First observation ofγγ→pp¯K+K−and search for exotic baryons inpKsystems

Shen, C. P.,Yuan, C. Z.,Adachi, I.,Aihara, H.,Asner, D. M.,Aulchenko, V.,Aushev, T.,Ayad, R.,Babu, V.,Badhrees, I.,Bakich, A. M.,Barberio, E.,Behera, P.,Bhardwaj, V.,Bhuyan, B.,Biswal, J.,Bobrov, A.,B American Physical Society 2016 Physical review. D Vol.93 No.11

<P>The process gamma gamma -> p (p) over barK(+)K(-) and its intermediate processes are measured for the first time using a 980 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The production of p (p) over barK(+)K(-) and a Lambda(1520)(0) ((Lambda) over bar (1520)(0)) signal in the pK(-) ((p) over barK(+)) invariant mass spectrum are clearly observed. However, no evidence for an exotic baryon near 1540 MeV/c(2), denoted as Theta(1540)(0) ((Theta) over bar (1540)(0)) or Theta(1540)(++) (Theta(1540)(--)), is seen in the pK(-) ((p) over barK(+)) or pK(+) ((p) over barK(-)) invariant mass spectra. Cross sections for gamma gamma -> p (p) over barK(+)K(-), Lambda(1520)(0)(p) over barK(+) + c.c. and the products sigma(gamma gamma -> Theta(1540)(0)(p) over barK(+) + c.c.)B(Theta(1540)(0) -> pK(-)) and sigma(gamma gamma -> Theta(1540)(++)(p) over barK(-) + c.c.)B(Theta(1540)(++) -> pK(+)) are measured. We also determine upper limits on the products of the chi(c0) and chi(c2) two-photon decay widths and their branching fractions to p (p) over barK(+)K(-) at the 90% credibility level.</P>

N₂/ CH₄가스비에 따른 Hydrogenated Amorphous Carbon Nitride 박막의 특성

장홍규(H. K. Jang),김근식(G. S. Kim),황보상우(S. W. Whangbo),이연승(Y. S. Lee),황정남(C. N. Whang),유영조(Y. Z. Yoo),김효근(H. G. Kim) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.3

DC saddle-field-plasma-enhanced chemical-vapor deposition(PECVD) 장치를 이용하여 상온에서 p-type Si (100) 기판위에 hydrogenated amorphous carbon nitride [a-C:H(N)]박막을 증착하였다. 원료가스인 CH₄과 N₂의 전체압력은 90 mTorr로 고정하고 N₂/CH₄비를 0에서 4까지 변화하면서 제작한 a-C:H(N) 박막의 미세 구조의 변화를 연구하였다. 진공조의 도달 진공도는 1×10^(-6) Torr이고, 본 실험시 CH₄+N₂가스의 유량은 5 sc㎝으로 고정하고 배기량을 조절하여 진공조의 가스 압력을 90 mTorr로 고정하였으며 기판에 200 V의 직류 bias 전압을 인가하였다. α-step과 X-ray photoelectron spectroscopy(XPS)를 이용한 분석결과 N₂/CH₄비가 0에서 0.5로 증가함에 따라 박막 두께는 4840 Å에서 2600 Å으로 급격히 감소하였으며, 박막내의 탄소에 대한 질소함유량(N/C비)는 N₂/CH₄비가 4일때 최대 0.25로 증가하는 것을 확인하였다. 또한 XPS 스펙트럼의 fitting 결과 N₂/CH₄비가 증가할수록 CN결합이 증가하였다. Fourier Transformation Infrared (FT-IR) 분석결과 N₂/CH₄비가 증가함에 따라 박막내의 C-H 결합은 감소하고, N-H, C≡N 결합은 증가하였다. Optical bandgap 측정 결 과 N₂/CH₄비가 0에서 4로 증가함에 따라 a-C:H(N)박막의 bandgap 에너지는 2.53 eV에서 2.3 eV로 감소하는 것을 확인하였다. Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with substrate bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of N₂to CH₄(N₂/CH₄), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at N₂/CH₄> 0.5, the thickness of the film gradually decreased with the increase of the N₂/CH₄. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of N₂/CH₄. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of N₂/CH₄. Optical band gap energy of the film decreased from 2.53 eV deposited with pure methane to 2.3 eV at the ratio of N₂/CH₄=4.

The Effect of Saturated Fatty Acids on Cellulose Digestion by the Rumen Anaerobic Fungus, Neocallimatix frontalis C5-1

Ha, J.K.,Lee, S.S.,Gao, Z.,Kim, C.-H.,Kim, S.W.,Ko, Jong Y.,Cheng, K.-J. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.7

The effects of various concentrations of saturated fatty acids (SFA; caprylic, capric and stearic acids) on the growth of the anaerobic fungus, Neocallimastix frontalis C5-1 isolated from the rumen of a Korean native goat were investigated. At higher concentrations of fatty acids (0.1%, w/v), the addition of SFA strongly decreased filter paper (FP) cellulose digestion and polysaccharide-degrading enzyme activity. The sensitivity of the rumen anaerobic fungus to the added fatty acids increased in the following order: caprylic ($C_{8:0}$)>capric($C_{10:0}$)>stearic($C_{18:0}$) acid, although stearic acid had no significant (p<0.05) inhibitory effects at any of the concentrations tested. However, the addition of SFA at lower concentrations (0.01 and 0.001% levels), did not inhibit FP cellulose degradation and enzyme activity. Furthermore, although these parameters were slightly stimulated by the addition of SFA, they were not statistically different from control values. This is the first report examining the effects of fatty acids on anaerobic gut fungi. We found that the lower levels of fatty acids used in this experiment were able to stimulate the growth and specific enzyme activities of rumen anaerobic fungi, whereas the higher levels of fatty acids were inhibitory with respect to fungal cellulolysis.

Asymmetric dibenzoylated monobenzotetraazacyclo[15]annulenenickel(II) complexes

Kim, E. H.,Kim, D. I.,Park, I. J.,Bae, Z. U.,Byun, J. C.,Na, H. G.,Park, Y. C. Gordon and Breach Science Pub 2007 Journal of coordination chemistry Vol.60 No.4

<P> The 15-membered asymmetric complexes, 3,11-di(p-Xbenzoyl)-2,4,10,12-tetramethyl-1,5,9,13-monobenzotetraazacyclo[15]annulenenickel(II), X = CH3, H, Cl, NO2 and OCH3, were synthesized and characterized. IR spectra of the benzoylated complexes showed an intense C=O stretching mode in the range 1630-1640 cm-1. Hammett plots of [image omitted]of π → π* and LMCT were linear with slopes of +0.379 and +0.339, respectively. 1H NMR signals of methyl groups showed shielding effects due to magnetic anisotropy of benzoyl groups, while other proton signals exhibited deshielding effects. 13C NMR spectra were consistent with 1H NMR. Voltammograms of complexes showed two irreversible oxidation peaks due to the ligands in the ranges +0.35 to +0.44 V and +0.74 to +0.86 V, respectively. A reduction wave involving nickel(II) was found in the range -2.50 to -2.70 V, depending on substituents on the benzoyl group. Hammett plots of the first and second oxidation potentials had linear slopes of +0.071 and +0.104, respectively. The structures of 2,4,10,12-tetramethyl-1,5,9, 13-monobenzotetraazacyclo[15]annulenenickel(II) (monoclinic, C2/c, a = 22.883(6), b = 10.358(3), c = 14.755(4) Å, &bgr; = 102.704(4)°, Z = 8, R1 [I > 2σ(I)] = 0.0295, wR2 [I > 2σ(I)] = 0.0744) and 3,11-di(p-methylbenzoyl)-2,4,10,12-tetramethyl-1,5,9,13-monobenzotetraazacyclo[15]annulenenickel(II) (orthorhombic, Pca21, a = 27.829(3), b = 10.3904(11), c = 10.4664(11) Å, Z = 4, R1 [I > 2σ(I)] = 0.0387, wR2 [I > 2σ(I)] = 0.0840) were determined using single-crystal X-ray methods.</P>

Radiation damage in helium ion – irradiated reduced activation ferritic/martensitic steel

L.D. Xia,W.B. Liu,H.P. Liu,J.H. Zhang,H. Chen,Z.G. Yang,C. Zhang 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.1

Nanocrystalline reduced activation ferritic/martensitic (RAFM) steel samples were prepared using surfacemechanical attrition treatment (SMAT). Un-SMATed and SMATed reduced activation ferritic/martensitic samples were irradiated by helium ions at 200 C and 350 C with 2 dpa and 8 dpa, respectively,to investigate the effects of grain boundaries (GBs) and temperature on the formation of Hebubbles during irradiation. Experimental results show that He bubbles are preferentially trapped at GBsin all the irradiated samples. Bubble denuded zones are clearly observed near the GBs at 350 C, whereasthe bubble denuded zones are not obvious in the samples irradiated at 200 C. The average bubble sizeincreases and the bubble density decreases with an increasing irradiation temperature from 200 C to350 C. Both the average size and density of the bubbles increase with an increasing irradiation dose from2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples butnot in the un-SMATed samples irradiated in the same conditions, which indicate t

Molecular Descriptor Subset Selection in Theoretical Peptide Quantitative Structure–Retention Relationship Model Development Using Nature-Inspired Optimization Algorithms

Z0c,uvela, Petar,Liu, J. Jay,Macur, Katarzyna,Bą,czek, Tomasz American Chemical Society 2015 ANALYTICAL CHEMISTRY - Vol.87 No.19

<P>In this work, performance of five nature-inspired optimization algorithms, genetic algorithm (GA), particle swarm optimization (PSO), artificial bee colony (ABC), firefly algorithm (FA), and flower pollination algorithm (EPA), was compared in molecular descriptor selection for development of quantitative structure retention relationship (QSRR) models for 83 peptides that originate from eight model proteins. The matrix with 423 descriptors was used as input, and QSRR models based on selected descriptors were built using partial least squares (PLS), whereas root mean square error of prediction (RMSEP) was used as a fitness function for their selection. Three performance criteria, prediction accuracy, computational cost, and the number of selected descriptors, were used to evaluate the developed QSRR models. The results show that all five variable selection methods outperform interval PLS (iPLS), sparse PLS (sPLS), and the full PLS model, whereas GA is superior because of its lowest computational cost and higher accuracy (RMSEP of 5.534%) with a smaller number of variables (nine descriptors). The GA-QSRR model was validated initially through Y-randomization. In addition, it was successfully validated with an external testing set out of 102 peptides originating from Bacillus subtilis proteomes (RMSEP of 22.030%). Its applicability domain was defined, from which it was evident that the developed GA-QSRR exhibited strong robustness. All the sources of the model's error were identified, thus allowing for further application of the developed methodology in proteomics.</P>

Differentiation of fasciolid (liver fluke) species by isoelectric focusing

C,G,Lee,G,L,Z immerman 대한수의학회 1991 대한수의학회 학술대회발표집 Vol.1991 No.-

Study of broad bandwidth vibrational energy harvesting system with optimum thickness of PET substrate

C.T. Pan,Z.H. Liu,Y.C. Chen 한국물리학회 2012 Current Applied Physics Vol.12 No.3

In this paper, we present the development of a flexible PET-based (polyethylene terephthalate; PET)vibrational energy harvesting system with broad bandwidth. This broad bandwidth harvesting system comprises of four units of individual ZnO (zinc oxide) piezoelectric harvester in the form of a cantilever structure connected in parallel, and rectifying circuit with storage module. This system has ability to convert mechanical energy into electrical energy from the varying ambient vibration. The design and simulation of a piezoelectric cantilever plate was described by using commercial software ANSYS FEA (Finite Element Analysis) to determine the optimum thickness of PET substrate, internal stress distribution,operation frequency and electric potential. With the optimum thickness predicted by developed accurate analytical formula analysis, the one-way mechanical strain that is efficient to enhance the induced electric potential can be controlled within the piezoelectric ZnO layer. In addition, the relationship among the model solution of piezoelectric cantilever plate equation, vibration-induced electric potential and electric power was realized. An individual piezoelectric harvester consists of flexible PET substrate, piezoelectric ZnO thin film with (002) c-axis preferred orientation, and selectively deposited UV-curable resin lump structure which is used to change the resonant frequency of the harvester. In combination with multi-harvesters and rectifying with storage module together, an energy harvesting system with broad bandwidth can be fabricated. One individual harvester achieves a maximum OCV (open-circuit voltage) up to 4 V with power density of 1.247 mW/cm3. So far, we succeeded in accomplishing a broad bandwidth system with operating frequency range within 100 Hze450 Hz to enhance powering efficiency. When the DC voltage (direct current voltage) across a storage module is charged up to 1.55 V after rectification, a flash LED (light emitting diode) is driven.

Zn-INDUCED DENSITY-CONTROLLED GROWTH OF β-SiC NANOTUBES WITH TUNABLE FIELD EMISSION AND HYDROPHOBIC PROPERTIES

G. Z. YANG,H. CUI,C. X. WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.5

Density-controlled single-crystalline β-SiC nanotubes were successfully synthesized on a large scale by adding Zn into the system via direct thermal evaporation of C60 onto silicon wafers at 1290°C. Interestingly, no Zn elements can be detected in the final products. However, the addition of Zn power is important because without Zn, density-controlled SiC nanotubes cannot be observed in our experiment. On the basis of the results, a possible growth mechanism was proposed to illustrate the role that Zn played in the growth process. The field emission and hydrophobic performances show strong dependence on the densities of as-synthesized β-SiC nanotubes. The density-controlled β-SiC nanotubes with tunable field emission and hydrophobic properties may have potential in the future of nanotechnology.

THE TAOS PROJECT: RESULTS FROM SEVEN YEARS OF SURVEY DATA

Zhang, Z.-W.,Lehner, M. J.,Wang, J.-H.,Wen, C.-Y.,Wang, S.-Y.,King, S.-K.,Granados, Á,. P.,Alcock, C.,Axelrod, T.,Bianco, F. B.,Byun, Y.-I.,Chen, W. P.,Coehlo, N. K.,Cook, K. H.,de Pater, I.,Kim American Institute of Physics 2013 The Astronomical journal Vol.146 No.1

<P>The Taiwanese-American Occultation Survey (TAOS) aims to detect serendipitous occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (<10<SUP>–3</SUP> events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS monitors typically ~500 stars simultaneously at a 5 Hz readout cadence with four telescopes located at Lulin Observatory in central Taiwan. In this paper, we report the results of the search for small Kuiper Belt objects (KBOs) in seven years of data. No occultation events were found, resulting in a 95% c.l. upper limit on the slope of the faint end of the KBO size distribution of q = 3.34-3.82, depending on the surface density at the break in the size distribution at a diameter of about 90 km.</P>