369 research outputs found
Institutions, Economic Development, and Deforestation
This paper offers a unified framework linking two important debates: First, the debate about the respective roles of geography and institutions on economic development; Second, the literature on the role of technological change and economic development on agricultural intensification and land use changes. We use this framework to study empirically deforestation patterns at the rainforest margin. To this end we specify an empirical model that can explore the causal chain ranging from geographic conditions via institutional change to economic development and deforestation. We estimate this model using a unique data set of villages at the rainforest margin in Indonesia. Our results show that geography-induced institutional change is the key driver of technological change in our villages. The bad news is that some of these processes along the causal chain seem to promote deforestation. The good news is that economic development, conditional on these effects, appears to reduce deforestation. --
Selective Catalytic Reduction of NOx by Propane in Oxidizing Atmosphere on Catalysts Based on Metals in Zeolite Matrices
8. Shrnutí Kombinace souboru spektroskopiclcých metod, Elektronové spinové rezonaDce. Infračervenéspektroskopie a Móssbauerovské spektroskopie, použitých za podmínek blízlcých in-situ experimentu, poskytla první ucelenou identifikaci jednotliých forem železa, přítomných v Fe-zeolitech (obsah Fe < 1%) několika strukturních typůa současně i popis jejich individuálních redoxních vlastností. Tyto výsledky umožnily komplexně diskutovat vztah mezi strukturou kata|yzátoru a jeho katalytickou aktivitou v selektiwí katalýické redukci No^ propanem v oxidačníatmosfeře. Závěrem |ze Ííci,ževšechny ři typy připravených a strukturně ana|yzovanýc|t kata|yzátori, tj. Fe-FER, Fe-BEA a Fe-MFI, představují vysoce efektivní systémy pro vedení procesu SCR oxidů dusftu propanem ve vysokém přebyku kyslíku. l55. CONCLUSIONS A set of spectroscopic techniques (electron spin resonance, infrared spectroscopy and Móssbauer spectroscopy) usď under conditions near to in-siÍu experiments provided for the frrst complex identification of individual řon species present in a group of pentasil zeolites, i.e. FER, BEA, and MFI' Identifiď structural parameters of individual iron sites and their redox properties in various types of zeolites provide9ttr::S1qilthe relationship between structure and catalyic performance of such materials for selective catalýic reduction of No* by propane in the presence ofoxygen. It has been shown that, while the individual types of Fe-zeolites differ in structural conditions for the individual processes controlling the final SCR perforrnance, in the temperature range 200 - 250.C these individual effects are effectively compensatď. on the other hand, Fe-BEA displays the best combination of structural features for supporting the reaction in the temperature range between 300 and 350.C. The catalýic activity above 350oC is then dominated by a catalyst ability to suppress the nonselective oxidation of propane, connectď to lower efficiency in targeting the řon cationic positions during catalyst preparation. Nevertheless, all three zeolites used provide structural conditions for preparation of highly...Katedra fyzikální a makromol. chemieDepartment of Physical and Macromolecular ChemistryPřírodovědecká fakultaFaculty of Scienc
Occupational medical prophylaxis for the musculoskeletal system: A function-oriented system for physical examination of the locomotor system in occupational medicine (fokus(C))
Occupational physicians are very often confronted with questions as to the fitness of the postural and locomotor systems, especially the spinal column. Occupational medical assessment and advice can be required by patients with acute symptoms, at routine check-ups, by persons who have problems doing certain jobs, and for expert medical reports as to the fitness of persons with chronic disorders or after operations. Therefore, for occupational medical purposes a physical examination must aim primarily to investigate functions and not structures or radiologic evidence. The physical examination should be structured systematically and according to regions of the body and, together with a specific (pain) anamnesis should provide a basis for the medical assessment
Visible light driven non-sacrificial water oxidation and dye degradation with silver phosphates: multi-faceted morphology matters
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The convenient synthesis of multi-faceted versusirregular shaped Ag3PO4microparticles for the visible light driven non-sacrificial water oxidation is reported. Strikingly, the multi-faceted particles are found to be more effective for oxygen evolution reaction (OER) by photocatalytic water oxidation in water and in phosphate buffer solutions as well as for dye degradation in comparison to the irregular shaped particles
Possible role of death receptor-mediated apoptosis by the E3 ubiquitin ligases Siah2 and POSH
<p>Abstract</p> <p>Background</p> <p>A functioning ubiquitin proteasome system (UPS) is essential for a number of diverse cellular processes and maintenance of overall cellular homeostasis. The ability of proteasome inhibitors, such as Velcade, to promote extrinsic apoptotic effects illustrates the importance of the ubiquitin proteasome system in the regulation of death receptor signaling. Here, we set out to define the UPS machinery, particularly the E3 ubiquitin ligases, that repress apoptosis through the extrinsic pathway. A cell-based genome-wide E3 ligase siRNA screen was established to monitor caspase-8 activity following the addition of TRAIL.</p> <p>Results</p> <p>Data from the high-throughput screen revealed that targeting the RING-finger containing E3 ligase Siah2 as well as the signaling platform molecule POSH (SH3RF1) conferred robust caspase-8 activation in response to TRAIL stimulus. Silencing Siah2 or POSH in prostate cancer cells led to increased caspase activity and apoptosis in response to both TRAIL and Fas ligand. The E3 activity of Siah2 was responsible for mediating apoptosis resistance; while POSH protein levels were critical for maintaining viability. Further characterization of Siah2 revealed it to function downstream of early death receptor events in the apoptotic pathway. The observed apoptosis resistance provides one biological explanation for the induction of Siah2 and POSH reported in lung and prostate cancer, respectively. Expanding on an initial yeast-two-hybrid screen we have confirmed a physical interaction between E3 ligases Siah2 and POSH. Utilizing a yeast-two-hybrid mapping approach we have defined the spacer region of POSH, more specifically the RPxAxVxP motif encompassing amino acids 601-607, to be the site of Siah2 binding.</p> <p>Conclusions</p> <p>The data presented here define POSH and Siah2 as important mediators of death receptor mediated apoptosis and suggest targeting the interaction of these two E3 ligases is a promising novel cancer therapeutic strategy.</p
Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: preparation of highly active and stable supported Pt catalysts in microemulsions
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We recently introduced a new method to synthesize an active and stable Pt catalyst, namely thermo-destabilization of microemulsions (see R. Y. Parapat, V. Parwoto, M. Schwarze, B. Zhang, D. S. Su and R. Schomäcker, J. Mater. Chem., 2012, 22 (23), 11605–11614). We are able to produce Pt nanocrystals with a small size (2.5 nm) of an isotropic structure i.e. truncated octahedral and deposit them well on support materials. Although we have obtained good results, the performance of the catalyst still needed to be improved and optimized. We followed the strategy to retain the small size but change the shape to an anisotropic structure of Pt nanocrystals which produces more active sites by means of a weaker reducing agent. We found that our catalysts are more active than those we reported before and even show the potential to be applied in a challenging reaction such as hydrogenation of levulinic acid.DFG, EXC 314, Unifying Concepts in Catalysi
Quantification of photocatalytic hydrogen evolution
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A new photoreactor with defined irradiation geometry was developed and tested for the water reduction reaction using carbon nitride (“C3N4”) as a photocatalyst. The hydrogen evolution rate was investigated with a sun simulator (I = 1000 W m−2) in two different operation modes: circulation and stirring of the catalyst dispersion. Only in the stirred mode, where shear stress is lower, a stable hydrogen evolution rate of about 0.41 L m−2 h−1 is obtained. It is confirmed by experiments with D2O that hydrogen is obtained from the water splitting process and not by dehydrogenation of the sacrificial agent. The obtained rate results in an efficiency of <0.1% based on a reference experiment with a photovoltaic-powered electrolysis setup. The change from distilled water to tap or simulated sea water results in a lower hydrogen evolution rate of about 50%.BMBF, 03IS2071D, Light2Hydroge
Der Karlsruher Physikkurs für die Sekundarstufe II : Mechanik
Der Karlsruher Physikkurs ist ein Lehrbuch für die Sekundarstufe des Gymnasiums: 3 Bände für die Sek I und 5 Bände für die Sek II. Ihm liegt eine einheitliche Sachstruktur zu Grunde. Er ist dadurch leicht verständlich und gleichzeitig kompakt. Außerdem werden Barrieren zu Nachbardisziplinen abgebaut. Veraltete Konzepte wurden eliminiert, die Zahl der Fachausdrücke stark reduziert. Er wird gern gelesen von Jungen und Mädchen
XPS studies on dispersed and immobilised carbon nitrides used for dye degradation
Liquid phase adsorption is a common technique in waste water purification. However, this process has some downsides. The removal of environmentally harmful contaminants from organic liquids by adsorption produces secondary waste which has to be treated afterwards. The treatment can be e.g. high temperatures or a landfill. Photocatalysts such as CN6 can remove the dye under light irradiation but most times they have to be separated afterwards. Immobilisation of these photocatalysts can be one way to address this problem. The resulting photocatalyst layers were analysed in operando by near-ambient pressure XPS. This enabled us to detect the active species, i.e. oxygen radicals, at the surface, responsible for the dye degradation.TU Berlin, Open-Access-Mittel - 201
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