Measurements of the Influence of Integral Length Scale on Stagnation Region Heat Transfer

The purpose of the present work was twofold: first, to determine if a length scale existed that would cause the greatest augmentation in stagnation region heat transfer for a given turbulence intensity and second, to develop a prediction tool for stagnation heat transfer in the presence of free stream turbulence. Toward this end, a model with a circular leading edge was fabricated with heat transfer gages in the stagnation region. The model was qualified in a low turbulence wind tunnel by comparing measurements with Frossling's solution for stagnation region heat transfer in a laminar free stream. Five turbulence generating grids were fabricated; four were square mesh, biplane grids made from square bars. Each had identical mesh to bar width ratio but different bar widths. The fifth grid was an array of fine parallel wires that were perpendicular to the axis of the cylindrical leading edge. Turbulence intensity and integral length scale were measured as a function of distance from the grids. Stagnation region heat transfer was measured at various distances downstream of each grid. Data were taken at cylinder Reynolds numbers ranging from 42,000 to 193,000. Turbulence intensities were in the range 1.1 to 15.9 percent while the ratio of integral length scale to cylinder diameter ranged from 0.05 to 0.30. Stagnation region heat transfer augmentation increased with decreasing length scale. An optimum scale was not found. A correlation was developed that fit heat transfer data for the square bar grids to within ±4%. The data from the array of wires were not predicted by the correlation; augmentation was higher for this case indicating that the degree of isotropy in the turbulent flow field has a large effect on stagnation heat transfer. The data of other researchers are also compared with the correlation

Public health insurance and entry into self-employment

We estimate the impact of a differential treatment of paid employees versus self-employed workers in a public health insurance system on the entry rate into entrepreneurship. In Germany, the public health insurance system is mandatory for most paid employees, but not for the selfemployed, who usually buy private health insurance. Private health insurance contributions are relatively low for the young and healthy, and until 2013 also for males, but less attractive at the other ends of these dimensions and if membership in the public health insurance allows other family members to be covered by contribution-free family insurance. Therefore, the health insurance system can create incentives or disincentives to starting up a business depending on the family’s situation and health. We estimate a discrete time hazard rate model of entrepreneurial entry based on representative household panel data for Germany, which include personal health information, and we account for non- random sample selection. We estimate that an increase in the health insurance cost differential between self-employed workers and paid employees by 100 euro per month decreases the annual probability of entry into selfemployment by 0.38 percentage points, i.e. about a third of the average annual entry rate. The results show that the phenomenon of entrepreneurship lock, which an emerging literature describes for the system of employer provided health insurance in the USA, can also occur in a public health insurance system. Therefore, entrepreneurial activity should be taken into account when discussing potential health care reforms, not only in the USA and in Germany

Flavonoid profiling and transcriptome analysis reveals new gene–metabolite correlations in tubers of Solanum tuberosum L.

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns associated with the accumulation of purple tuber anthocyanins. The advanced potato selections, CO97216-3P/PW and CO97227-2P/PW, developed by conventional breeding procedures, produced tubers with incomplete expression of tuber flesh pigmentation. This feature permits sampling pigmented and non-pigmented tissues from the same tubers, in essence, isolating the factors responsible for pigmentation from confounding genetic, environmental, and developmental effects. An examination of the transcriptome, coupled with metabolite data from purple pigmented sectors and from non-pigmented sectors of the same tuber, was undertaken to identify these genes whose expression correlated with elevated or altered polyphenol composition. Combined with a similar study using eight other conventional cultivars and advanced selections with different pigmentation, it was possible to produce a refined list of only 27 genes that were consistently differentially expressed in purple tuber tissues compared with white. Within this list are several new candidate genes that are likely to impact on tuber anthocyanin accumulation, including a gene encoding a novel single domain MYB transcription factor

Atlantic City Site Report

The Atlantic City borehole was the second site drilled as part of the New Jersey coastal plain drilling project, Leg 150X. It focused on middle middle Miocene to Oligocene "Icehouse" and middle-upper Eocene "Doubthouse" sequences known from previous rotary and cable tool wells. Recovery was not as good as at Island Beach (60% vs. 87%) because of hole stability problems; however, recovery was excellent for most of the critical lower-middle Miocene interval (390-937 ft; 81%). The surficial Cape May Formation (uppermost Pleistocene-Holocene; 123 ft thick) contains nearshore gravelly sand and clay at the top and fluvial deposits at the base that apparently correlate with the Cape May Formation at Island Beach. The ?middle Miocene Cohansey Formation (96 ft thick) sand and sandy clay represents fluvial deposits not present at Island Beach. The ages of both units are uncertain. Recovery of the uppermost part of the 706-ft-thick Kirkwood Formation was poor (no recovery from 293 to 390 ft), but recovery for the Kirkwood between 390 and 937 ft was excellent. The sand, silts, and clay facies expressed in the Kirkwood Formation at Atlantic City represent diverse fluvial, nearshore, and neritic (including prodelta) environments. Several upward-coarsening sequences can be recognized on the basis of lithofacies breaks, gamma-log changes, and hiatuses, corresponding with confining units at the base and aquifer units at the top. These lithostratigraphic and geohydrologic units correspond with similar units at Island Beach, and we suggest that they correlate. Numerous shell beds in the Atlantic City borehole allow preliminary dating of these sequences with Sr-isotopic stratigraphy, including the middle middle Miocene Kirkwood 3 sequence (13.3-13.5 Ma; from at least 401.7 to at least 470 ft), the upper lower Miocene Kirkwood 2 sequence 17.0 17.9 Ma; 512-666 ft), and the uppermost Oligocene to lower Miocene Kirkwood 1 sequence (20.3- 25.8 Ma; 666-937 ft). The Kirkwood 1 sequence may be divided into several additional sequences that have dramatic shell beds at their base and distinct ages determined by Sr isotopes: 20.3-21.9 Ma, 23.6-23.7 Ma, and -25.8 Ma. A sharp lithologic and gamma-log break at 741 ft may indicate another sequence boundary between 20.3 and 20.8 Ma, although Sr-isotopic resolution is not sufficient to document this hiatus unequivocally. The upper Eocene-Oligocene may be divided further into 3 sequences based on lithologic and gamma log changes that were dated with Sr isotopes: upper Oligocene (27.4-28.7 Ma), lower Oligocene (-33.4 Ma), and upper Eocene (36.6-37.7 Ma). Biostratigraphy is consistent with the Sr-isotopic ages and indicates additional lower upper Eocene and upper middle Eocene sequences. The systems tracts are generally well developed for these middle Eocene through middle Miocene sequences, with a basal shell or glauconite sand at the base and sands at the top. Further biostratigraphic and Sr-isotopic studies should refine the ages of the sequences, whereas lithostratigraphic and benthic foraminifer biofacies studies should reveal details of the depositional environments and systems tracts of these well-developed sequences