For richer, for poorer: marriage and casualized sex in East African artisanal mining settlements

Migrants to Tanzania's artisanal gold mining sites seek mineral wealth, which is accompanied by high risks of occupational hazards, economic failure, AIDS and social censure from their home communities. Male miners in these settlements compete to attract newly arrived young women who are perceived to be diverting male material support from older women and children's economic survival. This article explores the dynamics of monogamy, polygamy and promiscuity in the context of rapid occupational change. It shows how a wide spectrum of productive and welfare outcomes is generated through sexual experimentation, which calls into question conventional concepts of prostitution, marriage and gender power relations

A low-voltage retarding-field Mott polarimeter for photocathode characterization

Nuclear physics experiments at Thomas Jefferson National Accelerator Facility's CEBAF rely on high polarization electron beams. We describe a recently commissioned system for prequalifying and studying photocathodes for CEBAF with a load-locked, low-voltage polarized electron source coupled to a compact retarding-field Mott polarimeter. The polarimeter uses simplified electrode structures and operates from 5 to 30 kV. The effective Sherman function for this device has been calibrated by comparison with the CEBAF 5 MeV Mott polarimeter. For elastic scattering from a thick gold target at 20 keV, the effective Sherman function is 0.201(5). Its maximum efficiency at 20 keV, defined as the detected count rate divided by the incident particle current, is 5.4(2) x 10-4, yielding a figure-of-merit, or analyzing power squared times efficiency, of 1.0(1) x 10-5. The operating parameters of this new polarimeter design are compared to previously published data for other compact Mott polarimeters of the retarding-field type.Comment: 9 figure

Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2 concentration resulted in incremental loss in IAS performance and revealed progressive degrees of “staining” upon testing. Adsorption of SO2 by the IAS necessitates upstream removal of SO2 prior to CO2 capture

Impact of cell wall encapsulation of almonds on in vitro duodenal lipolysis

Although almonds have a high lipid content, their consumption is associated with reduced risk of cardiovascular disease. One explanation for this paradox could be limited bioaccessibility of almond lipids due to the cell wall matrix acting as a physical barrier to digestion in the upper gastrointestinal tract. We aimed to measure the rate and extent of lipolysis in an in vitro duodenum digestion model, using raw and roasted almond materials with potentially different degrees of bioaccessibility. The results revealed that a decrease in particle size led to an increased rate and extent of lipolysis. Particle size had a crucial impact on lipid bioaccessibility, since it is an indicator of the proportion of ruptured cells in the almond tissue. Separated almond cells with intact cell walls showed the lowest levels of digestibility. This study underlines the importance of the cell wall for modulating lipid uptake and hence the positive health benefits underlying almond consumption

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U

The infrared imaging video bolometer (IRVB) measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 × 480 (1280 × 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm × 9 cm × 2 μm Pt foil. The foil is divided into 40 × 40 (64 × 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) μW/cm2 for a time resolution of 33 (20) ms. Synthetic images derived from Scrape Off Layer Plasma Simulation data using the IRVB geometry show peak signal levels ranging from ∼0.8 to ∼80 (∼0.36 to ∼26) mW/cm2

Species abundance distributions: moving beyond single prediction theories to integration within an ecological framework

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75247/1/j.1461-0248.2007.01094.x.pd

Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

Measurement of the Mass Splittings between the bbˉχb,J(1P)b\bar{b}\chi_{b,J}(1P) States

We present new measurements of photon energies and branching fractions for the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the chi_b states are determined from the measured radiative photon energies. The ratio of mass splittings between the chi_b substates, r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information on the nature of the bbbar confining potential. We find r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN