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Scheidler Stefan Anders Birte Regli Christian Bolay Stephan Huggenberger Peter 《Grundwasser》2019,24(4):277-286
Grundwasser - Topographically induced Alpine regional groundwater flow systems below the unconsolidated valley fillings constitute a substantial unused geothermal resource. Within the... 相似文献
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OBJECTIVE: Assessment of gall bladder cancer among cholecystectomy specimens. DESIGN: Retrospective study of all cholecystectomy specimens coupled with data from clinical oncology department. SETTING: Department of Pathology and Department of Clinical Oncology, Al Arab Medical University, Benghazi, Libya. SUBJECT: Gall bladder cancer among cholecystectomies and the pattern of survival of these patients. MATERIAL: Histopathology records available on all cholecystectomies performed between 1982 and 1997. Data available on staging and survival of cancer patients from clinical oncology upto 1996. RESULTS: Eighty nine cases of gall bladder cancer were found out of 7352 cholecystectomies performed over a period of 16 years. It was found more commonly in females with a mean age of 58.1 years. It was also observed that the incidence in males above 60 years was almost equal to that of females. Gall bladder cancer when primarily detected by the pathologist in cholecystectomy specimens removed for symptomatic cholelithiasis, was mostly in stage I. Most of the patients in stage III-IV cancer died within one year whereas most of the stage I cancer patients survived more than two years. CONCLUSION: Simple cholecystectomy is strongly advised in women above 50 years of age and in men above 60 years of age with symptomatic cholelithiasis. 相似文献
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The rheological behaviour of calcite suspensions made of particles with different size distributions, obtained by means of a wet comminution process, have been studied versus the operating conditions (volume concentration, use of dispersing agent). The suspension properties (size distribution, specific surface area [SSA]) were investigated in order to characterize the microstructure of the aggregated suspensions. The suspension acts as a thinning fluid with a yield value, and the viscosity increases when the particle size decreases (colloidal dispersions) due to attractive interparticle forces. The use of a polyelectrolyte (sodium polyacrylate [SPA]) during the size-reduction process allows strong reduction of the viscosity of the ground suspensions. The polymer is adsorbed onto the surface of the particles and, consequently, prevents aggregation and allows improvement of the process efficiency. 相似文献
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Doğan OM Bolayir G Keskin S Doğan A Bek B 《Journal of materials science. Materials in medicine》2008,19(6):2343-2349
This study was performed to determine whether some flexural properties of a denture base resin material could be improved
through reinforcement with five types of aesthetic fibers at 3% concentration by weight and in 2, 4, and 6 mm length. Five
specimens of similar dimensions were prepared for each of the test groups; base resin and the same resin with glass, rayon,
polyester, nylon 6 and nylon 6,6 fibers in three different lengths. Flexural properties were evaluated by using a 3-point
bending test. A visual examination was also made to determine mode of fracture of the specimens. The incorporation of different
fibers in varying lengths had no significant effect on flexural strength of the resin. The specimens reinforced with nylon
6,6 fibers of 6 mm length showed the highest flexural strength. Young’s modulus and maximum load suggests that such reinforcement
makes resin resistant to fracture. 相似文献
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O. Murat Dogan Giray Bolayõõir Ali Boztuğ Mehmet Turgut H. Bayram Zengin 《应用聚合物科学杂志》2007,104(2):1338-1341
The present study investigated the effects on the bonding between the denture base acrylic resin and the soft silicon based lining material of maleic anhydride‐styrene‐vinyl acetate (MA‐St‐VA) terpolymer and some of its ester derivatives. These ester derivatives were n‐propylmaleate‐styrene‐vinyl acetate (n‐PrMA‐St‐VA), n‐buthylmaleate‐styrene‐vinyl acetate (n‐BuMA‐St‐VA) and n‐benzylmaleate‐styrene‐vinyl acetate (n‐BzMA‐St‐VA). Fourier Transform infrared spectroscopy method was used to determine interactions between terpolymers with the acrylic resin and soft lining material. The tensile bond strength of all the groups was compared and the obtained differences were statistically significant (P < 0.05). The highest value was found for the samples lined with n‐BuMA‐St‐VA (2.11 ± 0.21 MPa) and the samples lined with n‐BzMA‐St‐VA had the lowest bond strength (0.3 ± 0.12 MPa). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1338–1341, 2007 相似文献
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Fatma Dilsad Oz Simge Canatan Sukran Bolay 《Journal of Adhesion Science and Technology》2019,33(9):986-1000
The aim of this study was to evaluate the repair bond strength of a dimethacrylate-based composite to two hybrid CAD/CAM blocks after different surface treatments. One hunded and twenty specimens were prepared from two different CAD/CAM blocks (Lava Ultimate (L), Cerasmart (C)). After thermal aging, specimens from each group (n?=?60) were divided into 6 treatment groups (n?=?10): (1) No treatment (2) Phophoric acid (37%) for 60?s, (3) Hydrofluoric acid (8%) for 60?s, (4) Sanblasting with 50-µm aluminium oxide (5) Er,Cr:YSGG laser treatment at 2?W and (6) Er,Cr:YSGG laser treatment at 3?W. Single Bond Universal was applied on all specimens and a dimethacrylate-based composite (Tetric N-Ceram) was bonded using Teflon tubes. After thermal cycling, shear bond strength (SBS) was tested, and failure modes were evaluated. Two-way ANOVA and independent t-test were used for statistical analysis (p?<?0.05). The highest SBS values were detected at Er,Cr:YSGG laser treatment groups (3W) (L:22.7?MPa, C:22.6?MPa). Lowest SBS values were obtained at no surface pretreatment groups followed by phophoric acid treatment groups which were significantly lower than sandblasting, hydrofluoric acid treatment and Er,Cr:YSGG laser treatment groups (p?=?0.001). The universal adhesive Single Bond Universal had no effect on promoting bond strength to hybrid ceramics alone or with phosphoric acid. Sandblasting, hydrofluoric acid and laser treatment were effective at increasing repair bond strength, for both Lava Ultimate and Cerasmart. 相似文献
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Dr. Christian Regli Dr. Peter Kleboth Dr. Urs Eichenberger Silvia Schmassmann† Peter Nyfeler Stephan Bolay MSc ETH 《Grundwasser》2014,19(1):29-38
In urban areas of the Swiss Alps the use of geothermal energy from several hundred meters depth becomes increasingly important. For this mainly open systems have priority. This work presents the first insights in the prospection and characterisation of the so far unexplored, utilizable, and abundant Aquifer of the Arosa Dolomites. Besides the use of established methods and techniques, such as seismic measurements, an exploration drilling, borehole geophysical measurements, and pumping tests, the application of the KARSYS-approach for geological and conceptual hydrogeological 3D-modelling of the aquifer is illustrated. In addition, the development of a viewer for 3D-visualization of drillings is documented. The hydrogeological and metrological approaches allow a lithological facies differentiation of the Arosa Dolomites, and a differentiation of the fractured and karstified areas within the aquifer. The results represent the basis for advanced findings optimizing and risks minimising exploration and drilling planning, and for sustainable utilization planning. 相似文献
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BACKGROUND AND PURPOSE: Failure of prompt motor recovery after spontaneous recirculation or thrombolytic therapy may be due to an unsatisfactory restoration of synaptic activity within cortex and/or blockade of electrical impulses at the severely ischemic subcortical region. METHODS: Afferent, efferent, and synaptic activities were focally examined within the rat sensorimotor cortex by recording the somatosensory-evoked potential (SEP) and motor area response evoked by stimulation of premotor afferents (PmEP) intracortically and the motor-evoked potential (MEP) generated by stimulation of the forelimb area from the brain stem. The effect of ischemia on electrical activity in the cortex and on axonal conduction in the subcortical region was studied differentially by proximal or distal occlusion of the MCA. RESULTS: MEP consisted of direct and indirect waves generated by direct activation of pyramidal axons and indirect excitation of pyramidal neurons via cortical synapses, respectively. MEP, PmEP, and SEP disappeared on proximal occlusion. Following reperfusion after 1 to 3 hours of ischemia, the direct wave of MEP readily recovered but the indirect wave showed no improvement, suggesting a restored axonal conduction but impaired cortical synaptic transmission. The synaptic defect, which also caused a poor recovery in PmEP and SEP and on electrocorticogram, was persistent and detected 24 hours after 1 hour of proximal occlusion. CONCLUSIONS: Our data suggest that motor dysfunction is caused by loss of cortical excitability and blockade of motor action potentials at the subcortical level during ischemia. After brief transient ischemia, axonal conduction readily recovers; however, a persistent transmission failure at cortical synapses leads to motor dysfunction. 相似文献
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Composites of poly(vinyl acetate) filled with calcium carbonate (CaCO3) have been synthesized in a ball mill. The different steps in fragmentation and agglomeration phenomena have been identified. The materials have first been ground separately to characterize their behaviour in the mill. Then, they were ground together. It has been shown that small CaCO3 fragments cover PVA particles, limiting for a first time the agglomeration of these and permitting their size reduction. Then, when PVA fragments are small enough, a competition between size reduction and agglomeration occurs, which favours the dispersion of CaCO3 in the matrix. It has also been observed that the presence of the filler does not modify significantly the molecular mobility of PVA. 相似文献
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Greenhouse gas emission savings of ground source heat pump systems in Europe: A review 总被引:2,自引:0,他引:2
Peter Bayer Dominik SanerStephan Bolay Ladislaus RybachPhilipp Blum 《Renewable & Sustainable Energy Reviews》2012,16(2):1256-1267
An overview is presented on the last decade of geothermal heating by ground source heat pumps (GSHPs) in Europe. Significant growth rates can be observed and today's total number of GSHP systems is above 1 million, with an estimate of about 1.25 million mainly used for residential space heating in 2011. These systems are counted among renewable energy technologies, though heat pump operation typically consumes electricity and thus only a fraction of the energy produced is actually greenhouse gas (GHG) emission free. Consequently, only in the most mature markets of the Scandinavian countries and in Switzerland, calculated emission savings reach more than 1% compared to standard heatings. However, Sweden shows that more than 35% is possible, with about one third of these systems in Europe concentrated in this country. Our calculations demonstrate the crucial role of country-specific heating practices, substituted heat mix and primary electricity mix for country-specific emission savings. For the nineteen European countries studied in 2008, 3.7 Mio t CO2 (eq.) are saved in comparison to conventional practice, which means about 0.74% on average. This reveals that many countries are at an early stage with great potential for the future, but even if the markets would be fully saturated, this average would barely climb to about 30%. These numbers, however, take the current conditions as reference, and when extrapolated to the future can be expected to improve by greener electricity production and increased heat pump performance. 相似文献
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