• Analytical Science and Technology
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• v.19 no.2
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• pp.131-141
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• 2006

Hydrobromic acid salt of a $N_2O_2$ tetradentate ligand, N,N'-bis(2-hydroxybenzyl)-ethylene-diamine ($H-BHE{\cdot}2HBr$) was synthesized. $Br-BHE{\cdot}2HBr$, $Cl-BHE{\cdot}2HBr$, $CH_3-BHE{\cdot}2HBr$ and $CH_3O-BHE{\cdot}2HBr$ having Br, Cl, $CH_3$ and $CH_3O$ substituents at 5-position of the phenol group of $H-BHE{\cdot}2HBr$ were also synthesized. $Nap-BHE{\cdot}2HBr$ having naphthalen-2-ol instead of the phenol group was also synthesized. The potentiometry study in aqueous solution revealed that the proton dissociations of the synthesized ligands occurred in four steps and the order of the calculated overall proton dissociation constants (${\log}{\beta}_p$) of each ligand was Br-BHE < Cl-BHE < H-BHE < Nap-BHE < $CH_3$-BHE < $CH_3O$-BHE. The order showed a similar trend to that of Hammett substituent constants(${\sigma}_P$). The order of the stability constants (${\log}K_{ML}$) was CO(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II). The order in their stability constants (${\log}K_{ML}$) of each transition metal complex agreed well with that of the overall proton dissociation constants (${\log}{\beta}_p$).

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.164-171
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• 2010

Recently, the waste of Polycarbonate(PC) is increase with the increase in demand of a polycarbonate. It is concerned with producing a new material and diol monomer, bishydroxyethyl ether of bisphenol A(BHE-BPA) through depolymerization of the polycarbonate waste at recycling. BHE-BPA can be used as a good raw material for the synthesis of polycarbonate type polyurethane. PC particles were depolymerized with base-catalyst NaOH, solvent EG, and ethylene carbonate(EC) was formed during the PC depolymerziation. EC was added to promote the conversion from bispenol-A to BHE-BPA. The characteristics of depolymeraion of polycarbonate as well as conversion of bispenol-A to BHE-BPA were investigated. BHE-BPA yield of 92% was obtained at temperature $220^{\circ}C$, 10% catalyst/PC mole ratio, 20 mmol of EC. BHE-BPA purity of better than 99% was achieved by crystallization of BHE-BPA.

• Journal of Nutrition and Health
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• v.30 no.4
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• pp.379-385
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• 1997

This study was designed to determine whether genetic defects in the efficiency of ATP synthesis existed in the NIDDM-prone BHE/cdb rat and to determine whether these defects caused the development of glucose intolerance. Thyroxine treatment provided an excellent clue as to the nature of the genetic defects in this rat. The characteristics of hyperhyroid and control Sprague-Dawley(SD) and BHE/cdb rats were studied. Hyperthyroidism was induced through the addition of thyroxine($T_4$) to the diet(2mg/kg of diet). Active proton conductances and passive proton conductances were tested. Mitochondria from hyperhyroid BHE/cdb rats were less efficient iii active proton conductances than mitochondria from hyperhyroid SD rats. It showed that decreased efficiency of ATP synthesis in the BHE/cdb rat was probably related to defects in active proton conductance, Indicating aberrant FoATPase. The levels of $F_1F_0$ATPaseATPase activity were tested. Mitochondria from hyperthyroid BHE/cdb rats were less active than mitochondria from hyperthyroid SD rats. This may be an attribute of aberrant F$_1$ATPase and may contribute to the BHE/cdb strain s characteristic of reduced ATP synthesis efficiency. Glucose tolerances were tested. BHE/cdb rats were profoundly affected by thyroxine, whereas SD rats were less so. It showed that the diabetes phenotype in BHE/cdb rats was related to defects in thyroxine-induced uncoupling. These results showed the decreased efficiency of ATP synthesis due to genetic defects in $F_1F_0$ATPase had relevance to the characteristic of impaired glucose tolerance in the NIDDM-prone BHE/cdb rat.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.581-586
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• 2009

Knowledge of ground thermal properties is most important for the proper design of large scale BHE(borehole heat exchanger) systems. The type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for insitu determination of design data for large diameter BHE for triple-U spacer apply. The main purpose has been to determine insitu values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a circulation pump, a inline heater, temperature sensors, flow meter, power analysis meter and a data logger for recording the temperature, fluid flow data. A constant heat power is injected into the borehole through the tripl-U pipes system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance of large diameter BHE for spacer apply.

• Journal of Soil and Groundwater Environment
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• v.21 no.3
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• pp.64-81
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• 2016

To analyze the influence of various groundwater flow rates (specific discharge) on BHE system with balanced and unbalanced energy loads under assuming same initial temperature (15℃) of ground and groundwater, numerical modeling using FEFLOW was used for this study. When groundwater flow is increased from 1 × 10⁻⁷ to 4 × 10⁻⁷m/s under balanced energy load, the performance of BHE system is improved about 26.7% in summer and 22.7% at winter time in a single BHE case as well as about 12.0~18.6% in summer and 7.6~8.7% in winter time depending on the number of boreholes in the grid, their array type, and bore hole separation in multiple BHE system case. In other words, the performance of BHE system is improved due to lower avT in summer and higher avT in winter time when groundwater flow becomes larger. On the contrary it is decreased owing to higher avT in summer and lower avT in winter time when the numbers of BHEs in an array are increased, Geothermal plume created at down-gradient area by groundwater flow is relatively small in balanced load condition while quite large in unbalanced load condition. Groundwater flow enhances in general the thermal efficiency by transferring heat away from the BHEs. Therefore it is highly required to obtain and to use adequate informations on hydrogeologic characterristics (K, S, hydraulic gradient, seasonal variation of groundwater temperature and water level) along with integrating groundwater flow and also hydrogeothermal properties (thermal conductivity, seasonal variation of ground temperatures etc.) of the relevant area for achieving the optimal design of BHE system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.3
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• pp.24-32
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• 2016

Commercial buildings and institutions are generally cooling-dominated and therefore reject more heat to a borehole ground heat exchanger (BHE) than they extract over the annual cycle. Shallow ponds can provide a cost-effective means to balance the thermal loads to the ground and to reduce the length of BHE. This paper presents the analysis results of the impact of design parameters on the length of SWHE pipe and its application effect on geothermal heat pump (GHP) system using BHE. In order to analysis, we applied ${\varepsilon}-NTU$ method on designing the length of SWHE pipe. Analysis results show that the required pipe length of SWHE was decreased with the increase of approach temperature difference and with the decrease of pipe wall thickness. In addition, when the SWHE was applied to the GHP system, the temperature of BHE was more stable than that of standalone BHE system.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.114-127
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• 2016

An increase of groundwater flux in BHE system creates that ground temperature (locT) becomes lower in summer and higher in winter time. In other words, it improves significantly the performance of BHE system. The size of thermal plume made up by advection driven-flow under the balanced energy load is relatively small in contrast to the unbalanced energy load where groundwater flow causes considerable change in the size of thermal plume as well ground temperature. The ground temperatures of the up gradient and down gradient BHEs under conduction only heat transport are same due to no groundwater flow. But a significant difference of the ground temperature is observed between the down gradient and up gradient BHE as a result of groundwater flow-driven thermal interference took placed in BHE field. As many BHEs are designed under the obscure assumption of negligible groundwater flow, failure to account for advection can cause inefficiencies in system design and operation. Therefore including groundwater flow in the design procedure is considered to be essential for thermal and economic sustain ability of the BHE system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.8 s.251
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• pp.764-771
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• 2006

Knowledge of ground thermal properties is most important for the proper design of large BHE(borehole heat exchanger) systems. Thermal response tests with mobile measurement devices were first introduced in Sweden and USA in 1995. Thermal response tests have so far been used primarily for in insitu determination of design data for BHE systems, but also for evaluation of grout material, heat exchanger types and ground water effects. The main purpose has been to determine insitu values of effective ground thermal conductivity, including the effect of ground-water flow and natural convection in the boreholes. Test rig is set up on a small trailer, and contains a circulation pump, a heater, temperature sensors and a data logger for recording the temperature data. A constant heat power is injected into the borehole through the pipe system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.829-837
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• 2000

Purpose : To investigate the inhibitory effect of BHE on platelet aggregation and erythrocyte deformability, we performed following experiments. Methods : Concentrated Boyanghwanotang (BHE) was fed to rats for 10days. High dose group was treated with $500{\beta}{\partial}/kg$ and low dose group with $500{\beta}{\partial}/kg$. Results : BHE enhanced the blood filtration rate, reduced the platelet aggregability, inhibited granule release from collagen-stimulated platelet, the prostaglandin syn-thesis in platelet and enhanced erythrocyte deformability. Conclusion : BHE should inhibit thrombos formation due to platlete hyperaggregabili-ty and reduction of erythrocyte deformabi-lity.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.477-480
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• 2007

Inlet fluid temperature of the BRE in the geothermal heat pump system depends on heat exchange rate between the refrigerant of the heat pump and the leaving fluid from the BRE. Because the outlet fluid temperature of the BHE varies with time, inlet fluid temperature has to vary with time. In this study, the module to calculate inlet fluid temperature is developed, which can consider the time-varying outlet fluid temperature and the heat exchange capacity of the heat pump. It is assumed that heat loss or gain of the leaving fluid from outlet to inlet of the BHE is negligible, except when the fluid contacts with the refrigerant of the heat pump. This module is combined with TOUGHREACT, a widely accepted three-dimensional numerical simulator for heat and water flow and geochemical reactions in geothermal systems and is applied to data analyses of the thermal response test.