Large-scale geo-energy development: sustainability impacts

Geothermal energy is a renewable and alternative energy with the potential to replace fossil fuels and help mitigate global warming. However, the development of geothermal energy has environmental, economic and social-cultural consequences, which needs to be predicted beforehand and then mitigated. To guarantee a sustainable development, it is, therefore, essential to consider the relative potential impacts. From a sustainability point of view, in the present study, a comprehensive analysis of consequences of geothermal energy development is conducted, including environmental, economic and societal & cultural dimensions. The geothermal energy industry will prosper only if sustainable aspects can be integrally considered.     

Biodegradation of Aqueous Organic Matter over Seasonal Changes: Bioreactor Experiments with Indigenous Lake Water Bacteria

Artificial groundwater recharge for drinking water production involves infiltration of surface water through sandy soil and its capture into a groundwater aquifer. The transformation of aqueous organic matter is one of the central issues in this process. The purpose of this work was to assess the potential of indigenous microorganisms in the source water to contribute in the aqueous organic matter biodegradation. For this purpose, microorganisms were enriched from the source water in a fluidized-bed reactor (FBR) and used for kinetic studies on biodegradation of organic matter at ambient temperature range. Lake water (total organic carbon 5.8?mg?L?1) was continuously fed to the FBR containing porous carrier material to support biomass retention. In the inlet and outlet water there were on average 21±6 and 13±5×105?cells?mL?1, respectively. Biofilm accumulation (as volatile solids) reached 13.1?mg?g?1 dw carrier. In the continuous-flow mode and the batch tests, the highest oxygen consumption rate appeared in the summer, followed by the fall, spring, and winter. At low temperatures, the biodegradation of aqueous organic matter was relatively rapid initially for labile fractions followed by a slower phase for refractory fractions. The average temperature coefficient (Q10) in the system was 2.3 illustrating a strong temperature dependency of oxygen consumption. The isotopic analysis of dissolved inorganic carbon δ13CDIC analysis revealed 27 and 69% mineralizations of dissolved organic carbon at 23 and 6°C over 65 and 630 min, respectively. These results can be used to construct additional input parameters in modeling applications of artificial groundwater recharge process. The biological component especially, i.e., the biodegradation, is difficult to predict for on-site applications without experimental proof and thus the interpretation in this study will help formulate design predictions for the process.     

Effect of 2-propanol and water contents on the crystallization and particle size of titanium dioxide synthesized at low-temperature

Two series of titanium dioxide, TiO₂, powder were prepared at a temperature of 50 °C without any catalyst. The effects of 2-propanol and water contents on the formation of crystalline powder mixture of anatase and brookite were systematically studied. The characteristics of produced powder were determined by employing X-ray diffraction, transmission electron microscopy, nitrogen adsorption test and Fourier transform infrared spectroscopy.     

The effects of laser patterning 10CeTZP-Al2O3 nanocomposite disc surfaces: Osseous differentiation and cellular arrangement in vitro

Customized square grid arrangements of different groove depths (1.0, 1.5 and 3.0?µm) and separations (10 and 30?µm) were successfully laser patterned, using a nanosecond pulsed fibre laser, on the surface of 10?mol% ceria-stabilized zirconia and alumina (10CeTZP-Al₂O₃) nanocomposite discs (diameter: 10?mm; thickness: 1.5?mm). The patterned surfaces and the in vitro biological response of osteoblasts (SAOS-2) towards them were thoroughly analysed. In terms of composition, the laser treatment was found to cause superficial monoclinic-tetragonal zirconia phase transformation and alumina evaporation. In vitro, the most effective grid configuration for osseous differentiation was found to be 1.5?µm groove depth and 10?µm groove separation, and confocal microscopy revealed that the cells show a tendency to be sorted as groove depth increases. It is thought that custom-made patterns could be produced to guide cell attachment in vivo, which could favour implant integration and reduce healing time.     

Ultrahigh Carrier Mobility Achieved in Photoresponsive Hybrid Perovskite Films via Coupling with Single‐Walled Carbon Nanotubes

Organolead trihalide perovskites have drawn substantial interest for photovoltaic and optoelectronic applications due to their remarkable physical properties and low processing cost. However, perovskite thin films suffer from low carrier mobility as a result of their structural imperfections such as grain boundaries and pinholes, limiting their device performance and application potential. Here we demonstrate a simple and straightforward synthetic strategy based on coupling perovskite films with embedded single‐walled carbon nanotubes. We are able to significantly enhance the hole and electron mobilities of the perovskite film to record‐high values of 595.3 and 108.7 cm² V^?1 s^?1, respectively. Such a synergistic effect can be harnessed to construct ambipolar phototransistors with an ultrahigh detectivity of 3.7 × 10¹⁴ Jones and a responsivity of 1 × 10⁴ A W^?1, on a par with the best devices available to date. The perovskite/carbon nanotube hybrids should provide a platform that is highly desirable for fields as diverse as optoelectronics, solar energy conversion, and molecular sensing.     

COMPLEX STABILITY OF SUGARS AND SUGAR ALCOHOLS WITH Na + , Ca 2+ , and La 3+ IN CHROMATOGRAPHIC SEPARATIONS USING POLY(STYRENE- CO -DIVINYLBENZENE) RESINS AND AQUEOUS ORGANIC ELUENTS

The complex formation between metal ions and carbohydrates in solvent mixtures has been studied by chromatographic measurements. The effect of noncomplexing partition was decreased by attaching the active groups only on the shell of the stationary phase particles. Poly(styrene- co -divinylbenzene) resin beads were surface-sulfonated for that purpose. Thus the inner part of the sulfonated bead remained inactive and nonswellable. The counter-ions examined were Na + , Ca 2+ , and La 3+ , and the organic cosolvents were ethanol and acetonitrile. The stability constants of the very weakly complexing D -glucose, D -xylose, and L -rhamnose, the weakly complexing D -fructose and L -arabinose, and the strongly complexing xylitol and D -sorbitol were determined. The increasing organic cosolvent content increased the retention times, which is explained by the increased complex stability between the complexing solute and the counter-ion. The effect was greatest for the complex-forming sugars in the Ca 2+ form and for the sugar alcohols in the La 3+ form. The organic cosolvent had only a minor effect on the weakly complexing components, whereas the complex stability of the strongly complexing xylitol and sorbitol in 50 wt% ethanol solution in the La 3+ resin was more than five times higher compared to the stability measured in pure water.     

Goniofluorometer for characterization of fluorescent materials

A goniofluorometer has been built that is capable of measuring in various viewing angles ranging from 10 degrees to 90 degrees . The incident angle can be varied from 0 degrees to 8 degrees . The goniofluorometer can measure bispectral luminescent radiance factors in the wavelength range of 250-800 nm. To our knowledge, there are no other reported results of similar devices capable of spectral measurements in various measurement geometries.