Effects of irradiation on the rate of water vapor transmission of food packaging materials

Food can be preserved by irradiation which is the exposure of food to ionising radiation, high energy electron from electron beams or X-rays or gamma rays from Cobalt-60 or Cesium-137 radioisotopes. Irradiation does not leave a residue in the food and it does not make it radioactive. The low level energy levels of Cobalt and Cesium isotopic gamma rays does not induce any radioactivity. Irradiation has the same preservative effect on food as heat treatment, but because irradiation does not appreciably raise the temperature of the food, it is known as \u27cold sterilization\u27. Irradiation can potentially be used to preserve fresh meat, poultry, sea food, vegetables, fruits, grain and other foods which harbor disease causing microorganisms and also extend shelf-life. Other potential advantages include replacement of chemical fumigation to control insect infestation of grains, cereals, flour, fruits and vegetables, and partial replacement of food additives such as nitrite in cured meat. One of the characteristic advantages of the irradiation process is that the product can be irradiated after it has been placed within its container, and sealed so that recontamination after processing is prevented. It is not possible for the product itself to become radioactive, and there are no residue of any kind left by the process. Once treated, foods are ready for use or consumption. Irradiation can cause changes in the physical properties of some packaging materials which alters the strength, color, sealability, or barrier properties of the materials hence this study was to confirm the effects of irradiation on the rate of water vapor transmission of the food packaging materials selected for the test

Investigation of fiber/matrix adhesion: test speed and specimen shape effects in the cylinder test

The cylinder test, developed from the microdroplet test, was adapted to assess the interfacial adhesion strength between fiber and matrix. The sensitivity of cylinder test to pull-out speed and specimen geometry was measured. It was established that the effect of test speed can be described as a superposition of two opposite, simultaneous effects which have been modeled mathematically by fitting two parameter Weibull curves on the measured datas. Effects of the cylinder size and its geometrical relation on the measured strength values have been analyzed by finite element method. It was concluded that the geometry has a direct influence on the stress formation. Based on the results achieved, recommendations were given on how to perform the novel single fiber cylinder test

Methodological Investigations on a Neuropteroidea Community

The same Neuropteroidea community was collected and studied in Hungary in the years 1991 and 1992 by using different trapping techniques: a) Malaise trap, b) suction trap, c) yellow pan trap and d) light trap. The studies aimed to compare the different sampling methods for individual species, families and for the whole Neuropteroidea community. In case the whole Neuropteroidea community the trapped individual numbers collected by the suction trap surpassed all other trap types. Relatively high numbers of Neuropteroidea could be collected both by light trap and Malaise traps. The yellow pan traps did not succeed in catching large enough samples neither from point of view of sample size nor from species richness. According to the number of species collected there were not discovered any big difference between the catches of suction trap, Malaise traps and light trap. By evaluating according to families it was stated that in case of the family Raphidiidae the Malaise trap yielded larger and more diverse samples than any other methods; however by increasing the number of yellow pan traps it is possible to augment the number of caught individuals. The suction traps were found very satisfactory in collecting members of the family Coniopterygidae. For the members of the families Hemerobiidae and Chrysopidae both the suction traps and light traps were found effective, although suction traps were more successful in collecting Chrysopidae species. Similarly, by evaluating the data according to individual species it was found that the Malaise traps tended to “under-represent” species belonging to Hemerobius humulinus, Hemerobius Lutescens, Chrysopa pallens and the ones belonging to Chrysoperla carnea complex compared to the suction trap. The opposing situation was perceived with Micromus lanosus and Chrysopa perla. Similarly – compared to suction trap – the light trap significantly “under-represented” the species Hemerobius humulinus, Hemerobius lutescens, Chrysopa pallens, Chrysoperla carnea and Dichochrysa prasina and “over-represented” Micromus angulatus, Sympherobius pygmaeus and Chrysopa phyllochroma. The diversity of Neuropteroidea collected by Malaise trap and light trap surpassed significantly the one of suction trap and yellow pan traps. The assemblages collected by different sampling methods showed some overlapping, but differed in their characters

Electrodynamic tethers for spacecraft propulsion

Relatively short electrodynamic tethers can use solar power to "push" against a planetary magnetic field to achieve propul sion without expenditure of propellant. The groundwork has been laid for this type of propulsion. Recent important milestones include retrieval of a tether in space (TSS-1, 1992), successful deployment of a 20-km-long tether in space (SEDS-1, 1993), and operation of an electrodynamic tether with tether current driven in both directions (PMG, 1993). The planned Propulsive Small Expendable Deployer System (ProSEDS) experiment will use the flight-proven Small Expendable Deployer System (SEDS) to deploy a 5-km bare copper tether from a Delta II upper stage to achieve -0,4 N drag thrust, thus deorbiting the stage, The experiment will use a predominantly "bare" tether for current collection in lieu of the endmass collector and insulated tether approach used on previous missions, Theory and ground-based plasma chamber testing indicate that the bare tether is a highly efficient current collector. The flight experiment is a precursor to utilization of the technology on the International Space tation (JSS) for reboost and the electrodynamic tether pper stage demonstration misión which will be capable of orbit raising, lowering, and inclination changes—all using electrodynamic thrust. In addition, the use of this type of propulsion may be attractive for future missions to Jupiter

Feedup, feedback, and feedforward in curve mid-air 3D gestures

Issuing a mid-air gesture in a three-dimensional space intrinsically suffers for the lack of explicit direct representation of the gesture with which guidance and feedback can be offered. To address this challenge, we decompose the feedback problem into three components: feedup to constantly represent the goal of the gestural task, feedback to respond to what the end user already did related to the initial goal, and feedforward to modify the representation towards the ultimate goal before terminating the gesture production. We exemplify these three components with case studies representing three levels of complexity of Curve Mid-Air 3D Gestures produced in three environments