• Title/Summary/Keyword: Lubricant

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A Study on Constipation (변비(便秘)에 관(關)한 동서의학적(東西醫學的) 고찰(考察))

  • Ryu, Bong-Ha;Cho, Nam-Hee
    • The Journal of Internal Korean Medicine
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    • v.21 no.1
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    • pp.169-180
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    • 2000
  • Objectives : To satisfy the demand of good treatment of constipation Methods : we investigated the literatures of Oriental Medicine about Constipation. Results: 1. There are three categories of etimological factors of constipation, that is, endogenous, exogenous and non-exo-endogenous factor. The endogenous factor is caused by seven emotions, called depression of Ki and stagnation of Ki. The exogenous factor is six excessive atmospheric influences, for example, wind, cold, dampness, heat and dryness. And the non-exo-endogenous factors are overfatigue, improper diet, stagnated blood and deficiency of Ki and blood that comes from old age, long disease and after delivery. 2. Classification: According to cause of disease it is classified by constipation due to cold, heat, wind, dryness, retention of undigested and phlegm. According to Internal Organs there are constipation due to deficiency syndrome of the stomach, excess syndrome of the stomach, deficiency syndrome of kidney and splenic constipation. And Differentiation of syndromes according to Ki and blood, there are constipation of deficiency type and excess type. There are constipation due to stagnation and deficiency of Ki, deficiency of blood and stagnated blood. 3. Principles and Methods of treatment 1) Herbal Medicine (1) Excess type [1] Constipation due to heat : Seunggitang(承氣湯) and Majainwhan(麻子仁丸) [2] Constipation due to stagnation of Ki : Samatang(四磨湯) and Yukmatang(六磨湯) (2) Deficiency type [1] Constipation due to deficiency of Ki : Whanggitang(黃?湯) [2] Constipation due to deficiency of blood: Yunjangwhan(潤腸丸) [3] Constipation due to cold : Jechunjun(濟川煎) and Banyuwhan(半硫丸) 2) Enema therapy: It is a method to induce defecation by honey or pig's bile juice for weak people. 3) Acupuncture and Moxibustion: Acupoints used to treat constipation are BL25, ST25 and TE6. Moxibustion at CV8, CV6 is good for constipation due to cold. (4) Diet therapy: It is very important that we eat meals regularly and defecate on the same time even if you don't. And we have to eat food like fruits, vegetables and beans. (5) finger pressure: Finger pressing around these points like ST25, SP25, BL25, BL31, BL32, BL33 and BL34 is good for it. (6) Kigong therapy: Abdominal breathing (7) Old man' s constipation: Hip bath or diet therapy is commended. Laxation with lubricant like Supungyunjangwhan(搜風潤腸丸) is used. (8) Women' s constipation: After delivery, we have to administer tonifying prescription Sipjundaebotang(十全大補湯) and enema can be used. Conclusion : We have to examine the cause of disease and bowl movement carefully. After comprehensive analysis of the data gained by the four methods of diagnosis, we diagnose and treat patients on the base of overall of symptoms and signs.

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The Effect of Si Content on the Tribological Behaviors of Ti-Al-Si-N Coating Layers (Ti-Al-Si-N 코팅막의 마모거동에 미치는 Si 함량의 영향)

  • Jin, Hyeong-Ho;Kim, Jung-Wook;Kim, Kwang-Ho;Yoon, Seog-Young
    • Journal of the Korean Ceramic Society
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    • v.42 no.2 s.273
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    • pp.88-93
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    • 2005
  • Ti-AI-Si-N coating layers were deposited on WC-Co substrates by a hybrid system of arc ion plating and sputtering techniques. The coatings were prepared with different Si contents to investigate the effect of Si content on their mechanical properties and microstructures. The dry sliding wear experiments were conducted on Ti-AI-Si-N coated WC-Co discs at constant load, 3N, and sliding speed, 0.1 m/s with two different counterpart materials such as steel ball and zirconia ball using a conventional ball-on-disc sliding wear apparatus. In the case of steel ball, the friction coefficient of Ti-AI-Si-N coating layers became lower than that of Ti-AI­N coating layers. The friction coefficient decreased with increasing of Si content due to adhesive wear behavior between coating layer and steel ball. On the contrary, in the case of zirconia ball, the friction coefficient increased with increasing of Si content, indicating that abrasive wear behavior was more dominant when the coating layers slid against zirconia ball.

Oil Absorptive Properties of Polypropylene Knit Fabric Treated with Oleophilic Acrylic Resin (친유성 아크릴 수지로 처리된 폴리프로필렌 편직물의 유흡착 성질)

  • Jeong, Hwa-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.528-535
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    • 2016
  • Two types of oleophilic acrylic prepolymers were prepared by the solution copolymerization of either ethyl acrylate (EA) or lauryl acrylate (LA) with hydroxy ethyl acrylate (HEA). For the formation of oil-absorbent materials, a mixed solution of the prepolymer and hexamethylene diisocyanate (HDI) as a cross-linker in toluene was applied to polypropylene knit velvet fabric through the conventional pad-dry-cure procedure. The gel fraction of the crosslinked resin, EA-HEA-HDI, increased with increasing feed ratio of HEA to total acrylate or HDI concentration. The oil absorbancy and retention ratio of the prepared materials were compared according to the add-on ratio of resin to fabric, and were assessed with n-decane, toluene, soybean oil, lubricant and bunker C oil as test oils. The optimal oil absorbancy of the materials were observed at around 6% of the add-on ratio for all these oils except for soybean oil. On the other hand, the oil retention ratio increased as the add-on ratio increased. Futhermore, heavier and more viscous oil generally showed higher oil retention ratios. In addition, the oil absorbancy of the materials treated with LA-HEA-HDI resin was higher than that treated with EA-HEA-HDI resin, which showed that the acrylic resins are more absorptive with increasing length of their side alkyl chain.

THE EFFECTS OF SURFACE CONTAMINATION ON THE SHEAR BOND STRENGTH OF COMPOMER

  • Heo, Jeong-Moo;Lee, Su-Jong;Im, Mi-Kyung
    • Proceedings of the KACD Conference
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    • 2001.11a
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    • pp.577-577
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    • 2001
  • The lastest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not blown dry but left moist before application of the bonding primer. Ideally, the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during preparation of a restoration. The aim of this study was to evaluate the effect of contamination by hem-ostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were cleaned from soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive paper on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows: Group 1 : Dentin surface was not etched and not contaminated by hemostatic agents. Group2 : Dentin surface was not etched but was contaminated by Astringedent (Ultradent product Inc., Utah, U.S.A.). Group3 : Dentin surface was not etched but was contaminated by Bosmin (Jeil Phann, Korea.). Group4 : Dentin surface was not etched but was contaminated by Epri-dent (Epr Industries, NJ, U.S.A.). Group5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6 : Dentin surface was etched and contaminated by Astringedent. Group7 : Dentin surface was etched and contaminated by Bosmin. Group8 : Dentin surface was etched and contaminated by Epri-dent. Group9 : Dentin surface was contaminated by Astringedent. The contaminated surface was rinsed by water and dried by compressed air. Group10 : Dentin surface was contaminated by Bosmin. The contaminated surface was rinsed by water aud dried by compresfed air. Group 11 : Dentin surface was contaminated by Epri-dent. The contaminated surface was rinsed by water and dried by compresfed air. After surface conditioning, F2000 was applicated on the conditoned dentin surface. The teeth were thermocycled in distilled water at $5^{\circ}C\;and\;55^{\circ}C$ for 1000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the lmife-edge shearing rod of the Universal testing machine(Zwick 020, Germany) running at a cross head speed of 1.0mmimin. There were no significant differences in shear bond strength between groups 1 and group 3 and 4, but group 2 showed significant decrease in shear bond strength compared with group 1. There were no significant differences in shear bond strength between group 5 and group 7 and 8, but group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

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A Pilot Study on Environmental Factors Contributing to Childhood Home Slip-Down Injuries (가정 내 낙상으로 인한 아동 손상의 유발 환경 인자에 관한 예비연구)

  • Ryu, Jeong-Min;Seo, Min Hoo;Kim, Won-Young;Kim, Won;Lim, Kyoung-Soo
    • Journal of Trauma and Injury
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    • v.22 no.1
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    • pp.51-56
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    • 2009
  • Purpose: The purpose of this study was to investigate environmental factors contributing to childhood home slip-down injuries. Methods: Among a total of 2,812 injured children in our Customer Injury Surveillance System (CISS), we performed a prospective study on 262 children with home slip-down injuries who visited the pediatric emergency department of Asan Medical Center between March 2008 and February 2009. We made a frequency analysis on parameters such as activities just before the accident, the presence of any obstacles or lubricant materials, specific home place in the home where the injuries occurred, flooring materials on which the slip-down happened, additional objects hit after slip down, the site and kind of injury, the duration of therapy, and the disposition. Results: Walking was the most common activity just before the injury. Because rooms and bathrooms were most common places in the home for slip down injuries, laminated papers/ vinyl floor coverings and tiles were the most common flooring materials used in the places where the injuries occured. Most commonly, no obstacles caused the children to slip down, but the furniture, stairs, doorsills, wetness, or soapy fluid followed after that. Over half of the children who slipped (58%) also collided with other than the floor itself after the slip-down, most common objects hit were the edges of the furniture, and doorsills, followed by stairways. The head and neck were the most commonly injured sites, and a laceration was the most common kind of injury. Most children needed less than 1 week of therapy, only 4 children (1.53%) admitted. There were no mortalities. Conclusion: The environmental factors contributing to slip-down injuries were the bathroom, laminated papers/vinyl floors, the furniture, stairs, doorsills, and wetness or soapy fluid. Especially, the furniture, stairs, and doorsills can be both primary obstacles and secondary collision objects. For the safety of our children, we must consider these factors on housing, when decorating or remodeling our house.

Catalytic Oxidation of Volatile Organic Compounds Over Spent Three-Way Catalysts (배기가스 정화용 폐 자동차 촉매를 이용한 휘발성 유기화합물의 제거)

  • Shim, Wang Geun;Kim, Sang Chai
    • Applied Chemistry for Engineering
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    • v.19 no.5
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    • pp.574-581
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    • 2008
  • The optimum regeneration conditions for the regeneration of three way spent catalysts (TWCs), which were taken from automobiles with different driving conditions, were investigated to evaluate the suitability as alternative catalysts for removing VOCs. The spent catalysts were washed with five different acids ($HNO_3$, $H_2SO_4$, $C_2H_2O_4$, $C_6H_8O_7$, and $H_3PO_4$) to remove contaminants and examine the optimum conditions for recovering the catalytic activity. The physicochemical properties of spent and its regenerated TWCs were evaluated by using nitrogen adsorption-desorption isotherms, XRD, and ICP. The relative atomic ratios of contaminants and platinum group metals (PGMs) of the spent TWCs were greatly dependent on the placed positions. The main contaminants formed were lubricant oil additives and metallic components. Also, the regeneration treatment increased the PGMs ratio, BET surface area, and average pore diameter of TWCs. The catalytic activity results indicated that the spent TWCs have the possibility for removing VOCs. Moreover, the employed acid treatments greatly enhanced the catalytic activity of the spent TWCs. Especially, nitric and oxalic acids provided the most improvement in the catalytic behavior. The catalytic activities of the regenerated TWCs were significantly influenced by the containing platinum ratios rather than the removal ratios of contaminants and the changes in the structural properties offered by the acid treatments.

Mechanical Properties and Wear Behaviour of $Al/SiC/Al_{2}O_{3}$ Composite Materials ($Al/SiC/Al_{2}O_{3}$복합재료의 기계적 성질 및 마멸특성)

  • 임흥준;김영한;한경섭
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2498-2508
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    • 1993
  • $Al/SiC/Al_{2}O_{3}$ hybrid composites are fabricated by squeeze infiltration method. From the misconstructive of $Al/SiC/Al_{2}O_{3}$ hybrid composites fabricated by squeeze infiltration method, uniform distribution of reinforcements and good bondings are found. Hardness value of $Al/SiC/Al_{2}O_{3}$ hybrid composites increases linearly with the volume fraction of reinforcement because SiC whisker and $Al_{2}$O$_{3}$ fiber have an outstanding hardness. Optimal aging conditions are obtained by examining the hardness of $Al/SiC/Al_{2}O_{3}$ hybrid composites with different aging time. Tensile properties such as Young's modulus and ultimate tensile strength are improved up to 30% and 40% by the addition of reinforcements, respectively. Failure mode of $Al/SiC/Al_{2}O_{3}$ hybrid composites is ductile on microstructural level. Through the abrasive wear test and wear surface analysis, wear behaviour and mechanism of 6061 aluminum and $Al/SiC/Al_{2}O_{3}$ hybrid composites are characterized under various testing conditions. The addition of SiC whisker to $Al/SiC/Al_{2}O_{3}$ composites gives rise to improvement of the wear resistance. The wear resistance of $Al/SiC/Al_{2}O_{3}$ hybrid composites is superior to that of Al/SiC composites. The wear mechanism of aluminum alloy is mainly abrasive wear at low speed range and adhesive and melt wear at high speed range. In contrast, that of $Al/SiC/Al_{2}O_{3}$ hybrid composites is abrasive wear at all speed range, but severe wear when counter material is stainless steel. As the testing temperature increases, wear loss of aluminum alloy decreases because the matrix is getting more ductile, but that of $Al/SiC/Al_{2}O_{3}$ hybrid composites is hardly varied. Oil lubricant is more effective to reduce the wear loss of aluminum alloy and $Al/SiC/Al_{2}O_{3}$ hybrid composites at high speed range.

The Concentrations of Endocrine Disrupter (PCBs and DDE) in the Serumand Their Predictors of Exposure in Korean Women (일부 한국 성인 여성들의 혈중 내분비계 장애물질 농도 및 그 노출요인의 연구)

  • 민선영;정문호
    • Journal of Environmental Health Sciences
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    • v.27 no.2
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    • pp.127-137
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    • 2001
  • Polychlorinated biphenyls(PCBs) are halogenated aromatic compounds with the empirical formula $C_{12}$ $H_{10-n}$C $l_{n}$(n=1~10), and are a mixture of possible 209 different chlorinated congeners. PCBs were widely used as dielectric fluids for capacitors and transformers, plasticizers, lubricant inks and paint addirives. Once released into the environment, PCBs persist for years because they are so resistant to degradation. In addition to their persistence in the environment, PCBs in ecological food chains undergo biomagnification because of their high degree of lipophilicity. In 1970s, the worldwide production of PCBs was ceased and the import of PCBs was prohibited since 1983 in Korea. In spite of these actions, many PCBs seems to be still in use. The environmental load of PCBs will continue to be recycled through air, land, water, and the biosphere for decades to come. This study was conducted to measure the concentrations of PCBs in the serum samples of 112 women by GC/MSD and GC/ECD. The main results of this study were as follows. 1. PCBs were detected in all samples. The mean $\pm$SD levels of PCBs in the serum were 3.613$\pm$0.759 ppb, and median were 3.828 ppb. 2. The correlation coefficients of the concentrations of 13 PCB congeners were from minimum, 0.7913 to maximum, 0.9985, and all was significant(p=0.0001). The correlation coefficient between the concentrations of PCBs and p,p'-DDE was 0.9641(p=0.0001). 3. There was a positive association between age and PCBs' concentrations (simple linear regression ; $R^2$=0.86, $\beta$=0.08023, p<0.001). 4. There was a positive association between total lipids in the serum and PCBs' concentrations (simple linear regression ; $R^2$=0.7058, $\beta$=0.00486, p<0.001). 5. For possible predictors of PCBs and p,p' -DDE levels in the serum, age adjusted model (Y=$\beta$$_{0}$+$\beta$$_1$age+ $B_2$X) was applied. For BMI, major residential area, wether to eat caught fish by angling, where to eat caught fish by angling(by parents in the past), fish consumption, meat consumption, meat consumption, and dairy consumption, there was no association. For total conception frequency and lactation frequency and lactation period, there was negative association.ion.

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Study on Analysis of Transfer Torque and Improvement of Transfer Torque in Non-Contact Permanent Magnet Gear (비접촉 영구자석 기어의 전달토크 분석 및 전달토크 향상에 대한 연구)

  • Park, Gyu-Sang;Kim, Chan-Ho;Kim, Yong-Jae
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.181-188
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    • 2015
  • The non-contact permanent magnet gear has advantages of high efficiency and improved reliability. It has other advantages of no mechanical friction loss, very little noise and vibration, and no need for lubricant. With these advantages, the non-contact permanent magnet gear that solves the physical contact problem of the mechanical gear has drawn attention. Due to this unique non-contact characteristic, the non-contact permanent magnet gear which is capable of non-contact torque transmission has replaced mechanical gear. The mechanical gears which is in many fields of the modern industry, is used mostly for power transmitting mechanical devices. However, it also has the problem of a low torque density, which requires improvement. In this paper, a novel pole piece shape is proposed in order to improve the problem of low torque density of the non-contact permanent magnet gear. The experiment data required for predicting the relationships among them are obtained using finiteelement Operating method based on two-dimensional (2-D) numerical analysis. Therefore, this paper derived an optimal model for thenon-contact permanent magnet gear with the novel pole piece using the Box-Behnken design, and the validity of the optimal design of the proposed pole piece shape through variance analysis and regression analysis demonstrated. In this paper, we performed the thransfer torque analysis in order to improve the torque density and power density, we have performed on optimal design of proposed pole piece shape using box-behnken.

INFLUENCE OF TUNGSTEN CARBIDE/CARBON COATING ON THE PRELOAD OF IMPLANT ABUTMENT SCREWS (임플랜트 지대주 나사의 텅스텐 카바이드/탄소 코팅이 전하중에 미치는 영향에 관한 연구)

  • Choi Jin-Uk;Jeong Chang-Mo;Jeon Young-Chan;Lim Jang-Seop;Jeong Hee-Chan;Eom Tae-Gwan
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.2
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    • pp.229-242
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    • 2006
  • Statement of problem: In order to increase preload with reducing the friction coefficient, abutment screws coated with pure gold and Teflon as dry lubricant coatings have been introduced. But the reported data indicate that if screw repeated tightening and loosening cycle, an efficiency of increasing preload was decreased by screw surface wearing off. Purpose: This study was to evaluate the influence of tungsten carbide/carbon coating, which has superior hardness and frictional wear resistance, on the preload of abutment screws and the stability of coating surface after repeated closures. Material and method: The rotational values of abutment screws and the compressive forces between abutment and fixture were measured in implant systems with three different joint connections, one external butt joint and two internal cones. Moreover the stability and the alteration of coating surface were examined by comparison of the compressive force and the removable torque values during 10 consecutive trials, observation with scanning electron microscope and analyzed the elemental composition with energy dispersive x-ray spectroscopy Results and conclusion: 1. Application of coating resulted in significant increase of compressive force in all implant systems(P<.05). The increasing rate of compressive force by coating in external butt joint was gloater than those in internal cones (P<.05). 2. Coated screw showed the significant additional rotation compared to non-coated screw in all implant systems (P<.05). There were no significant differences in the increasing rate of rotation among implant systems (P>.05). 3. Removable torque values were greater with non-coated screw than that with coated screw (P<.05). 4. Coated screw showed insignificant variations in the compressive forces during 10 consecutive trials(P>.05) 5. After repeated trials, the surface layer of coated screw was maintained relatively well. However surface wearing and irregular titanium fragments were found in non-coated screw.