High-performance Si microwire photovoltaics

Crystalline Si wires, grown by the vapor–liquid–solid (VLS) process, have emerged as promising candidate materials for lowcost, thin-film photovoltaics. Here, we demonstrate VLS-grown Si microwires that have suitable electrical properties for high-performance photovoltaic applications, including long minority-carrier diffusion lengths (L_n » 30 µm) and low surface recombination velocities (S « 70 cm·s^(-1)). Single-wire radial p–n junction solar cells were fabricated with amorphous silicon and silicon nitride surface coatings, achieving up to 9.0% apparent photovoltaic efficiency, and exhibiting up to ~600 mV open-circuit voltage with over 80% fill factor. Projective single-wire measurements and optoelectronic simulations suggest that large-area Si wire-array solar cells have the potential to exceed 17% energy-conversion efficiency, offering a promising route toward cost-effective crystalline Si photovoltaics

Effects of Impurities in Random Sequential Adsorption on a One-Dimensional Substrate

We have solved the kinetics of random sequential adsorption of linear $k$-mers on a one-dimensional disordered substrate for the random sequential adsorption initial condition and for the random initial condition. The jamming limits $\theta(\infty, k', k)$ at fixed length of linear $k$-mers have a minimum point at a particular density of the linear $k'$-mers impurity for both cases. The coverage of the surface and the jamming limits are compared to the results for Monte Carlo simulation. The Monte Carlo results for the jamming limits are in good agreement with the analytical results. The continuum limits are derived from the analytical results on lattice substrates.Comment: 9 pages, latex, 1 figure not included, accepted in Phys. Rev.

Condensation and Clustering in the Driven Pair Exclusion Process

We investigate particle condensation in a driven pair exclusion process on one- and two- dimensional lattices under the periodic boundary condition. The model describes a biased hopping of particles subject to a pair exclusion constraint that each particle cannot stay at a same site with its pre-assigned partner. The pair exclusion causes a mesoscopic condensation characterized by the scaling of the condensate size $m_{\rm con}\sim N^\beta$ and the number of condensates $N_{\rm con}\sim N^\alpha$ with the total number of sites $N$. Those condensates are distributed randomly without hopping bias. We find that the hopping bias generates a spatial correlation among condensates so that a cluster of condensates appears. Especially, the cluster has an anisotropic shape in the two-dimensional system. The mesoscopic condensation and the clustering are studied by means of numerical simulations.Comment: 4 pages, 5 figure

Endometrial BCL6 Overexpression in Eutopic Endometrium of Women With Endometriosis

The objective of this study was to examine B-cell CLL/lymphoma 6 (BCL6) expression in human eutopic endometrium across the menstrual cycle in women with and without endometriosis and to establish a cutoff for future studies. This design was a series of case-control studies in tertiary University teaching hospitals. We examined BCL6 expression by messenger RNA and immunohistochemically in prospectively collected samples in both the proliferative (P) and the secretory phases. BCL6 is minimally increased in the mid-secretory phase of the menstrual cycle compared to the P phase in normal patients. BCL6 protein expression was significantly higher in the secretory phase of patients with endometriosis (n = 29) versus fertile controls without endometriosis at laparoscopy (n = 20; P < .0001). Normal fertile controls (n = 28) recruited for endometrial biopsy also had low levels of secretory phase BCL6 expression compared to women with unexplained infertility (UI; n = 119). A receiving-operator characteristic analysis of these data revealed an area under the curve of 94% (95% confidence interval 85%-100%; P < .0001) with an HSCORE cutoff of 1.4 to differentiate cases with and without endometriosis. Using this cutoff value, BCL6 was positive in 88% of cases with UI. Laparoscopic examination of a subset of 65 patients confirmed abnormalities in 98% of cases; 61 (93.8%) were found to have endometriosis, 3 (4.6%) with hydrosalpinx, and 1 (1.5%) with a normal pelvis. These data suggest that BCL6 is a promising candidate as a single diagnostic biomarker for detection of endometriosis in women with otherwise UI and may be associated with endometrial dysfunction, including progesterone resistanc

Symmetry energy of dense matter in holographic QCD

We study the nuclear symmetry energy of dense matter using holographic QCD. To this end, we consider two flavor branes with equal quark masses in a D4/D6/D6 model. We find that at all densities the symmetry energy monotonically increases. At small densities, it exhibits a power law behavior with the density, $E_{\rm sym} \sim \rho^{1/2}$.Comment: 9 pages, 3 figure

Rotation Curve of Galaxies by the Force Induced by Mass of Moving Particles

We suggest that there is a novel force which is generated by the mass of relatively moving particles. The new force which we named Mirinae Force is a counterpart of the magnetic force operating between electrically charged moving particles. Instead of using the conventional dark matter, we applied the mirinae force to a particular model system of the spiral galaxy in which most of the galaxy's mass is located within the central region where some portion of the inner mass is in revolving motion at a relativistic speed. The calculation yielded three important results that illustrate the existence of mirinae force and validate the proposed model: First, the mirinae force in this model explains why most of the matters in the galactic disk are in the circular motion which is similar to cycloid. Second, the mirinae force well explains not only the flat rotation curve but also the varied slope of the rotation curve observed in the spiral galaxies. Third, at the flat velocity of 220 Km/s, the inner mass of the Milky Way calculated by using the proposed model is 6.0\times10^11 M\odot, which is very close to 5.5\times10^11 M\odot (r <50 Kpc, including Leo I) estimated by using the latest kinematic information. This means that the mirinae force well takes the place of the dark matter of the Milky Way

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF)

The GMT-Consortium Large Earth Finder (G-CLEF) will be part of the first generation instrumentation suite for the Giant Magellan Telescope (GMT). G-CLEF is a general purpose echelle spectrograph operating in the optical passband with precision radial velocity (PRV) capability. The measurement precision goal of G-CLEF is 10 cm/sec; necessary for the detection of Earth analogues. This goal imposes challenging stability requirements on the optical mounts and spectrograph support structures especially when considering the instrument's operational environment. G-CLEF's accuracy will be influenced by changes in temperature and ambient air pressure, vibration, and micro gravity-vector variations caused by normal telescope motions. For these reasons we have chosen to enclose G-CLEF's spectrograph in a wellinsulated, vibration-isolated vacuum chamber in a gravity invariant location on GMT's azimuth platform. Additional design constraints posed by the GMT telescope include; a limited space envelope, a thermal leakage ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology, and budget are also significant design drivers. G-CLEF will complete its Critical Design phase in mid-2018. In this paper, we discuss the design of GCLEF's optical mounts and support structures including the choice of a low-CTE carbon-fiber optical bench. We discuss the vacuum chamber and vacuum systems. We discuss the design of G-CLEF's insulated enclosure and thermal control systems which simultaneously maintain the spectrograph at milli-Kelvin level stability and limit thermal leakage into the telescope dome. Also discussed are micro gravity-vector variations caused by normal telescope slewing, their uncorrected influence on image motion, and how they are dealt with in the design. We discuss G-CLEF's front-end assembly and fiber-feed system as well as other interface, integration and servicing challenges presented by the telescope, enclosure, and neighboring instrumentation. This work has been supported by the GMTO Corporation, a non-profit organization operated on behalf of an international consortium of universities and institutions: Arizona State University, Astronomy Australia Ltd, the Australian National University, the Carnegie Institution for Science, Harvard University, the Korea Astronomy and Space Science Institute, the São Paulo Research Foundation, the Smithsonian Institution, the University of Texas at Austin, Texas AM University, the University of Arizona, and the University of Chicago

Giant Cell Arteritis Presenting as Small Bowel Infarction

Giant cell arteritis predominantly affects cranial arteries and rarely involves other sites. We report a patient who presented with small bowel obstruction because of infarction from mesenteric giant cell arteritis. She had an unusual cause of her obstruction and a rare manifestation of giant cell arteritis. In spite of aggressive therapy with steroids, she died a month later because of multiple complications. We discuss the diagnosis and management of small bowel obstruction and differential diagnosis of vasculitis of the gastrointestinal tract. We were able to find 11 cases of bowel involvement with giant cell arteritis in the English literature. This case report illustrates that giant cell arteritis can be a cause of small bowel obstruction and bowel infarction. In the proper clinical setting, vasculitides need to be considered early in the differential diagnosis when therapy may be most effective