A finite element-analytical method for modeling a structure in an infinite fluid

A method is described from which the interaction of an elastic structure with an infinite acoustic fluid is determined. The displacements of the structure and the pressure field of the immediate surrounding fluid are modeled by finite elements, and the remaining pressure field of the infinite fluid region is given by an analytical expression. This method yields a frequency dependent boundary condition for the outer fluid boundary when applied to the frequency response of an elastic beam in contact with an acoustic fluid. The frequency response of the beam is determined using NASTRAN, and compares favorably to the exact solution which is also presented. The effect of the fluid on the response of the structure at low and high frequencies is due to added mass and damping characteristics, respectively

Developing agricultural businesses: Management accounting and the FADN System

In the current economic situation, the demand for creating and maintaining a competitive edge puts increasing pressure on business leaders. They should better manage their costs, plan more accurately and finance projects in a manner which best supports organizational efficiency and development of a good long-term strategy. All this makes it necessary to turn data into valuable information, to improve accountability within the company, to make costs more transparent, and to better support plans and decisions about the future of the company. Consistent use of management accounting can help entrepreneurs reach these goals, and is especially valuable to agricultural businesses due to the special characteristics of the sector. The study looks at the methods, fields and the level of sophistication in using management accounting in Hungarian agricultural businesses, as well as the attitude of business leaders. Second, it looks at experiences, observations and possibilities concerning the FADN system. Third, it explores the connections and correlation between the two systems. The research described in the paper confirmed that using the analysis generated from management accounting and FADN data in business management can make farms more profitable and more effective than their competitors. It was also confirmed that the information generated can effectively support decision-making and management processes. Regarding the application of management accounting in the agricultural sector it is important to mention its ties to the FADN. Research findings indicated that the pieces of information generated by operating and supporting the two systems are interrelated, and that the two systems have a synergistic effect on each other. Experience so far suggests that there are additional fields where using both systems together will be beneficial. These include the development of profitability indicators for farms holdings based on uniform principles, which, among others, could play an important role in allocating subsidies or granting bank loans. ------------------------------------ A jelenlegi gazdasági körülmények és a versenyképesség megteremtésének, megÅ‘rzésének feltételei között egyre nagyobb a nyomás a vállalatok vezetÅ‘in, hogy jobban menedzseljék a költségeiket, hogy pontosabban tervezzenek, és hogy a legmegfelelÅ‘bben finanszírozzák a beruházásokat a vállalati hatékonyság növelése, és a megfelelÅ‘ hosszú távú stratégia kialakítása érdekében. Ezek a tények teszik szükségessé az adatok értékes információvá alakítását, a vállalaton belüli mind nagyobb elszámolhatóságot, a költségek nagyobb átláthatóságát, a jövÅ‘re vonatkozó tervek és döntések komolyabb alátámaszthatóságát. Mindehhez segíti hozzá a vállalkozókat a vezetÅ‘i számvitel szisztematikus alkalmazása, amelynek szükségessége a mezÅ‘gazdasági vállalatok körében az ágazat speciális volta miatt kiemelkedÅ‘ jelentÅ‘séggel bír. A tanulmány a magyar mezÅ‘gazdasági vállalkozások körében vizsgálja egyrészt a vezetÅ‘i számvitel alkalmazásának fejlettségét, területeit, módszereit, a vállalkozások vezetÅ‘inek hozzáállását, másrészt a tesztüzemi rendszerrel kapcsolatos tapasztalatokat, megfigyeléseket, lehetÅ‘ségeket, harmadrészt a két rendszer kapcsolatát, összefüggéseit. Megállapítható a tanulmányban leírt kutatás eredményei alapján, hogy a vezetÅ‘i számvitel és a FADN adataiból generált elemzések vállalatirányításhoz való felhasználása által a gazdaságok eredményesebbé, hatékonyabbá válhatnak versenytársaikhoz képest, valamint hogy ezeknek az információknak döntés- és vezetéstámogató szerepe van. A vezetÅ‘i számvitel mezÅ‘gazdasági szektorban való alkalmazásával kapcsolatban fontos megemlíteni annak a FADN-nal való kapcsolatát. Összefüggés rajzolódik ki ugyanis a kutatás nyomán a két rendszer működtetése, kiszolgálása által létrejövÅ‘ információk között, továbbá megfigyelhetÅ‘ a két rendszer egymást támogató hatása is. Az eddigi tapasztalatok a fentieken túl elÅ‘re vetítik a két rendszer együttes alkalmazásának további jól kamatoztatható felhasználhatósági területeit, mint például a gazdaságok egységes elvekre épülÅ‘ eredményességi mutatóinak létrehozását, amely többek között a támogatások odaítélésében vagy banki hitelek elbírálásában játszhatnának fontos szerepet.management information systems, management accounting, agriculture, EU, Farm Accountancy Data Network, vezetÅ‘i információs rendszerek, vezetÅ‘i számvitel, mezÅ‘gazdaság, EU, tesztüzemi információs rendszer, Agribusiness, Agricultural Finance,

The breakdown flash of Silicon Avalance Photodiodes - backdoor for eavesdropper attacks?

Silicon avalanche photodiodes are the most sensitive photodetectors in the visible to near infrared region. However, when they are used for single photon detection in a Geiger mode, they are known to emit light on the controlled breakdown used to detect a photoelectron. This fluorescence light might have serious impacts on experimental applications like quantum cryptography or single-particle spectroscopy. We characterized the fluorescence behaviour of silicon avalanche photodiodes in the experimentally simple passive quenching configuration and discuss implications for their use in quantum cryptography systems.Comment: 9 pages, 6 figures, submitted to J. Mod. Optic

FEM/SINDA: Combining the strengths of NASTRAN, SINDA, I-DEAS, and PATRAN for thermal and structural analysis

This paper describes the interface/integration between FEM/SINDA, a general purpose geometry driven thermal analysis code, and the FEM software: I-DEAS, PATRAN, and NASTRAN. FEM/SINDA brings together the advantages of the finite element method to model arbitrary geometry and anisotropic materials and SINDA's finite difference capability to model thermal properties, loads, and boundary conditions that vary with time or temperature. I-DEAS and PATRAN thermal entities are directly supported since FEM/SINDA uses the nodes of the FEM model as the point at which the temperature is determined. Output from FEM/SINDA (as well as the FEM/SINDA input deck) can be used directly by NASTRAN for structural analysis

Analysis of bacterial and protozoan communities in an aquifer contaminated with monoaromatic hydrocarbons

Bacterial and protozoan communities were examined in three cores (A, B and C) from an aquifer located at an abandoned refinery near Hünxe, Germany. Cores were removed along a transect bordering a plume containing various monoaromatic hydrocarbons. Monoaromatic hydrocarbons could not be detected in the unsaturated zone in any core but were present in the saturated zones of core C (between 280 and 42 600 μmol kg−1 of core material [dry wt.]) and cores A and B (between 30 and 190 μmol kg−1 of core material [dry wt.]). Xylene isomers accounted for 50-70% of monoaromatic hydrocarbons in all cores. The number of DAPI-stained bacteria was found to increase from the low-contaminated cores A and B (approx. 0.1×108 cells and 0.2×108 cells g−1 of core material [dry wt.], respectively) to the high-contaminated core C (2.4×108 cells g−1 of core material [dry wt.]). The higher bacterial numbers in core C were found to coincide with a higher detection rate obtained by in situ hybridization using probe Eub338 to target the domain Bacteria (13-42% for core C as compared to 3-25% for cores A and B, respectively). Proteobacteria of the δ-subdivision (which includes many sulfate-reducing bacteria) were the most predominant of the groups investigated (7-15% of DAPI-stained bacteria) and were followed by Proteobacteria of the γ- and β-subdivisions (4% and 1% of DAPI-stained bacteria, respectively). The total numbers of protozoa and bacteria determined by direct counting occurred in a ratio of approx. 1:103, which was independent of depth or core examined. Most probable number analysis combined with a subsequent classification of the culturable protozoa revealed nanoflagellates as the major component of the protozoan community. Naked amoebae became increasingly more encysted with depth, except in the high-contaminated core C where vegetative trophozoites were present in the saturated zone. The co-occurrence of bacteria and protozoa in association with high concentrations of monoaromatic hydrocarbons suggests the involvement of trophic interactions in the process of biodegradatio

Tracing toluene-assimilating sulfate-reducing bacteria using 13C-incorporation in fatty acids and whole-cell hybridization

Polar lipid-derived fatty acids (PLFA) commonly found in sulfate-reducing bacteria were detected in high abundance in the sediment harvested from a monitoring well of a petroleum-hydrocarbon (PHC)-contaminated aquifer. Aquifer microcosms were incubated under sulfate-reducing conditions with [methyl-14C]toluene to determine the 14C-mass balances and with [methyl-13C]toluene to follow the flow of carbon from toluene into biomarker fatty acids. An aliquot was used to establish an aquifer-derived toluene-degrading sulfate-reducing consortium, which grew well in liquid medium. Whole-cell hybridization using 16S rRNA-targeted oligonucleotide probes specific for different phylogenetic levels within the sulfate-reducing bacteria was applied in order to characterize the sulfate-reducing populations in the original sediment, the aquifer microcosms, and the aquifer-derived consortium. In the aquifer microcosms, the 14C quantification revealed that 61.6% of the [methyl-14C]toluene was mineralized and 2.7% was assimilated. Following [methyl-13C]toluene depletion (<1 μM), the highest 13C-enrichment was found in PLFA 16:1ω5c. In addition, biomarker fatty acids characteristic for the genera Desulfobacter and Desulfobacula (cy17:0 and 10Me16:0) were also 13C-enriched, contrary to those of other sulfate-reducing genera, e.g. Desulfovibrio and Synthrophobacter (i17:1ω7c), Desulfobulbus and Desulforhabdus (15:1ω6c and 17:1ω6c). Although hybridization detection rates remained low, indicating low bacterial activities, 43% (aquifer sediment) and 30% (aquifer microcosm) of the total active bacteria belonged to the Desulfobacteriaceae thus supporting the PLFA-based results. Desulfobacter-species (42%), which belong to the Desulfobacteriaceae, dominated the community of the consortium. Our study showed that carbon stable isotope analysis in combination with whole-cell hybridization could link toluene degradation in aquifer microcosms to the metabolic activity of the Desulfobacter-like populations. These populations could play an important role in the clean up of aromatic PHC-contaminated aquifer

HUBUNGAN ANTARA KESEPIAN DENGAN INTERAKSI PARASOSIAL PADA PEREMPUAN DEWASA MUDA ANGGOTA FANSCLUB PRILLVERS SEMARANG

Penelitian ini bertujuan untuk mengetahui hubungan antara kesepian dan interaksi parasosial pada perempuan dewasa muda anggota fansclub Prillvers Semarang. Populasi dalam penelitian ini adalah perempuan dewasa muda anggota fansclub Prillvers Semarang dengan sampel berjumlah 61 orang. Metode pengambilan sampel menggunakan teknik simple random. Alat ukur yang digunakan adalah skala kesepian dan skala interaksi parasosial. Skala kesepian berjumlah 20 aitem dengan koefisien realibilitas data 0,811. Skala interaksi parasosial berjumlah 16 aitem dengan koefisien reliabitas data 0,533. Analisis data dalam penelitian ini menggunakan teknik korelasi Product Moment dari Pearson. Hasil uji hipotesis menunjukkan ada hubungan positif yang signifikan antara kesepian dengan interaksi parasosial pada perempuan dewasa muda anggota fansclub Prillvers Semarang dengan nilai korelasi rxysebesar 0,477 dan nilai Fhitung sebesar 13,979 dengan taraf signifikasi p=0,000 (pada p<0,01).Kata kunci: kesepian, interaksi parasosia

Phylogenetic analysis of a highly specific association between ectosymbiotic, sulfur-oxidizing bacteria and a marine nematode

The phylogenetic relationship of chemoautotrophic, sulfur-oxidizing, ectosymbiotic bacteria growing on a marine nematode, a Laxus sp. (formerly a Catanema sp.), to known endosymbionts and free-living bacteria was determined. Comparative 16S rRNA sequencing was used to investigate the unculturable nematode epibionts, and rRNA-targeted oligonucleotide hybridization probes were used to identify the ectosymbionts in situ. Both analyses revealed a remarkably specific and stable symbiosis. Unique hybridization of a specific probe to the ectosymbionts indicated that only one species of bacteria was present and growing on the cuticle of the nematode. Distance and parsimony methods used to infer phylogenetic trees both placed the nematode ectosymbionts at the base of a branch containing chemoautotrophic, sulfur-oxidizing endosymbionts of three bivalve families and of the tube worm Riftia pachyptila. The most closely related free-living bacteria were chemoautotrophic sulfur oxidizers belonging to the genus Thiomicrospira. Furthermore, our results suggested that a second, only distantly related group of thioautotrophic endosymbionts has as its deepest branch surface-colonizing bacteria belonging to the genus Thiothrix, some of which are capable of sulfur-oxidizing chemoautotrophic growth.Organismic and Evolutionary Biolog

Missing lithotroph identified as new planctomycete

With the increased use of chemical fertilizers in agriculture, many densely populated countries face environmental problems associated with high ammonia emissions. The process of anaerobic ammonia oxidation ('anammox') is one of the most innovative technological advances in the removal of ammonia nitrogen from waste water. This new process combines ammonia and nitrite directly into dinitrogen gas. Until now, bacteria capable of anaerobically oxidizing ammonia had never been found and were known as "lithotrophs missing from nature". Here we report the discovery of this missing lithotroph and its identification as a new, autotrophic member of the order Planctomycetales, one of the major distinct divisions of the Bacteria. The new planctomycete grows extremely slowly, dividing only once every two weeks. At present, it cannot be cultivated by conventional microbiological techniques. The identification of this bacterium as the one responsible for anaerobic oxidation of ammonia makes an important contribution to the problem of unculturability