• Title/Summary/Keyword: MH

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Influences of Various Electrolytes on the Low-Temperature Characteristics of Ni-MH Secondary Battery (Ni-MH 2차 전지의 저온특성에 미치는 전해액의 영향)

  • Park, Chae-Gyu;Shim, Jong-Su;Jang, Min-Ho;Park, Choong-Nyeon;Choi, Jeon
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.3
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    • pp.284-291
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    • 2007
  • The Ni-MH batteries for HEV and industry are normally placed in outdoor, consequently causing an too weak discharge power problem due to a cold weather specially in winter time. In order to improve the low temperature performances of the Ni-MH battery for HEV and industrial uses, it has been investigated the low temperature discharge characteristics of Ni-MH battery with various electrolytes at $-18^{\circ}C$. The summary of experimental results are as follows. The low temperature characteristics depended strongly on the characteristics of electrolytes. When the concentration of the electrolytes were too high or too low the low temperature performance was poor. The best electrolyte was composed of KOH 6.2M+LiOH 1.2M. An addition of RbOH or CsOH to electrolyte improved the low temperature performance. The best total concentration of electrolyte composed of KOH, NaOH and LiOH was about 7M.

Studies on Anti-inflammatory Effects of Mahwanghangingamchosukgo-tang Extracts (마황행인감초석고탕 추출물의 항염증 효과에 대한 연구)

  • Park, Jung Eun;Hwang, Hyung Seo;Kim, Tae Yeon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.6
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    • pp.319-325
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    • 2020
  • Mahwanghangingamchosukgo-tang (MH) is recorded as a treatment to treat exterior-related respiratory diseases in the Korean medicine. In this study, we examined the anti-inflammatory effects of MH, using MH water extract and lipopolysaccharide (LPS)-induced RAW 264.7 cells. First of all, we measured the amount of nitric oxide (NO) and prostaglandin E2 (PGE2), the products of inflammatory metabolism. Also, we measured enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as well as cytokines such as interleukin 6 (IL-6), interleukin 1 alpha (IL-1α), and interleukin 1 beta (IL-1β). MH suppressed the production of NO and PGE2 in a dose dependent manner and reduced the amount of protein and the mRNA expression of iNOS and COX-2. Also, MH reduced the mRNA expression of IL-6, IL-1α and IL-1β. In conclusion, MH decreased production of LPS-induced inflammatory factor, which could be a clinical basic subject for inflammatory diseases.

Body mass index and massive hemorrhage after cesarean section in patients with placenta previa

  • Changrock Na;Hyun Jung Kim
    • Journal of Medicine and Life Science
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    • v.19 no.2
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    • pp.39-45
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    • 2022
  • This study was undertaken to assess the potential of body mass index (BMI) as a risk factor for massive hemorrhage (MH) after cesarean section (CS) in patients with placenta previa. We retrospectively reviewed the medical records of patients who underwent CS for placenta previa between January 2010 and December 2018. MH was defined as an estimated blood loss ≥2,000 mL during surgery. Clinical characteristics, including BMI, were compared between the groups with and without MH. Subsequently, multivariable logistic regression analysis was conducted to identify the independent risk factors for MH. A total of 189 patients were included in this study. MH was observed in 28 patients (14.8%). According to the multivariable logistic regression analysis results, the risk factors independently associated with MH were BMI at delivery (adjusted odds ratio [aOR], 1.19; 95% confidence interval [CI], 1.04-1.35; P=0.012), placenta accrete (aOR, 24.55; 95% CI, 2.75-219.02; P=0.004), and total previa degree (aOR, 9.86; 95% CI, 2.71-35.96; P=0.001). The study findings showed that maternal obesity, namely a higher BMI at delivery, was an independent risk factor for MH after CS in patients with placenta previa. Close attention should be paid to the potential risk of hemorrhage associated with maternal obesity as well as the well-known risk factors of placenta accreta and total previa degree.

Preparation and Characteristics of Bread by Medicinal Herb Composites with Cognitive Function (인지기능활성을 가진 생약복합물을 이용한 빵의 제조 및 특성)

  • Kang, Jin-Soon;Kang, Shin-Kwon;Kim, Hee-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.9
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    • pp.1131-1138
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    • 2009
  • In this study, the breads with medicinal herbs (MH) composites showing cognitive function were prepared and their characteristics were examined. Fifteen kinds of medicinal herbs were extracted with hot water and divided into 3 groups (MH-1, MH-2, MH-3) based on their contents. All groups showed cognitive function in terms of promoting muscarinic receptor, NMDA receptor and acetylcholinesterase inhibition. In the preparation of breads containing MH extracts of various contents (0, 10, 20, 30, and 50%), there were no significant difference among loaf weight of all groups, but loaf volume of all groups were significantly (p<0.05) decreased with increasing content of MH extracts compared to the control group. The "a" and "b" values of bread crumb increased with the content of MH extracts while "L" value decreased, but these values of bread crust were similar to the control group. The most improvements in hardness, fracturability, cohesiveness, gumminess and chewiness of bread were noticed by the addition of 10$\sim$20% MH extracts, while adhesiveness and springiness of bread were the most by the 30% addition ones. Through the sensory evaluation, it was revealed that appearance, mouth feeling, taste, overall preference and crumb texture of bread were not significantly different (p<0.05) between control and those with the 10% addition ones. Therefore the 10% addition ones, which got similar scores to control, will make the most desirable product.

Effect of Chemicals on Inducing Grain Sterility of Rice (수도의 불임 유기를 위한 몇가지 화학제의 효과)

  • Song, Moon-Tae;Kim, Jeung-Kyo;Choe, Zhin-Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.4
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    • pp.309-314
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    • 1990
  • A pot experiment was carried out to find the effects of chemicals and its application time on the sterility and other agronomic characters of rice. Two rice cultivars, Samgangbyeo, a Tongil type, and Chuchungbyeo, a japonica type rice were treated with maleic hydrazide (6000ppm), ethephon (6000ppm) and GA3 (10ppm) at five different growth stages. The application times of chemicals were comprised of two different stages of stem elongation and booting and panicle emerging stage. Grain sterility and panicle length were measured for panicles per pot. Culm length was measured for pot basis. MH induced complete grain sterility in rice, but caused severe plant damage (phytotoxicity) ; restricted spike emergence and drying out of plant leaves, sheath and panicles. Ethephon induced 50-60% grain sterility in rice with the least in plant damage. GA3 was not effective in inducing grain sterility in rice, but it increased culm length. The earlier application of chemicals, the higher sterility was induced. Both MH and ethephon reduced culm length and grain yield. Also observed was the varietal response in the occurrence of to chemicals Samgangbyeo showed the higher response to chemicals than Chuchungbyeo.

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Fishing efficiency of LED fishing lamp for squid jigging vessels (오징어 채낚기어선용 LED 집어등의 어획성능)

  • An, Young-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.385-394
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    • 2013
  • This study has conducted a comparative analysis on the fishing efficiency of LED fishing lamps by squid jigging vessels, the Yeongrak-ho (16 tons) and Somang-ho (9.77 tons), which operated during September and October 2010 and during October 2011, comparing with MH (Metal Halide) fishing lamp-equipped fishing vessels. This study has also examined vessel's fuel consumption level. The light powers of LED fishing lamps of the Yeongrak-ho and Somang-ho were 25.8kW and 32kW, respectively. Those of the MH fishing vessels, that is, the MH fishing lamp-equipped fishing vessels, were 105kW and 81kW, respectively. The average squid catch in number of an LED vessel, Yeongrak-ho, was 39.2% of the MH fishing lamp-equipped fishing vessels; however, that of the Somang-ho improved to 78.7% of the MH fishing lamp-equipped vessels. Average catch in number by Yeongrak-ho crew was 2.6 times more than catch in number by automatic jigging machines. Average catch in number by MH fishing vessel crew was 1.8 times more than that by automatic jigging machines. An LED vessel, Yeongrak-ho's fishing rate was 17.5%~152.2% of the MH fishing vessels, that is, 61.1% on average, in comparison of combined catch in number per automatic jigging machine and per crewmember. Somang-ho's fishing rate was 6.7%~127.6% of the MH fishing vessels, that is, 73.1% on average. The average fuel consumption level of the Somang-ho, throughout its departure from to arrival at the port, was 475.7l, and that during fishing hours was 109.6l, or 23.0% of the total fuel consumption level. Somang-ho's fuel consumption level per fishing hour was 9.7l on average.

Coupled Motion Simulation of the Mobile Harbor and Anti-Rolling Devices in Waves

  • Yoon, Hyeon-Kyu;Kang, Joo-Nyun;Lew, Jae-Moon;Moon, Seok-Joon;Chung, Tae-Young
    • Journal of Navigation and Port Research
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    • v.34 no.4
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    • pp.271-279
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    • 2010
  • The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

A study on the characteristics of inner cell pressure for sealed type Ni-MH rechargeable battery using Zr-based hydrogen storage alloy as anode (Zr-based 수소저장합금을 음극으로 사용한 밀패형 Ni-MH 2차전지의 내압특성에 관한 연구)

  • Kim, Dong-Myung;Lee, Ho;Jang, Kuk-Jin;Lee, Jai-Young
    • Transactions of the Korean hydrogen and new energy society
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    • v.8 no.2
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    • pp.79-90
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    • 1997
  • Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.

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An Optimal AP Discovery Method in 802.11 Network (802.11망에서 최적의 AP 검색 기법)

  • Lee, Daewon
    • The Journal of Korean Association of Computer Education
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    • v.15 no.5
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    • pp.55-62
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    • 2012
  • With the development of mobile communications and Internet technology, there is a strong need to provide seamless and fast connectivity for roaming devices. Generally, the mobile host (MH) may have several available networks when entering a new wireless area. However, the standard of decision for user's internet connection is provided only the subsystem identification (SSID) and signal strength of access point (AP). These two standards could not enough to decide optimal AP to the MH. Therefore, to decide the optimal AP, more information is needed. In this paper, we present additional information such as status of MH, capacity, current load, and depth of network hierarchy, by router advertisement message at layer 3. Also, we proposed decision engine (DE) on the MH that analyzes APs and decides the optimal AP automatically by AP's status information. For the MH, wireless connection period is increased, the power consumption is decreased, and the signaling overhead is reduced. For AP and router, the load balancing is provided and the network topology can also be more efficient.

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Correlation between the morning hypertension on ambulatory blood pressure monitoring and the left ventricular mass in children

  • Kim, Hyun Jung;Kim, Kyung Hee;Kil, Hong Ryang
    • Clinical and Experimental Pediatrics
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    • v.57 no.9
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    • pp.403-409
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    • 2014
  • Purpose: Although high morning blood pressure (BP) is known to be associated with the onset of cardiovascular events in adults, data on its effects in children with hypertension are limited. Our retrospective study aimed to define the clinical characteristics of children with morning hypertension (MH) and to determine its associated factors. Methods: We reviewed 31 consecutive patients with hypertension, confirmed by the ambulatory blood pressure monitoring (ABPM). We divided these patients into 2 groups: the MH group (n=21, 67.7%), morning BP above the 95th percentile for age and height (2 hours on average after waking up) and the normal morning BP group (n=10, 32.3%). We compared the clinical manifestations, laboratory results, and echocardiographic findings including left ventricular hypertrophy (LVH) between the groups. Results: The early/atrial (E/A) mitral flow velocity ratio in the MH group was significantly lower than that in the normal morning BP group. In addition, LV mass was higher in the MH group than in the normal morning BP group, although the difference was not statistically significant. The age at the time of hypertension diagnosis was significantly higher in the MH group than in the normal morning BP group (P =0.003). The incidence of hyperuricemia was significantly higher in the MH group than in the normal morning BP group. Conclusion: Older patients and those with hyperuricemia are at higher risk for MH. The rise in BP in the morning is an important factor influencing the development of abnormal relaxation, as assessed by echocardiography. Clinical trials with longer follow-up periods and larger sample sizes are needed to clarify the clinical significance of MH.