• Title/Summary/Keyword: Delta-Form

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Delta-form-based method of solving high order spatial discretization schemes for neutron transport

  • Zhou, Xiafeng;Zhong, Changming;Li, Fu
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2084-2094
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    • 2021
  • Delta-form-based methods for solving high order spatial discretization schemes are introduced into the reactor SN transport equation. Due to the nature of the delta-form, the final numerical accuracy only depends on the residuals on the right side of the discrete equations and have nothing to do with the parts on the left side. Therefore, various high order spatial discretization methods can be easily adopted for only the transport term on the right side of the discrete equations. Then the simplest step or other robust schemes can be adopted to discretize the increment on the left hand side to ensure the good iterative convergence. The delta-form framework makes the sweeping and iterative strategies of various high order spatial discretization methods be completely the same with those of the traditional SN codes, only by adding the residuals into the source terms. In this paper, the flux limiter method and weighted essentially non-oscillatory scheme are used for the verification purpose to only show the advantages of the introduction of delta-form-based solving methods and other high order spatial discretization methods can be also easily extended to solve the SN transport equations. Numerical solutions indicate the correctness and effectiveness of delta-form-based solving method.

Biological Functions of the COOH-Terminal Amino Acids of the $\alpha$-Subunit of Tethered Equine Chorionic Gonadotropin

  • Jeoung, Youn-Hee;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.34 no.1
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    • pp.47-53
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    • 2010
  • Glycoprotein hormones have a common $\alpha$-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the $\alpha$-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the $NH_2$-terminus of the $\alpha$-subunit to the COOH-terminus of the $\beta$-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form ${\Delta}96$, Lys was substituted at position 95 to form ${\Delta}95$, His was inserted at position 93 to form ${\Delta}93$ and Tyr was substituted at position 87 to form ${\Delta}87$. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and ${\Delta}96$, ${\Delta}95$, and ${\Delta}93$ mutants were efficiently secreted into the medium but the ${\Delta}87$ mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the ${\Delta}87$ mutant. However, the ${\Delta}87$ mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The ${\Delta}95$ and ${\Delta}93$ mutants were completely inactive in both the LH- and FSH-like activity assays. The ${\Delta}96$ mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the ${\Delta}96$ mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the a-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the $\alpha$-subunit is very important for the secretion and functioning of this hormone.

On $\delta$ -semiclassical orthogonal polynomials

  • K. H. Kwon;Lee, D. W.;Park, S. B.
    • Bulletin of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.63-79
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    • 1997
  • Consider an oparator equation of the form : $$ (1.1) H[y](x) = \alpha(x)\delta^2 y(x) + \beta(x)\delta y(x) = \lambda_n y(x), $$ where $\alphs(x)$ and $\beta(x)$ are polynomials of degree at most two and one respectively, $\lambda_n$ is the eigenvalue parameter, and $\delta$ is Hahn's operator $$ (1.2) \delta f(x) = \frac{(q - 1)x + \omega}{f(qx + \omega) - f(x)}, $$ for real constants $q(\neq \pm 1)$ and $\omega$.

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GENERAL TYPES OF(∈,∈∨qk)-FUZZY SUBSEMIGROUPS IN SEMIGROUPS

  • Kang, Jeong Gi
    • Honam Mathematical Journal
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    • v.38 no.4
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    • pp.795-807
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    • 2016
  • More general form of an (${\in},{\in}{\vee}q_k$)-fuzzy subsemigroup is considered. The notions of (${\in},q^{\delta}_k$)-fuzzy subsemigroup, ($q^{\delta}_0,{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup and (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup are introduced, and related properties are investigated. Characterizations of an (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup are considered. Conditions for an (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup to be a fuzzy subsemigroup are provided. Relations between ($q^{\delta}_0,{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup, (${\in},q^{\delta}_k$)-fuzzy subsemigroup and (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy subsemigroup are discussed.

Mg Delta-Doping Effect on a Deep Hole Center Related to Electrical Activation of a p-Type GaN Thin Film

  • Park, Hyo-Yeol;Jeon, Kyoung-Nam;Kim, Keun-Joo
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.1
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    • pp.37-41
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    • 2010
  • The authors investigated the photoluminescence (PL) and the electron paramagnetic resonance (EPR) from an magnesium (Mg)-doped GaN thin film with a delta-doped layer. The regularly doped sample shows a PL peak at 2.776 eV for the as-grown sample, and the peak shifts to 2.904 eV and increases in intensity for the annealed sample. The delta-doped sample also shows the same PL peak as does the regularly doped sample. However, only the annealed delta-doped layer shows a sharp EPR with a small isotropic Lande g-factor, $g_{II}$, of 2.029. This resonance is attributed to the delta-doped layer, which forms a hole-bound Mg-N atomic structure instead of the $Mg_{Ga}-V_N$ defect complex, indicating that the delta-doped sample was not optically activated to form PL centers but was instead electrically activated to form a hole-bound state.

AN EXTENSION ON GENERALIZED HYPERGEOMETRIC POLYNOMIALS

  • Shah, Manilal
    • Kyungpook Mathematical Journal
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    • v.11 no.1
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    • pp.93-99
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    • 1971
  • In this paper, the author has established the formulae for product of two generalized hypergeometric polynomials by defining the polynomial in the form $$F_n(x)=x^{({\delta}-1)n}{_{p+{\delta}}F_q}\[\array{{\Delta}({\delta},-n),&a_1,&{\cdots}{\cdots},&a_p\\&b_1,&{\cdots}{\cdots},&b_q};\;{\lambda}x^c\]$$, where the symbol ${\Delta}({\delta},-n)$ represents the set of ${\delta}$-parameters: $${\frac{-n}{\delta}},\;{\frac{-n+1}{\delta}},\;{\cdots}{\cdots},\;{\frac{-n+{\delta}-1}{\delta}}$$ and ${\delta}$, n are positive integers. A number of known as well as new results have been also obtained with proper choice of parameters.

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Fatigue crack growth and crack closure in 2017-T3 Aluminum alloy (2017 - T 3 알미늄 合金 의 勞龜裂進展 과 龜裂닫힘現象)

  • 송지호;김일현;신용승
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.4 no.2
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    • pp.47-53
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    • 1980
  • Kikukawa-Compliance method using a conventional clip-on gauge was employed to investigate fatigue crack growth and crack closure in 2017-T3 aluminum alloy. The crack growth rate plot against stress intensity range .DELTA.K on a log-log diagram exhibits a bilinear form with a transition at the growth rate of 10$\^$-4/ mm/cycle. The bilinear form appears still in the plot of growth rate versus effective stress intensity range .DELTA.K$\_$eff/. Fatigue crack growth rate could be well represented by .DELTA.K$\_$eff. The experimental results indicate that the effective stress intensity range ratio U depends on the maximum stress intensity factor K$\_$max/, but the stress ratio R does not affect U. The crack opening stress intensity factor K$\_$op/ tends to increase with increasing K$\_$max/ and decrease with increasing .DELTA.K.

Electrical Characteristics of Cathode Li($Mn_{1-\delta}$$M_{\delta}$)$_2$$O_4$ Substituted by Transition Metals in Li-Ion Secondary Batteries (전이금속 치환 리튬이온 이차전지 정극 Li($Mn_{1-\delta}$$M_{\delta}$)$_2$$O_4$의 전기적 특성)

  • 박재홍;김정식;유광수
    • Journal of the Korean Ceramic Society
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    • v.37 no.5
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    • pp.466-472
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    • 2000
  • As cathode materials of LiMn2O4-based lithium-ion secondary batteries, Li(Mn1-$\delta$M$\delta$)2O4 (M=Ni and Co, $\delta$=0, 0.05, 0.1 and 0.2) materials which Co and Ni are substituted for Mn, were syntehsized by the solid state reaction at 80$0^{\circ}C$ for 48 hours. No second phases were formed in Li(Mn1-$\delta$M$\delta$)2O4 system with substitution of Co. However, substitution of Ni caued to form a second phase of NiO when its composition exceeded over 0.2 of $\delta$ in Li(Mn1-$\delta$M$\delta$)2O4. As the results of charging-discharging test, the maximum capacity of Li(Mn1-$\delta$M$\delta$)2O4 appeared in $\delta$=0.1 for both Co and Ni. Also, Li(Mn1-$\delta$M$\delta$)2O4 electrode showed higher capacity and better cycle performance than LiMn2O4.

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Mind Bomb1 and DeltaD are Localized into Autophagosome after Endocytosis in Zebrafish during Neurogenesis

  • Kim, Min-Jung
    • Development and Reproduction
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    • v.15 no.3
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    • pp.215-221
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    • 2011
  • Endocytosis of the Notch ligand, DeltaD, by mind bomb1 is indispensable for activation of Notch in cell fate determination, proliferation, and differentiation during zebrafish neurogenesis. Loss of mind bomb1 activity as an E3 Ubiquitin ligase causes the accumulation of deltaD at the plasma membrane and results in the ectopic neurogenic phenotype by activation of Notch in early zebrafish embryogenesis. However, the regulatory mechanism of deltaD during neurogenesis is not identified yet. This study aims to analyze the pathway of mib1 and deltaD after endocytosis in vivo during zebrafish embryogenesis. Mind bomb1 and deltaD are co-localized into autophagosome and mutant form of mind bomb1 fails to cargo deltaD into autophagosomes. These findings suggest that mind bomb I mediates deltaD regulation by autophagy in an ubiquitin-dependent manner during zebrafish embryogenesis.

Delta-Sigma Modulator Structure and limit Cycle Generation (델타시그마 변환기 구조와 Limit Cycle 발생)

  • Hyun, Deok-Hwan
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.1 s.307
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    • pp.39-44
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    • 2006
  • Pattern noise in the Delta-Sigma modulator is a well Known phenomenon that intrigued many circuit designers. These noise appear as the modulator output falls into a cyclic mode of operation. This paper addresses the dependence of these tone signal upon the system topologies. Among the four well known single-stage DSM topologies, namely Cascade of Integrators with Feedback Form(CIFB), Cascade of Integrators with Feedforward Form(CIFF), Cascade of Resonators with Feedback Form(CRFB), and Cascade of Resonators with Feedforward Form(CRFF), resonator type DSMs turn out to be more susceptible to the pattern noise than the integrator type. Noise transfer functions of the investigated topologies are also presented.