Results 1 - 10 of 93
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[en] Radiation protection personnel sets have been classified into a recycle and a disposal by the process of rad-survey and laundry. Most of all, a large number of protection clothes have been accompanied with some difficulties in making an inventory. To improve the problem, we have a plan to employ a database program to keep track of those information such as contamination, inventories, daily logs ets.. We could expect the program to make the process simple as well as promote the radiation safety management work in more effective way
[en] This study is carried out to get the high flowrate of a Heat-Exchanger (HE) fan through an optimum condition of a fan casing. The control factors in the present study are the orifice inlet diameter, the orifice inlet clearance, the cut-off angle, and the cut-off clearance. The goal of this study is to select the best combination of each control factor of the HE fan casing with a minimum variability and to obtain a linear relationship between the flowrate and the number of revolution. Thus, the parameter design of the Taguchi method is adopted for robust design by a dynamic characteristic analysis using orthogonal arrays and S/N ratios. The flowrate measurements are conducted by using a small-sized fan tester according to the orthogonal array L9(34). In the present study, the flowrate under an optimum condition having a set of < A2 B3 C3 D1> satisfies with the linear equation y=0.0039 · M as to the number of revolution, and the flowrate is improved by about 44.4 (%) as compared with the current condition
[en] Puffing is an attractive alternative for the production of healthy crisp snacks without frying. Although image analysis has been used in some prior studies to evaluate puffing, such an evaluation was made only in one or two dimensions, which is inadequate when a sample deforms in three dimensions. In this study, use of combined hot-air and microwave drying to dry and puff banana slices was first evaluated. Algorithms were then developed to characterize the changes in the appearance of puffed banana slices. Various image-based parameters, both in two and three dimensions were assessed and used to monitor the puffing. (Author)
[en] Energy from microalgae is one of the growing alternatives for traditional energy sources. However, the economic viability of processing microalgae for energy has been a major concern thus far. Microalgae slurry, typically with 85-95% initial moisture content, is perishable and must be processed immediately after harvest but drying alone will be responsible for 25-30% of the total production cost. Utilizing a solar dryer would improve the yield of the production. The study investigates the solar radiation heat transfer inside the microalgae solar dryer and determines available heat to the microalgae in the drying chamber as well as describes the airflow profile of air inside the solar dryer using the ANSYS CFD software. ANSYS CFX package was utilized to mesh and solve for the numerical solution. The drying chamber design based from Forson et al (2007) is coupled to a single-pass flat plate air heater to drive the air flow through natural convection. The simulation of the drying process of the microalgae involves heat transfer inside the solar dryer and employs the Monte Carlo thermal radiation model in a steady-state solution. Air domain temperature is set to 30°C, based on the average ambient temperature in Manila. Based on the material selected, the walls of the solar chamber are set to allow thermal radiation with a heat transfer coefficient of 50 W/m2 K. The floor of the chamber was assigned to be an adiabatic wall. Also, a constant velocity of 1 m/s at the air outlet was set to account for the density gradient at the chimney and to eliminate stagnation points inside the dryer for the initial run. The numerical results gave a maximum and minimum velocity of 1.11 m/s and 0.28 m/s. The achieved temperature range inside the drying chamber was comparable to the data published by Prakash et al. (1997). The resulting profile showed that the geometry causes air from the main flow to partially re-circulate. This is significant since residence time of air inside the drying chamber could prove to be a noteworthy factor to consider in future studies. (author)
[en] The studies present convective drying of parsley with an intermittent microwave application. Eight different drying programs including convective drying (CV) were carried out in a laboratory-scale hybrid dryer. The influence of intermittent conditions on drying time, drying rate, energy efficiency and product quality was analysed. The results demonstrated that intermittent–microwave convective drying improves the drying kinetics and reduces energy consumption. Moreover, a higher retention of vitamin C, smaller color change and a better ability to rehydration were observed for the parsley samples dried using intermittent drying than for CV. (Author)
[en] The search for solutions to transform the by-products generated by the agri-food sector in high value-added ingredients is a priority. The aim of this research was to develop a microwave coupled with hot air drying technique allowing maximizing profits by reducing time and operational costs and to produce a dietary fiber ingredient with interesting technological properties for the development of healthy foods. The shrinkage-swelling phenomena occurred during drying changed the rehydration properties of the fibre ingredient obtained. An increase in particle size improved the fibre's swelling capacity when hydrated, allowing 50 % fat substitution in potato purees. (Author)
[en] Highlights: • The solar dryer for wood proposed is very simple to construct. • This dryer using a solar collector is mathematically modeled. • The solar collector efficiency is experimentally validated. • The modeling can be used to perform many others solar dryers. • The effect of solar collector on the final wood water content is important. - Abstract: The main objective of this paper is to develop a computational model and to simulate the drying of timber with a solar dryer. Two sets of equations have been established: one for the solar collector and the other for the drying chamber. The computed and measured outlet temperatures of the solar collector were compared. A very satisfactory prediction by the model is observed. The theoretical variations of the relative humidity and temperature of the air inside the drying chamber were computed and the analyses gave satisfactory physical meanings. The drying kinetic is a little faster. Using the solar collector, the final moisture content of the wood stack of iroko species (Chlorophora excelsa) is lower than the one obtained without utilization of the solar collector. The proposed modelling can be used to design and model other solar dryers.
[en] A method and apparatus are disclosed for continuously drying and regenerating ceramic beads for use in process gas moisture drying operations such as glove boxes. A microwave energy source is coupled to a process chamber to internally heat the ceramic beads and vaporize moisture contained therein. In a preferred embodiment, the moisture laden ceramic beads are conveyed toward the microwave source by a screw mechanism. The regenerated beads flow down outside of the screw mechanism and are available to absorb additional moisture
[en] Improvements in the energy efficiency of household appliances have the potential to decrease residential energy use, but these reductions accrue gradually over time as newer appliances replace older models. SHEU-2003 data are used to examine appliance replacement patterns in Canada for refrigerators, freezers, dishwashers, clothes washers and clothes dryers. The data indicate that the ages at which appliances are replaced tend to be lowest for dishwashers and highest for freezers, with over 40% of freezers in use for more than 20 years before being retired. The life spans of Canadian appliances are compared to the underlying assumptions regarding appliance lifetimes used in models of residential energy demand. We find that Canadian appliance retirement patterns differ from those assumed in the previous literature. Socioeconomic factors related to appliance replacement are also examined. We find that replacement patterns can be sensitive to household characteristics such as income, providing evidence that there may be scope for targeted policies aimed at inducing earlier replacements of older household appliances with new energy-efficient models
[en] There exists considerable evidence that manufacturing costs and consumer prices of residential appliances have decreased in real terms over the last several decades. This phenomenon is generally attributable to manufacturing efficiency gained with cumulative experience producing a certain good, and is modeled by an empirical experience curve. The technical analyses conducted in support of U.S. energy conservation standards for residential appliances and commercial equipment have, until recently, assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. This assumption does not reflect real market price dynamics. Using price data from the Bureau of Labor Statistics, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These experience curves were incorporated into recent energy conservation standards analyses for these products. Including experience curves increases the national consumer net present value of potential standard levels. In some cases a potential standard level exhibits a net benefit when considering experience, whereas without experience it exhibits a net cost. These results highlight the importance of modeling more representative market prices. - Highlights: ► Past appliance standards analyses have assumed constant equipment prices. ► There is considerable evidence of consistent real price declines. ► We incorporate experience curves for several large appliances into the analysis. ► The revised analyses demonstrate larger net present values of potential standards. ► The results imply that past standards analyses may have undervalued benefits.