a component reaches EOL before its surrounding product, replacement of that component should not result in the demolition of others.Architecture, Urbanism and Building Sciences | Building Technolog
Particle Manipulation using Microfluidics
No full textThe progress made by microfabrication technologies has escalated the interest in particle manipulation on micron scale. Particles are not only limited to solid particles but also include cells, droplets and bubbles. Activities involved in manipulation are trapping, sorting, separation and so on. The devices designed to execute such activities are aimed for a particular application. However, there lies a gap in literature to design an all-in-one device. Microfluidics research carried out at the Laboratory for Aero and Hydrodynamics is currently working on designing such devices which can carry out different manipulation tasks.This thesis is aimed at designing and fabricating such a device where two particles can be manipulated simultaneously. The application of designing such a device would be to study cell-cell interaction, droplet coalescence and so on. To achieve this, a microfluidic device is designed as a Hele-Shaw flow cell. Since the height-averaged velocity in a Hele-Shaw flow cell is irrotational, analytical solution is possible for such a design. Although a Hele-Shaw flow is viscous flow between two closely spaced plates, it produces same streamline patterns as a 2D ideal flow. This enables the use of basic building blocks of an ideal flow field such as sources, sinks, uniform flow and so on. In this case, sources and sinks are superimposed to get the flow field inside the microfluidic device. The microfluidic device is fabricated using Polydimethylsiloxane (PDMS), a commonly used polymer to fabricate microfluidic devices. The design of the device is validated by comparing experimental flow fields, streamlines and stagnation points to the corresponding analytical solution. Single particle manipulation activities are carried out in the device. This is executed by manually controlling the flow rates or the strength of sources and sinks. Firstly, the particle is trapped at the stagnation point for a certain timespan. Finally, some manipulation activities are carried out using a single particle with the aid of streamlines produced by the sources and sinks.Mechanical Engineerin
Synthesis and characterization of lanthanum complex (5-choloro-8-hydroxy quinoline) bis (2-2’bipyridine) lanthanum La(Bpy)2(5-Clq)
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