1,281 research outputs found

    Direct Laser Sintering of Borosilicate Glass

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    Despite the advantages that selective laser sintering (SLS) offers in terms of material availability, many materials have yet to be explored for feasibility and even fewer are available on a commercial basis. This paper presents initial investigations for one such material, borosilicate glass, which could be of particular interest to filter manufacturers because it presents an attractive alternative to the conventional, time-consuming way of producing filters of various porosity classes. Process results are presented including a determination of the optimal parameter window and the effect of processing parameters on the density and surface quality. The effects of thermal post-processing and the inclusion of an additive are also discussed.Mechanical Engineerin

    The Effects of Compost and Polyacrylamide Hydrogel on the Re-Vegetation of Eroded Southern Aspects in the Western Rangeland

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    MPG Ranch is a conservation-oriented organization in Montana’s Bitterroot valley. Since 2010, MPG has annually planted between 5,000 and 10,000 shrubs and trees with the goal of restoring native plant communities, beautifying the landscape, and providing habitat and forage for wildlife. Plant survival has been lowest on degraded south facing slopes, likely due to a combination of erosion and high solar radiation, which have left the soil with low nutrient content, soil moisture, and high soil temperatures. To resolve these issues, we partnered with MPG to test whether soil amendments can be used to increase plant establishment on degraded hillslopes. Soil amendments included a polyacrylamide hydrogel (Terra-sorb), compost, and Terra-sorb and compost combined. These amendments were tested on three different native shrub species: Cercocarpus ledifolius (curl leaf mountain mahogany), Juniperus scopulorum (Rocky Mountain juniper), and Purshia tridentata (antelope bitterbrush). We assessed the impact of these three soil amendments on plant growth, plant health/mortality rates, and soil chemical and physical properties. Overall results revealed few consistent patterns. Compost as a treatment resulted in the lowest levels of plant mortality whereas plants in the control plots suffered the highest. Plant growth was more dependent on the species in question rather than the amendment used. Mountain mahogany was the most successful in terms of growth both above and below ground with all living plants growing 0 – 1% throughout the course of the season. Our recommendation to MPG is that they continue to monitor these plants for multiple growing seasons in order to determine if they are more or less effective in the long run than what our experiment showed for short-term results

    Методика расчета КПД мехатронной системы генерирования электрической энергии постоянного тока

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    Предложена методика расчета активных потерь в элементах системы генерирования постоянного тока на базе магнитоэлектрического синхронного генератора и полупроводникового преобразователя. Особое внимание уделено анализу электрических потерь в синхронном генераторе: учитываются как искажения формы тока и напряжения синхронного генератора, так и изменение частоты вращения его вала, что позволяет повысить точность расчетов и качество проектирования отдельных элементов системы

    Screening of microbial communities associated with endive lettuce during postharvest processing on industrial scale

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    In this study, the composition of the microbial community on endive lettuce (Cichorium endivia) was evaluated during different postharvest processing steps. Microbial community structure was characterized by culture-dependent and culture-independent methods. Endive lettuce was sampled exemplarily at four different stages of processing (raw material, cut endive lettuce, washed endive lettuce, and spin-dried (ready to pack) endive lettuce) and analysed by plate count analysis using non-selective and selective agar plates with subsequent identification of bacteria colonies by matrix-assisted laser desorption/ionization time-of light mass spectrometry (MALDI-TOF MS). Additionally, terminal-restriction fragment length polymorphism (TRFLP) analysis and 16S rRNA gene nucleotide sequence analysis were conducted. The results revealed structural differences in the lettuce microbiomes during the different processing steps. The most predominant bacteria on endive lettuce were detected by almost all methods. Bacterial species belonging to the families Pseudomonadaceae, Enterobacteriaceae, Xanthomonadaceae, and Moraxellaceae were detected in most of the examined samples including some unexpected potentially human pathogenic bacteria, especially those with the potential to build resistance to antibiotics (e.g., Stenotrophomonas maltophilia (0.9 % in cut sample, 0.4 % in spin-dried sample), Acinetobacter sp. (0.6 % in raw material, 0.9 % in cut sample, 0.9 % in washed sample, 0.4 % in spin-dried sample), Morganella morganii (0.2 % in cut sample, 3 % in washed sample)) revealing the potential health risk for consumers. However, more seldom occurring bacterial species were detected in varying range by the different methods. In conclusion, the applied methods allow the determination of the microbiome's structure and its dynamic changes during postharvest processing in detail. Such a combined approach enables the implementation of tailored control strategies including hygienic design, innovative decontamination techniques, and appropriate storage conditions for improved product safety

    Scanning Electron Microscopy of 2,8-Dihydroxyadenine Crystals and Stones

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    The lack of purine salvage enzyme, adenine phosphoribosyltransferase (APRT), leads to 2,8-dihydroxyadenine stone formation and/or crystalluria because it is insoluble in urine. Urolithiasis composed of 2,8-dihydroxyadenine is not only formed in a complete defect of APRT, but also in a partial deficiency of this enzyme. The defect is inherited as an autosomal recessive trait, the homozygous state is associated with high urinary levels of 2,8-dihydroxyadenine and with crystalluria, calculus formation, and potential nephrotoxicity. Determination of the APRT activity will facilitate quantification of the enzyme deficiency and elucidation of the hereditary history. 2,8-dihydroxyadenine excretion in the 24-hour urine and its circadian rhythm were determined using a new method of high performance liquid chromatography determination. By means of a standard case presentation, we illustrate the analysis of urinary sediments and calculi as well as the scanning electron microscopic images of this kind of stone

    Gesteuerte Geweberegeneration bei intraossären Alveolarknochendefekten unter Verwendung einer doxycyclinhaltigen Barriere und autogenem Knochentransplantat

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    Das Ziel der Untersuchung war es, die klinische Wirksamkeit der doxycyclinhaltigen (4%) Poly(DL-Lactid)-Membran in Kombination mit einem autogenen Knochentransplantat (T) bei der Behandlung intraossärer, parodontaler Defekte gegenüber einer alleinigen Lappenoperation (K) zu bewerten. Es nahmen Patienten mit Parodontitis, die einen Knochendefekt mit einer radiologischen Tiefe von mind. 4 mm zeigten, an der Untersuchung teil. Bei jedem Patienten wurde nach Initialtherapie und nach Applikation eines lokalen Doxycyclinhyclatgels die Test- oder Kontrollbehandlung durchgeführt. Nach 12 Monaten zeigten sich klinisch relevante Alveolarknochengewinne und signifikante Veränderungen innerhalb der Gruppen. Die Unterschiede zwischen den Behandlungsgruppen waren jedoch nicht signifikant. Insbesondere die Raucher in der Testgruppe erzielten die gleichen Alveolarknochengewinne wie Nichtraucher und zeigten signifikant bessere Ergebnisse als Raucher, die nur die Lappenoperation bekommen hatten (p<0,05)

    Zwei Jahre pro-Q – Bilanz eines biokonformen Eutergesundheitsprogrammes

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    The pro-q-project is an udder health programme especially for organic farmers under Swiss conditions. The aim is to minimize the use of s antibiotics and to assure a good udder health state on the farms. At the end of the third project year of 100 project farms 16 participate for more than two years. The udder health situation of these 16 farms improved moderately in the second project year (37% of the cows with a so-matic cell count > 100’000/ml) compared to the year before project start (40% of the cows with a somatic cell count > 100’000/ml). Furthermore, a nearly linear increase of the arithmetic mean of herd lactation number (3.27 year before project start, 3.33 first project year, 3.44 second project year, resp.) could be found. The number of antibiotic treatments per cow and year decreased from 0.37 in the year before project start to 0.24 in the second project year
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