An integrality theorem of Grosshans over arbitrary base ring

We revisit a theorem of Grosshans and show that it holds over arbitrary commutative base ring $k$. One considers a split reductive group scheme $G$ acting on a $k$-algebra $A$ and leaving invariant a subalgebra $R$. If $R^U=A^U$ then the conclusion is that $A$ is integral over $R$.Comment: 5 pages; final versio

Analytic mode matching for a circular dissipative silencer containing mean flow and a perforated pipe

An analytic mode matching scheme that includes higher order modes is developed for a straight-through circular dissipative silencer. Uniform mean flow is added to the central airway and a concentric perforated screen separates the mean flow from a bulk reacting porous material. Transmission loss predictions are compared with experimental measurements and good agreement is demonstrated for three different silencers. Furthermore, it is demonstrated that, when mean flow is present, the axial kinematic matching condition should equate to that chosen for the radial kinematic boundary condition over the interface between the airway and the material. Accordingly, if the radial matching conditions are continuity of pressure and displacement, then the axial matching conditions should also be continuity of pressure and displacement, rather than pressure and velocity as previously thought. When a perforated screen is present the radial pressure condition changes, but the radial kinematic condition should always remain equivalent to that chosen for the axial kinematic matching condition; here, results indicate that continuity of displacement should be retained when a perforated screen is present

Measuring the information content of customer foreign exchange orders

This paper investigates whether customer order flow conveys information about future foreign exchange (FX) prices. We use a unique data set from a leading Australian commercial bank that records every FX trade made by the bank in the spot Australian dollar/US dollar market between 2005 and 2010. We find little evidence in support of a cointegrating relation or a statistically significant correlation between customer order flow and FX returns. However, consistent with the liquidity provision role of non-financial customers in Evans and Lyons ((2002) Order flow and exchange rate dynamics. Journal of Political Economy 110: 170–180), we find a statistically significant negative correlation between order flow from the diversified economic sector and FX returns. A dynamic analysis suggests that order flow has little or no price impact on FX returns. These results suggest that the non-financial customer order flow of a commercial bank does not carry information about FX prices

An extended range of stable-symmetric-conservative Flux Reconstruction correction functions

The Flux Reconstruction (FR) approach offers an efficient route to achieving high-order accuracy on unstructured grids. Additionally, FR offers a flexible framework for defining a range of numerical schemes in terms of so-called FR correction functions. Recently, a one-parameter family of FR correction functions were identified that lead to stable schemes for 1D linear advection problems. In this study we develop a procedure for identifying an extended range of stable, symmetric, and conservative FR correction functions. The procedure is applied to identify ranges of such correction functions for various orders of accuracy. Numerical experiments are undertaken, and the results found to be in agreement with the theoretical findings

From Large to Small Scales: Global Models of the ISM

We review large scale modelling of the ISM with emphasis on the importance to include the disk-halo-disk duty cycle and to use a dynamical refinement of the grid (in regions where steep variations of density and pressure occur) for a realistic modelling of the ISM. We also discuss the necessity of convergence of the simulation results by comparing 0.625, 1.25 and 2.5 pc resolution simulations and show that a minimum grid resolution of 1.25 pc is required for quantitatively reliable results, as there is a rapid convergence for Delta x \leq 1.1 pc.Comment: 10 pages, 8 figures that include 2 simulation images (in jpeg format) and 6 plots (4 in ps and 2 in jpeg formats), to appear in the proceedings of ``From Observations to Self-Consistent Modelling of the ISM in Galaxies'', Kluwe

RANCANG BANGUN KRAN WUDHU OTOMATIS MENGGUNAKAN LDR(LIGHT DEPENDENT RESISTOR)

RANCANG BANGUN KRAN WUDHU OTOMATIS MENGGUNAKAN LDR (LIGHT DEPENDENT RESISTOR)FAHRISAN FD1304005010044ABSTRAKBerkembangnya teknologi mendorong manusia untuk melakukan sesuatu dengan lebih cepat dan praktis, salah satunya adalah teknologi yang dapat dimanfaatkan untuk mempermudah pekerjaan manusia dan lebih efesien, baik dalam hal waktu, tenaga biaya dan lain-lain. Teknologi tersebut membantu pekerjaan manusia secara mudah dan otomatis. Salah satunya perancangan kran wudhu otomatis. Masalah yang sering timbul dalam proses pengambilan wudhu seringkali mengalami kelupaan pada saat menutup kran setelah selesai berwudhu, sehingga air terus menetes dan mengakibatkan pemborosan. Maka oleh karena itu solusi yang ditawarkan adalah dengan pembuatan sistem kran otomatis. Pengguna tidak perlu lagi untuk membuka tutup tuas kran air, dikarenakan system ini menggunakan sensor LDR yang mana jika sinar laser yang dipancarkan ke LDR terhalang maka rangkaian akan aktif dan kran akan terbuka otomatis. Dengan menerapkan metode kran air otomatis ini dapat diketahui bahwa metode ini dapat diterapkan untuk menciptakan otomatisasi pada kran dan juga penghematan air. Dengan begitu air tidak banyak terbuang yang menimbulkan pemborosan.Kata kunci : LDR, Relay, Selonoid valve atau Pomp

Is it possible to write a scientific paper in an African language?

Objective: To explore the ability of ChiShona to express the formal categories of reporting scientific information. This would guide and enable authors to write abstracts of their work for formal presentations or as appendices to publication.Design: Document analysis of selected Medical Journals in EnglishSetting: Medical Library, College of Health Sciences. University of Zimbabwe.Results: The vocabulary and terminology to structure a scientific report is available or can be constructed from available vocabulary.Conclusion: The writing or translating of an original research paper is technically demanding. Other forms of communicating scientific information are more flexible and may be used more readily to develop scientific text in ChiShona, at least in the beginning. This will probably be the case with other African languages

Analyse cognitive d’une politique publique : justice environnementale et « marchés ruraux » de bois-énergie

Madagascar élabore depuis 1999 une politique publique relative à l’énergie domestique expérimentée d’abord dans le cadre d’un  programme pilote financé par l’aide internationale. Les deux principaux objectifs de cette politique sont, d’une part, l’approvisionnement durable des populations urbaines à faible pouvoir d’achat en charbon de bois pour la cuisson et, d’autre part, de réduire la pauvreté des ménages ruraux par  des activités génératrices de revenus telles que l’exploitation et le commerce du charbon de bois dans le cadre d’une gestion durable des forêts. L’article est fondé sur les enquêtes de terrain de l’auteur et présente une analyse cognitive (c’est - à - dire social - constructiviste) de ce programme pilote qui débouche sur quatre principales conclusions. (i) L’inefficacité écologique des marchés ruraux n’est pas perçue comme un problème public tant que l’approvisionnement des villes en charbon au moindre coût est socialement tenu pour résolu efficacement et avec justesse. (ii) Le relativisme culturel de cette conception de la justice environnementale est « universalisable » en ce que l’impératif surplombant d’approvisionner les villes africaines en énergie domestique au moindre coût est également invoqué par les organismes de développement. (iii) Le programme analysé est un cas typique d’inversion normative où les solutions disponibles ont déterminé les manières d’identifier le problème. (iv) Le concept de marché rural de bois - énergie est un « cadre d’interprétation du monde » qui justifie les mesures à prendre en démontrant le lien avec le diagnostic empirique même si les populations et administrations destinataires en font d’autres interprétations.ABSTRACTThe article describes how the policy concept of ‘rural charcoal markets’ coined in the 1990s by French technical assistants in West Africa was implemented a decade later in Madagascar by a pilot project to experiment a nationwide policy of forest management for domestic energy. The main goals of this policy are to provide cheap and sustainable domestic energy sources to poor urban dwellers; and to reduce the poverty of rural households by promoting sustainable forest management including income generation through producing and marketing charcoal. The article is based on the author’s personal fieldwork and presents a cognitive (i.e., social constructivist) analysis of this policy program which leads up to four main conclusions. (i) The ecological inefficiency of rural markets is not considered a public problem as long as the task of providing cheap charcoal to urban dwellers is socially perceived to be effectively and equitably solved by parallel product chains. (ii) The cultural relativity of this conception of environmental justice is universal insofar as the overriding goal of providing cheap charcoal to urban dwellers is shared and invoked by international aid donors. (iii) The pilot project under study is a case of normative inversion where previously existing policy solutions determined the ways in which the public problem came to be identified. (iv) The concept of rural fuel - wood market is a cognitive framework for viewing the world, which justifies policy measures to be adopted by invoking factual information even when this cultural representation is not widely shared by targeted populations and administrations