• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.243-252
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• 2013

This study was carried out to investigate safety evaluation of agricultural reservoirs due to raising the embankment. The seepage analysis and large-scale model test were performed to compare and analyze the pore water pressure(PWP), leakage quantity, settlement and piping phenomenon in the inclined core type and the vertical core type embankments. The PWP after raising the embankment showed smaller than before raising the embankment and the stability for piping after raising the embankment. The allowable seepage quantity and the allowable leakage for the steady state and transient conditions is within the range of safe management standard. After raising the embankment in the inclined core, there was no infiltration by leakage. For the vertical core, the PWP showed a large change by faster infiltration of pore water than in the inclined core. In a rapid drawdown, inclined core was remained stable but the vertical core showed a large change in PWP. Settlement after raising the embankment showed larger amounts of settlement than before raising the embankment. The leakage quantity before raising the embankment and the inclined core type showed no leakage. From the result, an instrument system that can accurately estimate a change of PWP shall be established for the rational maintenance and stabilization of raising the embankment for agricultural reservoirs.

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.493-504
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• 2011

This study was carried out to safety evaluation, the practical application and improvement of design method of the agricultural reservoir due to raising embankments. Also, it was to compare and analyze the pore water pressure (PWP), seepage (leakage) quantity and piping phenomenon according to high water table and rapid drawdown. The seepage analysis by finite element analysis was used for steady state and transient condition. The pore water pressure distribution for steady state and transient condition showed positive(+) PWP on the upstream slope, it was gradually changed negative(-) PWP on the downstream slope. The PWP in the core ranged from 100 ~ -33 kPa, the seepage line in the incline-type core suddenly decreased towards the lower levels from the higher levels. The PWP according to rapid drawdown is remained in the vicinity of the upstream slope, therefore, it is investigated to be in an unstable state by the slope stability analysis. The PWP after raising embankments showed smaller than in the before raising embankments. It was likely to be the piping phenomenon because the gradients in the before raising embankments showed largely at downstream slope, and the stability for piping in the after raising embankments increased stable state. The seepage quantity per 1 day and the leakage per 100m for the steady state and transient condition appeared to be safe against the piping. It reduced slightly regardless of the transient condition before the raising embankments and it decreased largely about 2.4 times in the early days after the raising embankments.

• Culinary science and hospitality research
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• v.23 no.5
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• pp.25-33
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• 2017

This study was to investigate the effects of enzyme on quality characteristics and antioxidant activities of wild peach (Prunus persica L.) juice. pH levels and S.S (soluble solid) values in all samples ranged from 3.86 to 4.13 and from 48.0 to $55.0^{\circ}Brix$, respectively. The TA (total acidity) values of control (not treatment enzyme) were higher than those of the others. The highest 'L', 'a' and 'b' values were observed on PWP (preserved wild peach (Prunus persica L.) juice of cellulase/pectinase (1:1, w/w) sample. Glucose (26.65 g/100 g) and fructose (17.42 g/100 g) in PWP product were determined, however sucrose and maltose were not detected. The predominating organic acid components analyzed in PWP sample were tartaric (32.36 g/100 g) and lactc acids (209.34 g/100 g), whereas citric acid, acetic acid and malic acid were not detected. Higher scores for taste, flavor, color and overall acceptance were found for PWP products compared to other samples. The total phenolic content (13.31 mg GAE/mg dry weight) analyzed using Folin-Ciocalteu's reagent, of PWP sample was higher than those of the others and the total flavonoid concentrations were also 10.95 mg CE/mg dry weight. The DPPH radical scavenging and ABTS radical scavenging activities in all samples ranged from 55.16 to 74.29% and from 39.59 to 82.79%, respectively. The antioxidant activities were affected by addition of enzyme. These results indicate that the use of the mixture of cellulase and pectinase could increase the quality, and antioxidant potentials of sugar preserved wild peach (Prunus persica L.) juice by enzymatic treatment.

• Geomechanics and Engineering
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• v.35 no.4
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• pp.449-464
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• 2023

Advanced nonlinear effective stress constitutive models are started to be frequently used in one-dimensional (1D) and two-dimensional (2D) site response analysis for assessment of porewater generation and liquefaction potential in soft soil deposits. The emphasis of this research is on the assessment of the implementation of this category of models at the element stage. Initially, the performance of a coupled porewater pressure (PWP) and constitutive models were evaluated employing a catalogue of 40 unidirectional cyclic simple shear tests with a variety of relative densities between 35% and 80% and effective vertical stresses between 40 and 80 kPa. The authors evaluated three coupled constitutive models (PDMY02, PM4SAND and PDMY03) using cyclic direct simple shear tests and for decide input parameters used in the model, procedures are recommended. The ability of the coupled model to capture dilation as strength is valuable because the studied models reasonably capture the cyclic performance noted in the experiments and should be utilized to conduct effective stress-based 1D and 2D site response analysis. Sandy soils may become softer and liquefy during earthquakes as a result of pore-water pressure (PWP) development, which may have an impact on seismic design and site response. The tested constitutive models are mathematically coupled with a cyclic strain-based PWP generation model and can capture small-strain stiffness and large-strain shear strength. Results show that there are minor discrepancies between measured and computed excess PWP ratios, indicating that the tested constitutive models provide reasonable estimations of PWP increase during cyclic shear (r_u) and the banana shape is reproduced in a proper way indicating that dilation and shear- strain behavior is well captured by the models.

• Nuclear industry
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• v.7 no.1 s.47
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• pp.116-121
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• 1987

90년대 원자력의 주문이 재개될 것으로 기대하여 원자력산업계에서는 보다 개량되고 보다 간단하고 보다 염가한 PWP와 BWR설비의 관발를 서두르고 있으며 획기적이고 새로운 개념이 21세기를 향하여 연구개발될 것이다.

• Nuclear industry
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• v.7 no.4 s.50
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• pp.80-81
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• 1987

Baffle Jetting에 의해 발생하는 PWP연료봉의 손상을 방지하기 위해 몇 개의 연료봉을 Clip사용으로 함께 묶음으로써 적은 비용으로 간단하게 방지할 수 있으며 이 방법을 사용해 본 결과 좋은 성과를 얻었다.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.385-392
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• 2018

Poly vinyl chloride (PVC) was chemically modified, and used for ultrafiltration to analyze the performance. Non-solvent induced phase separation (NIPS) method was used to prepare membranes. The neat PVC membrane was casted and used as a control membrane. Modified membrane was prepared by reacting PVC with ethanolamine (EA) in the casting solution (labeled as CM-PVC). Pure water permeability (PWP) was evaluated by measuring pure water flux. Humic acid was used as model foulant solute to analyze flux and rejection ability of membranes. Flux and rejection data of neat and modified membranes were compared to prove the improvement in the filtration performance. The experimental results showed that for PVC and CM-PVC, PWP was calculated to be ~64 and ${\sim}143L/m^2{\cdot}h$, respectively, and the rejection of humic acid was found to be 98% and 100%, respectively. TGA was carried out to analyze the effect of chemical modification on the thermal stability of polymer. FT-IR analysis was another characterization technique used for the comparative study.

• Environmental Engineering Research
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• v.19 no.4
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• pp.339-344
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• 2014

Different types of polyethersulfone (PES) support layer for a thin film composite (TFC) membrane were synthesized under various synthesis conditions using the phase inversion method to study the combined effects of substrate, adhesive, and pore former. The permeability, selectivity, pore structure, and morphology of the prepared membranes were analyzed to evaluate the membrane performance. The combined use of substrate, adhesive, and pore former produced a thinner dense top layer, with more straight finger-like pores. The pure water permeation (PWP) of the optimized PES membrane was $27.42L/m^2hr$ (LMH), whereas that of bare PES membrane was 3.24 LMH. Moreover, membrane selectivity, represented as divalent ion ($CaSO_4$) rejection, was not sacrificed under the synthesis conditions, which produced the dramatically enhanced PWP. The high permeability and selectivity of the PES membrane produced under the optimized synthesis conditions suggest that it can be utilized as a potential support layer for TFC membranes.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.83-92
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• 2008

In order to analyze infiltration characteristics of rainfall in soil, two laboratory experiments were conducted using an amplitude domain reflectometry (ADR) sensor and a pore water pressure meter (PWP) in this study. The first experiment is to understand the dependency of volumetric water content and temperature for standard sand and weathered granite soil. The second experiment is a laboratory flume test with changes of rainfall condition. As the results of the dependency experiment, the volumetric water content is increased with increase of the output voltage measured by the ADR sensor in both the standard sands and weathered granite soil. Furthermore, the results also indicate necessity of consideration of the temperature dependency under the condition of high volumetric water contents from 0.15 to 0.45. In the flume test, two measurement devices are detected to the variation of volumetric water content and pore water pressure at the installation point of the flume. In especial, the measured values of ADR4 and PWP3 installed on the lower part of slope are higher than those of the others. It means that the lower part of slope plays a role of a runoff face and a beginning point of slope failure.

• Phonetics and Speech Sciences
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• v.11 no.3
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• pp.57-67
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• 2019

This study aimed to investigate regional differences in the development of speech production in Korean children. A total of 619 children aged 2 to 7 years from the Jeolla, Seoul/Gyeonggi, Chungcheong, and Gyeongsang areas were included in this study. The subjects were assessed with the UTAP2 word-level test. In PWC, PMLU, and PWP, the performance was significantly lower in Gyeongsang at 2 years 11 months and in Jeolla and Chungcheong at 3 years 5 months than in Seoul/Gyeonggi. The total PCC of Gyeongsang and Chungcheong and UTAP PCC of Chungcheong were significantly lower at 2 years 11 months compared with those of Seoul/Gyeonggi, while Jeolla and Chungcheong showed significantly lower total PCC and UTAP PCC than Seoul/Gyeonggi at 3 years 5 months. However, no regional difference was observed in any indicators after the age of 3 years 6 months. These results suggest that there are regional differences in the ability to produce speech sounds at a very young age, and that the differences can be explained by the differences between Seoul/Gyeonggi and the other provinces rather than by the individual characteristics of specific regions.