• Korean Journal of Organic Agriculture
• /
• v.13 no.2
• /
• pp.129-143
• /
• 2005

Attempting to make an economic valuation of semi-liquid manure raises various complex questions. These are the valuation under different farming conditions, cost-benefit analysis in connection with the investment requirements of different semi-liquid manure systems, different storage capacities, transportation distances and treatment procedures. In the following, there questions will be discussed : 1. What value do the different types of semi-liquid manure have under different farming conditions? 2. Which storage capacities are economically justified? 3. Under which conditions is the transport of semi-liquid manure over long distances profitable?

• Journal of Korean Society on Water Environment
• /
• v.26 no.6
• /
• pp.1040-1048
• /
• 2010

An infiltration storage can be installed as a method of reducing runoff from catchment and increasing stream flow during the dry period by recharging groundwater. However, there is no proper model and method that can be used to design storage capacity of an infiltration storage in Korea. The purpose of the study is to evaluate capacities of infiltration storages planned on Jeju-do in Korea by modifying Storm Water Management Model (SWMM). The basic equations for the infiltration storage are same as those of the infiltration trench used in MIDUSS. Infiltration rates of the infiltration storages were first measured by double ring infiltrometers, and then the modified model was applied to evaluate adequacy for the capacities of three infiltration storages planned on Jeju-do in Korea. The application results show that the two infiltration storages with higher infiltration rates have adequate capacities to infiltrate the total water inflow to the storages. However, the other infiltration storage with lower infiltration rates has not sufficient capacity to infiltrate the total water inflow to the storage and release occurs to the downstream region. The simulation model and method applied can be used for capacity evaluation of future infiltration storages on highly pervious areas in Jeju-do.

• Journal of Hydrogen and New Energy
• /
• v.16 no.2
• /
• pp.122-129
• /
• 2005

The characteristics of hydrogen storage have been investigated in the Ti-Cr-Mo and Ti-Cr-V ternary alloys with bcc structure. The alloys were melted by arc furnace and remelted 4-5 times for homogeneity. The lattice parameters, microstructures and phases of the alloys were examined by SEM, EDX and XRD, and the Pressure-Composition isotherms of the alloys were measured. From these data the relationship of the maximum and effective hydrogen storage capacities vs. chemical composition, lattice parameter and the radius of tetrahedral site were analyzed and discussed. The results showed that all of these alloy, in the range of the this study, had mainly bcc solid solutions with small amount of Ti segregation due to a lower melting point of Ti compared with other elements. Lattice parameters of the alloys were very near to the atomic average values of lattice parameters of the constituent elements. It was also found that maximum hydrogen storage capacities of the Ti-Cr-Mo alloys increased with increasing Ti content and the radius of tetrahedral site but the effective hydrogen storage capacities decreased after showing the maximum. The hydrogen storage capacities of the Ti-Cr-V alloys were almost same even though the V contens were quite different from alloy to alloy and this could be attributed to the almost same Ti/Cr ratio of the alloys. The maximum effective hydrogen storage capacity of the Ti-Cr-Mo alloys was revealed at Ti content of about 40${\sim}$50 at% and radius of tetrahedral site of 0.43${\sim}$0.45 nm. The Ti-Cr-V alloys showed the hydrogen storage capacities of 3.0 wt% and effective hydrogen storage capacities of 1.5 wt%.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.31 no.3
• /
• pp.11-25
• /
• 2006

Space may be a scarce resource in manufacturing shops, warehouses, freight terminals, and container terminals. This Paper discusses how to locate temporary storage Inventories In limited storage areas. A typical inventory is delivered from the location of the preceding process to the storage area and stored In the storage area during the certain period of time. And it may be relocated from the storage position to another. Finally. it is delivered from the final storage area to the location of the next process. Because this logistic process for an inventory requires handling activities, transportation activities, and storage spaces, the limitation in capacities of handling equipment, transportation equipment, and storage space must be considered when allocating spaces to the inventory. This problem Is modeled as a multicommodity minimal cost flow problem. And a heuristic algorithm for the Problem is proposed. Numerical experiments are presented to validate the mathematical model and the heuristic algorithm.

• Journal of Hydrogen and New Energy
• /
• v.8 no.1
• /
• pp.31-41
• /
• 1997

In order to investigate the mechanism of electrochemical hydrogenation reaction on Zr-based Laves phase hydrogen storage alloy electrodes, electrochemical charge/discharge characteristics, potentiostatic/dynamic polarizations and electrocehmical impedance spectroscopy(EIS) of Zr-Ti-Mn-Ni and Zr-Ti-Mn-Ni-M(M=Fe, Co, Al) alloys were examined. Electrochemical discharge capacities of the alloys were quite different with gas charge capacities. Therefore, it was considered that discharge capacities of the alloys depend on electrochemical kinetic factors rather then thermodynamic ones. Discharge efficiencies were increased linearly with exchange current densities. The results of potentiostatic/dynamic polarization measurements showed that electrochemical charge and discharge reaction of Zr-based Laves phase hydrogen storage alloys is controlled by charge transfer process at the electrode surface. The EIS measurements also confirmed this result.

• Macromolecular Research
• /
• v.13 no.6
• /
• pp.521-528
• /
• 2005

Electrospun polyacrylonitrile (PAN) nanofibers were carbonized with or without iron (III) acetylacetonate to induce catalytic graphitization within the range of 900-1,500$^{circ}C$, resulting in ultrafine carbon fibers with a diameter of about 90-300 nm. Their structural properties and morphologies were investigated. The carbon nanofibers (CNF) prepared without a catalyst showed amorphous structures and very low surface areas of 22-31 $m^{2}$/g. The carbonization in the presence of the catalyst produced graphite nanofibers (GNF). The hydrogen storage capacities of these CNF and GNF materials were evaluated through the gravimetric method using magnetic suspension balance (MSB) at room temperature and 100 bar. The CNFs showed hydrogen storage capacities which increased in the range of 0.16-0.50 wt$\%$ with increasing carbonization temperature. The hydrogen storage capacities of the GNFs with low surface areas of 60-253 $m^{2}$/g were 0.14-1.01 wt$\%$. Micropore and mesopore, as calculated using the nitrogen gas adsorption-desorption isotherms, were not the effective pore for hydrogen storage.

• Journal of Industrial Technology
• /
• v.20 no.A
• /
• pp.131-138
• /
• 2000

A past monthly data is not faithful so much for a short term. But, the stochastic generation technique was provide of a long-term data. Thus this study is used a data which generated a monthly inflow amounts data by Thomas-Fiering model. This model is needed a certain process which determination of distribution, decision of continuous durability, etc. It was generated a inflow data every one month as Thomas-Fiering method. The generated inflow data was used input data for a monthly cumulative analysis. This analysis obtained a storage capacities which would be required during droughts having various return periods. It was presented a equation of fitting regression that was carried out regression analysis of 5, 10, 20, 50 years period.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.157.2-157.2
• /
• 2011

In this work, we prepared Mg nanoparticles loaded graphite oxide (Mg-G) as a function of Mg content in order to investigate hydrogen storage behaviors. The structure and morphology of the Mg-G samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The textural properties of the samples were evaluated using $N_2$/77 K adsorption isotherms. The hydrogen adsorption capacities were investigated at 298 K/10 MPa. As a result, the hydrogen adsorption capacities of the Mg-G were enhanced with increasing the Mg content. Therefore, it was found that the presence of Mg on graphite surfaces created hydrogen-favorable sites, resulting in enhancing the hydrogen adsorption capacity.

• Preventive Nutrition and Food Science
• /
• v.20 no.3
• /
• pp.169-175
• /
• 2015

Shinseoncho and kale were made into green vegetable juices by building block [shinsenocho branch (SB), shinsenocho leaf (SL), kale branch (KB), and kale leaf (KL)]. Fluctuations in their phenolic contents and antioxidant capacities were analyzed during refrigerated storage at $4^{\circ}C$ for 28 days. Total polyphenolic contents of leaf parts showed a decreasing tendency after 4 days (SL) or 7 days (KL), whereas branch parts showed fluctuating values during the entire storage period. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity was rapidly decreased in SB and in SL at 28 days (P<0.001), whereas KL showed a slightly increasing tendency after 14 days. For the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, SL showed a sharp fall at 28 days (P<0.001), and KL showed a decreasing tendency after 14 days (P<0.001). SB showed a steady decrease during the entire storage period and KB indicated a nearly zero (0.97%) at 28 days. Pearson's coefficients for the correlation between antioxidant capacities measured by the ABTS and DPPH assays, and the total polyphenolic contents were determined. The results showed that the ABTS assay (r=0.934, P<0.001) was more strongly positively correlated with the total phenolic contents than the DPPH assay (r=0.630, P<0.001). In conclusion, when considering all building blocks, green vegetable juices, including kale and shinseoncho may have kept antioxidant capacities for up to 14 days under refrigeration, and the ABTS assay better reflects a positive correlation with the total phenolic contents when compared to the DPPH assay.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.11
• /
• pp.592-604
• /
• 2017

A chiller, having a thermal storage system, can contribute to load-leveling and can reduce the cost of electricity by using electricity at night. In this study, the control experiments and simulations are conducted using both conventional and advanced methods for the building cooling system. Advanced approaches, such as the "region control method", divide the control region into five zones according to the size of the building load, and determines the cooling capacities of the chiller and thermal storage. On the other hand, the "dynamic programming method" obtains the optimal cooling capacities of the chiller and thermal storage by selecting the minimum-cost path by carrying out repetitive calculations. The "thermal storage priority method" shows an inferior chiller performance owing to the low-part load operation, whereas the chiller priority method leads to a high electric cost owing to the low utilization of thermal storage and electricity at night. It has been proven that the advanced control methods have advantages over the conventional methods in terms of electricity consumption, as well as cost-effectiveness. According to the simulation results during the winter season, the electric cost when using the dynamic programming method was 6.5% and 8.9% lower than that of the chiller priority and the thermal storage priority methods, respectively. It is therefore concluded that the cost of electricity utilizing the region control method is comparable to that of the dynamic programming method.