Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger

Ground source heat pump (GSHP) systems are becoming popular in space heating and cooling applications. Despite this fact, in most countries, the role of this energy is not as important as it should be nowadays according to its capabilities for energy generation without CO2 emissions, mainly due to the lack of technical knowledge about GSHP performance. The analysis of the physical processes that take part in the geothermal exchanges is necessary to allow the optimal exploitation of the geothermal resources. For all the above, an experimental geothermal device was built in the laboratory to control the phenomena that take place in a borehole heat exchanger (BHE). A 1-m high single-U heat exchanger was inserted in the center of a polyethylene container which also included granular material (surrounding ground) and the grouting material. Temperature sensors were situated in different positions of the experimental setup. Physical processes are evaluated to finally validate the model. Numerous applications can be developed from the experimental BHE. In this research, the determination of the thermal conductivity of the material used as medium was carried out. Results of this parameter were also compared with the ones obtained from the use of the KD2 Pro device.

Development of Technology and Equipment for Ultrasonic Planimetric Welding of Polyethylene Products

The specifics of ultrasonic planimetric welding of polyethylene containers of irregular shape filled with foodstuff are considered in this work. A planimetric wave guide that can be used for welding polyethylene containers of a large diameter (up to 120 mm) and thickness ranging from 0.4 to 1.5 mm is proposed and implemented. The issue of obtaining high-quality leak-tight weld joints with stable mechanical properties on the surface of a polyethylene container exposed to corrosive environment is resolved. Various shapes of the working surface of the planimetric wave guide are developed, making it possible to weld containers with good appearance, durability and leak-tightness. A scheme for welding containers by a planimetric wave guide with an acoustic screen is proposed. The results of studies to determine the optimal parameters for the modes of ultrasonic planimetric welding are presented. The shape, material and position of the support in relation to the planimetric wave guide are defined. The technology and equipment for ultrasonic planimetric welding of polyethylene cans of a large diameter filled with various substances and foodstuff are developed. As the result of the research, all the studied liquids are divided into three groups depending on their influence on weldability.

Pre-packing cooling and types of packages in maintaining physiological quality of soybean seeds during storage

Seeds storing under appropriate conditions reduces the speed of the seeds deterioration process. The aim of this study was to evaluate pre-packing cooling and types of packages in the maintenance of the physiological quality of soybean seeds during storage. The completely randomized experimental design was used, with four replications, considering a factorial arrangement involving or not the pre-packing cooling of the seed mass, three types of packages (multi-layer paper bag, big bag, and polyethylene container), and five storing periods (0, 2, 4, 6 and 8 months). The physiological quality was evaluated by the tests of first germination count, germination, accelerated aging, electrical conductivity, emergence speed index and emergence. The use of packages with larger amount of seeds (big bag and polyethylene container) did not favor the maintenance of the pre-packing cooling temperature. The types of packages did not show significant differences in the seeds viability during storage, up to eight months, regardless the pre-packing cooling. The cultivars seeds showed different tolerance to storing, i.e. seeds of the cultivar TMG 1176 had lower storing potential comparing to the seeds from the cultivar SYN 9074.

Effect of Humic Acid on Growth of `Muskogee' Crape Myrtle after Container Shielding Treatments

Rooted cuttings of crepe myrtle (Lagerstroemia indica L. × L. fauriei `Muskogee') were transplanted into 3.8-L black polyethylene containers filled with a bark-based rooting substrate and exposed for 2 months during Summer 1995 to either of three container shielding treatments: containers shielded from insolation (container shielded inside a whitewashed 11.4-L black polyethylene container), containers exposed to insolation, or containers shielded for 1 month then exposed for 1 month. Mean highest temperature in the western quadrant of rooting substrate of exposed containers was 16°C higher than for those in shielded containers. Containers exposed for 2 months had reduced root and shoot growth and increased leaf N compared with the other two treatments. Crape myrtle plants were next transplanted into 27.0-L polybags, transferred into a temperature-controlled glasshouse, and fertigated to container capacity every 3 days with humic acid extract at concentrations of 0, 50, 150, or 300 μl·L–1 for 2 additional months. Effects of the container shielding treatments for all growth parameters remained evident until the end of the experiment. Shoot and root extension growth of plants previously in containers shielded for 2 months and containers exposed for 2 months, responded in a quadratic fashion to humic acid extract concentration levels.