Development of high efficiency solar cells on silicon web

Web base material is being improved with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). Carrier loss mechanisms in web silicon was investigated, techniques were developed to reduce carrier recombination in the web, and web cells were fabricated using effective surface passivation. The effect of stress on web cell performance was also investigated

Cluster density functional theory for lattice models based on the theory of Mobius functions

Rosenfeld's fundamental measure theory for lattice models is given a rigorous formulation in terms of the theory of Mobius functions of partially ordered sets. The free-energy density functional is expressed as an expansion in a finite set of lattice clusters. This set is endowed a partial order, so that the coefficients of the cluster expansion are connected to its Mobius function. Because of this, it is rigorously proven that a unique such expansion exists for any lattice model. The low-density analysis of the free-energy functional motivates a redefinition of the basic clusters (zero-dimensional cavities) which guarantees a correct zero-density limit of the pair and triplet direct correlation functions. This new definition extends Rosenfeld's theory to lattice model with any kind of short-range interaction (repulsive or attractive, hard or soft, one- or multi-component...). Finally, a proof is given that these functionals have a consistent dimensional reduction, i.e. the functional for dimension d' can be obtained from that for dimension d (d'<d) if the latter is evaluated at a density profile confined to a d'-dimensional subset.Comment: 21 pages, 2 figures, uses iopart.cls, as well as diagrams.sty (included

CP violation at colliders

The prospects of experimental detection of $CP$ violation at $e^+e^-$ and $pp/p\overline{p}$ colliders are reviewed. After a general discussion on the quantities which can measure $CP$ violation and on the implications of the $CPT$ theorem, various possibilities of measuring $CP$ violation arising outside the standard model are taken up. $CP$ violation in leptonic processes, especially polarization effects in $e^+e^-\rightarrow l^+l^-$ are discussed next. $CP$ violation in $t\overline{t}$ and $W^+W^-$ production and decay is also described. (Based on talk presented at the WHEPP3, Madras, January 1994).Comment: 20 pages, latex, no figures (only revision is the comment that the article is based on a talk presented at WHEPP3, Madras, January 1994

Фторидная технология получения титановых порошков

Обоснована необходимость разработки новой технологии переработки титансодержащих концентратов. Выполнено исследование процесса фторирования рутилового концентрата элементным фтором. Описаны процессы, протекающие при электролитическом получении титановых порошков во фторидных расплавах TiF4. Для отмывки от примесей катодного осадка предложено две технологии – в смеси неорганических кислот и безводным HF; показаны преимущества отмывки HF; содержание примесей в порошке титана, полученном отмывкой в безводном HF несколько ниже, чем при "кислотной" отмывке. При промышленном осуществлении процесса HF рециркулирует в схеме, обеспечивая экологическую безопасность и низкую себестоимость Ti.The brief review of industrial technologies of processing the titanium containing concentrates has been carried out. The research of the fluorination process of rutile concentrates with element fluorine was carried out. The processes occurring during the electrolysis of titanic powders from fluoride fusions, from TiF4, are described. In order to wash off impurities of cathode deposit, two techniques were proposed - in a mixture of inorganic acids and anhydrous HF; advantages of washing off with HF are shown; the impurity content in the titanium powder obtained by washing off in anhydrous HF is slightly lower than at "acid" washing off. In the industrial process implementation HF recycles tin a circuit that ensures environmental safety of production and low production cost of obtained Ti

Taming troubled teens: The social production of mental morbidity amongst young mothers in Pelotas, Brazil

Copyright @ 2011 Elsevier Ltd. This is a post-print version of the article. The published version of the article can be viewed at the link below.Explanations for the association between teen-childbearing and subsequent mental morbidity vary considerably, from those based on neurological theories of development to those investigating underlying social and economic determinants. Based on longitudinal epidemiological and ethnographic sub-studies of the 1982 Pelotas birth cohort study, this paper explores the hypothesis that teen childbearing and subsequent mental morbidity have become associated through the interplay of culture, society, and biology in situations where teen pregnancy has become a stigmatised object of scientific and public health attention. Results show that the effect of teen childbearing on subsequent mental morbidity remained significant in the multivariate analysis. Ethnographic analysis, together with epidemiological effect modification analyses, suggest that this association is partially accounted for by the fact that it is more pronounced amongst a specific subgroup of women of low socio-economic status who, being more politicised about societal injustice, were also more critically engaged with – and thus troubled by – the inequitable institutionalisation of life-cycle transitions. With time, these women became highly critical of the institutionalised identification of early childbearing as a key violation of life-cycle norms and the differential class-based application of scientific knowledge on its causes and consequences. Public health campaigns should consider how the age-based institutionalisation of developmental norms has enabled the stigmatisation of those identified as transgressors.The 1982 cohort study has been funded by The Wellcome Trust, the World Health Organisation, the PanAmerican Health Organisation, the European Union, the Programa Nacional para Centros de Excelência (PRONEX), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), the Brazilian Ministry of Health, and the Fundação de Amparo à Pesquisa do Rio Grande do Sul (Fapergs). D Béhague received support from a US National Science Foundation Doctoral Fellowship and a Postdoctoral Training Fellowship from The Wellcome Trust (Grant no. GR077175MA)

CP Violation Induced by Heavy Majorana Neutrinos in the Decays of Higgs Scalars into Top-Quark, W- and Z-Boson Pairs

We analyze the possibility of $CP$ violation induced by heavy Majorana neutrinos in the decays of the Higgs particle into top-quark, $W$- and $Z$-boson pairs. In the framework of various ``see-saw" models with interfamily mixings, we find that Majorana neutrinos may give rise to sizable $CP$-odd observables at the one-loop electroweak order. Numerical estimates of these $CP$-violating effects that may be detected in high-energy colliders are presented.Comment: 16 p. (1 Figure), LaTeX, MAD/PH/78

Higher Dimensional Wormhole Geometries with Compact Dimensions

This paper studies wormhole solutions to Einstein gravity with an arbitrary number of time dependent compact dimensions and a matter-vacuum boundary. A new gauge is utilized which is particularly suited for studies of the wormhole throat. The solutions possess arbitrary functions which allow for the description of infinitely many wormhole systems of this type and, at the stellar boundary, the matter field is smoothly joined to vacuum. It turns out that the classical vacuum structure differs considerably from the four dimensional theory and is therefore studied in detail. The presence of the vacuum-matter boundary and extra dimensions places interesting restrictions on the wormhole. For example, in the static case, the radial size of a weak energy condition (WEC) respecting throat is restricted by the extra dimensions. There is a critical dimension, D=5, where this restriction is eliminated. In the time dependent case, one \emph{cannot} respect the WEC at the throat as the time dependence actually tends the solution towards WEC violation. This differs considerably from the static case and the four dimensional case.Comment: 28 pages, 5 figures (quality reduced to reduce file size). Update includes added references and more detail regarding role extra dimensions play in wormhole analysis. Accepted for publication in Nuclear Phys.

Polarized Single Top Production at Leptonic Colliders from Broken R Parity Interactions Incorporating CP Violation

The contribution from the R parity violating interactions in the associated production of a top quark with a charm antiquark is examined for high energy leptonic colliders. We concentrate on the reactions associated with the semileptonic top decay. A set of characteristic dynamical distributions for the signal events is evaluated and the results contrasted against those from the standard model W-boson pair production background. Next, we turn to a study of a CP-odd observable, associated with the top spin, which leads to an asymmetry in the energy distribution of the emitted charged leptons for the pair of CP-conjugate final states, $b \bar l \nu \bar c$ and $\bar b l \bar \nu c$. A non vanishing asymmetry arises from a CP-odd phase, embedded in the R parity violating coupling constants, through interference terms between the R parity violating amplitudes at both the tree and loop levels.Comment: revtex file. 17 pages. 7 postscript figures. 1 table. The revised version includes an estimate of experimental uncertainties. Submitted to Phys. Rev.

Внедрение организационных инноваций в обустройстве инфраструктуры нефтегазовой отрасли

Инфраструктура занимает одну из важнейших должностей в организации, при грамотной инфраструктуре: организация несёт значительно меньше производственных потерь. Мы рассмотрим возможность внедрения инноваций в организационную деятельность в обустройстве инфраструктуры нефтегазовой отрасли.Infrastructure occupies one of the most important positions in the organization, with a competent infrastructure: the organization suffers significantly less production losses. We will consider the possibility of introducing innovations in organizational activities in arranging the infrastructure of the oil and gas industry