• Title/Summary/Keyword: Strength of bone

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Effects of Dietary Energy and Protein Levels on Growth of Egg Breeder Pullets (산란종계 육성기 사료의 에너지 및 단백질 수준이 성장에 미치는 영향)

  • 노성래;유선종;김성권;김은집;안병기;강창원
    • Korean Journal of Poultry Science
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    • v.30 no.2
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    • pp.73-81
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    • 2003
  • This experiment was conducted to investigate the effects of dietary energy and protein levels on the growth rate of egg breeder pullets. A total of 360 Hy-Line Brown pullets aged 2 to 6 weeks (Phase I) were fed 5 rations differing in dietary protein (17, 19 and 20%) and energy (2,800, 2,950 and 3,050 kcal/kg, TMEn) leveIs for a period of 5 weeks and those aged 6 to 10 weeks (Phase II) were fed 5 rations differing in dietary protein (15, 16 and 17%) and energy (2,800, 2,900 and 3,000 kcal/kg, TMEn) levels in order to evaluate the optimum dietary energy and protein leveIs for egg breeder pullets reared in cages. Their body weight gains were significantly influenced by the dietary protein levels (P<0.05). The dietary energy levels did not greatly affect the growth performances throughout the experimental period. The low energy and protein regimen based on NRC requirement (control) was found to produce smaller pullets and lower tibia bone measurements as compared to the higher regimen groups. With the increase in dietary energy and protein levels, tibial bone strength and ash content also gradually increased (P<0.05). There were no significant differences in the flock uniformity among the treatments. These results indicate that increases in dietary energy and protein levels above the NRC requirements appeared to be more effective in obtaining the optimal growth and bone developments of egg breeder pullets reared in cage.

Mechanical and Biological Characteristics of Reinforced 3D Printing Filament Composites with Agricultural By-product

  • Kim, Hye-Been;Seo, Yu-Ri;Chang, Kyeong-Je;Park, Sang-Bae;Seonwoo, Hoon;Kim, Jin-Woo;Kim, Jangho;Lim, Ki-Taek
    • Food Engineering Progress
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    • v.21 no.3
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    • pp.233-241
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    • 2017
  • Scaffolds of cell substrates are biophysical platforms for cell attachment, proliferation, and differentiation. They ultimately play a leading-edge role in the regeneration of tissues. Recent studies have shown the potential of bioactive scaffolds (i.e., osteo-inductive) through 3D printing. In this study, rice bran-derived biocomposite was fabricated for fused deposition modeling (FDM)-based 3D printing as a potential bone-graft analogue. Rice bran by-product was blended with poly caprolactone (PCL), a synthetic commercial biodegradable polymer. An extruder with extrusion process molding was adopted to manufacture the newly blended "green material." Processing conditions affected the performance of these blends. Bio-filament composite was characterized using field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical characterization of bio-filament composite was carried out to determine stress-strain and compressive strength. Biological behaviors of bio-filament composites were also investigated by assessing cell cytotoxicity and water contact angle. EDX results of bio-filament composites indicated the presence of organic compounds. These bio-filament composites were found to have higher tensile strength than conventional PCL filament. They exhibited positive response in cytotoxicity. Biological analysis revealed better compatibility of r-PCL with rice bran. Such rice bran blended bio-filament composite was found to have higher elongation and strength compared to control PCL.

A Research on the Physique Reformation of the Player Character Depending on the Character Status in MMORPG (캐릭터 스테이터스에 따른 플레이어 캐릭터 외형 변화 연구 -MMORPG를 중심으로-)

  • Kih, Tae-Suk;Baek, Hyoung-Mok;Chang, Jun-O;Rhee, Dae-Woong
    • Journal of Korea Game Society
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    • v.9 no.6
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    • pp.21-30
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    • 2009
  • In this paper, we have proposed to show the change of player character's status visually in character graphics. We have chosen strength and dexterity as basic character status out of strength, constitution, willness, intelligence, and dexterity to express the transition of character graphics. The length of each bone can be reflecting the numerical value of dexterity, and the thickness can show that of strength. This kind of visual representation of character status helps player to reveal his/her character identity. We are expecting this visual representation for direction of fostering characters and character's experience would be applied to various entertainment areas widely.

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Effects of Dietary Vitamins C and E on Egg Shell Quality of Broiler Breeder Hens Exposed to Heat Stress

  • Chung, M.K.;Choi, J.H.;Chung, Y.K.;Chee, K.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.4
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    • pp.545-551
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    • 2005
  • A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.

The Investigation on Bond characteristics of Reinforced Concrete (철근콘크리트의 부착특성에 관한 연구)

  • 신성우;최종수;이광수
    • Magazine of the Korea Concrete Institute
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    • v.7 no.1
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    • pp.117-125
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    • 1995
  • Bond test was carried out to assess the effect of several variables on bond characteristics between reinforcing bar and concrete. Key variables are concrete compressive strength($f_c$'=340, 460, 6513, 904kg/$cm^2$), concrete cover (25, 38, 51, 105, IlOmm), and bar diameter(Dl3 and D22). Confining effect and bar spacing are not taken into account. Thirty-two specimens subjected to uniaxial tension were tested under hypothesis uniform bond stress distribution along the reinforcing bar embeded in concrete. Failure mode was examined and local bond stress versus slip relationship diagrams were represented to show effect of the above variables, also test results(u1timate bond stress) were compared with bond and development provisions of the ACI Building Code(AC1 318-89) and proposed equations from previous research. According to analysis, borld stress and ultimate bond stress increased although compressive strength increased beyond the ACI Building Code upper limit. Therefore in calculating development length. compressive strength effect(exceeding 700kg /$cm^2$) should be accounted.

A STUDY ON BONE STRENGTH AND THE DEGREE OF CONVERSION OF DENTIN BONDING AGENTS (수종 상아질 접착제의 결합강도와 중합률에 관한 연구)

  • Kim, Byung-Hyun;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.23 no.1
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    • pp.68-93
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    • 1998
  • The physical properties of polymer are greatly influenced by the extent to which a resin cures. The presence of un reacted monomer can, have a plasticizing effect on the polymer, thereby altering the physical and mechanical properties of dentin bonding agent (DBA). If the DBA does not polymerize sufficiently, it will leave a weak bonding layer and lead to lower bond strength. The purpose of this study was to evaluate the shear bond strengths(SBS) and the degree of conversion (DC) of 4 commercialy avilable dentin bonding systems which are composed of 2 multi-bottle systems [Scotchbond Multi-Purpose (SMP), AeliteBond(AB)] and 2 onebottle systems [SingleBond(SB), One-Step(OS)]. For shear bond strength measurement, labial surfaces of freshly extracted bovine incisors were ground with # 600 grit SiC paper to expose dentin. Four different groups of samples were formed, with 10 samples. being made for each of the 4 commercial DBA in each group according to the curing sequences of DBA and overlayer thickness of composites: Group I (standard cure and 1mm thick composites) : The DBA was light cured and the composites of 1mm thickness was applied ; Group II (standard cure and 2mm thick composites) : The DBA was light cured and the composites of 2mm thickness was applied; Group III (simultaneous cure and 1mm thick composites) : The DBA was not light-cured and simultaneously cured with composites of 1mm thickness; Group N (simultaneous cure and 2mm thick composites) : The DBA was. not light-cured and simultaneously cured with composites of 2mm thickness. The SBS was measured immediately after the composites was bonded to the bovine dentin using an Instron machine. The DC of the DBA was examined in a thin film under simulated conditions of the experimental groups according to the curing sequences and overlayer thickness of composites in the SBS test. using a Fourier transform Infrared(FTIR) spectrometer. The following results were obtained from SBS tests and DC measurements 1. In SBS tests, the multi-bottle DBA(SMP, AB) had a generally higher bond strength values than the one bottle DBA(SB, OS). In DC measurements, the one bottle DBA(SB, OS) had a significantly higher DC than the multi-bottle DBA(SMP, AB). 2. In all DBAs except OS, there was no significant difference between the bond strength of group I (standard cure and 1mm thick composites) and that of group III (simultaneous cure and 1mm thick composites). SMP, SB in Group I had a significantly higher DC than those in group III, but AB, OS in group I had a significantly lower DC than those in group III 3. All DBAs in Goup II (standard cure and 2mm thick composites) had significantly higher bond strength and DC than those in Group N (simultaneous cure and 2mm thick composites). 4. In all DBAs, there was no significantly different SBS and DC between Group I and Group II, but all DBAs in Group III had significantly higher SBS and DC than those in Group IV.

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A Review of Structure and Biomechanics of the Skeletal Muscle (골격근의 구조와 생역학에 관한 고찰)

  • Gong, Won-Tae
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.13 no.1
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    • pp.58-66
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    • 2007
  • The purpose of this study is to understand the structure and biomechanics of the skeletal muscle. The skeletal muscle takes 40 to 45% of the whole body. Stable posture requires a balance of muscle. However, when the muscle strength is unbalanced, movement initiates. The power generated by the muscle is a primary means to adjust the equilibrium of posture and movement. The structural unit of the skeletal muscle is a long cylindrical type muscle fiber which contains hundreds of nucleus. The thickness of muscle fiber is about $10-100{\mu}m$, and its length is about 1-50cm. Muscle fiber is composed of myofibril that is covered with plasma membrane which is called sarcolemma. In understanding the movement of human body, it is important to comprehend the movement of bone and joint and the tension of muscle. Understanding the structure and biomechanics of muscle also provides basic information on clinical treatment of patients.

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Preparation of Dense Polycrystalline Hydroxyapatite Ceramics for the Application of Tooth Implants (인공치아용 수산화 인산칼슘 요업체의 제조)

  • 하조웅;정형진
    • Journal of the Korean Ceramic Society
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    • v.20 no.1
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    • pp.55-62
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    • 1983
  • the preliminary work on the prepartion of fine hydroxyapatite powder and the synthesis of dense hydroxyapatite ceramic from the powder were investigated for the development of artificial bone and tooth materials for implants. The effects of the process variables such as compositions of the raw materials the initial pH of the solutions and sintering temperature on the physical properties were investigated in order to determine the optimum conditions for the fabrication of tooth implant material. As the initial pH of the solutions was increased in the range of 10-11.6 the initial particle size of precipitates was decreased thus the sinterability of precipitates was improved. It was found that the composition of calcium rich of 1.75 in Ca/P mole ratio exhibited better sinterability and mechanical strength of the apatite ceramics for example the highest value of Vicker's hardness obtained from the compositions of 1.75 in Ca/P mole ratio was 764±30 Kg/mm2 compared to the maximum value of 600 kg/mm2 obtained from the compositions of 1.67 in Ca/P mole ratio.

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Physiological Changes with Aging (노화(Aging)에 따른 생리학적 변화)

  • Kim Suhn-Yeop;Yi Seung-Ju
    • The Journal of Korean Physical Therapy
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    • v.5 no.1
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    • pp.79-87
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    • 1993
  • The purpose of this literature review was to identify the physiological changes with aging. The results of this renew were to follows : We have seen a wide variety of such changes in the cells and in all organ systems. 1. At least 40 percent of people over 65 will die of cardiac disease, 15 percent of cerebrovascular disease, and possibly another 5 percent of other types of vascular impairment. 2. The increase rigidity of the thoracic wall and the decreased strength of the expiratory muscles decrease the propulsive effectiveness of the cough. 3. The density of capillaries per motor units is decreased. 4. Starting before age 40 in both sexes there is a shift from an increase in bone mass to a progressive decrease. 5. Histologic studies show a lim age-correlated decrease in the number of Pacini's. Merkel's, and Meissner's corpuscles.

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Sports Injury of the Elbow (주관절의 스포츠 손상)

  • Sin, Hyeon-Dae
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.7 no.1
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    • pp.8-14
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    • 2008
  • Elbow joint injuries during exercise mostly occur by repeated stress to the joint than direct trauma. A pitcher who uses his arm above his head is most likely to be injured. So learning the right way to exercise and gaining the strength by maturating the body are essential for diminishing the chance of injury. On lateral ulnar tendon injury, which is most commonly injured area on elbow joint, pitchers generally complain of pain in arm movement above head and reduction of velocity, accuracy, and number of pitching. When there is pain on upper arm in harsh using, the stress fracture must be thought and epicondylar physis fracture of medial arm can occur by repeated abduction stress and contraction of flexors on forearm on children with immature skeleton. Osteochondritis dissecans of capitullum occur in young athletes who use there upper limb continuously lifting weights and gym work. And stress of abduction-extension includes damage of soft tissue and bone components, post medial crush syndrome, lateral ulnar ligament injury, extensor-abductor injury, stress of radius- capitullum are in this category.

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