• Title/Summary/Keyword: Shell body

Search Result 323, Processing Time 0.031 seconds

The Potential Energy Surfaces and Dipole Moment Functions of $NH_2$ by ab initio Effective Valence Shell Hamiltonian

  • 윤승훈;윤영속;박종근;선호성
    • Bulletin of the Korean Chemical Society
    • /
    • v.19 no.9
    • /
    • pp.985-993
    • /
    • 1998
  • The second order effective valence shell Hamiltonian ($H^v$), which is based on quasidegencrate many-body perturbation theory, is applied to determining the potential energy surfaces and the dipole moment functions of the various valence states of $NH_2$. The $H^v$ calculated values are found to be in good agreement with those of other ab initio calculations or experiments. It signifies the fact that the $H^v$ is a good ab initio method to describe the energies and properties of various valence states with a same chemical accuracy. Furthermore, it is shown that the lowest (second order for energy and the first order for property) order $H^v$ method is very accurate for small molecules like $NH_2$ and the matrix elements of Hv which are computed only once are all we need to accurately describe all the valence states simultaneously.

Vibration Analysis of High-Speed EMU Car Body Using Equivalent Stiffness and Shell Element (등가강성과 Shell 요소를 이용한 분산형 고속전철의 차체 진동 해석)

  • Baek, Seung-Guk;Shin, Bum-Sik;Choi, Jin-Hwan;Lee, Sang-Won;Choi, Yeon-Sun;Koo, Ja-Choon
    • Proceedings of the KSR Conference
    • /
    • 2009.05b
    • /
    • pp.217-222
    • /
    • 2009
  • High-speed EMU under development vibrates more than a articulated high-speed train since power units are attached on each vehicle and railway vehicle. In this study, anisotropic equivalent stiffness of a aluminum extrusion plate were calculated to know and predict vibration characteristic of High-speed EMU under development. Eigen frequencies and modal shape of high speed train vehicle were calculated. And vibration generated was predicted at each position of vehicle when vehicle was operating.

  • PDF

Interaction of Fluid and Thin Shell Structure with Signed Distance Fields (거리 장 함수를 이용한 얇은 막과 유체의 예측 기반 상호작용 시뮬레이션)

  • Kim, Po-Ram;Shin, Seung-Ho;Lim, Jae-Ho;Kim, Chang-Hun
    • Journal of the Korea Computer Graphics Society
    • /
    • v.17 no.1
    • /
    • pp.17-24
    • /
    • 2011
  • In Computer Graphics, interaction between a particle-based fluid and a rigid body is important. In General, this interaction has been simulated in a discrete environment. As a result, there have been lots of errors. The larger the time step is used, the bigger the error is. This paper describes how to minimize the error in a discrete environment. To be specific, the collision handling method is that estimates particle collision using a signed distance function increases continuously according to space. At the time a fluid particle and a rigid body model collide, the exact collision time and the position is estimated. Through this, we propose the method how to be simulated the interaction between a fluid and a rigid body model as a continuous environment.

An Ergonomic Study on the Function of the Basic Pattern of Clothing -On the Expansion and Contraction of the Skin Surface of the Upper Body- (의복 원형의 기능성에 관한 인간공학적 연구)

  • 함옥상
    • Journal of the Korean Home Economics Association
    • /
    • v.17 no.4
    • /
    • pp.1-14
    • /
    • 1979
  • The functional problems of the basic pattern of clothing are a matter of the first importance to clothing construction. Therefore, the ergonomic analysis of the expansion and contraction of the upper body surface, due to motion, has become required. thus in order to obtain the measurements and rate of expansion and contraction of the upper body surface following from its motions, the development figure of " Shell" and somatometry were employed. The results obtained through the investigation can be summarized as follows : 1) According to the developmental figures of "Shell" the latitudes centering around the shoulder line present contractive tendencies by arm movement. The longitudes around the center back waist length are expansive tendencies when bent forward. In the case of a 15$^{\circ}$ lean backward posture, the longitudes around the center front waist length are expansive tendencies. 2) By somatometry, the region from the scapula to the axilla point the upper back with presents the greatest expansion (more than 30%). The region from scapla to arm presents the maximum rate of contraction. In considering the longitude , under the axilla waist length and the bust point waist length generally shows the greatest rate of expansion. 3) The bust point waist length and under the axilla waist length are of great importance to the basic pattern of clothing. and have expansive tendencies(6.3cm). Among the latitudes, the upper back width has the greatest tendency for expansion (7.83 cm). 4) The region which presents the greatest rate of the expansion and contraction is in the proximity of the arm. These results testify that the amount of room of the back width must be given consideration in constructing the basic pattern of clothing.pattern of clothing.

  • PDF

Analysis of diversity of hemolytic microbiome from aquafarm of arkshell, Scapharca broughtonii (피조개 양식장 내 용혈성 미생물의 다양성 분석)

  • Gwon, Byeong-Geun;Kim, Young-Ok;Nam, Bo-Hye;Kim, Woo-Jin;Kong, Hee Jeong;Kim, Bong-Seok;Jee, Young-Ju;Lee, Sang-Jun;An, Cheul Min;Kim, Dong-Gyun
    • Journal of fish pathology
    • /
    • v.26 no.3
    • /
    • pp.193-206
    • /
    • 2013
  • The ark shell, Scapharca broughtonii is a marine bivalve mollusks belonging to the family Arcidae and important seafood for Korean and Japanese, and southern coast is brisk bays for the ark shell aquaculture. However, productivity of ark shell from these regions were rapidly reduced during the last decade due to mass mortality. The reason of this great damage has not yet been identified. To overcome this economic loss, diverse investigations were focused on environmental factors that affects in the physiology of S. broughtonii, but microbiological researches were performed insufficiently. Hemoglobin is one of the major blood component of ark shell and is damaged by some species of bacterial toxins. We concentrated on this red pigment because hemolysis could be the cause of ark shell mortality. In this study, we analyzed microbial diversity of underwater sediments in coastal regions and also existences in the body of S. broughtonii. We investigate about 4,200 isolates collected from June to September for microbial diversity of sediments and ark shell. We screened all of culturable microorganisms, and identified 25 genera 118 species, 24 genera 89 species, 30 genera 109 species and 39 genera 141 species, and selected 140 unique colonies for identification and challenge assay.

The Role of Magnesium and Calcium in Eggshell Formation in Tsaiya Ducks and Leghorn Hens

  • Shen, T.F.;Chen, W.L.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.16 no.2
    • /
    • pp.290-296
    • /
    • 2003
  • Tsaiya ducks and Leghorn hens are the two major laying birds raised in Taiwan. They are all excellent egg layers. Tsaiya ducks are small in body size (1.3 kg) with bigger egg weight (65 g) and stronger eggshell breaking strength than eggs from hens. The eggshell consists mainly of calcium carbonate, hence calcium plays an important role in the eggshell formation. Magnesium is also present in eggshell in small amounts, which may have effect on maintaining eggshell quality. In comparison studies, it was shown that the duck eggshells contained higher calcium and lower magnesium content than chicken eggshells. The eggshell magnesium content was not affected by the dietary magnesium levels (690-2380 ppm) in ducks, but in hens, it increased linearly with dietary magnesium levels. The palisade layer ($5000{\times}$) of the eggshell was found to have a compact form for ducks while there are many hallow vesicles in chicken eggshells. The eggshell magnesium deposition model is different for ducks and hens with ducks having a one-peak and hens having a two-peak model. The calcium deposition model is similar for both birds. Both the carbonic anhydrase specific activity and total activity in the shell gland mucosa of ducks are higher than those in hens. Ducks retain higher magnesium and lower calcium in the shell gland mucosa and secret less magnesium and more calcium into the shell gland lumen for eggshell deposition. The ATPase specific activity is maintained fairly constant during the eggshell forming stage, indicating continuous calcium transport into the shell gland lumen for eggshell formation. The magnesium content in duck eggshells is much lower than that in hens indicating that the magnesium content in the eggshell may have an effect on eggshell quality.

Effect of Dietary Sodium Nitrate Consumption on Egg Production, Egg Quality Characteristics and Some Blood Indices in Native Hens of West Azarbaijan Province

  • Safary, H.;Daneshyar, Mohsen
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.11
    • /
    • pp.1611-1616
    • /
    • 2012
  • The aim of the study was to evaluate the effect of sodium nitrate consumption on egg quality and quantity, and some blood parameters of native breeder hens of West Azerbaijan province. One hundred native hens were used from wk 25 to 32 of age. These birds were divided into two groups. One group was fed the control diet (CD) but the other fed the same diet supplemented with 4.2 g/kg sodium nitrate (ND). After 2 wks of adaptation, eggs were collected daily and egg mass and egg production were measured weekly for five weeks. To assess the egg quality parameters, two eggs from each replicate pen were collected for three consecutive days each week. At the end of experimental period (wk 32 of age), blood samples of 5 birds per replicate were collected from the wing vein into anticoagulant tubes. Dietary sodium nitrate didn't affect the egg production, shell stiffness, shell thickness and Haugh unit (p>0.05) but it decreased the both egg production and egg mass during the last three weeks (wks 30, 31 and 32) (p<0.05). Furthermore, a treatment effect was observed for yolk colour (p<0.05). Both the egg production and egg mass were increased over time (p<0.05). No significant treatment${\times}$time interaction was observed for egg weight, egg production and egg mass (p>0.05). No effect of time or treatment${\times}$time were observed for shell stiffness (p>0.05). Over time, shell thickness was decreased while Haugh unit increased (p<0.05). None of the blood TP and TG or the activity of ALT, AST and LDH enzymes were affected by dietary consumption of sodium nitrate at wk 32 of age (p>0.05). Sodium nitrite decreased both the TAC and TC at wk 32 of age (p<0.001). It was concluded that the lower body antioxidant capacity of nitrate fed birds resulted in the lower performance (egg weight, egg production and egg mass).

An Experimental Study of Aerodynamic Characteristics on a Projectile with Counter-Rotating Head Installed Fins (조종면이 장착된 회전하는 발사체에서의 공력특성 분석에 관한 실험적 연구)

  • Park, Young-Ha;Je, Sang-Eon;Cho, Soo-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.41 no.5
    • /
    • pp.357-365
    • /
    • 2013
  • In this study, forces and moments were measured on a projectile which consisted of a missile configuration body(shell) and a head installed control fins. The shell and the head were separated each other and the shell was rotated by an electric motor. The head rotated reversely against the rotational direction of the shell. The rotational force on the head was obtained from a couple of fixed fins of which angular displacement were set to the rotational direction equally. The air velocity was 40m/s on the experiment and the Reynolds number based on the diameter of head was $1.3{\times}10^5$. The other couple of fins were used to control the position and direction of the projectile by changing the angular displacement. From this experiment, the variation of force and moment were measured on the rotating projectile, and the effective amplitude and frequency were obtained through the FFT analysis.

Topology Optimization for Radiation and Scattering of Sound from a Thin-body (박판 구조물의 소음 방사 및 산란에 대한 위상 최적 설계)

  • 이제원;왕세명
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.05a
    • /
    • pp.1032-1037
    • /
    • 2003
  • Although the holes on the shell case are very important fer the acoustic performance, it is difficult to solve the problem because the case includes thin bodies. Hence, in the past, only the method of trial and error, which depends on the engineer's intuition and experience, was available fur the design of holes. Many researchers have tried to solve the thin-body acoustic problems, since the conventional boundary element method (BEM ) using the Helmholtz integral equation fails to yield a reliable solution fer the numerical modelling of radiation anti scattering of sound from thin bodies. In the area of the analysis of thin-body acoustic problem, three approaches are generally used; the multi-domain BEM, the indirect variational BEM, and the normal derivative integral equation And there has been just a f9w study reported on the design optimization for the acoustic radiation problems by using only the conventional BEM. For the thin-body acoustics, however, no further study in the optimization fields has been reported. In this research, the normal derivative integral equation is adopted as an analysis formulation in the thin-body acoustics, and then used fur the optimization. The analytical approaches for the design of holes are proposed by using a topology optimization technique and a genetic algorithm. The proposed approaches are implemented and validated using numerical examples.

  • PDF

The Effect of Growth and Survival Rate on Feeding Rate of Abalone, Haliotis discus hannai, Rearing in Net Cage Culture or Indoor Tank Culture (해상가두리 및 실내 육상수조에서 먹이 공급비율에 따른 북방전복, Haliotis discus hannai의 성장 및 생존율)

  • Kim, Byeong-Hak;Park, Min-Woo;Kim, Tae-Ik;Son, Maeng-Hyun;Lee, Si-Woo
    • The Korean Journal of Malacology
    • /
    • v.30 no.3
    • /
    • pp.227-234
    • /
    • 2014
  • The effect of different feeding rate on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage culture and indoor tank culture. Feeding rate is determined that was fed 5, 10, 15 and 20 percentage to abalone at body weight once daily : 5 daily feeding rate (DFR), 10DFR, 15DFR and 20DFR. After that, it was conducted to reared during thirteen month with two replicates in net-cage culture and indoor tank culture. In the growth performance of reared abalone (initial mean shell length $54.18{\pm}7.39mm$) in net cage culture, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth, as well as weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight of 20DFR were lower than those of different groups (P < 0.05). Also, survival rates of 20DFR was lower than those of different groups (P < 0.05). In the growth performance of reared abalone (initial mean shell length $49.70{\pm}2.28mm$) in indoor tank culture, that the ARG, DGR and SGR to the shell length and shell breadth, as well as WG, DWG and SWG to body weight of 5DFR and 10DFR were lower than those of different groups (P < 0.05). And also, survival rates of 20DFR was lower than those of different groups (P < 0.05). Therefore, these results is showed that the daily feeding rate for natural feed in net-cage culture and indoor tank culture should be to supply among 5-10 percents, taking into account growth, survival rate and economical efficiency.