Curvature terms in D-brane actions and their M-theory origin

We derive the complete $(curvature)^2$ terms of effective D-brane actions, for arbitrary ambient geometries and world-volume embeddings, at lowest order (disk-level) in the string-loop expansion. These terms reproduce the $o(\alpha'^2)$ corrections to string scattering amplitudes, and are consistent with duality conjectures. In the particular case of the D3-brane with trivial normal bundle, considerations of $SL(2,\mathbb{Z})$ invariance lead to a complete sum of D-instanton corrections for both the parity-conserving and the parity-violating parts of the effective action. These corrections are required for the cancellation of the modular anomalies of massless modes, and are consistent with the absence of chiral anomalies in the intersection domain of pairs of D-branes. We also show that the parity-conserving part of the non-perturbative R^2 action follows from a one-loop quantum calculation in the six-dimensional world-volume of the M5-brane compactified on a two-torus.Comment: tex file, 31 pages, uses harvmac. Some rewriting of section 2, conclusions and appendix B, in particular in what concerns the discussion of seven-branes in the conclusions and the structure of $\alpha'^2$ terms in appendix B. Other minor corrections plus added reference

CFD Mixing Analysis of Jets Injected from Straight and Slanted Slots into Confined Crossflow in Rectangular Ducts

A CFD study was performed to analyze the mixing potential of opposed rows of staggered jets injected into confined crossflow in a rectangular duct. Three jet configurations were numerically tested: (1) straight (0 deg) slots; (2) perpendicular slanted (45 deg) slots angled in opposite directions on top and bottom walls; and (3) parallel slanted (45 deg) slots angled in the same direction on top and bottom walls. All three configurations were tested at slot spacing-to-duct height ratios (S/H) of 0.5, 0.75, and 1.0; a jet-to-mainstream momentum flux ratio (J) of 100; and a jet-to-mainstream mass flow ratio of 0.383. Each configuration had its best mixing performance at S/H of 0.75. Asymmetric flow patterns were expected and predicted for all slanted slot configurations. The parallel slanted slot configuration was the best overall configuration at x/H of 1.0 for S/H of 0.75

CFD mixing analysis of axially opposed rows of jets injected into confined crossflow

A computational fluid dynamics (CFD) parametric study was performed to analyze axially opposed rows of jets mixing with crossflow in a rectangular duct. Isothermal analysis was conducted to determine the influence of lateral geometric arrangement on mixing. Two lateral arrangements were analyzed: (1) inline (jets' centerlines aligned with each other on top and bottom walls), and (2) staggered (jets' centerlines offset with each other on top and bottom walls). For a jet-to-mainstream mass flow ratio (MR) of 2.0, design parameters were systematically varied for jet-to-mainstream momentum-flux ratios (J) between 16 and 64 and orifice spacing-to-duct height ratios (S/H) between 0.125 and 1.5. Comparisons were made between geometries optimized for S/H at a specified J. Inline configurations had a unique spacing for best mixing at a specified J. In contrast, staggered configurations had two 'good mixing' spacings for each J, one corresponding to optimum inline spacing and the other corresponding to optimum non-impinging jet spacing. The inline configurations, due to their smaller orifice size at optimum S/H, produced better initial mixing characteristics. At downstream locations (e.g. x/H of 1.5), the optimum non-impinging staggered configuration produced better mixing than the optimum inline configuration for J of 64; the opposite results were observed for J of 16. Increasing J resulted in better mixing characteristics if each configuration was optimized with respect to orifice spacing. Mixing performance was shown to be similar to results from previous dilution jet mixing investigations (MR less than 0.5)

Sistem Pendukung Keputusan Penilaian Kinerja Karyawan Berbasis Spencer dengan Metode Analitycal Hierarcy Process (Studi Kasus Baperjakat Universitas Trunojoyo Madura)

Dalam penentuan karyawan berprestasi pada bagian kepegawaian khususnya Universitas Trunojoyo (BAPERJAKAT) terdapat beberapa faktor yang menjadi penilaian. Penelitian ini melakukan penilaian kinerja karyawan dengan berbasis Competencies for Executive Leadership Development yakni pengetahuan tentang pekerjaan, kreativitas, perencanaan, pelaksanaan instruksi, pelaksanaan deskripsi tugas, kualitas kerja, kerja sama dan sikap terhadap karyawan lain, inisiatif, kehandalan, kehadiran, sikap pekerjaan, keuletan, dan kejujuran. Kompetensi tersebut dirangkum oleh spencer menjadi standart penilaian yang akan dibandingkan dengan penilaian DP3 untuk membangun sebuah sistem pendukung keputusan yang mempunyai kemampuan analisa pemilihan karyawan berprestasi. Metode yang digunakan untuk perhitungan pembobotan menggunakan metode Analytic Hierarchy Process (AHP), di mana masing-masing kriteria dihitung berdasarkan uji konsistensi untuk dijadikan pembobotan pada setiap karyawan. Sedangkan hasilnya berupa perangkingan untuk pengambil keputusan yang terkait dengan masalah pemilihan karyawan berprestasi, sehingga akan didapatkan karyawan yang paling layak diberi rekomendasi ke jenjang selanjutnya. Untuk mengambil suatu keputusan tergantung dari kuota yang ada dan urutan tertinggi dari perangkingan sebagai prioritas yang paling diutamakan. Pada perhitungan menggunakan kriteria kompetensi Spencer menghasilkan skor 3.1 dan AHP 2.94 . dan Metode Spencer merupakan metode penilaian yang terbaik karena mempunyai rentang pembobotan yang kecil karena kriteria lebih banyak

Cost effective flat plate photovoltaic modules using light trapping

Work in optical trapping in 'thick films' is described to form a design guide for photovoltaic engineers. A thick optical film can trap light by diffusive reflection and total internal reflection. Light can be propagated reasonably long distances compared with layer thicknesses by this technique. This makes it possible to conduct light from inter-cell and intra-cell areas now not used in photovoltaic modules onto active cell areas

The state of agricultural credit in New Zealand

In this paper the subject of agricultural credit has been subdivided into three sections covering background, borrowing, and lending. The background covers some of the changes in the New Zealand economy and government policies which have affected both borrowers and lenders in the agricultural sector, and consequently the amount and form of credit used. The section on borrowing (Section 3) examines the present credit needs of farmers, in particular the apparent trends towards increased equity and greater difficulty in servicing debt. The lending section (Section 4) examines the roles of government and private lending institutions in the field of agricultural credit and changes in the amount and form of credit available

A review of agricultural credit in New Zealand

The following discussion of the agricultural credit market encompasses agriculture in its wider sense. Because most of the available information and data on agricultural credit is concerned with traditional forms of pastoral farming (sheep, beef and dairy) the discussion relates primarily to those sectors. However, the growing importance of other sectors such as horticulture, grain cropping and deer farming is recognised and where possible their credit situation is also considered. The purpose of the paper is to update previous research by the Agricultural Economics Research Unit into the financing of the agriculture industry. In the past the agricultural credit situation has been relatively stable. Because of its large contribution to exports, agriculture (pastoral agriculture in particular) received considerable support from Government in the form of policies aimed at maintaining a steady flow of investment. Credit assistance was one of the cornerstones of these policies. In 1982 the Government began to change its stance. In the Budget of that year interest payments and certain development ceased to be tax deductible where the farm property was sold within 10 years of purchase. Although this steadied inflation in land prices, long term investors particularly pastoral farm investors still enjoyed considerable advantages over investors wishing to borrow capital for diversification into or expansion of enterprises which were capable of better returns on investment. It was not until late 1984 that a wide range of policies were introduced to remove these advantages and promote greater equity between enterprises and industries requiring capital for restructuring or expansion. As a result some of the conclusions reached in Discussion Papers on agricultural and horticultural credit published by the Unit as recently as April and October 1984 have been quickly overtaken by economic events and need updating. This paper begins with a background of trends in the New Zealand economy and then in chronological order details recent changes in Government Policy. This is followed by a discussion of the implications of these changes for the financing of agriculture. Finally the present state of the agricultural credit market is discussed and some conclusions are drawn. The discussion is based on a variety of sources including MAF, Reserve Bank, Treasury, AERU and private economic reports and data. A considerable part of the material was also obtained from personal correspondence and interviews with people directly involved in the finance industry. The views expressed are, of course those of the authors