Time Dependent Particle Emission From Fission Products

S. T. Holloway,Toshihiko Kawano,Peter Moller 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

Decay heating following nuclear fission is an important factor in the design of nuclear facilities; impacting a variety of aspects ranging from cooling requirements to shielding design. Calculations of decay heat, often assumed to be a simple product of activity and average decay product energy, are complicated by the so called ``pandemonium effect.'' Elucidated in the 1970?셲 this complication arises from beta-decays feeding high-energy nuclear levels; redistributing the available energy between betas and gammas. Increased interest in improving the theoretical predictions of decay probabilities has been, in part, motivated by the recent experimental effort utilizing the Total Absorption Gamma-ray Spectrometer (TAGS) to determine individual beta-decay transition probabilities to individual nuclear levels. Accurate predictions of decay heating require a detailed understanding of these transition probabilities, accurate representation of particle decays as well as reliable predictions of temporal inventories from fissioning systems. We will discuss a recent LANL effort to provide a time dependent study of particle emission from fission products through a combination of Quasiparticle Random Phase Approximation (QRPA) predictions of beta-decay probabilities, statistical Hauser-Feshbach techniques to obtain particle and gamma-ray emissions in statistical Hauser-Feshbach and the nuclear inventory code, CINDER.

Polymorphism of tandem repeat in promoter of 5-lipoxygenase in ASA-intolerant asthma: a positive association with airway hyperresponsiveness

Kim, S.-H.,Bae, J.-S.,Suh, C.-H.,Nahm, D.-H.,Holloway, J. W.,Park, H.-S. Wiley (Blackwell Publishing) 2005 Allergy Vol.60 No.6

<P>BACKGROUND: 5-Lipooxygenase (ALOX5) and 5-lipoxygenase-activating protein (ALOX5AP) are known as key enzymes in cysteinyl-leukotriene (cys-LT) production, critical mediators in aspirin acetylsalicyclic acid (ASA)-intolerant asthma (AIA). To date, studies of the promoter region of ALOX5 gene has revealed the potential influence of a variable number of tandem repeats of a Sp1- and Egr1-binding motif, on the transcription rate. METHODS: To understand the pathological process that arises from cys-LT overproduction in AIA, we genotyped ALOX5 Sp1 and ALOX5AP poly(A) repeat promoter polymorphism by fluorescent-based capillary electrophoresis in the Korean population. RESULTS: No significant differences in allele and genotype frequencies of the ALOX5 and ALOX5AP promoter polymorphisms were observed between the three groups. However, there was a strong association of the ALOX5 Sp1 repeat polymorphism with airway hyperresponsiveness (AHR; PC20 methacholine); AIA patients carrying a mutant allele (n > 5 or n < 5 repeats) showed increased AHR compared to AIA patients with wild-type genotype (P=0.003). CONCLUSION: Although the alleles of the ALOX5 and ALOX5AP promoter cannot be considered as a prominent risk factor in the development of AIA, the genetic variant of tandem repeat (GGGCGG; Sp1-binding motif) in ALOX5 promoter is associated with the severity of airway hyperresponsiveness in AIA patients.</P>

Association of thromboxane A2 receptor gene polymorphism with the phenotype of acetyl salicylic acid-intolerant asthma

Kim, S-H.,Choi, J-H.,Park, H-S.,Holloway, JW.,Lee, S-K.,Park, C-S.,Shin, H-D. Blackwell Scientific Publications 2005 Clinical and experimental allergy Vol.35 No.5

<P>Summary</P><P>Background and objective</P><P>The thromboxane A2 receptor (TBXA2R) is a receptor for a potent bronchoconstrictor, TBXA2 which is known to be related to bronchial asthma and myocardial infarction. TBXA2R antagonist and TBX synthase inhibitors have been found to be effective in the management of asthmatic patients. This study was aimed to evaluate whether genetic variants of TBXA2R may be related with development of acetyl salicylic acid (ASA)-intolerant asthma (AIA).</P><P>Methods</P><P>TBXA2R gene polymorphisms (TBXA2R+795T>C, TBXA2R+924T>C) were determined using a single-base extension method in 93 AIA patients compared with 172 patients with ASA-tolerant asthma (ATA) and 118 normal controls (NCs) recruited from the Korean population. HLA DPB1<SUP>*</SUP>0301 genotype was performed using a direct sequencing method.</P><P>Results</P><P>The rare C allele frequency of TBXA2R+795T>C was significantly higher in AIA than in ATA (<I>P</I>=0.03) and the TBXA2R+795T>C polymorphism was also associated with extent of percent fall in forced expiratory volume in 1 s (FEV<SUB>1</SUB>) after the inhalation of lysine–acetyl salicylic acid in AIA patients (<I>P</I>=0.009); AIA patients homozygous for the +795 C allele had a greater percent fall of FEV<SUB>1</SUB> compared with individuals with TBXA2R+795 CT or TT genotypes. The frequency of patients carrying both the TBXA2R+795T>C rare allele and HLA DPB1<SUP>*</SUP>0301 was significantly higher in AIA patients (29.4%) than in ATA patients (7.3%) (<I>P</I>=0.008, odds ratio=5.3).</P><P>Conclusion</P><P>These results suggest that the polymorphism of TBXA2R+795T>C may increase bronchoconstrictive response to ASA, which could contribute to the development of the AIA phenotype.</P>

Association of TNF-α genetic polymorphism with HLA DPB1^*0301

Kim, S. -H.,Ye, Y. -M.,Lee, S. -K.,Choi, J. -H.,Holloway, J. W.,Park, C. -S.,Park, H. -S. Blackwell Publishing Ltd 2006 Clinical and experimental allergy Vol.36 No.10

<P>Summary</P><P>Background</P><P>We speculated TNF-α can be one of candidate gene for aspirin-intolerant asthma (AIA) because TNF-α is pro-inflammatory cytokine and known to be increased level in asthmatic airways. In addition, genetic interaction between TNF-α and human antigen leucocyte (HLA) DPB1<SUP>*</SUP>0301, which is a strong genetic marker for AIA, was examined for its close location within chromosome 6.</P><P>Method</P><P>To investigate genetic association of TNF-α with an AIA phenotype, three study groups (163 patients with AIA, 197 patients with aspirin-tolerant asthma (ATA), 257 normal control subjects) were enrolled. Single nucleotide polymorphisms (SNPs) were genotyped using a single-base extension method and HLA DPB1 genotyping was determined by high-throughput sequencing method.</P><P>Results</P><P>All five SNPs of TNF-α were tested; there were no significant differences in allele and genotype frequencies among the three groups. However, significant association between TNF-α−308G>A polymorphism and atopy status was noted (<I>P</I><0.05). Gene to gene interaction between TNF-α−1031T>C (or −863C>A or −857C>A) and HLA DPB1<SUP>*</SUP>0301 could synergistically increase the susceptibility to AIA with odds ratio (OR) to 7.738 (or OR=8.184 for −863C>A, OR=7.500 for −857C>T, <I>P</I><0.001, respectively).</P><P>Conclusion</P><P>TNF-α promoter polymorphism may significantly increase susceptibility to AIA by gene-to-gene interaction with HLA DPB1<SUP>*</SUP>0301.</P>

Optimization of the Yellow Phosphor Concentration and Layer Thickness for Down-Conversion of Blue to White Light

Bera, D,Maslov, S,Lei Qian,Jae Soo Yoo,Holloway, P H IEEE 2010 Journal of display technology Vol.6 No.12

<P>A cerium-doped gadolinium-yttrium garnet yellow emitting phosphor was used to optimize the phosphor layer for down-conversion of blue light from InGaN inorganic light-emitting diode (iLED) to white. Optical, morphological and elemental characterizations of phosphor were carried out. Various amounts of the phosphor were dispersed in polymethyl methacrylate polymer (PMMA)-chlorobenzene solution. The phosphor layer thickness was optimized by varying the volume of the phosphor-PMMA mixture. Using a blue emitting (458 nm) iLED, a two times larger luminance efficacy (lm/W) was obtained from down-converted white light using a 37.5 μm thick 25 mm × 25 mm film prepared from 30 mg of phosphor in 500 μl of the PMMA-chlorobenzene solution.</P>

Applications of the Hauser-Feshbach Theory to Advanced Nuclear Sciences

T. Kawano,P. Talou,M. B. Chadwick,S. Holloway,P. Moller,T. Watanabe 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

Unique applications of the Hauser-Feshbach (HF) statistical theory in the nuclear science field, as well as the HF model code development at LANL are discussed. Our applied field in which HF is applicable is not necessarily limited to the particle-induced reactions. We combine the HF model with a theory of β-decay to calculate the β-delayed neutron and γ-ray emissions. These calculations can be performed for each β-decay precursor to estimate aggregate neutron and γ-ray energy release at fission. Another relatively new example at LANL is the ability to compute HF predictions with a Monte Carlo technique (MCHF), which gives all the correlated information.