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Sample records for cross sectional epidemiological

  1. Psychiatric problems in children with hemiplegia: cross sectional epidemiological survey.

    PubMed

    Goodman, R; Graham, P

    1996-04-27

    To examine the prevalence and predictors of psychiatric problems in children with hemiplegia. Cross sectional questionnaire survey of an epidemiological sample with individual assessments of a representative subgroup. The questionnaire survey was repeated on school age subjects four years later. 428 hemiplegic children age 2 1/2-16 years, of whom 149 (aged 6-10 years) were individually assessed. Psychiatric symptom scores and the occurrence of psychiatric disorder. Psychiatric disorders affected 61% (95% confidence interval 53% to 69%) of subjects as judged by individual assessments and 54% (49% to 59%) and 42% (37% to 47%) as judged from parent and teacher questionnaires, respectively. Few affected children had been in contact with child mental health services. The strongest consistent predictor of psychiatric problems was intelligence quotient (IQ), which was highly correlated with an index of neurological severity; age, sex, and laterality of lesion had little or no predictive power. Though most hemiplegic children have considerable emotional or behavioural difficulties, these psychological complications commonly go unrecognised or untreated. Comprehensive health provision for children with chronic neurodevelopmental disorders such as hemiplegia should be psychologically as well as physically oriented.

  2. Psychiatric problems in children with hemiplegia: cross sectional epidemiological survey.

    PubMed Central

    Goodman, R.; Graham, P.

    1996-01-01

    OBJECTIVE--To examine the prevalence and predictors of psychiatric problems in children with hemiplegia. DESIGN--Cross sectional questionnaire survey of an epidemiological sample with individual assessments of a representative subgroup. The questionnaire survey was repeated on school age subjects four years later. SUBJECTS--428 hemiplegic children age 2 1/2-16 years, of whom 149 (aged 6-10 years) were individually assessed. MAIN OUTCOME MEASURES--Psychiatric symptom scores and the occurrence of psychiatric disorder. RESULTS--Psychiatric disorders affected 61% (95% confidence interval 53% to 69%) of subjects as judged by individual assessments and 54% (49% to 59%) and 42% (37% to 47%) as judged from parent and teacher questionnaires, respectively. Few affected children had been in contact with child mental health services. The strongest consistent predictor of psychiatric problems was intelligence quotient (IQ), which was highly correlated with an index of neurological severity; age, sex, and laterality of lesion had little or no predictive power. CONCLUSION--Though most hemiplegic children have considerable emotional or behavioural difficulties, these psychological complications commonly go unrecognised or untreated. Comprehensive health provision for children with chronic neurodevelopmental disorders such as hemiplegia should be psychologically as well as physically oriented. PMID:8616413

  3. Epidemiological Study of Sepsis in China: Protocol of a Cross-sectional Survey

    PubMed Central

    Yang, Yi; Xie, Jian-Feng; Yu, Kai-Jiang; Yao, Chen; Li, Jian-Guo; Guan, Xiang-Dong; Yan, Jing; Ma, Xiao-Chun; Kang, Yan; Yang, Cong-Shan; Yao, Xiao-Qing; Shang, Hong-Cai; Qiu, Hai-Bo

    2016-01-01

    Background: Sepsis is the leading cause of death among critically ill patients. Herein, we conducted a national survey to provide data on epidemiology and treatment of sepsis in the clinical practice in China, which has no detailed epidemiological data available on sepsis. Methods: This was a prospective cross-sectional survey from December 1, 2015 to January 31, 2016 in all provinces/municipalities of the mainland of China. The primary outcome of this study was the incidence of sepsis, and the secondary outcome was its etiology in China. Patients with sepsis admitted to the Intensive Care Units were included in this study. The demographic, physiological, bacteriological, and therapeutic data of these patients were recorded. The incidence of sepsis was estimated using the data from the sixth census in China, reported by the Chinese National Health and Family Planning Commission and the National Bureau of Statistics as the standard population. The independent risk factors for increased mortality from sepsis were calculated. Conclusions: This study indicated the incidence and outcome of sepsis in China. It also showed the most common etiology of different sites and types of infection, which could guide empiric antibiotic therapy. Moreover, it provided information on the independent risk factors for increased mortality due to sepsis. The findings provide evidence to guide clinical management and may help improve the outcome in septic patients. Trial Registration: ClinicalTrials.gov, NCT02448472; https://clinicaltrials.gov/show/NCT02448472. PMID:27958229

  4. Clergy-laity support and patients’ mood during serious illness: A cross-sectional epidemiologic study

    PubMed Central

    Hays, Judith C.; Wood, Laura; Steinhauser, Karen; Olson, Maren K.; Lindquist, Jennifer H.; Tulsky, James

    2013-01-01

    Objectives Religious participation is positively associated with mental health, but attendance at worship services declines during serious illness. This study assessed whether home visits by clergy or laity provide benefits to seriously ill patients who may have difficulty attending religious services. Design and sample A cross-sectional study design nested in an observational epidemiologic cohort study. The regionally-representative sample of patients had metastatic lung, colorectal, breast, and prostate cancer (n=70), Class III and IV congestive heart failure (n=70), or chronic obstructive pulmonary disease with hypercapnea (n=70) and observed regarding clergy-laity support in their naturalistic environments. Measures Dependent variable: 10-item Center for Epidemiologic Studies – Depression scale. Independent variable: A one-item question measuring how much helpful support patients received from clergy or other persons from church, temple, synagogue, or mosque Covariates: demographic, health, social support, religiousness. Analysis Descriptive, bivariate, and general linear models Results Depressed mood was negatively associated with clergy-laity support in a non-linear pattern. Depressed mood was also positively associated with functional deficits and a lifetime history of difficulties related to religious involvement. Conclusions In lieu of worship attendance when people are sick, home visits by members of a patient’s religious community may bolster mood by providing continuity of instrumental, emotional, and spiritual support. PMID:21838948

  5. A cross-sectional epidemiological study of domestic animals related to human leptospirosis cases in Nicaragua.

    PubMed

    Flores, Byron J; Pérez-Sánchez, Tania; Fuertes, Héctor; Sheleby-Elías, Jessica; Múzquiz, José Luis; Jirón, William; Duttmann, Christianne; Halaihel, Nabil

    2017-02-28

    Leptospirosis is one of the most extended zoonosis worldwide and humans become infected most commonly through contact with the urine of carrier animals, either directly or via contaminated water or soil. The aim in this study was to analyse the epidemiological behaviour of Leptospira spp., from domestic animals around the sites of human leptospirosis cases in Nicaragua, from 2007 through 2013. We report the results of a cross-sectional epidemiological study with a non-probability sampling of blood (n=3050) and urine (n=299) from Domestic Animals (DA) around the sites of human leptospirosis cases in Nicaragua. We analysed data obtained through Microscopic Agglutination Test (MAT), in-vitro culture, real time PCR and sequencing of lfb1 locus. Frequencies of 30.31% (95% CI: 28.66-31.95) and 15.38% (95% CI: 11.12-19.64) were obtained from serological test and from in-vitro culture, respectively. Although similar frequencies from serology test (P≥0.05) were found in DA species, in-vitro culture frequencies were significantly higher from bovine, equine and sheep (P<0.05) in comparison with swine and canine species. Ten serogroups of pathogenic Leptospira spp. were encountered, with the highest presence of Icterohaemorrhagiae serogroup 34.65% (95% CI: 29.35-39.94). We identified 7 samples homologous to L. interrogans species Pyrogenes serovar and 3 samples as L. noguchii Louisiana or Panama serovars by analysis of lfb1 sequences. We were able to establish a temporal and spatial correlation from DA and cumulative incidence of human cases. Therefore an effective epidemiological surveillance should be implemented with a specific control program toward DA in order to reduce human leptospirosis incidence.

  6. Epidemiology and Reporting Characteristics of Systematic Reviews of Biomedical Research: A Cross-Sectional Study

    PubMed Central

    Page, Matthew J.; Shamseer, Larissa; Altman, Douglas G.; Tetzlaff, Jennifer; Tricco, Andrea C.; Catalá-López, Ferrán; Li, Lun; Reid, Emma K.; Sarkis-Onofre, Rafael; Moher, David

    2016-01-01

    Background Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. Methods and Findings We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using prespecified eligibility criteria. Epidemiological and reporting characteristics of a random sample of 300 SRs were extracted by one reviewer, with a 10% sample extracted in duplicate. We compared characteristics of Cochrane versus non-Cochrane reviews, and the 2014 sample of SRs versus a 2004 sample of SRs. We identified 682 SRs, suggesting that more than 8,000 SRs are being indexed in MEDLINE annually, corresponding to a 3-fold increase over the last decade. The majority of SRs addressed a therapeutic question and were conducted by authors based in China, the UK, or the US; they included a median of 15 studies involving 2,072 participants. Meta-analysis was performed in 63% of SRs, mostly using standard pairwise methods. Study risk of bias/quality assessment was performed in 70% of SRs but was rarely incorporated into the analysis (16%). Few SRs (7%) searched sources of unpublished data, and the risk of publication bias was considered in less than half of SRs. Reporting quality was highly variable; at least a third of SRs did not report use of a SR protocol, eligibility criteria relating to publication status, years of coverage of the search, a full Boolean search logic for at least one database, methods for data extraction, methods for study risk of bias assessment, a primary

  7. Epidemiological and Clinical Characteristics of Fall Injuries in East Azerbaijan, Iran; A Cross-Sectional Study

    PubMed Central

    Ghaffari-Fam, Saber; Sarbazi, Ehsan; Daemi, Amin; Sarbazi, Mohamadreza; Riyazi, Lachin; Sadeghi-Bazargani, Homayoun; Allahyari, Ali

    2015-01-01

    Objective: To describe the epidemiological and clinical characteristics of fall injuries in East Azerbaijan, Iran. Methods: This cross-sectional study was based on Hospital Information System (HIS) data for patients referred to the Imam Reza Hospital between 2008 and 2013. We recorded the demographic characteristics and epidemiological patterns of patients who were admitted to our center due to fall injuries. To standardize the reports the International Classification of Diseases (ICD), the International Classification of Diseases 9 Clinical Modification (ICD-9-CM) was used. Equally, the hospitalization period and number, admission ward, and the final status of victims after discharge from the hospital were extracted from the HIS. Results: Overall we included a total number of 3397 patients with mean age of 39.2±22.7 years. There were 2501 (73.6%) men among the patients. Long bone fracture (48.1%) and intracranial injury (24.2%) were the most frequent injuries among fall injury victims. Operations on spinal cord and spinal canal structures (12.0%), Operations on nose (11.6%) were the most common operations being performed in these patients. The survival was significantly lower in patients with age more than 60 years when compared to other age groups (p=0.001). The survival rate was significantly lower in age group of >60 years, compared to other age groups (p=0.001). Conclusion: Given the high rate of fall injuries and death among the elderly that increases with age, appropriate measures must be taken to control and prevent injuries while prioritizing the elderly. PMID:27162912

  8. Smoking and nicotine dependence in Singapore: findings from a cross-sectional epidemiological study.

    PubMed

    Picco, Louisa; Subramaniam, Mythily; Abdin, Edimansyah; Vaingankar, Janhavi A; Chong, Siow Ann

    2012-08-01

    Smoking is one of the leading preventable causes of death throughout the world and can lead to nicotine dependence, particularly when initiated at a young age. This paper describes the prevalence of smoking and nicotine dependence in the adult Singapore resident population, whilst also exploring rates among the major ethnic groups (Chinese, Malay and Indian), different education levels and those with chronic psychiatric and physical comorbidities. The Singapore Mental Health Study (SMHS) is a cross-sectional epidemiological study that was conducted between December 2009 and December 2010. Information on smoking status was assessed using the Composite International Diagnostic Interview version 3.0 (CIDI 3.0) and the Fagerstrom Test for Nicotine Dependence measured nicotine dependence. Socio-demographic information was also collected. In total, 6616 respondents participated in the SMHS giving a response rate of 75.9%. We found that 16% of the population were current smokers and 4.5% had nicotine dependence. Current smokers were more likely to be younger (18 to 34 years old), males, Malay and have lower education, whilst males had a 4.6 times higher risk of nicotine dependence to that of females. The prevalence of nicotine dependence was also higher in those with alcohol abuse and those experiencing chronic pain. The results from this study highlight the important differences in the prevalence of smoking and nicotine dependence among different age groups, gender and ethnicity in Singapore and are important for developing future health policies and targeted preventive strategies.

  9. Ice cream headache in students and family history of headache: a cross-sectional epidemiological study.

    PubMed

    Zierz, Antonia Maria; Mehl, Theresa; Kraya, Torsten; Wienke, Andreas; Zierz, Stephan

    2016-06-01

    Headache attributed to ingestion of a cold stimulus (ICHD-3 beta 4.5.1) is also known as ice cream headache (ICH). This cross-sectional epidemiological study included 283 students (10-14-year-olds) attending a grammar school in Germany, their parents (n = 401), and 41 teachers. A self-administered questionnaire was used to analyze the prevalence and characteristics of ICH based on the ICHD classification. Additionally, the association between ICH and other headaches was investigated in students and parents. Prevalence of ICH in students was 62 % without gender difference. In adults, only 36 % of females and 22 % of males reported ICH. There was an increased risk for ICH in students when mother (OR 10.7) or father (OR 8.4) had ICH. Other headaches in parents had no influence on the prevalence of ICH in students. However, in the groups of students and parents itself there was a highly significant association between ICH and other headaches (students: OR 2.4, mothers: OR 2.9, fathers: OR 6.8). There was a decreased risk for ICH when parents and students had no headache at all (OR < 0.4). ICH in students clearly shows a familial disposition by both father and mother. There was also an association between ICH and other headaches within the student and adult groups. The absence of headache history seems to be a protective factor for ICH.

  10. Molecular Epidemiology of Amoebiasis: A Cross-Sectional Study among North East Indian Population

    PubMed Central

    Nath, Joyobrato; Ghosh, Sankar Kumar; Singha, Baby; Paul, Jaishree

    2015-01-01

    Background Epidemiological studies carried out using culture or microscopy in most of the amoebiasis endemic developing countries, yielded confusing results since none of these could differentiate the pathogenic Entamoeba histolytica from the non-pathogenic Entamoeba dispar and Entamoeba moshkovskii. The Northeastern part of India is a hot spot of infection since the climatic conditions are most conducive for the infection and so far no systemic study has been carried out in this region. Methodology/Principal Findings Following a cross-sectional study designed during the period 2011–2014, a total of 1260 fecal samples collected from the Northeast Indian population were subjected to microscopy, fecal culture and a sensitive and specific DNA dot blot screening assay developed in our laboratory targeting the Entamoeba spp. Further species discrimination using PCR assay performed in microscopy, culture and DNA dot blot screening positive samples showed E. histolytica an overall prevalence rate of 11.1%, 8.0% and 13.7% respectively. In addition, infection rates of nonpathogenic E. dispar and E. moshkovskii were 11.8% (95% CI = 10.2, 13.8) and 7.8% (95% CI = 6.4, 9.4) respectively. The spatial distributions of infection were 18.2% (107/588) of Assam, 11.7% (23/197) of Manipur, 10.2% (21/207) of Meghalaya, and 8.2% (22/268) of Tripura states. Association study of the disease with demographic features suggested poor living condition (OR = 3.21; 95% CI = 1.83, 5.63), previous history of infection in family member (OR = 3.18; 95% CI = 2.09, 4.82) and unhygienic toilet facility (OR = 1.79; 95% CI = 1.28, 2.49) as significant risk factors for amoebiasis. Children in age group <15 yr, participants having lower levels of education, and daily laborers exhibited a higher infection rate. Conclusions/Significance Despite the importance of molecular diagnosis of amoebiasis, molecular epidemiological data based on a large sample size from endemic countries are rarely reported in the

  11. Molecular Epidemiology of Amoebiasis: A Cross-Sectional Study among North East Indian Population.

    PubMed

    Nath, Joyobrato; Ghosh, Sankar Kumar; Singha, Baby; Paul, Jaishree

    2015-12-01

    Epidemiological studies carried out using culture or microscopy in most of the amoebiasis endemic developing countries, yielded confusing results since none of these could differentiate the pathogenic Entamoeba histolytica from the non-pathogenic Entamoeba dispar and Entamoeba moshkovskii. The Northeastern part of India is a hot spot of infection since the climatic conditions are most conducive for the infection and so far no systemic study has been carried out in this region. Following a cross-sectional study designed during the period 2011-2014, a total of 1260 fecal samples collected from the Northeast Indian population were subjected to microscopy, fecal culture and a sensitive and specific DNA dot blot screening assay developed in our laboratory targeting the Entamoeba spp. Further species discrimination using PCR assay performed in microscopy, culture and DNA dot blot screening positive samples showed E. histolytica an overall prevalence rate of 11.1%, 8.0% and 13.7% respectively. In addition, infection rates of nonpathogenic E. dispar and E. moshkovskii were 11.8% (95% CI = 10.2, 13.8) and 7.8% (95% CI = 6.4, 9.4) respectively. The spatial distributions of infection were 18.2% (107/588) of Assam, 11.7% (23/197) of Manipur, 10.2% (21/207) of Meghalaya, and 8.2% (22/268) of Tripura states. Association study of the disease with demographic features suggested poor living condition (OR = 3.21; 95% CI = 1.83, 5.63), previous history of infection in family member (OR = 3.18; 95% CI = 2.09, 4.82) and unhygienic toilet facility (OR = 1.79; 95% CI = 1.28, 2.49) as significant risk factors for amoebiasis. Children in age group <15 yr, participants having lower levels of education, and daily laborers exhibited a higher infection rate. Despite the importance of molecular diagnosis of amoebiasis, molecular epidemiological data based on a large sample size from endemic countries are rarely reported in the literature. Improved and faster method of diagnosis employed here to

  12. An epidemiological survey in hospital setup in Lucknow district: A cross-sectional study

    PubMed Central

    Pal, Uma Shanker; Singh, Mayank; Kumar, Lakshya; Verma, Pankaj; Singh, R. K.; Kumar, Shailendra; Agarwal, G. G.; Asthana, Akash

    2016-01-01

    Introduction: Oral cancer is the sixth most common form of cancer reported globally which includes lip, tongue, mouth, and throat. Developing countries face several challenges to identify and remove potential risk factors. Chewing tobacco/pan masala is considered to be the most potential risk factor for oral precancerous lesions and oral cancer. Objective: To study the clinical-epidemiological profile of oral cancer cases and potential risk factor associated with it. Materials and Methods: This is cross-sectional study which includes all major tertiary hospital in Lucknow district. Five hundred and eight cases of oral cancer reported in all major tertiary hospitals in Lucknow district during 2013–2016. Study Variable: Clinicoepidemiological characteristics of oral cancer cases. Statistical Analysis: percentages, proportions. Results: Out of 508 cases, majority of the subjects included in the study belonged to 18–75 years age group. Reported cases of oral cancer in males were higher as compared to females. Most of the subjects belonged to lower middle and upper lower socioeconomic group. It was found that 199 (39.2%) subjects consumed smokeless tobacco. Buccal mucosa was the common site of oral cancer being present in 50.4% of the subjects. Histopathologically, 256 cases of buccal mucosa, 17 cases of lip, 33 cases of alveolar region, 16 cases of mandible region, 156 cases of tongue region, 7 cases of gingival buccal sulcus region, and 23 cases of palate were diagnosed as oral squamous cell carcinoma. Conclusion: In the present study, the most affected site was buccal mucosa (50.4%), tongue (30.7%), and other diagnosis was <10%. PMID:28356689

  13. Epidemiology of injuries in elite taekwondo athletes: two Olympic periods cross-sectional retrospective study.

    PubMed

    Altarriba-Bartes, Albert; Drobnic, Franchek; Til, Lluís; Malliaropoulos, Nikolaos; Montoro, José Bruno; Irurtia, Alfredo

    2014-02-14

    Taekwondo injuries differ according to the characteristics of the athletes and the competition. This analytical cross-sectional retrospective cohort study aimed to describe reported taekwondo injuries and to determine the prevalence, characteristics and possible risk factors for injuries sustained by athletes of the Spanish national team. In addition, we compared each identified risk factor-age, weight category, annual quarter, injury timing and competition difficulty level-with its relation to injury location and type. Injury occurrences in taekwondo athletes of the Spanish national team during two Olympic periods at the High Performance Centre in Barcelona were analysed. 48 taekwondo athletes (22 male, 26 female; age range 15-31 years) were studied; 1678 injury episodes occurred. Inclusion criteria were: (1) having trained with the national taekwondo group for a minimum of one sports season; (2) being a member of the Spanish national team. Independently of sex or Olympic period, the anatomical sites with most injury episodes were knee (21.3%), foot (17.0%), ankle (12.2%), thigh (11.4%) and lower leg (8.8%). Contusions (29.3%) and cartilage (17.6%) and joint (15.7%) injuries were the prevalent types of injury. Chronological age, weight category and annual quarter can be considered risk factors for sustaining injuries in male and female elite taekwondists according to their location and type (p≤0.001). This study provides epidemiological information that will help to inform future injury surveillance studies and the development of prevention strategies and recommendations to reduce the number of injuries in taekwondo competition.

  14. Epidemiology of injuries in elite taekwondo athletes: two Olympic periods cross-sectional retrospective study

    PubMed Central

    Altarriba-Bartes, Albert; Drobnic, Franchek; Til, Lluís; Malliaropoulos, Nikolaos; Montoro, José Bruno; Irurtia, Alfredo

    2014-01-01

    Objective Taekwondo injuries differ according to the characteristics of the athletes and the competition. This analytical cross-sectional retrospective cohort study aimed to describe reported taekwondo injuries and to determine the prevalence, characteristics and possible risk factors for injuries sustained by athletes of the Spanish national team. In addition, we compared each identified risk factor—age, weight category, annual quarter, injury timing and competition difficulty level—with its relation to injury location and type. Settings Injury occurrences in taekwondo athletes of the Spanish national team during two Olympic periods at the High Performance Centre in Barcelona were analysed. Participants 48 taekwondo athletes (22 male, 26 female; age range 15–31 years) were studied; 1678 injury episodes occurred. Inclusion criteria were: (1) having trained with the national taekwondo group for a minimum of one sports season; (2) being a member of the Spanish national team. Results Independently of sex or Olympic period, the anatomical sites with most injury episodes were knee (21.3%), foot (17.0%), ankle (12.2%), thigh (11.4%) and lower leg (8.8%). Contusions (29.3%) and cartilage (17.6%) and joint (15.7%) injuries were the prevalent types of injury. Chronological age, weight category and annual quarter can be considered risk factors for sustaining injuries in male and female elite taekwondists according to their location and type (p≤0.001). Conclusions This study provides epidemiological information that will help to inform future injury surveillance studies and the development of prevention strategies and recommendations to reduce the number of injuries in taekwondo competition. PMID:24531455

  15. Cross-sectional Comparison of the Epidemiology of DSM-5 Generalized Anxiety Disorder Across the Globe.

    PubMed

    Ruscio, Ayelet Meron; Hallion, Lauren S; Lim, Carmen C W; Aguilar-Gaxiola, Sergio; Al-Hamzawi, Ali; Alonso, Jordi; Andrade, Laura Helena; Borges, Guilherme; Bromet, Evelyn J; Bunting, Brendan; Caldas de Almeida, José Miguel; Demyttenaere, Koen; Florescu, Silvia; de Girolamo, Giovanni; Gureje, Oye; Haro, Josep Maria; He, Yanling; Hinkov, Hristo; Hu, Chiyi; de Jonge, Peter; Karam, Elie G; Lee, Sing; Lepine, Jean-Pierre; Levinson, Daphna; Mneimneh, Zeina; Navarro-Mateu, Fernando; Posada-Villa, José; Slade, Tim; Stein, Dan J; Torres, Yolanda; Uda, Hidenori; Wojtyniak, Bogdan; Kessler, Ronald C; Chatterji, Somnath; Scott, Kate M

    2017-05-01

    Generalized anxiety disorder (GAD) is poorly understood compared with other anxiety disorders, and debates persist about the seriousness of this disorder. Few data exist on GAD outside a small number of affluent, industrialized nations. No population-based data exist on GAD as it is currently defined in DSM-5. To provide the first epidemiologic data on DSM-5 GAD and explore cross-national differences in its prevalence, course, correlates, and impact. Data come from the World Health Organization World Mental Health Survey Initiative. Cross-sectional general population surveys were carried out in 26 countries using a consistent research protocol and assessment instrument. A total of 147 261 adults from representative household samples were interviewed face-to-face in the community. The surveys were conducted between 2001 and 2012. Data analysis was performed from July 22, 2015, to December 12, 2016. The Composite International Diagnostic Interview was used to assess GAD along with comorbid disorders, role impairment, and help seeking. Respondents were 147 261 adults aged 18 to 99 years. The surveys had a weighted mean response rate of 69.5%. Across surveys, DSM-5 GAD had a combined lifetime prevalence (SE) of 3.7% (0.1%), 12-month prevalence of 1.8% (0.1%), and 30-day prevalence of 0.8% (0). Prevalence estimates varied widely across countries, with lifetime prevalence highest in high-income countries (5.0% [0.1%]), lower in middle-income countries (2.8% [0.1%]), and lowest in low-income countries (1.6% [0.1%]). Generalized anxiety disorder typically begins in adulthood and persists over time, although onset is later and clinical course is more persistent in lower-income countries. Lifetime comorbidity is high (81.9% [0.7%]), particularly with mood (63.0% [0.9%]) and other anxiety (51.7% [0.9%]) disorders. Severe role impairment is common across life domains (50.6% [1.2%]), particularly in high-income countries. Treatment is sought by approximately half of

  16. Cross-sectional epidemiology of hepatitis C virus detection and treatment in HIV-infected patients.

    PubMed

    Ena, Javier; Ruiz-de-Apodaca, Rosa F; Pasquau, Francisco; Amador, Concepción; Benito, Concepción

    2011-02-01

    Sustained virologic response to peginterferon plus ribavirin reduces liver-related complications and mortality in patients co-infected with HIV and hepatitis C virus. Therefore, the presence of any barriers to start hepatitis C virus therapy should be identified and eliminated in order to recruit all eligible patients. Cross-sectional study. In a HIV referral clinic we assessed the proportion of patients eligible for hepatitis C virus evaluation and treatment according to consensus guidelines. We identified 134 patients with hepatitis C virus and HIV co-infection. Twenty-one patients were excluded from the analysis due to never attending the HIV clinic (n=12) or having hepatitis C virus RNA not detectable (n=9). In the remaining 113 patients, only 61% had identification of hepatitis C virus genotype and quantification of hepatitis C viral load. Thirty-six patients started peginterferon plus ribavirin, and 16 (44%) achieved sustained virologic response. Seventy-seven patients did not receive treatment for hepatitis C virus due to the presence of medical contraindications (n=22), provider barriers (n=15), or patient barriers (n=40). Multivariate analysis identified lower education degree (odds ratio: 4.53; 95% confidence intervals: 1.36-15.16, p=0.014) and patient civil status single, separated or widower (odds ratio: 4.81; 95% confidence intervals: 1.54-14.99, p=0.007) as the independent determinants associated to not initiating therapy for hepatitis C virus infection in patients with barriers. A minor proportion of HIV-infected patients received appropriate assessment and treatment for hepatitis C virus infection. Social disadvantages require multidisciplinary models of health care to improve hepatitis C virus treatment initiation and success. Copyright © 2010 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  17. Epidemiology of cancers in Lahore, Pakistan, 2010–2012: a cross-sectional study

    PubMed Central

    Badar, Farhana; Mahmood, Shahid; Yusuf, Muhammed Aasim; Sultan, Faisal

    2016-01-01

    Objectives To estimate the population-level cancer estimates for the Lahore district, which is part of the Punjab Cancer Registry (PCR), Pakistan. The average population per year of Lahore was estimated at 9.8 million in 2010–2012. Design A cross-sectional study. Setting The Registry has 19 collaborating centres in Lahore that report their data to the Central Office located within a tertiary care cancer treatment facility in Lahore, Pakistan. Participants Patients belonging to Lahore, of any age-group, and diagnosed with cancer in 2010–2012, were included in the study. They were followed up between July and October 2015 to determine their vital status. Outcome measures Summaries were generated for gender, the basis of diagnosis, diagnoses and deaths. The Age-Standardized Incidence Rates (ASIR) were computed per 100 000 population, by gender and cancer site. Five-year age categories were created from 0–4 until 70–74, followed by 75+ years. Death counts were reported by site. Results Between 2010 and 2012, in Lahore, a total of 15 840 new cancers were diagnosed in 43% male patients and 57% female patients; 93.5% were microscopically confirmed and 6.5% non-microscopically. In females, the ASIR was 105.1 and in males, it was 66.7. ASIRs of leading cancers among women were breast 47.6, ovary 4.9 and corpus uteri 3.6, whereas among men they were prostate 6.4, bladder 5.0, and trachea, bronchus and lung 4.6. A total of 5134 deaths were recorded. Conclusions In Lahore, the ASIR was higher in women than in men. Among women and men, breast cancer and prostate cancer, respectively, were the leading cancer types. These estimates can be used for health promotion and policymaking in the region. PMID:27354082

  18. Epidemiology of cancers in Lahore, Pakistan, 2010-2012: a cross-sectional study.

    PubMed

    Badar, Farhana; Mahmood, Shahid; Yusuf, Muhammed Aasim; Sultan, Faisal

    2016-06-28

    To estimate the population-level cancer estimates for the Lahore district, which is part of the Punjab Cancer Registry (PCR), Pakistan. The average population per year of Lahore was estimated at 9.8 million in 2010-2012. A cross-sectional study. The Registry has 19 collaborating centres in Lahore that report their data to the Central Office located within a tertiary care cancer treatment facility in Lahore, Pakistan. Patients belonging to Lahore, of any age-group, and diagnosed with cancer in 2010-2012, were included in the study. They were followed up between July and October 2015 to determine their vital status. Summaries were generated for gender, the basis of diagnosis, diagnoses and deaths. The Age-Standardized Incidence Rates (ASIR) were computed per 100 000 population, by gender and cancer site. Five-year age categories were created from 0-4 until 70-74, followed by 75+ years. Death counts were reported by site. Between 2010 and 2012, in Lahore, a total of 15 840 new cancers were diagnosed in 43% male patients and 57% female patients; 93.5% were microscopically confirmed and 6.5% non-microscopically. In females, the ASIR was 105.1 and in males, it was 66.7. ASIRs of leading cancers among women were breast 47.6, ovary 4.9 and corpus uteri 3.6, whereas among men they were prostate 6.4, bladder 5.0, and trachea, bronchus and lung 4.6. A total of 5134 deaths were recorded. In Lahore, the ASIR was higher in women than in men. Among women and men, breast cancer and prostate cancer, respectively, were the leading cancer types. These estimates can be used for health promotion and policymaking in the region. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  19. Epidemiological features of alcohol use in rural India: a population-based cross-sectional study

    PubMed Central

    Shidhaye, Rahul

    2015-01-01

    Objectives We sought to estimate the proportion of adults in Sehore District, India, who consumed alcohol, and the proportion who had behaviours consistent with alcohol use disorders (AUDs), using the Alcohol Use Disorders Identification Test (AUDIT). Among men who drank, we identified individual-level, household-level and community-level factors associated with AUDIT scores. Men with AUDs (AUDIT score ≥8) reported on whether and where they had sought treatment, and about alcohol-related internal stigma. Design Population-based cross-sectional study. Setting Rural villages and urban wards in Sehore District, Madhya Pradesh, India. Participants n=3220 adult (≥18 years of age) residents of Sehore District. Primary outcome measure Score on the AUDIT. Results Nearly one in four men (23.8%) had consumed alcohol in the past 12 months, while few (0.6%) women were consumers. Among drinkers, 33.2% (95% CI 28.6% to 38.1%) had AUDIT scores consistent with hazardous drinking, 3.3% (95% CI 2.1% to 5.1%) with harmful drinking and 5.5% (95% CI 3.8% to 8.0%) with dependent drinking. We observed that AUDIT scores varied widely by village (intraclass correlation=0.052). Among men who had recently consumed alcohol, AUDIT scores were positively associated with depression, having at least one child, high-quality housing, urban residence, tobacco use and disability. AUDIT scores were negatively associated with land ownership, out-of-pocket healthcare expenditure and participation in the national employment programme. While 49.2% of men with AUDs felt embarrassed by their problems with alcohol, only 2.8% had sought treatment in the past 12 months. Conclusions A need exists for effectively identifying and treating adults with AUDs. Health promotion services, informed by commonly-expressed stigmatised beliefs held among those affected by AUDs and which are targeted at the most affected communities, may be an effective step in closing the treatment gap. PMID:26685035

  20. The epidemiology of chronic pain in Libya: a cross-sectional telephone survey.

    PubMed

    Elzahaf, Raga A; Johnson, Mark I; Tashani, Osama A

    2016-08-11

    Chronic pain is a public health problem although there is a paucity of prevalence data from countries in the Middle East and North Africa. The aim of this study was to estimate the prevalence of chronic pain and neuropathic pain in a sample of the general adult population in Libya. A cross-sectional telephone survey was conducted before the onset of the Libyan Civil War (February 2011) on a sample of self-declared Libyans who had a landline telephone and were at least 18 years of age. Random sampling of household telephone number dialling was undertaken in three major cities and interviews conducted using an Arabic version of the Structured Telephone Interviews Questionnaire on Chronic Pain previously used to collect data in Europe. In addition, an Arabic version of S-LANSS was used. 1212 individuals were interviewed (response rate = 95.1 %, mean age = 37.8 ± 13.9 years, female = 54.6 %). The prevalence of chronic pain ≥ 3 months was 19.6 % (95 % CI 14.6 % to 24.6 %) with a mean ± SD duration of pain of 6 · 5 ± 5 · 7 years and a higher prevalence for women. The prevalence of neuropathic pain in the respondents reporting chronic pain was 19 · 7 % (95 % CI 14 · 6-24 · 7), equivalent to 3 · 9 % (95 % CI 2 · 8 to 5 · 0 %) of the general adult population. Only, 71 (29 · 8 %) of respondents reported that their pain was being adequately controlled. The prevalence of chronic pain in the general adult population of Libya was approximately 20 % and comparable with Europe and North America. This suggests that chronic pain is a public health problem in Libya. Risk factors are being a woman, advanced age and unemployment. There is a need for improved health policies in Libya to ensure that patients with chronic pain receive effective management.

  1. Gender-specific epidemiology of diabetes: a representative cross-sectional study

    PubMed Central

    Grant, Janet F; Hicks, Neville; Taylor, Anne W; Chittleborough, Catherine R; Phillips, Patrick J

    2009-01-01

    Background Diabetes and its associated complications are part of a chronic disease global epidemic that presents a public health challenge. Epidemiologists examining health differences between men and women are being challenged to recognise the biological and social constructions behind the terms 'sex' and/or 'gender', together with social epidemiology principles and the life course approach. This paper examines the epidemiology of a population with diabetes from the north-west metropolitan region of South Australia. Methods Data were used from a sub-population with diabetes (n = 263), from 4060 adults aged 18 years and over living in the north-west suburbs of Adelaide, South Australia. Eligible respondents were asked to participate in a telephone interview, a self-report questionnaire and a biomedical examination. Diabetes (undiagnosed and diagnosed) was determined using self-reported information and a fasting blood test administered to participants. Data were analysed using SPSS (Version 10.0) and EpiInfo (Version 6.0). Results Factors associated with diabetes for both men and women were being aged 40 years and over, and having a low gross annual household income, obesity and a family history of diabetes. In addition, being an ex-smoker and having low cholesterol levels were associated with diabetes among men. Among women, having a high waist-hip ratio, high blood pressure and reporting a previous cardiovascular event or mental health problem were associated with diabetes. Conclusion The results found that men and women with diabetes face different challenges in the management of their condition. Public health implications include a need for quality surveillance data, including epidemiological life course, social, behavioural, genetic and environmental factors. This will enrich the evidence base for health promotion professionals and allow policy makers to draw inferences and conclusions for interventions and planning purposes. PMID:19284598

  2. Respiratory diseases among agricultural industry workers in India: a cross-sectional epidemiological study.

    PubMed

    Singh, A B; Singh, A; Pandit, T

    1999-01-01

    Epidemiological survey for respiratory diseases among agricultural industry workers, such as bakeries, poultry farms, granaries and a sugar refinery was carried out using a medical questionnaire on various respiratory symptoms such as cough, breathlessness, rhinitis. The questionnaire was filled up by two doctoral students during personal visits to these work environments. The survey revealed that 40-59% of workers in different occupational work environments suffered from one or more respiratory ailments. As much as 36-40% of the workers reported work-related symptoms which is close to similar data from Western countries. A higher incidence of respiratory disorders was recorded in workers with longer duration of employment. Older workers suffered more than the young ones. Family history of atopy was found to have least effect on the incidence of cough, breathlessness and rhinitis in the workers. Smoking was found to have definite impact on the incidence of cough and breathlessness

  3. Prevalence of urinary incontinence in community dwelling men: a cross sectional nationwide epidemiological survey.

    PubMed

    Diokno, Ananias C; Estanol, Maria Victoria C; Ibrahim, Ibrahim Awad; Balasubramaniam, Mamtha

    2007-01-01

    Epidemiological studies on urinary incontinence (UI) in adult men of all ages are scarce. We aim to describe the UI phenomenon among community dwelling adult males in the United States (US). We analyzed data from male respondents to a 14-item mailed UI symptoms questionnaire to the National Family Opinion (NFO) World Group Panel of 45,000 households matching the US 2000 census population on five key demographic elements. A total of 29,903 households responded, of which 21,590 were male heads of household (mean age 50 +/-15.2 years old). A total of 2,059 men (12.7%) reported symptoms of UI during the last 30 days. Symptoms of urge urinary incontinence (UUI), stress urinary incontinence (SUI), mixed urinary incontinence (MUI) symptoms, and other types of urinary incontinence (OUI) symptoms, were reported by 44.6%, 24.5%, 18.8%, and 12.3%, respectively. Among those with UI symptoms, the proportion of UUI and MUI symptoms increases with age while SUI symptoms decrease as age increases. Of those with UI symptoms, 44% consulted a physician of whom 57% did so within 6 months of the onset of symptoms. Treatments reported included absorbent pads (48%), prescription medication (30%), surgical procedure (18%), and intermittent catheterization (4%). Almost 1 in 10 males reported symptoms of UI. The UI prevalence rate increases with age and UUI symptoms is the most prevalent type reported. Less than half of men with UI symptoms sought professional help and half of them did so within 6 months of onset of UI symptoms.

  4. Changing Epidemiology of Common Cancers in Southern Iran, 2007-2010: A Cross Sectional Study

    PubMed Central

    Masoompour, Seyed Masoom; Lankarani, Kamran B.; Honarvar, Behnam; Tabatabaee, Seyed Hamidreza; Moghadami, Mohsen; Khosravizadegan, Zahra

    2016-01-01

    We have evaluated the ever changing epidemiology of cancers in Fars province, Iran since the re-establishment of Fars cancer registry. Based on the collected data from all related sources in Fars province from 2007–2010 we calculated the cancer age-standardized rates per 100,000 person-years (ASRs). The results are presented as incidence rates of cases by site according to the International Classification of Diseases for Oncology (ICD-O), sex, age, crude rate, and ASRs. In women the total ASR was 41.70 per 100,000 from 1985–1989 which had increased to 55.50 and 95.46 during 1998–2002 and 2007–2010. The incidence of breast cancer in women during 2007–2010 was about two and four times higher than 1998–2002 and 1985–1989. The incidence of colorectal cancer in women during 2007–2010 was about three and five times higher than 1998–2002 and 1985–1989. In men the total ASR was 62.9 per 100,000 in 1985–1989 that increased to 64.50 and 101.48 during 1998–2002 and 2007–2010. Although stomach cancer was the most common cancer among men during 1985–1989 and 1998–2002, but in recent study bladder cancer was the most common cancer among men in Fars province. The incidence of colorectal cancer in men during 2007–2010 was about three times higher than 1998–2002 and 1985–1989. This study shows growing incidence of cancer in southern Iran. The colorectal cancer in both genders had increased and its pattern is similar to western countries. In men, bladder and prostate cancers had a growing rate and the incidences of these cancers in the present study were greater than stomach cancer. PMID:27219458

  5. Epidemiology and awareness of hypertension in a rural Ugandan community: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Hypertension is one of the largest causes of preventable morbidity and mortality worldwide. There are few population-based studies on hypertension epidemiology to guide public health strategies in sub-Saharan Africa. Using a community-based strategy that integrated screening for HIV and non-communicable diseases, we determined the prevalence, awareness, treatment rates, and sociodemographic factors associated with hypertension in rural Uganda. Methods A household census was performed to enumerate the population in Kakyerere parish in Mbarara district, Uganda. A multi-disease community-based screening campaign for hypertension, diabetes, and HIV was then conducted. During the campaign, all adults received a blood pressure (BP) measurement and completed a survey examining sociodemographic factors. Hypertension was defined as elevated BP (≥140/≥90 mmHg) on the lowest of three BP measurements or current use of antihypertensives. Prevalence was calculated and standardized to age distribution. Sociodemographic factors associated with hypertension were evaluated using a log-link Poisson regression model with robust standard errors. Results Community participation in the screening campaign was 65%, including 1245 women and 1007 men. The prevalence of hypertension was 14.6%; awareness of diagnosis (38.1%) and current receipt of treatment (20.6%) were both low. Age-standardized to the WHO world standard population, hypertension prevalence was 19.8%, which is comparable to 21.6% in the US and 18.4% in the UK. Sociodemographic factors associated with hypertension included increasing age, male gender, overweight, obesity, diabetes, alcohol consumption, and family history. Prevalence of modifiable factors was high: 28.3% women were overweight/obese and 24.1% men consumed ≥10 alcoholic drinks per month. Conclusions We found a substantial burden of hypertension in rural Uganda. Awareness and treatment of hypertension is low in this region. Enhanced community

  6. Epidemiology of Traumatic Injuries in the Northeast Region of Haiti: A Cross-sectional Study.

    PubMed

    Aluisio, Adam R; De Wulf, Annelies; Louis, Ambert; Bloem, Christina

    2015-12-01

    More than 90% of traumatic morbidity and mortality occurs in low- and middle-income countries (LMIC). Haiti is the poorest country in the Western Hemisphere and lacks contemporary statistics on the epidemiology of traumatic injuries. This study aimed to characterize the burden of traumatic injuries among emergency department patients in the Northeast region of Haiti. Data were collected from the emergency departments of all public hospitals in the Northeast region of Haiti, which included the Fort Liberté, Ouanaminthe, and Trou du Nord sites. All patients presenting for emergent care of traumatic injuries were included. Data were obtained via review of emergency department registries and patient records from October 1, 2013 through November 30, 2013. Data on demographics, mechanisms of trauma, and anatomical regions of injury were gathered using a standardized tool and analyzed using descriptive statistics. Temporal analysis of injury frequency was explored using regression modeling. Data from 383 patient encounters were accrued. Ouanaminthe Hospital treated the majority of emergent injuries (59.3%), followed by Fort Liberté (30.3%) and Trou du Nord (10.4%). The median age in years was 23 with 23.1% of patients being less than 15 years of age. Road traffic accidents (RTAs) and interpersonal violence accounted for 65.8% and 30.1% of all traumatic mechanisms, respectively. Extremity trauma was the most frequently observed anatomical region of injury (38.9%), followed by head and neck (30.3%) and facial (19.1%) injuries. Trauma due to RTA resulted in a single injury (83.8%) to either an extremity or the head and neck regions most frequently. A minority of patients had medical record documentation (37.9%). Blood pressure, respiratory rate, and mental status were documented in 19.3%, 4.1%, and 0.0% of records, respectively. There were 6.3 injuries/day during the data collection period with no correlation between the frequency of emergent trauma cases and day of the

  7. Profiling of smokers and snuffers among young Finnish men - cross-sectional epidemiological study().

    PubMed

    Päkkilä, Jari; Anttonen, Vuokko; Patinen, Pertti; Nyman, Kai; Valkeapää, Kirsi; Birkhed, Dowen; Tjäderhane, Leo; Tanner, Tarja

    2017-08-08

    The purpose of this study was to get new information from several sources about the background factors of Finnish smokers, snuffers, and dual users. Profiles of young smokers and snuffers were investigated in association with restorative treatment need, oral hygiene, eating habits, physical activity, body mass index (BMI), psychological and socioeconomic factors. The study group comprised 3420 conscripts. The data were collected from four different sources: a health examination including an oral health screening, a computer-based questionnaire for investigating individual background factors, a psychological test assessing cognitive skills, and the Cooper test. Statistical analyses comprised cross tabulation and binary logistic regression modelling. The odds for smoking were the greatest among those who had DT (Decayed teeth) > 0, used energy drinks or alcohol regularly, or whose parents were divorced. A score of ≥2900 m in the Cooper test, a higher physical exercise level, a higher own education level, and using sports drinks decreased the odds for smoking. The odds for snuffing were higher among those who ran >2500 m in the Cooper test, had a BMI of ≥25, used sports/energy drinks, or exercised regularly, and lower among those who achieved good results in the cognitive test. Using energy/sports drinks or alcohol was positively and a higher education level was negatively associated with dual use. Along with increasing prevalence of snuffing, heterogeneity is likely among snuffers. Good cognitive skills may prevent from smoking and snuffing.

  8. Physical diability after retirement and occupational risk factors during working life: a cross sectional epidemiological study in the Paris area.

    PubMed Central

    Cassou, B; Derriennic, F; Iwatsubo, Y; Amphoux, M

    1992-01-01

    STUDY OBJECTIVE--The aim was to examine the relationship between exposure to occupational risk factors during working life and physical disability after retirement. DESIGN--The study was a cross sectional epidemiological survey of a representative sample of retired subjects belonging to a supplementary pension fund in the Paris area. SETTING--The study took place in the general community. PATIENTS--307 men and 320 women (63.1% of those approached) answered a questionnaire during home interviews. Their average age was 69 (SD4) years at the beginning of the survey. Whether or not subjects had been exposed to occupational risks was determined from their statements concerning the presence or absence of eight harmful environmental conditions while at work. Physical disability was defined as difficulty in carrying out seven basic activities of daily life. MAIN RESULTS--The results of univariate analyses showed significant relationships between exposure during working life to occupational risks including noise, heat, dust, carrying heavy loads, and awkward postures on the one hand, and the presence of a physical disability after retirement on the other. Multivariate analysis based on logistic regression models that took account of age, sex, and health impairments revealed a specific link between exposure to carrying heavy loads and physical disability after retirement. CONCLUSIONS--These results suggest that occupational risk factors might be important in determining such disability in retired people. PMID:1479320

  9. Aleutian mink disease virus in free-ranging mustelids in Finland - a cross-sectional epidemiological and phylogenetic study.

    PubMed

    Knuuttila, A; Aaltonen, K; Virtala, A-M K; Henttonen, H; Isomursu, M; Leimann, A; Maran, T; Saarma, U; Timonen, P; Vapalahti, O; Sironen, T

    2015-06-01

    Aleutian mink disease virus (AMDV) can cause severe immune-complex-mediated disease in American mink. AMDV has also been detected in several other mustelid species with potential negative impact on their health and population. A molecular and cross-sectional epidemiological study was conducted to obtain data on the prevalence, distribution, transmission and diversity of AMDV strains in Finnish free-ranging mustelids and risk factors associated with infection. The presence of anti-AMDV antibodies and/or AMDV DNA was tested from 308 samples representing eight mustelid species and 17 administrative regions. Positive samples were detected across Finland, and in 54 % (31/57) of feral American mink, 27 % (7/26) of European badgers and 7 % (1/14) of European polecats. Samples from Eurasian otters, European pine martens, least weasels, stoat and wolverine were negative. Major risk factors for infection were the species American mink with 335 and badger with 74 times higher odds than other species, and the years 2006-2009 with five times higher odds than the years 2010-2014. No clustering according to species, geographical origin or year was evident in phylogeny, except for four divergent sequences from Estonian badgers that formed a separate phylogroup distinct from other AMDV strains. This study showed that AMDV was prevalent in certain species of Finnish free-ranging mustelids and widely distributed across Finland. Furthermore, the free-ranging mustelids carried both strains similar to those found in farmed mink, but also distinct strains that may represent novel amdoparvoviruses.

  10. The Sero-epidemiology of Coxiella burnetii in Humans and Cattle, Western Kenya: Evidence from a Cross-Sectional Study

    PubMed Central

    Thomas, Lian F.; Cook, Elizabeth A. J.; de Glanville, William A.; Atkinson, Peter M.; Wamae, Claire N.; Fèvre, Eric M.

    2016-01-01

    Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever) is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover). Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead) and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material) was also a risk

  11. The Sero-epidemiology of Coxiella burnetii in Humans and Cattle, Western Kenya: Evidence from a Cross-Sectional Study.

    PubMed

    Wardrop, Nicola A; Thomas, Lian F; Cook, Elizabeth A J; de Glanville, William A; Atkinson, Peter M; Wamae, Claire N; Fèvre, Eric M

    2016-10-01

    Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever) is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover). Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead) and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material) was also a risk

  12. A multi-national European cross-sectional study of feline calicivirus epidemiology, diversity and vaccine cross-reactivity.

    PubMed

    Afonso, Maria M; Pinchbeck, Gina L; Smith, Shirley L; Daly, Janet M; Gaskell, Rosalind M; Dawson, Susan; Radford, Alan D

    2017-05-09

    Feline calicivirus (FCV) is an important pathogen of cats for which vaccination is regularly practised. Long-term use of established vaccine antigens raises the theoretical possibility that field viruses could become resistant. This study aimed to assess the current ability of the FCV-F9 vaccine strain to neutralise a randomly collected contemporary panel of FCV field strains collected prospectively in six European countries. Veterinary practices (64) were randomly selected from six countries (UK, Sweden, Netherlands, Germany, France and Italy). Oropharyngeal swabs were requested from 30 (UK) and 40 (other countries) cats attending each practice. Presence of FCV was determined by virus isolation, and risk factors for FCV shedding assessed by multivariable logistic regression. Phylogenetic analyses were used to describe the FCV population structure. In vitro virus neutralisation assays were performed to evaluate FCV-F9 cross-reactivity using plasma from four vaccinated cats. The overall prevalence of FCV was 9.2%. Risk factors positively associated with FCV shedding included multi-cat households, chronic gingivostomatitis, younger age, not being neutered, as well as residing in certain countries. Phylogenetic analysis showed extensive variability and no countrywide clusters. Despite being first isolated in the 1950s, FCV-F9 clustered with contemporary field isolates. Plasma raised to FCV-F9 neutralized 97% of tested isolates (titres 1:4 to 1:5792), with 26.5%, 35.7% and 50% of isolates being neutralized by 5, 10 and 20 antibody units respectively. This study represents the largest prospective analysis of FCV diversity and antigenic cross-reactivity at a European level. The scale and random nature of sampling used gives confidence that the FCV isolates used are broadly representative of FCVs that cats are exposed to in these countries. The in vitro neutralisation results suggest that antibodies raised to FCV-F9 remain broadly cross-reactive to contemporary FCV

  13. Epidemiology of colorectal cancer in Turkey: A cross-sectional disease registry study (A Turkish Oncology Group trial).

    PubMed

    Aykan, Nuri Faruk; Yalçın, Suayib; Turhal, N Serdar; Özdoğan, Mustafa; Demir, Gökhan; Özkan, Metin; Yaren, Arzu; Camcı, Celalettin; Akbulut, Hakan; Artaç, Mehmet; Meydan, Nezih; Uygun, Kazim; Işıkdoğan, Abdurrahman; Ünsal, Diclehan; Özyılkan, Özgür; Arıcan, Ali; Seyrek, Ertuğrul; Tekin, Salim Başol; Manavoğlu, Osman; Özet, Ahmet; Elkıran, Tamer; Dişçi, Rian

    2015-03-01

    This study aimed to determine the epidemiological characteristics of colorectal cancer in Turkey. In this multicenter, prospective, and cross-sectional registry study, data for 968 patients with colorectal cancer from 21 centers in 7 geographic regions were analyzed. Diagnosis was colon cancer in 662 (68.4%) and rectum cancer in 306 (31.6%) patients. In total, 60.9% of patients was male; mean age was 58.9±12.6 years. Among patients, 15.0% was drinking alcohol, 17.5% was smoking, 1.5% had familial history of polyposis, 15.0% had diabetes mellitus, 1.0% had inflammatory bowel disease. Fruit and vegetable consumption was low (<3 times/week) in 35.5% and red meat consumption was high (≥3 times/week) in 47.4% of the patients. Median time-to diagnosis was 3.0 months and 4.0 months for patients with colon and rectum cancer, respectively. Mean body mass index was >25 in all group of patients. Distal rectum (61.3%) and sigmoid colon (36.8%) were the most common locations of cancer, for rectum and colon respectively. In total, 85.6% of patients were operated; 25.8% had emergency surgery. Low anterior resection rate was 64.2% in rectum cancer. In majority (89.8%) of the patients with rectum cancer who received preoperative treatment, conventional chemo-radiotherapy regimen was given. pTNM staging at diagnosis showed that stage III and IV patients were in majority (35.9% and 29.7%, respectively). Colon cancer is more frequent than rectum cancer in Turkey. Colorectal cancer patients are diagnosed at later stages. Most of the cases were operated. Interregional differences for risk factors are worthwhile for evaluation in future trials.

  14. Epidemiological association between body fat percentage and cervical cancer: a cross-sectional population-based survey from Mexico.

    PubMed

    López-Hernández, Daniel

    2013-08-01

    Various studies have reported a direct association of cervical cancer risk with obesity and weight but not with the body fat percentage (BFP). The aim of this study was to analyze various anthropometric measures as potential risk factors for cervical cancer. A total of 20,236 women were included in a cross-sectional population-based survey. Obesity was defined according to the World Health Organization criteria, and central obesity was ≥80 cm; the BFP was defined using the Deurenberg equation (BFP = 1.2 [BMI] + 0.23 [age] - 10.8 [sex] - 5.4). The odds ratio (OR) was estimated from the chi square test and logistic regression models. The prevalence of cervical cancer increased from 514 (95% confidence interval [CI] 321, 707) and 680 (95% CI 494, 866) to 732 (95% CI 535, 928) per 100,000 inhabitants in subjects with a normal weight, subjects who were overweight and subjects who were obese, respectively. Moreover, an association between cervical cancer and BFP (OR 1.027; CI 95% 1.006, 1.048; p = 0.012) was observed, and the risk increased with a BFP ≥45% (OR 2.369; CI 95% 1.284, 4.369; p = 0.006). These data suggest a trend between the body mass index and the increasing prevalence of cervical cancer. In addition, the data showed a significant association between the BFP and cervical cancer, and this epidemiological association was higher as the BFP increased. Copyright © 2013 IMSS. Published by Elsevier Inc. All rights reserved.

  15. Epidemiological perspectives of ticks and tick-borne diseases in South Sudan: cross-sectional survey results.

    PubMed

    Kivaria, Fredrick M; Kapaga, Angolwisye M; Mbassa, Gabriel K; Mtui, Paul F; Wani, Rhombe J

    2012-09-03

    A cross-sectional study was conducted between September and October 2010 in five states of South Sudan that were selected on the basis of the perceived risk of tick-borne diseases. The purpose was to investigate epidemiological parameters of tick-borne diseases in South Sudan and their uses in future control strategies. A total of 805 calves were assessed by clinical, microscopic and serological examination and tick counts. The indirect Enzyme-Linked Immuno-Sorbent Assay (ELISA) was used to detect antibodies to Theileria parva, Theileria mutans, Anaplasma marginale and Babesian bigemina. Sero-conversion risks for T. parva and T. mutans were 27.3% and 31.3% respectively, whilst the risk was 57.6% and 52.8% for A. marginale and B. bigemina, respectively. Major tick species identified include Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus microplus, Amblyomma variegatum, and Rhipicephalus evertsi. There was great variation (P ≤ 0.001) in the number of all these ticks, both between herds in a state and between calves in an individual herd. The low and intermediate sero-conversion risks observed in the study states suggest that immunisation against East Coast fever (ECF) is justified. Fortunately, three major genotypes that were identified by applying Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCRRFLP) analysis on the p104 to the blood samples and T. parva Muguga, matched very well with T. parva Kiambu 5 and T. parva Muguga; therefore the Muguga cocktail can be used for the immunisation of cattle in South Sudan. However, prospective studies are required to develop optimal control measures for tick-borne diseases under different ecological and husbandry practices in South Sudan.

  16. Cultural epidemiology of pandemic influenza in urban and rural Pune, India: a cross-sectional, mixed-methods study

    PubMed Central

    Sundaram, Neisha; Schaetti, Christian; Purohit, Vidula; Kudale, Abhay; Weiss, Mitchell G

    2014-01-01

    Objective To identify and compare sociocultural features of pandemic influenza with reference to illness-related experience, meaning and behaviour in urban and rural areas of India. Design Cross-sectional, mixed-methods, cultural epidemiological survey with vignette-based interviews. Semistructured explanatory model interviews were used to study community ideas of the 2009 influenza pandemic. In-depth interviews elaborated respondents’ experience during the pandemic. Setting Urban and rural communities, Pune district, western India. Participants Survey of urban (n=215) and rural (n=221) residents aged between 18 and 65 years. In-depth interviews of respondents with a history of 2009 pandemic influenza (n=6). Results More urban (36.7%) than rural respondents (16.3%, p<0.001) identified the illness in the vignette as ‘swine flu’. Over half (56.7%) believed the illness would be fatal without treatment, but with treatment 96% predicted full recovery. Worry (‘tension’) about the illness was reported as more troubling than somatic symptoms. The most common perceived causes—‘exposure to a dirty environment’ and ‘cough or sneeze of an infected person’–were more prominent in the urban group. Among rural respondents, climatic conditions, drinking contaminated water, tension and cultural ideas on humoral imbalance from heat-producing or cold-producing foods were more prominent. The most widely reported home treatment was herbal remedies; more rural respondents suggested reliance on prayer, and symptom relief was more of a priority for urban respondents. Government health services were preferred in the urban communities, and rural residents relied more than urban residents on private facilities. The important preventive measures emphasised were cleanliness, wholesome lifestyle and vaccines, and more urban respondents reported the use of masks. In-depth interviews indicated treatment delays during the 2009 pandemic, especially among rural patients

  17. Geographic epidemiology of cardiometabolic risk factors in middle class urban residents in India: cross-sectional study.

    PubMed

    Gupta, Rajeev; Sharma, Krishna Kumar; Gupta, Bal Kishan; Gupta, Arvind; Saboo, Banshi; Maheshwari, Anuj; Mahanta, Tulika; Deedwania, Prakash C

    2015-06-01

    To determine epidemiology of cardiovascular risk factors according to geographic distribution and macrolevel social development index among urban middle class subjects in India. We performed cross-sectional surveys in 11 cities in India during years 2005-2009. 6198 subjects aged 20-75 years (men 3426, women 2772, response 62%) were evaluated for cardiovascular risk factors. Cities were grouped according to geographic distribution into northern (3 cities, n = 1321), western (2 cities, n = 1814), southern (3 cities, n = 1237) and eastern (3 cities, n = 1826). They were also grouped according to human social development index into low (3 cities, n = 1794), middle (5 cities, n = 2634) and high (3 cities, n = 1825). Standard definitions were used to determine risk factors. Differences in risk factors were evaluated using χ(2) test. Trends were examined by least squares regression. Age-adjusted prevalence (95% confidence intervals) of various risk factors was: low physical activity 42.1% (40.9-43.3), high dietary fat 49.9% (47.8-52.0), low fruit/vegetables 26.9% (25.8-28.0), smoking 10.1% (9.1-11.1), smokeless tobacco use 9.8% (9.1-10.5), overweight 42.9% (41.7-44.1), obesity 11.6% (10.8-12.4), high waist circumference 45.5% (44.3-46.7), high waist-hip ratio 75.7% (74.7-76.8), hypertension 31.6% (30.4-32.8), hypercholesterolemia 25.0% (23.9-26.9), low HDL cholesterol 42.5% (41.3-43.7), hypertriglyceridemia 36.9% (35.7-38.1), diabetes 15.7% (14.8-16.6), and metabolic syndrome 35.7% (34.5-36.9). Compared with national average, prevalence of most risk factors was not significantly different in various geographic regions, however, cities in eastern region had significantly lower prevalence of overweight, hypertension, hypercholesterolemia, diabetes and metabolic syndrome compared with other regions (P < 0.05 for various comparisons). It was also observed that cities with low human social development index had lowest prevalence of these risk

  18. Seroprevalence of Bordetella pertussis antibodies in adults in Hungary: results of an epidemiological cross-sectional study.

    PubMed

    Torzsa, Péter; Devadiga, Raghavendra; Tafalla, Monica

    2017-04-04

    Pertussis (whooping cough) is well known to be underreported, particularly among adults, who can act as an infectious reservoir, potentially putting susceptible newborns at risk of serious illness. The purpose of this study was to estimate the seroprevalence of pertussis in adults in Hungary. This epidemiological, cross-sectional study was conducted in adults in five general practitioners' practices in Hungary. Serum anti-pertussis toxin immunoglobulin G (anti-PT IgG) antibody levels were analyzed using enzyme-linked immunosorbent assay. Sera were classified following manufacturer's instructions as: strongly indicative of current/recent infection (≥1.5 optical density [OD] units); indicative of current/recent infection (≥1.0 OD units); seropositive (>0.3 OD units); or seronegative (≤0.3 OD units). Logistic regression was performed to describe the associations between seroprevalence and various characteristics. Between 24(th) April 2014 and 24(th) April 2015, 1999 adults (60.6% female; mean age 47.4 ± 17.7 years) were included in the analysis. A total of 14.8% were seropositive for anti-PT IgG, 1.1% had a level indicative of current/recent infection, and 0.1% had a level strongly indicative of current/recent infection. Logistic regression showed significant relationships between increased rates of seropositivity and: age ≥60 years (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.39-2.80; p = .0002) or 18-29 years (OR, 1.67; 95% CI, 1.13-2.46; p = .0094) vs. 45-59 years; former smoker (OR, 1.46; 95% CI, 1.08-1.97; p = .014) or current smoker (OR, 1.38; 95% CI, 1.01-1.89; p = .045) vs. never smoker; and male (OR, 1.30; 95% CI, 1.01-1.68; p = .041) vs. female. Also, between increased rates of probable current/recent infection and current smoker (OR, 7.50; 95% CI, 2.32-24.31; p = .0008) or former smoker (OR, 4.07; 95% CI, 1.21-13.64; p = .023) vs. never smoker. Approximately 85% of the adults studied were seronegative and therefore

  19. Jet inclusive cross sections

    SciTech Connect

    Del Duca, V.

    1992-11-01

    Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons.

  20. Neutron cross sections

    SciTech Connect

    Not Available

    1988-01-01

    This handbook displays curves of neutron cross sections in the energy range of 0.01 eV to 200 MeV (and associated information) as a function of incident neutron energy. Tables include reference to all data. Information on isomeric state production is also included. This book represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, the third edition of which was published in 1976.

  1. Understanding the epidemiology of avoidable significant harm in primary care: protocol for a retrospective cross-sectional study

    PubMed Central

    Bell, Brian G; Campbell, Stephen; Carson-Stevens, Andrew; Evans, Huw Prosser; Cooper, Alison; Sheehan, Christina; Rodgers, Sarah; Johnson, Christine; Edwards, Adrian; Armstrong, Sarah; Mehta, Rajnikant; Chuter, Antony; Donnelly, Ailsa; Ashcroft, Darren M; Lymn, Joanne; Smith, Pam; Sheikh, Aziz; Boyd, Matthew; Avery, Anthony J

    2017-01-01

    Introduction Most patient safety research has focused on specialist-care settings where there is an appreciation of the frequency and causes of medical errors, and the resulting burden of adverse events. There have, however, been few large-scale robust studies that have investigated the extent and severity of avoidable harm in primary care. To address this, we will conduct a 12-month retrospective cross-sectional study involving case note review of primary care patients. Methods and analysis We will conduct electronic searches of general practice (GP) clinical computer systems to identify patients with avoidable significant harm. Up to 16 general practices from 3 areas of England (East Midlands, London and the North West) will be recruited based on practice size, to obtain a sample of around 100 000 patients. Our investigations will include an ‘enhanced sample’ of patients with the highest risk of avoidable significant harm. We will estimate the incidence of avoidable significant harm and express this as ‘per 100 000 patients per year’. Univariate and multivariate analysis will be conducted to identify the factors associated with avoidable significant harm. Ethics/Dissemination The decision regarding participation by general practices in the study is entirely voluntary; the consent to participate may be withdrawn at any time. We will not seek individual patient consent for the retrospective case note review, but if patients respond to publicity about the project and say they do not wish their records to be included, we will follow these instructions. We will produce a report for the Department of Health's Policy Research Programme and several high-quality peer-reviewed publications in scientific journals. The study has been granted a favourable opinion by the East Midlands Nottingham 2 Research Ethics Committee (reference 15/EM/0411) and Confidentiality Advisory Group approval for access to medical records without consent under section 251 of the NHS

  2. [Comparability of studies of epidemiological research on aging : Results from the Longitudinal Urban Cohort Ageing Study (LUCAS) and three representative Hamburg cross-sectional studies of healthy aging].

    PubMed

    Dapp, Ulrike; Dirksen-Fischer, Martin; Rieger-Ndakorerwa, Gudrun; Fertmann, Regina; Stender, Klaus-Peter; Golgert, Stefan; von Renteln-Kruse, Wolfgang; Minder, Christoph E

    2016-05-01

    Participants of the Longitudinal Urban Cohort Ageing Study (LUCAS) were recruited from patients 60 years and older from general practitioner's offices in Hamburg. This is different from the usual methods of drawing representative samples. The research question addressed the comparability of LUCAS results with those from cross-sectional surveys with participants randomly chosen from a population list. Therefore, the LUCAS data collected in four waves during the first 12 years were compared with data (age, gender) from the Hamburg Statistics Office (HSO), and selected characteristics (socio-demography, health, mobility) from three representative cross-sectional surveys in older Hamburg citizens. First, HSO data compiled in population pyramids for older men and women were compared with equivalent pyramids based on the LUCAS data at recruitment (2000/01) and in waves 2 to 4. Second, characteristics worded identically in the cross-sectional surveys and the simultaneous LUCAS waves were compared. The LUCAS population pyramids were in good accordance at all time points with those of the general older population in Hamburg (except ages 60-64 in men in 2000). Good comparability was also found for health related characteristics from the three representative studies and simultaneous LUCAS waves (e. g. need of nursing care in 2012: LUCAS 7.1 %; Hamburg 7.4 %). Information on health in old age generated periodically in the LUCAS cohort was largely comparable with that from representative cross-sectional studies and statistics registries. Older people are frequently under-represented in epidemiological studies. Therefore, the LUCAS data may provide useful information for Hamburg and similar metropolitan areas in Germany.

  3. Cross-sectional studies published in Indian journal of community medicine: evaluation of adherence to strengthening the reporting of observational studies in epidemiology statement.

    PubMed

    Jeelani, A; Malik, Wr; Haq, I; Aleem, S; Mujtaba, M; Syed, N

    2014-11-01

    The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement is a set of recommendations about what should be included in a more accurate and complete description of observational studies. The aim was to assess the quality of reporting of cross-sectional studies by evaluating the extent to which they adhere to the STROBE statement. This study has a cross-sectional design. All the articles published as original articles in Indian Journal of Community Medicine from January 2010 to September 2011 were downloaded from the journal website. A total of 96 articles were downloaded out of which 80 were found to have a cross-sectional design. Variables were: (1) Percentage of STROBE items included in a report and (2) percentage of articles reporting each item in the STROBE checklist. Data analysis was done by descriptive statistics using frequencies and percentages. A total of 80 articles were evaluated. About 46% (37/80) articles reported 12-15 items of the STROBE checklist. Bias, nonparticipants and reasons for nonparticipation, other analyses done, generalizability, and source of funding were reported by < 25% of studies. The most frequently reported items of the checklist were summary of what was done and what was found in the abstract, background/rationale, objectives, setting, outcome data, key results in discussion, interpretation of results. None of the articles reported all items of the STROBE checklist. This study reveals that the quality of reporting cross-sectional studies in Indian Journal of Community Medicine is not satisfactory and there is room for improvement.

  4. Epidemiology of rheumatic diseases in Mixtec and Chontal indigenous communities in Mexico: a cross-sectional community-based study.

    PubMed

    Julián-Santiago, Flor; García-García, Conrado; García-Olivera, Imelda; Goycochea-Robles, María Victoria; Pelaez-Ballestas, Ingris

    2016-07-01

    This study aimed to estimate the prevalence of musculoskeletal (MSK) disorders and rheumatic diseases in the Chontal and Mixtec indigenous communities in the state of Oaxaca, Mexico, using the Community-Oriented Program for the Control of Rheumatic Diseases (COPCORD) methodology. After cross-culturally validating the COPCORD questionnaire for these communities, we conducted a cross-sectional, analytical, community-based census study using a house-to-house method. Positive cases of MSK disorders were assessed by primary care physicians and rheumatologists. The study population included participants aged ≥18 years from the indigenous communities of San Antonio Huitepec and San Carlos Yautepec. A total of 1061 persons participated in the study. Mean age was 46.9 years (standard deviation 19.9; age range 18-97 years); 642 (60.5 %) were women; 483 participants (45.5; 42.4-48.5 %) had MSK pain in the previous 7 days. Diagnoses were back pain 170 (16.0 %; 95 % confidence interval [CI] 13.8-18.3); osteoarthritis 157 (14.7 %; 95 % CI 12.7-17.0); rheumatic regional pain syndrome 53 (4.9 %; 95 % CI 3.7-6.4); rheumatoid arthritis 4 (0.3 %; 95 % CI 0.1-0.9); dermatomyositis 1 (0.09 %; 95 % CI 0.0-0.5); ankylosing spondylitis 1 (0.09 %; 95 % CI 0.0-0.5); systemic lupus erythematosus 1 (0.09 %; 95 % CI 0.02-0.5); and gout 1 (0.09 %; 95 % CI 0.0-0.5). 53.2 % had not received medical treatment for their disease. The prevalence of MSK disorders in indigenous communities in the Mixtec and Chontal regions is very high. The most common rheumatic diseases found were back pain and osteoarthritis. A high percentage of participants had not received medical care.

  5. Maternal and Perinatal Outcomes by Mode of Delivery in Senegal and Mali: A Cross-Sectional Epidemiological Survey

    PubMed Central

    Briand, Valérie; Dumont, Alexandre; Abrahamowicz, Michal; Sow, Amadou; Traore, Mamadou; Rozenberg, Patrick; Watier, Laurence; Fournier, Pierre

    2012-01-01

    Objective In the context of rapid changes regarding practices related to delivery in Africa, we assessed maternal and perinatal adverse outcomes associated with the mode of delivery in 41 referral hospitals of Mali and Senegal. Study Design Cross-sectional survey nested in a randomised cluster trial (1/10/2007–1/10/2008). The associations between intended mode of delivery and (i) in-hospital maternal mortality, (ii) maternal morbidity (transfusion or hysterectomy), (iii) stillbirth or neonatal death before Day 1 and (iv) neonatal death between 24 hours after birth and hospital discharge were examined. We excluded women with immediate life threatening maternal or fetal complication to avoid indication bias. The analyses were performed using hierarchical logistic mixed models with random intercept and were adjusted for women's, newborn's and hospitals' characteristics. Results Among the 78,166 included women, 2.2% had a pre-labor cesarean section (CS) and 97.8% had a trial of labor. Among women with a trial of labor, 87.5% delivered vaginally and 12.5% had intrapartum CS. Pre-labor CS was associated with a marked reduction in the risk of stillbirth or neonatal death before Day 1 as compared with trial of labor (OR = 0.2 [0.16–0.36]), though we did not show that maternal mortality (OR = 0.3 [0.07–1.32]) and neonatal mortality after Day 1 (OR = 1.3 (0.66–2.72]) differed significantly between groups. Among women with trial of labor, intrapartum CS and operative vaginal delivery were associated with higher risks of maternal mortality and morbidity, and neonatal mortality after Day 1, as compared with spontaneous vaginal delivery. Conclusions In referral hospitals of Mali and Senegal, pre-labor CS is a safe procedure although intrapartum CS and operative vaginal delivery are associated with increased risks in mothers and infants. Further research is needed to determine what aspects of obstetric care contribute to a delay in the provision of intrapartum

  6. Epidemiology of polycystic ovary syndrome: a cross sectional study of university students at An-Najah national university-Palestine.

    PubMed

    Musmar, Samar; Afaneh, Asma; Mo'alla, Hafsa

    2013-05-20

    Polycystic Ovary Syndrome (PCOS) is the most common gynecological endocrinopathy in women of reproductive age. Despite its heavy burden on female reproduction and general health, there is no study regarding PCOS prevalence in Palestine. This study aims to establish prevalence of PCOS among female university students at An-Najah National University-Palestine and to explore its possible risk factors. A cross sectional study was conducted on 137 female students using convenience sampling method for age group (18-24) years. PCOS cases were identified according to the National Institute of health (NIH) criteria through clinical interview and assessment for participants at the University clinics. Menstrual irregularities regarding cycle and flow were identified and clinical hyperandrogenism was assessed as the self-reported degree of hirsutism using the modified Ferriman Gallwey (mF-G) scoring method of more than 8 score. Biochemical hyperandrogenism for girls with menstrual irregularities was assessed by measuring free testosterone level. Data were analyzed using SPSS version 17 applying descriptive methods; different risk factor relationships were estimated using bivariate analysis and multivariate logistic regression. The estimated prevalence of PCOS was 7.3%, acne was the only studied risk factor among others to be statistically significantly related to PCOS patients (OR=8.430, P-value=0.015). Clinical Hirsutism was found in 27% of participants, 70% of whom had idiopathic hirsutism. Prevalence of PCOS in Palestine seems to be relatively high but similar to other Mediterranean statistics. We recommend further studies using wider age group and larger sample for all parts of Palestine in order to generalize results.

  7. The epidemiology of dependency among urban-dwelling older people in the Dominican Republic; a cross-sectional survey

    PubMed Central

    Acosta, Daisy; Rottbeck, Ruth; Rodríguez, Guillermina; Ferri, Cleusa P; Prince, Martin J

    2008-01-01

    Background Demographic ageing, and the health transition will soon lead to large increases in the number of dependent older people in low and middle income countries. Despite its importance, this topic has not previously been studied. Methods A cross sectional catchment area one-phase survey of health conditions, dependency, care arrangements and caregiver strain among 2011 people aged 65 years and over in Santo Domingo, Dominican Republic Results 7.1% of participants required much care and a further 4.7% required at least some care. The prevalence of dependency increased sharply with increasing age. Dependent older people were less likely than others to have a pension and much less likely to have paid work, but no more likely to benefit from financial support from their family. Needing much care was strongly associated with comorbidity between cognitive, psychological and physical health problems. However, dementia made the strongest independent contribution. Among those needing care, those with dementia stood out as being more disabled, as needing more care (particularly support with core activities of daily living), and as being more likely to have paid caregivers. Dementia caregivers experienced more strain than caregivers of those with other health conditions, an effect mediated by behavioural and psychological symptoms. Conclusion Dependency among older people is nearly as prevalent in Dominican Republic as in developed western settings. Non-communicable diseases, particularly dementia are the main contributing factors. Attention needs to be directed towards the development of age-appropriate healthcare, a long-term care policy, and mechanisms for ensuring the social protection of older persons. PMID:18700967

  8. Epidemiology of Cervical Squamous Intraepithelial Lesions in HIV Infected Women in Kenya: a cross-Sectional Study.

    PubMed

    Memiah, Peter; Makokha, Violet; Mbuthia, Wangeci; Kiiru, Grace Wanjiku; Agbor, Solomon; Odhiambo, Francesca; Ojoo, Sylvia; Mbizo, Justice; Muhula, Samuel; Mahasi, Gabriel; Biadgilign, Sibhatu

    2015-03-01

    Cervical cancer is the second most common cancer among women worldwide. Infection with the human immunodeficiency virus (HIV) and its related immunosuppression are associated with an increased risk of prevalent, incident, and persistent squamous intraepithelial lesions (SILs) of the cervix. The objective of the study was to describe the prevalence and predictors of high-risk HPV and cervical cancer to support the need for strengthening cervical cancer screening programs for HIV infected women in Kenya. A cross sectional study was conducted in a hospital in Central Kenya, Kiambu district. The study population constituted of HIV positive women attending the ART treatment clinic. A total of 715 HIV positive women initiated on Antiretroviral Therapy (ART) were enrolled in this study. About 359 (52.1%) were less than 40 years of age and 644 (90.3%) of the patients were widowed. About 642 (92.6%) of the HIV infected women were in follow-up period of ≥ 1 year. The outcome/prognosis of the patients undergoing ICC was 3 cured, 5 good and 4 poor respectively. In a multivariable ordinal logistic regression analysis showed that for a one-unit decrease of CD4, we expect 1.23 log odds of increasing the severity of cervical cancer (B = 1.23, P < 0.0 15), given that all of the other variables in the model are held constant. In conclusion screening of all HIV infected women, who are under HIV care and treatment, enrolling patients on HAART with higher CD4 counts is recommended to see the net effect of HAART response.

  9. Perceived stress and musculoskeletal pain are prevalent and significantly associated in adolescents: an epidemiological cross-sectional study.

    PubMed

    Østerås, Berit; Sigmundsson, Hermundur; Haga, Monika

    2015-10-23

    Long-term musculoskeletal pain and negative stress are health risks with adverse long-term health effects, and these health risks seem to increase among young people. The mechanisms behind this are unclear. There is a need for a better understanding of perceived stress and musculoskeletal pain among adolescents, in order to improve health promotion and treatment approaches in this group. Objectives were to evaluate the current prevalence of perceived stress and musculoskeletal pain in 15 and 16 year olds, to explore stress-pain associations and the probability that perceived stress (PSQ) was related to the reporting of pain and variations in pain, and to investigate possible differences in stress between different types of musculoskeletal pain in the adolescents. A cross-sectional study was conducted. Elementary schools participated. The outcomes were stress (Perceived stress questionnaire; PSQ) and musculoskeletal pain (pain/no pain, pain sites, pain duration and pain intensity (Visual analogue scale; VAS). Fifty-one point two percent (N = 422) reported pain, of which 70.8 % reported long-term pain. Some more girls (57.9 %) reported pain. 22.0 % of the study population reported moderate to severe stress (PSQ ≥ 0.45), of which 79.6 % were bothered by pain (Pearson Chi-square 38.47, p ≤ .001). All stress and pain variables were significantly associated (p < .01). The strongest association appeared between pain intensity (VAS) and stress (PSQ) (r = 0.40). Perceived stress (PSQ) was associated with the reporting of pain among the adolescents (Odds Ratio [OR] 1.68) and could explain some of the variation in pain intensity (VAS; β = 0.15, p < .001) and number of pain sites (β = 0.14, p < .01), according to the regression analyses. There were no mean differences in stress (PSQ) between different types of musculoskeletal pain. There was high prevalence of musculoskeletal pain, long-term pain and moderate to severe stress (PSQ

  10. Association between randomised trial evidence and global burden of disease: cross sectional study (Epidemiological Study of Randomized Trials—ESORT)

    PubMed Central

    Odutayo, Ayodele; Hsiao, Allan J; Shakir, Mubeen; Hopewell, Sally; Rahimi, Kazem; Altman, Douglas G

    2015-01-01

    Objectives To determine whether an association exists between the number of published randomised controlled trials and the global burden of disease, whether certain diseases are under-investigated relative to their burden, and whether the relation between the output of randomised trials and global burden of disease can be explained by the relative disease burden in high and low income regions. Design Cross sectional investigation. Study sample All primary reports of randomised trials published in December 2012 and indexed in PubMed by 17 November 2013. Main outcome measures Number of trials conducted and number of participants randomised for each of 239 different diseases or injuries; variation in each outcome explainable by total disability adjusted life years (a measure of the overall burden of each disease) and the ratio of disability adjusted life years in low income to high income regions (a measure of whether a disease is more likely to affect people living in high income regions) quantified using multivariable regression. Results 4190 abstracts were reviewed and 1351 primary randomised trials identified, of which 1097 could be classified using the global burden of disease taxonomy. Total disability adjusted life years was poorly associated with number of randomised trials and number of participants randomised in univariable analysis (Spearman’s r=0.35 and 0.33, respectively), although it was a significant predictor in the univariable and multivariable models (P<0.001). Diseases for which the burden was predominantly located in low income regions had sevenfold fewer trials per million disability adjusted life years than diseases predominantly located in high income regions. However, only 26% of the variation in number of trials among diseases could be explained by total disability adjusted life years and the ratio of disability adjusted life years in low income regions to high income regions. Many high income type diseases (for example, neck pain

  11. Epidemiological and clinical profile of paediatric malaria: a cross sectional study performed on febrile children in five epidemiological strata of malaria in Cameroon.

    PubMed

    Kwenti, Tebit Emmanuel; Kwenti, Tayong Dizzle Bita; Latz, Andreas; Njunda, Longdoh Anna; Nkuo-Akenji, Theresa

    2017-07-17

    In the wake of a decline in global malaria, it is imperative to describe the epidemiology of malaria in a country to inform control policies. The purpose of this study was to describe the epidemiological and clinical profile of paediatric malaria in five epidemiological strata of malaria in Cameroon including: the Sudano-sahelian (SS) strata, the High inland plateau (HIP) strata, the South Cameroonian Equatorial forest (SCEF) strata, the High western plateau (HWP) strata, and the Coastal (C) strata. This study involved 1609 febrile children (≤15 years) recruited using reference hospitals in the five epidemiological strata. Baseline characteristics were determined; blood glucose level was measured by a glucometer, malaria parasitaemia was assessed by Giemsa microscopy, and complete blood count was performed using an automated hematology analyser. Severe malaria was assessed and categorized based on WHO criteria. An overall prevalence of 15.0% (95% CI: 13.3-16.9) for malaria was observed in this study. Malaria prevalence was significantly higher in children between 60 and 119 months (p < 0.001) and in Limbe (C strata) (p < 0.001). The overall rate of severe malaria (SM) attack in this study was 29.3%; SM was significantly higher in children below 60 months (p < 0.046). Although not significant, the rate of SM was highest in Maroua (SS strata) and lowest in Limbe in the C strata. The main clinical phenotypes of SM were hyperparasitaemia, severe malaria anaemia and impaired consciousness. The majority (73.2%) of SM cases were in group 1 of the WHO classification of severe malaria (i.e. the most severe form). The malaria case-fatality rate was 5.8%; this was higher in Ngaoundere (HIP strata) (p = 0.034). In this study, malaria prevalence decreased steadily northward, from the C strata in the South to the SS strata in the North of Cameroon, meanwhile the mortality rate associated with malaria increased in the same direction. On the contrary, the rate of

  12. A cross-sectional epidemiological survey of bovine trypanosomosis and its vectors in the Savelugu and West Mamprusi districts of northern Ghana.

    PubMed

    Mahama, C I; Desquesnes, M; Dia, M L; Losson, B; De Deken, R; Geerts, S

    2004-06-10

    The epidemiology of bovine trypanosomosis was investigated in two districts (Savelugu and West Mamprusi) of Northern Ghana with different land use and environmental characteristics. The land use intensity and environmental change was suspected to be higher in the Savelugu District. A cross-sectional entomological survey conducted along the White Volta river and its tributaries confirmed the presence of only Glossina palpalis gambiensis and G. tachinoides. The challenge index as measured by the product of tsetse density and tsetse infection rate was much higher in the West Mamprusi (19.6) than in the Savelugu district (4.7). A total of 1013 cattle (508 in Savelugu and 505 in West Mamprusi) were bled from a random selection of 16 villages in the Savelugu District and 13 villages in the West Mamprusi District. Blood samples were examined for trypanosomes by the buffy coat technique (BCT). Blood samples that were positive in the BCT or negative in the BCT but with packed cell volume (PCV) values below 21 were further tested with a polymerase chain reaction for trypanosomal DNA. Plasma samples of all cattle were serologically tested with an indirect ELISA for trypanosomal antibodies. The parasitological and serological prevalence of bovine trypanosomoses was significantly higher in West Mamprusi (16 and 53%, respectively) than in Savelugu District (8 and 24%, respectively). An evaluation of animal health at the village herd level, using PCV as an index of anaemia, provided various epidemiological scenarios prevalent in the entire study area.

  13. Factors associated with postpartum hemorrhage maternal death in referral hospitals in Senegal and Mali: a cross-sectional epidemiological survey.

    PubMed

    Tort, Julie; Rozenberg, Patrick; Traoré, Mamadou; Fournier, Pierre; Dumont, Alexandre

    2015-09-30

    Postpartum hemorrhage (PPH) is the leading cause of maternal mortality in Sub-Saharan-Africa (SSA). Although clinical guidelines treating PPH are available, their implementation remains a great challenge in resource poor settings. A better understanding of the factors associated with PPH maternal mortality is critical for preventing risk of hospital-based maternal death. The purpose of this study was thus to assess which factors contribute to maternal death occurring during PPH. The factors were as follows: women's characteristics, aspects of pregnancy and delivery; components of PPH management; and organizational characteristics of the referral hospitals in Senegal and Mali. A cross-sectional survey nested in a cluster randomized trial (QUARITE trial) was carried out in 46 referral hospitals during the pre-intervention period from October 2007 to September 2008 in Senegal and Mali. Individual and hospital characteristics data were collected through standardized questionnaires. A multivariable logistic mixed model was used to identify the factors that were significantly associated with PPH maternal death. Among the 3,278 women who experienced PPH, 178 (5.4%) of them died before hospital discharge. The factors that were significantly associated with PPH maternal mortality were: age over 35 years (adjusted OR = 2.16 [1.26-3.72]), living in Mali (adjusted OR = 1.84 [1.13-3.00]), residing outside the region location of the hospital (adjusted OR = 2.43 [1.29-4.56]), pre-existing chronic disease before pregnancy (adjusted OR = 7.54 [2.54-22.44]), prepartum severe anemia (adjusted OR = 6.65 [3.77-11.74]), forceps or vacuum delivery (adjusted OR = 2.63 [1.19-5.81]), birth weight greater than 4000 grs (adjusted OR = 2.54 [1.26-5.10]), transfusion (adjusted OR = 2.17 [1.53-3.09]), transfer to another hospital (adjusted OR = 13.35 [6.20-28.76]). There was a smaller risk of PPH maternal death in hospitals with gynecologist

  14. Intelligence and temperament as protective factors for mental health. A cross-sectional and prospective epidemiological study.

    PubMed

    Cederblad, M; Dahlin, L; Hagnell, O; Hansson, K

    1995-01-01

    The Sjöbring system of personality dimensions measuring intellectual capacity, activity, impulsivity and sociability was used to study possible "salutogenic" (i.e. causes of health) effects. The study comprised 590 subjects investigated in 1947, 1957, 1972 and 1988-1989 in the Lundby project, an epidemiological study in Sweden. Psychiatric diagnoses were made in 1947, 1957 and 1972. Mental health was estimated in 1988-1989 using the concept "love well, work well, play well and expect well". The Sjöbring dimensions were clinically assessed in 1972. Both in the concurrent study in 1972 and in the prospective study in 1988-1989 "super capacity" (high intellectual function), "super validity" (high activity level) and "super solidity" (low impulsivity) were statistically associated with lower frequencies of certain psychiatric diagnoses and a higher frequency of positive mental health. These variables are proposed to increase coping capacity, and therefore increase stress resilience.

  15. Epidemiology of Clostridium difficile infection in two tertiary-care hospitals in Perth, Western Australia: a cross-sectional study.

    PubMed

    Foster, N F; Collins, D A; Ditchburn, S L; Duncan, C N; van Schalkwyk, J W; Golledge, C L; Keed, A B R; Riley, T V

    2014-05-01

    The epidemiology of Clostridium difficile infection (CDI) has changed over time and between countries. It is therefore essential to monitor the characteristics of patients at risk of infection and the circulating strains to recognize local and global trends, and improve patient management. From December 2011 to May 2012 we conducted a prospective, observational epidemiological study of patients with laboratory-confirmed CDI at two tertiary teaching hospitals in Perth, Western Australia to determine CDI incidence and risk factors in an Australian setting. The incidence of CDI varied from 5.2 to 8.1 cases/10 000 occupied bed days (OBDs) at one hospital and from 3.9 to 16.3/10 000 OBDs at the second hospital. In total, 80 patients with laboratory-confirmed CDI met eligibility criteria and consented to be in the study. More than half (53.8%) had hospital-onset disease, 28.8% had community-onset and healthcare facility-associated disease and 7.5% were community-associated infections according to the definitions used. Severe CDI was observed in 40.0% of these cases but the 30-day mortality rate for all cases was only 2.5%. Besides a shorter length of stay among cases of community-onset CDI, no characteristics were identified that were significantly associated with community-onset or severe CDI. From 70 isolates, 34 different ribotypes were identified. The predominant ribotypes were 014 (24.3%), 020 (5.7%), 056 (5.7%) and 070 (5.7%). Whereas this study suggests that the characteristics of CDI cases in Australia are not markedly different from those in other developed countries, the increase in CDI rate observed emphasizes the importance of surveillance.

  16. Descriptive epidemiology and high risk behavior of male prescription opioid abusers: Cross-sectional study from Sikkim, North East India.

    PubMed

    Datta, D; Pandey, S; Dutta, S; Verma, Y; Chakrabarti, Amit

    2015-01-01

    Sikkim is emerging as an important area for prescription opioid abuse with frequent news of seizures and arrests due to possession of prescription opioids. However, till date there is a little information on descriptive epidemiology and high risk behavior of prescription opioid abusers from Sikkim. The aim was to describe demographic (age, sex, religion, marital status, community, occupation, etc.); socioeconomic (income, education, family information etc.); and high risk behavior (e.g., injection sharing, visit to commercial sex workers [CSWs], homosexuality etc.) among treatment-seeking prescription opioid abusers in Sikkim. Epidemiological data were collected by administering predevised questionnaires from n = 223 prescription opioid abusers (main problem prescription opioids) reporting for treatment at five different drug abuse treatment centers across Sikkim. The mean age of prescription opioid abusers in Sikkim was 27 years; all were male, of Nepalese ethnicity and single/never married, school dropout and/or illiterate, earning < Rs. 10,000/month with most spending almost Rs. 5000 a month on prescription opioids. Most (57.4%) prescription opioid abusers belonged to the urban community. Commonly abused prescription opioids were dextropropoxyphene and codeine. Injection sharing was more in urban areas whereas syringe exchange was observed equally among rural and urban prescription opioid abusers. Among urban injectors visits to CSWs, and multiple sex partners were also common in spite of knowledge about AIDS. Limited condom use was observed among rural respondents. Incidences of arrests, public intoxication, and violence under the influence of prescription opioids were also reported. Both the rural and urban areas of Sikkim show increasing rates of prescription opioid abuse among males. It is more prevalent among school dropouts and unemployed youth. Trends of injection drug use, unsafe injection, high risk behavior have also been observed.

  17. Sporotrichoid leishmaniasis: a cross-sectional clinical, epidemiological and laboratory study in Rio de Janeiro State, Brazil.

    PubMed

    Carvalho, Livia Martins Veloso de; Pimentel, Maria Inês Fernandes; Conceição-Silva, Fátima; Vasconcellos, Érica de Camargo Ferreira E; Valete-Rosalino, Cláudia Maria; Lyra, Marcelo Rosandiski; Salgueiro, Mariza de Matos; Saheki, Maurício Naoto; Madeira, Maria de Fátima; Mouta-Confort, Eliame; Antonio, Liliane de Fátima; Silva, Aline Fagundes da; Quintella, Leonardo Pereira; Bedoya-Pacheco, Sandro Javier; Schubach, Armando de Oliveira

    2017-06-01

    Atypical presentations of cutaneous leishmaniasis include sporotrichoid leishmaniasis (SL), which is clinically described as a primary ulcer combined with lymphangitis and nodules and/or ulcerated lesions along its pathway. To assess the differences between patients with sporotrichoid leishmaniasis and typical cutaneous leishmaniasis (CL). From January 2004 to December 2010, 23 cases of SL (4.7%) were detected among 494 CL patients diagnosed at a reference center for the disease in Rio de Janeiro State, Brazil. These 23 cases were compared with the remaining 471 patients presenting CL. SL predominated in female patients (60.9%, p = 0.024), with older age (p = 0.032) and with lesions in upper limbs (52.2%, p = 0.028). CL affected more men (64.5%), at younger age, and with a higher number of lesions exclusively in lower limbs (34.8%). Differences in clinical and epidemiological presentation were found between SL patients as compared to CL ones, in a region with a known predominance of Leishmania (Viannia) braziliensis. The results are similar to the features of most of the sporotrichosis patients as described in literature, making the differential diagnosis between ATL and sporotrichosis more important in overlapping areas for both diseases, like in Rio de Janeiro State.

  18. Sporotrichoid leishmaniasis: a cross-sectional clinical, epidemiological and laboratory study in Rio de Janeiro State, Brazil

    PubMed Central

    de Carvalho, Livia Martins Veloso; Pimentel, Maria Inês Fernandes; Conceição-Silva, Fátima; Vasconcellos, Érica de Camargo Ferreira e; Valete-Rosalino, Cláudia Maria; Lyra, Marcelo Rosandiski; Salgueiro, Mariza de Matos; Saheki, Maurício Naoto; Madeira, Maria de Fátima; Mouta-Confort, Eliame; Antonio, Liliane de Fátima; da Silva, Aline Fagundes; Quintella, Leonardo Pereira; Bedoya-Pacheco, Sandro Javier; Schubach, Armando de Oliveira

    2017-01-01

    ABSTRACT Background Atypical presentations of cutaneous leishmaniasis include sporotrichoid leishmaniasis (SL), which is clinically described as a primary ulcer combined with lymphangitis and nodules and/or ulcerated lesions along its pathway. Aims To assess the differences between patients with sporotrichoid leishmaniasis and typical cutaneous leishmaniasis (CL). Methods From January 2004 to December 2010, 23 cases of SL (4.7%) were detected among 494 CL patients diagnosed at a reference center for the disease in Rio de Janeiro State, Brazil. These 23 cases were compared with the remaining 471 patients presenting CL. Results SL predominated in female patients (60.9%, p = 0.024), with older age (p = 0.032) and with lesions in upper limbs (52.2%, p = 0.028). CL affected more men (64.5%), at younger age, and with a higher number of lesions exclusively in lower limbs (34.8%). Conclusions Differences in clinical and epidemiological presentation were found between SL patients as compared to CL ones, in a region with a known predominance of Leishmania (Viannia) braziliensis. The results are similar to the features of most of the sporotrichosis patients as described in literature, making the differential diagnosis between ATL and sporotrichosis more important in overlapping areas for both diseases, like in Rio de Janeiro State. PMID:28591261

  19. Epidemiology of Mycoplasma acquisition in male HIV-1 infected patients: a multistage cross-sectional survey in Jiangsu, China.

    PubMed

    Chen, L-S; Wu, J-R; Wang, B; Yang, T; Yuan, R; Zhao, Y-Y; Xu, J-S; Guo, H-X; Huan, X-P

    2015-11-01

    Mycoplasma infections are most frequently associated with disease in the urogenital or respiratory tracts and, in most cases, mycoplasmas infect the host persistently. In HIV-infected individuals the prevalence and role of genital mycoplasmas has not been well studied. To investigate the six species of Mycoplasma and the risk factors for infection in Jiangsu province, first-void urine and venous blood samples were collected and epidemiological questionnaires were administered after informed consent. A total of 1541 HIV/AIDS patients were recruited in this study. The overall infection rates of six Mycoplasma species were: Ureaplasma urealyticum (26·7%), Mycoplasma hominis (25·3%), M. fermentans (5·1%), M. genitalium (20·1%), M. penetrans (1·6%) and M. pirum (15·4%). The Mycoplasma infection rate in the unmarried group was lower than that of the married, divorced and widowed groups [adjusted odds ratio (aOR) 1·432, 95% confidence interval (CI) 1·077-1·904, P < 0·05]. The patients who refused highly active antiretroviral therapy (HAART) had a much higher risk of Mucoplasma infection (aOR 1·357, 95% CI 1·097-1·679, P < 0·05). Otherwise, a high CD4+ T cell count was a protective factor against Mycoplasma infection (aOR 0·576, 95% CI 0·460-0·719, P < 0·05). Further research will be required to confirm a causal relationship and to identify risk factors for Mycoplasma infection in HIV/AIDS populations.

  20. The epidemiologic characteristics, temporal trends, predictors of death, and discharge disposition in patients with a diagnosis of sepsis: A cross-sectional retrospective cohort study.

    PubMed

    Elfeky, Sarah; Golabi, Pegah; Otgonsuren, Munkhzul; Djurkovic, Svetolik; Schmidt, Mary E; Younossi, Zobair M

    2017-06-01

    To assess recent epidemiologic characteristics, temporal trends, and predictors of death and discharge disposition in patients with sepsis. This is a cross-sectional retrospective cohort study using the US National Inpatient Sample (NIS) data from 2009 to 2012. The study population included adults (18years and older) with sepsis-related International Classification of Diseases, Ninth Revision, Clinical Modification codes at the time of discharge. Factors associated with in-hospital mortality and patient discharge disposition were derived from multivariate analyses using multinomial logistic models by SAS PROC LOGISTIC with GLOGIT link. Of 1 303 640 patients admitted, 15% died, 30% were discharged to home without home care, 34% were transferred to a skilled outpatient facility, and 4% were transferred to another short-term hospital. In-hospital mortality decreased from 16.5% to 13.8% (P<.001) across time. Length of stay also decreased from 6.7 to 5.9days (P<.001). Reductions in mortality and length of stay were seen despite an increase in the number of comorbidities (P<.001). Multivariate analysis revealed that the strongest predictors of in-hospital mortality were respiratory, cardiovascular, and hepatic failures, and neurologic events. The predictors of transfer to an outpatient facility were a major operative procedure, neurologic event, respiratory failure, and weight loss. Weight loss was also an independent predictor of in-hospital mortality. Certain comorbidities and organ failures were associated with death and discharge to a skilled outpatient facility. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Quantum radar cross sections

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2010-06-01

    The radar cross section σC is an objective measure of the "radar visibility" of an object. As such, σC is an important concept for the correct characterization of the operational performance of radar systems. Furthermore, σC is equally essential for the design and development of stealth weapon systems and platforms. Recent years have seen the theoretical development of quantum radars, that is, radars that operate with a small number of photons. In this regime, the radar-target interaction is described through photon-atom scattering processes governed by the laws of quantum electrodynamics. As such, it is theoretically inconsistent to use the same σC to characterize the performance of a quantum radar. In this paper we define a quantum radar cross section σQ based on quantum electrodynamics and interferometric considerations. We discuss the theoretical challenges of defining σQ, as well as computer simulations of σC and σQ for simple targets.

  2. New Arsenic Cross Section Calculations

    SciTech Connect

    Kawano, Toshihiko

    2015-03-04

    This report presents calculations for the new arsenic cross section. Cross sections for 73,74,75 As above the resonance range were calculated with a newly developed Hauser-Feshbach code, CoH3.

  3. Current status of the clinical epidemiology of myocardial infarction in men and women: a national cross-sectional study in iran.

    PubMed

    Ahmadi, Ali; Soori, Hamid; Sajjadi, Homeira; Nasri, Hamid; Mehrabi, Yadollah; Etemad, Koorosh

    2015-01-01

    Cardiovascular disease is the main reason for mortality in men and women. Clinical epidemiology of myocardial infarction (MI) in men and women has not been yet studied in Iran, one of the largest Middle East countries in South-Western Asia. This study was conducted to determine the clinical epidemiology of MI in men and women in Iran. This hospital-based, cross-sectional study used the data of 20,750 MI patients in Iran in 2012 (the codes I22, I21, I24, and I25.2). Univariate comparisons used Chi-square test for categorical variables and t-test for continuous variables. P < 0.05 was considered as significant. Totally, 20,750 MI patients (15,033 men and 5,717 women) with age range of 13-106 (mean; 61.2 ± 13.4) years were enrolled. Only 9 (0.04%) patients (8 men and 1 woman) were ≤18 years (mean age: 14.8 ± 1.9), out of whom only two men were diabetic. 22.2% (18% men and 33.4% women) of the patients had diabetes, 26.2% (28.5% men and 20.1% women) were smoker and 35.5% (28.6% men and 53.7% women) had hypertension. ST-segment elevation MI incidence was 2.8 times higher in men than women. Left bundle branch block was significantly more prevalent in men than women. Men used percutaneous coronary intervention more frequently than women did. No difference in coronary artery bypass graft was noted between men and women. Mortality incidence was approximately twice higher in men than women. The prevalence of chest pain was higher in women than men. The MI incidence pattern, mortality from MI, and risk factors prevalence are significantly different between men and women in Iran. More emphasis on these issues in training people and healthcare professionals seems to contribute partially to patients' timely referring to health care centers and preventing MI-associated mortalities.

  4. Current Status of the Clinical Epidemiology of Myocardial Infarction in Men and Women: A National Cross-Sectional Study in Iran

    PubMed Central

    Ahmadi, Ali; Soori, Hamid; Sajjadi, Homeira; Nasri, Hamid; Mehrabi, Yadollah; Etemad, Koorosh

    2015-01-01

    Background: Cardiovascular disease is the main reason for mortality in men and women. Clinical epidemiology of myocardial infarction (MI) in men and women has not been yet studied in Iran, one of the largest Middle East countries in South-Western Asia. This study was conducted to determine the clinical epidemiology of MI in men and women in Iran. Methods: This hospital-based, cross-sectional study used the data of 20,750 MI patients in Iran in 2012 (the codes I22, I21, I24, and I25.2). Univariate comparisons used Chi-square test for categorical variables and t-test for continuous variables. P < 0.05 was considered as significant. Results: Totally, 20,750 MI patients (15,033 men and 5,717 women) with age range of 13–106 (mean; 61.2 ± 13.4) years were enrolled. Only 9 (0.04%) patients (8 men and 1 woman) were ≤18 years (mean age: 14.8 ± 1.9), out of whom only two men were diabetic. 22.2% (18% men and 33.4% women) of the patients had diabetes, 26.2% (28.5% men and 20.1% women) were smoker and 35.5% (28.6% men and 53.7% women) had hypertension. ST-segment elevation MI incidence was 2.8 times higher in men than women. Left bundle branch block was significantly more prevalent in men than women. Men used percutaneous coronary intervention more frequently than women did. No difference in coronary artery bypass graft was noted between men and women. Mortality incidence was approximately twice higher in men than women. The prevalence of chest pain was higher in women than men. Conclusions: The MI incidence pattern, mortality from MI, and risk factors prevalence are significantly different between men and women in Iran. More emphasis on these issues in training people and healthcare professionals seems to contribute partially to patients’ timely referring to health care centers and preventing MI-associated mortalities. PMID:25789146

  5. Difference between interaction cross sections and reaction cross sections

    SciTech Connect

    Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

    2008-12-15

    We study the validity of the substitution of interaction cross sections for total reaction cross sections for a nucleus incident on a target nucleus at relativistic energies. We show that, for incident stable nuclei, the predicted difference between interaction and total reaction cross sections is large enough to probe the nuclear structure, particularly in a mass region of less than around 40. For analyses of the difference, we construct ''pseudo data'' for the reaction cross sections because empirical data are very limited at high energies. The construction of the pseudo data is based on our assumption that empirically unknown total reaction cross sections are precisely predicted by the phenomenological black-sphere model of nuclei that we developed recently. The comparison with the empirical interaction cross sections suggests a significant difference between the reaction and interaction cross sections for stable projectiles on a carbon target, which is of the order of 0-100 mb.

  6. General epidemiological parameters of viral hepatitis A, B, C, and E in six regions of China: a cross-sectional study in 2007.

    PubMed

    Lu, Jian; Zhou, Yongdong; Lin, Xiaojing; Jiang, Yongzhen; Tian, Ruiguang; Zhang, Yonghui; Wu, Jia; Zhang, Fengwei; Zhang, Yong; Wang, Yue; Bi, Shengli

    2009-12-24

    Viral hepatitis is a serious health burden worldwide. To date, few reports have addressed the prevalence of hepatitis A, B, C, and E in China. Therefore, the general epidemiological parameters of viral hepatitis remain unknown. In this cross-sectional study, we performed a serological prevalence analysis of viral hepatitis A, B, C, and E in 8,762 randomly selected Chinese subjects, which represented six areas of China. The overall prevalence of anti-Hepatitis C virus antibody (anti-HCV) was 0.58%, which was much lower than was estimated by WHO. The prevalences of Hepatitis B virus surface antigen (HBsAg), anti-Hepatitis B virus surface protein antibody (HBsAb), and anti-Hepatitis B virus core protein antibody (HBcAb) were 5.84%, 41.31%, and 35.92%, respectively, whereas in the group of subjects less than 5 years old, these prevalences were 1.16%, 46.77%, and 8.69% respectively, which suggests that the Hepatitis B virus (HBV)-carrier population is decreasing, and the nationwide HBV vaccine program has contributed to the lowered HBV prevalence in the younger generation in China. Meanwhile, a large deficit remains in coverage provided by the national HBV immune program. In addition, our data suggested the possibility that HBsAb may not last long enough to protect people from HBV infection throughout life. The overall prevalence of anti-Hepatitis A virus antibody (anti-HAV) and anti-Hepatitis E virus antibody (anti-HEV) were as high as 72.87% and 17.66%, respectively. The indices increased with age, which suggests that a large proportion of Chinese adults are protected by latent infection. Furthermore, the pattern of HEV infection was significantly different among ethnic groups in China. Our study provided much important information concerning hepatitis A, B, C, and E prevalence in China and will contribute to worldwide oversight of viral hepatitis.

  7. Epidemiology of multimorbidity in China and implications for the healthcare system: cross-sectional survey among 162,464 community household residents in southern China.

    PubMed

    Wang, Harry H X; Wang, Jia Ji; Wong, Samuel Y S; Wong, Martin C S; Li, Fang Jian; Wang, Pei Xi; Zhou, Zhi Heng; Zhu, Chun Yan; Griffiths, Sian M; Mercer, Stewart W

    2014-10-23

    China, like other countries, is facing a growing burden of chronic disease but the prevalence of multimorbidity and implications for the healthcare system have been little researched. We examined the epidemiology of multimorbidity in southern China in a large representative sample. The effects of multimorbidity and other factors on usual source of healthcare were also examined. We conducted a large cross-sectional survey among approximately 5% (N = 162,464) of the resident population in three prefectures in Guangdong province, southern China in 2011. A multistage, stratified random sampling was adopted. The study population had many similar characteristics to the national census population. Interviewer-administered questionnaires were used to collect self-report data on demographics, socio-economics, lifestyles, healthcare use, and health characteristics from paper-based medical reports. More than one in ten of the total study population (11.1%, 95% confidence interval (CI) 10.6 to 11.6) had two or more chronic conditions from a selection of 40 morbidities. The prevalence of multimorbidity increased with age (adjusted odds ratio (aOR) = 1.36, 95% CI 1.35 to 1.38 per five years). Female gender (aOR = 1.70, 95% CI 1.64 to 1.76), low education (aOR = 1.26, 95% CI 1.23 to 1.29), lack of medical insurance (aOR = 1.79, 95% CI 1.71 to 1.89), and unhealthy lifestyle behaviours were independent predictors of multimorbidity. Multimorbidity was associated with the regular use of secondary outpatient care in preference to primary care. Multimorbidity is now common in China. The reported preferential use of secondary care over primary care by patients with multimorbidity has many major implications. There is an urgent need to further develop a strong and equitable primary care system.

  8. Epidemiology of group A streptococcal pharyngitis & impetigo: a cross-sectional & follow up study in a rural community of northern India.

    PubMed

    Kumar, R; Vohra, H; Chakraborty, A; Sharma, Y P; Bandhopadhya, S; Dhanda, V; Sagar, V; Sharma, M; Shah, B; Ganguly, N K

    2009-12-01

    Group A streptococcus (GAS) causes a wide array of human diseases. Epidemiological picture of streptococcal infection in India is not complete. Hence, disease burden due to GAS in 5-15 yr old school children in northern India was studied and emm typing of GAS isolates was carried out to help in designing prevention strategies. A cross-sectional survey was carried out among 4249 school children (5-15 yr) from Raipur Rani Block of Panchkula district in Haryana during 2000-2002; 334 children were followed up fortnightly for one year. Standard clinical and microbiological procedures were used for collection of swabs from throat and skin and confirmation of GAS and its emm types. Of the 4249 children studied, 658 (15.5%) had pharyngitis; 579 of them could be swabbed, of which 2.8 per cent had GAS. From 3591 children without pharyngitis, 3385 who could be swabbed, GAS was found in 1.3 per cent of them. Impetigo was rare (0.7%), but 7.1 per cent (2/28) children had GAS. In the followup study, 17.4 per cent (776/4447 child-contacts) had pharyngitis, 761 could be swabbed and 2.4 per cent had GAS; among those without pharyngitis, 2016 swabs could be taken and GAS was found in 1.3 per cent; whereas only 2.6 per cent (2/75) of skin sores had GAS. Three children had GAS pharyngitis twice during follow up. Fourteen different GAS emm types were found. emm 71, 77 and 81 constituted 69 per cent of the pharyngeal isolates. GAS pharyngitis and impetigo were more common in winters and summers respectively. In north India, pharyngitis was more common than impetigo. Most prevalent emm types of GAS in this region differ from those included in M protein-based vaccines.

  9. Prevalence of diabetic retinopathy among 13473 patients with diabetes mellitus in China: a cross-sectional epidemiological survey in six provinces

    PubMed Central

    Song, Yifan; Tao, Liyuan; Qiu, Weiqiang; Lv, Huibin; Jiang, Xiaodan; Zhang, Mingzhou; Li, Xuemin

    2017-01-01

    Objective To describe the prevalence and severity of diabetic retinopathy (DR) and sight-threatening DR (STDR) among Chinese adults with diabetes. Design, setting and participants A cross-sectional epidemiological survey across Mainland China (N=13 473). Participants were diagnosed with diabetes mellitus by physicians and transferred to our screening clinics (1/3 from hospital patients, 1/3 from city residents, the other 1/3 from rural residents). 2 fundus photographs were taken of each eye with a colourful, non-mydriatic and non-stereoscopic camera and were graded according to the UK guidelines. Main outcomes and measures The prevalence and severity of DR and STDR. Results Of the 13 473 participants with diabetes participating in the study, 4591 had DR and 1769 had STDR, for an overall prevalence of 34.08% (95% CI 33.28% to 34.88%) and 13.13% (95% CI 12.56% to 13.70%), respectively. Among these, gradable photographs were available for 12 780 participants (94.86%). Participants who were aged >65 years were less likely to suffer from DR or STDR (p<0.001; age distribution). No gender-related differences were present (p>0.05). Participants with STDR suffered from more severe visual impairment compared with those without STDR (p<0.001). The prevalence of DR and STDR in the northern region was higher than in the southern region (p<0.001). The prevalence of DR was closely related to duration of disease (OR 2.63; 95% CI 2.42 to 2.86; p<0.001) and diabetes onset age (OR 0.38; 95% CI 0.35 to 0.41; p<0.001). Conclusions The prevalence of DR and STDR in Mainland China appeared a little high, and varied according to area. Non-proliferative DR was more common, but STDR needed prompt treatment, especially in economically less developed areas. This study highlights the necessity for DR screening and treatment in Mainland China. PMID:28069622

  10. A national cross-sectional study among drug-users in France: epidemiology of HCV and highlight on practical and statistical aspects of the design

    PubMed Central

    2009-01-01

    Background Epidemiology of HCV infection among drug users (DUs) has been widely studied. Prevalence and sociobehavioural data among DUs are therefore available in most countries but no study has taken into account in the sampling weights one important aspect of the way of life of DUs, namely that they can use one or more specialized services during the study period. In 2004–2005, we conducted a national seroepidemiologic survey of DUs, based on a random sampling design using the Generalised Weight Share Method (GWSM) and on blood testing. Methods A cross-sectional multicenter survey was done among DUs having injected or snorted drugs at least once in their life. We conducted a two stage random survey of DUs selected to represent the diversity of drug use. The fact that DUs can use more than one structure during the study period has an impact on their inclusion probabilities. To calculate a correct sampling weight, we used the GWSM. A sociobehavioral questionnaire was administered by interviewers. Selected DUs were asked to self-collect a fingerprick blood sample on blotting paper. Results Of all DUs selected, 1462 (75%) accepted to participate. HCV seroprevalence was 59.8% [95% CI: 50.7–68.3]. Of DUs under 30 years, 28% were HCV seropositive. Of HCV-infected DUs, 27% were unaware of their status. In the month prior to interview, 13% of DUs shared a syringe, 38% other injection parapharnelia and 81% shared a crack pipe. In multivariate analysis, factors independently associated with HCV seropositivity were age over 30, HIV seropositivity, having ever injected drugs, opiate substitution treatment (OST), crack use, and precarious housing. Conclusion This is the first time that blood testing combined to GWSM is applied to a DUs population, which improve the estimate of HCV prevalence. HCV seroprevalence is high, indeed by the youngest DUs. And a large proportion of DUs are not aware of their status. Our multivariate analysis identifies risk factors such as crack

  11. Epidemiology and Risk Factors of Cervical Spine Injury during Heating Season in the Patients with Cervical Trauma: A Cross-Sectional Study

    PubMed Central

    Yang, Sidong; Ding, Wenyuan; Yang, Dalong; Gu, Tixin; Zhang, Feng; Zhang, Di; Sun, Yapeng; Ma, Lei; Song, Yanli

    2013-01-01

    Purpose The purpose of this study was to describe the epidemiology of cervical spine injury in the patients with cervical trauma and analyze its associated risk factors during the special heating season in North China. Methods This cross-sectional study investigated predictors for cervical spine injury in cervical trauma patients using retrospectively collected data of Hebei Provincial Orthopaedic Hospital from 11/2011 to 02/2012, and 11/2012 to 02/2013. Binary logistic regression analysis was used to determine risk factors for cervical fractures/dislocations or cord injury. Results A total of 106 patients were admitted into this study. Of all, 34 patients (32.1%) were treated from 11/2011 to 02/2012 and 72 patients (67.9%) from 11/2012 to 02/2013. The mean age was 41.9±13.3 years old; 85 patients (80.2%) were male and 82 (77.4%) from rural areas. Eighty patients (75.5%) were caused by fall including 45 (42.5%) by severe fall (>2 m). Sixty-five patients (61.3%) of all suffered injuries to other body regions and 32 (30.2%) got head injury. Thirty-one patients (29.2%) sustained cervical cord injury with cervical fractures/dislocations. Twenty-six (83.9%) of cervical cord injury patients were from rural areas and 24 (77.4%) of those resulted from fall including 15 (48.4%) from severe fall (>2 m). Logistic regression displayed that age (OR, 1.47; 95% CI, 1.05–2.07), head injury (OR, 5.63; 95% CI, 2.23–14.26), were risk factors for cervical cord injury and snowing (OR, 8.25; 95% CI, 2.26–30.15) was a risk factor for cervical spine injury due to severe fall (>2 m). Conclusions The elder male patients and patients with head trauma are high-risk population for cervical cord injury. As a seasonal factor, snowing during heating season is of note a risk factor for cervical spine injury resulting from severe fall (>2 m) in the patients with cervical trauma in North China. PMID:24223795

  12. Radar cross section of insects

    NASA Astrophysics Data System (ADS)

    Riley, J. R.

    1985-02-01

    X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

  13. Radar Cross Section Measurements

    DTIC Science & Technology

    1986-09-30

    Radar 54 17. Measured Range Sidelobe Performance of Chirp Radar 56 18. Range and Cross Range Image of Target Dror.’ŕ Vehicle 57 19. Incoherent rms...the measured range resolution, 4.9 in, closely agrees with the theoretical performance for this weighting. The measured range sidelobe performance...Interval 4.89in. 2% kHz 300 kHz 310 kHz (b) Expanded Scale + 5 ft from Target Figure 17. Measured Range Sidelobe Performance of

  14. XCOM: Photon Cross Sections Database

    National Institute of Standards and Technology Data Gateway

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  15. Cross sections at hadron colliders

    SciTech Connect

    Paige, F.E.

    1982-01-01

    The predicted cross sections are given for new Z'/sup 0/ bosons, for the Drell-Yan continuum of ..mu../sup +/..mu../sup -/ pairs, for high p/sub T/ hadron jets, for high p/sub T/ single photons, and for the associated production of heavy quarks. These processes have been selected not to cover the most interesting physics, but to provide a representative selection of cross sections for which to compare various energies and luminosities.

  16. Accurate Cross Sections for Microanalysis

    PubMed Central

    Rez, Peter

    2002-01-01

    To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. PMID:27446747

  17. Prevalence of metabolic syndrome and its components among men with and without clinical benign prostatic hyperplasia: a large, cross-sectional, UK epidemiological study.

    PubMed

    DiBello, Julia R; Ioannou, Chris; Rees, Jonathan; Challacombe, Ben; Maskell, Joe; Choudhury, Nurul; Kastner, Christof; Kirby, Mike

    2016-05-01

    To compare the prevalence of metabolic syndrome and the components of metabolic syndrome in men aged ≥50 years with and without clinical benign prostatic hyperplasia (BPH). This was a cross-sectional study using the UK Clinical Practice Research Datalink (CPRD). Men were selected from the CPRD who were aged ≥50 years and still registered as of 31 December 2011. Cohort 1 included men with clinical BPH, and cohort 2 men without clinical BPH who were matched 1:1 to those in cohort 1 by general practice, year of birth and previous years of available history (1-<2, 2-<3, 3-<4, ≥4 years of available history). The prevalence of metabolic syndrome and its components (for men alive and still registered in the CRPD as of 31 December 2011) was calculated using all available history (lifetime prevalence) and medical history from 2010 and 2011 (current prevalence). Crude odds ratios and 95% confidence intervals for the occurrence of metabolic syndrome and the occurrence of the components of metabolic syndrome were calculated by comparing men with and without BPH. A total of 26.5% of men with clinical BPH had metabolic syndrome compared with 20.9% of matched controls without clinical BPH (absolute difference 5.6%; P < 0.001); men with clinical BPH were therefore significantly more likely to have metabolic syndrome than matched controls without clinical BPH. Significantly greater proportions of men with clinical BPH also had each component of metabolic syndrome compared with matched controls without clinical BPH. The presence of clinical BPH was associated with a 37% increased odds of having metabolic syndrome (for both lifetime prevalence and current prevalence) compared with matched controls without clinical BPH. There is a significant cross-sectional association between clinical BPH and metabolic syndrome in the UK primary care population. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  18. Neutrino cross-sections: Experiments

    SciTech Connect

    Sánchez, F.

    2015-07-15

    Neutrino-nucleus cross-sections are as of today the main source of systematic errors for oscillation experiments together with neutrino flux uncertainties. Despite recent experimental and theoretical developments, future experiments require even higher precisions in their search of CP violation. We will review the experimental status and explore possible future developments required by next generation of experiments.

  19. Photoneutron cross sections for Au

    SciTech Connect

    Itoh, O.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Kamata, M.; Toyokawa, H.; Harada, H.; Kitatani, F.; Goko, S.; Nair, C.; Lui, Y.-W.

    2011-10-28

    Photoneutron cross sections were measured for Au in the entire energy range of the ({gamma},n) channel based on a direct neutron-counting technique with quasimonochromatic {gamma} rays produced in inverse Compton-scattering of laser photons with relativistic electrons. We present results of the measurement in comparison with the past data.

  20. Epidemiology of Diabetic Foot Ulcers and Amputations in Romania: Results of a Cross-Sectional Quality of Life Questionnaire Based Survey

    PubMed Central

    Bondor, Cosmina I.; Veresiu, Ioan A.; Florea, Bogdan; Vinik, Etta J.; Vinik, Aaron I.; Gavan, Norina A.

    2016-01-01

    This is a post hoc analysis of quality of life in diabetic neuropathy patients in a cross-sectional survey performed in 2012 in Romania, using the Norfolk QOL-DN in which 21,756 patients with self-reported diabetes were enrolled. This current analysis aims to expand research on the diabetic foot and to provide an update on the number of foot ulcers found in Romania. Of the 21,174 patients included in this analysis, 14.85% reported a history of foot ulcers and 3.60% reported an amputation. The percentage of neuropathy patients with foot ulcers increased with age; the lowest percentage was observed in the 20–29-year age group (6.62%) and the highest in the 80–89-year age group (17.68%). The highest number of amputations was reported in the 70–79-year age group (largest group). Compared to patients without foot ulcers, those with foot ulcers had significantly higher scores for total DN and all its subdomains translating to worse QOL (p < 0.001). This analysis showed a high rate of foot ulcers and amputations in Romanian diabetic patients. It underscores the need for implementation of effective screening and educational programs. PMID:27019852

  1. Epidemiological profile of hospitalised injuries among electric bicycle riders admitted to a rural hospital in Suzhou: a cross-sectional study.

    PubMed

    Du, Wei; Yang, Jie; Powis, Brent; Zheng, Xiaoying; Ozanne-Smith, Joan; Bilston, Lynne; He, JingLin; Ma, Ting; Wang, Xiaofei; Wu, Ming

    2014-04-01

    Police reports indicate an increasing burden of electric bike (E-bike) casualties in China; however, hospitalised injury data have not been reported. The aim of the present work was to describe hospitalised injury patterns for E-bikers involved in road crashes and explore injury risk disparities among them. For the period October 2010 to April 2011, this cross-sectional study retrospectively collected information for hospitalised E-bikers involved in road crashes from hospital records, in Suzhou China, using the International Classification of Diseases, 10th revision (ICD-10) injury diagnosis codes. Injury nature and body region were further categorised using ICD-10 codes. Multivariate logistic regression was used to assess the risk of specific injury types. We found that hospitalised E-biker injuries (n=323) accounted for 57.2% of road traffic hospitalisations over the 6-month study period. The average age, length of stay and hospitalisation cost were 43.8 years, 10.0 days and ¥8229 (US$1286), respectively. Fractures and head injuries were common. The odds of traumatic brain injuries were significantly elevated for night-time E-bike crashes and incidents other than colliding with motor vehicles. These findings confirm E-bike injuries as an important population health problem and identify elevated injury odds in different E-biker groups. Future injury prevention initiatives should include encouraging helmet use among E-bikers.

  2. The clinical epidemiology of depression in palliative care and the predictive value of somatic symptoms: cross-sectional survey with four-week follow-up.

    PubMed

    Rayner, Lauren; Lee, William; Price, Annabel; Monroe, Barbara; Sykes, Nigel; Hansford, Penny; Higginson, Irene J; Hotopf, Matthew

    2011-04-01

    This cross-sectional survey aimed to determine the prevalence and remission of depression in patients receiving palliative care and to ascertain the predictive value of somatic symptoms in making the diagnosis. Three hundred consecutive patients were interviewed within one week of their initial assessment by a specialist nurse at a palliative care service with in-patient and homecare facilities in south London, UK. Depression was assessed using the PRIME-MD PHQ-9. Presence of somatic symptoms (fatigue, sleep disturbance, poor appetite) was determined using the EORTC-QLQ-C30 quality of life questionnaire. Fifty-eight (19.3% [15.3 to 23.3]) patients met criteria for Major Depressive Disorder; 109 (36.3% [32.3 to 40.3]) met criteria for 'Any depressive syndrome'. Patients with Major Depressive Disorder were more likely to be male, and to have non-malignant disease, pain, poor performance status and desire for an early death. Of those patients with Major Depressive Disorder at baseline, 69% (27/39) had remitted four weeks later. Of those not depressed at baseline, 11% (19/174) met criteria for depression at follow-up. The positive predictive values of sleep disturbance, poor appetite and fatigue were low (<24%), whereas the negative predictive values of these symptoms were high (>89%). The high prevalence of depression in palliative care attests to the need for psychological assessment and support. Depression in patients receiving palliative care is unstable, suggesting that symptoms should be carefully monitored.

  3. Epidemiology of Diabetic Foot Ulcers and Amputations in Romania: Results of a Cross-Sectional Quality of Life Questionnaire Based Survey.

    PubMed

    Bondor, Cosmina I; Veresiu, Ioan A; Florea, Bogdan; Vinik, Etta J; Vinik, Aaron I; Gavan, Norina A

    2016-01-01

    This is a post hoc analysis of quality of life in diabetic neuropathy patients in a cross-sectional survey performed in 2012 in Romania, using the Norfolk QOL-DN in which 21,756 patients with self-reported diabetes were enrolled. This current analysis aims to expand research on the diabetic foot and to provide an update on the number of foot ulcers found in Romania. Of the 21,174 patients included in this analysis, 14.85% reported a history of foot ulcers and 3.60% reported an amputation. The percentage of neuropathy patients with foot ulcers increased with age; the lowest percentage was observed in the 20-29-year age group (6.62%) and the highest in the 80-89-year age group (17.68%). The highest number of amputations was reported in the 70-79-year age group (largest group). Compared to patients without foot ulcers, those with foot ulcers had significantly higher scores for total DN and all its subdomains translating to worse QOL (p < 0.001). This analysis showed a high rate of foot ulcers and amputations in Romanian diabetic patients. It underscores the need for implementation of effective screening and educational programs.

  4. Epidemiology of symptoms of dry eye disease (DED) in Jordan: A cross-sectional non-clinical population-based study.

    PubMed

    Bakkar, May M; Shihadeh, Wisam A; Haddad, Mera F; Khader, Yousef S

    2016-06-01

    To describe the prevalence of dry eye disease (DED) symptoms and to identify associated risk factors in a general non-clinical population in Jordan. In this cross-sectional study, participants were selected randomly from the general non-clinical population in Jordan. Participants aged 18 years or over completed the Arabic version of Ocular Surface Disease Index (OSDI) questionnaire on dry eye symptoms. The OSDI questionnaire was completed by 1039 subjects (609 female and 430 male). The mean OSDI score for the study population was 27, with 59% of subjects showed OSDI score ≥20 (a cut off score for mild DED symptoms). Females showed significantly higher mean OSDI score than males in the older age group (p=0.01). The prevalence of all dryness symptoms was markedly reported in older age group >45 years and contact lens wearers (p<0.05). The most commonly reported DED symptom was sensitivity to light and intense symptoms were markedly reported during windy conditions. Vision-related quality of life was also affected in subjects with dryness symptoms. Working with computers and ATM was among those that highly affected. The results show that symptoms of dry eye were prevalent in this non-clinical population. Contact lenses wear and older age were found to be associated with dry eye symptoms. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. Oral health-related quality of life, sense of coherence and dental anxiety: an epidemiological cross-sectional study of middle-aged women.

    PubMed

    Boman, Ulla Wide; Wennström, Anette; Stenman, Ulrika; Hakeberg, Magnus

    2012-06-18

    Few publications report on the relationship between salutogenesis, as measured by the concept of sense of coherence, and oral health-related quality of life. Even less information is to be found when the behavioural aspect of dental anxiety is added. The aim of the present study was to evaluate how oral health-related quality of life is related to sense of coherence and dental anxiety. The study had a cross-sectional design and included 500 randomly selected women in Gothenburg, Sweden, 38 and 50 years of age, from health examinations in 2004-05. The survey included questionnaires covering global questions concerning socio-economic status, oral health/function and dental care behaviour, and tests of oral health-related quality of life, sense of coherence, and dental anxiety. High dental anxiety and low sense of coherence predicted low oral health-related quality of life. In addition, socioeconomic status as measured by income, perceived oral functional status as captured by chewing ability and self-reported susceptibility to periodontal disease were also important predictors of oral health-related quality of life. Dental anxiety and sense of coherence had an inverse relationship with regard to oral health-related quality of life. These associations were stronger than other risk factors for low oral health-related quality of life.

  6. Sero-Epidemiological Study of Hepatitis E Virus among Thalassemia as High Risk Patients: A Cross-Sectional Survey in Jahrom, Southern, Iran

    PubMed Central

    Jahromi, Abdolreza Sotoodeh; Ahmadi-vasmehjani, Abbas; Zabetian, Hassan; Hakimelahi, Hossein; Yusefi, Alireza; Sanie, Mohammad Sadegh; Jahromi, Somayehsadat Talebnia; Ghanei, Masoud; Sapidkar, Abdolali; Erfanian, Saiedeh; Madani, Abdolhossien; Kafilzadeh, Farshid; Kargar, Mohammad; Hojjat-Farsangi, Mohammad

    2016-01-01

    Hepatitis E virus (HEV) could be cause of viral hepatitis in the developing countries and cause severe epidemics. According to other studies, blood transfusion as a probable route of HEV infection has been suggested. An infection with hepatitis agents such as HEV causes active liver failure in multi-transfusion patients in particular thalassemia. The purpose of this study determines the seropositivity of anti-HEV antibodies in thalassemia individuals in Jahrom. In a cross-sectional study, sera from 110 thalassemia were collected between 2013 and 2014. Enzyme-linked immunosorbent assay (ELISA) method was performed to detection of anti-HEV antibodies. Individuals’ data were collected such as, demographic and clinical, for statistical analysis. Our results show that 10% and 1.8% of the enrolled patients were HEV Ig-G and Ig-M positive antibodies respectively. In addition, there was statiscally significant difference in age groups for prevalence of anti-HEV Ig-G (P = 0.01). Also the serum levels of liver enzymes such as ALT and AST in the HEV Ig-G and Ig-M positive samples were significantly higher than anti-HEV negative samples. But there were no significant difference between sex and splenectomy with anti-HEV positive samples. The results indicate more study are needed to assess HEV screening of blood products to these patients that those have a probably risk of exposure to HEV especially in higher years old. PMID:27157168

  7. Epidemiology of HPV infection and current status of cervical cancer prevention in Greece: final results of the LYSISTRATA cross-sectional study.

    PubMed

    Agorastos, Theodoros; Chatzistamatiou, Kimon; Zafrakas, Menelaos; Siamanta, Vagia; Katsamagkas, Taxiarchis; Constantinidis, Theodoros C; Lampropoulos, Alexandros F

    2014-09-01

    The objective of this study was to assess the overall prevalence of the human papilloma virus (HPV) infection and distribution of high-risk HPV (hrHPV) types in Greece and evaluate the participation of women in primary and secondary cervical cancer prevention. This was a prospective, cross-sectional study carried out between October 2005 and January 2011 in Greece; 5379 women filled out the study questionnaire anonymously. 5107 women underwent cervical HPV-DNA testing, either by Hybrid Capture 2, followed by restriction fragment length polymorphism-PCR, or by the Abbott Real-Time High-Risk HPV test. Overall, 5.8% (295/5107) of women were positive for hrHPV infection. The most common hrHPV type was HPV-16 (24.8% among infected women; 1.4% overall), followed by HPV types 31, 35, 53, 18, 51, 56, 58, 52, 39, 66, 45, 33, 59, and 68. In respect to primary prevention of cervical cancer, acceptance of anti-HPV vaccination appeared to decrease over time (from 85-89.9% annually during 2005-2008 to 64.4-60.5% during 2009-2010, P<0.001). In respect to secondary prevention, only 30.3% of women had regular (annually for more than 5 years) Pap smears; regular gynecologic examinations, Papanicolaou testing, and knowledge of HPV were all associated with various demographic parameters (age, education, place of residence, occupation, and income). The prevalence of hrHPV infection in Greece is similar to that in other European countries; the most common type is HPV-16. The initially relatively high acceptance of HPV vaccination decreased after licensing of the vaccine. Demographic parameters appear to influence participation in cervical cancer screening.

  8. Integrated approach of nutritional and molecular epidemiology, mineralogical and chemical pollutant characterisation: the protocol of a cross-sectional study in women

    PubMed Central

    Barchitta, Martina; Quattrocchi, Annalisa; Maugeri, Andrea; Barone, Germana; Mazzoleni, Paolo; Catalfo, Alfio; De Guidi, Guido; Iemmolo, Maria; Crimi, Nunzio; Agodi, Antonella

    2017-01-01

    Introduction Environmentally-related health and disease are the result of the exposome, the totality of a person's environmental exposures, from all sources and routes, across their lifespan. Epigenetic phenomena, including DNA methylation, can be potentially modified by environmental and lifestyle factors, and result in environmental reprogramming of the genome for exposed individuals and for future generations of offspring. Objective The objective of the project is to evaluate the risk of DNA hypomethylation due to air pollution, Mediterranean diet adherence, folate intake, and demographic and socioeconomic factors, in healthy women living in the metropolitan area of Catania, Italy. Methods and analysis Non-pregnant healthy women will be enrolled in a cross-sectional study. Sociodemographic, lifestyle and dietary intake information will be collected. LINE-1 methylation will be measured by pyrosequencing. The participants' home addresses will be geocoded and each woman will be assigned to the closest monitoring station for particulate matter (PM) exposure assessment. Mineralogical-chemical characterisation of PM and cellular model assays will be performed. An integrated approach will be designed to estimate the combined possible effect of air pollution, Mediterranean diet adherence, folate intake and other lifestyle characteristics on LINE-1 methylation levels. Ethics and dissemination The project has been approved by the ethics committees of the involved institution and funded by the University of Catania (Finanziamento della Ricerca, FIR 2014). All participants will be fully informed of the purpose and procedures of the study, and signed written consents will be obtained. All the data collected will be treated confidentially and analysed in an aggregate and anonymous way. The results will be published in peer-reviewed journals and communicated to local public health agencies, in order to provide essential information for timely and effective public health action

  9. Integrated approach of nutritional and molecular epidemiology, mineralogical and chemical pollutant characterisation: the protocol of a cross-sectional study in women.

    PubMed

    Barchitta, Martina; Quattrocchi, Annalisa; Maugeri, Andrea; Barone, Germana; Mazzoleni, Paolo; Catalfo, Alfio; De Guidi, Guido; Iemmolo, Maria; Crimi, Nunzio; Agodi, Antonella

    2017-04-04

    Environmentally-related health and disease are the result of the exposome, the totality of a person's environmental exposures, from all sources and routes, across their lifespan. Epigenetic phenomena, including DNA methylation, can be potentially modified by environmental and lifestyle factors, and result in environmental reprogramming of the genome for exposed individuals and for future generations of offspring. The objective of the project is to evaluate the risk of DNA hypomethylation due to air pollution, Mediterranean diet adherence, folate intake, and demographic and socioeconomic factors, in healthy women living in the metropolitan area of Catania, Italy. Non-pregnant healthy women will be enrolled in a cross-sectional study. Sociodemographic, lifestyle and dietary intake information will be collected. LINE-1 methylation will be measured by pyrosequencing. The participants' home addresses will be geocoded and each woman will be assigned to the closest monitoring station for particulate matter (PM) exposure assessment. Mineralogical-chemical characterisation of PM and cellular model assays will be performed. An integrated approach will be designed to estimate the combined possible effect of air pollution, Mediterranean diet adherence, folate intake and other lifestyle characteristics on LINE-1 methylation levels. The project has been approved by the ethics committees of the involved institution and funded by the University of Catania (Finanziamento della Ricerca, FIR 2014). All participants will be fully informed of the purpose and procedures of the study, and signed written consents will be obtained. All the data collected will be treated confidentially and analysed in an aggregate and anonymous way. The results will be published in peer-reviewed journals and communicated to local public health agencies, in order to provide essential information for timely and effective public health action. Published by the BMJ Publishing Group Limited. For permission to

  10. Efficiency of Household Reactive Case Detection for Malaria in Rural Southern Zambia: Simulations Based on Cross-Sectional Surveys from Two Epidemiological Settings

    PubMed Central

    Searle, Kelly M.; Shields, Timothy; Hamapumbu, Harry; Kobayashi, Tamaki; Mharakurwa, Sungano; Thuma, Philip E.; Smith, David L.; Glass, Gregory; Moss, William J.

    2013-01-01

    Background Case detection and treatment are critical to malaria control and elimination as infected individuals who do not seek medical care can serve as persistent reservoirs for transmission. Methods Household malaria surveys were conducted in two study areas within Southern Province, Zambia in 2007 and 2008. Cross-sectional surveys were conducted approximately five times throughout the year in each of the two study areas. During study visits, adults and caretakers of children were administered a questionnaire and a blood sample was obtained for a rapid diagnostic test (RDT) for malaria. These data were used to estimate the proportions of individuals with malaria potentially identified through passive case detection at health care facilities and those potentially identified through reactive case finding. Simulations were performed to extrapolate data from sampled to non-sampled households. Radii of increasing size surrounding households with an index case were examined to determine the proportion of households with an infected individual that would be identified through reactive case detection. Results In the 2007 high transmission setting, with a parasite prevalence of 23%, screening neighboring households within 500 meters of an index case could have identified 89% of all households with an RDT positive resident and 90% of all RDT positive individuals. In the 2008 low transmission setting, with a parasite prevalence of 8%, screening neighboring households within 500 meters of a household with an index case could have identified 77% of all households with an RDT positive resident and 76% of all RDT positive individuals. Conclusions Testing and treating individuals residing within a defined radius from an index case has the potential to be an effective strategy to identify and treat a large proportion of infected individuals who do not seek medical care, although the efficiency of this strategy is likely to decrease with declining parasite prevalence. PMID

  11. Efficiency of household reactive case detection for malaria in rural Southern Zambia: simulations based on cross-sectional surveys from two epidemiological settings.

    PubMed

    Searle, Kelly M; Shields, Timothy; Hamapumbu, Harry; Kobayashi, Tamaki; Mharakurwa, Sungano; Thuma, Philip E; Smith, David L; Glass, Gregory; Moss, William J

    2013-01-01

    Case detection and treatment are critical to malaria control and elimination as infected individuals who do not seek medical care can serve as persistent reservoirs for transmission. Household malaria surveys were conducted in two study areas within Southern Province, Zambia in 2007 and 2008. Cross-sectional surveys were conducted approximately five times throughout the year in each of the two study areas. During study visits, adults and caretakers of children were administered a questionnaire and a blood sample was obtained for a rapid diagnostic test (RDT) for malaria. These data were used to estimate the proportions of individuals with malaria potentially identified through passive case detection at health care facilities and those potentially identified through reactive case finding. Simulations were performed to extrapolate data from sampled to non-sampled households. Radii of increasing size surrounding households with an index case were examined to determine the proportion of households with an infected individual that would be identified through reactive case detection. In the 2007 high transmission setting, with a parasite prevalence of 23%, screening neighboring households within 500 meters of an index case could have identified 89% of all households with an RDT positive resident and 90% of all RDT positive individuals. In the 2008 low transmission setting, with a parasite prevalence of 8%, screening neighboring households within 500 meters of a household with an index case could have identified 77% of all households with an RDT positive resident and 76% of all RDT positive individuals. Testing and treating individuals residing within a defined radius from an index case has the potential to be an effective strategy to identify and treat a large proportion of infected individuals who do not seek medical care, although the efficiency of this strategy is likely to decrease with declining parasite prevalence.

  12. Monitoring the effects of iodine prophylaxis in the adult population of southern Italy with deficient and sufficient iodine intake levels: a cross-sectional, epidemiological study.

    PubMed

    Bonofiglio, Daniela; Catalano, Stefania; Perri, Anna; Santoro, Marta; Siciliano, Lorenza; Lofaro, Danilo; Gallo, Massimiliano; Marsico, Stefania; Bruno, Rosalinda; Giordano, Cinzia; Barone, Ines; Andò, Sebastiano

    2017-01-01

    I prophylaxis is the most effective strategy to eradicate I deficiency disorders, but it has been shown to affect the thyroid disease pattern. In this study, we assessed the frequency of thyroid disorders in an adult population living in two areas of southern Italy after implementing I prophylaxis. To this aim, a cross-sectional, population-based study including 489 subjects from an I-deficient rural and an I-sufficient urban area of southern Italy was conducted. Thyroid ultrasound was performed on all participants, and urine and blood samples were collected from each subject. The levels of thyroid-stimulating hormone (TSH), thyroglobulin (TgAb) and thyroperoxidase antibodies (TPOAb), urinary I excretion (UIE), and thyroid volume and echogenicity were evaluated. We found that the median UIE was higher in the urban than in the rural area (P=0·004), whereas the prevalence of subjects affected by goitre was higher in the rural compared with the urban area (P=0·003). Positive TgAb rather than TPOAb were more frequent in subjects from the urban area compared with the rural area (P=0·009). The hypoechoic pattern at thyroid ultrasound (HT-US) was similar between the two areas, but TgAb were significantly higher (P=0·01) in HT-US subjects from the urban area. The frequency of elevated TSH did not differ between the two screened populations, and no changes were found for TgAb positivity in subjects with high TSH in the urban compared with the rural area. Our findings support that the small risks of I supplementation are far outweighed by the substantial benefits of correcting I deficiency, although continued monitoring of populations is necessary.

  13. Cross Sections for Planetary Escape

    NASA Astrophysics Data System (ADS)

    Tully, C.

    2001-05-01

    Energetic charged-particle bombardment, dissociative recombination and photodissociation processes produce energetic recoil atoms which heat the thermosphere and can lead to escape from a planet affecting the evolution of the atmosphere. In describing these processes by Monte Carlo methods, many of the critical cross sections are not available in the energy range of interest, a few eV to 1 keV. Here we present our recent results for elastic collision and collisional dissociation cross sections relevant to Titan, Triton, Europa and the terrestrial planets [1,2]. Elastic and diffusion cross sections were calculated using both quantum mechanical techniques and the semiclassical JWKB approximation for the collision of ground state oxygen atoms in the energy range 1-10eV [2]. This involved calculation of phase shifts for each of the 18 molecular energy states of O2 which separate to two ground state O atoms. For an O thermosphere the total elastic cross section is close to that typically assumed but the escape depths are shown to be larger than those typically used. Dissociation cross sections of N + N2 were calculated using a semiclassical method, in the energy range 0-30eV. This required treating the vibrational motion quantum mechanically while the rotational and the relative translational motion were treated classically. The evolution of the system was calculated by simultaneous propagation of the classical as well as the quantal degrees of freedom. The solution to the classical part was carried out by solving Hamilton equations of motion using an effective London-Eyring-Polanyi-Sato potential energy surface, calculated by Laganá et al [3]. Propagation of the quantal wavefunction was carried out by solving the time dependent Schrödinger equation using the split operator technique with the help of the fast fourier transform which was used to calculate the second derivatives arising from the kinetic energy operator. This work was supported by NASA's Planetary

  14. Clinical and epidemiological factors associated with methicillin resistance in community-onset invasive Staphylococcus aureus infections: prospective multicenter cross-sectional study in Korea.

    PubMed

    Kim, Eu Suk; Kim, Hong Bin; Kim, Gayeon; Kim, Kye-Hyung; Park, Kyung-Hwa; Lee, Shinwon; Choi, Young Hwa; Yi, Jongyoun; Kim, Chung Jong; Song, Kyoung-Ho; Choe, Pyoeng Gyun; Kim, Nam-Joong; Lee, Yeong-Seon; Oh, Myoung-Don

    2014-01-01

    Successful empirical therapy of Staphylococcus aureus infections requires the ability to predict methicillin resistance. Our aim was to identify predictors of methicillin resistance in community-onset (CO) invasive S. aureus infections. Sixteen hospitals across Korea participated in this study from May to December 2012. We prospectively included cases of S. aureus infection in which S. aureus was isolated from sterile clinical specimens ≤ 72 hours after hospitalization. Clinical and epidemiological data were gathered and compared in methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) cases. Community-associated (CA) infections were defined as in previous studies. In total, there were 786 cases of community-onset S. aureus infection, 102 (13.0%) of which were CA-MRSA. In addition to known risk factors, exposure to 3rd generation cephalosporins in the past 6 months [odds ratio (OR), 1.922; 95% confidence interval (CI), 1.176-3.142] and close contact with chronically ill patients in the past month (OR, 2.647; 95% CI, 1.189-5.891) were independent risk factors for MRSA infection. However, no clinical predictors of CA-MRSA were identified. Methicillin resistance, CO infection, and appropriateness of empirical antibiotics were not significantly related to 30-day mortality. MRSA infection should be suspected in patients recently exposed to 3rd generation cephalosporins or chronically-ill patients. There were no reliable predictors of CA-MRSA infection, and mortality was not affected by methicillin resistance.

  15. Electron-Impact Ionization Cross Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  16. Big Five personality traits may inform public health policy and preventive medicine: Evidence from a cross-sectional and a prospective longitudinal epidemiologic study in a Swiss community.

    PubMed

    Hengartner, Michael P; Kawohl, Wolfram; Haker, Helene; Rössler, Wulf; Ajdacic-Gross, Vladeta

    2016-05-01

    Some evidence documents the importance of personality assessments for health research and practise. However, no study has opted to test whether a short self-report personality inventory may comprehensively inform health policy. Data were taken from a population-based epidemiologic survey in Zurich, Switzerland, conducted from 2010-2012. A short form of the Big Five Inventory was completed by n=1155 participants (54.4% women; mean age=29.6 years), while health-related outcomes were taken from a comprehensive semi-structured clinical interview. A convenience subsample averaging n=171 participants additionally provided laboratory measures and n=133 were subsequently followed-up at least once over a maximal period of 6 months. Personality traits, in particular high neuroticism and low conscientiousness, related significantly to poor environmental resources such as low social support (R(2)=0.071), health-impairing behaviours such as cannabis use (R(2)=0.071), and psychopathology, including negative affect (R(2)=0.269) and various mental disorders (R(2)=0.060-0.195). The proportion of total variance explained was R(2)=0.339 in persons with three or more mental disorders. Personality significantly related to some laboratory measures including total cholesterol (R(2)=0.095) and C-Reactive Protein (R(2)=0.062). Finally, personality prospectively predicted global psychopathological distress and vegetative symptoms over a 6-month observation period. Personality relates consistently to poor socio-environmental resources, health-impairing behaviours and psychopathology. We also found some evidence for an association with metabolic and immune functions that are assumed to influence health. A short personality inventory could provide valuable information for preventive medicine when used as a means to screen entire populations for distinct risk exposure, in particular with respect to psychopathology. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. An Epidemiological Profile of CrossFit Athletes in Brazil

    PubMed Central

    Sprey, Jan W.C.; Ferreira, Thiago; de Lima, Marcos V.; Duarte, Aires; Jorge, Pedro B.; Santili, Claudio

    2016-01-01

    Background: CrossFit is a conditioning and training program that has been gaining recognition and interest among the physically active population. Approximately 440 certified and registered CrossFit fitness centers and gyms exist in Brazil, with approximately 40,000 athletes. To date, there have been no epidemiological studies about the CrossFit athlete in Brazil. Purpose: To evaluate the profile, sports history, training routine, and presence of injuries among athletes of CrossFit. Study Design: Descriptive epidemiological study. Methods: This cross-sectional study was based on a questionnaire administered to CrossFit athletes from various specialized fitness centers in Brazil. Data were collected from May 2015 to July 2015 through an electronic questionnaire that included demographic data, level of sedentary lifestyle at work, sports training history prior to starting CrossFit, current sports activities, professional monitoring, and whether the participants experienced any injuries while practicing CrossFit. Results: A total of 622 questionnaires were received, including 566 (243 women [42.9%] and 323 men [57.1%]) that were completely filled out and met the inclusion criteria and 9% that were incompletely filled out. Overall, 176 individuals (31.0%) mentioned having experienced some type of injury while practicing CrossFit. We found no significant difference in injury incidence rates regarding demographic data. There was no significant difference regarding previous sports activities because individuals who did not practice prior physical activity showed very similar injury rates to those who practiced at any level. Conclusion: CrossFit injury rates are comparable to those of other recreational or competitive sports, and the injuries show a profile similar to weight lifting, power lifting, weight training, Olympic gymnastics, and running, which have an injury incidence rate nearly half that of soccer. PMID:27631016

  18. An Epidemiological Profile of CrossFit Athletes in Brazil.

    PubMed

    Sprey, Jan W C; Ferreira, Thiago; de Lima, Marcos V; Duarte, Aires; Jorge, Pedro B; Santili, Claudio

    2016-08-01

    CrossFit is a conditioning and training program that has been gaining recognition and interest among the physically active population. Approximately 440 certified and registered CrossFit fitness centers and gyms exist in Brazil, with approximately 40,000 athletes. To date, there have been no epidemiological studies about the CrossFit athlete in Brazil. To evaluate the profile, sports history, training routine, and presence of injuries among athletes of CrossFit. Descriptive epidemiological study. This cross-sectional study was based on a questionnaire administered to CrossFit athletes from various specialized fitness centers in Brazil. Data were collected from May 2015 to July 2015 through an electronic questionnaire that included demographic data, level of sedentary lifestyle at work, sports training history prior to starting CrossFit, current sports activities, professional monitoring, and whether the participants experienced any injuries while practicing CrossFit. A total of 622 questionnaires were received, including 566 (243 women [42.9%] and 323 men [57.1%]) that were completely filled out and met the inclusion criteria and 9% that were incompletely filled out. Overall, 176 individuals (31.0%) mentioned having experienced some type of injury while practicing CrossFit. We found no significant difference in injury incidence rates regarding demographic data. There was no significant difference regarding previous sports activities because individuals who did not practice prior physical activity showed very similar injury rates to those who practiced at any level. CrossFit injury rates are comparable to those of other recreational or competitive sports, and the injuries show a profile similar to weight lifting, power lifting, weight training, Olympic gymnastics, and running, which have an injury incidence rate nearly half that of soccer.

  19. Epidemiology of Emergent Madariaga Encephalitis in a Region with Endemic Venezuelan Equine Encephalitis: Initial Host Studies and Human Cross-Sectional Study in Darien, Panama

    PubMed Central

    Vittor, Amy Y.; Armien, Blas; Gonzalez, Publio; Carrera, Jean-Paul; Dominguez, Claudia; Valderrama, Anayansi; Glass, Greg E.; Beltran, Davis; Cisneros, Julio; Wang, Eryu; Castillo, Alex; Moreno, Brechla; Weaver, Scott C.

    2016-01-01

    Background Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology. Methods Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion. Results The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing

  20. Epidemiology of Emergent Madariaga Encephalitis in a Region with Endemic Venezuelan Equine Encephalitis: Initial Host Studies and Human Cross-Sectional Study in Darien, Panama.

    PubMed

    Vittor, Amy Y; Armien, Blas; Gonzalez, Publio; Carrera, Jean-Paul; Dominguez, Claudia; Valderrama, Anayansi; Glass, Greg E; Beltran, Davis; Cisneros, Julio; Wang, Eryu; Castillo, Alex; Moreno, Brechla; Weaver, Scott C

    2016-04-01

    Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology. Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion. The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing were risk factors for VEEV

  1. The burden of revision sinonasal surgery in the UK—data from the Chronic Rhinosinusitis Epidemiology Study (CRES): a cross-sectional study

    PubMed Central

    Philpott, Carl; Hopkins, Claire; Erskine, Sally; Kumar, Nirmal; Robertson, Alasdair; Farboud, Amir; Ahmed, Shahzada; Anari, Shahram; Cathcart, Russell; Khalil, Hisham; Jervis, Paul; Carrie, Sean; Kara, Naveed; Prinsley, Peter; Almeyda, Robert; Mansell, Nicolas; Sunkaraneni, Sankalp; Salam, Mahmoud; Ray, Jaydip; Panesaar, Jaan; Hobson, Jonathan; Clark, Allan; Morris, Steve

    2015-01-01

    Objectives The aim of this study was to investigate the surgical revision rate in patients with chronic rhinosinusitis (CRS) in the UK CRS Epidemiology Study (CRES). Previous evidence from National Sinonasal Audit showed that 1459 patients with CRS demonstrated a surgical revision rate 19.1% at 5 years, with highest rates seen in those with polyps (20.6%). Setting Thirty secondary care centres around the UK. Participants A total of 221 controls and 1249 patients with CRS were recruited to the study including those with polyps (CRSwNPs), without polyps (CRSsNPs) and with allergic fungal rhinosinusitis (AFRS). Interventions Self-administered questionnaire. Primary outcome measure The need for previous sinonasal surgery. Results A total of 651 patients with CRSwNPs, 553 with CRSsNPs and 45 with AFRS were included. A total of 396 (57%) patients with CRSwNPs/AFRS reported having undergone previous endoscopic nasal polypectomy (ENP), of which 182 of the 396 (46%) reported having received more than one operation. The mean number of previous surgeries per patient in the revision group was 3.3 (range 2–30) and a mean duration of time of 10 years since the last procedure. The average length of time since their first operation up to inclusion in the study was 15.5 years (range 0–74). Only 27.9% of all patients reporting a prior ENP had received concurrent endoscopic sinus surgery (ESS; n=102). For comparison, surgical rates in patients with CRSsNPs were significantly lower; 13% of cases specifically reported ESS, and of those only 30% reported multiple procedures (χ2 p<0.001). Conclusions This study demonstrated that there is a high burden of both primary and revision surgery in patients with CRS, worst in those with AFRS and least in those with CRSsNPs. The burden of revision surgery appears unchanged in the decade since the Sinonasal Audit. PMID:25926143

  2. Cross Sections: No. 1 Hold section at Fr 24 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No. 1 Hold section at Fr 24 Looking Fwd, No 1 Hold Section at Fr 28 Looking Aft, No 2 Hold Section at Fr 48 Looking Aft, No 3 Hold Section at Fr 70 Looking Aft, No 4 Hold Section at Fr 90 Looking Aft - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  3. Neutron cross sections: Book of curves

    SciTech Connect

    McLane, V.; Dunford, C.L.; Rose, P.F.

    1988-01-01

    Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs.

  4. Photoproduction total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, F.; García Canal, C. A.; Grau, A.; Pancheri, G.; Sciutto, S. J.

    2015-12-01

    The total photoproduction cross section at ultrahigh energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  5. SNL RML recommended dosimetry cross section compendium

    SciTech Connect

    Griffin, P.J.; Kelly, J.G.; Luera, T.F.; VanDenburg, J.

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  6. [Fast neutron cross section measurements

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  7. Cross Sections: No 6 Hold Section at Fr 178 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No 6 Hold Section at Fr 178 Looking Fwd, No 7 Hold Section at No 154 Looking Fwd, No 7 Hold Section at Fr 195 Looking Fwd Showing Trans 194, No 7 Hold Section at Fr 198 Looking Fwd - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  8. The role of live poultry movement and live bird market biosecurity in the epidemiology of influenza A (H7N9): A cross-sectional observational study in four eastern China provinces.

    PubMed

    Zhou, Xiaoyan; Li, Yin; Wang, Youming; Edwards, John; Guo, Fusheng; Clements, Archie C A; Huang, Baoxu; Magalhaes, Ricardo J Soares

    2015-10-01

    A new reassortant influenza A (H7N9) virus emerged early 2013 in eastern China. Exposure to H7N9 infected poultry at live bird markets (LBM) was implicated as the main risk factor for human infection. We aimed to identify the role of LBM biosecurity indicators and poultry movement in the affected areas. A cross-sectional survey was carried out in 24 LBMs at the beginning of H7N9 outbreak in all affected provinces. We used univariable analysis to identify the biosecurity factors associated with the H7N9 presence in LBMs and social network and spatial analysis to quantify the connectivity and geographic variation in the connectivity of poultry movements. Chickens were the predominant poultry species traded by affected LBMs. The presence of H7N9 in LBMs was significantly associated with the type of LBM and with LBMs that sold chicken to other markets. The chicken movements were significantly spatially clustered and was highest in counties from Jiangsu and Anhui provinces. LBM biosecurity and chicken movement played an important role in the emergence of H7N9. This study identified highly connected areas in eastern China which continue to report human infections highlighting candidate areas for more detailed epidemiological investigations. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  9. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  10. Cross Sections for Electron Collisions with Acetylene

    NASA Astrophysics Data System (ADS)

    Song, Mi-Young; Yoon, Jung-Sik; Cho, Hyuck; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2017-03-01

    Cross section data are compiled from the literature for electron collisions with the acetylene (HCCH) molecule. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2016.

  11. Cross Sections for Electron Collisions with Methane

    SciTech Connect

    Song, Mi-Young Yoon, Jung-Sik; Cho, Hyuck; Itikawa, Yukikazu; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  12. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  13. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  14. Theoretical antideuteron-nucleus absorptive cross sections

    NASA Technical Reports Server (NTRS)

    Buck, W. W.; Norbury, J. W.; Townsend, L. W.; Wilson, J. W.

    1993-01-01

    Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

  15. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  16. Neutron capture cross section of 102Pd

    NASA Astrophysics Data System (ADS)

    Duncan, C. L.; Krane, K. S.

    2005-05-01

    The cross sections for radiative neutron capture by 102Pd have been deduced from a measurement of the γ rays emitted by 17.0-d 103Pd. The thermal cross section has been determined to be σ=1.82±0.20 b, and the effective resonance integral is I=23±4 b. We also report thermal and resonance capture cross sections for 108Pd and note possible inconsistencies with the presently accepted values of the 110Pd cross sections.

  17. Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with Arch; Part Long Section Showing Inside of External Side Wall; East Entrance; Part Side South External; Part Reflected Plan of Soffite of Floor; Part Reflected Plan of Soffite of Roof - Blenheim Covered Bridge, Spanning Schoharie River, North Blenheim, Schoharie County, NY

  18. Neutrino flux predictions for cross section measurements

    SciTech Connect

    Hartz, Mark

    2015-05-15

    Experiments that measure neutrino interaction cross sections using accelerator neutrino sources require a prediction of the neutrino flux to extract the interaction cross section from the measured neutrino interaction rate. This article summarizes methods of estimating the neutrino flux using in-situ and ex-situ measurements. The application of these methods by current and recent experiments is discussed.

  19. Neutrino Cross Sections at Solar Energies

    NASA Astrophysics Data System (ADS)

    Strigari, Louis

    2017-01-01

    I will review neutrino nucleus cross section measurements and uncertainties for energies applicable to solar neutrinos. I will discuss how these cross sections are important for interpreting solar neutrino experimental data, and highlight the most important neutrino-nucleus interactions that will be relevant for forthcoming dark matter direct detection experiments. NSF PHY-1522717.

  20. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  1. Cross-sectional anatomy for computed tomography

    SciTech Connect

    Farkas, M.L.

    1988-01-01

    This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations.

  2. International Evaluation of Neutron Cross Section Standards

    NASA Astrophysics Data System (ADS)

    Carlson, A. D.; Pronyaev, V. G.; Smith, D. L.; Larson, N. M.; Chen, Zhenpeng; Hale, G. M.; Hambsch, F.-J.; Gai, E. V.; Oh, Soo-Youl; Badikov, S. A.; Kawano, T.; Hofmann, H. M.; Vonach, H.; Tagesen, S.

    2009-12-01

    Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the neutron cross section standards was finished in 1987 and disseminated as the NEANDC/INDC and ENDF/B-VI standards. R-matrix model fits for the light elements and non-model least-squares fits for all the cross sections in the evaluation were the basis of the combined fits for all of the data. Some important reactions and constants are not standards, but they assist greatly in the determination of the standard cross sections and reduce their uncertainties - these data were also included in the combined fits. The largest experimental database used in the evaluation was prepared by Poenitz and included about 400 sets of experimental data with covariance matrices of uncertainties that account for all cross-energy, cross-reaction and cross-material correlations. For the evaluation GMA, a least-squares code developed by Poenitz, was used to fit all types of cross sections (absolute and shape), their ratios, spectrum-averaged cross sections and thermal constants in one full analysis. But, the uncertainties derived in this manner, and especially those obtained in the R-matrix model fits, have been judged to be too low and unrealistic. These uncertainties were substantially increased prior to their release in the recommended data files of 1987. Modified percentage uncertainties were reassigned by the United States Cross Section Evaluation Working Group's Standards Subcommittee for a wide range of energies, and no covariance (or correlation) matrices were supplied at that time. The need to re-evaluate the cross section standards is based on the appearance of a significant amount of precise

  3. Nucleon-Nucleon Total Cross Section

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2008-01-01

    The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

  4. Ultrahigh-energy photonuclear cross sections

    SciTech Connect

    Gandhi, R.; Sarcevic, I.; Burrows, A. ); Durand, L.; Pi, H. )

    1990-07-01

    We present results of calculations of the total inelastic photon-air cross sections at ultrahigh energies (up to 10{sup 8} GeV in the laboratory) of relevance to on-going cosmic-ray experiments. The calculations take into account the high-energy QCD structure of the photon and are performed for a variety of photon and proton structure functions. The total inelastic photon-air cross section is obtained from the photon-proton jet cross section via an eikonalization procedure using a QCD-based diffractive model. The results are discussed in the context of the apparent excess muon content of air showers associated with point sources.

  5. K-shell photoionization cross-sections.

    NASA Technical Reports Server (NTRS)

    Daltabuit, E.; Cox, D. P.

    1972-01-01

    Approximate values for the threshold energies, threshold cross sections, and energy dependence of the cross sections for K-shell photoionization are tabulated for H, He, C, N, O, Ne, Mg, Si, and S in all stages of ionization. The approximation of these data is based on the assumptions that the threshold energy is a simple function of the nuclear charge and the number of electrons present in the atom, and that the threshold values and energy dependence of the cross sections are determined only by the threshold energy.

  6. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  7. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Henderson, R.; Jandel, M.; Kwan, E.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Wu, C. Y.

    2014-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) has been used to measure the 239Pu(n,γ) cross section from 10 eV to the keV region. Three experimental run conditions were used to characterize the prompt fission γ-ray spectrum across the entire energy regime, measure the cross section in the resolved resonance region, and obtain necessary count rate well into the keV region. The preliminary cross sections are in good agreement with current evaluations from 10 eV to 80 keV.

  8. Allergic conjunctivitis: a cross-sectional study.

    PubMed

    Leonardi, A; Piliego, F; Castegnaro, A; Lazzarini, D; La Gloria Valerio, A; Mattana, P; Fregona, I

    2015-06-01

    Ocular allergy is a common disease in daily practice. A cross-sectional study was conducted to evaluate clinical aspects of and therapeutic approaches to ocular allergy in Italy. Of the 3685 patients affected by ocular allergy and enrolled by 304 ophthalmologists nationally, 3545 were eligible to be included in the statistical analysis. A questionnaire was administered in office to record demographic data, comorbidities, trigger factors, number of conjunctivitis episodes, and past treatments. Signs and symptoms were graded according to their severity, frequency, and duration. Mean age of enrolled patients was 38 ± 19 years. Seasonal allergic conjunctivitis (55% of patients) was equally distributed among the different age groups, while perennial allergic conjunctivitis (18%) increased with age and vernal keratoconjunctivitis (9%) was more frequent under the age of 18. Itching and redness were reported in 90% and 85%, respectively; lid skin involvement was observed in 22% of cases and keratitis in 11%. Pollen sensitivities were indicated as the most frequent triggers; however, exposure to non-specific environmental conditions, pollutants, and cigarette smoke was frequently reported. Only 35% of patients underwent a diagnostic evaluation of specific allergic sensitization, with positive allergy tests found in 82% of this subset. With regard to treatment, topical decongestants were used in 43% of patients, corticosteroids in 41%, antihistamines in 29%, systemic antihistamines in 27%, and mast cell stabilizers in 15%. This survey provided useful epidemiological information regarding the clinical characteristics and treatment options of a large cohort of patients affected by different forms of ocular allergy. An understanding of ocular allergic disease, its incidence, demographics, and treatment paradigms provides important information towards understanding its pharmacoeconomics and burden on the national health system. © 2015 John Wiley & Sons Ltd.

  9. Energy dependence of fusion cross sections

    SciTech Connect

    Bang, J.M.; Ferreira, L.S.; Maglione, E.; Hansteen, J.M.

    1996-01-01

    Observed enhancements of fusion cross sections at low energies are explained as caused by an underestimate of beam energy due to an overestimate of the stopping energy loss. {copyright} {ital 1996 The American Physical Society.}

  10. A nuclear cross section data handbook

    SciTech Connect

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  11. Bibliography of photoabsorption cross-section data

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Kieffer, L. J.

    1970-01-01

    This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

  12. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1982-01-01

    A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

  13. Dijet cross sections in photoproduction at HERA

    NASA Astrophysics Data System (ADS)

    ZEUS Collaboration; Breitweg, J.; et al.

    Dijet cross sections are presented using photoproduction data obtained with the ZEUS detector during 1994. These measurements represent an extension of previous results, as the higher statistics allow cross sections to be measured at higher jet transverse energy ( ETjet). Jets are identified in the hadronic final state using three different algorithms, and the cross sections compared to complete next-to-leading order QCD calculations. Agreement with these calculations is seen for the pseudorapidity dependence of the direct photon events with ETjet > 6 GeV and of the resolved photon events with ETjet > 11 GeV. Calculated cross sections for resolved photon processes with 6 GeV < ETjet < 11 GeV lie below the data.

  14. Capture cross sections on unstable nuclei

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Escher, J. E.; Scielzo, N.; Bedrossian, P.; Ilieva, R. S.; Humby, P.; Cooper, N.; Goddard, P. M.; Werner, V.; Tornow, W.; Rusev, G.; Kelley, J. H.; Pietralla, N.; Scheck, M.; Savran, D.; Löher, B.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Tsoneva, N.; Goriely, S.

    2017-09-01

    Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

  15. Benchmark cross sections for bottom quark production

    SciTech Connect

    Berger, E.L.

    1988-01-07

    A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.

  16. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  17. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.

    1984-01-01

    A solution is presented for the backscatter (monostatic) radar cross section of dielectric disks of arbitrary shape, thickness, and dielectric constant. The result is obtained by employing a Kirchhoff-type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner will be shown to agree with known results in the special cases of normal incidence, thin disks, and perfect conductivity. It will also be shown that the solution can be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff-type approximation without additional assumptions.

  18. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  19. High precision neutron inelastic cross section measurements

    NASA Astrophysics Data System (ADS)

    Olacel, A.; Belloni, F.; Borcea, C.; Boromiza, M.; Dessagne, Ph.; Henning, G.; Kerveno, M.; Negret, A.; Nyman, M.; Pirovano, E.; Plompen, A.

    2017-06-01

    High precision neutron inelastic scattering cross section data are very important for the development of the new generation of nuclear reactors (Gen IV). Our experiments, performed using the GELINA neutron source and the GAINS spectrometer of the European Commission Joint Research Center, Geel, produce highly reliable and precise cross section data. We will present the details of the setup and the data analysis technique allowing production of such unique results, and we will show examples of two experimental results.

  20. Reaction cross sections of unstable nuclei

    SciTech Connect

    Ozawa, Akira

    2006-11-02

    Experimental studies on reaction cross sections are reviewed. The recent developments of radioactive nuclear beams have enabled us to measure reaction cross-sections for unstable nuclei. Using Glauber-model analysis, effective nuclear matter density distributions of unstable nuclei can be studied. Recent measurements in RIBLL at IMP and RIPS at RIKEN are introduced. The effective matter density distributions for 14-18C are also mentioned.

  1. Shuttle orbiter radar cross-sectional analysis

    NASA Technical Reports Server (NTRS)

    Cooper, D. W.; James, R.

    1979-01-01

    Theoretical and model simulation studies on signal to noise levels and shuttle radar cross section are described. Pre-mission system calibrations, system configuration, and postmission system calibration of the tracking radars are described. Conversion of target range, azimuth, and elevation into radar centered east north vertical position coordinates are evaluated. The location of the impinging rf energy with respect to the target vehicles body axis triad is calculated. Cross section correlation between the two radars is presented.

  2. 46 CFR 64.25 - Cross section.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Cross section. 64.25 Section 64.25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING...) Circular; or (b) Other than circular and stress analyzed experimentally by the method contained in UG-101...

  3. 46 CFR 64.25 - Cross section.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Cross section. 64.25 Section 64.25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING...) Circular; or (b) Other than circular and stress analyzed experimentally by the method contained in UG-101...

  4. abo-cross: Hydrogen broadening cross-section calculator

    NASA Astrophysics Data System (ADS)

    Barklem, P. S.; Anstee, S. D.; O'Mara, B. J.

    2015-07-01

    Line broadening cross sections for the broadening of spectral lines by collisions with neutral hydrogen atoms have been tabulated by Anstee & O'Mara (1995), Barklem & O'Mara (1997) and Barklem, O'Mara & Ross (1998) for s-p, p-s, p-d, d-p, d-f and f-d transitions. abo-cross, written in Fortran, interpolates in these tabulations to make these data more accessible to the end user. This code can be incorporated into existing spectrum synthesis programs or used it in a stand-alone mode to compute line broadening cross sections for specific transitions.

  5. Reduction Methods for Total Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Gomes, P. R. S.; Mendes Junior, D. R.; Canto, L. F.; Lubian, J.; de Faria, P. N.

    2016-03-01

    The most frequently used methods to reduce fusion and total reaction excitation functions were investigated in a very recent paper Canto et al. (Phys Rev C 92:014626, 2015). These methods are widely used to eliminate the influence of masses and charges in comparisons of cross sections for weakly bound and tightly bound systems. This study reached two main conclusions. The first is that the fusion function method is the most successful procedure to reduce fusion cross sections. Applying this method to theoretical cross sections of single channel calculations, one obtains a system independent curve (the fusion function), that can be used as a benchmark to fusion data. The second conclusion was that none of the reduction methods available in the literature is able to provide a universal curve for total reaction cross sections. The reduced single channel cross sections keep a strong dependence of the atomic and mass numbers of the collision partners, except for systems in the same mass range. In the present work we pursue this problem further, applying the reduction methods to systems within a limited mass range. We show that, under these circumstances, the reduction of reaction data may be very useful.

  6. Undergraduate Measurements of Neutron Cross Sections

    NASA Astrophysics Data System (ADS)

    Hicks, S. F.; Vanhoy, J. R.; French, A. J.; Santonil, Z. C.; Crider, B. P.; Peters, E. E.; McEllistrem, M. T.; Prados-Estévez, F. M.; Ross, T. J.; Yates, S. W.

    Undergraduate students at the University of Dallas have investigated basic properties of nuclei through γ-ray and neutron spectroscopy following neutron scattering. The former has been used primarily for nuclear structure investigations, while the latter has been used to measure neutron scattering cross sections important for fission reactor applications. A series of (n,n') and (n,n'γ) measurements have been made on 54Fe and 56Fe to determine neutron cross sections for scattering to excited levels in these nuclei. The former provides the cross sections directly and the latter are used to deduce inelastic neutron scattering cross sections by measuring the γ-ray production cross sections to states not easily resolved in neutron spectroscopy. All measurements have been completed at the University of Kentucky Accelerator Laboratory using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. Students participate in accelerator operation, experimental setup, data acquisition, and data analyses. An overview of the research program and student contributions is presented.

  7. Absorption cross sections of stratospheric molecules

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.

    1974-01-01

    Two classes of molecular species must be considered in a calculation of photochemical rates in the stratosphere. The first class consists of molecular oxygen and ozone, while the second class contains the remainder of the minor constituents. If accurate values of the transmitted fluxes are required at large optical depths, the cross sections for molecular oxygen and ozone must be known to within a few per cent at least. On the other hand, the photochemical rates for the minor species are given simply by the relevant cross sections. A review of published cross sections is presented, giving attention to molecular oxygen, ozone, nitric oxide, nitrogen dioxide, nitrous oxide, nitric acid, ammonia, water vapor, hydrogen peroxide, carbon monoxide, carbon dioxide, and sulfur dioxide.

  8. The cross section for double Compton scattering

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1984-01-01

    Employing elementary methods in nonrelativistic quantum electrodynamics, the cross section for gamma sub 0 + e yields e + gamma + gamma is computed for arbitrary energy in the spectrum of the outgoing photons. The final result is given, differential in the energy of one of these photons, for the case where the incident photon is unpolarized and has energy E sub 0 much less than mc-squared, a polarization sum and angular integration being performed for the final-state photons. The cross section has a simple algebraic form resulting from contributions from the sum of squared direct and exchange amplitudes; interference terms from these amplitudes do not contribute to the angular-integrated cross section.

  9. Prospects for Precision Neutrino Cross Section Measurements

    SciTech Connect

    Harris, Deborah A.

    2016-01-28

    The need for precision cross section measurements is more urgent now than ever before, given the central role neutrino oscillation measurements play in the field of particle physics. The definition of precision is something worth considering, however. In order to build the best model for an oscillation experiment, cross section measurements should span a broad range of energies, neutrino interaction channels, and target nuclei. Precision might better be defined not in the final uncertainty associated with any one measurement but rather with the breadth of measurements that are available to constrain models. Current experience shows that models are better constrained by 10 measurements across different processes and energies with 10% uncertainties than by one measurement of one process on one nucleus with a 1% uncertainty. This article describes the current status of and future prospects for the field of precision cross section measurements considering the metric of how many processes, energies, and nuclei have been studied.

  10. Algorithmic analysis of quantum radar cross sections

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco; Venegas-Andraca, Salvador

    2015-05-01

    Sidelobe structures on classical radar cross section graphs are a consequence of discontinuities in the surface currents. In contrast, quantum radar theory states that sidelobe structures on quantum radar cross section graphs are due to quantum interference. Moreover, it is conjectured that quantum sidelobe structures may be used to detect targets oriented off the specular direction. Because of the high data bandwidth expected from quantum radar, it may be necessary to use sophisticated quantum signal analysis algorithms to determine the presence of stealth targets through the sidelobe structures. In this paper we introduce three potential quantum algorithmic techniques to compute classical and quantum radar cross sections. It is our purpose to develop a computer science-oriented tool for further physical analysis of quantum radar models as well as applications of quantum radar technology in various fields.

  11. Top differential cross section measurements (Tevatron)

    SciTech Connect

    Jung, Andreas W.

    2012-01-01

    Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb{sup -1} of data and measured the differential cross section as a function of the invariant mass of the t{bar t} system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio {kappa}/M{sub Pl} for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb{sup -1} of data to measure the differential cross section as a function of the transverse momentum of the top-quark. The measurement shows a good agreement to the next-to-leading order perturbative QCD prediction and various other standard model predictions.

  12. Improving activation cross section data with TALYS

    NASA Astrophysics Data System (ADS)

    Dzysiuk, Nataliia; Koning, Arjan

    2017-09-01

    Needs for accurate (n,x) activation cross sections for fusion technology have been considered with reference to the current status of the TENDL library. The current work is focused on improving activation cross section data for nuclear reactions relevant mainly for fusion and astrophysical needs. The fits have been performed with the TALYS-1.8 code by means of nuclear model parameter variation, mostly for the optical model and level densities, followed by comparison to recent experimental data taken from EXFOR and other evaluated nuclear databases. The updated cross section data are going to be adopted into the new version of TENDL. The improvements have been performed both for differential as well as integral data sets.

  13. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  14. New Parameterization of Neutron Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-01-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  15. Infrared absorption cross sections of alternative CFCs

    NASA Technical Reports Server (NTRS)

    Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

    1994-01-01

    Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

  16. Cross section for 246Cm subbarrier fission

    NASA Astrophysics Data System (ADS)

    Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

    2010-10-01

    The cross section for 246Cm fission induced by neutrons of energy in the range 0.1 eV-20 keV was measured by the neutron lead slowing-down spectrometer (LSDS-100) of the Institute for Nuclear Research (INR, Russian Academy of Sciences, Moscow). The parameters of the resonance area and of the fission width were evaluated for several low-lying s-wave neutron resonances. The parameters of the intermediate structure in the cross section for the subbarrier fusion of 246Cm nuclei were found. The results obtained in this way were compared with available experimental data and with recommended evaluated data.

  17. Optical Model and Cross Section Uncertainties

    SciTech Connect

    Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

    2009-10-05

    Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

  18. Multigroup cross section library for GFR2400

    NASA Astrophysics Data System (ADS)

    Čerba, Štefan; Vrban, Branislav; Lüley, Jakub; Haščík, Ján; Nečas, Vladimír

    2017-09-01

    In this paper the development and optimization of the SBJ_E71 multigroup cross section library for GFR2400 applications is discussed. A cross section processing scheme, merging Monte Carlo and deterministic codes, was developed. Several fine and coarse group structures and two weighting flux options were analysed through 18 benchmark experiments selected from the handbook of ICSBEP and based on performed similarity assessments. The performance of the collapsed version of the SBJ_E71 library was compared with MCNP5 CE ENDF/B VII.1 and the Korean KAFAX-E70 library. The comparison was made based on integral parameters of calculations performed on full core homogenous models.

  19. New Parameterization of Neutron Absorption Cross Sections

    NASA Astrophysics Data System (ADS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  20. Precise neutron inelastic cross section measurements

    SciTech Connect

    Negret, Alexandru

    2012-11-20

    The design of a new generation of nuclear reactors requires the development of a very precise neutron cross section database. Ongoing experiments performed at dedicated facilities aim to the measurement of such cross sections with an unprecedented uncertainty of the order of 5% or even smaller. We give an overview of such a facility: the Gamma Array for Inelastic Neutron Scattering (GAINS) installed at the GELINA neutron source of IRMM, Belgium. Some of the most challenging difficulties of the experimental approach are emphasized and recent results are shown.

  1. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1999-01-01

    Our prior nuclear absorption cross sections model is extended for light systems (A less than or equal to 4) where either both projectile and target are light particles or one is a light particle and the other is a medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium, and heavy systems, a very valuable input for radiation protection studies.

  2. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

  3. Total cross sections for +/-atom collisions

    NASA Astrophysics Data System (ADS)

    Gien, T. T.

    1987-03-01

    The total cross sections for electron and positron scatterings by lithium, sodium, and potassium in the intermediate energy range from 40 to 1000 eV are calculated using the modified Glauber and second Born approximations. A model potential approach is developed to enable an exact inclusion of the core-interaction effects. Within this approach, the positron cross sections are predicted to be somewhat smaller than those of electron scattering. Calculations have also been performed with the consideration of the inert-core and frozen-core assumption and the use of the Clementi wave function to represent the target electrons. Comparison to existing experimental data is made.

  4. Cross Sections From Scalar Field Theory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

    2008-01-01

    A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

  5. Reaction cross section of 22C

    NASA Astrophysics Data System (ADS)

    Togano, Yasuhiro; Samurai Collaboration

    2014-09-01

    Reaction cross section of 22C on a carbon target at an energy of 240 MeV/nucleon have been measured by using the transmission method. The most neutron-rich carbon isotopes 22C is a candidate of a two-neutron halo nucleus. Tanaka et al. [1] measured the reaction cross section of 22C on a hydrogen target at 40 MeV/nucleon. It is showed 22C to have a large matter radius of 5 . 9 +/- 0 . 9 fm, which is much larger than the ones of carbon isotopes with N <= 14 , suggesting 22C is the halo nucleus. This reported radius has a large uncertainty due to a lack of statistics. To deduce a more accurate matter radius of 22C, the measurement of reaction cross section with higher statistics at a higher beam energy are required. The experiment was performed by using the SAMURAI spectrometer at RIBF. The 22C beam at 240 MeV/nucleon was impinged on a carbon target, and the reaction product was identified by using SAMURAI spectrometer. In the present talk, the extracted reaction cross section and derived matter density distribution of 22C will be presented.

  6. Cotton fibre cross-section properties

    USDA-ARS?s Scientific Manuscript database

    From a structural perspective the cotton fibre is a singularly discrete, elongated plant cell with no junctions or inter-cellular boundaries. Its form in nature is essentially unadulterated from the field to the spinning mill where its cross-section properties, as for any textile fibre, are central ...

  7. Photoelectric absorption cross sections with variable abundances

    NASA Technical Reports Server (NTRS)

    Balucinska-Church, Monika; Mccammon, Dan

    1992-01-01

    Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

  8. Cross-sectional structural parameters from densitometry

    NASA Technical Reports Server (NTRS)

    Cleek, Tammy M.; Whalen, Robert T.

    2002-01-01

    Bone densitometry has previously been used to obtain cross-sectional properties of bone from a single X-ray projection across the bone width. Using three unique projections, we have extended the method to obtain the principal area moments of inertia and orientations of the principal axes at each scan cross-section along the length of the scan. Various aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of cross-sectional properties. Factors considered included X-ray photon energy, initial scan orientation, the angle spanned by the three scans (included angle), and I(min)/I(max) ratios. Principal moments of inertia were accurate to within +/-3.1% and principal angles were within +/-1 degrees of the expected value for phantoms scanned with included angles of 60 degrees and 90 degrees at the higher X-ray photon energy (140 kVp). Low standard deviations in the error (0.68-1.84%) also indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 degrees. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (I(min)/I(max)) values when various included angles are used make this technique viable for future in vivo studies.

  9. Cross-sectional structural parameters from densitometry

    NASA Technical Reports Server (NTRS)

    Cleek, Tammy M.; Whalen, Robert T.

    2002-01-01

    Bone densitometry has previously been used to obtain cross-sectional properties of bone from a single X-ray projection across the bone width. Using three unique projections, we have extended the method to obtain the principal area moments of inertia and orientations of the principal axes at each scan cross-section along the length of the scan. Various aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of cross-sectional properties. Factors considered included X-ray photon energy, initial scan orientation, the angle spanned by the three scans (included angle), and I(min)/I(max) ratios. Principal moments of inertia were accurate to within +/-3.1% and principal angles were within +/-1 degrees of the expected value for phantoms scanned with included angles of 60 degrees and 90 degrees at the higher X-ray photon energy (140 kVp). Low standard deviations in the error (0.68-1.84%) also indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 degrees. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (I(min)/I(max)) values when various included angles are used make this technique viable for future in vivo studies.

  10. Neutron capture cross section of Am241

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  11. Testing (Validating?) Cross Sections with ICSBEP Benchmarks

    SciTech Connect

    Kahler, Albert C. III

    2012-06-28

    We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

  12. Future experimental programme for neutrino cross sections

    NASA Astrophysics Data System (ADS)

    Bolognesi, Sara

    2017-09-01

    The neutrino-nucleus interaction modelling is crucial for a precise measurement of neutrino oscillations. The advantages and the drawbacks of the planned strategies to measure the neutrino-nucleus cross section with different detector technologies will be discussed. The present document summarizes a talk given on these topics at Neutrino 2016 conference.

  13. The Elusive p-air cross section

    NASA Astrophysics Data System (ADS)

    Block, M. M.

    2006-09-01

    For the $\\pbar p$ and $pp$ systems, we have used all of the extensive data of the Particle Data Group[K. Hagiwara {\\em et al.} (Particle Data Group), Phys. Rev. D 66, 010001 (2002).]. We then subject these data to a screening process, the ``Sieve'' algorithm[M. M. Block, physics/0506010.], in order to eliminate ``outliers'' that can skew a $\\chi^2$ fit. With the ``Sieve'' algorithm, a robust fit using a Lorentzian distribution is first made to all of the data to sieve out abnormally high $\\delchi$, the individual i$^{\\rm th}$ point's contribution to the total $\\chi^2$. The $\\chi^2$ fits are then made to the sieved data. We demonstrate that we cleanly discriminate between asymptotic $\\ln s$ and $\\ln^2s$ behavior of total hadronic cross sections when we require that these amplitudes {\\em also} describe, on average, low energy data dominated by resonances. We simultaneously fit real analytic amplitudes to the ``sieved'' high energy measurements of $\\bar p p$ and $pp$ total cross sections and $\\rho$-values for $\\sqrt s\\ge 6$ GeV, while requiring that their asymptotic fits smoothly join the the $\\sigma_{\\bar p p}$ and $\\sigma_{pp}$ total cross sections at $\\sqrt s=$4.0 GeV--again {\\em both} in magnitude and slope. Our results strongly favor a high energy $\\ln^2s$ fit, basically excluding a $\\ln s$ fit. Finally, we make a screened Glauber fit for the p-air cross section, using as input our precisely-determined $pp$ cross sections at cosmic ray energies.

  14. Sketching cross sections with a portable microcomputer

    SciTech Connect

    Kimberley, M.M.

    1985-02-01

    Computer applications have been carried to the field long ago by geophysicists and their dog houses. The advent of inexpensive battery-powered microcomputers promises to allow the field geologist to participate in this application. The field geologist may record data directly onto a computer-readable medium and calculate statistics or plot a cross section. A program for routine plotting of cross sections in the field has been developed and field-tested. The program proved to be useful to 30 computer-illiterate geologists on a 6-week mapping project in New Mexico. The program allows the user to control vertical exaggeration and displays the correct apparent dip along the chosen line of section. Cubic-spline interpolation is used to plot both topography and folded bedding planes. The program executes in Pascal on an Apple IIc in a few seconds.

  15. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.

    1985-01-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  16. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Astrophysics Data System (ADS)

    Townsend, L. W.; Wilson, J. W.

    1985-05-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  17. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  18. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  19. Rotational averaging of multiphoton absorption cross sections

    NASA Astrophysics Data System (ADS)

    Friese, Daniel H.; Beerepoot, Maarten T. P.; Ruud, Kenneth

    2014-11-01

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  20. Rotational averaging of multiphoton absorption cross sections.

    PubMed

    Friese, Daniel H; Beerepoot, Maarten T P; Ruud, Kenneth

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  1. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1997-01-01

    This paper presents a simple universal parameterization of total reaction cross sections for any system of colliding nuclei that is valid for the entire energy range from a few AMeV to a few AGeV. The universal picture presented here treats proton-nucleus collision as a special case of nucleus-nucleus collision, where the projectile has charge and mass number of one. The parameters are associated with the physics of the collision system. In general terms, Coulomb interaction modifies cross sections at lower energies, and the effects of Pauli blocking are important at higher energies. The agreement between the calculated and experimental data is better than all earlier published results.

  2. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  3. Extinction cross section of a dielectric strip

    NASA Astrophysics Data System (ADS)

    Dowerah, Subratananda; Chakrabarti, Aloknath

    1988-05-01

    The problem of scattering of a plane electromagnetic wave by a dielectric strip is formulated in terms of an uncoupled system of three-part Wiener-Hopf equations by using a set of approximate boundary conditions derived and utilized recently. The resulting Wiener-Hopf problems are solved approximately for sufficiently large values of the width of the strip by using Jones' method (1964). An analytical formula is derived for the excitation cross section of the strip under consideration from which numerical values are obtained in specific situations and the results are presented graphically. The radar cross section of the strip is also computed for several special circumstances and these are presented separately.

  4. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  5. Fusion cross sections and the new dynamics

    SciTech Connect

    Swiatecki, W.J.

    1981-05-01

    The prediction of the need for an extra push over the interaction barrier in order to make the heavier nuclei fuse is made the basis of a simple algebraic theory for the energy-dependence of the fusion cross-section. A comparison with recent experiments promises to provide a quantitative test of the New Dynamics (the theory of macroscopic nuclear shape evolutions based on the one-body dissipation concept).

  6. {sup 231}Pa photofission cross section

    SciTech Connect

    Soldatov, A.S.; Rudnikov, V.E.; Smirenkin, G.N.

    1995-12-01

    The measurements of the {sup 231}Pa yield and cross section photofission in the energy range 7-9 MeV are presented. These measurements are a continuation of similar measurements performed for the {gamma}-ray energy range 4.8-7 MeV. The entire collection of experimental data which combine the results obtained in the present work and in Ref. 1 was analyzed.

  7. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  8. Inclusive jet cross section at D0

    SciTech Connect

    Bhattacharjee, M.

    1996-09-01

    Preliminary measurement of the central ({vert_bar}{eta}{vert_bar} {<=} 0.5) inclusive jet cross sections for jet cone sizes of 1.0, 0.7, and 0.5 at D{null} based on the 1992-1993 (13.7 {ital pb}{sup -1}) and 1994-1995 (90 {ital pb}{sup -1}) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made.

  9. Inclusive jet cross section measurement at CDF

    SciTech Connect

    Pagliarone, C.

    1996-08-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  10. Active-beam cross-sectional modeling

    NASA Astrophysics Data System (ADS)

    Cesnik, Carlos E. S.; Ortega-Morales, Miguel

    2000-06-01

    A finite-element based analysis for modeling active composite beams with embedded anisotropic actuation is presented. It is derived from three-dimensional electroelasticity, where the original problem is reduced via the variational asymptotic method. The resulting cross-sectional analysis takes into consideration passive and active anisotropic and nonhomogeneous materials, and represents general (thin-walled, thick-walled, solid) cross-sectional geometries. The formulation requires neither the costly use of 3-D finite element discretization nor the loss of accuracy inherent to any simplified representation of the cross section. The developed formulation is numerically implemented in VABS-A, and several numerical and experimental tests cases are used to support validation of the proposed theory. Also, the effect of the presence of a core in originally hallow configurations is presented and counter-intuitive conclusions are discussed. The generality of the method and accuracy of the results increase confidence at the design stage that the active beam structure will perform as expected and, consequently, should lower costs from experimental tests and further adjustments.

  11. Quality Quantification of Evaluated Cross Section Covariances

    SciTech Connect

    Varet, S.; Dossantos-Uzarralde, P.

    2015-01-15

    Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the {sup 85}Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations.

  12. [Caesarean section: History, epidemiology, and ethics to diminish its incidence].

    PubMed

    Martínez-Salazar, Gerardo Jesús; Grimaldo-Valenzuela, Pedro Mario; Vázquez-Peña, Gloria Gabriela; Reyes-Segovia, Carlos; Torres-Luna, Gabriela; Escudero-Lourdes, Gabriela Virginia

    2015-01-01

    Cesarean section has become the most performed surgery and it has been enhanced with the use of antibiotics and improvement in surgical techniques. The aim of this systematic review is to describe and clarify some historical and ethical characteristics of this surgery, pointing out some aspects about its epidemiological behavior, becoming a topic that should be treated globally, giving priority to the prevention and identification of factors that may increase the incidence rates. Today, this "epidemic" reported rates higher than fifty percent, so it is considered a worldwide public health problem. Consequently, in Mexico strategies aimed at its reduction have been implemented. However, sociocultural, economic, medicolegal and biomedical factors are aspects that may difficult this goal. As we decrease the percentage of cesarean section in nulliparous patients, we diminish the number of iterative cesarean and its associated complications. This aim must be achieved through the adherence to the guidelines which promote interest in monitoring and delivery care in health institutions of our country.

  13. Averaging cross section data so we can fit it

    SciTech Connect

    Brown, D.

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  14. Preliminary cross section of Englebright Lake sediments

    USGS Publications Warehouse

    Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Overview -- The Upper Yuba River Studies Program is a CALFED-funded, multidisciplinary investigation of the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. Englebright Lake (Figure 1 on poster) is a narrow, 14-km-long reservoir located in the northern Sierra Nevada, northeast of Marysville, CA. The dam was completed in 1941 for the primary purpose of trapping sediment derived from mining operations in the Yuba River watershed. Possible management scenarios include lowering or removing Englebright Dam, which could cause the release of stored sediments and associated contaminants, such as mercury used extensively in 19th-century hydraulic gold mining. Transport of released sediment to downstream areas could increase existing problems including flooding and mercury bioaccumulation in sport fish. To characterize the extent, grain size, and chemistry of this sediment, a coring campaign was done in Englebright Lake in May and June 2002. More than twenty holes were drilled at 7 different locations along the longitudinal axis of the reservoir (Figure 4 on poster), recovering 6 complete sequences of post-reservoir deposition and progradation. Here, a longitudinal cross section of Englebright Lake is presented (Figure 5 on poster), including pre-dam and present-day topographic profiles, and sedimentologic sections for each coring site. This figure shows the deltaic form of the reservoir deposit, with a thick upper section consisting of sand and gravel overlying silt, a steep front, and a thinner lower section dominated by silt. The methodologies used to create the reservoir cross section are discussed in the lower part of this poster.

  15. Top Production Cross Sections at D0

    SciTech Connect

    Kvita, Jiri

    2009-07-01

    We report on measurements of the ttbar production cross section at a center-of-mass energy of 1.96 TeV at the D0 experiment during Run II of the Fermilab Tevatron collider. We use candidate events in lepton+jets and dilepton final states. In the most sensitive channel (lepton+jets channel), a neural network algorithm that uses lifetime information to identify b-quark jets is used to distinguish signal from background processes. We also present measurements of single top quark production at D0 using several multivariate techniques to separate signal from background.

  16. Critical behavior of cross sections at LHC

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    2016-07-01

    Recent experimental data on elastic scattering of high energy protons show that the critical regime has been reached at LHC energies. The approach to criticality is demonstrated by increase of the ratio of elastic to total cross sections from ISR to LHC energies. At LHC it reaches the value which can result in principal change of the character of proton interactions. The treatment of new physics of hollowed toroid-like hadrons requires usage of another branch of the unitarity condition. Its further fate is speculated and interpreted with the help of the unitarity condition in combination with present experimental data. The gedanken experiments to distinguish between different possibilities are proposed.

  17. Neutron absorption cross section of uranium-236

    SciTech Connect

    Macklin, R.L.; Alexander, C.W.

    1988-11-01

    U-236 neutron absorption was measured as a function of neutron time-of-flight from 20 eV to 1 MeV. The neutron flux was monitored with a /sup 6/Li glass scintillator. Average cross sections from 3 keV to 1 MeV were derived. Estimated uncertainties were less than 5% below 600 keV and increased to 9.5% at 1 MeV. Resonance parametrization from 20 eV to a few keV remains to be done. 17 refs., 5 figs., 3 tabs.

  18. Nuclear interaction cross sections for proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Jones, D. T. L.; Arendse, G. J.; Cowley, A. A.; Richter, W. A.; Lawrie, J. J.; Newman, R. T.; Pilcher, J. V.; Smit, F. D.; Steyn, G. F.; Koen, JW; Stander, JA

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  19. Pion production cross sections and associated parameters

    NASA Astrophysics Data System (ADS)

    Bradbury, J. N.

    Negative pions have been used for radiotherapy at the meson factories LAMPF (USA), SIN (Switzerland), and TRIUMF (Canada) and have been planned for use at new meson facilities under construction (USSR) and at proposed dedicated medical facilities. Providing therapeutically useful dose rates of pions requires a knowledge of the pion production cross sections as a function of primary proton energy (500 to 1000 MeV), pion energy (less than or equal to100 MeV), production angle, and target material. The current status of the data base in this area is presented including theoretical guidelines for extrapolation purposes. The target material and geometry, as well as the proton and pion beam parameters, will affect the electron (and muon) contamination in the beam which may have an important effect on both the LET characteristics of the dose and the dose distribution. In addition to cross-section data, channel characteristics such as length of pion trajectory, solid-angle acceptance, and momentum analysis will affect dose rate, distribution, and quality. Such considerations are briefly addressed in terms of existing facilities and proposed systems.

  20. Total cross sections for neutron scattering

    NASA Astrophysics Data System (ADS)

    Chinn, C. R.; Elster, Ch.; Thaler, R. M.; Weppner, S. P.

    1995-02-01

    Measurements of neutron total cross sections are both extensive and extremely accurate. Although they place a strong constraint on theoretically constructed models, there are relatively few comparisons of predictions with experiment. The total cross sections for neutron scattering from 16O and 40Ca are calculated as a function of energy from 50 to 700 MeV laboratory energy with a microscopic first-order optical potential derived within the framework of the Watson expansion. Although these results are aleady in qualitative agreement with the data, the inclusion of medium corrections to the propagator is essential to correctly predict the energy dependence given by the experiment. In the region between 100 and 200 MeV, where off-shell tρ calculations for both 16O and 40Ca overpredict the experiment, the modification due to the nuclear medium reduces the calculated values. Above 300 MeV these corrections are very small and depending on the employed nuclear mean field tend to compensate for the underprediction of the off-shell tρ results.

  1. Cross-Sectional and Longitudinal Associations between Egg Consumption and Metabolic Syndrome in Adults ≥ 40 Years Old: The Yangpyeong Cohort of the Korean Genome and Epidemiology Study (KoGES_Yangpyeong)

    PubMed Central

    Woo, Hye Won; Choi, Bo Youl; Kim, Mi Kyung

    2016-01-01

    Since the 1970s, the public has been advised to limit egg consumption even though there is little evidence of any harmful effect of eggs on blood cholesterol. The purpose of this cross-sectional and prospective study was to evaluate the potential association between egg consumption and metabolic syndrome (MetS) and MetS components in adults ≥ 40 years in KoGES_Yangpyeong. Yangpyeong is a rural area in South Korea. A total of 2,887 subjects (men 1,115, women 1,772) were recruited from 2005 to 2009, based on a physical examination and questionnaires administered using standardized protocol. After excluding subjects who had MetS at baseline, 1,663 subjects (675 men, 958 women) were followed for 3.20 years (range: 0.34–8.70). During the follow-up period, MetS occurred in 289 subjects. More than 3 eggs per week was significantly associated with decreased risk of MetS in both men (RR = 0.46, 95% CI, 0.26–0.82, P for trend = 0.1093) and women (RR = 0.54, 95% CI, 0.31–0.93, P for trend 0.0325) compared to non-users. There was a cross-sectional inverse relationship between egg consumption and abdominal obesity in men and women. Also, prospectively, higher egg consumption in men was associated with a decreased risk of high fasting blood glucose (RR = 0.39, 95% CI, 0.22–0.67, P for trend = 0.0042) and high triglycerides (RR = 0.42, 95% CI, 0.22–0.80, P for trend = 0.1080). In conclusion, our findings suggest that higher egg consumption may reduce the risk of MetS both in men and women, and the risk of high fasting blood glucose and high triglycerides in men. Current guidelines regarding egg consumption may need to be re-visited for healthy middle-aged and elderly people. PMID:26808174

  2. Accurate universal parameterization of absorption cross sections II--neutron absorption cross sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

    1997-01-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from approximately 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  3. Accurate universal parameterization of absorption cross sections II — neutron absorption cross sections

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from ˜ 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  4. Epidemiology of La Crosse Virus Emergence, Appalachia Region, United States

    PubMed Central

    Agusto, Folashade; Calabrese, Justin M.; Muturi, Ephantus J.; Fagan, William F.

    2016-01-01

    La Crosse encephalitis is a viral disease that has emerged in new locations across the Appalachian region of the United States. Conventional wisdom suggests that ongoing emergence of La Crosse virus (LACV) could stem from the invasive Asian tiger (Aedes albopictus) mosquito. Efforts to prove this, however, are complicated by the numerous transmission routes and species interactions involved in LACV dynamics. To analyze LACV transmission by Asian tiger mosquitoes, we constructed epidemiologic models. These models accurately predict empirical infection rates. They do not, however, support the hypothesis that Asian tiger mosquitoes are responsible for the recent emergence of LACV at new foci. Consequently, we conclude that other factors, including different invasive mosquitoes, changes in climate variables, or changes in wildlife densities, should be considered as alternative explanations for recent increases in La Crosse encephalitis. PMID:27767009

  5. Geophysical Fluid Flow Cell (GFFC) Cross Section

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This drawing shows a cross-section view of the test cell at the heart of the Geophysical Fluid Flow Cell (GFFC) that flew on two Spacelab missions. The middle and lower drawings depict the volume of the silicone oil layer that served as the atmosphere as the steel ball rotated and an electrostatic field pulled the oil inward to mimic gravity's effects during the experiments. The GFFC thus produced flow patterns that simulated conditions inside the atmospheres of Jupiter and the Sun and other stars. The principal investigator was John Hart of the University of Colorado at Boulder. It was managed by NASA's Marshall Space Flight Center (MSFC). An Acrobat PDF copy of this drawing is available at http://microgravity.nasa.gov/gallery. (Credit: NASA/Marshall Space Flight Center)

  6. Absolute photoneutron cross sections of Sm isotopes

    SciTech Connect

    Gheorghe, I.; Glodariu, T.; Utsunomiya, H.; Filipescu, D.; Nyhus, H.-T.; Renstrom, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  7. Neutrino Cross Sections at Supernova Energies

    NASA Astrophysics Data System (ADS)

    Scholberg, Kate

    2017-01-01

    Neutrinos with energies between a few and a few tens of MeV are relevant for a number of physics topics. Notably, this is the energy range corresponding to emission of neutrinos from supernovae. In addition, it is relevant for studies of solar, reactor and atmospheric neutrinos, as well as for physics using accelerator-produced neutrinos from pions or radioactive nuclei decaying at rest. Surprisingly, with the exception of interactions on electrons and protons, the interactions of neutrinos with matter in this energy range are quite poorly understood, both theoretically and experimentally. This talk will describe neutrino physics and astrophysics in the supernova-neutrino energy range, the state of knowledge of cross sections on relevant nuclei, and initiatives for experimental measurements.

  8. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  9. Top cross section measurement at CDF

    SciTech Connect

    Compostella, Gabriele; /INFN, CNAF /Padua U.

    2010-01-01

    This paper describes the latest measurements of the t{bar t} pair production cross section performed by the CDF Collaboration analyzing p{bar p} collisions at a center-of-mass energy of 1.96 TeV from Fermilab Tevatron, as presented at the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects. In order to test Standard Model predictions, several analysis methods are explored and all the top decay channels are considered, to better constrain the properties of the top quark and to search for possible sources of new physics affecting the pair production mechanism. Experimental results using an integrated luminosity up to 5.1 fb{sup -1} are presented.

  10. Angle-averaged Compton cross sections

    SciTech Connect

    Nickel, G.H.

    1983-01-01

    The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.

  11. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  12. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  13. Total and ionization cross sections of electron scattering by fluorocarbons

    NASA Astrophysics Data System (ADS)

    Antony, B. K.; Joshipura, K. N.; Mason, N. J.

    2005-02-01

    Electron impact total cross sections (50-2000 eV) and total ionization cross sections (threshold to 2000 eV) are calculated for typical plasma etching molecules CF4, C2F4, C2F6, C3F8 and CF3I and the CFx (x = 1-3) radicals. The total elastic and inelastic cross sections are determined in the spherical complex potential formalism. The sum of the two gives the total cross section and the total inelastic cross section is used to calculate the total ionization cross sections. The present total and ionization cross sections are found to be consistent with other theories and experimental measurements, where they exist. Our total cross section results for CFx (x = 1-3) radicals presented here are first estimates on these species.

  14. Electron Elastic-Scattering Cross-Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  15. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  16. Inclusive Neutrino Cross Section Measurements at MINERvA

    NASA Astrophysics Data System (ADS)

    Tice, Brian

    2012-10-01

    MINERvA part 4. The knowledge of inclusive neutrino cross sections is valuable for neutrino oscillation experiments. Determination of the A dependence of the cross section can help determine the role of nuclear effects in neutrino scattering, which is poorly known and difficult to model. Preliminary ratios of cross sections on carbon, iron and lead will be shown.

  17. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  18. Viscous Flow through Pipes of Various Cross-Sections

    ERIC Educational Resources Information Center

    Lekner, John

    2007-01-01

    An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

  19. Cross sectional study of osteoporosis among women.

    PubMed

    Agrawal, Tripti; Verma, A K

    2013-04-01

    Osteoporosis is a major public health problem, associated with substantial morbidity and socio-economic burden. An early detection can help in reducing the fracture rates and overall socio-economic burden. The present study was carried out to screen the bone status (osteopenia and osteoporosis) above the age of 35 yrs in the women. A community based cross sectional study was carried out in 158 women by calculating WHO T-scores utilizing calcaneal QUS as diagnostic tool. The prevalence of osteoporosis and osteopenia was found to be 13.3% ± 5.29% and 48.1% ± 7.79% respectively. Statistical association of prevalence of osteopenia and osteoporosis was found to be significant with age group; gravida status; attainment of menopause; body weight and physically active status of the women. The statistical association was not significant in relation to the rank status of their husband, as well as dietary pattern of the women but still it has to be substantiated by conducting larger community based trials in future. The present study found that there was statistically significant relationship between age group and the prevalence of osteopenia and osteoporosis. There was a negative correlation between age of the women and BMD. Besides age, gravida status and menopausal status have negative correlation with BMD while positive correlation with physically active lifestyle. The results were found to be non-significant in relation to rank status of husband and dietary pattern.

  20. Spectroscopy and Photoabsorption Cross Sections of FNO

    NASA Astrophysics Data System (ADS)

    Burley, J. D.; Miller, C. E.; Johnston, H. S.

    1993-04-01

    The spectroscopy and photoabsorption cross sections of nitrosyl fluoride are investigated in the spectral region 350-180 nm. Results for 350-250 nm are in good agreement with the initial measurements of Johnston and Bertin and later measurements from Solgadi and Flament and Huber et al. The spectrum is assigned to a series of vibrational progressions which arise from (0, 0, 0)″ and involve excitation of the ν' 1 mode. Excitations to ( n, 0, 0)' and ( n, 0, 1)' make up the bulk of the spectrum, with promotions to ( n, 1, 0)', ( n, 0, 2)', and ( n, 1, 2)' becoming dominant at higher energies. Analysis of the spectrum results in values of ν' 1 = 1096 cm -1, ν' 2 = 480cm -1 and ν' 3 = 349 cm -1 for the excited state FNO frequencies. The experimental basis for the assignment of ν' 1 and ν' 3 is distinctly stronger than that for ν' 2. Below 250 nm, a broad, featureless continuum absorption is observed, which rises in intensity from σ = 1.77 × 10 -20cm 2 at 245 nm to 5.24 × 10 -19cm 2 at 180 nm.

  1. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Başara, Işıl; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  2. Normalization of experimental electron cross sections.

    NASA Astrophysics Data System (ADS)

    Avdonina, N.; Felfli, Z.; Msezane, A. Z.

    1997-10-01

    Absolute experimental electron-impact differential cross sections (DCSs) can be obtained through an extrapolation of the relative generalized oscillator strength (GOS) values at some given impact energy E to zero momentum transfer squared K^2, the optical oscillator strength (OOS) [1]. We propose to normalize the relative experimental DCS data to the corresponding OOS value by extrapolating the GOS to K^2 = 0 without involving the nonphysical region. This is possible only by simultaneously increasing E and decreasing K^2 so that K^2 = 0 corresponds to E = ∞. Thus is avoided a divergence of fracd(GOS)d(K^2) at K^2 = 0 [2]. Another advantage of our method is that, over a wide range of small K^2 values the contribution of higher order terms of the Born series to the GOS function is negligible, contrary to the constant E case in which even order K^2 terms are non-Born [2]. Thus first Born approximation can be used to normalize relative experimental DCSs to the OOS. This method is applicable to both the excitation and ionization of atomic and molecular targets by electron impact. The latter case generalizes the method of ref. [3]. ^*Supported by AFOSR, NSF and DoE Div. of Chemical Sciences, OBES. ^1 E. N. Lassettre et al., J. Chem. Phys \\underline50, (1829) ^2 W. M. Huo, J. Chem. Phys \\underline71, 1593 (1979) ^3 A. Saenz, W Weyrich and P. Froelich, J. Phys. B \\underline29, 97 (1996)

  3. APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS

    DOEpatents

    Cranberg, L.

    1959-10-13

    An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

  4. Cross-sectional imaging in Crohn disease.

    PubMed

    Furukawa, Akira; Saotome, Takao; Yamasaki, Michio; Maeda, Kiyosumi; Nitta, Norihisa; Takahashi, Masashi; Tsujikawa, Tomoyuki; Fujiyama, Yoshihide; Murata, Kiyoshi; Sakamoto, Tsutomu

    2004-01-01

    The role of cross-sectional imaging in the diagnosis of Crohn disease has expanded with recent technologic advances in computed tomography (CT) and magnetic resonance (MR) imaging that allow rapid acquisition of high-resolution images of the intestines. To acquire images of diagnostic quality, administration of a fairly large amount of intraluminal contrast agent prior to examination and scanning with intravenous contrast material injection are necessary. Both CT and MR imaging are reported to have a sensitivity of over 95% for the detection of Crohn disease; however, they may not allow early diagnosis. Colonoscopy and conventional enteroclysis studies are indicated for patients with early-stage disease. At more advanced stages, CT and MR imaging can help identify and characterize pathologically altered bowel segments as well as extraluminal lesions (eg, fistulas, abscesses, fibrofatty proliferation, increased vascularity of the vasa recta, mesenteric lymphadenopathy). These modalities can also clearly depict inflammatory lesion activity and conditions that require elective gastrointestinal surgery, thereby aiding in treatment planning. In the clinical setting, CT is currently the imaging modality of choice at most institutions; however, it is expected that MR imaging will soon play a comparable role. CT or MR imaging should be included in a comprehensive evaluation of patients with Crohn disease, along with conventional imaging and clinical and laboratory tests.

  5. [Fast neutron cross section measurements]. Progress report

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  6. Graphs of the cross sections in the Alternate Monte Carlo Cross Section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Seamon, R.E.; Soran, P.D.

    1980-06-01

    Graphs of all neutron cross sections and photon production cross sections on the Alternate Monte Carlo Cross Section (AMCCS) library have been plotted along with local neutron heating numbers. The values of ..nu..-bar, the average number of neutrons per fission, are also plotted for appropriate isotopes.

  7. Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Soran, P.D.; Seamon, R.E.

    1980-05-01

    Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ..nu.., the average number of neutrons per fission, are also given.

  8. Crosstalk in rectangular cross-section heterogeneous multicore fiber

    NASA Astrophysics Data System (ADS)

    Egorova, Olga N.; Astapovich, Maxim S.; Semjonov, Sergey L.

    2016-09-01

    Using neighboring cores with different mode propagation constants (indexes) is a well-known way to reduce crosstalk in multicore fiber (MCF). However, in actual field-deployed fiber, random bends can cause a reduction in the difference between the mode indexes of neighboring cores, which consequently increases crosstalk. The level of crosstalk induced by bending in both rectangular cross-section and circular cross-section heterogeneous MCF with cores arranged in a line was investigated. The experimental results obtained indicate that in contrast to circular cross-section MCF, no bending-induced crosstalk occurs in rectangular cross-section MCF wound on the mandrel without special control of cross-section orientation. Thus, to eliminate undesirable bending-induced crosstalk in heterogeneous MCF a rectangular cross-section should be employed.

  9. Partial Photoneutron Cross Sections for 207,208Pb

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Iwamoto, C.; Akimune, H.; Yamagata, T.; Toyokawa, H.; Harada, H.; Kitatani, F.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.

    2014-05-01

    Using linearly-polarized laser-Compton scattering γ-rays, partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near neutron threshold by measuring anisotropies in photoneutron emission. Separately, total photoneutron cross sections were measured for 207,208Pb with a high-efficiency 4π neutron detector. The partial cross section measurement provides direct evidence for the presence of pygmy dipole resonance (PDR) in 207,208Pb in the vicinity of neutron threshold. The strength of PDR amounts to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to M1 cross sections less than 10% of the total photoneutron cross sections.

  10. Color dipole cross section and inelastic structure function

    NASA Astrophysics Data System (ADS)

    Jeong, Yu Seon; Kim, C. S.; Luu, Minh Vu; Reno, Mary Hall

    2014-11-01

    Instead of starting from a theoretically motivated form of the color dipole cross section in the dipole picture of deep inelastic scattering, we start with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section. Using the parametrizations of F 2(ξ = x or W 2 , Q 2) by Donnachie-Landshoff and Block et al., we find the dipole cross section from an approximate form of the presumed dipole cross section convoluted with the perturbative photon wave function for virtual photon splitting into a color dipole with massless quarks. The color dipole cross section determined this way reproduces the original structure function within about 10% for 0 .1 GeV2 ≤ Q 2 ≤10 GeV2. We discuss the dipole cross section at large and small dipole sizes and compare our results with other parametrizations.

  11. Total and partial photoneutron cross sections for Pb isotopes

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Daoutidis, I.; Iwamoto, C.; Akimune, H.; Okamoto, A.; Yamagata, T.; Kamata, M.; Itoh, O.; Toyokawa, H.; Lui, Y.-W.; Harada, H.; Kitatani, F.; Hilaire, S.; Koning, A. J.

    2012-07-01

    Using quasimonochromatic laser-Compton scattering γ rays, total photoneutron cross sections were measured for 206,207,208Pb near neutron threshold with a high-efficiency 4π neutron detector. Partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly polarized γ rays. The E1 strength dominates over the M1 strength in the neutron channel where E1 photoneutron cross sections show extra strength of the pygmy dipole resonance in 207,208Pb near the neutron threshold corresponding to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to an M1 cross section less than 10% of the total photoneutron cross section.

  12. Coupled multigroup cross sections for hydrogen interactions in plasmas

    NASA Astrophysics Data System (ADS)

    Wienke, B. R.; Morel, J. E.; Cayton, T. E.; Howell, R. B.

    1985-10-01

    Using analytical fits to the experimental cross sections for H 3 H 2, and H 2+ interactions in plasmas, developed by Gryzinski, Riviere, Jones, and Freeman, we obtain coupled multigroup cross sections and rate coefficients for hydrogen transport applications. Multigroup cross sections and rate coefficients, for specified energy group boundaries, plasma particle and temperature profiles, and cylindrical plasma confinement radius, are generated against a spatially dependent, local Maxwellian scattering background. Cross sections are formatted for direct use in production multigroup S n, Monte Carlo, or specific transport applications. Ten coupled hydrogen reactions are included and resulting cross sections for ionization, scattering, and production can be coupled or decoupled. Reactions treated include H, H 2 ionization by electrons and protons, H, H 2 charge exchange, and H 2, H 2+ dissociative mechanisms. We detail the formalism used to compute effective cross sections and rates and give practicle results for two fusion reactors.

  13. Cross-national epidemiology of panic disorder and panic attacks in the world mental health surveys.

    PubMed

    de Jonge, Peter; Roest, Annelieke M; Lim, Carmen C W; Florescu, Silvia E; Bromet, Evelyn J; Stein, Dan J; Harris, Meredith; Nakov, Vladimir; Caldas-de-Almeida, Jose Miguel; Levinson, Daphna; Al-Hamzawi, Ali O; Haro, Josep Maria; Viana, Maria Carmen; Borges, Guilherme; O'Neill, Siobhan; de Girolamo, Giovanni; Demyttenaere, Koen; Gureje, Oye; Iwata, Noboru; Lee, Sing; Hu, Chiyi; Karam, Aimee; Moskalewicz, Jacek; Kovess-Masfety, Viviane; Navarro-Mateu, Fernando; Browne, Mark Oakley; Piazza, Marina; Posada-Villa, José; Torres, Yolanda; Ten Have, Margreet L; Kessler, Ronald C; Scott, Kate M

    2016-12-01

    The scarcity of cross-national reports and the changes in Diagnostic and Statistical Manual version 5 (DSM-5) regarding panic disorder (PD) and panic attacks (PAs) call for new epidemiological data on PD and PAs and its subtypes in the general population. To present representative data about the cross-national epidemiology of PD and PAs in accordance with DSM-5 definitions. Nationally representative cross-sectional surveys using the World Health Organization Composite International Diagnostic Interview version 3.0. Respondents (n = 142,949) from 25 high, middle, and lower-middle income countries across the world aged 18 years or older. PD and presence of single and recurrent PAs. Lifetime prevalence of PAs was 13.2% (SE 0.1%). Among persons that ever had a PA, the majority had recurrent PAs (66.5%; SE 0.5%), while only 12.8% fulfilled DSM-5 criteria for PD. Recurrent PAs were associated with a subsequent onset of a variety of mental disorders (OR 2.0; 95% CI 1.8-2.2) and their course (OR 1.3; 95% CI 1.2-2.4) whereas single PAs were not (OR 1.1; 95% CI 0.9-1.3 and OR 0.7; 95% CI 0.6-0.8). Cross-national lifetime prevalence estimates were 1.7% (SE 0.0%) for PD with a median age of onset of 32 (IQR 20-47). Some 80.4% of persons with lifetime PD had a lifetime comorbid mental disorder. We extended previous epidemiological data to a cross-national context. The presence of recurrent PAs in particular is associated with subsequent onset and course of mental disorders beyond agoraphobia and PD, and might serve as a generic risk marker for psychopathology. © 2016 Wiley Periodicals, Inc.

  14. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  15. Left atrial vascularised thrombus diagnosed by transoesophageal cross sectional echocardiography.

    PubMed Central

    Taams, M A; Gussenhoven, E J; Lancée, C T

    1987-01-01

    This report describes a patient with a Björk-Shiley mitral valve prosthesis in whom transoesophageal cross sectional echocardiography revealed a large vascularised mass within the left atrial appendage with smoke-like opacification of blood flow in the left atrium. Transoesophageal cross sectional echocardiography gave a detailed image of the lesion which was unobtainable with precordial cross sectional echocardiography. Images Fig 1 Fig 2 PMID:3426904

  16. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  17. Analytical formulation of the quantum electromagnetic cross section

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2016-05-01

    It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.

  18. High E{sub T} jet cross sections at CDF

    SciTech Connect

    Flaugher, B.; CDF Collaboration

    1996-08-01

    The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

  19. Cross section dependence of event rates at neutrino telescopes.

    PubMed

    Hussain, S; Marfatia, D; McKay, D W; Seckel, D

    2006-10-20

    We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Scaling of the standard model cross sections leaves the rate of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon, and tau event rates in the IceCube detector confirm these results.

  20. Giant dipole resonance parameters with uncertainties from photonuclear cross sections

    NASA Astrophysics Data System (ADS)

    Plujko, V. A.; Capote, R.; Gorbachenko, O. M.

    2011-09-01

    Updated values and corresponding uncertainties of isovector giant dipole resonance (IVGDR or GDR) model parameters are presented that are obtained by the least-squares fitting of theoretical photoabsorption cross sections to experimental data. The theoretical photoabsorption cross section is taken as a sum of the components corresponding to excitation of the GDR and quasideuteron contribution to the experimental photoabsorption cross section. The present compilation covers experimental data as of January 2010.

  1. Capture cross sections from (p,d) reactions

    NASA Astrophysics Data System (ADS)

    Escher, J. E.; Burke, J. T.; Casperson, R. J.; Hughes, R. O.; Ota, S.; Scielzo, N. D.

    2017-09-01

    Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have been proposed to determine neutron capture cross sections for unstable isotopes. We consider an approach that aims at constraining statistical calculations of capture cross sections with data obtained from light-ion transfer reactions such as (p,d). We discuss the theoretical descriptions that have to be developed in order to extract meaningful cross section constraints from such data and show some benchmark results.

  2. Flow in tubes of non-circular cross-sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    Laminar, viscous, incompressible flow in tubes of noncircular cross sections is investigated. The specific aims of the investigation are (1) to look at the problems of both developing flow and fully developed flow, (2) to consider noncircular cross sections in a more systematic manner than has been done in the past, and (3) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent-shaped cross sections, and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the corresponding exact

  3. Proton-Air Cross Section and Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Ulrich, Ralf; Engel, Ralph; Müller, Steffen; Schüssler, Fabian; Unger, Michael

    2009-12-01

    Hadronic cross sections at ultra-high energy have a significant impact on the development of extensive air shower cascades. Therefore the interpretation of air shower data depends critically on hadronic interaction models that extrapolate the cross section from accelerator measurements to the highest cosmic ray energies. We discuss how extreme scenarios of cross section extrapolations can affect the interpretation of air shower data. We find that the theoretical uncertainty of the extrapolated proton-air cross section at ultra-high energies is much larger than suggested by the existing spread of available Monte Carlo model predictions. The impact on the depth of the shower maximum is demonstrated.

  4. Initial cross section for photodissociation of phosgene on Ag(111)

    NASA Astrophysics Data System (ADS)

    Zhou, X.-L.; White, J. M.

    1990-01-01

    The initial cross section for UV photodissociation of phosgene (Cl2CO) on Ag(111) at 100 K has been measured. With photon energies greater than 2.6 eV, submonolayer Cl2CO is readily photodissociated to surface Cl(a) and gas phase CO(g). The evolution of CO during photodissociation is readily monitored and used to calculate the initial photodissociation rate and cross section. The cross section is higher than the gas phase absorption cross section and is in the range of 10-18-10-19 cm2. It depends on the wavelength and the Cl2CO coverage.

  5. Inclusive Cross Section Production of J/ψ in LEP

    NASA Astrophysics Data System (ADS)

    Osati, T.; Abubakri, B.

    2017-02-01

    Cross section production is one of the observable quantities in the hadronic systems. Inclusive cross section production J/ψ may be calculated through the use of the fragmentation c → J/ψ. In this paper we calculate the inclusive cross section production J/ψ about the pole of Z 0 in the e + e ‑ annihilation, through the lowest order regim of perturbative of QCD ananlyticaly. The obtained results arrive an excellent agreement with the exprimental data to produce the inclusive cross section production c → J/ψ.

  6. Neutron capture cross section of {sup 102}Pd

    SciTech Connect

    Duncan, C.L.; Krane, K.S.

    2005-05-01

    The cross sections for radiative neutron capture by {sup 102}Pd have been deduced from a measurement of the {gamma} rays emitted by 17.0-d {sup 103}Pd. The thermal cross section has been determined to be {sigma}=1.82{+-}0.20 b, and the effective resonance integral is I=23{+-}4 b. We also report thermal and resonance capture cross sections for {sup 108}Pd and note possible inconsistencies with the presently accepted values of the {sup 110}Pd cross sections.

  7. Thermal Neutron Capture Cross Section of {sup 22}Ne

    SciTech Connect

    Belgya, T.; Uberseder, E.; Petrich, D.; Kaeppeler, F.

    2009-01-28

    The radiative thermal neutron capture cross section of the astrophysically important {sup 22}Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched {sup 22}Ne and CH{sub 4} were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7{+-}0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  8. Neutron-capture Cross Sections from Indirect Measurements

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  9. Cross-sectional study of malocclusion in Spanish children

    PubMed Central

    Montiel-Company, José M.; Bellot-Arcís, Carlos; Puertes-Fernández, Neus

    2014-01-01

    Objectives: This study was conducted to determine the orthodontic treatment need of the child population of the Valencia region of Spain, employing the DAI and the IOTN, to examine the relations between treatment need, socio-economic data and gender and to assess the diagnostic agreement between the two indices. Study Design: A cross-sectional descriptive study was conducted in a random representative sample of the schoolchild population of the Valencia region of Spain. The sample size was a total of 765 children aged 12 and 15 years at 39 schools. Results: The orthodontic treatment need assessed by the DAI was 21.7% at 12 years of age and 14.1% at 15 years. The orthodontic treatment need assessed by the IOTN DHC was 20.9% at 12 years of age and 12.7% at 15 years. The diagnostic agreement between the DAI and the modified IOTN was moderate, with Kappa scores of 0.426 at 12 years of age and 0.415 for the 15-year-old group. Conclusions: Approximately 20% of the children needed orthodontic treatment. Neither gender nor social class appeared to exert a significant influence on orthodontic treatment need. Key words:Orthodontics, epidemiology, children, malocclusion. PMID:23986013

  10. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    SciTech Connect

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  11. Section Builder: A finite element tool for analysis and design of composite beam cross-sections

    NASA Astrophysics Data System (ADS)

    Chakravarty, Uttam Kumar

    SectionBuilder is an innovative finite element based tool, developed for analysis and design of composite beam cross-sections. The tool can handle the cross-sections with parametric shapes and arbitrary configurations. It can also handle arbitrary lay-ups for predefined beam cross-section geometries in a consistent manner. The material properties for each layer of the cross-section can be defined on the basis of the design requirements. This tool is capable of dealing with multi-cell composite cross-sections with arbitrary lay-ups. It has also the benefit of handling the variation of thickness of skin and D-spars for beams such as rotor blades. A typical cross-section is considered as a collection of interconnected walls. Walls with arbitrary lay-ups based on predefined geometries and material properties are generated first. The complex composite beam cross-sections are developed by connecting the walls using various types of connectors. These connectors are compatible with the walls, i.e., the thickness of the layers of the walls must match with those of the connectors at the place of connection. Cross-sections are often reinforced by core material for constructing realistic rotor blade cross-sections. The tool has the ability to integrate core materials into the cross-sections. A mapped mesh is considered for meshing parametric shapes, walls and various connectors, whereas a free mesh is considered for meshing the core materials. A new algorithm based on the Delaunay refinement algorithm is developed for creating the best possible free mesh for core materials. After meshing the cross-section, the tool determines the sectional properties using finite element analysis. This tool computes sectional properties including stiffness matrix, compliance matrix, mass matrix, and principal axes. A visualization environment is integrated with the tool for visualizing the stress and strain distributions over the cross-section.

  12. Cross Sections for Inner-Shell Ionization by Electron Impact

    SciTech Connect

    Llovet, Xavier; Powell, Cedric J.; Salvat, Francesc; Jablonski, Aleksander

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  13. Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

    NASA Technical Reports Server (NTRS)

    Diana, L. M.; Chaplin, R. L.; Brooks, D. L.; Adams, J. T.; Reyna, L. K.

    1990-01-01

    An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

  14. Electron induced inelastic and ionization cross section for plasma modeling

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

    2016-09-01

    The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

  15. On the measurement of absorption cross sections of gaseous media

    SciTech Connect

    Gamalii, V.F.; Toptygin, D.D.

    1995-02-01

    A new technique for experimental determination of integral absorption cross sections of gaseous media by the method of modulation intracavity laser spectroscopy (MILS) is proposed. A formula relating the integral absorption cross section to the spectral position of radiation spectral condensation peaks in the absorption line wings is derived. 8 refs., 2 figs.

  16. Cross sections for scattering of electrons on BF_3

    NASA Astrophysics Data System (ADS)

    Radmilovic-Radjenovic, M.; Varambhia, H. N.; Vranic, M.; Tennyson, J.; Petrovic, Z. Lj.

    2008-07-01

    We calculate cross sections for elastic scattering and electronic excitation of BF_3 molecules by low energy electrons. The R-Matrix code Quantemol-N has been used for calculations. The cross sections indicate the presence of a shape resonance of symmetry B_1 (A_2'' in D_3h) at around 4.5 eV.

  17. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  18. First measurement of the charged current cross section at HERA

    NASA Astrophysics Data System (ADS)

    Ahmed, T.; Andreev, V.; Andrieu, B.; Appuhn, R.-D.; Arpagaus, M.; Babaev, A.; Bán, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Barth, M.; Bassler, U.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besançon, M.; Biddulph, P.; Bizot, J. C.; Blobel, V.; Borras, K.; Boudry, V.; Braemer, A.; Brasse, F.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Brune, C.; Büngener, L.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cussans, D. G.; Cvach, J.; Dagoret, S.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; Daum, K.; David, M.; Deffur, E.; Delcourt, B.; Del Buono, L.; De Roeck, A.; De Wolf, E.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Flauger, W.; Fleischer, M.; Flieser, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Genzel, H.; Gerhards, R.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E. M.; Hapke, M.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Höppner, M.; Huet, Ph.; Hufnagel, H.; Ibbotson, M.; Itterbeck, H.; Jabiol, M.-A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Janoth, J.; Jansen, T.; Jönsson, L.; Johannsen, K.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kant, D.; Kazarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Keuker, C.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Ko, W.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Krüner-Marquis, M.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurča, T.; Kurzhöfer, J.; Kuznik, B.; Lacour, D.; Lamarche, F.; Lander, R.; Landon, M. P. J.; Lange, W.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Leverenz, C.; Levonian, S.; Ley, Ch.; Lindner, A.; Lindström, G.; Linsel, F.; Lipinski, J.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Lüke, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Mercer, D.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Milstead, D.; Moreau, F.; Morris, J. V.; Müller, G.; Murín, P.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Nawrath, G.; Newman, P. R.; Newton, D.; Neyret, D.; Nguyen, H. K.; Niebergall, F.; Niebuhr, C.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg-Werther, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Panitch, A.; Pascaud, C.; Patel, G. D.; Peppel, E.; Perez, E.; Phillips, J. P.; Pichler, Ch.; Pitzl, D.; Pope, G.; Prell, S.; Prosi, R.; Rädel, G.; Raupach, F.; Reimer, P.; Reinshagen, S.; Ribarics, P.; Riech, V.; Riedlberger, J.; Riess, S.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rosenbauer, K.; Rostovtsev, A.; Royon, C.; Rüter, K.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Sahlmann, N.; Sanchez, E.; Sankey, D. P. C.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schöning, A.; Schröder, V.; Schulz, M.; Schwab, B.; Schwind, A.; Seehausen, U.; Sefkow, F.; Sell, R.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Shtarkov, L. N.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Stella, B.; Stephens, K.; Stier, J.; Stiewe, J.; Stösslein, U.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Tapprogge, S.; Taylor, R. E.; Tchernyshov, V.; Thiebaux, C.; Thompson, G.; Tichomirov, I.; Truöl, P.; Turnau, J.; Tutas, J.; Usik, A.; Valkar, S.; Valkarova, A.; Vallée, C.; Van Esch, P.; Van Mechelen, P.; Vartapetian, A.; Vazdik, Y.; Vecko, M.; Verrecchia, P.; Villet, G.; Wacker, K.; Wagener, A.; Walker, I. W.; Walther, A.; Weber, G.; Weber, M.; Weber, M.; Wegener, D.; Wegner, A.; Wellisch, H. P.; West, L. R.; Willard, S.; Winde, M.; Winter, G.-G.; Wolff, Th.; Wright, A. E.; Wünsch, E.; Wulff, N.; Yiou, T. P.; Žáček, J.; Zhang, Z.; Zimmer, M.; Zimmermann, W.; Zomer, F.; Zuber, K.; H1 Collaboration

    1994-03-01

    The cross section of the charged current process e-p → ve + hadrons is measured at HERA for transverse momenta of the hadron system larger than 25 GeV. The size of the cross section exhibits the W propagator.

  19. Benchmark Calculations of Electron-Impact Differential Cross Sections

    SciTech Connect

    Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T.

    2011-05-11

    The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

  20. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  1. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  2. Cross sections for electron collisions with nitric oxide

    SciTech Connect

    Itikawa, Yukikazu

    2016-09-15

    Cross section data are reviewed for electron collisions with nitric oxide. Collision processes considered are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, ionization, and dissociative electron attachment. After a survey of the literature (up to the end of 2015), recommended values of the cross section are determined, as far as possible.

  3. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  4. Temperature-dependent high resolution absorption cross sections of propane

    NASA Astrophysics Data System (ADS)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  5. Fission Cross Section Measurements of Actinides at LANSCE

    SciTech Connect

    F. Tovesson; A. B. Laptev; T. S. Hill

    2011-08-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the 235U standard. Recent measurements include the 233, 238U, 239-242Pu, and 243Am neutron-induced fission cross sections. In this paper preliminary results for fission cross sections of 243Am and 233U will be presented.

  6. On river cross-sectional change in the Niger Delta

    NASA Astrophysics Data System (ADS)

    Abam, T. K. S.; Omuso, W. O.

    2000-08-01

    A network of dominantly distributary river systems dissects the superficial deposits of the Niger Delta comprising alluvial sediments. Changes in river cross-sections are instigated mainly by bank failures, fluctuations in discharge, and bed degradation by fluvial processes. The relative importance of factors causing river cross-sectional change was ranked, based on a deterministic sensitivity technique involving partial differentiation of soil properties, flow characteristics, and geometrical parameters of the river channels. Analysis suggests that steep bank inclination and high flow velocity/discharge are the major causes of cross-sectional change, while interlocking of soil grains is the major erosion-restraining factor. Sensitivity coefficients were used further to generate susceptibility indices, indicating the vulnerability of channel cross-sections to change. Based on this, the risks of channel cross-sectional change were compared at different sites.

  7. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  8. Electron collision cross section sets of TMS and TEOS vapours

    NASA Astrophysics Data System (ADS)

    Kawaguchi, S.; Takahashi, K.; Satoh, K.; Itoh, H.

    2017-05-01

    Reliable and detailed sets of electron collision cross sections for tetramethylsilane [TMS, Si(CH3)4] and tetraethoxysilane [TEOS, Si(OC2H5)4] vapours are proposed. The cross section sets of TMS and TEOS vapours include 16 and 20 kinds of partial ionization cross sections, respectively. Electron transport coefficients, such as electron drift velocity, ionization coefficient, and longitudinal diffusion coefficient, in those vapours are calculated by Monte Carlo simulations using the proposed cross section sets, and the validity of the sets is confirmed by comparing the calculated values of those transport coefficients with measured data. Furthermore, the calculated values of the ionization coefficient in TEOS/O2 mixtures are compared with measured data to confirm the validity of the proposed cross section set.

  9. DPA Cross Section Library FermiDPA 1.0

    SciTech Connect

    Pronskikh, V. S.; Mokhov, N. V.

    2013-06-05

    DPA cross section library FermiDPA 1.0 based on the industry standard NRT model calculations is described. The library contains DPA cross sections for neutrons in the energy range 10$^{-5}$ eV 20 (150) MeV. Calculations used neutron-induced reaction cross sections from ENDFB-VII database of evaluated nuclear data. The NJOY99 nuclear data processing system's module HEATR was applied to calculate NRT model radiation damage cross sections. The FermiDPA 1.0 library is a database of 395 text files (for 395 known isotopes) with DPA cross sections. It is code-independent and can be implemented in any transport code.

  10. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  11. Analytical approximations for X-ray cross sections 3

    NASA Astrophysics Data System (ADS)

    Biggs, Frank; Lighthill, Ruth

    1988-08-01

    This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energies greater than or equal to 10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically.

  12. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Astrophysics Data System (ADS)

    Nicovich, J. M.; Wine, P. H.

    1988-03-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  13. Manpower Planning Models. 2. Cross Sectional Models

    DTIC Science & Technology

    1975-03-01

    numerous places including Debreu and Herstein [1953 ]. Section 8 is essentially taken from Branchflower [1970]. The reader interested in pursuing the...in a Graded Manpower System," Man. Sei. (Theory) Vol. 20, pp 76-84 (1973). ’ Debreu, G. and Herstein , I. N., "Non-negative Square Matrices

  14. Cross-section adjustment techniques for BWR adaptive simulation

    NASA Astrophysics Data System (ADS)

    Jessee, Matthew Anderson

    Computational capability has been developed to adjust multi-group neutron cross-sections to improve the fidelity of boiling water reactor (BWR) modeling and simulation. The method involves propagating multi-group neutron cross-section uncertainties through BWR computational models to evaluate uncertainties in key core attributes such as core k-effective, nodal power distributions, thermal margins, and in-core detector readings. Uncertainty-based inverse theory methods are then employed to adjust multi-group cross-sections to minimize the disagreement between BWR modeling predictions and measured plant data. For this work, measured plant data were virtually simulated in the form of perturbed 3-D nodal power distributions with discrepancies with predictions of the same order of magnitude as expected from plant data. Using the simulated plant data, multi-group cross-section adjustment reduces the error in core k-effective to less than 0.2% and the RMS error in nodal power to 4% (i.e. the noise level of the in-core instrumentation). To ensure that the adapted BWR model predictions are robust, Tikhonov regularization is utilized to control the magnitude of the cross-section adjustment. In contrast to few-group cross-section adjustment, which was the focus of previous research on BWR adaptive simulation, multigroup cross-section adjustment allows for future fuel cycle design optimization to include the determination of optimal fresh fuel assembly designs using the adjusted multi-group cross-sections. The major focus of this work is to efficiently propagate multi-group neutron cross-section uncertainty through BWR lattice physics calculations. Basic neutron cross-section uncertainties are provided in the form of multi-group cross-section covariance matrices. For energy groups in the resolved resonance energy range, the cross-section uncertainties are computed using an infinitely-dilute approximation of the neutron flux. In order to accurately account for spatial and

  15. Upper bound on the spin-flip cross section from unitarity, total cross section and the forward slope

    SciTech Connect

    Sakmar, I.A.

    1981-03-01

    For the spin 0--spin 1/2 particle scattering we give a method to construct an upper bound on the spin-flip cross section with the variational calculus using as constraints the total cross section, the forward slope and the full unitarity.

  16. Cross-Sectional Drawing Techniques And The Artist

    NASA Astrophysics Data System (ADS)

    Berry, William A.

    1980-07-01

    Although Democritus, a Greek pholosopher of the fifth century B.C. described the use of cross-sections in analyzing a solid form, this method was not extensively developed in art until the Renaissance. The earliest treatise documenting the integration of the cross-section and linear perspective is Piero della Francesca's De prospective pingendi (c. 1480), in which a drawing of the human head is mathematically conceived and plotted by means of cross-section contours. Piero's method anticipates contemporary biostereometric techniques and current theories of visual perception. Outside of theoretical treatises the complete cross-section rarely occurs in art, though certain pictorial elements such as the religious halo can be interpreted as cross-sections. The chan-ging representation of the halo in art of the Medieval, Renaissance and Baroque periods parallels the development of the artist's concepts and techniques for representing form and space. During the Renaissance and Baroque periods the widespread use of contour hatching, a drawing technique based on the cross-section, indicates that the cross-section concept has played a greater role in pictorial representation than has generally been recognized.

  17. Diffusion cross sections for potassium ? and ? levels in rare gases

    NASA Astrophysics Data System (ADS)

    Yahyaei-Moayyed, F.; Hickman, A. P.; Streater, A. D.

    1996-02-01

    We have used a light-induced drift (LID) experiment to determine ratios of cross sections for diffusion of potassium in the excited 0953-4075/29/3/011/img3, 0953-4075/29/3/011/img4 and the ground 0953-4075/29/3/011/img5 levels in five rare gases. The measured ratios are combined with the ground-state cross sections and statistically averaged excited cross sections, available from a previously reported light induced diffusive pulling experiment, to obtain the absolute cross sections for individual fine structure levels. We also report calculated cross sections based on available potential curves and a coupled-channel theory. Rough qualitative agreement is generally found between the absolute cross sections inferred from experiment and the theoretical values. The light-induced drift experiments, however, measure ratios of cross section differences that are highly sensitive to the potential curves. It is found that the available potential curves are not adequate for predicting these measured ratios.

  18. Cross Section Sensitivity and Propagated Errors in HZE Exposures

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

    2005-01-01

    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

  19. Electron impact ionization cross sections of beryllium-tungsten clusters*

    NASA Astrophysics Data System (ADS)

    Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

    2016-01-01

    We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

  20. Review of electron impact excitation cross sections for copper atom

    SciTech Connect

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  1. Fission cross sections in the intermediate energy region

    SciTech Connect

    Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. ); Carlson, A.D.; Wasson, O.A. ); Hill, N.W. )

    1991-01-01

    Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

  2. Infrared absorption cross sections of propane broadened by hydrogen

    NASA Astrophysics Data System (ADS)

    Wong, A.; Hargreaves, R. J.; Billinghurst, B.; Bernath, P. F.

    2017-09-01

    Fourier transform infrared absorption cross-sections of pure propane (C3H8) and propane broadened with H2 have been calculated from transmittance spectra recorded at temperatures from 292 K to 205 K. Transmittance spectra were recorded at the Canadian Light Source (CLS) Far-Infrared beamline, utilizing both the synchrotron source and the internal glowbar source. The absorption cross-sections have been calibrated to Pacific Northwest National Laboratory (PNNL) reference cross-sections of propane and can be used to interpret astronomical observations of giant planets such as Jupiter and Saturn as well as exoplanets.

  3. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  4. The 208Pb(n,γ) cross section

    NASA Astrophysics Data System (ADS)

    Beer, H.; Rochow, W.; Käppeler, F.; Rauscher, T.

    2003-05-01

    The Maxwellian average neutron capture (MAC) cross section of 208Pb has been reinvestigated. With the activation technique cross section measurements were performed at 25, 30, 52, 104, 149, and 215 keV. At 30 keV we succeeded to measure the direct p-wave capture part of the 208Pb capture cross section. The s-process at the termination of the synthesis has been analyzed. Independent calculations of s- and r-process yield a consistent decomposition for the Pb and Bi isotopic s- and r-contributions.

  5. Neutron total scattering cross sections of elemental antimony

    SciTech Connect

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-11-01

    Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V.

  6. Anemia in pregnancy in Malaysia: a cross-sectional survey.

    PubMed

    Haniff, Jamaiyah; Das, Anita; Onn, Lim Teck; Sun, Chen Won; Nordin, Noraihan Mohd; Rampal, Sanjay; Bahrin, Safiah; Ganeslingam, Muralitharan; Kularatnam, Kumar Iswaran K; Zaher, Zaki Morad Mohamad

    2007-01-01

    Anemia is the most prevalent nutritional deficiency during pregnancy. Except for a study conducted 10 years ago in Kelantan, Malaysia's available statistics are based on isolated small urban maternity hospital studies from the 1980s. There was therefore, a need for a large study at national level to estimate the magnitude of the problem in the country as well as to understand its epidemiology. This multi-center, cross-sectional study was conducted from February to March 2005, to assess the prevalence of anemia. Multistage stratified random sampling technique was used and 59 Ministry of Health (MOH) primary health care clinics were selected. Our final dataset consisted of 1,072 antenatal mothers from 56 clinics. The overall prevalence of anemia in this population was 35 % (SE 0.02) if the cut off level is 11 g/dL and 11 % (SE 0.03) if the cut-off level is 10 g/dL. The majority was of the mild type. The prevalence was higher in the teenage group, Indians followed by Malays and Chinese being the least, grandmultiparas, the third trimester and from urban residence. After multiple linear regression analysis, only gestational age remained significant. These findings are useful for our Maternal Health program planners and implementers to target and evaluate interventions. Work is in progress for outcomes and cost-effectiveness studies to best tackle this problem. In conclusion, the prevalence of anemia is 35% and mostly of the mild type and more prevalent in the Indian and Malays.

  7. A genetic algorithm to reduce stream channel cross section data

    USGS Publications Warehouse

    Berenbrock, C.

    2006-01-01

    A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

  8. Section B, general view of steel cross with new World ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Section B, general view of steel cross with new World Trade Center 7 in background, looking northwest. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  9. Photocopy of "sheet 6 of 8" showing cross section of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of "sheet 6 of 8" showing cross section of house, front elevation, fire finder stand, hip roof cap, and shiplap roof sheathing. - Badger Mountain Lookout, .125 mile northwest of Badger Mountain summit, East Wenatchee, Douglas County, WA

  10. Scaling Cross Sections for Ion-atom Impact Ionization

    SciTech Connect

    Igor D. Kaganovich; Edward Startsev; Ronald C. Davidson

    2003-06-06

    The values of ion-atom ionization cross sections are frequently needed for many applications that utilize the propagation of fast ions through matter. When experimental data and theoretical calculations are not available, approximate formulas are frequently used. This paper briefly summarizes the most important theoretical results and approaches to cross section calculations in order to place the discussion in historical perspective and offer a concise introduction to the topic. Based on experimental data and theoretical predictions, a new fit for ionization cross sections is proposed. The range of validity and accuracy of several frequently used approximations (classical trajectory, the Born approximation, and so forth) are discussed using, as examples, the ionization cross sections of hydrogen and helium atoms by various fully stripped ions.

  11. 12. CLOSEUP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET FROM LAKESHORE, SHOWING REMAINS OF SPILLWAY TIMBERS, LOOKING WEST - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  12. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  13. 20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  14. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  15. Cross section for the subthreshold fission of {sup 236}U

    SciTech Connect

    Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

    2008-08-15

    The cross section for {sup 236}U fission in the neutron-energy range E{sub n} = 0.001-20 keV was measured by using the INR RAS (Institute of Nuclear Research, Russian Academy of Sciences, Moscow) LSDS-100 neutron spectrometer of the lead slowing-down spectrometer type. The resonance fission areas of the resonances at 5.45 eV and 1.28 keV were found, and the fission widths of these resonances were evaluated. The cross section for the {sup 238}U(n, f) fission process was measured, and the threshold sensitivity of the LSDS-100 to small values of fission cross sections was estimated. The well-known intermediate structure in the cross section for the neutron-induced subbarrier fission of {sup 236}U was confirmed.

  16. Cross section for the subthreshold fission of 236U

    NASA Astrophysics Data System (ADS)

    Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

    2008-08-01

    The cross section for 236U fission in the neutron-energy range E n = 0.001 20 keV was measured by using the INR RAS (Institute of Nuclear Research, Russian Academy of Sciences, Moscow) LSDS-100 neutron spectrometer of the lead slowing-down spectrometer type. The resonance fission areas of the resonances at 5.45 eV and 1.28 keV were found, and the fission widths of these resonances were evaluated. The cross section for the 238U( n, f) fission process was measured, and the threshold sensitivity of the LSDS-100 to small values of fission cross sections was estimated. The well-known intermediate structure in the cross section for the neutron-induced subbarrier fission of 236U was confirmed.

  17. Superstructure Main Bridge, Cross Sections, Cantilever Structure Huey ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Superstructure - Main Bridge, Cross Sections, Cantilever Structure - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. Total cross sections for ultracold neutrons scattered from gases

    DOE PAGES

    Seestrom, Susan Joyce; Adamek, Evan R.; Barlow, Dave; ...

    2017-01-30

    Here, we have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n-butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He. The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to ourmore » previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.« less

  19. Total cross sections for ultracold neutrons scattered from gases

    NASA Astrophysics Data System (ADS)

    Seestrom, S. J.; Adamek, E. R.; Barlow, D.; Blatnik, M.; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Dees, E. B.; Fox, W.; Hoffbauer, M.; Hickerson, K. P.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Medina, J.; Morley, D. J.; Morris, C. L.; Pattie, R. W.; Ramsey, J.; Roberts, A.; Salvat, D. J.; Saunders, A.; Sharapov, E. I.; Sjue, S. K. L.; Slaughter, B. A.; Walstrom, P. L.; Wang, Z.; Wexler, J.; Womack, T. L.; Young, A. R.; Vanderwerp, J.; Zeck, B. A.

    2017-01-01

    We have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n -butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He . The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to our previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.

  20. 56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 1. SCE drawing no. 5206856 (no date; FERC no. 1933-46). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

  1. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  2. 4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  3. A new technique for dosimetry reaction cross-section evaluation

    SciTech Connect

    Badikov, S.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

  4. Neutral pion cross section measurement at K2K

    SciTech Connect

    Mariani, C.

    2007-12-21

    In this paper we report the measurement of the rate of the single {pi}{sup o} production in the K2K close detector. Neutral current single {pi}{sup o} production is measured in Oxygen, in the 1 KT detector. The cross section ratio relative to the total charged current cross section is found to be: 0.063{+-}0.001(stat.){+-}0.006(syst.) in good agreement with the Monte Carlo expectation. Inclusive charged current {pi}{sup o} production is measured in C{sub 8}H{sub 8}, in the SciBar detector, the cross section ratio for these processes relative to the charged current quasi elastic neutrino cross section is found to be 0.306{+-}0.023(stat.){+-}0.025(syst.) showing an excess of (39{+-}15)% (statistical and systematic error added in quadrature) with respect to the prediction of our reference Monte Carlo.

  5. Stellar (n ,γ ) cross sections of 23Na

    NASA Astrophysics Data System (ADS)

    Uberseder, E.; Heil, M.; Käppeler, F.; Lederer, C.; Mengoni, A.; Bisterzo, S.; Pignatari, M.; Wiescher, M.

    2017-02-01

    The cross section of the 23Na(n ,γ )24Na reaction was measured via the activation method at the Karlsruhe 3.7 MV Van de Graaff accelerator. NaCl samples were exposed to quasistellar neutron spectra at k T =5.1 and 25 keV produced via the 18O(p ,n )18F and 7Li(p ,n )7Be reactions, respectively. The derived capture cross sections <σ> kT =5 keV=9.1 ±0.3 mb and <σ> kT =25 keV=2.03 ±0.05 mb are significantly lower than reported in literature. These results were used to substantially revise the radiative width of the first 23Na resonance and to establish an improved set of Maxwellian average cross sections. The implications of the lower capture cross section for current models of s -process nucleosynthesis are discussed.

  6. Theory in Evaluation of Actinide Fission and Capture Cross Sections

    SciTech Connect

    Lynn, J. Eric

    2005-05-24

    We discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross sections. We consider especially the target 235U as an example. We emphasize the roles of intermediate structure in the fission cross section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near-barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross section. We compare such estimates with evaluated and experimental data for 235U.

  7. Photocopy of longitudinal, cross sections and roof plan of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of longitudinal, cross sections and roof plan of the C.B. & Q. R.R. roundhouse and locomotive shops. June 1980. - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

  8. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    NASA Astrophysics Data System (ADS)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  9. Inelastic cross sections for electron interactions in liquid water

    SciTech Connect

    Hamm, R.N.; Ritchie, R.H.; Turner, J.E.; Wright, H.A.

    1982-01-01

    The task was to develop a set of cross sections for electron inelastic processes in liquid water suitable for use in a Monte Carlo transport calculation. Results are plotted as inverse mean free paths vs electron energy. (DLC)

  10. Electron-Impact Total Ionization Cross Sections of Hydrocarbon Ions

    PubMed Central

    Irikura, Karl K.; Kim, Yong-Ki; Ali, M. A.

    2002-01-01

    The Binary-Encounter-Bethe (BEB) model for electron-impact total ionization cross sections has been applied to CH2+, CH3+, CH4+, C2H2+, C2H4+, C2H6+ and H3O+. The cross sections for the hydrocarbon ions are needed for modeling cool plasmas in fusion devices. No experimental data are available for direct comparison. Molecular constants to generate total ionization cross sections at arbitrary incident electron energies using the BEB formula are presented. A recent experimental result on the ionization of H3O+ is found to be almost 1/20 of the present theory at the cross section peak. PMID:27446718

  11. 28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  12. 15. Power plant elevations and cross sections, sheet 64 of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Power plant elevations and cross sections, sheet 64 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  13. Hadronic cross sections, elastic slope and physical bounds

    SciTech Connect

    Fagundes, D. A.; Menon, M. J.

    2013-03-25

    An almost model-independent parametrization for the ratio of the total hadronic cross section to elastic slope is discussed. Its applicability in studies of asymptotia and analyses of extensive air shower in cosmic-ray physics is also outlined.

  14. Absorption cross sections of the ClO dimer

    NASA Technical Reports Server (NTRS)

    Huder, K. J.; DeMore, W. B.

    1995-01-01

    The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

  15. Top Quark Pair Production Cross Section at the Tevatron

    SciTech Connect

    Peters, Reinhild Yvonne

    2015-09-25

    The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

  16. Gluon Saturation and the Total Proton-Air Cross Section

    NASA Astrophysics Data System (ADS)

    Carvalho, F.; Durães, F. O.; Szpigel, S.; Navarra, F. S.

    In this work we propose a simple model for the total proton-air cross section, which is an improvement of the minijet model with the inclusion of a window in the pT-spectrum associated to the saturation physics. Our approach introduces a natural cutoff for the perturbative calculations which modifies the energy behavior of this component. The saturated component is calculated with a dipole model. The results are compared with experimental cross sections measured in cosmic ray experiments.

  17. Relativistic corrections in K-shell ionization cross sections

    SciTech Connect

    Sheth, C.V.

    1984-03-01

    Relativistic effects on a modified version of Rutherford's scattering cross section are considered up to first-order in the Born approximation for relativistic velocities in the binary-encounter approximation (BEA). The predicted cross sections with protons as projectile are lower than the previous theoretical values at low energies and are seen to be in better agreement with measurements. An approximate relativistic correction factor which accounts for orbital electrons only is compared with exact Dirac corrections, within the BEA model.

  18. Enhancing the optical cross section of quantum antenna

    NASA Astrophysics Data System (ADS)

    Liu, Jingfeng; Zhou, Ming; Ying, Lei; Chen, Xuewen; Yu, Zongfu

    2017-01-01

    The classical radio-frequency antenna theory indicates that large cross sections can be realized through directional radiation. In this paper, a similar principle is applied in quantum systems, in which quantum antennas, constructed by a cluster of quantum two-level systems, explore the collective excitation of two-level systems to realize large directivity. Both the optical cross section and the coherent time can be dramatically enhanced in free space, far exceeding the case of a single two-level system.

  19. Experimental nuclear cross sections for spacecraft shield analysis

    NASA Technical Reports Server (NTRS)

    Peelle, R. W.

    1972-01-01

    Experiments have been performed to validate and to supplement the intranuclear cascade model as a method for estimating cross sections of importance to spacecraft shield design. The experimental situation is inconclusive particularly for neutron-producing reactions, but is relatively sound for reaction cross sections and for proton spectra at several hundred MeV at medium forward angles. Secondary photon contributions are imprecisely known.

  20. Asymptotic neutrino-nucleon cross section and saturation effects

    SciTech Connect

    Fiore, R.; Papa, A.; Jenkovszky, L.L.; Kotikov, A.V.; Paccanoni, F.

    2006-03-01

    In this paper we present a simple analytic expression for the (spin-averaged) neutrino-nucleon cross section for ultrahigh energies at twist-2, obtained as the asymptotic limit of our previous findings. This expression gives values for the cross section in remarkable numerical agreement with the previous numerical evaluation in the energy region relevant for forthcoming neutrino experiments. Moreover, we discuss the role and the relevance of saturation and recombination effects in our approach, in comparison with other recent suggestions.

  1. A Cross-Sectional Comparison of Army Advertising Attributes

    DTIC Science & Technology

    1990-11-01

    that identifies the needs and characteristics of individuals in the Armys’ prime market , as well as their exposure to Army advertising . One way the Army...U.S. Army Research Institute for the Behavioral and Social Sciences N Research Report 1578 A Cross-Sectional Comparison I of Army Advertising ...62785A 791 2105 H01 11. TITLE (Include Security Classification) A Cross-Sectional Comparison of Army Advertising Attributes 12. PERSONAL AUTHOR(S

  2. Differential cross sections for positron-xenon elastic scattering

    SciTech Connect

    Marler, J. P.; Surko, C. M.; McEachran, R. P.; Stauffer, A. D.

    2006-06-15

    Absolute measurements of differential cross sections for the elastic scattering of positrons from xenon are made at 2, 5 and 8 eV using a trap-based beam and the technique of measuring scattering cross sections in a strong magnetic field. Calculations are carried out using the relativistic Dirac equations with a static plus polarization potential. Generally good absolute agreement is found between experiment and theory.

  3. Thermal neutron capture cross sections of tellurium isotopes

    NASA Astrophysics Data System (ADS)

    Tomandl, I.; Honzátko, J.; von Egidy, T.; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklósi, L.; Révay, Zs.; Molnár, G. L.; Firestone, R. B.; Bondarenko, V.

    2003-12-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122 Te , 124 Te , 125 Te , 126 Te , 128 Te , and 130 Te are reported. These values are based on a combination of newly determined partial γ -ray cross sections obtained from experiments on targets contained natural Te and γ intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given.

  4. Photoproduction models for total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, Fernando; Garcia Canal, Carlos; Grau, Agnes; Pancheri, Giulia; Sciutto, Sergio

    2015-08-01

    A model for the total photoproduction cross section, based on the ansatz that resummation of infrared gluons limits the rise induced by QCD minijets in all the total cross-sections, is used to simulate extended air showers initiated by cosmic rays with the AIRES simulation program. The impact on common shower observables, especially those related with muon production, is analysed and compared with the corresponding results obtained with previous photoproduction models.

  5. On the interweaving of partial cross sections of different parity

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1979-01-01

    Partial cross sections of definite parity, calculated for electronic-rotational energy transfer in the F +H2 collision system, interweave with increasing total angular momentum J. An explanation, in terms of diabatic curve crossings induced by the centrifugal potential in the body-fixed coordinate system, predicts the interweaving to occur only in systems having half-integer J.

  6. Status of the Neutron Cross-Section Standards Database

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef; Carlson, Allan D.; Vonach, Herbert

    2005-05-01

    A new evaluation of the neutron cross-section standards is now underway. This evaluation has been supported by the Working Party on International Evaluation Cooperation (WPEC), the Cross Section Evaluation Working Group (CSEWG), and an International Atomic Energy Agency Coordinated Research Program (CRP). The CRP has had the dominant role in producing these evaluations. An important goal is to produce the standards needed for the upcoming new ENDF/B-VII library. Since most neutron cross-section measurements are made relative to neutron cross-section standards, the standards evaluation is of crucial importance. The standard reactions to be evaluated are: H(n,n), 3He(n,p), 6Li(n,t), 10B(n,α), 10B(n,α1γ), C(n,n), Au(n,γ), 235U(n,f), and 238U(n,f). These standards should receive international acceptance to ensure that all evaluation projects use the same set of standards. The last complete evaluation of the standards dates back almost 20 years. In the meantime quite a number of new and improved measurements have occurred for the cross-section standards. International efforts are presently underway to update the experimental database and to improve the evaluation process. Due to the need for high-energy standards, the energy range is being extended to 200 MeV for some of the cross-section standards.

  7. Photodissociation cross section of ClOOCl at 330 nm.

    PubMed

    Jin, Bing; Chen, I-Cheng; Huang, Wen-Tsung; Lien, Chien-Yu; Guchhait, Nikhil; Lin, Jim J

    2010-04-15

    The photolysis rate of ClOOCl is crucial in the catalytic destruction of polar stratospheric ozone. In this work, we determined the photodissociation cross section of ClOOCl at 330 nm with a molecular beam and with mass-resolved detection. The photodissociation cross section is the product of the absorption cross section and the dissociation quantum yield. We formed an effusive molecular beam of ClOOCl at a nozzle temperature of 200 or 250 K and determined its photodissociation probability by measuring the decrease of the ClOOCl intensity upon laser irradiation. By comparing with a reference molecule (Cl(2)), of which the absorption cross section and dissociation quantum yield are well-known, we determined the absolute photodissociation cross section of ClOOCl at 330 nm to be (2.31 +/- 0.11) x 10(-19) cm(2) at 200 K and (2.47 +/- 0.12) x 10(-19) cm(2) at 250 K. Impurity interference has been a well-recognized problem in conventional spectroscopic studies of ClOOCl; our mass-resolved measurement directly overcomes such a problem. This measurement of the ClOOCl photolysis cross section at 330 nm is particularly useful in constraining its atmospheric photolysis rate, which in the polar stratosphere peaks near this wavelength.

  8. Krypton charge exchange cross sections for Hall effect thruster models

    SciTech Connect

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2013-04-28

    Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr{sup +} + Kr and Kr{sup 2+} + Kr cross sections. The measurements of symmetric Kr{sup +} + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr{sup 2+} + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr{sup 2+} + Kr {yields} Kr{sup +} + Kr{sup +} reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A{sup 2} with an exception near 70-80 eV.

  9. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  10. Thermoelastic damping in microrings with circular cross-section

    NASA Astrophysics Data System (ADS)

    Li, Pu; Fang, Yuming; Zhang, Jianrun

    2016-01-01

    Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

  11. Coulomb and nuclear effects in breakup and reaction cross sections

    NASA Astrophysics Data System (ADS)

    Descouvemont, P.; Canto, L. F.; Hussein, M. S.

    2017-01-01

    We use a three-body continuum discretized coupled channel (CDCC) model to investigate Coulomb and nuclear effects in breakup and reaction cross sections. The breakup of the projectile is simulated by a finite number of square integrable wave functions. First we show that the scattering matrices can be split in a nuclear term and in a Coulomb term. This decomposition is based on the Lippmann-Schwinger equation and requires the scattering wave functions. We present two different methods to separate both effects. Then, we apply this separation to breakup and reaction cross sections of 7Li+208Pb . For breakup, we investigate various aspects, such as the role of the α +t continuum, the angular-momentum distribution, and the balance between Coulomb and nuclear effects. We show that there is a large ambiguity in defining the Coulomb and nuclear breakup cross sections, since both techniques, although providing the same total breakup cross sections, strongly differ for the individual components. We suggest a third method which could be efficiently used to address convergence problems at large angular momentum. For reaction cross sections, interference effects are smaller, and the nuclear contribution is dominant above the Coulomb barrier. We also draw attention to different definitions of the reaction cross section which exist in the literature and which may induce small, but significant, differences in the numerical values.

  12. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-07-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been reevaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding fifty years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  13. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-12-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  14. Studies of 54,56Fe Neutron Scattering Cross Sections

    NASA Astrophysics Data System (ADS)

    Hicks, S. F.; Vanhoy, J. R.; French, A. J.; Henderson, S. L.; Howard, T. J.; Pecha, R. L.; Santonil, Z. C.; Crider, B. P.; Liu, S.; McEllistrem, M. T.; Peters, E. E.; Prados-Estévez, F. M.; Ross, T. J.; Yates, S. W.

    2015-05-01

    Elastic and inelastic neutron scattering differential cross sections and γ-ray production cross sections have been measured on 54,56Fe at several incident energies in the fast neutron region between 1.5 and 4.7 MeV. All measurements were completed at the University of Kentucky Accelerator Laboratory (UKAL) using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. The facilities at UKAL allow the investigation of both elastic and inelastic scattering with nearly mono-energetic incident neutrons. Time-of-flight techniques were used to detect the scattered neutrons for the differential cross section measurements. The measured cross sections are important for fission reactor applications and also for testing global model calculations such as those found at ENDF, since describing both the elastic and inelastic scattering is important for determining the direct and compound components of the scattering mechanism. The γ-ray production cross sections are used to determine cross sections to unresolved levels in the neutron scattering experiments. Results from our measurements and comparisons to model calculations are presented.

  15. Electron cross-sections and transport in liquids and biomolecules

    NASA Astrophysics Data System (ADS)

    White, Ronald; Casey, M.; Cocks, D.; Konvalov, D.; Brunger, M. J.; Garcia, G.; Petrovic, Z.; McEachran, R.; Buckman, S. J.; de Urquijo, J.

    2016-09-01

    Modelling of electron induced processes in plasma medicine and radiation damage is reliant on accurate self-consistent sets of cross-sections for electrons in tissue. These cross-sections (and associated transport theory) must accurately account not only the electron-biomolecule interactions but also for the soft-condensed nature of tissue. In this presentation, we report on recent swarm experiments for electrons in gaseous water and tetrahydrofuran using the pulsed-Townsend experiment, and the associated development of self-consistent cross-section sets that arise from them. We also report on the necessary modifications to gas-phase cross-sections required to accurately treat electron transport in liquids. These modifications involve the treatment of coherent scattering and screening of the electron interaction potential as well as the development of a new transport theory to accommodate these cross-sections. The accuracy of the ab-initio cross-sections is highlighted through comparison of theory and experiment for electrons in liquid argon and xenon.

  16. Measured data used in the Watusi cross-section sets

    SciTech Connect

    Mustafa, M; Nethaway, D R

    1999-02-09

    In this document we list the experimental data that were used to make up the major cross- section sets that we use in the Watusi code to calculate the amount of detector activation in device tests. In order to use experimental data to make up a cross-section set, it is often necessary to extrapolate the cross sections down to either the threshold energy or to 0.01 keV, and to extrapolate up to 20 MeV. We then fit the data to a function so that we can get a smoothed set of interpolated values at up to 321 energy points. The combined data are then processed with the Hiroshima code into flux-weighted, group-averaged cross sections for use with the output from the different physics design codes. We typically use the standard 53 or 175 energy group structures. In a recent companion memo 1 we described the make up of all of the cross-section sets in detail, giving references to both the experimental data and the theoretical calculations that were used. The following sections have the experimental data, in the form of energy-cross section pairs, for the titanium, chromium, bromine, krypton, yttrium, zirconium, iodine, europium, lutetium, and bismuth sets. The other cross-section sets are not directly based on enough experimental data to warrant their listing here. Many of the reactions used in these sets are based on calculated cross sections. In making these calculations certain parameters are sometimes adjusted so that the calculated cross sections match experimental data. In some of these cases we have made a further normalization to give a closer agreement to selected experimental data, and such normalizations are noted in this document. In other cases no further normalization was made. In Table 1 we summarize the reactions for which we present the experimental data given in Tables 2-46. In Figs. 1-35 we show plots of the experimental data together with the actual excitation functions used in the cross-section sets. Some reactions in the current sets are based on

  17. 45. Cross Section through the Power House, from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Cross Section through the Power House, from Construction Drawing 2042-F-23, entitled General Arrangement of Power Plant, Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  18. 44. Cross section of the Blacksmith Shop from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Cross section of the Blacksmith Shop from Construction Drawing 2042-F-15, entitled Machine and Blacksmith Shop; Plan, Elevations, and Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  19. b Quark production cross sections and the b {minus} {bar b} correlated production cross section at CDF

    SciTech Connect

    Huffman, B.T.; CDF Collaboration

    1993-09-01

    Recent results on b quark and B meson production cross sections have been obtained at {radical}s = 1.8 TeV proton-antiproton collisions using the Collider Detector Facility (CDF) at Fermilab, using the exclusive decay modes B{sup {+-}} {yields}J/{Psi} K{sup {+-}} and B{sup 0} {yields} J/{Psi} K*. Another measurement made using data from the 1988--89 run on the correlated b + {bar b} cross section is also presented.

  20. Determining the partial photoionization cross-sections of ethyl radicals.

    PubMed

    FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

    2007-12-13

    Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

  1. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  2. Inclined Bodies of Various Cross Sections at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1958-01-01

    To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

  3. Improved empirical parameterization for projectile fragmentation cross sections

    NASA Astrophysics Data System (ADS)

    Mei, B.

    2017-03-01

    A new empirical parametrization is developed for calculating the fragment cross sections in projectile fragmentation reactions at high energies (>100 MeV/nucleon). The new parametrization, FRACS, consists of two main parts, i.e., the mass yield and the isobaric distribution, on the basis of previous parametrizations. The formalism for the mass yield is improved to describe the target and the projectile energy dependences observed in measured fragmentation cross sections. The parametrization of the isobaric distribution is also modified to reproduce recent experimental data. Furthermore, an additional term is proposed and first implemented in the FRACS parametrization to account for the evident odd-even staggering effect observed in many experimental cross sections. Comparisons with extensive cross sections measured in various fragmentation reactions reveal that FRACS is in much better agreement with experimental data and can reproduce measured cross sections in most cases within a factor of 1.84, which is a much smaller rms deviation as compared to that of the recent parametrization EPAX3.

  4. Determining (n,γ) cross sections using surrogate reactions

    NASA Astrophysics Data System (ADS)

    Scielzo, Nicholas; Escher, Jutta

    2009-10-01

    Direct measurements of neutron-reaction cross sections on unstable nuclei are extremely challenging due to the difficulties associated with radioactive targets and neutron beams. Indirect methods, such as the surrogate reaction method, are currently the only feasible way to determine many of the cross sections for radioactive nuclei that are of interest to nuclear astrophysics, nuclear energy, and other applications. We have used the surrogate reaction method to determine (n,γ) cross sections for ^153,155,157Gd nuclei at energies up to 3 MeV through inelastic proton scattering on stable targets. The STARS/LiBerACE silicon and germanium detector arrays were used to detect γ rays in coincidence with the scattered protons to determine γ-ray exit-channel probabilities. Techniques are being explored to extract reliable cross sections at energies for which the Weisskopf-Ewing limit of the Hauser-Feshbach theory is not applicable. This measurement will provide the first determination of the (n,γ) cross section for ^153Gd, an s-process branch-point nucleus with a half-life of 240 days. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  5. Modelling interaction cross sections for intermediate and low energy ions.

    PubMed

    Toburen, L H; Shinpaugh, J L; Justiniano, E L B

    2002-01-01

    When charged particles slow in tissue they undergo electron capture and loss processes that can have profound effects on subsequent interaction cross sections. Although a large amount of data exists for the interaction of bare charged particles with atoms and molecules, few experiments have been reported for these 'dressed' particles. Projectile electrons contribute to an impact-parameter-dependent screening of the projectile charge that precludes straightforward scaling of energy loss cross sections from those of bare charged particles. The objective of this work is to develop an analytical model for the energy-loss-dependent effects of screening on differential ionisation cross sections that can be used in track structure calculations for high LET ions. As a first step a model of differential ionisation cross sections for bare ions has been combined with a simple screening model to explore cross sections for intermediate and low energy dressed ions in collisions with atomic and molecular gas targets. The model is described briefly and preliminary results compared to measured ejected electron energy spectra.

  6. Theoretical Formalism To Estimate the Positron Scattering Cross Section.

    PubMed

    Singh, Suvam; Dutta, Sangita; Naghma, Rahla; Antony, Bobby

    2016-07-21

    A theoretical formalism is introduced in this article to calculate the total cross sections for positron scattering. This method incorporates positron-target interaction in the spherical complex optical potential formalism. The study of positron collision has been quite subtle until now. However, recently, it has emerged as an interesting area due to its role in atomic and molecular structure physics, astrophysics, and medicine. With the present method, the total cross sections for simple atoms C, N, and O and their diatomic molecules C2, N2, and O2 are obtained and compared with existing data. The total cross section obtained in the present work gives a more consistent shape and magnitude than existing theories. The characteristic dip below 10 eV is identified due to the positronium formation. The deviation of the present cross section with measurements at energies below 10 eV is attributed to the neglect of forward angle-discrimination effects in experiments, the inefficiency of additivity rule for molecules, empirical treatment of positronium formation, and the neglect of annihilation reactions. In spite of these deficiencies, the present results show consistent behavior and reasonable agreement with previous data, wherever available. Besides, this is the first computational model to report positron scattering cross sections over the energy range from 1 to 5000 eV.

  7. Progress on FP13 Total Cross Section Measurements Capability

    SciTech Connect

    Ullmann, John Leonard; Couture, Aaron Joseph; Koehler, Paul E.; Mocko, Michal; Mosby, Shea Morgan; Wender, Stephen Arthur

    2016-09-26

    An accurate knowledge of the neutron capture cross section is important for many applications. Experimental measurements are important since theoretical calculations of capture have been notoriously difficult, with the ratio of measured to calculated cross sections often a factor of 2 or more in the 10 keV to 1 MeV region. However, a direct measurement of capture cannot be made on many interesting radioactive nuclides because of their short half-life or backgrounds caused by their nuclear decay. On the other hand, neutron transmission measurements of the total cross section are feasible for a wide range of radioactive nuclides since the detectors are far from the sample, and often are less sensitive to decay radiation. The parameters extracted from a total cross section measurement, which include the average resonance spacing, the neutron strength function, and the average total radiation width, (Γγ), provide tight constraints on the calculation of the capture cross section, and when applied produce much more accurate results. These measurements can be made using the intense epithermal neutron flux at the Lujan Center on relatively small quantities of target material. It was the purpose of this project to investigate and develop the capability to make these measurements. A great deal of progress was made towards establishing this capability during 2016, including setting up the flight path and obtaining preliminary results, but more work remains to be done.

  8. 242Pu absolute neutron-capture cross section measurement

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.

    2017-09-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. During target fabrication, a small amount of 239Pu was added to the active target so that the absolute scale of the 242Pu(n,γ) cross section could be set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. The relative scale of the 242Pu(n,γ) cross section covers four orders of magnitude for incident neutron energies from thermal to ≈ 40 keV. The cross section reported in ENDF/B-VII.1 for the 242Pu(n,γ) En,R = 2.68 eV resonance was found to be 2.4% lower than the new absolute 242Pu(n,γ) cross section.

  9. Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Norbury, John W.

    2011-01-01

    It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

  10. Statistical Features of the Thermal Neutron Capture Cross Sections

    DOE PAGES

    Hussein, M. S.; Carlson, B. V.; Kerman, A. K.

    2016-02-01

    In this paper, we discuss the existence of huge thermal neutron capture cross sections in several nuclei. The values of the cross sections are several orders of magnitude bigger than expected at these very low energies. We lend support to the idea that this phenomenon is random in nature and is similar to what we have learned from the study of parity violation in the actinide region. The idea of statistical doorways is advanced as a unified concept in the delineation of large numbers in the nuclear world. The average number of maxima per unit mass, < nA > inmore » the capture cross section is calculated and related to the underlying cross section correlation function and found to be < nA > = 3/(π√2γA), where γA is a characteristic mass correlation width which designates the degree of remnant coherence in the system. Finally, we trace this coherence to nucleosynthesis which produced the nuclei whose neutron capture cross sections are considered here.« less

  11. Statistical Features of the Thermal Neutron Capture Cross Sections

    SciTech Connect

    Hussein, M. S.; Carlson, B. V.; Kerman, A. K.

    2016-02-01

    In this paper, we discuss the existence of huge thermal neutron capture cross sections in several nuclei. The values of the cross sections are several orders of magnitude bigger than expected at these very low energies. We lend support to the idea that this phenomenon is random in nature and is similar to what we have learned from the study of parity violation in the actinide region. The idea of statistical doorways is advanced as a unified concept in the delineation of large numbers in the nuclear world. The average number of maxima per unit mass, < nA > in the capture cross section is calculated and related to the underlying cross section correlation function and found to be < nA > = 3/(π√2γA), where γA is a characteristic mass correlation width which designates the degree of remnant coherence in the system. Finally, we trace this coherence to nucleosynthesis which produced the nuclei whose neutron capture cross sections are considered here.

  12. Electron Impact Ionization Cross Sections in Rb and Cs.

    NASA Astrophysics Data System (ADS)

    Reddish, T. J.; Lukomski, M.; Sutton, S.; Kedzierski, W.; McConkey, J. W.; Bartschat, K.; Bartlett, P. L.; Stelbovics, A. T.; Bray, I.

    2006-05-01

    We present a new atom trapping technique for determining absolute, total ionisation cross sections (TICS) out of an excited atom. The novel feature of this method is in utilizing Doppler cooling of neutral atoms to determine ionisation cross sections. This fluorescence-monitoring experiment, which is a variant of the `trap loss' technique, has enabled us to obtain the experimental electron impact ionisation cross sections out of the Cs 6^2P3/2 excited state between 7 - 400 eV. New CCC, R-Matrix with Pseudo-States (RMPS), and Born approximation single ionisation cross sections (SICS) are also presented for both the ground and excited states of Cs and Rb, and compared with the available experimental data. The comparison of the results reveals the importance of the autoionisation and multiple ionisation contributions to the TICS. The autoionisation contribution appears to be substantial for ionisation out of the Cs 6^2P and Rb 5^2P excited states; ˜ 3-4 larger than the direct ionisation contribution predicted by CCC at ˜ 30-50 eV. This surprising result shows the importance of multi-electron processes in determining the ionisation cross sections of heavy alkali atoms.

  13. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

    This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular application, the calculational bias of the library should be established by directly applicable critical experiments.

  14. Pion photoproduction cross section at large momentum transfer

    SciTech Connect

    Sjoegren, Johan

    2015-02-27

    The Real Compton Scattering experiment was performed in Hall A at the Thomas Jefferson National Accelerator Facility. It was designed to measure, for Compton scattering and π0-photoproduction, the differential cross section over a range of kinematic points and the polarisation transfer to the proton at a single kinematic point. The full range of the experiment in Mandelstam variables t and s was 1.6-6.46 GeV2 and 4.82-10.92 GeV2 respectively with beam energies of 2-6 GeV. The motivation for the experiment is to test the cross section and polarisation transfer predictions of perturbative QCD versus that of predictions from Generalised Parton Distribution models. This thesis will give an overview of the pertinent theory, experimental setup in Hall A and the extracting of the π0-photoproduction cross section.

  15. Radiative neutron capture cross section from 236U

    NASA Astrophysics Data System (ADS)

    Baramsai, B.; Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Roman, A. R.; Rusev, G.; Walker, C. L.; Couture, A.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Kawano, T.

    2017-08-01

    The 236U(n ,γ ) reaction cross section has been measured for the incident neutron energy range from 10 eV to 800 keV by using the Detector for Advanced Neutron Capture Experiments (DANCE) γ -ray calorimeter at the Los Alamos Neutron Science Center. The cross section was determined with the ratio method, which is a technique that uses the 235U(n ,f ) reaction as a reference. The results of the experiment are reported in the resolved and unresolved resonance energy regions. Individual neutron resonance parameters were obtained below 1 keV incident energy by using the R -matrix code sammy. The cross section in the unresolved resonance region is determined with improved experimental uncertainty. It agrees with both ENDF/B-VII.1 and JEFF-3.2 nuclear data libraries. The results above 10 keV agree better with the JEFF-3.2 library.

  16. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  17. Large cross sections for transitions with a small energy difference

    NASA Astrophysics Data System (ADS)

    McGuire, J. H.; Shakov, Kh. Kh.

    2009-05-01

    Cross sections for transitions between states with small differences in energy can be quite large. An example is the 1s-2p transition in atomic hydrogen caused by the impact of a fast charged particle [1] or a photon [3]. In such cases the actual cross section may become much larger than the simple geometric cross section. Such transitions are often difficult to observe in the laboratory. However, they can be evaluated numerically. This effect can be significant in analysis of astrophysical data, as pointed out by T. Nandi [2]. I discuss a few examples of calculations and give a physical explanation for this effect. [4pt] [1] J.H. McGuire, D. J. Land, J. G. Brennan and G. Basbas, Phys. Rev. A19, 2180 (1979).[0pt] [2] Kh.Kh. Shakov and J.H. McGuire, Phys. Rev. A67 033405 (2003). [0pt] [3] T. Nandi, private communication, 2008.

  18. Reaction cross sections of the deformed halo nucleus 31Ne

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Hagino, K.; Sagawa, H.

    2012-10-01

    Using the Glauber theory, we calculate reaction cross sections for the deformed halo nucleus 31Ne. To this end, we assume that the 31Ne nucleus takes the 30Ne+n structure. To take into account the rotational excitation of the core nucleus 30Ne, we employ the particle-rotor model (PRM). We compare the results to those in the adiabatic limit of PRM, that is, the Nilsson model, and show that the Nilsson model works reasonably well for the reaction cross sections of 31Ne. We also investigate the dependence of the reaction cross sections on the ground-state properties of 31Ne, such as the deformation parameter and the p-wave component in the ground-state wave function.

  19. Absorption Cross-Sections of Sodium Diatomic Molecules

    NASA Technical Reports Server (NTRS)

    Fong, Zeng-Shevan

    1985-01-01

    The absorption cross sections of sodium dimers were studied using a heat pipe over operating in the non-heat-pipe mode. Three wavelength regions were observed. They are in the red, the green-blue, and the near ultraviolet regions. The absorption cross section depends on the wavelength of the incident light. Representative peak values for the v"=0 progression in the red and green-blue regions are 2.59 A sup 2 (average value) and 11.77 A sup 2 (T sub ave=624 K). The value for the C greater than X transitions is several tenths A sup 2. The cross sections were measured from absorption spectra taken as a function of temperature.

  20. 63Ni (n ,γ ) cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Bredeweg, T. A.; Couture, A.; Göbel, K.; Heftrich, T.; Jandel, M.; Käppeler, F.; Lederer, C.; Kivel, N.; Korschinek, G.; Krtička, M.; O'Donnell, J. M.; Ostermöller, J.; Plag, R.; Reifarth, R.; Schumann, D.; Ullmann, J. L.; Wallner, A.

    2015-10-01

    The neutron capture cross section of the s -process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4 π BaF2 array DANCE. The (n ,γ ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s -process sensitivity of the new values was analyzed with the new network calculation tool NETZ.

  1. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Schulte, Elaine

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  2. Neutron scattering cross section measurements for Fe56

    DOE PAGES

    Ramirez, A. P. D.; Vanhoy, J. R.; Hicks, S. F.; ...

    2017-06-09

    Elastic and inelastic differential cross sections for neutron scattering from 56Fe have been measured for several incident energies from 1.30 to 7.96 MeV at the University of Kentucky Accelerator Laboratory. Scattered neutrons were detected using a C6D6 liquid scintillation detector using pulse-shape discrimination and time-of-flight techniques. The deduced cross sections have been compared with previously reported data, predictions from evaluation databases ENDF, JENDL, and JEFF, and theoretical calculations performed using different optical model potentials using the TALYS and EMPIRE nuclear reaction codes. The coupled-channel calculations based on the vibrational and soft-rotor models are found to describe the experimental (n,n0) andmore » (n,n1) cross sections well.« less

  3. Phenomenological barrier parameters for total reaction cross section

    NASA Astrophysics Data System (ADS)

    Phookan, C. K.; Kalita, K.

    2016-01-01

    A phenomenological formula for total reaction cross section is introduced for reactions induced by three types of projectiles. The formula is based on Wong's formula in which, the barrier parameters are calculated from the Bass, Aage Winther and the Akyuz Winther potentials. For the reactions studied, we find that a uniform correction of the barrier parameters can account for the total reaction cross section satisfactorily. An unusually large deviation of the barrier parameters is noticed for the reaction {}8{B} + {}^{58}{Ni}. Arguments are given that most likely the radius of the proton halo nucleus {}8{B} is not well accounted by the above potentials and hence, an increase in the effective radius of {}^8{B} is proposed. Analysis is also presented for the reaction {}^{11}{Li} + {}^{208}{Pb} by making the assumption that its reduced total reaction cross section lies on the same trajectory as that for other halo reactions.

  4. Lactiferous vessel detection from microscopic cross-sectional images

    NASA Astrophysics Data System (ADS)

    Jariyawatthananon, Jirapath; Cooharojananone, Nagul; Lipikorn, Rajalida

    2014-04-01

    This paper presents the methods to detect and segment lactiferous vessels or rubber latex vessels from gray scale microscopic cross-sectional images using polynomial curve-fitting with maximum and minimum stationary points. Polynomial curve-fitting is used to detect the location of lactiferous vessels from an image of a non-dyed cross-sectional slice which was taken by a digital camera through microscope lens. The lactiferous vessels are then segmented from an image using maximum and minimum stationary points with morphological closing operation. Two species of rubber trees of age between one to two years old are sampled namely, RRIM600 and RRIT251. Two data sets contain 30 microscopic cross-sectional images of one-year old rubber tree's stems from each species are used in the experiments and the results reveal that most of the lactiferous vessel areas can be segmented correctly.

  5. Total cross sections of beauty and charmed mesons on protons

    SciTech Connect

    Fridman, A.; Meshkov, S.

    1991-06-01

    Using a simple scaling law we predict the values of the total cross sections {sigma}(B{plus_minus}p), {sigma}B{sub d,s}{sup 0}, {sigma}({bar B}{sub d,s}{sup 0}P), {sigma}(D{sub d,s}{sup {plus_minus}}P), {sigma}(D{sup 0}p), {sigma}({bar D}{sup 0}p) from known total K{sub p} cross sections. We assume that mesons with the same light valence quark, q, and differing only by their heavy valence quark content, Q, have total cross sections on protons which scale as the inverse of the nth power of the reduced mass of the meson. We predict that {sigma}(Q{bar q})p > {sigma}({bar Q}q)p.

  6. Pion Total Cross Section in Nucleon - Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2009-01-01

    Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

  7. New Resonance Parameter Evaluation of Cl Neutron Cross Sections

    SciTech Connect

    Sayer, R.O.; Guber, K.H.; Leal, L.C.; Larson, N.M.

    2005-05-24

    Better measurements and evaluations are needed for many elements where the existing evaluations or the underlying nuclear cross-section data are not sufficiently accurate for reliable calculation of criticality safety margins. Deficiencies in the existing ENDF/B-VI data evaluation for Cl led to our resonance parameter evaluation of Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Our evaluation takes advantage of recent high-resolution capture and transmission measurements at the Oak Ridge Electron Linear Accelerator (ORELA) as well as older total cross-section measurements at Karlsruhe (KFK) to extend the resolved resonance energy range to 1.2 MeV with much more accurate representation of the data than previous evaluations.

  8. Accurate universal parameterization of absorption cross sections III - light systems

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Cucinotta, F. A.; Wilson, J. W.

    1999-09-01

    Our prior nuclear absorption cross sections model [R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, Nucl. Instr. and Meth. B 117 (1996) 347; R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 129 (1997) 11] is extended for light systems ( A ⩽ 4) where either both projectile and target are light particles or one is light particle and the other is medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium and heavy systems. As a result the extended model can reliably be used in all studies where there is a need for absorption cross sections.

  9. Cross section versus time delay and trapping probability

    NASA Astrophysics Data System (ADS)

    Luna-Acosta, G. A.; Fernández-Marín, A. A.; Méndez-Bermúdez, J. A.; Poli, Charles

    2016-07-01

    We study the behavior of the s-wave partial cross section σ (k), the Wigner-Smith time delay τ (k), and the trapping probability P (k) as function of the wave number k. The s-wave central square well is used for concreteness, simplicity, and to elucidate the controversy whether it shows true resonances. It is shown that, except for very sharp structures, the resonance part of the cross section, the trapping probability, and the time delay, reach their local maxima at different values of k. We show numerically that τ (k) > 0 at its local maxima, occurring just before the resonant part of the cross section reaches its local maxima. These results are discussed in the light of the standard definition of resonance.

  10. Electron impact double ionization cross sections of light elements

    NASA Astrophysics Data System (ADS)

    Talukder, M. R.; Haque, A. K. F.; Uddin, M. A.

    2009-06-01

    A simple user-friendly semiempirical model is proposed to calculate electron impact double ionization cross sections of He, Li, Li+, B+, C+, C3+, O, O2+, O3+, Ne, Ne+, Ne2+, Na, Mg, Al3+, S, and Arq+ (q=0-7) targets for the incident electron energies from threshold to 106 eV. The contributions in the total double ionization cross sections from the direct double ionization and inner-shell ionization processes are taken into account on the basis of experimental data considered. The results of the present analysis are compared with the available experimental data and theoretical calculations. The model is found successful for the description of experimental cross sections. Since, this model may be a prudent selection to meet the demand level in plasma modeling due to its simple inherent structure.

  11. Photoabsorption cross section of acetylene in the EUV region

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1985-01-01

    The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.

  12. Neutron scattering cross section measurements for 56Fe

    NASA Astrophysics Data System (ADS)

    Ramirez, A. P. D.; Vanhoy, J. R.; Hicks, S. F.; McEllistrem, M. T.; Peters, E. E.; Mukhopadhyay, S.; Harrison, T. D.; Howard, T. J.; Jackson, D. T.; Lenzen, P. D.; Nguyen, T. D.; Pecha, R. L.; Rice, B. G.; Thompson, B. K.; Yates, S. W.

    2017-06-01

    Elastic and inelastic differential cross sections for neutron scattering from 56Fe have been measured for several incident energies from 1.30 to 7.96 MeV at the University of Kentucky Accelerator Laboratory. Scattered neutrons were detected using a C6D6 liquid scintillation detector using pulse-shape discrimination and time-of-flight techniques. The deduced cross sections have been compared with previously reported data, predictions from evaluation databases ENDF, JENDL, and JEFF, and theoretical calculations performed using different optical model potentials using the talys and empire nuclear reaction codes. The coupled-channel calculations based on the vibrational and soft-rotor models are found to describe the experimental (n ,n0 ) and (n ,n1 ) cross sections well.

  13. Inelastic cross sections for positron scattering from atomic hydrogen

    SciTech Connect

    Weber, M.; Hofmann, A.; Raith, W.; Sperber, W.; Jacobsen, F.; Lynn, K.G.

    1994-12-31

    Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

  14. Neutron Capture Cross Section Calculations with the Statistical Model

    NASA Astrophysics Data System (ADS)

    Beard, Mary; Uberseder, Ethan; Wiescher, Michael

    2014-09-01

    Hauser-Feshbach (HF) cross sections are of enormous importance for a wide range of applications, from waste transmutation and nuclear technologies, to medical applications, and nuclear astrophysics. It is a well observed result that different nuclear input models sensitively affect HF cross section calculations. Less well-known however are the effects on calculations originating from model-specific implementation details (such as level density parameter, matching energy, backshift and giant dipole parameters), as well as effects from non-model aspects, such as experimental data truncation and transmission function energy binning. To investigate the effects or these various aspects, Maxwellian-averaged neutron capture cross sections have been calculated for approximately 340 nuclei. The relative effects of these model details will be discussed.

  15. Cross-sectional geometry of the dentary in bats.

    PubMed

    Dumont, Elizabeth R; Nicolay, Christopher W

    2006-01-01

    Bats exhibit remarkable diversity in dietary habits, with species specializing on insects, fruit, nectar, vertebrates and blood. Studies of larger mammals have shown that structural differences in dentary cross-sectional properties exist among species with different diets. Unfortunately, few of these studies have considered the role of phylogeny in shaping these apparent form-function associations. Here we ask whether a relationship exists between diet and dentary structure in bats when phylogenetic history is factored into the analysis. To answer this question, we compared results from phylogenetic generalized least squares (PGLS) and traditional (nonphylogenetic) regression analyses of dentary cross-sectional shape in frugivorous, nectarivorous, and insectivorous bats (253 individuals representing 72 species). Cross-sectional moments of inertia of the dentary between M(1) and M(2) were computed from bone densitometry scans of skeletal specimens. Traditional regressions of cross-sectional parameters against dentary length detected significant departures from isometry among frugivores. In contrast, PGLS analyses indicated that cross-sectional variables for each dietary group scaled with isometry. Thus, the allometric patterns illuminated by traditional statistics are linked to the phylogenetic structure of the sample. Identical patterns of significant differences in slopes and intercepts between frugivores and nectarivores emerged from both traditional and PGLS analyses. As predicted, the cross-sectional shape of the dentary in frugivores is consistent with increased resistance to torsion and bending, while that of nectarivores suggested a less resistant dentary. Although traditional and PGLS analyses yielded some similar results, the phylogenetic structure of a sample can drive apparent patterns of scaling and should be considered in comparative functional analyses.

  16. Stellar neutron capture cross sections of the Ba isotopes

    NASA Astrophysics Data System (ADS)

    Voss, F.; Wisshak, K.; Guber, K.; Käppeler, F.; Reffo, G.

    1994-11-01

    The neutron capture cross sections of 134Ba, 135Ba, 136Ba, and 137Ba were measured in the energy range from 5 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the 7Li (p,n)7 Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π barium fluoride detector. The cross section ratios were determined with an overall uncertainty of ~3%, an improvement by factors of 5 to 8 compared to existing data. Severe discrepancies were found with respect to previous results. As a new possibility in time of flight experiments, isomeric cross section ratios could be determined for 135Ba, 136Ba, and 137Ba. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT=10 keV and 100 keV. These stellar cross sections were used in an s-process analysis. For the s-only isotopes 134Ba and 136Ba the Ns<σ> ratio was determined to 0.875+/-0.025. Hence, a significant branching of the s-process path at 134Cs can be claimed for the first time, in contrast to predictions from the classical approach. This branching yields information on the s-process temperature, indicating values around T8=2. The new cross sections are also important for the interpretation of barium isotopic anomalies, which were recently discovered in SiC grains of carbonaceous chondrite meteorites. Together with the results from previous experiments on tellurium and samarium, a general improvement of the Ns<σ> systematics in the mass range A=120-150 is achieved. This yields a more reliable separation of s- and r-process contributions for comparison with stellar observations, but reveals a 20% discrepancy with respect to the solar barium abundance.

  17. Low energy cross sections for electron scattering from tetrafluoroallene

    NASA Astrophysics Data System (ADS)

    Gupta, Dhanoj; Choi, Heechol; Song, Mi-Young; Chakrabarti, Kalyan; Yoon, Jung-Sik

    2017-08-01

    We report elastic, total, excitation, differential and momentum-transfer cross sections for scattering of low-energy electrons by tetrafluoroallene (C3F4) using the close-coupling (CC) approximation in the R-matrix method with Quantemol-N. We have tested various target models initially to check for the convergence of the result and the final results are provided with the best target model. We have detected shape resonances of symmetry 2 E(2B1,2B2) at 3.08 eV and 3.71 eV with a close-coupling and static exchange models which is seen as a sharp feature in the elastic and momentum transfer cross sections. We also detected other resonances of symmetry 2 E at 11.26 eV and of symmetry 2A2 at 11.12 eV below the ionization threshold of the target respectively. The present elastic and total cross sections are compared with the elastic and total cross sections of allene (C3H4), propene (C3H6) and hexafluoropropene (C3F6) as there were no results available for C3F4. The effect of fluorination is clearly seen with the shape resonance for C3F4 getting slightly shifted to higher energies compared to allene. Finally, we also report the ionization cross section calculated using the Binary-Encounter Bethe (BEB) method. The present calculation is a maiden attempt to find cross sections for C3F4 molecule which could be useful for fluorocarbon plasma modeling.

  18. Cross sections for electron collisions with dimethyl ether

    NASA Astrophysics Data System (ADS)

    Sugohara, R. T.; Homem, M. G. P.; Iga, I.; de Souza, G. L. C.; Machado, L. E.; Ferraz, J. R.; dos Santos, A. S.; Brescansin, L. M.; Lucchese, R. R.; Lee, M. T.

    2013-08-01

    We report a joint theoretical-experimental investigation of electron collision with dimethyl ether (DME) in the low- and intermediate-energy ranges. Experimental absolute differential, integral, and momentum-transfer cross sections for elastic e--DME scattering are reported in the 100-1000 eV energy range. Our measurements were performed using a crossed electron-beam-molecular-beam geometry. The angular distribution of the scattered electrons was converted to absolute cross section using the relative flow technique. Theoretically, elastic differential, integral, and momentum-transfer cross sections, as well as the grand-total and total absorption cross sections for electron collision with DME are calculated in the 1-1000 eV energy range. A single-center-expansion technique combined with the Padé approximant method is used in our calculations. A comparison between the present experimental and theoretical data shows very good agreement. Moreover, comparison with theoretical and experimental data for e--ethanol (an isomer of DME) scattering shows interesting isomeric effects.

  19. Hadronic absorption cross sections of B{sub c}

    SciTech Connect

    Lodhi, M. A. K.; Akram, Faisal; Irfan, Shaheen

    2011-09-15

    The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

  20. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  1. Cross section expansion for direct neutron radiative capture

    SciTech Connect

    Baye, D.

    2004-07-01

    Cross sections for neutron radiative capture multiplied by the relative velocity can be expressed as a Taylor expansion in powers of the relative energy. The coefficients of this expansion are expressed in the potential model as integrals involving solutions of the radial Schroedinger equation and of its inhomogeneous energy derivatives calculated at zero energy. Similarities and differences with charged-particle capture are emphasized. The {sup 12}C(n,{gamma}){sup 13}C capture reaction is treated as an example. The coefficients of the Taylor expansion lead to simple parametrizations of the experimental partial cross sections for neutron capture to each {sup 13}C bound state.

  2. Total cross section of electron scattering by fluorocarbon molecules

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Ushiroda, S.; Kondo, Y.

    2008-12-01

    A compact linear electron transmission apparatus was used for the measurement of the total electron scattering cross section at 4-500 eV. Total cross sections of chlorofluorocarbon (CCl2F2), hydrochlorofluorocarbon (CHClF2), perfluoropropane (C3F8), perfluoro-n-pentane (C5F12), perfluoro-n-hexane (C6F14) and perfluoro-n-octane (C8F18) were obtained experimentally and compared with the values obtained from a theoretical calculation and semi-empirical model calculation.

  3. Measurements of multiphoton action cross sections for multiphoton microscopy

    PubMed Central

    Cheng, Li-Chung; Horton, Nicholas G.; Wang, Ke; Chen, Shean-Jen; Xu, Chris

    2014-01-01

    We report quantitative measurements of two-, three-, and four-photon excitation action cross sections of several commonly used fluorophores and fluorescent proteins at three different excitation wavelengths of 800 nm, 1300 nm, and 1680 nm. The measured cross section values are consistent with simple quantum mechanic estimations. These values indicate that the optimum repetition rate for deep tissue 3-photon microscopy is approximately 1 to 2 MHz. We further demonstrate that it is feasible to perform 4-photon fluorescence microscopy of GFP labeled microglia in mouse brain in vivo at 1700 nm. 4-photon excitation increases the accessibility of fluorophores at the long wavelength spectral window of 1700 nm. PMID:25360361

  4. Analysis and Simulation of Quantum Radar Cross Section

    NASA Astrophysics Data System (ADS)

    Liu, Kang; Xiao, Huai-Tie; Fan, Hong-Qi

    2014-03-01

    We derive a modified analytical expression of a quantum radar cross section (QRCS). Subsequently, we present a comparison between the QRCS and a classical radar cross section (RCS) and analyze the factors that can affect the intensity of the peak and side lobes. Simulation results on a flat rectangular plate demonstrate that QRCS has a similar structure to that of RCS. The analysis of side-lobe structure can benefit the design of quantum stealth platforms as well as the research on quantum radars.

  5. Cross section for {sup 246}Cm subbarrier fission

    SciTech Connect

    Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

    2010-10-15

    The cross section for {sup 246}Cm fission induced by neutrons of energy in the range 0.1 eV-20 keV was measured by the neutron lead slowing-down spectrometer (LSDS-100) of the Institute for Nuclear Research (INR, Russian Academy of Sciences, Moscow). The parameters of the resonance area and of the fission width were evaluated for several low-lying s-wave neutron resonances. The parameters of the intermediate structure in the cross section for the subbarrier fusion of {sup 246}Cm nuclei were found. The results obtained in this way were compared with available experimental data and with recommended evaluated data.

  6. New neutron cross section and fission yield data for SNManalysis

    SciTech Connect

    Firestone, R.B.; Molnar, G.L.; Revay, Zs.; Belgya, T.

    2003-05-28

    Neutron cross-section data are fundamental for the design ofnuclear interrogation systems, the maintenance of nuclear materials andwaste, and the understanding the consequences of nuclear catastrophe.Although a large body of nuclear data exists, it is often old,unreliable, or poorly determined. For several years we have collaborated,as part of an IAEA Coordinated Research Project, to precisely measure thepartial thermal neutron gamma ray cross sections for all elements fromhydrogen to uranium at the Budapest Reactor. These data will replace theunreliable tables of Lone et al [1], still widely in use, and will bepublished as an IAEA TECDOC.

  7. Inclusive charged particle cross sections in photoproduction at HERA

    NASA Astrophysics Data System (ADS)

    Abt, I.; Ahmed, T.; Andreev, V.; Aid, S.; Andrieu, B.; Appuhn, R.-D.; Arpagaus, M.; Babaev, A.; Bärwolff, H.; Bán, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besançon, M.; Biddulph, P.; Binder, E.; Bizot, J. C.; Blobel, V.; Borras, K.; Bosetti, P. C.; Boudry, V.; Bourdarios, C.; Braemer, A.; Brasse, F.; Braun, U.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Büngener, L.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Chyla, J.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cvach, J.; Dagoret, S.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; David, M.; Deffur, E.; Delcourt, B.; Del Buono, L.; Devel, M.; De Roeck, A.; Di Nezza, P.; Dingus, P.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Drescher, A.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Ebbinghaus, R.; Eberle, M.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellis, N. N.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Fensome, I. F.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Flauger, W.; Fleischer, M.; Flieser, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Fuhrmann, P.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Gennis, M.; Genzel, H.; Gerhards, R.; Godfrey, L.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, A.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E. M.; Hapke, M.; Harjes, J.; Haydar, R.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Höppner, M.; Huet, Ph.; Hufnagel, H.; Huot, N.; Ibbotson, M.; Itterbeck, H.; Jabiol, M.-A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Jansen, T.; Jönsson, L.; Johannsen, K.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kant, D.; Kazarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Keuker, C.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Ko, W.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurča, T.; Kurzhöfer, J.; Kuznik, B.; Lacour, D.; Lamarche, F.; Lander, R.; Landon, M. P. J.; Lange, W.; Langkau, R.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Leuschner, A.; Leverenz, C.; Levonian, S.; Lewin, D.; Ley, Ch.; Lindner, A.; Lindström, G.; Linsel, F.; Lipinski, J.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Lüke, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfiedl, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Mercer, D.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Monnier, E.; Moreau, F.; Moreels, J.; Morris, J. V.; Müller, K.; Murín, P.; Murray, S. A.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Newman, P. R.; Newton, D.; Neyret, D.; Nguyen, H. K.; Niebergall, F.; Niebuhr, C.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Orenstein, S.; Ould-Saada, F.; Pascaud, C.; Patel, G. D.; Peppel, E.; Peters, S.; Phillips, H. T.; Phillips, J. P.; Pichler, Ch.; Pilgram, W.; Pitzl, D.; Prell, S.; Prosi, R.; Rädel, G.; Raupach, F.; Rauschnabel, K.; Reimer, P.; Reinshagen, S.; Ribarics, P.; Riech, V.; Riedlberger, J.; Riess, S.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rosenbauer, K.; Rostovtsev, A.; Royon, C.; Rudowicz, M.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Sahlmann, N.; Sanchez, E.; Sankey, D. P. C.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmitz, W.; Schöning, A.; Schröder, V.; Schuhmann, E.; Schulz, M.; Schwab, B.; Schwind, A.; Scobel, W.; Seehausen, U.; Sell, R.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Shtarkov, L. N.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Soloviev, Y.; Spitzer, H.; Steenbock, M.; Steffen, P.; Steinberg, R.; Stella, B.; Stephens, K.; Stier, J.; Stösslein, U.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Taylor, R. E.; Tchernyshov, V.; Thiebaux, C.; Thompson, G.; Tichomirov, I.; Truöl, P.; Turnau, J.; Tutas, J.; Urban, L.; Usik, A.; Valkar, S.; Valkarova, A.; Vallée, C.; Van Esch, P.; Vartapetian, A.; Vazdik, Y.; Vecko, M.; Verrecchia, P.; Vick, R.; Villet, G.; Vogel, E.; Wacker, K.; Walker, I. W.; Walther, A.; Weber, G.; Wegener, D.; Wegner, A.; Wellisch, H. P.; West, L. R.; Willard, S.; Winde, M.; Winter, G.-G.; Wolff, Th.; Womersley, L. A.; Wright, A. E.; Wulff, N.; Yiou, T. P.; Žáček, J.; Zeitnitz, C.; Ziaeepour, H.; Zimmer, M.; Zimmermann, W.; Zomer, F.; H1 Collaboration

    1994-05-01

    Cross sections are presented for the inclusive production of charged particles measured in electron-proton collisions at low Q2 with the H1 detector at HERA. The transverse momentum distribution extends up to 8 GeV/ c. Its shape is found to be harder than that observed in overlinepp collisions at comparable centre-of-mass energies √S γp ≈ √S overlinepp ≈ 200 GeV, and also harder than in γp collisions at lower energies √ Sγp ≈ 18 GeV. Results from quantum chromodynamics (QCD) calculations agree with the measured transverse momentum and pseudorapidity cross sections.

  8. Charge Influence on Mini Black Hole's Cross Section

    NASA Astrophysics Data System (ADS)

    Caraça, R. S.; Malheiro, M.

    In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the fat brane approximation in the context of the ADD model. The maximum charge-mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light-ions but can be important for heavy-ions.

  9. Uncertainty quantification in fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  10. Uncertainty Quantification in Fission Cross Section Measurements at LANSCE

    SciTech Connect

    Tovesson, F.

    2015-01-15

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  11. Uncertainty quantification in fission cross section measurements at LANSCE

    DOE PAGES

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  12. The solar neutrino capture cross section for 81Br

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.

    1981-09-01

    The solar neutrino capture rate for the reaction 81Br + νe --> 81Kr + e- is calculated for the standard solar and weak interaction models. The results show that the capture cross section is dominated by the lowest Gamow-Teller transition to the metastable 1/2- (0.190 MeV) state in 81Kr. As the inverse electron capture rate for this transition has been measured recently, one can then argue that the cross section is well determined experimentally. Thus uncertainties in nuclear physics should not be an obstacle to the recently proposed 81Br radiochemical measurement of the 7Be solar neutrino flux. Present address.

  13. Inelastic cross sections from gamma-ray measurements

    SciTech Connect

    Nelson, Ronald Owen

    2010-12-06

    Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

  14. Evaluation of the /sup 238/U neutron total cross section

    SciTech Connect

    Smith, A.; Poenitz, W.P.; Howerton, R.J.

    1982-12-01

    Experimental energy-averaged neutron total cross sections of /sup 238/U were evaluated from 0.044 to 20.0 MeV using regorous numerical methods. The evaluated results are presented together with the associated uncertainties and correlation matrix. They indicate that this energy-averaged neutron total cross section is known to better than 1% over wide energy regions. There are somwewhat larger uncertainties at low energies (e.g., less than or equal to 0.2 MeV), near 8 MeV and above 15 MeV. The present evaluation is compard with values given in ENDF/B-V.

  15. Iterative cross section sequence graph for handwritten character segmentation.

    PubMed

    Dawoud, Amer

    2007-08-01

    The iterative cross section sequence graph (ICSSG) is an algorithm for handwritten character segmentation. It expands the cross section sequence graph concept by applying it iteratively at equally spaced thresholds. The iterative thresholding reduces the effect of information loss associated with image binarization. ICSSG preserves the characters' skeletal structure by preventing the interference of pixels that causes flooding of adjacent characters' segments. Improving the structural quality of the characters' skeleton facilitates better feature extraction and classification, which improves the overall performance of optical character recognition (OCR). Experimental results showed significant improvements in OCR recognition rates compared to other well-established segmentation algorithms.

  16. Absolute Photoionization Cross Sections of Two Cyclic Ketones: Cyclopentanone & Cyclohexanone.

    PubMed

    Price, Chelsea; Fathi, Yasmin; Meloni, Giovanni

    2017-02-23

    Absolute photoionization cross sections for cyclopentanone and cyclohexanone, as well as partial ionization cross sections for the dissociative ionized fragments, are presented in this investigation. Experiments are performed via a multiplexed photoionization mass spectrometer utilizing VUV synchrotron radiation supplied by the Advanced Light Source of Lawrence Berkeley National Laboratory. These results allow the quantification of these species that is relevant to investigate the kinetics and combustion reactions of potential biofuels. The CBS-QB3 calculated values for the adiabatic ionization energies agree well with the experimental values and the identification of possible dissociative fragments is discussed for both systems.

  17. Neutron removal cross section as a measure of neutron skin

    SciTech Connect

    Fang, D. Q.; Ma, Y. G.; Cai, X. Z.; Tian, W. D.; Wang, H. W.

    2010-04-15

    We study the relation between neutron removal cross section (sigma{sub -N}) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between sigma{sub -N} and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

  18. Cross-sectional imaging of the thyroid gland.

    PubMed

    Loevner, Laurie A; Kaplan, Summer L; Cunnane, Mary Elizabeth; Moonis, Gul

    2008-08-01

    Directed imaging is useful in assessing the thyroid gland. Nuclear scintigraphy reveals functional information about the thyroid gland, while cross-sectional imaging, including ultrasound, CT, and MR imaging provide important adjunctive anatomic information about the thyroid as well as about related structures in the neck, including the presence or absence of cervical and mediastinal lymphadenopathy, or extension of thyroid disease into adjacent soft tissues or the mediastinum. This article reviews the anatomy and physiology of the thyroid gland and addresses issues related to diseases affecting the thyroid gland, with an emphasis on neoplasms and the role of cross-sectional MR and CT imaging in the assessment of thyroid neoplasia.

  19. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1995-02-05

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos we have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. We give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  20. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1994-09-01

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos the authors have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. They give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  1. Partial photoneutron cross section measurements on 209Bi

    NASA Astrophysics Data System (ADS)

    Gheorghe, Ioana; Filipescu, Dan; Katayama, Seitaro; Utsunomiya, Hiroaki; Belyshev, Sergey; Stopani, Konstantin; Varlamov, Vladimir; Shima, Tatsushi; Lui, Yiu-Wing; Amano, Sho; Miyamoto, Shuji

    2017-09-01

    New data of total and partial (γ,xn) cross sections with x = 1-3 are proposed to be measured by direct neutron multiplicity sorting using Laser Compton scattering (LCS) gamma ray beams at the ELI-NP to solve long standing discrepancies between existing Lawrence Livermore National Laboratory (USA) and France Centre d'Etudes Nucleaires de Saclay photonuclear data. Pioneering experiments are currently performed at the NewSUBARU facility. We present here preliminary results on 209Bi(g,xn) cross section measurements.

  2. The 237U(n,f) Cross Section

    SciTech Connect

    Younes, W; Britt, H C; Wilhelmy, J B

    2003-03-03

    The purpose of this note is to combine existing information on the {sup 237}U(n,f) cross section to determine if some consistency can be obtained for the neutron induced fission excitation of {sup 237}U. The neutron induced fission cross section of the 6.8 day {sup 237}U was measured directly by McNally et al. in 1968 using the Pommard nuclear device test. At the same time critical assembly measurements were done at Los Alamos using the Flattop assembly. A previous measurement was also made at LASL in 1954 with two different neutron sources, each peaked near 200 keV. The results were 0.66 {+-} 0.10 b and 0.70 {+-} 0.07 b for the (n,f) cross section. More recently Younes and Britt have reanalyzed direct reaction charged particle data of Cramer and Britt that had determined the fission probability of the {sup 238}U compound nucleus as a function of nuclear excitation energy. They have combined fission probabilities with calculated neutron absorption cross sections, including corrections for the differences in angular momentum between the direct and neutron induced reactions. From this analysis they have extracted equivalent {sup 237}U(n,f) cross sections. The technique for extracting surrogate (n,f) cross sections from (t,pf) data has been demonstrated in a recent publication for the test case {sup 235}U(n,f). In addition to this experimental information, Lynn and Hayes have recently done a new theoretical study of the fission cross sections for a series of isotopes in this region. A summary plot of the data is shown in Fig. 1. Below 0.5 MeV the McNally, Cowan, and Younes-Britt results are in reasonable agreement. The average cross section in the Younes-Britt results, for En = 0.1 to 0.4 MeV, is 0.80 times the McNally values which is well within the errors of the McNally experiment. Above 0.5 MeV the McNally results diverge toward higher values. It should be noted that this divergence begins approximately at the {sup 237}Np threshold and that {sup 237}Np is the

  3. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L. F.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The ray is also drawn through the same leaf cross section with cell wall and air as the only optical mediums. The values of the reflection and transmission found from the ray tracing tests agree closely with the experimental results obtained using a Beckman Dk-2A Spectroreflector.

  4. Measurement of correlated b quark cross sections at CDF

    SciTech Connect

    Gerdes, D.; CDF Collaboration

    1994-09-01

    Using data collected during the 1992--93 collider run at Fermilab, CDF has made measurements of correlated b quark cross section where one b is detected from a muon from semileptonic decay and the second b is detected with secondary vertex techniques. We report on measurements of the cross section as a function of the momentum of the second b and as a function of the azimuthal separation of the two b quarks, for transverse momentum of the initial b quark greater than 15 GeV. Results are compared to QCD predictions.

  5. SU-E-I-43: Photoelectric Cross Section Revisited

    SciTech Connect

    Haga, A; Nakagawa, K; Kotoku, J; Horikawa, Y

    2015-06-15

    Purpose: The importance of the precision in photoelectric cross-section value increases for recent developed technology such as dual energy computed tomography, in which some reconstruction algorithms require the energy dependence of the photo-absorption in each material composition of human being. In this study, we revisited the photoelectric cross-section calculation by self-consistent relativistic Hartree-Fock (HF) atomic model and compared with that widely distributed as “XCOM database” in National Institute of Standards and Technology, which was evaluated with localdensity approximation for electron-exchange (Fock)z potential. Methods: The photoelectric cross section can be calculated with the electron wave functions in initial atomic state (bound electron) and final continuum state (photoelectron). These electron states were constructed based on the selfconsistent HF calculation, where the repulsive Coulomb potential from the electron charge distribution (Hartree term) and the electron exchange potential with full electromagnetic interaction (Fock term) were included for the electron-electron interaction. The photoelectric cross sections were evaluated for He (Z=2), Be (Z=4), C (Z=6), O (Z=8), and Ne (Z=10) in energy range of 10keV to 1MeV. The Result was compared with XCOM database. Results: The difference of the photoelectric cross section between the present calculation and XCOM database was 8% at a maximum (in 10keV for Be). The agreement tends to be better as the atomic number increases. The contribution from each atomic shell has a considerable discrepancy with XCOM database except for K-shell. However, because the photoelectric cross section arising from K-shell is dominant, the net photoelectric cross section was almost insensitive to the different handling in Fock potential. Conclusion: The photoelectric cross-section program has been developed based on the fully self-consistent relativistic HF atomic model. Due to small effect on the Fock

  6. Ozone absorption cross section measurements in the Wulf bands

    NASA Technical Reports Server (NTRS)

    Anderson, Stuart M.; Hupalo, Peter; Mauersberger, Konrad

    1993-01-01

    A tandem dual-beam spectrometer has been developed to determine ozone absorption cross sections for 13 selected wavelengths between 750 and 975 nm at room temperature. The increasingly pronounced structure in this region may interfere with atmospheric trace gas transitions that are useful for remote sensing and complicate the measurement of aerosols. Ozone concentrations were determined by absorption at the common HeNe laser transition near 632.8 nm using the absolute cross section reported previously. The overall accuracy of these room temperature measurements is generally better than 2 percent. A synoptic near-IR spectrum scaled to these measurements is employed for comparison with results of previous studies.

  7. Neutron capture cross section standards for BNL 325, Fourth Edition

    SciTech Connect

    Holden, N.E.

    1981-01-01

    This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: /sup 55/Mn(n,..gamma..), /sup 59/Co(n,..gamma..) and /sup 197/Au(n,..gamma..). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed.

  8. Propagation of sound waves in tubes of noncircular cross section

    NASA Technical Reports Server (NTRS)

    Richards, W. B.

    1986-01-01

    Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

  9. Knowledge of Ebola virus disease among a university population: A cross-sectional study.

    PubMed

    Salman, Muhammad; Shehzadi, Naureen; Hussain, Khalid; Saleem, Fahad; Khan, Muhammad Tanveer; Asif, Nauman; Yousaf, Maria; Rafique, Maham; Bedar, Rushda; Tariq, Sonia; AbuBakar, Usman; Syed Sulaiman, Syed Azhar

    2017-02-01

    This cross-sectional study aimed to evaluate the knowledge of a Pakistani university population (students and employees) regarding Ebola virus disease. A total of 2,200 individuals were approached and 1,647 were enrolled in the study. We observed that the vast majority of study participants (91.8%) had inadequate knowledge of Ebola virus disease (knowledge score ≤ 12). Our findings highlight the need to increase the knowledge of Ebola virus disease by using multidimensional approach involving awareness campaigns, print, electronic, and social media. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  10. 42. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. H-1 TO H-10 INCL., GRINDING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (NashVille, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  11. 35. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT 'B'.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  12. 34. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION B, BUILDINGS NO. E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  13. Radial Eigenmodes for a Toroidal Waveguide with Rectangular Cross Section

    SciTech Connect

    Rui Li

    2012-07-01

    In applying mode expansion to solve the CSR impedance for a section of toroidal vacuum chamber with rectangular cross section, we identify the eigenvalue problem for the radial eigenmodes which is different from that for cylindrical structures. In this paper, we present the general expressions of the radial eigenmodes, and discuss the properties of the eigenvalues on the basis of the Sturm-Liouville theory.

  14. 29. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  15. 30. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT 'B'.' From U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  16. JPRS Report, Science & Technology, China, Radar Cross Section Studies

    DTIC Science & Technology

    1991-04-03

    Section" (translated microstrip elements, to the extent possible. In order to by Ruan Yingzheng et al.), Electronics Industry Pub- reduce RCS further... ELECTRONICA SINICA] in Chinese Vol 18 No 6, difficult. There is a great deal of theoretical and experi- Nov 90 pp 92-96 [MS received Jul 89, revised Dec 89...34] 2. E. F. Knott, et al., "Radar Scattering Cross Section" [Excerpts] Abstract (Ruan Yingzheng, et al., editors), Electronics Industry Publishing

  17. Froissart bound on inelastic cross section without unknown constants

    NASA Astrophysics Data System (ADS)

    Martin, André; Roy, S. M.

    2015-04-01

    Assuming that axiomatic local field theory results hold for hadron scattering, André Martin and S. M. Roy recently obtained absolute bounds on the D wave below threshold for pion-pion scattering and thereby determined the scale of the logarithm in the Froissart bound on total cross sections in terms of pion mass only. Previously, Martin proved a rigorous upper bound on the inelastic cross-section σinel which is one-fourth of the corresponding upper bound on σtot, and Wu, Martin, Roy and Singh improved the bound by adding the constraint of a given σtot. Here we use unitarity and analyticity to determine, without any high-energy approximation, upper bounds on energy-averaged inelastic cross sections in terms of low-energy data in the crossed channel. These are Froissart-type bounds without any unknown coefficient or unknown scale factors and can be tested experimentally. Alternatively, their asymptotic forms, together with the Martin-Roy absolute bounds on pion-pion D waves below threshold, yield absolute bounds on energy-averaged inelastic cross sections. For example, for π0π0 scattering, defining σinel=σtot-(σπ0π0→π0π0+σπ0π0→π+π-) , we show that for c.m. energy √{s }→∞, σ¯ inel(s ,∞)≡s ∫s∞d s'σinel(s')/s'2≤(π /4 )(mπ)-2[ln (s /s1)+(1 /2 )ln ln (s /s1)+1 ]2 where 1 /s1=34 π √{2 π }mπ-2 . This bound is asymptotically one-fourth of the corresponding Martin-Roy bound on the total cross section, and the scale factor s1 is one-fourth of the scale factor in the total cross section bound. The average over the interval (s,2s) of the inelastic π0π0 cross section has a bound of the same form with 1 /s1 replaced by 1 /s2=2 /s1.

  18. 8. Photograph of a line drawing. SHEET 8, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photograph of a line drawing. SHEET 8, CROSS SECTION ON LINE EE; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  19. Evaluation of the neutron cross sections for Pu-240

    SciTech Connect

    Weston, L.W.; Arthur, E.D.

    1987-04-01

    The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for /sup 240/Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs.

  20. 11. Photograph of a line drawing. 'CROSS SECTION OF GAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photograph of a line drawing. 'CROSS SECTION OF GAS PRODUCER.' From George R. Cooper (Wilputte Corporation). 'Operating Overview of a Producer Gas Plant (12 Machines) at Kingsport, Tennessee.' Presented at the Fifth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity. University of Pittsburgh, August 2, 1978. - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN

  1. Differential cross section for the double photoionization of Mg

    NASA Astrophysics Data System (ADS)

    Abdel-Naby, Shahin A.; Pindzola, M. S.; Colgan, J.

    2015-01-01

    The time-dependent close-coupling (TDCC) method is used to calculate the energy and angle triple differential cross section for the double photoionization of Mg(3{{s}2}) at a photon energy of 55.49 eV to compare with recent converged close-coupling (CCC) calculations and in support of recent experiments at ELETTRA. Comparisons are made between the TDCC, CCC, and experimental results for equal energy sharing at scattering angles of 0{}^\\circ , 30{}^\\circ , and 60{}^\\circ , and for unequal energy sharing at 0{}^\\circ and 30{}^\\circ . Comparisons are made between the TDCC and CCC results for equal and unequal energy sharing at 90{}^\\circ . In addition, TDCC, CCC, and experimental results are compared for complex scattering amplitudes and the TDCC method is used to calculate single energy differential cross sections at photon energies of 30, 35, 40, 45, and 55.49 eV. Although there are scattering angles in the triple differential cross sections at 55.49 eV at which the TDCC, CCC, and experimental results are quite different, the overall agreement between the theories and experiment is reasonable for such small cross sections.

  2. 18. Cross section of Mormon Flat Dam completed. Structure on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Cross section of Mormon Flat Dam completed. Structure on parapet contains the operating mechanisms for the penstock gates. Power house is not yet under construction. Photographer unknown, 1926. Source: Salt River Project. - Mormon Flat Dam, On Salt River, Eastern Maricopa County, east of Phoenix, Phoenix, Maricopa County, AZ

  3. 23. Cross section of newly completed concrete channel and trestle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Cross section of newly completed concrete channel and trestle supported steel flume, 1919. Courtesy of the Mandeville Department of Special Collections, Central Library, University of California, San Diego. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  4. Photodissociation of Acetaldehyde and the Photoionization Cross Section of HCO

    NASA Astrophysics Data System (ADS)

    Shubert, V. Alvin; Pratt, Stephen T.

    2010-06-01

    Acetaldehyde was photodissociated with near UV laser light, and the methyl (CH_3) and formyl (HCO) radical fragments were photoionized with vacuum ultraviolet (VUV) light. The fragments were detected by using both time of flight mass spectrometry and velocity ion map imaging. With the former technique, simultaneous detection of both fragments provided the intensity of HCO+ relative to CH_3+ with I(HCO+)/I(CH_3+) ≈ 0.8. Because the absolute photoionization cross section of the CH_3 radical has been characterized (≈ 5 Mb) at the VUV energies of interest, the absolute photoionization cross section of HCO could be determined from the intensity ratio, yielding an HCO cross section of ≈ 4 Mb at 10.3 eV. However, because some of the HCO fragments could be formed with enough internal energy to undergo secondary dissociation, velocity ion map imaging was employed to determine the extent of any secondary dissociation that occurred. The translational energy distributions obtained for both the CH_3 and HCO fragments are nearly identical, indicating that no HCO fragments underwent secondary dissociation. A surprising result was the smaller photoionization cross section of HCO relative to CH_3. Comparison to the isoelectronic species of NO will be discussed and a potential explanation will be offered for this observation. This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences under contract No. DE-AC02-06CH11357.

  5. Experimental absolute cross section for photoionization of Xe^7+

    NASA Astrophysics Data System (ADS)

    Schippers, S.; Müller, A.; Esteves, D.; Habibi, M.; Aguilar, A.; Kilcoyne, A. L. D.

    2010-03-01

    Collision processes with highly charged xenon ions are of interest for UV-radiation generation in plasma discharges, for fusion research and for space craft propulsion. Here we report results for the photoionization of Xe^7+ ionsootnotetextS. Schippers et al., J. Phys.: Conf. Ser. (in print) which were measured at the photon-ion end station of ALS beamline 10.0.1. As compared with the only previous experimental studyootnotetextJ. M. Bizau et al., Phys. Rev. Lett. 84, 435 (2000) of this reaction, the present cross sections were obtained at higher energy resolution (50--80 meV vs. 200--500 meV) and on an absolute cross section scale. In the experimental photon energy range of 95--145 eV the cross section is dominated by resonances associated with 4d->5f excitation and subsequent autoionization. The most prominent feature in the measured spectrum is the 4d^9,s,f, resonance at 121.14±0.02 eV which reaches a peak cross section of 1.2 Gb at 50 meV photon energy spread. The experimental resonance strength of 160 Mb eV (corresponding to an absorption oscillator strength of 1.46) is in fair agreement with the theoretical result^2.

  6. Neutron capture cross section of {sup 241}Am

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-15

    The neutron capture cross section of {sup 241}Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for E{sub n}<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. {gamma}{sub n} neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553{+-}7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  7. Cross sections for low-energy inelastic H + Na collisions

    SciTech Connect

    Belyaev, A. K.; Barklem, P. S.; Dickinson, A. S.; Gadea, F. X.

    2010-03-15

    Full quantum-scattering calculations are reported for low-energy near-threshold inelastic collision cross sections for H+Na. The calculations include transitions between all levels up to and including the ionic state (ion-pair production) for collision energies from the threshold up to 10 eV. These results are important for astrophysical modeling of spectra in stellar atmospheres. Results for the 3s-3p excitation are carefully examined using three different quantum chemistry input data sets, and large differences are found near the threshold. The differences are found to be predominantly due to differences in the radial coupling rather than potentials and are also found not to relate to differences in couplings in a simple manner. In fact, of the three input couplings, the two that are most similar give the cross sections with the largest differences. The 3s-3p cross sections show orbiting resonances which have been seen in earlier studies, while Feshbach resonances associated with closed channels were also found to be present in the low-energy cross sections for some transitions.

  8. Extinction and backscatter cross sections of biological materials

    NASA Astrophysics Data System (ADS)

    Thomas, M. E.; Hahn, D. V.; Carr, A. K.; Limsui, D.; Carter, C. C.; Boggs, N. T.; Jackman, J.

    2008-04-01

    Aerosol backscatter and extinction cross-sections are required to model and evaluate the performance of both active and passive detection systems. A method has been developed that begins with laboratory measurements of thin films and suspensions of biological material to obtain the complex index refraction of the biological material from the UV to the LWIR. Using that result with particle size distribution and shape information as inputs to T-matrix or discrete dipole approximation (DDA) calculations yields the extinction cross-section and backscatter cross section as a function of wavelength. These are important inputs to the lidar equation. In a continuing effort to provide validated optical cross-sections, measurements have been made on a number of high purity biological species in the laboratory as well as measurements of material released at recent field tests. The resulting observed differences between laboratory and field measurements aid in distinguishing between intrinsic and extrinsic effects, which can affect the characteristic signatures of important biological aerosols. A variety of biological and test aerosols are examined, including Bacillus atrophaeus (BG), and Erwina, ovalbumin, silica and polystyrene.

  9. e+e- → charm cross sections via ISR

    NASA Astrophysics Data System (ADS)

    Pakhlova, Galina

    2010-06-01

    We discuss recent measurements of exclusive e+e- cross sections for charmed hadron final states near threshold performed by Belle and BABAR. The results are based on a study of events with initial-state-radiation photons in a large data sample collected with the Belle and BABAR detectors at the γ(4S) resonance and nearby continuum.

  10. Nerve cross-sectional area in extremes of age.

    PubMed

    Cartwright, Michael S; Mayans, David R; Gillson, Natalie A; Griffin, Leah P; Walker, Francis O

    2013-06-01

    Nerve cross-sectional area reference values have been reported for many nerves, but there have been few studies in pediatric and geriatric populations. This study was conducted to determine the influence of age on nerve cross-sectional area. Thirty-two children (3 months to 16 years) and 20 geriatric adults (67-92 years) without known neurologic conditions underwent bilateral ultrasound to measure the area of the following nerves: median at the wrist and forearm; ulnar at the wrist and elbow; radial in the spiral groove; sciatic in the distal thigh; fibular at the knee; tibial at the knee and ankle; and sural at the ankle. In general, nerve cross-sectional area increased with age. Nerve size correlated most closely with age, but a correlation was also seen with body mass index. Nerve cross-sectional area increases with age, which is important to note when using ultrasound to evaluate children and geriatric patients. Copyright © 2012 Wiley Periodicals, Inc.

  11. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.

    2015-06-01

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  12. A Cross-Sectional Study of Cognitive Variables.

    ERIC Educational Resources Information Center

    Grippin, Pauline; And Others

    Students in grades K, 1, 3, and 5 were administered the Rod and Frame Test (RFT), the Matching Familiar Figures (MFF) Test, and the Piagetian tasks of Discontinuous Quantity, Class Inclusion, Multiplication of Classes, and Multiplication of Relations. Cross-sectional trends were found in all tasks with older children being less impulsive, more…

  13. Applications of cross sections for electron-molecule collision processes

    SciTech Connect

    Cartwright, D.C.

    1985-01-01

    The role of electron-molecule collision cross sections is discussed for the study of the ionospheric and auroral processes in planetary atmospheres and of discharge-pumped lasers. These two areas emphasize the importance of further theoretical and experimental studies concerning electron-impact processes. 13 refs., 3 figs., 2 tabs. (WRF)

  14. Radar cross sections of standard and complex shape targets

    NASA Technical Reports Server (NTRS)

    Sohel, M. S.

    1974-01-01

    The theoretical, analytical, and experimental results are described for radar cross sections (RCS) of different-shaped targets. Various techniques for predicting RCS are given, and RCS of finite standard targets are presented. Techniques used to predict the RCS of complex targets are made, and the RCS complex shapes are provided.

  15. RZ calculations for self shielded multigroup cross sections

    SciTech Connect

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z.

    2006-07-01

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  16. 35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December 1941 by John Brackett, Consulting Engineer, to Public Works Department, Bureau of Yards & Docks. PW Drawing 3874-46, Y&D Drawing 190848. Scale 1/8' = 1'. - Naval Torpedo Station, Firing Pier, North end of Gould Island in Narragansett Bay, Newport, Newport County, RI

  17. The total neutron cross section of liquid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    1999-12-01

    We have measured, using the pulsed neutron source ISIS, the total neutron cross section of liquid para-hydrogen in the vicinity of the triple point. The experimental results compare only qualitatively with the results of the Young and Koppel theory. However, a much better agreement is found once modifications are included in the model which effectively take into account the intermolecular interactions.

  18. Cross-Sectional Imaging for Inflammatory Arthropathy of the Pelvis.

    PubMed

    Alian, Ali; Omar, Hythem; Chhabra, Avneesh

    2017-06-01

    Inflammatory arthropathy predominantly affecting the axial skeleton can cause pain, stiffness, disability, and ankylosis. This article discusses the use of cross-sectional imaging in the domain of inflammatory pelvic and axial arthropathy highlighting the key distinguishing features of common known diseases and their differential diagnoses. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Complex Correlation Calculation of e-H Total Cross Sections

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Temkin, Aaron; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Calculation of e - H total and elastic partial wave cross sections is being carried out using the complex correlation variational T-matrix method. In this preliminary study, elastic partial wave phase shifts are calculated with the correlation functions which are confined to be real. In that case the method reduces to the conventional optical potential approach with projection operators.

  20. Inclusive neutrino cross section measurements at MINERvA

    NASA Astrophysics Data System (ADS)

    Ratchford, Jasmine; Minerva Collaboration

    2011-10-01

    The MINERvA experiment is a precision neutrino experiment designed to improve our understanding of the neutrino-nucleus interaction. The experiment uses a fully active scintillation detector to allow full event reconstruction and includes passive targets helium, water, carbon, iron and lead. Preliminary measurements of inclusive cross section ratios of lead to iron will be shown.

  1. Quasi-Elastic Neutrino Cross Sections with MINERvA

    NASA Astrophysics Data System (ADS)

    Walding, Joe; Minerva Collaboration

    2011-10-01

    The MINERvA experiment will measure neutrino and antineutrino quasi-elastic scattering on helium, water, carbon, iron, and lead for neutrinos in the few GeV range. We will present preliminary results for quasi-elastic cross sections in the few GeV range on carbon. Supported in part by the US NSF.

  2. Stellar neutron capture cross sections of the tin isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Theis, C.; Kaeppeler, F.; Guber, K.; Kazakov, L.; Kornilov, N.; Reffo, G.

    1996-09-01

    The neutron capture cross sections of {sup 114}Sn, {sup 115}Sn, {sup 116}Sn, {sup 117}Sn, {sup 118}Sn, and {sup 120}Sn were measured in the energy range from 3 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li({ital p},{ital n}){sup 7}Be reaction using a pulsed proton beam. Capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The experiment was complicated by the small ({ital n},{gamma}) cross sections of the proton magic tin isotopes and by the comparably low enrichment of the rare isotopes {sup 114}Sn and {sup 115}Sn. Despite significant corrections for capture of scattered neutrons and for isotopic impurities, the high efficiency and the spectroscopic quality of the BaF{sub 2} detector allowed the determination of the cross-section ratios with overall uncertainties of 1{endash}2{percent}, five times smaller compared to existing data. Based on these results, Maxwellian averaged ({ital n},{gamma}) cross sections were calculated for thermal energies between {ital kT}=10 and 100 keV. These data are used for a discussion of the solar tin abundance and for an improved determination of the isotopic {ital s}- and {ital r}-process components. {copyright} {ital 1996 The American Physical Society.}

  3. Skin Diseases: Cross-section of human skin

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  4. Fission, total and neutron capture cross section measurements at ORELA

    SciTech Connect

    Guber, K.H.; Spencer, R.R.; Leal, L.C.; Larson, D.C.; Dos Santos, G.; Harvey, J.A.; Hill, N.W.

    1998-08-01

    In support of the Nuclear Criticality Predictability Program established in response to the Defense Nuclear Facility Safety Board Recommendation 93-2, time-of-flight (TOF) measurements of the fission cross sections of {sup 233}U in the neutron energy range from 0.36 eV to several hundred keV have been initiated at the Oak Ridge Electron Linear Accelerator (ORELA). Also total and capture cross sections of Al, Cl, and K in the energy range from about 100 eV to several hundred keV have been measured or are under way. The goal is to derive accurate cross section representations for the materials involved in criticality calculations of fuel storage, transportation, etc., configurations. Additional high-resolution measurements of the total cross sections of {sup 233}U below a few keV neutron energy are being planned for 1998, as well as for the other involved material. Evaluated data files in ENDF-6 format will be processed into formats for use in criticality analysis and utilized in benchmark data testing. Finally the data will be submitted for inclusion in ENDF/B.

  5. Ultrahigh energy neutrino-nucleon cross section and radiative corrections

    SciTech Connect

    Sigl, G.

    1998-03-01

    Several proposals exist to detect cosmic neutrinos of energy from tens of GeV up to the highest energies observed for cosmic rays, {approximately}10{sup 20}eV, or possibly even beyond. Detection efficiencies depend crucially on the neutrino-nucleon cross section at these energies at which radiative corrections beyond the lowest order approximation could become non-negligible. The differential cross sections can be modified by more than 50{percent} in some regions of phase space. Estimates of corrections to the quantities most relevant for neutrino detection at these energies give, however, less dramatic effects: The average inelasticity in the outgoing lepton is increased from {approx_equal}0.19 to {approx_equal}0.24. The inclusive cross section is reduced by roughly half a percent. The dominant uncertainty of the standard model ultrahigh energy neutrino-nucleon cross section therefore still comes from uncertainties of the parton distributions in the nucleon at very low momentum fractions. {copyright} {ital 1998} {ital The American Physical Society}

  6. The Inclusive Neutrino Charged Current Cross Section Measured in NOMAD

    NASA Astrophysics Data System (ADS)

    Godley, Andrew; Wu, Qun; Mishra, Sanjib

    2007-04-01

    The inclusive charged current cross section of muon neutrino interactions is measured as a function of energy using the NOMAD data. The significance of this measurement is its precision below 30 GeV, a region not previously well covered and of importance to current and proposed neutrino experiments. The procedure and results of the measurement will be presented.

  7. Electron-silane scattering cross section for plasma assisted processes

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Kaur, Jaspreet; Antony, Bobby

    2017-03-01

    Silane is an important molecule with numerous applications to natural and technological plasmas. In such environments, where plasma assisted processes are vital, electron induced reactions play a major role in its chemistry. In view of this, electron induced scattering of molecules such as silane finds significance. This article reports a comprehensive study of electron impact cross sections for silane over a wide energy range. In particular, the emphasis is given in providing a complete dataset for various electron scattering events possible with silane. Such dataset is the need for the plasma modeling community. Moreover, literature survey shows that the cross section database for silane is fragmentary. To fill this void, we have computed the differential elastic, total, rotational excitation, and momentum transfer cross sections. Two formalisms that are reliable in their energy domain are employed to accomplish the task: the R-matrix method through QUANTEMOL-N at low incident energies and the spherical complex optical potential formalism at intermediate to high energies. Interestingly, the comparison of the present cross section exhibits a good concurrence with the previous data, wherever available.

  8. Cross section measurements via residual nuclear decays: Analysis methods

    SciTech Connect

    Zhou Fengqun; Gao Lei; Li Kuohu; Song Yueli; Zhang Fang; Kong Xiangzhong; Luo Junhua

    2009-11-15

    We develop an approach to calculating the pure cross section of the ground state of artificial radioactive nuclides that subtracts the effect of an excited state on the ground state. We apply a formalism to obtaining pure cross sections by subtracting the effect of excited states in the reactions {sup 122}Te(n,2n){sup 121}Te{sup g} and {sup 128}Te(n,2n){sup 127}Te{sup g}, induced by neutrons of about 14 MeV. The cross sections are measured by an activation relative to the {sup 93}Nb(n,2n){sup 92}Nb{sup m} reaction and are compared with results that take into account the effect of the excited state. Measurements are carried out by {gamma} detection using a coaxial high-purity germanium (HPGe) detector. As samples, spectroscopically pure Te powder is used. The fast neutrons are produced by the {sup 3}H(d,n){sup 4}He reaction. The neutron energies in these measurements are determined using the method of cross-section ratios between the {sup 90}Zr(n,2n){sup 89}Zr{sup m+g} and {sup 93}Nb(n,2n){sup 92}Nb{sup m} reactions.

  9. Electron Impact Ionization Cross Sections of n-decane

    NASA Astrophysics Data System (ADS)

    Jiao, Charles; Dejoseph, Charles; Garscadden, Alan

    2001-10-01

    The ionization and dissociation of hydrocarbon fuels with various plasma excitation schemes including pulsed high E/n discharges have been proposed to alleviate the problem of ignition in supersonic flow combustors and operations at high altitudes. The fuel which is also used for cooling, must not pyrolyse at operational temperatures. We have examined the electron ionization collision processes in n-decane using high resolution Fourier transform mass spectrometry that permits measurements of the 24 ions with cross sections larger than 10-19cm2. These generally fall into two broad categories: those with five or more carbon atoms whose ionization cross sections rise rapidly and essentially saturate within twice the appearance potential and those with four carbon atoms and less whose cross sections rise more gradually and are only saturating at energies above 70 eV. The total ionization cross section is large, rising to 7x10-16cm2. Studies were made with deuterated samples to distinguish the potential mechanisms in fragment ion induced dissociation of the parent gas. The results are compared with similar data for octane.

  10. Proton-Helium Elastic Electromagnetic Cross-Section

    SciTech Connect

    Huang, Burn; Ng, Kingyuen B.

    2015-11-01

    In the test facility of the C-ADS project, A 25-MeV proton beam is directed to hit a target consisting of 1-mm tungsten balls lubricated by 100-Pa helium gas. To estimate the power loss to the helium gas, an accurate collision cross section is computed.

  11. Measuring cross sections using a sag tape: a generalized procedure

    Treesearch

    Gary A. Ray; Walter F. Megahan

    1979-01-01

    A procedure was developed for surveying cross sections using a sag tape with unequal end elevations. The procedure is as accurate as traditional engineer's level surveys, is faster and easier, and can be programed for a digital computer by following the flow diagram which is provided.

  12. Theory in evaluation of actinide fission and capture cross sections.

    SciTech Connect

    Lynn, J. E.

    2004-01-01

    The authors discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross-sections. They consider especially the target {sup 235}U as an example. They emphasize the roles of intermediate structure in the fission cross-section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross-section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross-section. They compare such estimates with evaluated and experimental data for {sup 235}U.

  13. Stellar neutron capture cross sections of the Lu isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.

    2006-01-15

    The neutron capture cross sections of {sup 175}Lu and {sup 176}Lu have been measured in the energy range 3-225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction by bombarding metallic Li targets with a pulsed proton beam, and capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The cross sections were determined relative to the gold standard using isotopically enriched as well as natural lutetium oxide samples. Overall uncertainties of {approx}1% could be achieved in the final cross section ratios to the gold standard, about a factor of 5 smaller than in previous works. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 and 100 keV. These values are systematically larger by {approx}7% than those reported in recent evaluations. These results are of crucial importance for the assessment of the s-process branchings at A 175/176.

  14. Reaction cross sections of carbon isotopes incident on a proton

    SciTech Connect

    Abu-Ibrahim, B.; Horiuchi, W.; Kohama, A.; Suzuki, Y.

    2008-03-15

    We systematically study total reaction cross sections of carbon isotopes with N=6-16 on a proton target for wide range of incident energies. An emphasis is put on the difference from the case of a carbon target. The calculations include the reaction cross sections of {sup 19,20,22}C at 40A MeV, the data of which have recently been measured at RIKEN. The Glauber theory is used to calculate the reaction cross sections. To describe the intrinsic structure of the carbon isotopes, we use a Slater determinant generated from a phenomenological mean-field potential, and construct the density distributions. To go beyond the simple mean-field model, we adopt two types of dynamical models: One is a core+n model for odd-neutron nuclei, and the other is a core+n+n model for {sup 16}C and {sup 22}C. We propose empirical formulas which are useful in predicting unknown cross sections.

  15. Pion Charge Exchange Cross Section on Liquid Argon

    NASA Astrophysics Data System (ADS)

    Nelson, Kevin; LArIAT (FNAL T-1034) Collaboration

    2017-01-01

    The observation of neutrino oscillations allows charge parity violation to be probed in the neutrino sector. Detectors with high calorimetric energy resolution and high spatial resolution will provide precise measurements of neutrino oscillations. By measuring small π+/- cross sections for individual interaction channels, specifically charge exchange, we will make a measurement in the first of its kind on liquid Argon and demonstrate the physics capabilities of a relatively new detector technology: the Liquid Argon Time Projection Chamber (LAr TPC). This analysis will report on the thin slab cross section measurement technique and the Monte Carlo cross section measurements in the energy range of 0.2 - 1.0 GeV. This analysis is the first iteration in classifying charge exchange events from a sample of incident pions, and it aims to identify events in which a π0 was produced without any charged pions leaving the interaction vertex. We will also report on the methodology and efficiency of this algorithm in identifying particles and their interactions in liquid argon. This analysis will inform a future measurement of the π+/- charge exchange cross section on liquid argon. This work was supported in part by the National Science Foundation under Grant No. PHY-1359364.

  16. Service building. Cross section thru dry dock nos. 4 & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Service building. Cross section thru dry dock nos. 4 & 5 showing service bldg & 20-75-150 ton cranes (dry dock associates, May 23, 1941). In files of Cushman & Wakefield, building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Service Building, Dry Docks No. 4 & 5, League Island, Philadelphia, Philadelphia County, PA

  17. Measurement of proton inelastic scattering cross sections on fluorine

    NASA Astrophysics Data System (ADS)

    Chiari, M.; Caciolli, A.; Calzolai, G.; Climent-Font, A.; Lucarelli, F.; Nava, S.

    2016-10-01

    Differential cross-sections for proton inelastic scattering on fluorine, 19F(p,p')19F, from the first five excited levels of 19F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm2) evaporated on a self-supporting C thin film (30 μg/cm2). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF2) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

  18. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    DOE PAGES

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; ...

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  19. Thermal neutron capture cross sections of the potassium isotopes

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Krtička, M.; Révay, Zs.; Szentmiklosi, L.; Belgya, T.

    2013-02-01

    Precise thermal neutron capture γ-ray cross sections σγ for 39,40,41K were measured on a natural potassium target with the guided neutron beam at the Budapest Reactor. The cross sections were internally standardized using a stoichiometric KCl target with well-known 35Cl(n,γ) γ-ray cross sections [Révay and Molnár, Radiochimica ActaRAACAP0033-823010.1524/ract.91.6.361.20027 91, 361 (2003); Molnár, Révay, and Belgya, Nucl. Instrum. Meth. Phys. Res. BNIMBEU0168-583X10.1016/S0168-583X(03)01529-5 213, 32 (2004)]. These data were combined with γ-ray intensities from von Egidy [von Egidy, Daniel, Hungerford, Schmidt, Lieb, Krusche, Kerr, Barreau, Borner, Brissot , J. Phys. G. Nucl. Phys.JPHGBM0305-461610.1088/0305-4616/10/2/013 10, 221 (1984)] and Krusche [Krusche, Lieb, Ziegler, Daniel, von Egidy, Rascher, Barreau, Borner, and Warner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(84)90506-2 417, 231 (1984); Krusche, Winter, Lieb, Hungerford, Schmidt, von Egidy, Scheerer, Kerr, and Borner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(85)90429-4 439, 219 (1985)] to generate nearly complete capture γ-ray level schemes. Total radiative neutron cross sections were deduced from the total γ-ray cross section feeding the ground state, σ0=Σσγ(GS) after correction for unobserved statistical γ-ray feeding from levels near the neutron capture energy. The corrections were performed with Monte Carlo simulations of the potassium thermal neutron capture decay schemes using the computer code dicebox where the simulated populations of low-lying levels are normalized to the measured cross section depopulating those levels. Comparisons of the simulated and experimental level feeding intensities have led to proposed new spins and parities for selected levels in the potassium isotopes where direct reactions are not a significant contribution. We determined the total radiative neutron cross sections σ0(39K)=2.28±0.04 b, σ0(40K)=90±7 b, and σ0(41K)=1.62±0.03 b from the

  20. Electron impact ionisation cross sections of iron hydrogen clusters

    NASA Astrophysics Data System (ADS)

    Huber, Stefan E.; Sukuba, Ivan; Urban, Jan; Limtrakul, Jumras; Probst, Michael

    2016-09-01

    We computed electron impact ionisation cross sections (EICSs) of iron hydrogen clusters, FeH n with n = 1,2, ...,10, from the ionisation threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The maxima of the cross sections for the iron hydrogen clusters range from 6.13 × 10-16 cm2 at 60 eV to 8.76 × 10-16 cm2 at 76 eV for BEB-AE (BEB method based on quantum-chemical data from all-electron basis sets) calculations, from 4.15 × 10-16 cm2 at 77 eV to 7.61 × 10-16 cm2 at 80 eV for BEB-ECP (BEB method based on quantum-chemical data from effective-core potentials for inner-core electrons) calculations and from 2.49 × 10-16 cm2 at 43.5 eV to 7.04 × 10-16 cm2 at 51 eV for the DM method. Cross sections calculated via the BEB method are substantially higher than the ones obtained via the DM method, up to a factor of about two for FeH and FeH2. The formation of Fe-H bonds depopulates the iron 4 s orbital, causing significantly lower cross sections for the small iron hydrides compared to atomic iron. Both the DM and BEB cross sections can be fitted perfectly against a simple expression used in modelling and simulation codes in the framework of nuclear fusion research. The energetics of the iron hydrogen clusters change substantially when exact exchange is present in the density functional, while the cluster geometries do not depend on this choice.

  1. Turbulent combustion flow through variable cross section channel

    SciTech Connect

    Rogov, B.V.; Sokolova, I.A.

    1999-07-01

    The object of this study is to develop a new evolutionary numerical method for solving direct task of Laval nozzle, which provides non-iterative calculations of chemical reacting turbulent flows with detailed kinetic chemistry. The numerical scheme of fourth order along the normal coordinate and second order along the streamwise one is derived for calculation of difference-differential equations of the second order and the first order. Marching method provides the possibility of computing field flow in subsonic section of nozzle and near an expansion. Critical mass consumption is calculated with controlled accuracy. After critical cross section of nozzle a combined marching method with global iterations over axial pressure (only) makes it possible to overcome ill posedness of mixed supersonic flow and calculate the whole flow field near and after critical cross section. Numerical results are demonstrated on turbulent burning hydrogen-oxygen flow through Laval nozzle with curvature of wall K{sub w} = 0.5.

  2. Total electron scattering and electronic state excitations cross sections for O2, CO, and CH4

    NASA Technical Reports Server (NTRS)

    Kanik, I.; Trajmar, S.; Nickel, J. C.

    1993-01-01

    Available electron collision cross section data concerning total and elastic scattering, vibrational excitation, and ionization for O2, CO, and CH4 have been critically reviewed, and a set of cross sections for modeling of planetary atmospheric behavior is recommended. Utilizing these recommended cross sections, we derived total electronic state excitation cross sections and upper limits for dissociation cross sections, which in the case of CH4 should very closely equal the actual dissociation cross section.

  3. Calculation of photoionization cross section near auto-ionizing lines and magnesium photoionization cross section near threshold

    NASA Technical Reports Server (NTRS)

    Moore, E. N.; Altick, P. L.

    1972-01-01

    The research performed is briefly reviewed. A simple method was developed for the calculation of continuum states of atoms when autoionization is present. The method was employed to give the first theoretical cross section for beryllium and magnesium; the results indicate that the values used previously at threshold were sometimes seriously in error. These threshold values have potential applications in astrophysical abundance estimates.

  4. Novel Method for Vessel Cross-Sectional Shear Wave Imaging.

    PubMed

    He, Qiong; Li, Guo-Yang; Lee, Fu-Feng; Zhang, Qihao; Cao, Yanping; Luo, Jianwen

    2017-07-01

    Many studies have investigated the applications of shear wave imaging (SWI) to vascular elastography, mainly on the longitudinal section of vessels. It is important to investigate SWI in the arterial cross section when evaluating anisotropy of the vessel wall or complete plaque composition. Here, we proposed a novel method based on the coordinate transformation and directional filter in the polar coordinate system to achieve vessel cross-sectional shear wave imaging. In particular, ultrasound radiofrequency data were transformed from the Cartesian to the polar coordinate system; the radial displacements were then estimated directly. Directional filtering was performed along the circumferential direction to filter out the reflected waves. The feasibility of the proposed vessel cross-sectional shear wave imaging method was investigated through phantom experiments and ex vivo and in vivo studies. Our results indicated that the dispersion relation of the shear wave (i.e., the guided circumferential wave) within the vessel can be measured via the present method, and the elastic modulus of the vessel can be determined. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Microscopic description of production cross sections including deexcitation effects

    NASA Astrophysics Data System (ADS)

    Sekizawa, Kazuyuki

    2017-07-01

    Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable. Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compound-nucleus deexcitation model, GEMINI++. Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using the particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wave function after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely used grazing calculations. Results: The method is applied to describe cross sections for multinucleon transfer processes in 40Ca+124Sn (Ec .m .≃128.54 MeV ), 48Ca+124Sn (Ec .m .≃125.44 MeV ), 40Ca+208Pb (Ec .m .≃208.84 MeV ), 58Ni+208Pb (Ec .m .≃256.79 MeV ), 64Ni+238U (Ec .m .≃307.35 MeV ), and 136Xe+198Pt (Ec .m .≃644.98 MeV ) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in grazing calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one proton, compared to the grazing

  6. Developing Scientific Reasoning Through Drawing Cross-Sections

    NASA Astrophysics Data System (ADS)

    Hannula, K. A.

    2012-12-01

    Cross-sections and 3D models of subsurface geology are typically based on incomplete information (whether surface geologic mapping, well logs, or geophysical data). Creating and evaluating those models requires spatial and quantitative thinking skills (including penetrative thinking, understanding of horizontality, mental rotation and animation, and scaling). However, evaluating the reasonableness of a cross-section or 3D structural model also requires consideration of multiple possible geometries and geologic histories. Teaching students to create good models requires application of the scientific methods of the geosciences (such as evaluation of multiple hypotheses and combining evidence from multiple techniques). Teaching these critical thinking skills, especially combined with teaching spatial thinking skills, is challenging. My Structural Geology and Advanced Structural Geology courses have taken two different approaches to developing both the abilities to visualize and to test multiple models. In the final project in Structural Geology (a 3rd year course with a pre-requisite sophomore mapping course), students create a viable cross-section across part of the Wyoming thrust belt by hand, based on a published 1:62,500 geologic map. The cross-section must meet a number of geometric criteria (such as the template constraint), but is not required to balance. Each student tries many potential geometries while trying to find a viable solution. In most cases, the students don't visualize the implications of the geometries that they try, but have to draw them and then erase their work if it does not meet the criteria for validity. The Advanced Structural Geology course used Midland Valley's Move suite to test the cross-sections that they made in Structural Geology, mostly using the flexural slip unfolding algorithm and testing whether the resulting line lengths balanced. In both exercises, students seemed more confident in the quality of their cross-sections when the

  7. Medical Student Knowledge of Neglected Tropical Diseases in Peru: A Cross-Sectional Study.

    PubMed

    Errea, Renato A; Vasquez-Rios, George; Machicado, Jorge D; Gallardo, Maria Susana; Cornejo, Marilhia; Urquiaga, Jorge F; Montoya, Diego; Zamudio, Rodrigo; Terashima, Angelica; Marcos, Luis A; Samalvides, Frine

    2015-11-01

    In developing countries, education to health-care professionals is a cornerstone in the battle against neglected tropical diseases (NTD). Studies evaluating the level of knowledge of medical students in clinical and socio-demographic aspects of NTD are lacking. Therefore, a cross-sectional study was conducted among students from a 7 year-curriculum medical school in Peru to assess their knowledge of NTD by using a pilot survey comprised by two blocks of 10 short questions. Block I consisted of socio-demographic and epidemiological questions whereas block II included clinical vignettes. Each correct answer had the value of 1 point. Out of 597 responders (response rate: 68.4%), 583 were considered to have valid surveys (male:female ratio: 1:1.01; mean age 21 years, SD ± 2.42). Total knowledge showed a raising trend through the 7-year curriculum. Clinical knowledge seemed to improve towards the end of medical school whereas socio-demographic and epidemiological concepts only showed progress the first 4 years of medical school, remaining static for the rest of the curricular years (p = 0.66). Higher mean scores in socio-demographic and epidemiological knowledge compared to clinical knowledge were seen in the first two years (p<0.001) whereas the last three years showed higher scores in clinical knowledge (p<0.001). In conclusion, students from this private medical school gained substantial knowledge in NTD throughout the career which seems to be related to improvement in clinical knowledge rather than to socio-demographic and epidemiological concepts. This study assures the feasibility of measuring the level of knowledge of NTD in medical students and stresses the importance of evaluating education on NTD as it may need more emphasis in epidemiological concepts, especially at developing countries such as Peru where many people are affected by these preventable and treatable diseases.

  8. Medical Student Knowledge of Neglected Tropical Diseases in Peru: A Cross-Sectional Study

    PubMed Central

    Errea, Renato A.; Vasquez-Rios, George; Machicado, Jorge D.; Terashima, Angelica; Marcos, Luis A.; Samalvides, Frine

    2015-01-01

    In developing countries, education to health-care professionals is a cornerstone in the battle against neglected tropical diseases (NTD). Studies evaluating the level of knowledge of medical students in clinical and socio-demographic aspects of NTD are lacking. Therefore, a cross-sectional study was conducted among students from a 7 year-curriculum medical school in Peru to assess their knowledge of NTD by using a pilot survey comprised by two blocks of 10 short questions. Block I consisted of socio-demographic and epidemiological questions whereas block II included clinical vignettes. Each correct answer had the value of 1 point. Out of 597 responders (response rate: 68.4%), 583 were considered to have valid surveys (male:female ratio: 1:1.01; mean age 21 years, SD ± 2.42). Total knowledge showed a raising trend through the 7-year curriculum. Clinical knowledge seemed to improve towards the end of medical school whereas socio-demographic and epidemiological concepts only showed progress the first 4 years of medical school, remaining static for the rest of the curricular years (p = 0.66). Higher mean scores in socio-demographic and epidemiological knowledge compared to clinical knowledge were seen in the first two years (p<0.001) whereas the last three years showed higher scores in clinical knowledge (p<0.001). In conclusion, students from this private medical school gained substantial knowledge in NTD throughout the career which seems to be related to improvement in clinical knowledge rather than to socio-demographic and epidemiological concepts. This study assures the feasibility of measuring the level of knowledge of NTD in medical students and stresses the importance of evaluating education on NTD as it may need more emphasis in epidemiological concepts, especially at developing countries such as Peru where many people are affected by these preventable and treatable diseases. PMID:26523733

  9. Fast-neutron scattering cross sections of elemental silver

    SciTech Connect

    Smith, A.B.; Guenther, P.T.

    1982-05-01

    Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160/sup 0/. Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V.

  10. Characterization of Single Event Latchup Cross-Section for ALPIDE

    NASA Astrophysics Data System (ADS)

    Szornel, Joanna; Michael, Elad; Torales-Acosta, Fernando; Greiner, Leo; Jacak, Barbara

    2015-10-01

    Latchup cross-section was characterized for a prototype of ALPIDE (ALICE PIxel DEtector), a silicon pixel detector proposed for use in the ALICE inner tracking system. Before being implemented, the sensor needs to be tested to verify its effectiveness. When active it will be subject to bombardment from energetic ions which can cause single event latchups (SELs). These occur when parasitic effects result in short-circuits, causing potentially damaging increases in current. Ions with various LETs (5 - 40 MeV) were used to induce SELs whereupon event cross-section was measured. The likelihood of the sensor experiencing SEL increases with greater ion LET and fluence. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Nuclear Physics.

  11. Differential cross sections for muonic atom scattering from hydrogenic molecules

    SciTech Connect

    Adamczak, Andrzej

    2006-10-15

    The differential cross sections for low-energy muonic hydrogen atom scattering from hydrogenic molecules are directly expressed by the corresponding amplitudes for muonic atom scattering from hydrogen-isotope nuclei. The energy and angular dependence of these three-body amplitudes is thus taken naturally into account in scattering from molecules, without involving any pseudopotentials. Effects of the internal motion of nuclei inside the target molecules are included for every initial rotational-vibrational state. These effects are very significant as the considered three-body amplitudes often vary strongly within the energy interval < or approx. 0.1 eV. The differential cross sections, calculated using the presented method, have been successfully used for planning and interpreting many experiments in low-energy muon physics. Studies of {mu}{sup -} nuclear capture in p{mu} and the measurement of the Lamb shift in p{mu} atoms created in H{sub 2} gaseous targets are recent examples.

  12. Neutron Capture Cross Sections of 236U and 234U

    SciTech Connect

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Kronenberg, A.

    2006-03-13

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-{pi} solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  13. Neutron inelastic cross section measurements for natTi

    NASA Astrophysics Data System (ADS)

    Olacel, Adina; Belloni, Francesca; Borcea, Catalin; Boromiza, Marian; Dessagne, Philippe; Henning, Gregoire; Kerveno, Maëlle; Negret, Alexandru; Nyman, Markus; Pirovano, Elisa; Plompen, Arjan

    2017-09-01

    A neutron inelastic scattering experiment was performed at the GELINA (Geel Electron LINear Accelerator) neutron source of the European Commission Joint Research Centre Geel (EC-JRC Geel) with the aim of determining the reaction cross sections for the stable isotopes of natural titanium. A 235U fission chamber was used to monitor neutrons with energies up to 20 MeV. The GAINS (Gamma Array for Inelastic Neutron Scattering) spectrometer was employed to detect the γ rays resulting from the decay of the excited nuclei. We determined the γ-ray production cross sections of the first transitions in the 46,48,49,50Ti isotopes. The experimental values were compared with previous reported results and also with theoretical calculations performed with the TALYS 1.8 code using the default input parameters. Uncertainties of around 5% were obtained for the strongest observed transitions.

  14. Probing neutron-skin thickness with total reaction cross sections

    NASA Astrophysics Data System (ADS)

    Horiuchi, W.; Suzuki, Y.; Inakura, T.

    2014-01-01

    We analyze total reaction cross sections, σR, to explore their sensitivity to the neutron-skin thickness of nuclei. We cover 91 nuclei of O, Ne, Mg, Si, S, Ca, and Ni isotopes. The cross sections are calculated in the Glauber theory using the density distributions obtained with the Skyrme-Hartree-Fock method in three-dimensional coordinate space. Defining a reaction radius, aR=√σR/π , to characterize the nuclear size and target (proton or 12C) dependence, we find an empirical formula for expressing aR with the point matter radius and the skin thickness, and assess two practical ways of determining the skin thickness from proton-nucleus σR values measured at different energies or from σR values measured for different targets.

  15. Measurement of correlated b quark cross sections at CDF

    SciTech Connect

    CDF Collaboration

    1994-05-01

    Using data collected during the 1992--1993 collider run at Fermilab, CDF has made measurements of correlated b quark cross sections where one b is detected from the lepton from semileptonic decay and the second b is detected with secondary vertex techniques. We report on measurements of the cross section as a function of the momentum of the second b and as a function of the azimuthal separation of the two b quarks, for transverse momentum of the initial b quark greater than 15 GeV. The vertex reconstruction techniques are valid over a large range in transverse momentum, starting at a minimum of 10 GeV. Results are compared to QCD predictions.

  16. Measurements of Radiative Capture Cross Sections at Big Bang Energies

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaomi; Fukuda, Mitsunori; Tanaka, Yutaro; Du, Hang; Ohnishi, Kousuke; Yagi, Shoichi; Sugihara, Takanobu; Hori, Taichi; Nakamura, Shoken; Yanagihara, Rikuto; Matsuta, Kensaku; Mihara, Mototsugu; Nishimura, Daiki; Iwakiri, Shuichi; Kambayashi, Shohei; Kunimatsu, Shota; Sakakibara, Hikaru; Yamaoka, Shintaro

    We measured d(p, γ )3He cross sections at ECM = 0.12, 0.19, 0.44, and 0.57 MeV. In this energy region, available experimental values are systematically smaller than the recent calculation, so that additional experiments are desired for understanding the Big Bang Nucleosynthesis. The experiment was performed by bombarding proton beams to the D2 gas target with the 5 MV Van de Graaff accelerator at Osaka University. The experimental d(p, γ )3He cross sections of the present study are systematically larger than previous data. On the other hand, recent theoretical results by Marcucci et al. are in good agreement with present experimental results.

  17. Shrink-wrapped isosurface from cross sectional images.

    PubMed

    Choi, Y K; Hahn, J K

    2007-12-01

    This paper addresses a new surface reconstruction scheme for approximating the isosurface from a set of tomographic cross sectional images. Differently from the novel Marching Cubes (MC) algorithm, our method does not extract the iso-density surface (isosurface) directly from the voxel data but calculates the iso-density point (isopoint) first. After building a coarse initial mesh approximating the ideal isosurface by the cell-boundary representation, it metamorphoses the mesh into the final isosurface by a relaxation scheme, called shrink-wrapping process. Compared with the MC algorithm, our method is robust and does not make any cracks on surface. Furthermore, since it is possible to utilize lots of additional isopoints during the surface reconstruction process by extending the adjacency definition, theoretically the resulting surface can be better in quality than the MC algorithm. According to experiments, it is proved to be very robust and efficient for isosurface reconstruction from cross sectional images.

  18. Very high energy proton-proton cross section

    NASA Astrophysics Data System (ADS)

    Wibig, Tadeusz

    2009-05-01

    The recent Pierre Auger Observatory result suggesting a coincidence of extensive air showers arrival directions with “nearby” active galactic nuclei and HiRes discovery of the Greisen-Zatsepin-Kuzmin cutoff indicates protons to be only or at least the strongly dominant component of primary extra galactic cosmic ray flux. However, showers initiated by these ultrahigh energy particles developed faster than predicted by the simulation calculations with conventional interaction models. This could be evidence of the substantial increase of the p-air cross section. The progress in understanding the proton-proton cross section description allows us to examine this possibility, and eventually reject it as an explanation of the ultrahigh energy cosmic ray “pure proton” controversy.

  19. Very high energy proton-proton cross section

    SciTech Connect

    Wibig, Tadeusz

    2009-05-01

    The recent Pierre Auger Observatory result suggesting a coincidence of extensive air showers arrival directions with 'nearby' active galactic nuclei and HiRes discovery of the Greisen-Zatsepin-Kuzmin cutoff indicates protons to be only or at least the strongly dominant component of primary extra galactic cosmic ray flux. However, showers initiated by these ultrahigh energy particles developed faster than predicted by the simulation calculations with conventional interaction models. This could be evidence of the substantial increase of the p-air cross section. The progress in understanding the proton-proton cross section description allows us to examine this possibility, and eventually reject it as an explanation of the ultrahigh energy cosmic ray 'pure proton' controversy.

  20. Accurate Development of Thermal Neutron Scattering Cross Section Libraries

    SciTech Connect

    Hawari, Ayman; Dunn, Michael

    2014-06-10

    The objective of this project is to develop a holistic (fundamental and accurate) approach for generating thermal neutron scattering cross section libraries for a collection of important enutron moderators and reflectors. The primary components of this approach are the physcial accuracy and completeness of the generated data libraries. Consequently, for the first time, thermal neutron scattering cross section data libraries will be generated that are based on accurate theoretical models, that are carefully benchmarked against experimental and computational data, and that contain complete covariance information that can be used in propagating the data uncertainties through the various components of the nuclear design and execution process. To achieve this objective, computational and experimental investigations will be performed on a carefully selected subset of materials that play a key role in all stages of the nuclear fuel cycle.

  1. Ion induced fragmentation cross-sections of DNA constituents

    NASA Astrophysics Data System (ADS)

    Rudek, Benedikt; Arndt, Alexander; Bennett, Daniel; Wang, Mingjie; Rabus, Hans

    2015-10-01

    Proton collision with chemical analogs for the base, the sugar and the phosphor residue of the DNA, namely pyrimidine, tetrahydrofuran and trimethyl phosphate, respectively, has been investigated. The impact energies ranged from 300 keV up to 16 MeV. For the first time, relative fragmentation cross-sections for proton impact are reported for tetrahydrofuran and trimethyl phosphate; previously reported cross sections for pyrimidine are extended for energies beyond 2500 keV. Ionization of tetrahydrofuran leads to a ring break in about 80% of all events, trimethyl phosphate predominantly fragments by bond cleavage to one of the three methyl-groups and for pyrimidine the parent ion has the highest abundance. Such comparison supports earlier findings that the sugar is the weak spot for strand breaks.

  2. Tearing instability in a tokamak with a noncircular cross section

    SciTech Connect

    Arsenin, V. V. Skovoroda, A. A.

    2016-12-15

    Using a straight-column model to describe tokamak plasma with a noncircular cross section, it is shown how to (i) find the boundary of tearing instability from the condition of existence of a magnetohydrodynamic plasma equilibrium different from that of a straight cylinder by solving a two-dimensional linear boundary-value problem with a second-order equation with respect to the flux coordinate and (ii) find the spatial structure of the tearing mode and the corresponding effective Δ' when there is only one resonance magnetic surface in the plasma for a given axial wavenumber by solving some kind of a boundary-value problem for the perturbation. The proposed approach is illustrated by numerical calculations for the case of an elliptical cross section as an example.

  3. Electron impact cross sections applicable to molecular lasers

    NASA Astrophysics Data System (ADS)

    Wong, S. F.

    1981-08-01

    In the program on excited molecules we have completed the experiments on dissociative attachment from vibrationally excited HCl and HF. In this work we observed an unusually large cross section (10 to the -14th power sq cm.) for Cl-/HCl (v=2) and proposed a new mechanism for dissociative attachment by electron impact. These results have been published in Journal of Chemical Physics, 1981. In the program on electronic excitation of noble-gas atoms we have established the experimental methods for studies up to the threshold region. The first results have been obtained for the n=2 states of He, within 4 eV of threshold. In the 2 3S and 2 3P cross sections we observed anomalous angular dependences attributable to a new 2P resonance.

  4. Tearing instability in a tokamak with a noncircular cross section

    NASA Astrophysics Data System (ADS)

    Arsenin, V. V.; Skovoroda, A. A.

    2016-12-01

    Using a straight-column model to describe tokamak plasma with a noncircular cross section, it is shown how to (i) find the boundary of tearing instability from the condition of existence of a magnetohydrodynamic plasma equilibrium different from that of a straight cylinder by solving a two-dimensional linear boundary-value problem with a second-order equation with respect to the flux coordinate and (ii) find the spatial structure of the tearing mode and the corresponding effective Δ' when there is only one resonance magnetic surface in the plasma for a given axial wavenumber by solving some kind of a boundary-value problem for the perturbation. The proposed approach is illustrated by numerical calculations for the case of an elliptical cross section as an example.

  5. Carbon Fragmentation Cross Sections for Hadrontherapy and Space Radiation Protection

    NASA Astrophysics Data System (ADS)

    De Napoli, M.; Agodi, C.; Cirrone, G. A. P.; Cuttone, G.; Nicolosi, D.; Pandola, L.; Raciti, G.; Romano, F.; Sardina, D.; Scuderi, V.; Tropea, S.; Bondì, M.; Cappuzzello, F.; Carbone, D.; Cavallaro, M.

    2014-05-01

    Fragmentation reactions represent a serious complication in hadrontherapy and space radiation protection. In order to predict their effects, both reliable Monte Carlo codes and experimental data are needed. The shortage of precise measurements, especially of double differential cross sections, has triggered many dedicated experiments at relativistic energies. Aiming to explore the Fermi energy regime, as well, where different reaction mechanisms are involved, we measured the 12C fragmentation at 62 AMeV on a 12C and a 197Au target. A high granularity Si-CsI hodoscope allowed to identify the charge and the mass of detected fragments and measure their energy and emission angle. In this work we report the double differential cross sections for the production of different fragments as a function of the emission angle. Experimental results are compared with the GEANT-4 Monte Carlo predictions performed using two reaction models, the Quantum Molecular Dynamic and the Binary Light Ion Cascade.

  6. Absolute measurements of chlorine Cl+ cation single photoionization cross section

    NASA Astrophysics Data System (ADS)

    Hernández, E. M.; Juárez, A. M.; Kilcoyne, A. L. D.; Aguilar, A.; Hernández, L.; Antillón, A.; Macaluso, D.; Morales-Mori, A.; González-Magaña, O.; Hanstorp, D.; Covington, A. M.; Davis, V.; Calabrese, D.; Hinojosa, G.

    2015-01-01

    The photoionization of Cl+ leading to Cl2+ was measured in the photon energy range of 19.5-28.0 eV. A spectrum with a photon energy resolution of 15 meV normalized to absolute cross-section measurements is presented. The measurements were carried out by merging a Cl+ ion beam with a photon beam of highly monochromatic synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory. The measured photoionization of Cl+ consists of several autoionization resonances surperimposed on the direct photoionization signal. Most of the prominent resonances are assigned to members of Rydberg series originating from the singlet ground state and from metastable triplet levels within the ground-state configuration of Cl+. The direct ionization cross section is no larger than 12 Mb.

  7. Ocean surface cross sections for shipborne HFSWR with sway motion

    NASA Astrophysics Data System (ADS)

    Sun, Minglei; Xie, Junhao; Ji, Zhenyuan; Yao, Guowei

    2016-11-01

    To interpret the essential characteristics of the sea echo backscattered from the ocean surface, the first- and second-order ocean surface cross sections are mathematically derived for an omnidirectional receiving sensor in monostatic shipborne high-frequency surface wave radar (HFSWR), where the uniform linear motion and sway motion are involved simultaneously. The derived cross sections could be reduced to the existing results in HFSWR on a floating platform, shipborne HFSWR with uniform linear motion, and even a stationary land-based HFSWR. The illustrations and discussions are presented based on the simulated Doppler spectra under different situations. Aside from the Bragg lines broadening due to the uniform linear motion and its variation with wind direction, the sway motion generates additional Doppler spectra, which emerge with the uniform spacing of sway frequency. The theoretical derivations and analyses based on simulations may be of importance to future investigations and applications, not only in target detection but also in ocean remote sensing.

  8. Calculation of the cross section for top quark production

    SciTech Connect

    Berger, E.L.; Contopanagos, H.

    1996-06-21

    The authors summarize calculations of the cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength. In their approach they resume the universal leading-logarithm contributions, and they restrict the calculation to the region of phase space that is demonstrably perturbative. They compare the approach with other methods. They present predictions of the physical cross section as a function of the top quark mass in proton-antiproton reactions at center-of-mass energies of 1.8 and 2.0 TeV, and they discuss estimated uncertainties.

  9. Extinction cross-section suppression and active acoustic invisibility cloaking

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2017-10-01

    Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility.

  10. Improved activation cross sections for vanadium and titanium

    SciTech Connect

    Muir, D.W.; Arthur, E.D.

    1983-01-01

    Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in /sup 50/V and /sup 51/V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions /sup 46/Ti(n,2n) and /sup 45/Ti(n,2n) in order to estimate the production of /sup 44/Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years.

  11. Krypton Production Cross Sections and Production Rates in Simulation Experiments

    NASA Astrophysics Data System (ADS)

    Gilabert, E.; Lavielle, B.; Schiekel, Th.; Herpers, U.; Neumann, S.; Michel, R.

    1995-09-01

    The stacked-foil technique was used to measured proton induced excitation functions from Sr targets (SrF2). The irradiations were performed at the Laboratoire National Saturne in Saclay (F), the Svedberg Laboratory in Uppsala (S) and the Paul Scherrer Institute in Villigen (CH) with primary energies from 45 to 400 MeV. After gamma-spectrometric measurement of short and medium-lived radionuclides and after sufficient cooling, stable and long lived Kr isotopes were measured at Centre Etude Nucleaire in Bordeaux (F). Deduced cross sections were corrected for the production of secondary protons and neutrons by a method developed by Lupke[1]. There are no literature data which can be compared with the cross sections from this work. Theoretical calculations of cross sections were performed using two approaches. The first one was using the hybrid model of preequilibrium reactions with the code AREL[2]. The second was using the Intra-Nuclear-Cascade/Evaporation model in the form of the High Energy Transport Code (HETC)[3]. This study shows that for energies above 200 MeV, the spallation model is better suited to explain the nuclear reactions whereas the preequilibrium model leads to underestimation of the experimental data. For energies above 200 MeV, HETC should be preferred to AREL calculations. In physical models describing galactic cosmic ray (GCR) interactions with matter [4], cross sections of both, proton and neutron-induced reactions, are important parameters. Using the measured cross sections for proton-induced reactions from this work and the experimental Kr depth profiles obtained from Sr targets in the LNS172 simulation experiment [5], we established a set of excitation functions for neutron-induced reactions, which now excellently describes the production rate depth profiles from the simulation experiment. Before measuring experimental cross sections for Kr from Sr, the theoretical depth profiles calculated with pure theoretical excitation functions showed

  12. Intermanifold similarities in partial photoionization cross sections of helium

    NASA Astrophysics Data System (ADS)

    Schneider, Tobias; Liu, Chien-Nan; Rost, Jan-Michael

    2002-04-01

    Using the eigenchannel R-matrix method we calculate partial photoionization cross sections from the ground state of the helium atom for incident photon energies up to the N=9 manifold. The wide energy range covered by our calculations permits a thorough investigation of general patterns in the cross sections which were first discussed by Menzel and coworkers [Phys. Rev. A 54, 2080 (1996)]. The existence of these patterns can easily be understood in terms of propensity rules for autoionization. As the photon energy is increased the regular patterns are locally interrupted by perturber states until they fade out indicating the progressive breakdown of the propensity rules and the underlying approximate quantum numbers. We demonstrate that the destructive influence of isolated perturbers can be compensated with an energy-dependent quantum defect.

  13. Vortex breakdown in closed containers with polygonal cross sections

    SciTech Connect

    Naumov, I. V. Dvoynishnikov, S. V.; Kabardin, I. K.; Tsoy, M. A.

    2015-12-15

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results.

  14. Evaluation of Neutron Resonance Cross Section Data at GELINA

    NASA Astrophysics Data System (ADS)

    Schillebeeckx, P.; Becker, B.; Capote, R.; Emiliani, F.; Guber, K.; Heyse, J.; Kauwenberghs, K.; Kopecky, S.; Lampoudis, C.; Massimi, C.; Mondelaers, W.; Moxon, M.; Noguere, G.; Plompen, A. J. M.; Pronyaev, V.; Siegler, P.; Sirakov, I.; Trkov, A.; Volev, K.; Zerovnik, G.

    2014-05-01

    Over the last decade, the EC-JRC-IRMM, in collaboration with other institutes such as INRNE Sofia (BG), INFN Bologna (IT), ORNL (USA), CEA Cadarache (FR) and CEA Saclay (FR), has made an intense effort to improve the quality of neutron-induced cross section data in the resonance region. These improvements relate to both the infrastructure of the facility and the measurement setup, and the data reduction and analysis procedures. As a result total and reaction cross section data in the resonance region with uncertainties better than 0.5 % and 2 %, respectively, can be produced together with evaluated data files for both the resolved and unresolved resonance region. The methodology to produce full ENDF compatible files, including covariances, is illustrated by the production of resolved resonance parameter files for 241Am, Cd and W and an evaluation for 197Au in the unresolved resonance region.

  15. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    SciTech Connect

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  16. Total Electron Scattering Cross Sections for Simple Perfluorocarbons

    NASA Astrophysics Data System (ADS)

    Nishimura, Hiroyuki; Nishimura, Fumio; Nakamura, Yoshiharu; Okuda, Keisuke

    2003-05-01

    Total electron scattering cross sections for CF4, C2F6 and C3F8 have been measured in the energy range between 1.25 eV and 3000 eV using a compact linear transmission apparatus. Electrons scattered into a narrow forward angular range that should be counted in the scattered one were estimated utilizing measured quantities. The present results for CF4 agree well with available data at low and high energies, while some discrepancies were seen at intermediate energies. Measured results for C2F6 and C3F8 were shown at high energies for the first time. Upper bound of the elastic cross sections for these molecules were estimated at electron energies higher than 20 eV.

  17. New Fission Cross Section Measurements using a Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Sadler, Michael

    2008-03-01

    A group of six universities (ACU, California Polytechnic, Colorado School of Mines, Georgia Institute of Technology, Ohio, and Oregon State) and three national laboratories (Los Alamos, Lawrence Livermore, and Idaho) have undertaken the task of building a Time Projection Chamber (TPC) to measure the fission cross sections needed for the next generation of nuclear reactors. The fission TPC concept will be presented, and why we think we can improve on 50 years of fission study.

  18. Cross-section data for selected Puerto Rico streams

    USGS Publications Warehouse

    Colon-Dieppa, Eloy; Gonzalez, Ralph

    1978-01-01

    The data presented are for delineating the inundation which could be expected by floods of selected magnitudes in Puerto Rico. These cross section data can be used in Flood Insurance Administration studies and in other studies related to the planning, development, and management of flood plains. The data were collected by the Caribbean District of the Water Resources Division of the U.S. Geological Survey in cooperation with the Puerto Rico Department of Natural Resources. (Woodard-USGS)

  19. Radar Cross Section (RCS) Simulation for Wind Turbines

    DTIC Science & Technology

    2013-06-01

    research, some basic scattering characteristics of wind turbines are discussed. Several computational methods of RCS prediction are examined, citing...a wind turbine and assess its effect on the performance of radar and communication systems. In this research, some basic scattering characteristics ... characteristics of wind turbines. The radar cross section (RCS) is a parameter that is used to estimate the effect of a wind turbine on a system’s

  20. Humeral cross-sectional shape in suspensory primates and sloths.

    PubMed

    Patel, Biren A; Ruff, Christopher B; Simons, Erin L R; Organ, Jason M

    2013-04-01

    Studies on the cross-sectional geometry of long bones in African apes have documented that shape ratios derived from second moments of area about principle axes (e.g., Imax /Imin ) are often correlated with habitual locomotor behaviors. For example, humeral cross-sections tend to appear more circular in more arboreal and forelimb suspensory chimpanzees compared with terrestrial quadrupedal gorillas. These data support the hypothesis that cross-sections that are more circular in shape are adapted for multidirectional loading regimes and bending moments encountered when using acrobatic locomotor behaviors. Whether a more circular humerus reflects greater use of forelimb suspension in other primates and nonprimate mammals is unknown. In this study, cross-sections at or near midshaft of the humerus were obtained from anthropoid primates that differ in their use of forelimb suspension, as well as from two genera of suspensory sloths. Imax /Imin ratios were compared within and between groups, and correlations were made with behavioral data. In broad comparisons, observed differences in morphology follow predicted patterns. Humeri of suspensory sloths are circular. Humeri of the more suspensory hominoids tend to be more circular than those of quadrupedal taxa. Humeri of the suspensory atelines are similar to hominoids, while those of Cebus are more like nonsuspensory cercopithecoids. There is, however, considerable overlap between taxa and within finer comparisons variation between species are not in the predicted direction. Thus, although Imax /Imin ratios of the humerus are informative for characterizing generalized locomotor modes (i.e., forelimb suspensory vs. quadrupedal), additional structural information is needed for more fine-grained assessments of locomotion.