Geothermal assessment of the deep aquifers of the northwestern part of the Bohemian Cretaceous basin, Czech Republic

Groundwater in the Benešov-Ústí aquifer system in the northwestern Bohemian Cretaceous basin has been intensely exploited since the twentieth century. Apart from providing drinking water, it contains the most extensive accumulation of thermal water in the country. However, excessive exploitation can result in temperature declines and changes in the quality of the groundwater in the future. More than a hundred in situ temperature measurements were used to assess the geothermal gradient and heat flux. However, intense groundwater vertical flow across the well significantly controls the heat flux distribution, resulting in a huge range of values—from less than 50 mW/m² within infiltration areas to more than 125 mW/m² in drainage areas. Certain simplifications and corrections considering the vertical flow between different permeable zones were developed, and the correction for topography as well as lithological variability have been applied to improve accuracy of the geothermal gradient assessment. Despite the fact that the Bohemian Cretaceous basin is tectonically very complex, it is concluded that tectonics [with the exception of the Eger (Oh?e) rift] has only a secondary effect on the thermal field. Two longitudinal W-E areas in the Benešov-Ústí aquifer system have elevated heat flux values. The calculated heat flux values are useful for heat transfer modelling and the assessment of the sustainable limits of thermal water exploitation.     

Spectroscopic and Antimicrobial Activity of Hybrid Chitosan/Silica Membranes doped with Al2O3 Nanoparticles

Silicon - Chitosan/silica nanocomposite membrane doped with Al2O3 nanoparticles is prepared via sol–gel route by mixing the inorganic silica-based in the chitosan matrix. Understanding the...     

Harnessing technology in collaborative renewable energy education

ABSTRACT

A state-of-the-art eLearning renewable energy course, which consists of a number of topics and a practical component with several experiments, has been designed to showcase the paradigm for reform and modernisation of engineering curriculum in Jordan. The online experiments were physically distributed in four universities that cover most of the geography of the country. The experiments can be conducted by students over the internet at any time from anywhere by any student in the country. The eLearning course was piloted and delivered to students jointly in four universities over a period of two years. The experiments encompassed topics on wind and solar photovoltaics power generation, solar tracking control, hybrid energy and fuel cells. The teaching effectiveness from the perspective of the students was investigated and feedback from faculty members, technicians and students supporting the delivery of the courses was explored. The results actually show a promising endorsement by students of this innovative approach and demonstrate clearly their passion for reform, renovation and novelty. The new model for the online course may be integrated into the corresponding curriculum and engineering study plans as its evaluations by both professors and students were found significantly favourable.     

Poisson’s ratio of the MDF in respect to vertical density profile

The work deals with Poisson’s ratios (PR’s) of medium density fiberboard (MDF) measured using digital image correlation and correlated to vertical density profiles (VDP). MDFs of four different thicknesses were first scanned by X-ray to obtain VDPs and then subjected to compression while measuring by DIC. PR’s of MDF reveal low correlations with VDP (<0.08), but strong local behavior ranging from 0.025 to 0.06 for 12 mm thickness, from 0.018 to 0.105 for 18 mm, from 0.03 to 0.175 for 25 mm, and from 0 to 0.43 for 38 mm.     

Datenschutz im Web 2.0 am Beispiel des sozialen Tagging-Systems BibSonomy

Soziale Tagging-Systeme geh?ren zu den in den vergangenen Jahren entstandenen Web2.0-Systemen. Sie erm?glichen es Anwendern, beliebige Informationen in das Internet einzustellen und untereinander auszutauschen. Je nach Anbieter verlinken Nutzer Videos, Fotos oder Webseiten und beschreiben die eingestellten Medien mit entsprechenden Schlagw?rtern (Tags). Die damit einhergehende freiwillige Preisgabe oftmals pers?nlicher Informationen wirft Fragen im Bereich der informationellen Selbstbestimmung auf. Dieses Grundrecht gew?hrleistet dem Einzelnen, grunds?tzlich selbst über die Preisgabe und Verwendung seiner pers?nlichen Daten zu bestimmen. Für viele Funktionalit?ten, wie beispielsweise Empfehlungsdienste oder die Bereitstellung einer API, ist eine solche Kontrolle allerdings schwierig zu gestalten. Oftmals existieren keine Richtlinien, inwieweit Dienstanbieter und weitere Dritte diese ?ffentlichen Daten (und weitere Daten, die bei der Nutzung des Systems anfallen) nutzen dürfen. Dieser Artikel diskutiert anhand eines konkreten Systems typische, für den Datenschutz relevante Funktionalit?ten und gibt Handlungsanweisungen für eine datenschutzkonforme technische Gestaltung.     

The effect of calcium zirconate modifications on the microstructure and functional properties of sodium niobate thin films prepared by chemical solution deposition

Sodium niobate thin films doped with manganese (NN), and NN films modified with 5 or 10 mol % calcium zirconate (CZ) on platinized silicon substrates were prepared by chemical solution deposition. The 250-nm-thick films crystallize in a perovskite phase with fine, equiaxed grains. The NN films exhibit well-shaped ferroelectric loops with a remanent polarization and coercive field of ～10 μC/cm² and ～100 kV/cm, respectively. The modification with CZ strongly influences the ferroelectric response of the films: the remanent polarization progressively decreases to around 2.5 μC/cm². The absence of an anti-ferroelectric response, which has previously been confirmed in bulk NN-CZ ceramics, is attributed to the nanoscale microstructure and residual thermal stresses. All the studied films exhibit a piezoelectric response with the highest piezoelectric d₃₃ coefficient of 35 pm/V at 300 kV/cm bias field for the NN modified films with 5 mol % CZ, making them candidates for lead-free piezoelectric thin-film applications.     

Black Raspberry Seed Oil Improves Lipid Metabolism by Inhibiting Lipogenesis and Promoting Fatty‐Acid Oxidation in High‐Fat Diet‐Induced Obese Mice and db/db Mice

The objective of this study was to evaluate the beneficial effect of α‐linolenic acid‐rich black raspberry seed (BRS) oil on lipid metabolism in high‐fat diet (HFD)‐induced obese and db/db mice. Five‐week‐old C57BL/6 mice were fed diets consisting of 50% calories from lard, 5% from soybean, and 5% from corn oil (HFD), or 50% calories from lard and 10% from BRS oil (HFD + BRS oil diet) for 12 weeks. Six‐week‐old C57BL/KsJ‐db/db mice were fed diets consisting of 16% calories from soybean oil (standard diet), 8% from soybean, and 8% from BRS oil, or 16% from BRS oil for 10 weeks. The BRS oil diets lowered the levels of triacylglycerol, nonesterified fatty acids, and total cholesterol in serum and liver of both of the obese and db/db mice as compared with the HFD and standard diet, respectively. mRNA levels of lipogenesis markers including cluster of differentiation 36, fatty‐acid‐binding protein 1, sterol regulatory element binding protein 1c, fatty‐acid synthase, and solute carrier family 25 member 1 in the liver of the BRS oil groups were lower than those in the liver of the HFD and standard groups in the obese and db/db mice, respectively. On the other hand, fatty‐acid oxidation markers including carnitine palmitoyltransferase 1A, acyl‐CoA dehydrogenase, hydroxylacyl‐CoA dehydrogenase α, and acyl‐CoA oxidase in the liver of the BRS oil groups were higher than those in the liver of the HFD and standard groups in the obese and db/db mice, respectively. Peroxisome proliferator‐activated receptor α mRNA and protein levels increased in the liver and epididymal adipose tissue of the obese and db/db mice fed BRS oil compared with HFD and standard diet, respectively. BRS oil might improve lipid metabolism by inhibiting lipogenesis and promoting fatty‐acid oxidation in HFD‐induced obese and db/db mice.     

Dilution Processes of Rainfall-Enhanced Acid Mine Drainage Discharges from Historic Underground Coal Mines,New Zealand

Mine Water and the Environment - In much of the world, seasonal weather patterns cause a flush of dissolved contaminants from mined areas at the beginning of wet seasons. However, on parts of New...     

The role of V<Subscript>2</Subscript>O<Subscript>5</Subscript> on the Structural and Optical Properties of MgO-ZnO-CdO-P<Subscript>2</Subscript>O<Subscript>5</Subscript> Glasses and the Impact of Gamma Irradiation

The quaternary glasses of mixed divalent oxides including ZnO, MgO, CdO within a phosphate network former were prepared. Vanadium pentoxide was introduced as a dopant in the range from 0.5 to 3%. Optical and infrared absorption studies for all glass samples were carried out. The optical spectra reveal the presence of both V³⁺ and V⁴⁺ ions in the studied host mixed divalent oxides phosphate glass. Fourier transform infrared absorption spectral analysis indicates the appearance of distinct vibrational bands due to the presence of characteristic phosphate groups depending on the glass composition and the ratio of V₂O₅ content. The optical band gap and Urbach energy were calculated and discussed in relation to the effect of V₂O₅ content. Finally, the glasses were optically and structurally examined affter gamma irradiation with a dose of 80 KGy.     

Forensic investigation to detect forgeries in ASF files of contemporary IP cameras

Recent years have seen tremendous increase in crime and terrorism all over the world which has necessitated continuous surveillance of public spaces, commercial entities and residential areas. CCTV cameras are an integral part of any modern surveillance system and have evolved significantly. They are a vital part of any investigation that follows a criminal or terrorism incident by providing invaluable evidence. In this paper, we show that the Advance Systems Format (ASF) file used in most IP cameras, which is also the main file containing metadata about the streaming packets, is vulnerable to forgery. This file is stored in plain text and any technically savvy person can forge it; therefore, a mechanism is needed to prevent it. To that end, we have gathered critical artifacts from an ASF file of IP cameras and carried out their forensic analysis. The analysis performed during this study demonstrates successful detection of forgery/tampering of evidence in IP cameras.