Test report, test results, operational ninety-day manned test of a regenerative life support system

Manned 90-day performance test of regenerative life support systems in space station simulator including crew biomedical test

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Aerospace Food Technology

Operational and technological problems of improvement in space flight feeding for future manned space mission

Drying characteristics of Saskatoon berries under microwave and combined microwave-convection heating

The study on dehydration of frozen saskatoon berries and the need for dried fruits has been strategically identified in the prairies. Our motivation was to find a suitable method for dehydration in order to extend saskatoon berry shelf life for preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities and also introduces solutes into the fruit that acts as a preservative and also reduces the total drying time. Due to the very short harvesting season of saskatoon berries, an accelerated process like microwave combination drying can bring down the moisture to safe storage level, immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80C) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed, built with temperature and moisture loss data acquisition systems using LabView 6i software. Thin-layer cross flow dryer was used for convection-only drying and for comparison. Drying kinetics of the drying processes were studied and curve fitting with five empirical equations including Page equation, was carried to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analysis by means of color changes, rehydration ratio measurements and observed structural changes with scanning electron microscope technique were the factors in drying method selection for saskatoon berries. This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials. Microwave-convection combination drying at 70oC, yields good results with higher drying rates and better end-product quality

Drying characteristics of Saskatoon berries under microwave and combined microwave-convection heating

The study on dehydration of frozen saskatoon berries and the need for dried fruits have been strategically identified in the Canadian Prairies. The motivation for this research was to find a suitable method for dehydration and extend saskatoon berry shelf life for long term preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration, using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities introducing solutes into the fruit that acts as a preservative and also reduces the total drying time. Due to the very short harvesting season of saskatoon berries, an accelerated process such as the microwave combination drying can reduce the moisture to safe storage levels immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80oC) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed with integrated temperature and moisture loss data acquisition systems using LabView 6i software. A thin-layer cross flow dryer was used for convection-only drying and for comparison. Drying kinetics of the process were studied and curve fitting with five empirical equations, including the Page equation, was carried out to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analyses were accomplished by measuring the color changes, rehydration ratio and any structural changes, using a scanning electron microscope technique.This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials (fruits). Microwave-convection combination drying at 70oC, yielded good results with higher drying rates and better end-product quality

Development of safe and ready to eat frozen oyster products using microwave steam-venting technology

The Gulf Coast region, principally Louisiana, leads the nation in oyster production. The National Marine Fisheries Service reported that 19.7 million pounds of oyster meat, valued at $62.3 million dollars were harvested from the Gulf Coast region in 2010. One of the main concerns for this industry is the health risk associated with the consumption of oysters, particularly for at-risk populations. Oysters are filter feeders. They tend to concentrate microbes present in surrounding waters, some of which can cause severe illness in susceptible humans. Among pathogens that contaminate the gastrointestinal system of oysters, Vibrio spp (especially V. parahaemolyticus and V. vulnificus) are of greatest concern. The overall goal of the proposed study was to develop a protocol for the production of high quality and safe frozen oyster products in steam venting packages that are microwavable. Based on this study, a combination of 100 g of frozen oyster meat with 200 g of frozen mixed vegetables provided retention of almost 95% of the meat’s moisture after 300 s of microwave cooking. In addition, the achieving of an internal temperature of 90°C after 258 s of microwave cooking assured inactivation of naturally occurring pathogenic bacteria in oyster meat. The study demonstrated that steam venting technology could be used to inactivate pathogenic bacteria in frozen oysters and oyster products cooked in the steam packages retained the texture and the desirable flavor composition traditionally associated with oysters

Conversion of landfill composite to activated carbon as an approach to sustainable landfill management

Landfilling of municipal solid waste is a major waste disposal method, especially in developing countries despite its pressing environmental challenges. Reuse of the landfill composite has been suggested as a sustainable management option that could limit its negative effect. This research evaluated the compositional trend and characteristics of landfill composites with depth in order to assess its suitability as a precursor for activated carbon. A bulk system classification was used during analysis of the composite parameters (‘more degraded’ and ‘less degraded’ components). Both landfills had similar waste constituents, but varied in relation to moisture, TOC, and heavy metals contents. The elemental and chemical constituents of an active and a closed landfill were compared using Fourier transform - infrared (FTIR) spectroscopy, scanning electron microscope/energy-dispersive X-ray (SEM/EDX) spectroscopy, and proximate analysis. The two landfills had similar major elemental constituents representing 96.5 % and 98.4 % of elemental composition for the closed (O > C > Si> Fe > Ca >Al) and active(C > O > Si > Al > Ca > Fe) landfill samples respectively. A single step chemical activation process of precursor was applied involving irradiation with microwave energy and KOH as the activation agent. The average percentage yield of activated carbon (AC) from active landfill precursor was higher than that from closed landfill for all three depths of sampling (upper, 23.8 and 19.3 %; mid, 52.4 and 34.7 %; lower 35.7 and 27.0 %). Methylene blue adsorption capacity and BET surface analysis indicated adsorption capacity and surface area of AC from degraded precursor increased with depth. All AC conformed to a multilayer adsorption model and a pseudo second order kinetic. Carbonyl and hydroxyl groups were the major functional group on the surface of activated carbon. The AC properties indicated that precursors from both landfills are potentially suitable for generation of adsorbent suitable for removal of cationic dyes and pollutants

The distribution and fate of chlorpropham in commercial potato stores

The thesis consists of a study of chlorpropham distribution patterns and its behaviour within tuber components in commercial potato stores in the UK. The store examined were both cold (3-4 °C) and conventional (8-10 °C) stores. As a large number of samples from different stores were taken, it was important to have a quick and reliable analytical method for chlorpropham determination. This was developed and compared against the original accepted method. Both methods were more or less similar in their precision of results, with recoveries of 83.80 2.25 and 93.14 3.51 from spiked samples by blending and reflux extracting methods respectively. When the methods were compared for extracting the amount of chlorpropham in commercially treated stored samples, it gave recoveries of 2.49 0.25 and 2.58 0.17 for the blending and reflux methods respectively. Overall the reflux extracting method was quicker and easier and it was used for further work with some slight modification. The present study showed that the level and distribution pattern of chlorpropham was significantly different within the store and as well as between different commercial stores. The overall range of chlorpropham levels in the examined stores was 2.11-236.56 mg/kg. The amount of chlorpropham varied with respect to sampling sites of the examined stores. Each store has its own distribution pattern with some similarities. However there was a common trending all the stores examined in that the maximum level of chlorpropham was on the top surface and minimum on the lower levels of the stores. In the cold store examined 'A' ( 3-4 °C) the level of chlorpropham decreased continuously from the top height towards the bottom height of the store. However the amount of chlorpropham was excessive throughout the store, even in the middle of the boxes it exceeded the MRL (Maximum Recommended Level). The level of chlorpropham dropped from 128.39 mg/kg in the middle layer samples of the top box to 49.14, 20.15, 19.01, 8.03 3.97 and 4.54 mg/kg towards the bottom boxes of a six high column of boxes in the store respectively

Microwave based monitoring system for corrosion under insulation

This thesis presents the work undertaken by the author within the institute of Signals, Sensors and Systems in the school of Engineering and Physical Sciences at Heriot-Watt University, Edinburgh. The main aim of the research was to design and develop a non-destructive sensor capable of monitoring the onset of corrosion under insulation. The development of the sensor has involved the design of a complete system to stabilise and control the sensor, the development of a COMSOL model to understand the progression of corrosion to determine the remaining useful life of the asset, and an investigation into horn antenna design to inform the design of the optimal sensor head. The designed sensor system was tested with a variety of samples to benchmark the effectiveness of the sensor and prove the concept viability as a product. Experiments proved the concept of sensing defects in metallic surface with or without insulation layers. Samples simulating real life corrosion were tested to prove the resilience of the sensor when defects were less guaranteed. Remaining useful life estimations were conducted on simulated defects to show the sensor ability to become a smart sensor using prognostic health management techniques. Finally the environmental tests were conducted to ensure the sensor was indeed nondestructive, confirming that all aspects of the research had been successfully completed