Numerical study of a nonlinear heat equation for plasma physics

This paper is devoted to the numerical approximation of a nonlinear temperature balance equation, which describes the heat evolution of a magnetically confined plasma in the edge region of a tokamak. The nonlinearity implies some numerical difficulties, in particular long time behavior, when solved with standard methods. An efficient numerical scheme is presented in this paper, based on a combination of a directional splitting scheme and the IMEX scheme introduced in [Filbet and Jin

PAH Emission Within Lyman Alpha Blobs

We present Spitzer observations of Lya Blobs (LAB) at z=2.38-3.09. The mid-infrared ratios (4.5/8um and 8/24um) indicate that ~60% of LAB infrared counterparts are cool, consistent with their infrared output being dominated by star formation and not active galactic nuclei (AGN). The rest have a substantial hot dust component that one would expect from an AGN or an extreme starburst. Comparing the mid-infrared to submillimeter fluxes (~850um or rest frame far infrared) also indicates a large percentage (~2/3) of the LAB counterparts have total bolometric energy output dominated by star formation, although the number of sources with sub-mm detections or meaningful upper limits remains small (~10). We obtained Infrared Spectrograph (IRS) spectra of 6 infrared-bright sources associated with LABs. Four of these sources have measurable polycyclic aromatic hydrocarbon (PAH) emission features, indicative of significant star formation, while the remaining two show a featureless continuum, indicative of infrared energy output completely dominated by an AGN. Two of the counterparts with PAHs are mixed sources, with PAH line-to-continuum ratios and PAH equivalent widths indicative of large energy contributions from both star formation and AGN. Most of the LAB infrared counterparts have large stellar masses, around 10^11 Mo. There is a weak trend of mass upper limit with the Lya luminosity of the host blob, particularly after the most likely AGN contaminants are removed. The range in likely energy sources for the LABs found in this and previous studies suggests that there is no single source of power that is producing all the known LABs.Comment: 34 pages, 5 figures, accepted by Ap

Polycyclic Aromatic Hydrocarbon Emission within Lyα Blobs

We present Spitzer observations of Lyα blobs (LABs) at z = 2.38-3.09. The mid-infrared ratios (4.5 μm/8 μm and 8 μm/24 μm) indicate that ~60% of LAB infrared counterparts are cool, consistent with their infrared output being dominated by star formation and not active galactic nuclei (AGNs). The rest have a substantial hot dust component that one would expect from an AGN or an extreme starburst. Comparing the mid-infrared to submillimeter fluxes (~850 μm or rest-frame far-infrared) also indicates that a large percentage (~2/3) of the LAB counterparts have total bolometric energy output dominated by star formation, although the number of sources with submillimeter detections or meaningful upper limits remains small (~10). We obtained Infrared Spectrograph (IRS) spectra of six infrared-bright sources associated with LABs. Four of these sources have measurable polycyclic aromatic hydrocarbon (PAH) emission features, indicative of significant star formation, while the remaining two show a featureless continuum, indicative of infrared energy output completely dominated by an AGN. Two of the counterparts with PAHs are mixed sources, with PAH line-to-continuum ratios and PAH equivalent widths indicative of large energy contributions from both star formation and AGN. Most of the LAB infrared counterparts have large stellar masses, around 10^(11) M_⊙. There is a weak trend of mass upper limit with the Lyα luminosity of the host blob, particularly after the most likely AGN contaminants are removed. The range in likely energy sources for the LABs found in this and previous studies suggests that there is no single source of power that is producing all the known LABs

Determinacion del modulo de elasticidad en hibridos de alamo a traves de metodo no destructivo en arboles en pie

77 p.El estudio del modulo de elasticidad se llevo a cabo en cinco híbridos de Álamo, pertenecientes a Compañía Agrícola y Forestal el Álamo, ubicada en la región del Maule. El modulo de elasticidad se midió en árboles en pie a través de un instrumento no destructivo, conocido como Rigidimetro, el cual permite obtener la deformación originada debido a la presión ejercida en el árbol, para así realizar el calculo del modulo de elasticidad. Los resultados mostraron diferencias significativas en el modulo de elasticidad de los híbridos, donde el híbrido I-488 alcanzo el modulo de elasticidad mas alto, mientras que el modulo de elasticidad mas bajo se presento en el híbrido I-63/51. El Rigidimetro permite realizar esquemas de selección entre los híbridos, a pesar de la variabilidad presenciada en las mediciones hechas en cada árbol. Frente a este ultimo punto, se hicieron algunas recomendaciones para mejorar la precisión del equipo

INDICADOR DE SUSTENTABILIDADE DASHBOARD: ANÁLISE DA SUSTENTABILIDADE DA PRODUÇÃO FAMILIAR DE FRUTAS NO MUNICÍPIO DE ITAPURANGA - GO

O objetivo do estudo foi analisar a sustentabilidade da produção tradicional e orgânica de frutas dos agricultores familiares do município de Itapuranga, por meio do indicador de sustentabilidade Dashboard. O principal problema é que o sistema de produção tradicional de frutas utilizado por estes agricultores estava sendo desenvolvido com o uso intensivo e inadequado de insumos químicos (fertilizantes e agrotóxicos) causando problemas de ordem social e econômica aos agricultores e impactos ao meio ambiente. De acordo com os resultados, conclui-se que: o sistema de fruticultura orgânica, mesmo se encontrando em fase inicial apresentou por meio do Indicador de Sustentabilidade Dashboard o Índice de Desenvolvimento Sustentável Global (IDS) com uma performance razoável. Isto indica que a implantação da fruticultura orgânica em Itapuranga, juntos aos agricultores familiares já dá sinais de que a fruticultura está sendo desenvolvida em bases mais sustentáveis. ---------------------------------------------The objective of this research went to analyze the sustainability of the traditional and organic production of the family farmers' of the municipal district of Itapuranga fruits, through the sustainability indicator Dashboard. The main problem is that the system of traditional production of fruits used by these farmers was being developed with the intensive and inadequate use of chemical (fertilizers and pesticides) inputs causing problems of social and economical order to the farmers and impacts to the environment. In agreement with the results, it is ended that: the system of organic horticulture, same meeting in initial phase presented through Sustentabilidade Dashboard Indicator the Index of Global (IDS) Maintainable Development with a reasonable performance. This indicates that the implantation of the organic horticulture in Itapuranga, together to the family farmers he/she already gives signs that the horticulture is being developed in more maintainable bases.Agricultura orgânica, Dashboard, Desenvolvimento Sustentável, Organic agriculture, Dashboard, Sustainable development, Environmental Economics and Policy, Farm Management,

OT Graduate Students’ Perceived Preparedness for Level II Fieldwork: Traditional, Nontraditional and Mixed Fieldwork I Experiences

This study explored the perceived level of preparedness of occupational therapy (OT) graduate students for entering Level II fieldwork after completing nontraditional, traditional, and mixed Level I fieldwork experiences. This mixed-methods exploratory study included an online 22-question survey that was delivered to Occupational Therapy Doctoral (OTD) and Master of Occupational Therapy (MOT) programs throughout the United States. Participants were selected through voluntary convenience response sampling. Students (N=145) self-reported their level of preparedness for Level II fieldwork experiences. The quantitative data collected in this study reflected a statistically significant difference between Level I fieldwork experience-related questions for the three groups, including traditional, nontraditional, and mixed traditional and nontraditional fieldwork experiences. More specifically, students that took traditional fieldwork experiences felt that traditional fieldwork positively contributed to their preparedness for Level II fieldwork compared to those who took nontraditional fieldwork or a mix of traditional and nontraditional fieldwork. The qualitative data, analyzed through thematic analysis, indicated that students felt a combination of nontraditional and traditional fieldwork provided the most significant benefit from Level I fieldwork experiences. Results suggest that most OT students preferred either a combination of nontraditional Level I fieldwork and traditional Level I fieldwork or solely traditional Level I fieldwork for increasing their perceived preparedness prior to starting Level II fieldwork. This study has implications for OTD and MOT fieldwork curriculum development and implications for addressing the needs of OT students to feel better prepared for Level II fieldwork

Campus Security and Safety Models: Statistical Empirical Analysis from a Ghanaian Tertiary Institution

All over the world security challenges faced by our traditional settlements is likewise in the university and college campuses. For this reason campus safety and security has become topical issue of research since parents are concerned about their wards and educational stakeholders risk losing loosing students because of crime and violence. With the influx of distance education students on the campus during the weekends and holidays, the issue of security becomes even more paramount. The current study model students’ perception of campus security personnel’s using  procedural fairness, security effectiveness and trust in security response construct while fear of crime as well as security corruption are used as predictor construct. PLS-SEM is the quantitative approach used to investigate effect security corruption and students fear of crime on security procedural fairness, security effectiveness and students’ trust in security. The study randomly selected 350 regular and distance students, however 327 returned questionnaires resulting to 93% response rate. The study revealed that students’ fear of crime and security corruption predicts 71.8% of students’ trust in security. Furthermore, security corruption and students fear of crime account for 31.2% of students’ perceived security personnel’s procedural fairness. Finally, the study found that security corruption and students fear of crime accounts for 39.5% of the variability in security personnel’s effectiveness. The study concluded that students’ fear of  crime positively affect their trust in campus security, however, the corruption on the part of campus security negatively affect students’ trust in campus security, security personnel’s procedural fairness and effectiveness. The authors recommend that training programmes should be put in place regularly to sensitise personnel’s on the effect of corruption on their integrity and profession. Keywords: Fear of crime, Security effectiveness, Security corruption, procedural fairness DOI: 10.7176/JEP/10-12-07 Publication date: April 30th 201