10,024 research outputs found
A Comparison of Adaptive Beamforming Implementations for Wideband Scenarios
No full textIn this paper, we compare low cost implementations of wideband adaptive beamformers utilising the generalised sidelobe canceller (GSC) in combination with the least-mean squares algorithms. DFT based techniques suffer from unjustified narrowband assumptions. We therefore derive and investigate an overlap-save implementation of the GSC, which offers a steady state suppression of jammers equivalent to a time domain GSC but may be prone to slow convergence. Finally, subband techniques offer a more robust convergence trade-off for a somewhat higher computational cost. Analysis and simulation results revealing some of the algorithms' properties are presented
„Melior est canis vivus leone mortuo”. Koh 9,4 w patrystyce greckiej i łacińskiej
No full textThe article discusses how Qo 9:4 was interpreted in the Christian tradition. Regarding the exegesis of Ecclesiastes, a different material is available. Various interpretations are derived not only from specifically exegetical literature but also from other kinds of works. On this basis, it is possible to observe the directions of the interpretation of this biblical book. To better understand the specific theme, it is necessary to analyze the history of the interpretation of this book in Christian antiquity when Qo 9:4 was interpreted in an allegorical manner or with the use of prosopopoeia. The attention is focused on the significant passages that report or evoke the verse in question. The Fathers treat Qo 9:4 only briefly, and in reality, Ecclesiastes was not greatly popular during the Patristic times. The passage was treated as an exegetical question to be resolved, an example of a proverb repeated in various environments, even the ecclesiastical one. The reflection on Qo 9:4 revealed numerous points of convergence as well as differences in the interpretation of this passage, thus establishing a platform for further interpretations of this text during the Middle Age.Artykuł stanowi analizę interpretacji Koh 9,4 w tradycji chrześcijańskiej. W odniesieniu do egzegezy tego wersetu ma się do dyspozycji materiał o różnym charakterze. Poszczególne interpretacje pochodzą nie tylko z pism specyficznie egzegetycznych, ale także z dzieł o innym charakterze. Na tej podstawie można dostrzec kierunki interpretacji całej biblijnej Księgi Eklezjastesa, a także pojedynczego wersetu. W celu lepszego zrozumienia specyficznej tematyki, najpierw zostaje przedstawiona historia interpretacji Księgi Eklezjastesa w starożytności chrześcijańskiej. Koh 9,4 był wyjaśniany w sposób alegoryczny lub z odwołaniem się do prozopopei. Następnie zostały przeanalizowane znaczące fragmenty dzieł odnoszących się do Koh 9,4. Ojcowie Kościoła zajmowali się Koh 9,4 tylko okazyjnie, bowiem cała księga nie była zbytnio popularna wśród kaznodziejów i egzegetów epoki patrystycznej. Koh 9,4 był traktowany jako problem egzegetyczny do rozwiązania, jako przykład porzekadła, które otrzymało różne wersje i było używane także w kręgach kościelnych. Refleksja nad Koh 9,4 w okresie patrystycznym znajduje wiele punktów stycznych, ale także istnieją różnice w poszczególnych wyjaśnieniach tego wersetu. W ten sposób stworzono płaszczyznę dla jego bogatszej interpretacji już w epoce średniowiecza
Project Koh Tao: Tackling water shortage
No full textAdditional Master Thesis - This report serves to inform the local government of Koh Tao on the status of their current water system and advises on an alternative in order to make sure that future tap water demand can be met in a sustainable and reliable manner.Civil Engineering and GeosciencesWater Managemen
A Comparison of Chitosan Adhesion to KOH and H2O2 Pre-Treated Electrospun Poly(3-Hydroxybutyrate) Nanofibers
No full textChitosan coatings could effectively increase the biostability and biocompatibility of biomaterials while maintaining their structural integrity. In this study, electrospun fibrous polyhydroxybutyrate (PHB) membranes were pre-treated with potassium hydroxide (KOH) or hydrogen peroxide (H2O2) and then modified with dopamine (DA) and glutaraldehyde (GA) to improve their adhesion with chitosan (CS). Scanning electron microscopy (SEM), water contact angles (WCA), and Fourier transform infrared spectroscopy (FTIR) were used to demonstrate the successful generation of DA and GA-modified PHB fibers. KOH pre-treated PHB membranes exhibited superior binding efficiency with CS at low concentrations compared to their H2O2 pre-treated counterparts. The thermal analysis demonstrated a considerable decrease in the degradation temperature and crystallinity of KOH pre-treated membranes, with temperatures dropping from 309 °C to 265.5 °C and crystallinity reducing from 100% to 25.59% as CS concentration increased from 0 to 2 w/v%. In comparison, H2O2 pre-treated membranes experienced a mild reduction in degradation temperature, from 309 °C to 284.4 °C, and a large decrease in crystallinity from 100% to 43%. UV-vis analysis using Cibacron Brilliant Red 3B-A dye (CBR) indicated similar binding efficiencies at low CS concentrations for both pre-treatments, but decreased stability at higher concentrations for KOH pre-treated membranes. Mechanical testing revealed a considerable increase in Young’s modulus (2 to 14%), toughness (31 to 60%), and ultimate tensile stress (UTS) (14 to 63%) for KOH-treated membranes compared with H2O2 pre-treated membranes as CS concentration increased from 0 to 2 w/v%
Użycie Księgi Koheleta w Ewangelii wg św. Łukasza
No full textThere are eight passages in the Gospel of Luke in which references to the Book of Qoheleth are visible (2:40.52; 8:5–8a; 8:25.35; 11:42; 12:2–3; 12:19; 12:20; 12:25). Most often, in the passages of the Third Gospel, one can see an echo of the words written by Ecclesiastes. However, this is not the only type of connection between these two texts. In Qoh 1:16, the hero depicted as Solomon may be the type of Jesus from Lk 2: 40,52. In Luke 12:19, however, a possible allusion to Qoh 8:15 can be observed, as well. The use of typology, allusions, and echoes in the aforementioned passages is part of the study of intertextual relationships between these texts. The author of the Third Gospel, using Qoheleth, reinterprets it.W Łk można wskazać osiem fragmentów, w których widoczne są odniesienia do Koh (2,40.52; 8,5–8a; 8,25.35; 11,42; 12,2–3; 12,19; 12,20; 12,25). Najczęściej w passusach trzeciej ewangelii można widzieć echo słów zapisanych przez Eklezjastesa. Nie jest to jednak jedyny rodzaj związku zachodzący pomiędzy tymi tekstami. W Koh 1,16 bohater przedstawiony jako Salomon może być typem Jezusa pokazanego w Łk 2,40.52. W Łk 12,19 można widzieć natomiast prawdopodobną aluzję do Koh 8,15. Użycie typologii, aluzji i ech w zaprezentowanych powyżej fragmentach wpisuje się w badanie zależności intertekstualnych pomiędzy tekstami. Autor trzeciej ewangelii poprzez użycie Koh dokonuje jego reinterpretacji
The contents of neutral sugar and others composition (relative %, w/w) of the alkali extraction obtained from sweet sorghum bagasse with treatment of NaOH and KOH.
No full textThe contents of neutral sugar and others composition (relative %, w/w) of the alkali extraction obtained from sweet sorghum bagasse with treatment of NaOH and KOH.</p
Removal of residual CO<sub>2 </sub>from feed water to increase the lifetime of KOH electrolyte
No full textZero Emission Fuels B.V. (ZEF) is a start-up who aims to design a sustainable methanol production micro-plant, using solely air and solar energy as an input. A subsystem that has yet to be designed just upstream of the alkaline (KOH) electrolyser, is the so-called degasser. The purpose of the degasser is to remove a residue of carbon dioxide (CO2) present in the feed water for the KOH electrolyser. The presence of this CO2 is caused by it being absorbed together with water, in the direct air capture (DAC) subsystem. It is important that the concentration of carbon dioxide in the feed water is minimized since it is known to react with KOH, decreasing the performance of the reactor. The aim of this thesis, is to develop a method to minimize the concentration of carbon dioxide in the feed water, which is feasible for the ZEF micro-plant. A literature study was performed based on which is concluded on the feasibility of three different degassing methods: membrane permeation, distillation and stripping. It was decided to further investigate the efficiency of a stripping device, by making a numerical model using Matlab and validating this model with experiments. For the base case model, a bubble column in the shape of a cylindrical pipe operating in the Taylor flow regime was used. The bubble column had an inner diameter of 6 mm. Operation at steady state, at a pressure of 50 bar and a temperature of 50 °C, resulted in a required length of 65 cm. It should be noted here, that the liquid flow rate was equal to that aimed by ZEF, but the gas flow rate was about three times as high. A sensitivity analysis was performed in which the temperature of the system was changed. As expected, the required length of the bubble column decreases with increasing temperature. A sensitivity analysis on the influence of recirculation of the gas phase, showed that the accumulation of carbon dioxide in the gas phase is of no limiting factor in the stripping process, so that with the gas flow rate of ZEF, recirculation can be an interesting option. Different setups were tested to validate the model with. However, since none of them showed a steady state behaviour, the model could not be validated with these experiments. The setup was changed slightly in order to perform batch experiments, so that the continuous system (based on theory) could be compared with the batch system (based on experiments). Results showed that both the batch and continuous mode are feasible for the ZEF micro-plant
Reakcja wymiany jonowej w podsieci a w strukturze krystalicznej pirochloru A2Ta2O6
No full textNa+ or K+ ion rechargeable battery is started to garner attention recently in Place of Li+ ion cell. It is important that A+ site ion can move in and out the positive-electrode materials. When K2Ta2O6 powder had a pyrochlore structure was only dipped into NaOH aqueous solution at room temperature, Na2Ta2O6 was obtained. K2Ta2O6 was fabricated from a tantalum sheet by a hydrothermal synthesize with KOH aqueous solution. When Na2Ta2O6 was dipped into KOH aqueous solution, K2Ta2O6 was obtained again. If KTaO3 had a perovskite structure was dipped, Ion-exchange was not observed by XRD. Because a lattice constant of pyrochlore structure of K-Ta-O system is bigger than perovskite, K+ or Na+ ion could shinny through and exchange between Ta5+ and O2− ion site in a pyrochlore structure. K+ or Na+ ion exchange of A2Ta2O6 pyrochlore had reversibility. Therefore, A2Ta2O6 had a pyrochlore structure can be expected such as Na+ ion rechargeable battery element.Akumulatory w którym jako nośniki ładunku wykorzystywane są jony Na+ lub K+ budzą coraz większe zainteresowanie jako alternatywa dla ogniw litowo-jonowych. Należy podkreślić, że kationy w podsieci A+ potrafią się przemieszczać z- i do dodatnio naładowanych materiałów elektrodowych. Gdy proszek K2Ta2O6 posiadający strukturę pirochloru zanurzono w roztworze wodnym NaOH w temperaturze pokojowej, otrzymano Na2Ta2O6. K2Ta2O6 otrzymano poprzez obróbkę arkuszu tantalu metodą hydrotermalną wykorzystując roztwór wodny KOH. Gdy zanurzono Na2Ta2O6 w wodnym roztworze KOH, otrzymano z powrotem K2Ta2O6. Natomiast, gdy zanurzono KTaO3 o strukturze perowskitu, nie obserwowano wymiany jonowej. Dlatego, że stała sieciowa w strukturze pirochloru układu K-Ta-O jest większa niż w przypadku perowskitu, jony K+ lub Na+ mogą się poruszać i wymieniać w podsieci Ta5+ i O2− w pirochlorze. Wymiana jonów K+ lub Na+ w pirochlorze A2Ta2O6 jest odwracalna. Z tego powodu można się spodziewać, że związek A2Ta2O6 o strukturze pirochloru może znaleźć potencjalne zastosowanie jako element akumulatora pracującego z jonami Na+
Land use changes imperil South-East Asian biodiversity
No full textNavjot S. Sodhi, Mary Rose C. Posa, Kelvin S.-H. Peh, Lian Pin Koh, Malcolm C.K. Soh, Tien Ming Lee, Janice S.H. Lee, Thomas C. Wanger and Barry W. Broo
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