The results of Soviet urbanization of Chita Oblast: structure, count and functional significance of urban settlements

  The article is dedicated to the results of urbanization of Chita Oblast in the late Soviet period. The author examines the established structure of urban settlements, count of cities and industrial townships, as well as their functional designation in the late 1980s. A brief characteristic of production base formed in the Soviet period (organizations, enterprises, etc.) is given by each city and large worker’s settlement. Calculation is conducted on separate demographic parameters of urbanization of the region: share of the urban population, share of the population of cities and industrial townships in the urban population, etc. The research leans on the official results of the All-Union Census of 1989, as well as the data from the official websites of urban settlements in Zabaykalsky Krai. It is underlined that by the end of the 1980s, on the territory of Chita Oblast was formed a broad and dispersed network of urban settlements, which for the most part scattered along Trans-Siberian Railway and southward towards the border with China. Trans-Baikal Railway and mining industry played the leading role in formation of majority of cities and workers’ settlements. The structure of urban settlements highlighted the capita of the region – Chita by demographical and functional aspects. However, nine more cities and five large townships with over 12,000 population and developed infrastructure, smoothed out the territorial imbalances in urbanization of the region.  

Mechanical Modeling and Continuous Process Improvement

Short design cycles for integrated circuits and packages drive the need for efficient problem solving and rapid results. Improved mechanical modeling software and increased computing power have taken these computation-heavy tools and made them versatile enough to support main-stream, real-time production needs. The utility of these tools has been significantly improved by simplified work flows to create detailed geometries and complex assemblies, improved mesh generation algorithms, and solve time reduction. Mechanical modeling software has a wide range of application which traditionally has been focused on design of large structures. Despite their general applicability, these tools have not been optimized for microelectronics in terms of absolute dimensions, fine structure count, and range of scale from the smallest to the largest component. Finding solutions to these problems pays off in fewer design cycles and significant process yield improvements. This paper will show multiple examples of process-induced stress, driven by material properties and manufacturing. They have been created using a variety of FEM tools, including ANSYS and Abaqus.

O6D.4 Association of occupational exposures with ex vivo functional immune response in workers handling carbon nanotubes and nanofibers

Animal toxicology studies suggest that workers exposed to carbon nanotubes or nanofibers (CNT/F) may experience pulmonary or systemic health effects; however, direct human evidence is lacking. Our study’s objective was to evaluate associations between CNT/F exposure and ex vivo responses of leukocytes challenged with secondary stimulants, adjusting for potential confounders, in a cross-sectional study. We measured multi-day exposure using CNT/F structure count (SC) and elemental carbon air concentrations among 102 U.S. workers. Demographic, lifestyle, and other occupational information was obtained via in-person interview. Workers’ whole blood was incubated for 18 hours with and without two microbial stimulants (lipopolysaccharide and staphylococcal enterotoxin type B) using TruCulture® technology to evaluate immune cell activity. Following incubation, collected supernatants were preserved and subsequently analyzed for cytokine and chemokine concentrations. The ratio of stimulant:null response for each protein was analyzed using multiple linear regression, principal components (PC) analysis, and Ingenuity® Pathway Analysis (IPA) to determine whether patterns of protein response were associated with CNT/F exposure. We found that CNT/F metrics (most consistently, the SC-based) were significantly (p<0.05) inversely associated with stimulant:null ratios of GM-CSF, IFN-γ, interleukin (IL)−2, IL-4, IL-5, IL-10, IL-17, and IL-23. CNT/F metrics were significantly inversely associated with PC1 (a weighted mean of most biomarkers that explained 25% of the variance in the set of protein ratios) and PC2 (a biomarker contrast that explained 14%). Among other occupational exposures, only solvent exposure was significantly (and was inversely) related to PC2. IPA suggested a CNT/F-associated generalized inhibition of all leukocyte responses when challenged with a secondary stimulus. We found that CNT/F exposure metrics were uniquely related to a pattern of reduced stimulant responses in challenged circulating leukocytes. This approach, if replicated in other exposed populations, may present a relatively sensitive method to evaluate human response to CNT/F or other occupational exposures.

On the number of Kekulé structures of fluoranthene congeners

The Kekul? structure count K of fluoranthene congeners is studied. It is shown that for such polycyclic conjugated ?-electron systems, either K = 0 or K ? 3. Moreover, for every t ? 3, there are infinitely many fluoranthene congeners having exactly t Kekul? structures. Three classes of Kekul?an fluoranthenes are distinguished: (i) ?0 - fluoranthene congeners in which neither the male nor the female benzenoid fragment has Kekul? structures, (ii) ?m - fluoranthene congeners in which the male benzenoid fragment has Kekul? structures, but the female does not, and (iii) ?fm - fluoranthene congeners in which both the male and female benzenoid fragments have Kekul? structures. Necessary and sufficient conditions are established for each class, ? = ?0, ?m, ?fm, such that for a given positive integer t, there exist fluoranthene congeners in ? with the property K = t.

Stability order of isomeric benzenoid hydrocarbons and Kekulé structure count

The commonly accepted opinion that the thermodynamic stability of isomeric benzenoid hydrocarbons (assessed by their total ?-electron energy and various resonance energies) increases with increasing number of Kekul? structures is shown to be violated in numerous cases. The smallest examples of such anomalous behavior are two hexacyclic pericondensed benzenoids of formula C24H14 and several pairs of heptacyclic catacondensed benzenoids of formula C30H18.

A Population Density Based Location Category System for Onshore Natural Gas Pipelines

The location class system used in current North American pipeline standards (ASME B31.8 and CSA Z662) is based on structure count included in a specified assessment area. Because the number of people occupying different structures can vary significantly, the population density can also vary significantly for the same location class. Given that the risk (in terms of human safety) imposed by onshore natural gas pipelines is directly proportional to the population density, the current location class system leads to a large variation in the risk level for pipelines with the same class. To achieve more risk consistent designs, a new location category system is proposed in this paper using actual population density data collected from over 19,000 km of gas pipelines in North America. The boundaries between different categories in the proposed system are directly based on population density rather than structure count. One of the key features of the new system is that it uses a separate category for pipelines in unpopulated areas, which are a significant majority of the pipelines included in the study. The implications of the new system are discussed by comparing the lengths of pipelines falling into each category with the lengths of pipelines falling into each location class for all the pipeline data analyzed.