• The Journal of Korean Physical Therapy
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• 제26권6호
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• pp.425-429
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• 2014

Purpose: The first purpose of this study was to evaluate whether hand muscle fatigue alters sensorimotor control of the hand in healthy subjects, using hand position sense. The second objective was to assess the repositioning variables during a 7.5-min period after the fatigue protocol. Methods: Participants performed a repeated handgrip movement to induce the fatigue condition as fast as possible, until they could no longer continue. Recordings were performed before (pre-fatigue) and after the completion of the fatigue exercises (immediately: post-fatigue, after a 2.5 min recovery, after a 5 min recovery and after a 7.5 min recovery). Results: The joint reposition test of the MP joint in the post-fatigue condition showed higher reposition errors than the prefatigue condition (p<0.05). Additionally, there was a significant difference in recovery of joint reposition errors after fatiguing exercises of the hand muscle, among groups (p<0.05). Conclusion: The fatigue of the hand muscles affected joint position sense by an alteration of somatosensory and proprioceptive information. Nonetheless, the effect of hand muscle fatigue was short-lived, since joint reposition errors decreased to post-fatigue values after 7.5 min of recovery.

• Membrane and Water Treatment
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• 제12권1호
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• pp.1-9
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• 2021

This study optimized the chemical cleaning process of discarded RO membranes for reuse in less demanding separation processes. The effect of physicochemical parameters, including the temperature, cleaning time, pH of the cleaning solution, and addition of additives, on the cleaning process was investigated. The membrane performance was evaluated by testing the flux recovery rate and salt rejection before and after the cleaning process. High temperatures (45-50 ℃) resulted in a better flux recovery rate of 71% with more than 80% salt rejection. Equal time for acid and base cleaning 3-3 h presented a 72.43% flux recovery rate with salt rejection above 85%. During acid and base cleaning, the best results were achieved at pH values of 3.0 and 12.0, respectively. Moreover, 0.05% concentration of ethylenediaminetetraacetic acid presented 72.3% flux recovery, while 69.2% flux was achieved using sodium dodecyl sulfate with a concentration of 0.5%; both showed >80% salt rejection, indicating no damage to the active layer of the membrane. Conversely, 0.5% concentration of sodium percarbonate showed 83.1% flux recovery and 0.005% concentration of sodium hypochlorite presented 85.2% flux recovery, while a high concentration of these chemicals resulted in oxidation of the membrane that caused a reduction in salt rejection.

• 한국산업보건학회지
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• 제30권4호
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• pp.387-393
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• 2020

Objective: This study aimed to investigate the differences in temporary threshold shift (TTS) and recovery patterns according to different types of sound and volume. Methods: TTS and recovery patterns were assessed for eight students after 30-minute exposure to both 70.0 dB and 90.0 dB of factory noise (noise) as well as music. TTS was measured before exposure and two minutes post exposure, and recovery patterns were evaluated every 10 minutes for one hour. The subjects performed activities of daily life and sleeping times as usual but taking drugs or drinking alcohol were prohibited. The experiment was repeated three times with an interval of at least 16 hours. ANOVA and T-test were carried out using SPSS 19.0 for Windows. Results: The hearing threshold of all subjects before exposure was less than 30 dB at all frequencies. Mean TTSs of 70 dB noise and 90 dB noise exposure were 0.14 and 4.48 dB (p<0.001). Meanwhile, the difference in music was insignificant (-0.63 dB and 0.55 dB, p=0.063). A significance in the difference was also found between the mean TTS of music and noise exposure, more obviously at 90.0 dB (p<0.001) than at 70 dB (p=0.232). The TTS differences were found frequency-wise in terms of sound type. Mean TTS by frequency was higher at 4,000 and 6,000 Hz than at other frequencies, and higher in noise than music at the same sound pressure. The TTS difference in each frequency between both sound types was significant at 90 dB (p<0.001). Subjects mostly recovered from TTS in one hour after exposure, but not with 90 dB-noise exposure. Conclusion: TTS and recovery patterns were different depending on the sound type. When exposed to factory noise, TTS was greater and recovery time was longer compared to music at the same sound pressure. These results suggested that the difference in cognitive processes and psychological factors according to the type of sound causes a change in TTS and recovery.

• Journal of Chest Surgery
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• 제25권11호
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• pp.1203-1208
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• 1992

Current methods of myocardial protection has been improved with cardioplegia and hypothermia. We compared St. Thomas hospital cardiopleic solution without oxygenation[Group I], with oxygenation[Group II] and with oxygenation with filter[Group III] under isolated working heart model. Heart rate recovery was more significantly improved in Group II than Group I after 15 minutes of recovery time [p<0.05]. Maximal systolic pressure shows no difference as it increases with time. Cardiac ouputs were not diffrent between groups. Recovery time was shorter significantly in group II and group III than group I [p<0.05] Use of filter showed no difference. As a conclusion, oxygenated cardioplegic solutions improves ability to protect the heart against ischemia and it is manifested by improved recovery time and heart rate.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.43-44
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• 2002

Basically all cells have the recovery mechanisms from the shift of intracellular pH (pHi). Many mechanisms were found and characterized. Generally the recovery mechanisms from acidosis are Na$\^$＋/-dependent, such as Na$\^$＋/-H$\^$＋/ exchange and Na$\^$＋/-HCO$_3$-symport. The recovery mechanism from alkalosis are Cl-dependent, such as Cl$\^$-/-HCO$_3$-exchange and Cal$\^$-/-OH$\^$-/ exchange.(omitted)

• Journal of Biosystems Engineering
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• 제31권1호
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• pp.46-51
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• 2006

This study was carried out to recover phosphorus in animal wastewater using a magnesium source. $MgCl_2$, as a magnesium source, was shown a SP (soluble phosphorus) recovery rate of 98% in both the aeration and the NaOH tests to adjust pH around 8.5. In case of MgO, the recovery rate of SP were 88% with the aeration and 58% with the NaOH. In case of ammonia nitrogen recovery, $MgCl_2$ was shown the recovery rate of 17% with aeration and 18% with NaOH. MgO was shown the ammonia recovery rate of 18% with aeration and 11% with NaOH. At low temperature of $6-8^{\circ}C$ with the animal wastewater from piglet stall, the recovery rate of SP was shown 95% with NaOH and 92% with aeration using $MgCl_2$. The recovery rate of ammonia nitrogen was shown 9% with NaOH and 12% with aeration, respectively. It was observed that the pH can be raised by aeration. The reaction was completed within 5 minutes and the struvite cristal structure was formed and could be observed with an electronic microscope.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.829-834
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• 2002

Carbonation of concrete used impregnation alkalization agent construction reinforcement, recovery of pH, elevation improve, in which efficiency decline mternal force of number and durability because of impregnation alkalization agent applyment general standard, used concrete. Material quality not understanding lack of study and stadard. This study investigate change of PH. recovery depth of impregnation alkalization agent, recovery depth belong a mount of aggregate that comparision, analysis parity.

• 한국식품저장유통학회지
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• 제22권2호
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• pp.256-260
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• 2015

본 연구에서는 알칼리 사용에 따른 갈변을 최소화하고 영양적으로 우수한 천마 단백질을 보다 효율적으로 추출하기 위하여 용출 및 침전 pH에 따른 단백질의 갈변도와 함량을 측정함으로써 탈지 천마 단백질 알칼리 추출의 최적 pH 조건을 설정하고자 하였다. 천마의 수분은 약 15%로 측정되었으며, 대부분 탄수화물로 구성되어 있었고, 단백질의 함량이 높은 것으로 확인되었다. 이러한 단백질을 다양한 pH에서 용출시킨 결과 pH가 증가함에 따라 용출된 단백질의 양이 증가하였으며, 갈변도 또한 증가함을 보였다. 침전 pH에 따른 단백질 함량은 pH 4에서 침전된 pellet이 가장 많은 함량을 나타내었으며, 상등액의 단백질 함량 또한 대부분 pH 4로 침전시킨 경우 가장 적은 것으로 확인되었다. 뿐만 아니라 단백질의 회수율도 침전 pH가 4일 때 가장 높은 값을 나타내었다. 따라서 갈변도와 단백질 함량을 고려한 탈지 천마 단백질 추출을 위한 최적조건은 용출 pH 9와 침전 pH 4로 결정되었다.

• 한국수정란이식학회지
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• 제11권3호
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• pp.309-316
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• 1996

The aim of this study is to elucidate sperm chemotaxis and to set up the optirnal condition for selection of motile and capacitated sperm from hovine frozen-semen. Thus, the effects of semen-washing after thawing, concentrations of progesterone (P4) and bovine serum albumin (BSA), and sperm-washing frequency on sperm selection were examined. For evaluating their effects, number, viability and acrosome reaction of sperm swim-up seperated from semen, which were incubated for 30 minutes at 36$^{\circ}C$ in the M2 solution containing P4 and BSA, were investigated. For frozen-semen just after thawing, sperm recovery and viability were not significantly different between P4-treated and -untreated semen. However, washing frozen-semen decreased the number of sperm and increased the viability of sperm that were recovered from semen treated with P4. Progesterone affected the recovery rate, the viability and the acrosome-reaction rate of sperm recovered from washed frozen-semen. Especially, number of motile and capacitated sperm were highest in semen treated with 50$\mu$g /ml among 0, 20, 50 and 100$\mu$g /ml of P4 concentrations. BSA affected the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4. Especially, the percentage of viable sperm were highest in semen treated with 4mg /ml among 0, 2, 4, and 6mg /ml of BSA concentrations. Repeatedly sperm-washing did not affect the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4 and 4mg /ml of BSA In conclusion, using progesterone and BSA could efficiently make the selection of motile and capacitated sperm from washed frozen-semen.

• 대한토목학회논문집
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• 제26권4A호
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• pp.677-687
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• 2006

크리깅 보간법은 지구통계학 분야에 주로 사용되는 보간법의 하나이다. 이 방법은 실험적 베리오그램과 이론적 베리오그램의 작성과 크리깅 보간법의 정식화에 관한 연구를 포함하고 있다. 종래의 응력복구를 위한 최소제곱법과 대조적으로, 가우스적분점에서의 응력데이타로부터 준정해를 얻기 위해 가중 최소제곱법에 기초를 둔다. 즉, 동일한 가중치를 사용하는 종래의 방식들과는 달리 가우스적분점에서의 응력값의 보간을 위하여 베리오그램 모델링을 통한 가중치가 결정된다. 한편, 분할된 요소망에 Zienkiewicz와 Zhu에 의해 제안된 SPR기법에 기초를 둔 사후오차평가를 통해 p-차수를 균등 또는 선택적으로 증가시키는 자동체눈 방식이 도입되었다. 이 방법의 정당성을 보기위해 인장력을 받는 개구부를 갖는 평판문제를 해석하였다. 또한, 기존의 최소제곱법과의 비교를 통한 크리깅보간법의 정당성을 보여 주었다.