A global unique solvability of entropic weak solution to the one-dimensional pressureless Euler system with a flocking dissipation

Ha, S.Y.,Huang, F.,Wang, Y. Academic Press 2014 Journal of differential equations Vol.257 No.5

We present a unique global solvability and flocking estimate of an entropic weak solution to the one-dimensional pressureless Euler system with a flocking dissipation in all-to-all coupling setting. This model appears naturally as a quasi-equilibrium model for hydrodynamic description of Cucker-Smale flocking. For the unique global solvability, we adopt the variation approach from Ding and Huang's work [19] on the inhomogeneous pressureless gas dynamic model. When initial mass and velocity are locally integrable and bounded measurable functions, respectively, we give explicit representations for the global entropic weak solutions. Our results do not require any smallness of initial data except that initial mass density is almost everywhere positive.

SEQUENCE ANALYSIS AND COMPARISON OF BOVINE α_S1-CASEIN GENOMIC DNA

Lin, C.S.,Huang, M.C.,Choo, K.B.,Tseng, Y.H. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.4

A phage clone containing the partial ${\alpha}_{S1}$-casein gene was isolated from a bovine genomic library by using mixed probes of ovine ${\alpha}_{S1}$-, ${\beta}$- and ${\kappa}$-casein cDNAs. Restriction enzyme mapping analysis for 14.6 kb revealed that the map was in conflict with the report of Meade et al. (1990), especially in the 3'-end fragment. Sequence analysis of 12.6 kb revealed a high AT/GC ratio (1.64); we have identified eight exon sequences according to the bovine ${\alpha}_{S1}$-casein cDNA sequence. The same exon/intron splice junction sequence was observed between these exons. We suggest that the bovine ${\alpha}_{S1}$-casein gene night contain a minimum of 18 exons and the full length is approximately 18-19 kb.

Response of plasma rotation to resonant magnetic perturbations in J-TEXT tokamak

Yan, W,Chen, Z Y,Huang, D W,Hu, Q M,Shi, Y J,Ding, Y H,Cheng, Z F,Yang, Z J,Pan, X M,Lee, S G,Tong, R H,Wei, Y N,Dong, Y B IOP 2018 Plasma physics and controlled fusion Vol.60 No.3

<P>The response of plasma toroidal rotation to the external resonant magnetic perturbations (RMP) has been investigated in Joint Texas Experimental Tokamak (J-TEXT) ohmic heating plasmas. For the J-TEXT’s plasmas without the application of RMP, the core toroidal rotation is in the counter-current direction while the edge rotation is near zero or slightly in the co-current direction. Both static RMP experiments and rotating RMP experiments have been applied to investigate the plasma toroidal rotation. The core toroidal rotation decreases to lower level with static RMP. At the same time, the edge rotation can spin to more than 20 km s<SUP>−1</SUP> in co-current direction. On the other hand, the core plasma rotation can be slowed down or be accelerated with the rotating RMP. When the rotating RMP frequency is higher than mode frequency, the plasma rotation can be accelerated to the rotating RMP frequency. The plasma confinement is improved with high frequency rotating RMP. The plasma rotation is decelerated to the rotating RMP frequency when the rotating RMP frequency is lower than the mode frequency. The plasma confinement also degrades with low frequency rotating RMP.</P>

Simulation of Axisymmetric Scramjet Combustion Flowfields Using Weno Navier-Stokes Solvers

Jaw-Yen Yang,J.C. Huang,Y S. Lai,C. S. Kuo 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

This study is based on the theory of gas dynamics and uses the Navier-Stokes equations as the governing equations to solve the fluid flow field problems of the scramjet. For the turbulent flow, we use the simple Spalart-Allmaras one equation turbulence model (S-A model) which produces better results for near wall and boundary layer flow field problems. The lower-upper symmetric Gauss-Seidel (LU-SGS) implicit scheme, whose results converge efficiently under steady state conditions, is combined with the Weighted Essentially Non-Oscillatory (WENO) scheme to construct a numerical model of the scramjet. Using the WENO scheme’s high-order accuracy and its non-oscillatory solution at discontinuous areas, we can solve supersonic flow field problems with multiple shock wave interactions. This simulation procedure is verified against two partial examples from literature to ensure its accuracy, and is then applied to a complete geometric model of a scramjet with different initial conditions for a full flow field analysis. The Mach number, density, static temperature and pressure are found and the results discussed. It is found that even when the shock waves are very close to each other, the WENO scheme produces better simulation results than other numerical approaches.

New self-activated eulytite-type compounds of M₇Zr(PO₄)₆ (M=Ca, Sr, Ba)

Qin, L.,Wei, D.,Huang, Y.,Kim, S.I.,Yu, Y.M.,Seo, H.J. Elsevier Sequoia 2013 Journal of alloys and compounds Vol.574 No.-

Eulytite-type orthophosphates M<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> (M=Ca, Sr, Ba) were prepared by conventional high temperature solid-state reaction. Sr<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> and Ba<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> crystallize in the pure eulytite-type phase with cubic space group (I4@?3d). The impurity phase β-Ca<SUB>3</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> was inevitably coexisted with the Ca<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> phase. The luminescence properties are investigated by UV-VUV excitation and emission spectroscopy and X-ray-excited luminescence (XEL) spectroscopy. The broad excitation and emission bands are observed due to the charge transfer transition from Zr<SUP>4+</SUP> to O<SUP>2-</SUP> in M<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> (M=Ca, Sr, Ba) eulytite. The characteristics of the phosphors including the luminescence mechanism are explained by Stokes shift, decay curves, and CIE color coordinates. The Sr<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>3</SUB> and Ba<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>3</SUB> phosphors exhibit unusual spectral features with the emission bands at 470 and 480nm, respectively. The weak luminescence centered at 495nm is observed in the Ca<SUB>7</SUB>Zr(PO<SUB>4</SUB>)<SUB>6</SUB> eulytite with lifetime of 4.67μs. The unusual self-activated luminescence is discussed on the base of the crystal structure of eulytite.

차세대 가속기용 공동형 빔위치 측정기 개발

Kim S.H.,Park Y.J.,Hwang W.H.,Huang J.Y.,Honda Y.,Inoue Y. 한국진공학회 2006 Applied Science and Convergence Technology Vol.15 No.4

국제 직선형 충돌 가속기 (ILC; International Linear Collider). 자유전자 레이저 (FEL: Free Electron Laser)와 같은 차세대 가속기에 사용 할 공동형 빔위치 측정기 ( 공동형 BPM: cavity-type beam position monitor)를 일본 고에너지 연구소 (KEK; High Energy Accelerator Research Organization)와 공동으로 개발하였다. ILC 및 FEL의 운전을 위해서는 빔 기반 정렬 (beam-based alignment)과 되먹임 장치 (feedback system)가 필수적으로 요구되는데, 이를 위해서는 적절한 위치에 서브마이크론의 분해능을 지닌 빔위치 측정기를 설치하여야 한다 [1]. 공동형 BPM은 기계적인 정밀도에 매우 민감하므로 정밀한 제작과 미세한 기계적 조정을 통하여 성능을 달성하게 된다. 우리는 제작 오차를 줄이기 위하여 공진 공동, 빔 튜브, 도파관, 전기도입기 등 모든 부품을 조립 후 한꺼번에 진공 브레이징 하였다. 공동의 외주면에는 네 개의 튜닝 핀을 두어 공진주파수 및 x-y 격리도 (x-y isolation between coupled waveguide)를 미세 조정할 수 있도록 하였다. 현재 개발된 공동형 BPM 은 공진주파수는 6.422 GHz 이며, 공동 내경은 53.822 mm, 빔의 위치 측정 범위는 ${\pm}250 {\mu}m$이다. network analyzer를 관측하면서 튜닝핀을 이용하여 x-y 격리도를 -40 dB 이하로 조정할 수 있었다. 실제 KEK ATF2에서의 전자빔을 이용한 시험에서 신호의 모양, x-y 격리도, 민감도 등에서 만족한 결과를 얻었다. Cavity-type beam position monitors were developed in collaboration with KEK to use for the future accelerators such as international linear collider (ILC) or x-ray free electron laser (XFEL) in PAL. BPM components such as BPM cavity, beam tubes, waveguides and feedthroughs were assembled by brazing at the same time to reduce mechanical errors during the fabrication. There are four screwed pins around outer rim of the cavity for the tuning of cavity frequency and x-y isolation. The resonance frequency of BPM is 6.422 GHz, the inner diameter of cavity is 53.822 mm, and the range of mechanical adjusting is $+ / - 250{\mu}m$. The x-y isolation was measured better than -40 dB after tuned. Test results of signal forms, x-y isolations, sensitivities are satisfied within requirements for the KEK ATF2 beam line.

Dietary Requirement of True Digestible Phosphorus and Total Calcium for Growing Pigs

Ruan, Z.,Zhang, Y.-G.,Yin, Y.-L.,Li, T.-J.,Huang, R.-L.,Kim, S.W.,Wu, G.Y.,Deng, Z.Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.8

Sixty healthy growing pigs ($Duroc{\times}Landrace{\times}Yorkshire$ with an average BW of 21.4 kg) were used to determine the true digestible phosphorus (TDP) requirement of growing pigs on the basis of growth performance and serum biochemical indices. Pigs were assigned randomly to one of five dietary treatments (12 pigs/diet), representing five levels of TDP (0.16%, 0.20%, 0.23%, 0.26% and 0.39%). There were three replications per treatment, with four pigs (2 barrows and 2 gilts) in each replication (2 pigs/pen) A randomized-block design was used, with pen as the experimental unit. Experimental diets were formulated to provide the 5 TDP levels with a total calcium (Ca) to TDP ratio of 2:1, and offered to pigs at 5% BW for 28 d. The total Ca contents of the five diets were 0.33, 0.38, 0.45, 0.51 and 0.79%, respectively. During the 28-d experimental period, the ADG of pigs was affected by dietary TDP levels as described by Equation 1: y = $-809,532x^4+788,079x^3-276,250x^2+42,114x-1$,759; ($R^2$ = 0.99; p<0.01; y = ADG, g/d; x = dietary TDP, %). The feed:gain ratio for pigs was affected by dietary TDP levels as described by Equation 2: y = $3,651.1x^4-3,480.4x^3+1,183.8x^2-172.5x+10.9$ ($R^2$ = 0.99; p<0.01; y = feed:gain ratio; x = dietary TDP, %). Total P concentrations in serum were affected by dietary TDP levels as described by Equation 3: y = $-3,311.7x^4+3,342.7x^3-1,224.6x^2+195.6x-8.7$ ($R^2$ = 0.99; p<0.01; y = total serum P concentration and x = dietary TDP, %). The highest ADG (782 g/d), the lowest feed:gain ratio (1.07), and the highest total serum P concentration (3.1 mmol/L) were obtained when dietary TDP level was 0.34%. Collectively, these results indicate that the optimal TDP requirement of growing pigs is 0.34% of the diet (e.g., 5.1 g/day for a 30-kg pig that consumed 1.5 kg feed daily) at a total Ca to TDP ratio of 2:1.

Understanding spin configuration in the geometrically frustrated magnet TbB₄: A resonant soft X-ray scattering study

Huang, H.,Jang, H.,Kang, B.Y.,Cho, B.K.,Kao, C.-C.,Liu, Y.-J.,Lee, J.-S. Elsevier 2018 Current Applied Physics Vol.18 No.11

<P>The frustrated magnet has been regarded as a system that could be a promising host material for the quantum spin liquid (QSL). However, it is difficult to determine the spin configuration and the corresponding mechanism in this system, because of its geometrical frustration (i.e., crystal structure and symmetry). Herein, we systematically investigate one of the geometrically frustrated magnets, the TbB4 compound. Using resonant soft x-ray scattering (RSXS), we explored its spin configuration, as well as Tb's quadrupole. Comprehensive evaluations of the temperature and photon energy/polarization dependences of the RSXS signals reveal the mechanism of spin reorientation upon cooling down, which is the sophisticated interplay between the Tb spin and the crystal symmetry rather than its orbit (quadrupole). Our results and their implications would further shed a light on the search for possible realization of QSL.</P>

Effects of Dietary Supplementation with Blended Essential Oils on Growth Performance, Nutrient Digestibility, Blood Profiles and Fecal Characteristics in Weanling Pigs

Huang, Y.,Yoo, J.S.,Kim, H.J.,Wang, Y.,Chen, Y.J.,Cho, J.H.,Kim, I.H. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.5

The influence of dietary supplementation with blended essential oil on growth performance, nutrient digestibility, blood profiles and fecal characteristics was evaluated in 125 crossed ((Duroc ${\times}$Yorkshire) ${\times}$Landrace) pigs (6.21${\pm}$0.20 kg initial body weight and 21 d average age). The pigs were allotted to the following treatments: i) NC (antibiotic free diet), ii) PC (NC diet+44 ppm tylosin), iii) T1 (NC diet+0.1% essential oil), iv) T2 (NC diet+0.1% essential oil (with 0.3% Benzoic acid)) and v) T3 (NC+22 ppm tylosin and 0.05% essential oil). Average daily gain (ADG) was improved in the T2 group on d 14 (p<0.05). In addition, nutrient digestibility was partially affected (both positively and negatively) by the treatments. Furthermore, the immune system was stimulated and the fecal pH and fecal noxious gases were improved in pigs that received the diets supplemented with essential oil (p<0.05). The appearance and score of diarrhea also tended to be lower in pigs that were subjected to the essential oil treatments. Collectively, the results of this study indicate that supplementation of the diet with blended essential oils could replace treatment with antibiotics to improve growth performance and fecal characteristics.

An improved particles model for stress sensitivity in low-permeability sandstones

S. H. Gai,H. Q. Liu,S. L. He,G. Lei,S. Y. Mo,X. Huang,Y. Yang,X. Chen 한국자원공학회 2016 Geosystem engineering Vol.19 No.2

Stress-dependent permeability and porosity of porous media is very important for the development of oil reservoirs, especially in low-permeability reservoirs. Porous structure can change in response to an increase in the effective stress to induce the decline of permeability and porosity, which ultimately affects the fluid flow property. In this study, a capillary module, considering the arrangement and the deformation of particles, has been established to express the stress sensitivity of porous media based on the particle packing model. The predictions of variation of permeability by the proposed model have been validated by comparing with the experimental data. The predictions by the current model show the same variation trend with the experimental data and are consistent with the compression experiments. The proposed variation of permeability with the increase in effective stress depends on the factors such as the arrangement of particles (contact angle), the deformation of particles (elastic module and Poisson’s ratio) and effective stress. The effects of these parameters on variation of permeability are discussed in detail.