Hydrogen Dispersion and Ventilation Effects in Enclosures under Different Release Conditions

Hydrogen is an explosive gas, which could create extremely hazardous conditions when released into an enclosure. Full-scale experiments of hydrogen release and dispersion in the confined space were conducted. The experiments were performed for hydrogen release outflow of 63 × 10−3 m3/s through a single nozzle and multi-point release way optionally. It was found that the hydrogen dispersion in an enclosure strongly depends on the gas release way. Significantly higher hydrogen stratification is observed in a single nozzle release than in the case of the multi-point release when the gas concentration becomes more uniform in the entire enclosure volume. The experimental results were confirmed on the basis of Froud number analysis. The CFD simulations realized with the FDS code by NIST allowed visualization of the experimental hydrogen dispersion phenomenon and confirmed that the varied distribution of hydrogen did not affect the effectiveness of the accidental mechanical ventilation system applied in the tested room.

A method for estimating neighborhood characterization in studies of the association with availability of sit-down restaurants and supermarkets

Background Although neighborhood-level access to food differs by sociodemographic factors, a majority of research on neighborhoods and food access has used a single construct of neighborhood context, such as income or race. Therefore, the many interrelated built environment and sociodemographic characteristics of neighborhoods obscure relationships between neighborhood factors and food access. Methods The objective of this study was to account for the many interrelated characteristics of food-related neighborhood environments and examine the association between neighborhood type and relative availability of sit-down restaurants and supermarkets. Using cluster analyses with multiple measures of neighborhood characteristics (e.g., population density, mix of land use, and sociodemographic factors) we identified six neighborhood types in 1993 in the Twin Cities Region, Minnesota. We then used mixed effects regression models to estimate differences in the relative availability of sit-down restaurants and supermarkets in 1993, 2001, and 2011 across the six neighborhood types. Results We defined six types of neighborhoods that existed in 1993, namely, urban core, inner city, urban, aging suburb, high-income suburb, and suburban edge. Between 1993 and 2011, inner city neighborhoods experienced a greater increase in the percent of sit-down restaurants compared with urban core, urban, and aging suburbs. Differences in the percent of sit-down restaurants between inner city and aging suburbs, high-income suburbs and suburban edge neighborhoods increased between 1993 and 2011. Similarly, aging suburb neighborhoods had a greater percent of supermarkets compared with urban and high-income suburb neighborhoods in 2001 and 2011, but not in 1993, suggesting a more varied distribution of food stores across neighborhoods over time. Thus, the classification of neighborhood type based on sociodemographic and built environment characteristics resulted in a complex and increasingly varied distribution of restaurants and food stores. Conclusions The temporal increase in the relative availability of sit-down restaurants in inner cities after accounting for all restaurants might be partly related to a higher proportion of residents who eat-away-from-home, which is associated with higher calorie and fat intake.

The Polarities and Hybridities of Arctic Cinemas

This chapter foregrounds alternative approaches to Canadian Arctic Cinemas, identifying and examining practices and aesthetics that emphasize the hybridized, situated, and local. The chapter highlights some of the most distinctive aspects of Canadian Arctic filmmaking traditions: the innovative use of technological forms, multiple and varied distribution practices, a continual return to processes of historical re-enactment, variegated documentary film practices, and the rise of Arctic Indigenous filmmaking. In alignment with many contemporary Canadian film historiographies, the chapter emphasizes the central importance of narrowcast, multimedia, documentary, video arts, and expanded cinema to the nation’s work, which is quite distinct from many aspects of American and European cinematic traditions and practices. The Arctic cinematic/moving image traditions and practices considered include participatory and documentary filmmaking, Inuit television, Indigenous filmmaking collectives such as Isuma and Arnait, le cinéma vécu, the re-release of archival works as acts of repatriation, multiscreen and expanded cinemas, and IMAX.

Variation in the clinical presentation of takotsubo cardiomyopathy in a non-referral hospital

The spectrum of clinical presentations of takotsubo cardiomyopathy is larger than once suspected. There are several pulmonary and neurological diseases that can aggravate leading to atypical takotsubo cardiomyopathy documented in a large collective of case reports from all all over the world. This varied distribution of patients’ presentations is illustrated by several cases. The spectrum of takotsubo cardiomyopathy can be enlarged in non-acute and non-cardiac diseases leading to an increase of this diagnosis in a large number of patients.

ESTUDO DE INCLUSÕES FLUIDAS EM VEIOS DE QUARTZO E CARBONATO (± SULFETOS-SULFOSSAIS) DO DEPÓSITO CARVOARIA VELHA, LINEAMENTO AURÍFERO CÓRREGO DO SÍTIO, SANTA BÁRBARA, QUADRILÁTERO FERRÍFERO, MG

O Lineamento Aurífero Córrego do Sítio corresponde a uma zona de cisalhamento dúctil com um trend NE-SW controlandoquatorze depósitos de ouro, no qual se inclui o depósito Carvoaria Velha. A mineralização de ouro se hospeda em rochas arqueanas dogreenstone belt Rio das Velhas, estas correspondem a filitos e xistos finos alterados a quartzo, carbonato e sericita. O estilo demineralização principal ocorre em veios de quartzo-carbonato-sulfetos (±sulfossais). Os tipos de veios são classificados como: Veios V1 –quartzo-ankerita-sulfetos-berthierita-ouro – são paralelos à principal foliação Sn e estão localmente mineralizados em ouro. Veios V2 –quartzo-ankerita-pirita – são veios desenvolvidos no plano de clivagem de crenulação Sn+1, extensionais e raramente mineralizados. VeiosV3 – quartzo-ankerita – são veios de preenchimento de fraturas Sn+3, geralmente não contêm sulfetos e sulfossais. Veios V4 – quartzocalcita– são veios restritos aos diques e sills metamáficos, são extensionais e sem orientação preferencial. Os minerais-minério sãoarsenopirita, pirita, berthierita e pirrotita. Microssonda eletrônica revela a presença de fases metálicas ricas em As, Sb e Co (boulangerita,tetraedrita, cobalita e ullmanita), que sobrecrescem aos minerais-minério. Dados de inclusões fluidas caracterizam fluido mineralizadorcom composição H2O–CO2±CH4–NaCl, com traços de N2, podendo conter outros cátions além de Na+, como Mg2+, Ca2+ e Fe2+. Estes fluidosteriam pelo menos dois estágio de evolução: i) fluido inicial aprisionado em quarto fumê, com salinidade moderada (~8.5% em peso deNaCl eq.) e temperatura mínima de 280±17oC; e ii) fluido tardio, representado por fluido aprisionado em quartzo recristalizado, menossalino (~4.6% em peso de NaCl eq.) e temperatura mínima de 315±33oC. Os dados obtidos correspondem a valores típicos de fluidometamórfico característico de depósitos tipo orogenic gold.Palavras-chave: mineralização aurifera, inclusões fluidas, Quadrilátero Ferrífero, alteração hidrotermal ABSTRACTFLUID INCLUSION STUDIES IN QUARTZ-CARBONATE(± SULFIDES-SULFOSALTS) VEINS FROM CARVOARIA VELHA DEPOSIT,CÓRREGO DO SÍTIO GOLD LINEAMENT, SANTA BÁRBARA, QUADRILÁTERO FERRÍFERO, MG. The Córrego do Sítio Lineament is defined as a16 km long, NE-SW trending ductile shear zone which controls fourteen deposits, one of them is Carvoaria Velha deposit. Themineralization is hosted in Archean rocks of Rio das Velhas greenstone belt, represented for carbonaceous phyllite and schists withcarbonate, sericite, sulphide-sulphosalt and silica alteration. The main gold mineralization styles at the Córrego do Sítio lineament arequartz-carbonate-sulphide±sulphosalts veins of varied distribution. They are classified as: V1 veins – quartz-ankerite-pyrite-berthierite-gold– parallel to the main regional foliation Sn, and usually mineralized in gold; V2 veins – quartz-ankerite-pyrite – developed at the crenulationcleavage Sn+1, extensional and rarely gold mineralized; V3 veins – quartz-ankerite – filling Sn+3 fractures, usually free of sulphides andsulphosalts; V4 veins – quartz-calcite – of restricted occurrence in metamafic dykes and sills; they crosscut the metasedimentary sequence,are extensional and display no preferential orientation. The most common sulphides in all vein types are arsenopyrite, pyrite andpyrrhotite. Microprobe studies show the presence of metallic phases rich in Sb, Pb and Co, such as stibnite, ullmanite, tetrahedrite, galena,cobaltite and, commonly overgrowing. Based on the microthermometric data, the hydrothermal fluid is interpreted to reflect at least twoevolved stages: i) an early fluid stage, trapped in smoky quartz, of moderate ~8.5 eq. wt% NaCl salinity, and minimal trapping temperatureof 280±17oC; and ii) a late-stage fluid trapped in recrystallized quartz with lower ~4.6 eq. wt% NaCl salinity, and a minimal trappingtemperature of 315±33oC. These values are typical of metamorphic fluid characteristic of orogenic gold deposits.Keywords: gold mineralization, fluid inclusions, Quadrilátero Ferrífero, hydrothermal alteration

Sociolinguistic Remarks on the Indo-Iranian *-ka-Suffix: A Marker of Colloquial Register

The widespread Indo-Iranian *-ka suffix (also widely distributed elsewhere in Indo-European) is generally characterized as a diminutive or deprecatory marker, shading into pleonastic meaninglessness. However, it is easier to account for its extremely varied distribution and diverse functions by interpreting it as a sociolinguistic marker of colloquial or informal speech. The explosive growth of the suffix in the "middle" period languages of both Iranian and Indo-Aryan results in part from the greater representation of vernacular speech in those languages, but also from the convenience of the suffix as a means of staving off word-final phonological erosion. The suffix is also associated with speech by and about women from the ancient period (Vedic Sanskrit and Avestan) onwards. is association results from the fact that women are typed as colloquial speakers throughout these texts, lacking access to high-register grammatical forms and styles, and therefore paying attention to women's speech in ancient texts may give us a window on the colloquial register that is otherwise unavailable to us in these elite products.

Multiple Sclerosis Clinical Trials: Part 1—Basic Considerations

ABSTRACT Clinical trials in neurology are difficult, complex, usually expensive, and fraught with pitfalls. Clinical trials in multiple sclerosis (MS) are particularly difficult because of the relapsing-remitting nature of the disease, the highly varied distribution of the lesions, and varied signs and symptoms. While the number and quality of MS clinical trials have increased enormously in recent years, they remain controversial and are subject to endless criticism. There is no shortage of individuals willing and eager to criticize clinical trials if they claim a positive result. Conversely, negative trials are rarely published1 and, when they are, they are rarely criticized even though some negative trials are equally deserving of criticism. No trial is perfect, and few scientific endeavors are subject to more rigorous review and criticism than clinical trials. This article—the first in a series—will discuss various aspects of planning, designing, and implementing a clinical trial. (Int J MS Care. 2001; 3(1): 6–12)