• Title/Summary/Keyword: physical properties

Search Result 10,066, Processing Time 0.037 seconds

Post-buckling analysis of Timoshenko beams with temperature-dependent physical properties under uniform thermal loading

  • Akbas, Seref Doguscan;Kocaturk, Turgut
    • Structural Engineering and Mechanics
    • /
    • v.44 no.1
    • /
    • pp.109-125
    • /
    • 2012
  • Post-buckling behavior of Timoshenko beams subjected to uniform temperature rising with temperature dependent physical properties are studied in this paper by using the total Lagrangian Timoshenko beam element approximation. The beam is clamped at both ends. In the case of beams with immovable ends, temperature rise causes compressible forces end therefore buckling and post-buckling phenomena occurs. It is known that post-buckling problems are geometrically nonlinear problems. Also, the material properties (Young's modulus, coefficient of thermal expansion, yield stress) are temperature dependent: That is the coefficients of the governing equations are not constant in this study. This situation suggests the physical nonlinearity of the problem. Hence, the considered problem is both geometrically and physically nonlinear. The considered highly non-linear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The beams considered in numerical examples are made of Austenitic Stainless Steel (316). The convergence studies are made. In this study, the difference between temperature dependent and independent physical properties are investigated in detail in post-buckling case. The relationships between deflections, thermal post-buckling configuration, critical buckling temperature, maximum stresses of the beams and temperature rising are illustrated in detail in post-buckling case.

Effect of Cyclic Change of Wet Bulb Temperature During Yellowing Stage on Physical Properties of Flue-Cured Tobacco (황색종 연초 황변기 cyclic건조가 건조엽의 물리성에 미치는 영향)

  • Lee, Chul-Hwan;Jin, Jeong-Eui;Han, Chul-Soo
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.20 no.1
    • /
    • pp.13-18
    • /
    • 1998
  • In the flue curing process, the wet bulb temperature is usually controlled at a constant level. To improve the quality of flue cured leaves, we studied the effect of the cyclic change of wet bulb temperature at the yellowing stage of flue curing on physical properties of cured leaves. The wet bulb temperature was automatically controlled between preset high (38℃) and low point (35℃) every one hour cyclically. As a result, the acceleration of the increase in the physical properties of cured leaves were observed. The leaves cured by this method were more or less orange in color, better bodied, and less brittle compared with the leaves produced by conventional curing. However, the leaves cured by this method had a little sharpness and harshness. As to the physical properties, there was decreased in occurrence of flat leaves than that of conventional ones. On the other hand, in case of cyclic curing method, increase of price per kg reached to 2-3% compared with those of conventional ones.

  • PDF

Prediction Models for Fabric Color Emotion Factors by Visual Texture Characteristics and Physical Color Properties (직물의 시각적 질감특성과 물리적 색채성질에 의한 색채감성요인 예측모델)

  • Lee, An-Rye;Yi, Eun-Jou
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.9
    • /
    • pp.1567-1580
    • /
    • 2010
  • This study investigates the effects of visual texture on color emotion and establishes prediction models for color emotion by both physical color properties and visual texture characteristics. A variety of fabrics including silk, cotton, and flax were colored by digital textile printing according to chromatic hue and tone combinations that are evaluated in terms of color emotion. Subjective visual texture ratings are also obtained for gray-colored same fabrics to those used in color emotion tests. As a result, fabric clusters by visual texture factors showed significant differences in color emotion factors that are primarily affected by physical color properties. Finally prediction models for color emotion factors by both physical color properties and visual texture clusters were established, which has a potential to be used to explain color emotion according to the visual texture characteristics of fabrics.

Technical Trends of Domestic and Overseas on Electro-physical Properties Measurement (전기물성 측정의 국내외 기술 동향)

  • Park, Sam-Gyu;Cho, Seong-Jun;Lee, Tae-Jong;Lee, Seong-Kon;Lee, Sang-Kyu
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2007.06a
    • /
    • pp.285-290
    • /
    • 2007
  • Electrical and electromagnetic methods were widely applied to survey of civil engineering, environment site assessments and maintenance of underground structures in Korea. Electro-physical properties measurements of soil and rock are necessary in order to quantitatively estimate the ground from these survey results. A few geotechnical researcher groups have been simplified measurement system of the electro-physical properties, which was intermittently operating by the necessity. Recent strong concern about $CO_2$ underground storage and development of gas hydrate projects have urged many advanced countries. The electro-physical properties estimation of the deep object stratum is very importance for basic information of these research. So, advanced countries have a high-end measurement system with high temperature(200 degrees) and pressure(300 MPa), also they have been a lot of experience and know-how on the electro-physical properties measurement.

  • PDF

Studies on Physical and Sensory Properties of Premium Vanilla Ice Cream Distributed in Korean Market

  • Choi, Mi-Jung;Shin, Kwang-Soon
    • Food Science of Animal Resources
    • /
    • v.34 no.6
    • /
    • pp.757-762
    • /
    • 2014
  • The object of this study was to investigate the difference in physical and sensory properties of various premium ice creams. The physical properties of the various ice creams were compared by manufacturing brand. The water contents of the samples differed, with BR having the highest value at 60.5%, followed by NT and CS at 57.8% and 56.9%, respectively. The higher the water content, the lower Brix and milk fat contents in all samples. The density of the samples showed almost similar values in all samples (p>0.05). The viscosity of each ice cream had no effect on the water content in any of the brands. Before melting of the ice cream, the total color difference was dependent on the lightness, especially in the vanilla ice cream, owing to the reflection of light on the surface of the ice crystals. The CS product melted the fastest. In the sensory test, CS obtained a significantly higher sweetness intensity score but a lower score for color intensity, probably due to the smaller difference in total color, by which consumers might consider the color of CS as less intense. From this study, the cold chain system for ice cream distribution might be important to decide the physical properties although the concentration of milk fat is key factor in premium ice cream.

Physical Properties of the Hardened Loess Using Natural Binding Materials (천연 결합재를 사용한 황토경화체의 물성에 대한 연구)

  • Kim, Jin Seok;Oh, Young Hun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.16 no.4
    • /
    • pp.44-51
    • /
    • 2012
  • In this study, hardened loess bodies, which did not compose of cement or any chemical binder, were made and tested to evaluate the physical properties such as slump, air content, and compressive strength. Addition of a natural binding material to mixture of loess and lime showed better performance in physical properties. However a lime among natural binding materials is considered as a superior binder to improve the properties of the hardened bodies. According to the experimental results, mixing proportion with 45% of W/B ratio, $285kg/m^3$ of water content, and 60% lime substitution ratio was recommended to acquire the good performance of physical properties for the hardened loess bodies.

A Study on the Physical Properties of Silk Fabrics - Bending and Luster Properties - (견직물(絹織物)의 물리적(物理的) 특성(特性) 변화(變化)에 대(對)한 연구(硏究) - 굽힘 및 광택(光澤) 특성(特性)-)

  • Park, Shin-Jung;Kim, Jong-Jun;Jeon, Dong-Won
    • Journal of Fashion Business
    • /
    • v.8 no.5
    • /
    • pp.31-40
    • /
    • 2004
  • The purpose of this study is to investigate the change of the physical properties, bending and luster properties, which are related to the touch and appearance of silk fabrics modified by the degumming process. The silk has long been known as one of the most elegant and soft textile materials. The raw silk yarn, or cocoon bave, spun from the spinneret, is rather stiff due to the sericin covering the two fibroins together. The sericin can be removed during a degumming process. The removal of the sericin would result in remarkable change in the physical properties of the raw silk fabrics, including luster of the fabrics, which process parameters could possibly be utilized to adequately control the silk fabric properties. The KES(Kawabata Evaluation System) is a testing methodology that has been used with considerable success for predicting the hand and tailorability of apparel fabrics. This study uses one of the KES, bending tester, to measure the bending properties of the silk fabrics degummed for specified period to change the physical/mechanical properties of the fabric. The KES bending measurement revealed that the bending rigidity decreased for both the warp and weft direction of the silk fabrics with the increase of the degumming period. It has been shown in this study that the some of the hand-related physical properties, including the bending rigidity, drapability, and luster, could be modified with the change in the degumming period.

Wood Physical and Mechanical Properties of Clonal Teak (Tectona grandis) Stands Under Different Thinning and Pruning Intensity Levels Planted in Java, Indonesia

  • Gama Widya SETA;Fanny HIDAYATI;WIDIYATNO WIDIYATNO;Mohammad NA'IEM
    • Journal of the Korean Wood Science and Technology
    • /
    • v.51 no.2
    • /
    • pp.109-132
    • /
    • 2023
  • The objective of this study was to reveal the impact of thinning and pruning regimes on the physical and mechanical properties of clonal teak wood planted in Java. In this study, a 15-year-old clonal teak plantation was carried out and the obtained data were evaluated with analysis of variance (ANOVA). The results showed that different thinning intensities had a significant impact on the alteration of heartwood volume development (F = 25.63; p < 0.0001). Meanwhile, the impact of different thinning treatments in several physical properties depends on the pruning treatment levels [moisture content (F= 12.18, p < 0.0001); tangential shrinkage (F = 15.60, p < 0.0001); T/R ratio (F = 7.17, p < 0.0001); and volumetric shrinkage (F = 10.81, p < 0.0001)]. However, different thinning intensities had no significant impact on wood basic density alteration (F = 0.72, p = 0.486), while pruning intensities affect the differences between radial (F = 3.52, p = 0.030) and volumetric shrinkage (F = 3.13, p = 0.044). In mechanical properties, thinning intensity levels did not promote any significant differences [modulus of elasticity (F = 1.41, p = 0.248); modulus of rupture (F = 0.94, p = 0.392); compressive strength parallel to grain (F = 0.21, p = 0.813); and compressive strength perpendicular to the grain (F = 0.41, p = 0.669)]. Meanwhile, different pruning treatments and combination treatments were not significantly altered all mechanical properties. These results indicated that the thinning and pruning regimes can enhance the mechanical properties without having a serious alteration in the physical properties of clonal teak wood.

Effect of Bed Height on Ginseng Growth and Soil Physical Properties (인삼포 두둑높이가 인삼의 생육 및 토양물리성에 미치는 영향)

  • 이일호;박찬수
    • Journal of Ginseng Research
    • /
    • v.15 no.3
    • /
    • pp.197-199
    • /
    • 1991
  • Growth of ginseng and physical properties of soil were compared with bed height in experimental plots of sand loam for four year and clay loam soil for three year old ginseng plants, respectively. Field survey was also carried out to compare yield and soil physical properties with bed height in the same fold of six years old ginseng fields. High yield of ginseng root was observed at high bed both in the experimental plots and field survey as well. The rate of rusty root was significantly reduced at high bed. Soil porosity increased but soil hardness decreased at high bed.

  • PDF

Influences of Sodium Gluconate on the Physical Properties of Portland Cement Pastes and Mortars (포틀랜드 시멘트 페이스트 및 몰탈의 물성에 미치는 글루콘산 나트륨의 영향)

  • 김창은;이승헌;김원기;이경원
    • Journal of the Korean Ceramic Society
    • /
    • v.24 no.3
    • /
    • pp.289-295
    • /
    • 1987
  • The changes of physical properties of portland cement pastes and mortars were investigated by addition of sodium gluconate. Flow table experiment and viscosity measurement were took in order to find dispersing effect, and time-dependent changesof viscosity and rates of hydration heat evolution were carried out for the sake of finding retardation effect of hydration. And changes of physical properties of cement pastes and mortars were discussed by setting time, compressive strength and porosity.

  • PDF