• Journal of the Korean Chemical Society
• /
• v.54 no.4
• /
• pp.387-394
• /
• 2010

The theoretical calculations for $B_nH_n$, $B_nH_{n+1}$, $B_nH_{n+2}$ (n = 3-6) have been considered at the B3LYP level of theory with the 6-311G$^*$ basis set. The optimized geometries, harmonic vibrational frequencies, and binding energies are evaluated to elucidate the thermodynamic stability and spectroscopic properties. The harmonic vibrational frequencies for the molecules considered in this study show all real numbers implying true minima and the binding energies are corrected using zero-point vibrational energies (ZPVE). The binding energies and average energies due to increasing of BH monomer are predicted.

• Kyungpook Mathematical Journal
• /
• v.56 no.4
• /
• pp.1125-1133
• /
• 2016

In this paper we introduce h(x)-B-Tribonacci and h(x)-B-Tri Lucas polynomials. We also obtain the identities for these polynomials.

• Journal of the Chungcheong Mathematical Society
• /
• v.23 no.2
• /
• pp.323-333
• /
• 2010

The biproduct bialgebra has been generalized to generalized biproduct bialgebra $B{\times}^L_H\;D$ in [5]. Let (D, B) be an admissible pair and let D be a bialgebra. We show that if generalized biproduct bialgebra $B{\times}^L_H\;D$ is a Hopf algebra with antipode s, then D is a Hopf algebra and the identity $id_B$ has an inverse in the convolution algebra $Hom_k$(B, B). We show that if D is a Hopf algebra with antipode $s_D$ and $s_B$ in $Hom_k$(B, B) is an inverse of $id_B$ then $B{\times}^L_H\;D$ is a Hopf algebra with antipode s described by $s(b{\times}^L_H\;d)={\Sigma}(1_B{\times}^L_H\;s_D(b_{-1}{\cdot}d))(s_B(b_0){\times}^L_H\;1_D)$. We show that the mapping system $B{\leftrightarrows}^{{\Pi}_B}_{j_B}\;B{\times}^L_H\;D{\rightleftarrows}^{{\pi}_D}_{i_D}\;D$ (where $j_B$ and $i_D$ are the canonical inclusions, ${\Pi}_B$ and ${\pi}_D$ are the canonical coalgebra projections) characterizes $B{\times}^L_H\;D$. These generalize the corresponding results in [6].

• Journal of the Korean Vacuum Society
• /
• v.10 no.1
• /
• pp.104-111
• /
• 2001

B-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films were prepared by plasma-enhanced chemical-vapor deposition in a gas mixture of $SiH_4, CH_4,\;and\; B_2H_6$. Physical and chemical properties of a-SiC:H films grown with varing the ratio of $B_2H_6/(SiH_4+CH_4)$ were characterized with various analysis methods including scanning electron microscopy (SEM), X-ray diffractometry (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, secondary ion mass spectroscopy (SIMS), UV absorption CH_4spectroscopy and electrical conductivity measurements. With the B-doping concentration, the doping efficiency and the micro-crystallinity were decreased and the film became amorphous when $B_2H_6/(SiH_4{plus}CH_4)$ was over $5{\times}10^{-3}$. The addition of $B_2H_6$ gas during deposition decreased the H content in the film by lowering the quantity of Si-C-H bonds. Consequently, the optical band gap and the activation energy of a-SiC:H films were decreased with increasing the B-doping level.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.28 no.1
• /
• pp.114-122
• /
• 1995

Defining the mechanisms of B cell diversification which establish the immune repertoire is fundamental to understand how the immune response is regulated. In this report, B cell differentiation and diversification focused on the regulation of immunoglobulin $V_H$ gene expression during ontogeny were analyzed by in situ hybridization technique. Fetal liver B cells in .different gestational days from 16d to 20d showed the predominant expression of $V_H7183$ and $V_HQ52$ without transition of repertoire during the observed gestation days. The two subsets of fetal liver B cells separated according to different differentiation stages based on the presence of tell surface immunoglobulin also did not indicate apparent difference in expressed $V_H$ gene family profiles. B cells in fetal spleen as an another hematopoietic lymphoid tissue in fetus also expressed similar $V_H$ gene repertoire to that in fetal liver B cells. This distinct pattern of $V_H$ gene expression in fetal B cells from that of adult B cells were not changed even after four weeks contact with adult bone marrow microenvironment supplied by the established adult bone marrow stromal cell layers. Thus, the restricted $V_H$ gene repertoire of B cells in fetus which is distinct from that in adult appears to be associated more with the genetic potential of fetal B cell progenitors and less with environmental influences or differentiation stages or compartmentalization.

• Journal of Welding and Joining
• /
• v.30 no.5
• /
• pp.70-75
• /
• 2012

This study is related to the laser weldability of AZ31B magnesium alloy, an all-purpose wrought alloy with good strength and ductility. In general, AZ31B is classified into AZ31B-H24 and AZ31B-O depending on temper designation. Thus, in this study, the laser weldability of AZ31B-H24 and AZ31B-O was investigated and compared. CW Nd:YAG laser was used to produce bead and butt joints. And the effects of welding conditions on the weldability of these joints were examined in detail. As a result of this study, AZ31B-H24 was found to have thinner oxide film and smaller grain size compared with AZ31B-O. Due to such difference, in bead welding, AZ31B-H24 had more wide welding range for full penetration compared with AZ31B-O. Furthermore, it was also confirmed that AZ31B-H24 and AZ31B-O have different welding conditions to obtain stable keyhole in butt welding.

• Korean Journal of Mathematics
• /
• v.32 no.1
• /
• pp.97-107
• /
• 2024

Let A ⊆ B be an extension of integral domains with characteristic zero. Let H(A, B) and h(A, B) be rings of composite Hurwitz series and composite Hurwitz polynomials, respectively. We simply call H(A, B) and h(A, B) composite Hurwitz rings of A and B. In this paper, we study when H(A, B) and h(A, B) are unique factorization domains (resp., GCD-domains, finite factorization domains, bounded factorization domains).

• Journal of Korean Neurosurgical Society
• /
• v.63 no.6
• /
• pp.707-716
• /
• 2020

Objective : The function of B7H3, a member of the B7 family of proteins, in neuroblastoma (NB) remains poorly characterized. Here we examine the expression pattern of B7H3 in clinical NB specimens and characterize the phenotype of B7H3 knock-down in NB cell line. Methods : Immunohistochemical (IHC) staining was carried out to assess the expression of B7H3 in clinical NB specimens. Survival association was analyzed using five Gene Expression Omnibus (GEO) datasets (GSE85047, GSE45480, GSE62564, GSE16476, GSE49710). Clonogenic survival and flow cytometry were performed after B7H3 knockdown to assess the cellular proliferation and cell survival in vitro. Impact of B7H3 silencing on NB growth was examined in vivo using the SH-SY5Y xenograft model. Results : On IHC staining, B7H3 was widely expressed in clinical NB specimens. Analysis of the transcriptional profiles of five GEO datasets clinically annotated NB specimens revealed that decreased B7H3 expression was associated with improved overall survival. B7H3 knockdown suppressed the proliferation of the SH-SY5Y NB model in vitro and in vivo. Cell cycle analysis revealed that B7H3 silencing induced G1/S arrest. This arrest was associated with the suppression of E2F1 expression and induction of Rb expression. Conclusion : Our results demonstrate that B7H3 expression correlate with clinical survival in NB patients. Preliminary studies suggest that B7H3 may mediate the G1/S transition.

• Microbiology and Biotechnology Letters
• /
• v.15 no.2
• /
• pp.112-115
• /
• 1987

Optimal pH temperature and sucrose content for the production of vitamin B$_{12}$ and riboflavin by Bacillus megaterium and Enterobacter aerogenes was studied by microbiological analysis. Optimal pH for the production of B$_{12}$ was 6.0 by B. megaterium while the pH for E. aerogenes was 5.0. However, upon the addition of sucrose the optimal pH for B. megaterium shifted to 7.5 but E. aerogenes remained at pH 5.0. In the absence of sucrose, pH did not influence the yields of riboflavin produced by either bacterium. Addition of sucrose stimulated synthesis of riboflavin by both bacteria. Temperature had little effect on the production of vitamins by either bacterium.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.6
• /
• pp.875-882
• /
• 2021

To minimize occupational noise induced hearing loss, it is recommended that workers should not be exposed to noise levels exceeding 85 dBA for over 8 h. In the present study, noise exposure levels were measured for seven workers based on their tasks on a training ship. The A-weighted noise exposure level (L_ex,24h) was measured by taking into account the A-weighted equivalent continuous sound level (L_Aeq,i), duration (h) and noise contribution (L_ex,24h,i) from the workers' locations. Results are thus obtained for different job categories as follows: officer group L_ex,24h=56.1 dB, navigation crew L_ex,24h=58.9 dB, navigation cadet L_ex,24h=62.0 dB, ship's cook L_ex,24h=64.3 dB, engine cadet L_ex,24h=91.1 dB, engineer L_ex,24h=91.1 dB, and engine crew L_ex,24h=95.1 dB. It was determined that the engineers, engine crews, and engine cadets in charge of machinery must wear hearing protection devices. By wearing hearing protection devices when working in highly noisy engine rooms, it is estimated that the noise expose levels could be reduced by the following amounts: engineer L_ex,24h=23.1 dB, engine Crew L_ex,24h=24.4 dB, and engine cadet L_ex,24h=21.5 dB. Moreover, if the no. 2 lecture room and mess room bottom plates in the cadets accommodations were improved to the 64 mm A-60-class floating plates, then further reductions are possible as follows: navigation cadet L_ex,24h=4.3 dB and engine cadet L_ex,24h=1.8 dB.