• 제목/요약/키워드: Elastic recovery

검색결과 185건 처리시간 0.029초

의치 세정제가 탄성 의치상 이장재에 미치는 효과에 관한 연구 (THE EFFECT OF DENTURE CLEANSERS ON SOFT LINING MATERIALS)

  • 장복숙;김창회;김영수
    • 대한치과보철학회지
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    • 제31권2호
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    • pp.219-235
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    • 1993
  • To determine the compatibilities of soft liming materials with denture cleansers by measuring the flexibility and elasticity and investigating the surface changes, 4 self-curing acrylic resin soft lining materials and 1 heat-curing silicone soft lining material were evaluated. 3mm thick x 20mm diameter discs of soft lining materials were individually bonded to a hard acrylic resin base as per manufacturers’instructions. Using an Instron universal testing machine, a static stress of $2kg/cm^2$ was applied for 30secs., the strain in compression was measured, giving an indication of the material’s flexibility. Elastic recovery was measured at 10secs. After removal of stress. Surface changes were investigated with Stereomicroscope. Then the specimens were immersed in 4alkaline peroxide denture cleansers and water as control group, tests were carried out at 1 day, 2 days, 7 days, 14 days and 30 days. The results were as follows : 1. Alkaline peroxide denture cleansers caused considerable porosity on the surface of selfcuring acrylic resin soft lining materials, and the most affected by the cleansers were Viscogel, Coe-Soft, Coe-Comfort, Lynal, in that order. 2. There was significant difference in flexibility between each soft lining material except for Coe-Comfort and Visco-gel, and every soft lining material was significant difference in elasticity. Especially Molloplast-B and Lynal were less flexible and more elastic than other soft lining materials(p<0.05). 3. The denture cleansers increased the flexibility and elasticity of the soft lining materials compared with control group(p<0.05), and Denalan, Polident, Kleenite, Efferdent affected the soft lining materials in that order. 4. There was significant difference in flexibility between each denture cleanser except for Denalan and Polident(p<0.05). Though Denalan and Polident, Denalan and Kleenite did not show significant difference in elasticity, other denture cleansers showed significant difference among each other(p<0.05). 5. Clinically Coe-Comfort, Coe-Soft and Visco-gel were incompatible with alkaline peroxide denture cleansers, and Lynal would be used within only 2 weeks. But Molloplast-B was compatible with alkaline peroxide denture cleansers.

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레이저 침탄된 TiZrN 코팅에서 탄소확산거동과 기계적 특성 (Carbon diffusion behavior and mechanical properties of carbon-doped TiZrN coatings by laser carburization)

  • 유현조;김태우;김성훈;조일국;이희수
    • 한국결정성장학회지
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    • 제31권1호
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    • pp.32-36
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    • 2021
  • 본 연구는 레이저 침탄된 TiZrN 코팅층의 탄소확산거동 측면과 이에 따른 기계적 특성 변화를 연구·고찰하였다. TiZrN 코팅에 탄소페이스트를 도포한 후, 레이저를 조사하여 침탄시켰다. 침탄 이후에 (111)상에 해당하는 XRD 피크가 저각으로 이동하여, 도핑된 탄소에 의한 격자팽창을 보여주었다. 아울러, 투입된 탄소의 입계 확산에 의한 결정립의 크기가 감소하였다. 침입된 탄소의 결합상태를 확인하기 위한 XPS 분석결과, 레이저의 열에너지를 통해 탄소가 TiZrN내 질소 원자와 치환되어 탄화물(TiC 또는 ZrC)을 보였다. 아울러, sp2와 sp3 혼성화 결합이 혼재하는 상태를 보여 비정질 탄소가 형성된 것을 확인할 수 있었다. 침탄 전후 TiZrN 코팅층의 단면 TEM 이미지와 inverse FFT 분석결과, 격자 중간에 물결형상이 관찰되어 결정립계 내 비정질 상의 형성을 보여주었다. 침탄 후 경도는 34.57 G Pa에서 38.24 G Pa로 증가하였으며, 마찰계수는 83 % 감소하였다. 특히, 외부 하중에 저항하는 지표로 활용되는 H/E는 0.11에서 0.15으로 증가하였고 wear rate는 65 % 개선되는 것을 확인할 수 있었다.

현장시험을 이용한 저유동성 몰탈주입공법의 보강효과에 관한 연구 (A Study on the Reinforcement Effect of Low Flow Mortal Injection Method Using Field Test)

  • 장준영;이광남;김대현
    • 지질공학
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    • 제33권4호
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    • pp.599-609
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    • 2023
  • 국내 항만 방파제의 내진보강시 현장여건, 현장상황 등으로 회수율이 불확실한 경우가 많아 문제점이 지속적으로 발생하고 있다. 따라서, 본 연구에서는 저유동성 몰탈주입 공법 적용 후 그라우팅 확인방법으로 시추조사를 통한 회수율 및 개량체의 압축강도를 분석하였으며, 추가적으로 다운홀 테스트 및 토모그래피로 탄성계수를 확인하여 지반개량 후 연약지반의 보강 증대 효과를 확인하고자 하였다. 실험결과, 다운홀테스트의 경우 BH-1번과 3번공에서 심도 28.0 m까지에 대한 지반의 평균 전단파속도는 229 m/s에서 288 m/s로 증가하였고, 심도 30.0 m까지에 대한 지반의 평균 전단파속도는 224 m/s에서 282 m/s로 증가하는 경향을 보였다. 이는 보강후 지반의 강성이 증대되어 나타난 결과로 판단된다. 토모그래피 탐사 결과, Site1번의 시료의 연약지반의 Vs가 113 m/s에서 214 m/s, Site2번 시료의 Vs는 120 m/s에서 224 m/s로 증가하였다. 이는 전단파속도에 따른 암질의 분류에서 Vs값이 180~360 m/s를 만족하는 값으로 내진보강 후의 지반의 강성이 단단한 흙으로 보강됨을 확인할 수 있다.

비용매 휘발법을 이용한 생체모사 혈액친화성 폴리락티드-카프로락톤 공중합체 필름의 제조 (Blood-compatible Bio-inspired Surface of Poly(L-lactide-co-ε-caprolactone) Films Prepared Using Poor Co-solvent Casting)

  • 임진익;김수현
    • 폴리머
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    • 제39권1호
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    • pp.40-45
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    • 2015
  • 혈항혈전성 표면의 제조를 위해 간단한 비용매 휘발 방법을 통하여 고탄성체이면서 생분해성 폴리 락티드-카프로락톤 공중합체 필름의 표면상에 연잎 구조물과 유사한 마이크로 돌기를 만들어 주었다. 표면 구조와 소수성도, 항혈전 효과 등을 시험했으며, 결정화도와 탄성회복률 등의 물리적 특성도 분석하였다. 그 결과 비용매와 메틸렌클로라이드의 혼합 부피비 1:2에서 연잎표면과 유사한 최적의 효과를 얻었으며, 이때 수접촉각은 $124^{\circ}$였다. 혈소판 부착시험에서는 처리하지 않는 군에 비해 약 10%만 부착되는 효과를 확인할 수 있었다.

테이핑요법 간호중재가 재가뇌졸증 환자의 관절운동범위, 통증 및 우울에 미치는 효과 (The Effects of the Taping Therapy on Range of Motion, Pain and Depression in Stroke Patient)

  • 권선숙
    • 대한간호학회지
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    • 제33권5호
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    • pp.651-658
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    • 2003
  • Purpose: The purpose of this study was to test the effect of Taping therapy on Range of Motion, pain, and depression in stroke patients in the home without complete recovery as a means of nursing intervention. Method: Twenty seven subjects out of fifty four people who were attending in the stroke self-help group in one community health center in S city were asked to participate in this Quai-experimental study. The Taping therapy was a method that stick to the illness area and the point of pressure pain, the elastic and cross tape without medicine treatment with domestic products. Nursing intervention was independently completed by researcher once a week over two period of 12 weeks from September 2001 to March 2002 year. Data were analyzed using the SPSS win. The homogeneity between the experimental group and control group was test by x2 and t-test. The difference of experimental before and after were tested by the unpaired t-test. Result: The shoulder joint flexion and abduction, the elbow joint flexion and extension, the hip joint flexion, and the flexion of knee joint in the ROM of the experimental group were significantly improved over those of the control group. In difference of pain, rest and painful movement, the experimental group were significantly decreased over those of the control group. The difference of depression in experimental before and after was significantly decreased in the experimental group over those of the control group. Conclusion: The Taping therapy intervention proved effect pain relief and depression decrease as well as promote of range of motion.

고령사회에 대비한 노인 건강 의류 제품 개발을 위한 기초 연구 - 니트 소재 압박복을 중심으로 - (Physical Properties of Knitted Fabrics on Knitting Structure for Medical Compression Garments)

  • 박명자;상정선
    • 복식문화연구
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    • 제19권2호
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    • pp.334-345
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    • 2011
  • A study on compressive garments guarantee the required pressure and form depending on the type of disease and the state of injury can be used in the preventive treatment of cardiovascular disease. This research is to provide a preliminary data to develop medical clothing products, especially knitted compression garments. Starting from analyzing knitted structure of imported pressure goods to apply to test samples, 11 kinds of knitted stretchy fabrics were manufactured under the various knitting conditions, then their tensile, mechanical and hand properties were measured. In comparison size changes by knitting structure, tuck stitch applied structure showed an increase in course direction and decrease in wale direction. Float stitch applied structure indicated the contraction of size in width because of unformed loops and floated yarn on the technical back of fabric. As a result of tensile properties in tuck and float applied structure, tensile strength was increased in the course direction. On the other hand, the more loops overlapped due to the tuck and float stitch, the more decreased their elongation and elastic recovery were. In case of mechanical properties, as the tuck and float stitch were overlapped double or triple the bending and shearing properties were risen. Accordingly, the drape of fabric becomes stiff, and its surface becomes rough and uneven. The measurements of hand properties showed that the value of KOSHI, FUKURAMI NUMERI in tuck and float applied structure are higher than the plain structure. This results from the relationship between the mechanical and hand properties.

나노/마이크로 인덴터와 AFM을 이용한 스퀴즈 캐스트 A356 합금의 시효경화특성 평가 (Evaluation of Age-Hardening Characteristics of Squeeze-Cast A356 Alloy by Using Micro/Nano Indenter with AFM)

  • 윤성원;김현일;강충길
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1398-1401
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    • 2005
  • The nano/microstructure, the aging response (in T5 heat treatment), and the mechanical/tribological properties of the eutectic regions in squeeze-cast A356 alloy were investigated using nano/micro-indentation and mechanical scratching, combined wit optical microscopy and atomic force microscope(AFM). Most eutectic Si crystals in the A356 alloy showed a modified morphology as fine-fibers. The loading curve for the eutectic region was more irregular than that of the primary Al region due to the presence of various particles of varying strength. In addition, the eutectic region showed lower pile-up and higher elastic recovery than the primary Al region. The aging responses of the eutectic regions in the squeeze-cast A356 alloys aged at $150^{\circ}C$ for different times(0, 2, 4, 8, 10, 16, 24, 36 and 72 h) were investigated. As the aging time increased, acicular Si particles in the eutectic regions gradually came to a fine structure. Both Vickers hardness ($H_V$) and indentation ($H_{IT}$) test results showed almost the same trend of aging curves, and the peak was obtained at the same aging time of 10 h. A remarkable size-dependence of the tests was found. The friction coefficient for the eutectic region was lower than that for the primary Al region.

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열처리 온도가 Poly(trimethylene terephthalate)(PTT) 섬유의 역학적 성질과 미세구조에 미치는 효과 (The Effects of Annealing Temperature on The Physical Properties and Fine Structure of Poly(trimethylene terephthalate)(PTT) Fibers)

  • 정경희;이언필;이재호
    • 한국의류산업학회지
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    • 제15권6호
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    • pp.985-992
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    • 2013
  • Polytrimethylene terephthalate(PTT) offers several advantageous properties such as good tensile strength, uniformity, stiffness, toughness, UV stability, resilience, stain resistance, outstanding elastic recovery, and dyeability. The effects of annealing temperature on physical properties and the structure of PTT filaments and yarn were investigated by measuring wide-angle X-ray diffraction (WAXD), density, optical birefringence, dynamic visco elasticity, and tensile testing. The intensity of maximum tan ${\delta}$ decreased and the temperature of maximum tan ${\delta}$ shifted to a higher temperature as the annealing temperature of filaments increased; however, it shifted to a lower temperature when the annealing temperature exceeded $130^{\circ}C$. In addition, crystallinity, density and D-spacing of (010) crystal face increased as the annealing temperature increased. Optical birefringence and specific stress were almost constant up to $100^{\circ}C$ and then decreased above $130^{\circ}C$. The shrinkage of PTT filament is 0 in boiling water when annealed above $130^{\circ}C$; consequently, the use of annealed fiber above $130^{\circ}C$ can remove thermal instability when dyeing PTT fiber. In the case of yarns, the thermal stability and physical properties of yarns showed the best effect when the ply number is less than 5, twist number is less than 400tpm, and the annealing time is 20minutes.

실시간 탄성초음파를 이용한 만성 뇌졸중 후 편마비 환자의 상지 강직에 대한 사암침 효과 연구 (Study of the Effects of Sa-am Acupuncture on Upper Limb Spasticity in Patients with Chronic Post-stroke Hemiparesis using Real-time Sonoelastography)

  • 백경민;권동락;박기영
    • 대한한방내과학회지
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    • 제35권1호
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    • pp.1-11
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    • 2014
  • Objectives : To investigate the effects of Sa-am acupuncture on muscle architecture and elastic properties of the spastic elbow flexor and to evaluate the correlation between clinical findings and parameters of real-time sonoelastography (RTS) in patients with chronic post-stroke hemiparesis. Materials and Methods : Seven patients (five males, two females) with chronic post-stroke hemiparesis were included. Sa-am acupuncture of Ganseunggyeok (肝勝格: LU8 LR4 補, HT8 LR2 瀉) was applied to the unaffected side 3 times a week for 4 weeks. During each acupuncture treatment period, patients were requested to exercise their affected arm, and spasticity and functional recovery outcomes of the affected arm were evaluated before and after Sa-am acupuncture treatment. Clinical outcomes were assessed using motricity index (MI), modified Ashworth scale (MAS), Fugl-Meyer assessment scale (FMA) and modified Barthel index (MBI) for elbow flexor spasticity. RTS images indicate the relative hardness of the examined muscles ranged from red (hard) to purple (soft) for color-scale, and from black (hard) to white (soft) for hue scale. Color and hue histograms of the biceps brachii and brachialis were analyzed using Image J software, and median red, blue, and hue pixel intensity were obtained. Results : MI and FMA score significantly increased and MAS score significantly decreased (p<0.05). F-wave maximal amplitude of affected abductor pollicis brevis significantly decreased (p<0.05). Muscle thickness of affected brachialis significantly increased (p<0.05). Red and green pixel intensity of affected brachialis significantly decreased (p<0.05). Conclusions : Our study revealed that Sa-am acupuncture is effective as a useful and safe treatment for spasticity in chronic post-stroke hemiparesis.

크릴(Euphausia superba) 육을 이용한 인스턴트 죽의 품질특성 평가 (Food Quality Characteristics of Instant Gruel Prepared with Peeled Krill Euphausia superba Meat)

  • 정해림;최은혜;이양봉;전병수;김선봉
    • 한국수산과학회지
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    • 제46권4호
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    • pp.343-350
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    • 2013
  • Instant krill gruel was produced using peeled Antarctic krill Euphausia superba as a high nutritional ingredient and the food quality was investigated. The food quality of krill gruel was examined by measuring proximate composition, cholesterol, calorie, Hunter color value, total amino acids, fatty acids, fluoride, viscoelastic properties, and by sensory evaluation. The krill gruel had a moisture content of 87% and a pH of 6.65. The krill gruel contained 51 kcal/100 g, and 0.1% fat and 3.5 mg/100 g cholesterol. Its fatty acid composition exhibited high levels of unsaturated fatty acids. The levels of oleic acid and linolenic acid were high, and n-3, n-6, and n-9 fatty acid contents ranged from 1% to 6%. The total amino acid content was 2132 mg/100 g, and the levels of glutamic acid, aspartic acid, leucine, alanine, and arginine were particularly high. Essential amino acids accounted for over 30% of the total amino acids. Fluoride level in the krill gruel was 3.07 mg/kg. The viscoelastic properties of the krill gruel were determined as 6.28 Pa at shear stress of 2.51 Pa. In the recovery test, the elastic restoring force after deformation was low.