An experimental investigation of natural convection heat transfer from an array of uniformly heated vertical cylinders to mercury

An experimental investigation was conducted for natural convection heat transfer in an array of uniformly heated vertical cylinders in mercury. The test section consisted of seven electrically heated cylinders of 1.365 inch diameter and 3.825 inch heated length arranged in an equilateral triangular pattern. In order to preclude side flow effects, each seven pin bundle was surrounded by an enclosure tube with unheated half cylinders attached to the tube. Temperatures were measured with a stretched wire thermocouple probe which was designed to minimize flow disturbance effects. Four geometries were studied: the single vertical cylinder (P/D = ∞), and three bundle spacings, P/D = 1.5, 1.3, and 1.1, where P/D is the pitch-to-diameter ratio. The heat transfer results are presented in terms of the local Nusselt number and local modified Grashof number with the range on the Grashof number being 10⁵ < Gr[superscript *][subscript x] < 10¹⁰. The stretched wire probe results for the single cylinder are in agreement with those taken with an L-shaped probe and with previous experimental work. The bundle results were found to depend parametrically on both the heat flux and cylinder spacing. For the range investigated, the spacing effect was found to be much more significant than that of heat flux. The heat transfer results were found to depend significantly on circumferential position for P/D = 1.1, however circumferential dependence for the wider bundles was negligible. Rod-average correlations for the four geometries are also presented. The characteristics of the fluid temperature field were also studied. The trends observed in the mean temperature profiles for the various conditions are in agreement with those expected for this confined flow situation. In addition, fluctuations in the fluid temperatures were encountered and recorded. The trends shown by these disturbances are similar to those found for the previously studied vertical channel. The fluctuations were of largest amplitude for P/D = 1. 5, while those for P/D = 1.3 were slightly less severe, and those for the single cylinder and P/D = 1. 1 were negligible. The flow regimes thought to be encountered were the unstable laminar regime for P/D = 1.5 and 1.3, and the stable laminar one for the single cylinder and P/D = 1.1

Evaluation of Rapid Syphilis Testing Using the Syphilis Health Check in Florida, 2015–2016

The Syphilis Health Check (SHC) had low estimated specificity (91.5%) in one Florida county. We investigated use of SHC by a range of Florida publicly-funded programs between 2015 and 2016 to estimate specificity, positive predictive value (PPV), field staff acceptance, and impacts on programmatic outcomes. All reported SHC results were extracted from routinely collected program data. Field staff were surveyed about SHC’s utility. Analyses investigated differences between SHC and traditional syphilis testing outcomes. Of 3,630 SHC results reported, 442 were reactive; 92 (20.8%) had prior diagnoses of syphilis; 7 (1.6%) had no further testing. Of the remaining 343; 158 (46.0%) were confirmed cases, 168 (49.0%) were considered false-positive, and 17 (5.0%) were not cases but not clearly false-positive. Estimated specificity of SHC was 95.0%. Overall, 48.5% of positives became confirmed cases (PPV). PPV varied according to prevalence of syphilis in populations tested. Staff (90%) thought SHC helped identify new cases but expressed concern regarding discordance between reactive SHC and lab-based testing. Programmatic outcomes assessment showed shorter time to treatment and increased numbers of partners tested for the SHC group; these enhanced outcomes may better mitigate the spread of syphilis compared to traditional syphilis testing alone, but more research is needed

Análisis y valoración del capital intelectual desarrollado por las maquiladoras del norte de Tamaulipas, México: el caso de Nuevo Laredo

Conocer la contribución que las Empresas extranjeras maquiladoras, ahora Industria Manufacturera, Maquiladora y de Servicios de Exportación (IMMEX) aportan a México. En la actualidad hay más de 5,000 empresas, generan 2´300,000 fuentes de trabajo directo, INEGI (2015). Aprovechando la integración económica y su situación geográfica del país continúan instalándose más. La IMMEX tiene su twin en el extranjero, por tal, un alto porcentaje de su producción se exporta. Son empresas globalizadas, favorecen así al país ingresando divisas. Para el caso de Nuevo Laredo, identificar el sector IMMEX que prodiga conocimiento, capacita y adiestramiento al personal, permitiendo así, conocer y manipular tecnología de última generación. La investigación y desarrollo propicia valor agregado, induce a innovar productos, las twins transfieren esa tecnología a su IMMEX. La competitiva y desarrollo se sustenta implantando procesos productivos y normas medio ambientales, ofreciendo seguridad dentro y fuera de la empresa, para identificase como Empresa Socialmente Responsable

Raman study of magnetic excitations and magneto-elastic coupling in alpha-SrCr2O4

Using Raman spectroscopy, we investigate the lattice phonons, magnetic excitations, and magneto-elastic coupling in the distorted triangular-lattice Heisenberg antiferromagnet alpha-SrCr2O4, which develops helical magnetic order below 43 K. Temperature dependent phonon spectra are compared to predictions from density functional theory calculations which allows us to assign the observed modes and identify weak effects arising from coupled lattice and magnetic degrees of freedom. Raman scattering associated with two-magnon excitations is observed at 20 meV and 40 meV. These energies are in general agreement with our ab-initio calculations of exchange interactions and earlier theoretical predictions of the two-magnon Raman response of triangular-lattice antiferromagnets. The temperature dependence of the two-magnon excitations indicates that spin correlations persist well above the N\'eel temperature

[2]共同利用研究(平成10年度)

Contains supplementary text, figures and movie description

Constructing a man-made c-type cytochrome maquette in vivo:electron transfer, oxygen transport and conversion to a photoactive light harvesting maquette

The successful use of man-made proteins to advance synthetic biology requires both the fabrication of functional artificial proteins in a living environment, and the ability of these proteins to interact productively with other proteins and substrates in that environment. Proteins made by the maquette method integrate sophisticated oxidoreductase function into evolutionarily naive, non-computationally designed protein constructs with sequences that are entirely unrelated to any natural protein. Nevertheless, we show here that we can efficiently interface with the natural cellular machinery that covalently incorporates heme into natural cytochromes c to produce in vivo an artificial c-type cytochrome maquette. Furthermore, this c-type cytochrome maquette is designed with a displaceable histidine heme ligand that opens to allow functional oxygen binding, the primary event in more sophisticated functions ranging from oxygen storage and transport to catalytic hydroxylation. To exploit the range of functions that comes from the freedom to bind a variety of redox cofactors within a single maquette framework, this c-type cytochrome maquette is designed with a second, non-heme C, tetrapyrrole binding site, enabling the construction of an elementary electron transport chain, and when the heme C iron is replaced with zinc to create a Zn porphyrin, a light-activatable artificial redox protein. The work we describe here represents a major advance in de novo protein design, offering a robust platform for new c-type heme based oxidoreductase designs and an equally important proof-of-principle that cofactor-equipped man-made proteins can be expressed in living cells, paving the way for constructing functionally useful man-made proteins in vivo

Illuminating hydrological processes at the soil-vegetation-atmosphere interface with water stable isotopes

Funded by DFG research project “From Catchments as Organised Systems to Models based on Functional Units” (FOR 1Peer reviewedPublisher PDFPublisher PD

Men Presenting With Sexual Thoughts of Children or Coercion: Flights of Fancy or Plans for Crime?

Introduction. There is limited evaluation of clinical and theoretical claims that sexual thoughts of children and coercing others facilitate sexual offending. The nature of these thoughts (what they contain) is also unknown. Aims. To examine the relationship between child/coercive sexual thoughts and sexual offending, and to determine the nature of these thoughts and any differences between sexual offending (SO), non-sexual offending (NSO) and non-offending (NO) men. Methods. In a cross-sectional computerized survey, anonymous qualitative and quantitative self-reported sexual thought and experience data were collected from 279 adult volunteers, comprising equal numbers of SO, NSO and NO men recruited from a medium-security UK prison and a community sample of 6081 men. Main Outcome Measures. Computerized Interview for Sexual Thoughts and Computerized Inventory of Sexual Experiences. Results. Three analytical approaches found child sexual thoughts were related to sexual offending; sexual thoughts with coercive themes were not. Latent class analyses identified three types of child sexual thought (primarily differentiated by interpersonal context: the reporting of own emotions, emotions of others or both) and four types of sexual thoughts of coercing others (chiefly discriminated by the other person’s response: no emotional states reported, consent, non-consent, mixed). Type of child sexual thought and participant group were not significantly related. Type of coercive sexual thought and group were marginally related; the consensual type was more common for the NO group, the non-consensual type more common for the SO group, than expected statistically. Conclusions. Child sexual thoughts are a risk factor for sexual offending and should be assessed by clinicians. Generally, sexual thoughts with coercive themes are not a risk factor, though thought type may be important (i.e. thoughts where the other person expresses an enduring lack of consent). Exploring the dynamic risk factors associated with each type of child/coercive thought may lead to more targeted treatment