• Title/Summary/Keyword: V-T curve

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Evaluation of Fracture Toughness and Constraint Effect of Cruciform Specimen under Biaxial Loading (이축하중을 받는 십자형 시편의 파괴인성 및 구속효과 평가)

  • Kim, Jong Min;Kim, Min Chul;Lee, Bong Sang
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.12 no.1
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    • pp.62-69
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    • 2016
  • Current guidance considers that uniaxially loaded specimen with a deep crack is used for the determination of the ductile-to-brittle transition temperature. However, reactor pressure vessel is under biaxial loading in real and the existence of deep crack is not probable through periodic in-service-inspection. The elastic stress intensity factor and the elastic-plastic J-integral which were used for crack-tip stress field and fracture mechanics assessment parameters. The difference of the loading condition and crack geometry can significantly influence on these parameters. Thus, a constraint effect caused by differences between standard specimens and a real structure can over/underestimate the fracture toughness, and it affects the results of the structural integrity assessment, consequentially. The present paper investigates the constraint effects by evaluating the master curve $T_0$ reference temperature of PCVN (Pre-cracked Charpy V-Notch) and small scale cruciform specimens which was designed to simulate biaxial loading condition with shallow crack through the fracture toughness tests and 3-dimensional elastic-plastic finite element analyses. Based on the finite element analysis results, the fracture toughness values of a small scale cruciform specimen were estimated, and the geometry-dependent factors of the cruciform specimen considered in the present study were determined. Finally, the transferability of the test results of these specimens was discussed.

Response to ACTH Challenge in Female Dairy Calves in Relation to Their Milk Yield

  • Szucs, E.;Febel, H.;Janbaz, J.;Huszenicza, Gy.;Mezes, M.;Tran, A.T.;Abraham, Cs.;Gaspardy, A.;Gyorkos, I.;Seenger, J.;Nasser, J.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.6
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    • pp.806-812
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    • 2003
  • Attempts have been made to establish relationship between the response to ACTH challenge in female calves, growth and first lactation performance. A total of 19 Holstein calves weighing 100 kg i. v. were given 0.50 IU of ACTH/kg $BW^{.75}$ (EXACTHIN inj., Richter G., Budapest) at 60 days of age. Serial blood samples were taken at times 0, 0.5, 1, 2, 3, 4 and 5 hours and analyzed for cortisol, glucose insulin and FFA levels. From challenge series the area under the curve from time of administration and the following 5 h were calculated. Negative, and mostly loose relationship between response to ACTH challenge for cortisol, insulin, or FFA and ADWG during growth have been established (p>0.05) with positive one for glucose. Bivariate coefficients of correlation varied within the range from -0.35 to 0.15. Estimations reveal negative correlation between the length of first lactation and cortisol or insulin (r=-0.80, p<0.001 and r=-0.45, p<0.10, resp.) Close association between cortisol or insulin and actual first lactation milk yield was found (r=-0.48, p<0.10; r=-0.64, p<0.01, resp.). Close relationship between the response to ACTH challenge and milk protein yield was present only for insulin (r=-0.59, p<0.05).

Age Structure and Biomass of the Icefish Pseudochaenichthys georgianus Norman (Channichthyidae) Between 1976 and 2009: a Possible Link to Climate Change

  • Traczyk, Ryszard;Meyer-Rochow, Victor Benno
    • Ocean and Polar Research
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    • v.41 no.4
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    • pp.233-250
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    • 2019
  • A re-assessment of the age structure of the population of the Antarctic icefish Pseudochaenichthys georgianus based on body length data covering the years 1976-2009 and including larvae and postlarvae collected in 1989 and 1990 allowed us to define age groups 0, I, and II as containing fish with respective body lengths of 6-9 cm, 15-27 cm and 27-39 cm. Age at maturity (first spawning) was found to occur in age group III at body lengths that have been falling from 50.1 cm in 1979 to 45.4 cm in 1992. Considering postlarvae together with adult fish, the v. Bertalanffy growth curve parameters were determined as L = 60.62 cm, k = 0.4, t0 = 0.25. Although the reasons for a maturity at shorter body lengths is not fully understood a host of environmental factors like increasing water temperatures and possibly changes in currents, interspecific competition, food availability, etc. are likely to be involved. Global warming (and not primarily overfishing) is likely to have been responsible for the disappearance of larger fish in the surface waters of South Georgia since 1977, for virtually all commercial fishing stopped in the early 1990s. On the other hand, the appearance of numerous younger spawning individuals suggests that larvae do survive in the colder deeper water below 200 m. The biomass of Ps. georgianus oscillates with a 4-year periodicity in contrast to that of the coexisting icefish Chaenocephalus aceratus: the former with a lower biomass in warm years and a higher one in cold years. The biomass of the third species of icefish in the region, i.e. Champsocephalus gunnari, also oscillates, but with a longer periodicity than that involved in the biology of the other two and its biomass increases in contrast to the other two species. The result is that the biomass all three species considered together is rather stable.

Women's Pant Pattern Design According to the Style Using 3D Body Scan Data (3차원 스캔 데이터를 활용한 스타일별 여성 팬츠 패턴 연구)

  • Yoon, Mi Kyung;Nam, Yun Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.1
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    • pp.97-113
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    • 2016
  • This study develops pant patterns using body shape, measurement and shell mesh data to decide optimal women's pants according to styles with excellent size, fit and shape for different individuals and silhouettes. Standard landmarks, lines, triangles and structures were set on a 3D scanned lower body shell to represent women in their twenties and flattened as a 2D pattern. Patterns were created and analyzed according to culotte, formal, slacks and tight type considering crotch shape, location of the crotch point, and adjusting waist darts. Flattened patterns were rotated to compare existing methods. The crease lines were then set through the hip protrusion point and compared. The main factor of the pant pattern were extracted, total rise, crotch depth, crotch width, angle of center line, shape of the center line curve, the thigh width, the amount of waist dart, and crease line position. With going tight style from the culotte, the fits are closer to the figure with minimized thigh circumference, the dart amount decreases, the crotch depth increases, the crotch extensions were shorter, and the angle of the center back increased. The total rise is U shape for culotte and is closer to V shape as the silhouette tightens. T-test of appearance evaluation of the developed pant pattern were conducted after analyzing measurements and shapes of each styles. The results of the developed patterns were superior to existing patterns in accordance to hip line between body and pants as well as appearance evaluation. We found systematic mechanisms among pattern factors that create various pant silhouettes. Evidence on classification of the silhouettes of traditional types of pants were explained objectively through the process of playing out 3D forms.

Biotransformation of Theophylline in Cirrhotic Rats Induced by Biliary Obstruction

  • Park, Eun-Jeon;Ko, Geon-Il;Kim, Jae-Baek;Sohn, Dong-Hwan
    • Archives of Pharmacal Research
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    • v.22 no.1
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    • pp.60-67
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    • 1999
  • The object of this work was to study the pharmacokinetic differences and the cause of these differences in cirrhotic rats induced by biliary obstruction when aminophylline (8 mg/kg as theophylline, i.v.) was administered. The concentrations of theophylline and its major metabolite (1,3-dimethyluric acid) in plasma were determined by HPLC. In addition, formation of 1,3-dimethyluric acid from theophylline in microsomes and the changes in the activity of drug metabolizing enzymes, which are suggested to be involved in theophylline metabolism, were determined. In cirrhotic rats, the systemic clearance of theophylline was reduced to 30% of the control value while AUC (area under the palsma concentration-tie curve) and (t1/2)$\beta$ were increased 1.3 fold and3.5 fold, respectively. The formation of 1,3-dimethyluric acid was decreased to 30% of the control value in microsomes of cirrhotic rat liver. In cirrhotic rat liver, activities of aniline hydroxylase (CYP2E1 related), erythromycin-N-demethylase (CYP3A related), and methoxyresorufin-O-demethylase (CYP1A2 related), which were reported to be related with theophyline metabolism, were decreased to 67%, 53%, and 76% that of normal rat liver, respectively. From the results, it can be concluded that in cirrhotic rats induced by biliary obstruction, the total body clearance of theophylline is markedly reduced and it may be due to decreased activity of drug metabolizing enzymes in liver.

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Liquid Crystal Alignment Effect and Electro-Optical Characteristics of TN-LCD on a-C:H Thin Films (a-C:H 박막을 이용한 액정 배향 효과 및 TN-LCD 의 전기광학 특성)

  • Hwang, Jeong-Yeon;Jo, Yong-Min;Rho, Soon-Jun;Baik, Hong-Koo;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.124-127
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    • 2002
  • LC aligning capabilities and the variation of pretilt angles with ion beam irradiation on the a-C:H thin films, and electro-optical (EO) performances of the ion beam aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the a-C:H thin film were studied. A high pretilt angle of $3.5{^{\circ}}$ via ion beam irradiation on the a-C:H thin film was measured. Also, the LC pretilt angle decreased due to the increase in surface roughness at over 2 min of IB exposure time. It is considered that this roughness increase due to increasing IB exposure time that generated destroy of oriented rings of atoms related to LC alignment. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the a-C:H thin film for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the a-C:H thin film for 1 min can be achieved. Finally, the residual DC property of the ion beam aligned TN-LCD with ion beam exposure of 1 min on the a-C:H thin film is almost same as that of the rubbing aligned TN-LCD on a PI surface.

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Modeling of the friction in the tool-workpiece system in diamond burnishing process

  • Maximov, J.T.;Anchev, A.P.;Duncheva, G.V.
    • Coupled systems mechanics
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    • v.4 no.4
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    • pp.279-295
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    • 2015
  • The article presents a theoretical-experimental approach developed for modeling the coefficient of sliding friction in the dynamic system tool-workpiece in slide diamond burnishing of low-alloy unhardened steels. The experimental setup, implemented on conventional lathe, includes a specially designed device, with a straight cantilever beam as body. The beam is simultaneously loaded by bending (from transverse slide friction force) and compression (from longitudinal burnishing force), which is a reason for geometrical nonlinearity. A method, based on the idea of separation of the variables (time and metric) before establishing the differential equation of motion, has been applied for dynamic modeling of the beam elastic curve. Between the longitudinal (burnishing force) and transverse (slide friction force) forces exists a correlation defined by Coulomb's law of sliding friction. On this basis, an analytical relationship between the beam deflection and the sought friction coefficient has been obtained. In order to measure the deflection of the beam, strain gauges connected in a "full bridge" type of circuit are used. A flexible adhesive is selected, which provides an opportunity for dynamic measurements through the constructed measuring system. The signal is proportional to the beam deflection and is fed to the analog input of USB DAQ board, from where the signal enters in a purposely created virtual instrument which is developed by means of Labview. The basic characteristic of the virtual instrument is the ability to record and visualize in a real time the measured deflection. The signal sampling frequency is chosen in accordance with Nyquist-Shannon sampling theorem. In order to obtain a regression model of the friction coefficient with the participation of the diamond burnishing process parameters, an experimental design with 55 experimental points is synthesized. A regression analysis and analysis of variance have been carried out. The influence of the factors on the friction coefficient is established using sections of the hyper-surface of the friction coefficient model with the hyper-planes.

Roadside Landslide and Ditch Erosion in Mountain Forest Road (산악지림도(山岳地林道)의 노견(路肩) 사면붕괴(斜面崩壞)와 측구침식(側溝浸蝕)에 관(關)한 연구(硏究))

  • Ma, Sang Kyu
    • Journal of Korean Society of Forest Science
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    • v.76 no.2
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    • pp.161-168
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    • 1987
  • Forest road (10 Km) constructed for the demonstrational purpose by Forest Work Training Center (F.T.C.) in 1984 was partly damaged through the roadside landside and ditch erosion by the typhoon in 1986. The causes were investigated to apply for protecting against the damage of mountain forest road. The damaging length caused by roadside landside is around 3% out of total length of 10 Km forest road, and mostly coming from the curve road filled up more than 10 m slope length on the concave mountain slope, partly from the foot of fillslope along the ever-following valley and from the both side of fillslope under the outlet of culvert with ever-flowing water. In case of ditch erosion, the big damage at V-type ditch is coming from the overflow of valley water flowing down along the inside slope. Other problem is also showing in the steepness of longitudial gradient, which is felt as a problem in road to be constructed under more than 10 persent of gradient. Other cause of ditch erosion is coming from the bury of sand basin (water collecting wall) by the debris in small diameter culvert zone, namely less than 400mm, in diameter and by the soil mass slumped down from steep wall slope. From above results the causes of F.T.C. model road damage is showing to come from no-following the general guide or little experience to protect against the forest road damage. When improved above mentioned mistakes, F.T.C. Method of mountain forest road type could be developed as a model of Mountain forest road.

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Saccharification of Foodwastes Using Cellulolytic and Amylolytic Enzymes from Trichoderma harzianum FJ1 and Its Kinetics

  • Kim Kyoung-Cheol;Kim Si-Wouk;Kim Myong-Jun;Kim Seong-Jun
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.1
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    • pp.52-59
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    • 2005
  • The study was targeted to saccharify foodwastes with the cellulolytic and amylolytic enzymes obtained from culture supernatant of Trichoderma harzianum FJ1 and analyze the kinetics of the saccharification in order to enlarge the utilization in industrial application. T. harzianum FJ1 highly produced various cellulolytic (filter paperase 0.9, carboxymethyl cellulase 22.0, ${\beta}$-glucosidase 1.2, Avicelase 0.4, xylanase 30.8, as U/mL-supernatant) and amylolytic (${alpha}$-amylase 5.6, ${\beta}$-amylase 3.1, glucoamylase 2.6, as U/mL-supernatant) enzymes. The $23{\sim}98\;g/L$ of reducing sugars were obtained under various experimental conditions by changing FPase to between $0.2{\sim}0.6\;U/mL$ and foodwastes between $5{\sim}20\%$ (w/v), with fixed conditions at $50^{\circ}C$, pH 5.0, and 100 rpm for 24 h. As the enzymatic hydrolysis of foodwastes were performed in a heterogeneous solid-liquid reaction system, it was significantly influenced by enzyme and substrate concentrations used, where the pH and temperature were fixed at their experimental optima of 5.0 and $50^{\circ}C$, respectively. An empirical model was employed to simplify the kinetics of the saccharification reaction. The reducing sugars concentration (X, g/L) in the saccharification reaction was expressed by a power curve ($X=K{\cdot}t^n$) for the reaction time (t), where the coefficient, K and n. were related to functions of the enzymes concentrations (E) and foodwastes concentrations (S), as follow: $K=10.894{\cdot}Ln(E{\cdot}S^2)-56.768,\;n=0.0608{\cdot}(E/S)^{-0.2130}$. The kinetic developed to analyze the effective saccharification of foodwastes composed of complex organic compounds could adequately explain the cases under various saccharification conditions. The kinetics results would be available for reducing sugars production processes, with the reducing sugars obtained at a lower cost can be used as carbon and energy sources in various fermentation industries.

Gas Exchanges and Dehydration in Different Intensities of Conditioning in Tifton 85 Bermudagrass: Nutritional Value during Hay Storage

  • Pasqualotto, M.;Neres, M.A.;Guimaraes, V.F.;Klein, J.;Inagaki, A.M.;Ducati, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.807-815
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    • 2015
  • The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.