• Title/Summary/Keyword: reinforcing effect

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The Effect of Glass Fiber Reinforcing Materials and Thermocycling on the Transverse Strength of Denture Base Resin (유리 섬유 의치상 레진 강화재와 열 순환이 의치상 굽힘 강도에 미치는 영향)

  • Jin, Sung-Eun;Cho, In-Ho
    • Journal of Dental Rehabilitation and Applied Science
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    • v.29 no.4
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    • pp.327-336
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    • 2013
  • This study aimed to investigate the reinforcing effect of two kinds of glass fiber, Quarts Splint$^{TM}$ Mesh and SES MESH$^{(R)}$ and to evaluate the effect of the thermocycling on the transverse strength of the denture base and on the reinforcing effect of the reinforcements. 20 specimens of the size of $2.5{\times}10.0{\times}65.0mm$ were fabricated for each group; control group, metal mesh reinforcement group, Quarts Splint$^{TM}$ Mesh reinforcement group and SES MESH$^{(R)}$ reinforcement group. To find the difference made by the thermocycling, 10 specimens of each reinforcement group were treated by thermocycling. 3-point bending test was performed to measure the transverse strength of the denture base resin. The specimens reinforced with SES MESH$^{(R)}$ and Quarts Splint$^{TM}$ Mesh showed significantly higher transverse strength than the control group (P<.05), and significantly lower transverse strength than the specimens reinforced with the metal mesh (P<.05). Thermocycled specimens were lower in transverse strength than non-thermocycled specimens in the control group, metal mesh group, Quarts Splint$^{TM}$ Mesh group and SES MESH$^{(R)}$ group, however significant difference (P<.05) was found only in the control group.

Analysis of YoungSu & Wonbang Acupuncture Method by the Measurement of Physiological Signals on Acupoints (영수보사(迎隨補瀉)와 원방보사(圓方補瀉) 수기법(手技法)의 정량적(定量的) 연구(硏究))

  • Na, Chang-Su;Park, Chan-Kyu;Jang, Kyung-Sun;So, Cheal-Ho
    • Journal of Acupuncture Research
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    • v.17 no.1
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    • pp.43-54
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    • 2000
  • Previously two papers dealing with YoungSu(against the meridian course and following the course of the meridian) Acupuncture were published by our group. Here we are reporting the further analysis of YoungSu and WonBang(by twisting and rotating the needle) acupuncture methods. It is very important to understand objectively the Qi variation induced by the reinforcing-reducing manipulation method in the acupuncture therapy. We decided the medical treatment by utilizing the PyongChi Method (a kind of method to figure out the way of treatment by observing the unbalanced state of five phases). The Qi variation in the meridian treated by YoungSu and WonBang, the recovery of five phases deviation were measured by choosing single acupoint instead of complex acupoints. By using Youngsu and WonBang, we increased or decreased the Qi of the phase which caused the unbalanced state. We observed whether the Qi of the treated meridian can be increased and if the state of unbalance can be recovered. To achieve the effect of reinforcing-reducing, we needed a correct choice of treating method and a selection of a proper meridian in advance. This study was carried out by adding another way of acupuncture from the previous paper. We discovered that the effects of reinforcing-reducing by each manipulation method could be superposed each other when two counteracting Youngsu and WonBang methods were treated at the left and the right side of human body which was correspondent with our previous paper. We found that the Qi variation of the treated meridian, which was induced by Youngsu and WonBang, was linearly proportional to the reduction of five phase deviations. The slope of Qi variation was almost similar (y = -0.413x - 0.138) as that of previous paper (y = -0.266x - 0.038, Y = -0.446x - 0.079). It is assumed that the addition of other basic methods on the top of reinforcing-reducing manipulation method would magnify the effect of acupuncture.

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An Outlook of the Oriental and Western Medical Diagnosis and Treatment on Gastric Cancer (위암(胃癌)의 동서의학적(東西醫學的) 진치(診治) 개황(槪況))

  • Kim, Byeong-Ju;Moon, Goo
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.100-116
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    • 1996
  • Gastric cancer shows the most high friquency in cancers that occurs in Korea. The western medicine treatment for gastric cancer has radiation and surgery, chemical treatment. While, oriental medicine cures the gastric cancer by herb-drugs, acupunture , moxa and srigma. With just one way of treating gastric cancer can't be effective remedy. Because each medicine has a strength and weakness. Thus, it is effective treatment when two medicine combins and supplement each other. We got the following result about a trend of oriental and westernal combination treatment for gastric cancer through studing records. 1. The western medicine treats gastric cancer patient with surgery first and right after surgery. They need on assembly treatent such as chemical and immune treatment. In oriental medicine, they treats gastric cancer patients with differentiation of symptone and signs and treatment(辨證施治)[for example:incoordination between liver and stomach(肝胃不和), insufficiency of spleen and stomach(脾胃虛弱), stagnation of blood stasis and toxic agent(瘀毒內阻), deficiency of yin by stomach heat(胃熱傷陰), reinforcing both qi and blood(氣血雙虧), stagnation of damp-phlegm(痰濕凝結)] and cure for them by acupuncture and stigma, too. 2. In combination with oriental and western medical treatment principle of gastric cancer by each stage is as follows. First stage and second stage gastric cancer is cured with radical surgery mainly. After operation, the herb of invigoration of the spleen(健脾), coordination of the stomach(和胃), and smoothing the liver and regurating the circulation of qi(疏肝理氣), is used for good gastroenteric condition. The second stage patients can be concidered using in combination with chimical treatment. The third stage gastric cancer is treated with radical surgery or with temporizing surgery. After those surgery, herb-drugs treatment is used jointly. The fourth stage patients who have no extensively metastasis or local contraindication can undergo temporizing and curcuit surgical operation. Herb-drugs and chemical treatments are used together for patients after operating. If he has operating contraindication, he would be treated with herb-drugs and chemical treatment. 3. In case of using in combination with oriental and western medical treatment as follows. As for herb-drugs with chemical treatment, reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach(健脾和胃), reinforcing liver and kidney(滋補脾腎), clear out the heat and relieve the toxic agent(淸熱解毒), can be used and with radiation treatment, clear out the heat and relieve the toxic agent(淸熱解毒), promoting the production body fluid and moisturizing the vicera(生津潤燥), reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach (健脾和胃), reinforcing liver and kidney(滋補肝腎) etc, can be used. 4. According to the research of oriental and western medical combination treatment are the 5-year-survival degree with oriental and western medicine combination treatment was for better than that just with oriental or western medical treatment. Especially, it has good effect on the third, fourth stage gastric cancer. That is, the middle and the end of stage gastric cancer. 5. The merits of oriental and western medicine combination treatment are lengthers one's life and diminish the bad effect of chemical treatment and radiation treatment be near completion, prevent from relapsing, maintain the balance in their eveirenment of body and improve immunity.

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Stress-strain behavior and toughness of high-performance steel fiber reinforced concrete in compression

  • Ramadoss, P.;Nagamani, K.
    • Computers and Concrete
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    • v.11 no.2
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    • pp.149-167
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    • 2013
  • The complete stress-strain behavior of steel fiber reinforced concrete in compression is needed for the analysis and design of structures. An experimental investigation was carried out to generate the complete stress-strain curve of high-performance steel fiber reinforced concrete (HPSFRC) with a strength range of 52-80 MPa. The variation in concrete strength was achieved by varying the water-to-cementitious materials ratio of 0.40-0.25 and steel fiber content (Vf = 0.5, 1.0 and 1.5% with l/d = 80 and 55) in terms of fiber reinforcing parameter, at 10% silica fume replacement. The effects of these parameters on the shape of stress-strain curves are presented. Based on the test data, a simple model is proposed to generate the complete stress-strain relationship for HPSFRC. The proposed model has been found to give good correlation with the stress-strain curves generated experimentally. Inclusion of fibers into HPC improved the ductility considerably. Equations to quantify the effect of fibers on compressive strength, strain at peak stress and toughness of concrete in terms of fiber reinforcing index are also proposed, which predicted the test data quite accurately. Compressive strength prediction model was validated with the strength data of earlier researchers with an absolute variation of 2.1%.

Analysis on the Behavior of Reticulated Root Piles for Reinforcing Footing using Computer Program (컴퓨터 프로그램을 이용한 기초보강용 그물식 뿌리말뚝의 거동 분석)

  • 박영호;변광욱
    • Proceedings of the Korean Geotechical Society Conference
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    • 1991.10a
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    • pp.348-361
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    • 1991
  • When reinforcing strip footing on a sand 8round with reticulated root piles, reinforcing effect depends on the length , number, cross sectional area, penetration angle, spacing, and Young's modulus of piles. the mode of action of reinfocement tendons in soil isn't one of carring developed tensile stresses but of anisotropic(uni-directional) reduction or even supression of one normal strain rate. R. H. Bassett and N. C. Last proposed that the reinforcement should be located on the direction of minor strain rate which coincides with the tensile strain rate in the velocity characteristics. Based on this proposal the author carried out a series of 2 - dimentional finite element analysis which varies the parameters mentioned above.

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The influence of EAF dust on resistivity of concrete and corrosion of steel bars embedded in concrete

  • Almutlaq, Fahad M.
    • Advances in concrete construction
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    • v.2 no.3
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    • pp.163-176
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    • 2014
  • Essentially, when electrical current flows easily in concrete that has large pores filled with highly connective pore water, this is an indication of a low resistivity concrete. In concrete, the flow of current between anodic and cathodic sites on a steel reinforcing bar surface is regulated by the concrete electrical resistance. Therefore, deterioration of any existing reinforced concrete structure due to corrosion of reinforcement steel bar is governed, to some extent, by resistivity of concrete. Resistivity of concrete can be improved by using SCMs and thus increases the concrete electrical resistance and the ability of concrete to resist chloride ingress and/or oxygen penetration resulting in prolonging the onset of corrosion. After depassivation it may slow down the corrosion rate of the steel bar. This indicates the need for further study of the effect of electric arc furnace dust (EAFD) addition on the concrete resistivity. In this study, concrete specimens rather than mortars were cast with different additions of EAFD to verify the electrochemical results obtained and to try to understand the role of EAFD addition in influencing the corrosion behaviour of reinforcing steel bar embedded in concrete and its relation to the resistivity of concrete. The results of these investigations indicated that the corrosion resistance of steel bars embedded in concrete containing EAFD was improved, which may link to the high resistivity found in EAFD-concrete. In this paper, potential measurements, corrosion rates, gravimetric corrosion weight results and resistivity measurements will be presented and their relationships will also be discussed in details.

Bend Resistance of Polymer Cement Slurry Coated Reinforcing bars (폴리머 시멘트 슬러리 도장철근의 내굴곡성)

  • 김현기;김민호;장성주;김완기;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.1017-1022
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    • 2001
  • The bend resistance of coated reinforcing bar is greatly influenced by adhesion strength of bar and coating materials and transformation of coating materials to the bar. Expecially, tearing state or a limited microscopic cracks are predicted on the inside and outside of bending angle because of adhesion strength and elongation is very different with types of polymer materials using bar coating, and these parts are accelerated corrosion as penetration of bar corrosion effects factor. In this study, cement modified polymer are prepared four types and differ from polymer cement ratio of 50% and 100%, coating thickness of 250$\mu$m and 450$\mu$m, coating number, curing age of 3, 7, 14 and 280days, and then tested bend resistance as bending angle $90^{\circ}$, $135^{\circ}$ and $180^{\circ}$ for observe the microscopic demage effect according as bar bend. From the test results, when is used cement modified polymer as coating materials of bar, St/BA is showed excellent bend resistance than a polyacrylic emulsion and SBR because of softness. But it is to need attention because as coating parts are pressed down and tearing, also experimental study is proceeded to corrosion potential on the inside and outside of coated reinforcing bar.

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Influence of Loading on the Corrosion of Reinforcing Bar (철근콘크리트 보의 철근부식에 미치는 하중의 영향에 관한 연구)

  • 김형래;윤상천;지남용
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.171-179
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    • 1999
  • The present research investigated the interaction among loading level, corrosion rate and flexural deflection of reinforced concrete beams. 10cm$\times$15cm$\times$110cm reinforced concrete beams were prepared and subjected to different levels of flexural loading, including 0%, 45% and 75% of the ultimate load. The beams with either a pre-load or a sustained load were also exposed to a laboratory environment with ponding and wetting/drying cycling at room temperature. Half cell potential and galvanized current measurements were taken to monitor corrosion process of reinforcing steel. After corrosion initiation, external current was applied to some of the beams to accelerate corrosion propagation. The beam deflections were recorded during the entire tests. The results indicate that loading level has significant effect on corrosion rate. The beams under a sustained load had much higher corrosion rate than the pre-loaded and then unloaded beams. Significant corrosion may result in an increase in beam deflection and affect serviceability of the structure. The present research may provide an insight into structural condition evaluation and service life predictions of reinforced concrete.

Optimal Design of the PSC Beam Reinforcement for Minimum Life-Cycle Cost (최소생애주기비용을 위한 PSC보 보강의 최적설계)

  • Bang, Myung-Seok;Han, Sung-Ho
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.125-130
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    • 2008
  • To optimize the selected reinforcing method for application to PSC Beam bridges, the reliability analysis was performed with consideration for the increase and decrease of the member section based on the standard design section, and the minimum life-cycle cost(LCC) was calculated from this analysis with consideration for the aleatory uncertainty. Moreover, the mean, 50%, 75%, and 90% distributions of the analysis results were re-evaluated quantitatively by considering the effect of the epistemic uncertainty. The reliability results gained from the application of the reinforcing method, as well as the optimal design method based on the minimum LCC, will provide more reasonable design criteria for the PSC Beam bridges.

potential of Noncircular Fiber as Reinforcing Material l. C-type carbon fiber

  • Boh, Shim-Hwan;Rhee Bo sung
    • Korean Journal of Materials Research
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    • v.4 no.7
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    • pp.817-822
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    • 1994
  • The reinforcing effect of C-shape carbon fiber was investigated as comparing to typical round-shape fiber with similar properties. The results show that C-shape fiber reinforced materials have better in almost all aspects of mechanical properties, or 218% in flexural strength, 223% flexural modulus, 157% interlamina shear strength, 227% impact strength, 184% transverse flexural strength and so on. Also in damping characteristics considerably concerned with fatigue life, friction/wear coefficient of a material, C-CF/EP had about 185% greater. In this research, we present the potential of non-circular fiber reinforcing materials by C-shape carbon fiber.

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