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Mixed economy with Chinese Characteristics : Embedding Market Mechanism in a Relational System
Get PDFOver last three decades, Chinaa s economic success amazed the world. It can be traced back to the year 1978 when the Communist Party of China decided to pursue a a reform and opening upa policy. There are a lot of literature on the subject. However, the cultural aspect of China's economic transformation lacks in the existing literature. As this dissertation suggests, the Chinese economy is embedded in a relational system, which is helpful to the essential institutional transition from central planning to market. This dissertation studies how a relational system affects the market structure from a dynamic perspective and investigates the agricultural, industrial and financial sector respectively. The Household responsibility system, the township and village enterprises and private lending system are several key institutional innovations based on the cultural embedding of market mechanism. Chinese economy is indeed a mixed economy in the sense of mixing the relational and market system
Decadal to centennial variability of (sub-) Arctic sea ice distribution and its paleoenvironmental significance
Get PDFThe modern sea ice loss has raised the concern about the natural variability of Arctic sea ice and its relation to short term climate changes. The reconstruction of past sea ice changes based on sediment cores and analyses of specific proxies provides vital knowledge about the natural variability of sea ice in pre-industrial times. Particular important areas for sea ice reconstructions are the shelves around Greenland. They underlie the major outflow of freshwater and sea ice from the Arctic to the North Atlantic. In this context, the late Holocene is of major interest, as it encompasses several well-known short-term climate events. For past sea ice conditions and open-water phytoplankton production, the application of specific biomarkers (IP25, HBI III, brassicasterol and dinosterol) have proven as useful and reliable proxies. In this study, biomarker concentrations in surface sediments are compared to modern sea ice concentrations to confirm the applicability of the IP25/PIP25 approach. Following this, late Holocene sea ice conditions are reconstructed on two sediment cores from the East (PS2641-4/PS2641-5) and West Greenland Shelf (MSM05/3-343310)
Towards comprehensive policy-evaluation : reassessing the effects of labour market and social policies from an interdisciplinary perspective
Get PDFLabour market and social policies have far-reaching consequences for the lives of citizens and the society as a whole. Up to now, the evaluation of these policies has focussed on its economic effects. This dissertation aims at bringing a broader perspective to scientific policy-evaluation that considers economic as well as social, political or psychological consequences of public policies. The relevance of this argument is confirmed by the finding that labour market policies appear to have non-negligible effects along several different dimensions, which highlights that policy-goals often stand in a trade-off to each other. The main methodological innovation of this dissertation lies in the development of new research designs for the anaylsis of causal relations in social sciences
Drogenbezogene Gesundheitsfürsorge in Haft : Bedarf und Angebot - Stärken und Schwächen
Get PDFBackground: The two main obstacles of the German penal system are reintegration of the prisoner and protection of the general population. Prevention and treatment of drug-related disorders are less important. In addition, there is a lack of financial resources for health-related services in prison and specialized prison staff in addiction medicine. The execution of criminal justice in Germany falls within the domain of the German Laender. Since 2006, the Laender have also been responsible for legislation in this area. There is no established national data collection procedure on the health of prison inmates in Germany. However, regional data surveys and individual studies focusing on sub-populations of individual facilities do exist. In order to create standardized treatment guidelines for drug users in prison, a comprehensive overview and a nationwide regulation are needed. Therefore, national data are being collected to assess quality and quantity of drug-related health care services in German prisons. The aim of this dissertation is to demonstrate structural strengths and weaknesses of drug-related health care in German prisons. Methods: A mixed-methods approach was chosen. Quantitative data was collected using a comprehensive questionnaire, which was sent to the Ministries of justice of all 16 Laender. The questionnaire collected data about the percentage of drug use, intravenous drug use and infectious diseases on reception into prison and during imprisonment, as well as type and extent of drug-related health care services in German prisons. Reference date was 31st March 2010. Qualitative data was collected via 15 qualitative semi-structured interviews, of which 11 were conducted in Bavaria and 4 in Berlin. Data was collected and compared in 2 Laender, which have two very different approaches concerning the drug problem: Bavaria, a territorial state, restrictive and emphasising sanctions and Berlin, a city state, with a focus on harm reduction. Interviewees were prison health care staff and consultants, prison guards, a former prisoner, prison nurses, and probation officers. In the interviews, respondents were asked to describe their everyday work, its challenges and how those challenges could be addressed. The interviews were analysed using GABEK WinRelanA and results were presented in network graphs. Results and Discussion: 14 out of 16 Laender answered the questionnaire. There was an average of 50 % missing items. Another half of the missing items was commented with a data is not recordeda . Concerning drug use the results show that around 30 % of the prisoners were tested upon admission. Upon admission the percentage of positive results was higher than during imprisonment (45 % vs. 16 %). Results show that during imprisonment, there is especially a decrease in the use of opioids (17 % vs. 10 %) and cocaine (10 % vs. 1 %). In contrast, the percentage of positive drug tests increased for some substances, especially for Cannabis (57 % vs. 75 %) and a othera substances (1 % vs. 15 %). Concerning intravenous drug use, results indicate a percentage of 47 % intravenous drug users among all drug users, which equates to 11 % of all prisoners. Concerning infectious diseases, around 50 % of the prisoners were tested upon admission, with 0,8 % tests positive for HIV, 1,8 % positive for Hepatitis B and 15 % positive for Hepatitis C. The results of the questionnaire in combination with the interviews, several topics turned out to be of relevance: the role of the justice system in strengthening the motivation to abstinence, therapy instead of punishment, working in a prison and (not) being part of the justice system, educating prisoners and prison guards, vaccinating, testing and treating of infectious diseases, harm reduction services, opioid substitution therapy and preparations for release. Taking together the results of this study, it can be summarized that at the time of the data collection there was no equivalent health care in German prisons compared to the general population. There is still a huge potential for improvement of the criminal justice system and especially of the prison health care system concerning drug use inmates. Change processes take a while and usually start on an individual level
High-speed Direct Laser Interference Patterning of sheet metals for friction reduction in deep drawing processes
Get PDFFriction has a dominant influence on manufacturing processes. In deep drawing of sheet metals, lubricants are regularly used to reduce friction forces. Significant production costs originating from supply, application, removal and disposal as well as the negative environmental consequences of using lubricants promote extended research on lubricant free deep drawing processes and tools. A combination of macro-structuring in the flange area and micro-structuring of ta-C layers at the pulling edge radius of deep drawing tools is identified to compensate the loss of tribological functions. Surface texturing of semi-finished sheet metals supports the friction reduction by minimizing the contact area to the deep drawing tool. In this study, a new concept for sheet metal texturing is presented. Using Direct Laser Interference Patterning, periodic surface patterns are fabricated at high fabrication speeds and their influence on the friction behaviour is tested by means of draw bend test. The results show minimal friction for ta-C covered draw bend tools and sheet metal structuring in bending direction
The variability of sea ice in the Fram Strait throughout glacial-interglacial transitions of the Late Quaternary (MIS 11 to MIS 1)
Get PDFThe objective of this thesis was the reconstruction of sea ice variability in the Fram Strait throughout glacial-interglacial transitions of the Late Quaternary. For this purpose, analyses of molecular biomarkers were carried out on eight sediment cores along the western and northern Svalbard Shelf (PS93/006-1, PS92/039-2), the East Greenland Shelf (PS93/016-6, PS93/031-4) as well as the central Arctic Ocean (PS87/023-1, PS87/030-1, PS87/070-1, PS87/079-1). These records provided valid insights into the Arctic paleoenvironment since Marine Isotope Stage 11. In order to reconstruct past sea ice cover, the sea ice proxy IP25 was applied in combination with the related phytoplankton-IP25 sea ice index PIP25. Further specific biomarkers were used to reflect the sea surface temperatures (glycerol dialkyl glycerol tetraethers), the marine production (brassicasterol, dinosterol, tri-unsaturated highly-branched isoprenoids) and the input of terrigenous material (campesterol, I -sitosterol)
Understanding geodynamic processes from sediments : detrital thermochronology and Cosmogenic Nuclide analyses from the Himalayas
Get PDFDetrital thermochronology is commonly utilized in geological research to quantify the thermotectonic history of orogens by looking at their erosional products. As such, understanding how the erosional processes infl uence the age distribution is necessary. For instance, the calculation of apatite (U-Th-Sm)/He (AHe) ages requires a correction for He loss by alpha-ejection at grain margins. However, in detrital minerals, the He-depleted outer part of the grain may be mechanically and chemically abraded during sediment transport, leading to over-correction of AHe ages. Consequently, in the fi rst part of the thesis, the focus is directed on developing an appropriate sampling strategy to measure the effect of the abrasion on the apatite crystals. We took sand samples from the upper drainage of the Kali Gandaki River in central Nepal in order to find continuously abraded apatites. Samples of the igneous source rock (the Mustang granite) were also dated by AHe and apatite fission track (AFT), to pinpoint the age signal of the source rock. The resulting distribution of detrital AHe ages of sand samples is in good agreement with published geologic constraints and provide the first evidence on the long-term erosion and exhumation history of the Mustang-Thakkhola graben, where virtually no thermochronological constraint yet exists. Furthermore, we demonstrate that abrasion of the detrital apatite grains is a major consequence of river transport within the first kilometres of river transport. We find evidence that the best approach in detrital settings is to analyse a homogeneous grain population but, in this case, the degree of alpha-correction application has to be considered carefully to achieve the distribution of the AHe ages that best represent the underlying cooling patterns. Furthermore, detrital thermochronology is enhanced by applying multiple techniques: to better resolve the cooling history of the Mustang graben, the AHe dataset is integrated with detrital AFT ages. To robustly interpret the combined age distribution, these AHe and AFT ages are compared to synthetic age predicted by a numerical model. The model finds the best agreement between synthetic and real data, by varying a set of parameters that relate to tectonic events and comparing,. The main outcome of the study is the clear constrain of the onset of extension between 13 and 11 Ma. When this result is interpreted in the frame of other neighbouring extensional structures, the Thakkhola graben appears as part of a larger system that accommodates arc-parallel extension and thus share a common timing of onset. In a third and final step, detrital AHe ages are is related to erosion rates obtained with cosmogenic nuclide 10Be. We collected 14 detrital river sand and 3 bedrock samples fromthe southern margin of the Shillong Plateau to measure erosion rates using the terrestrial cosmogenic nuclide 10Be. Erosion rates derived from cosmogenic 10Be from the deeply incised southern valleys of the Shillong Plateau are surprisingly low (50 to 80 m M y-1 ) in a region that is steep, tectonically active, and receives 7 m of annual rainfall. From our measured catchment-averaged erosion rates and estimates of the incised sediment volumes, we quantify the temporal duration of incision in the incised portion of the landscape, which we in turn relate to the onset of surface uplift. The resulting estimates, ranging from 4.4 A /- 0.6 to 4.6 A /- 0.7 Ma, match well with a set of external constraints and available low-temperature thermochronology data, and thus appear to provide a robust estimate for the initiation of surface uplift. In summary, the findings of this thesis highlight that detrital apatite (U-Th-Sm)/He thermochronology, especially in combination with other methods, such Apatite Fission Tracks or Cosmogenic Nuclide dating, is an effective method to address specific problems in the field of geodynamics and tectonic geomorphology
Biocatalytic quantification of laminarin : a major carbohydrate polymer in the ocean
Get PDFIn this work, I provide evidence that laminarin, the energy storage glucan of marine diatoms and many other algae, is a central bioenergy molecule of the ocean. This conclusion stems from the quantification of this molecule with new technology that I developed during my thesis. This biocatalytic assay is based on specific enzymes from marine microbes. This first quantification yielded an average contribution of laminarin to the carbon in algae derived organic matter of 37- 19% in the environment. The work contributes to our general understanding of the marine carbon cycle in the surface water of the ocean. In this environment, microalgae sustain approximately half of the global primary production and yield significant amounts of organic carbon in the form of polysaccharides, e.g. laminarin. So far, the role of this class of biological macromolecules in the carbon cycle is poorly understood due to the technological challenges in their analysis. The quantification of a single marine polysaccharide on a broad scale has therefore never been done. Our new approach starts to close this gap of knowledge and technology. It makes use of the enzymatic toolkit from marine microbes, that evolved specific enzymes in order to gain energy and carbon from the abundant carbohydrates. I demonstrate the advantages and the further potential of these enzymes for a faster, stereo- and sequence-specific analysis of selected polysaccharides in marine organic matter. In order to promote its further application, the method is now accessible for researchers in all fields of environmental science and can be easily applied to quantify laminarin in particulate organic matter from the marine environment. The characterization of the microbial machinery for the degradation of laminarin was required for the method development. However, it also contributed to the in-depth investigations that were made on two strains of specialized laminarin degrading bacteria. Environmental proteomics and metagenomics in combination with cultivation experiments, uptake visualization and our biochemical and crystallographic characterizations revealed streamlined bacteria that reach high abundances during repeating algal bloom events but also dominate the laminarin turnover in a highly competitive manner. Finally, I applied our new laminarin quantification method to environmental samples. I used particulate organic matter from two environmental time series, in different size fractions, vertical profiles, marine snow particles and a meridional transect in oceanic regions ranging from the Arctic, the North-, Central- and South-Atlantic, the coastal Pacific and the North Sea. Our measurements allow a more accurate estimation of the global annual laminarin production of 18- 9 gigatons. The varying levels of laminarin indicated different bioenergetic states of the oceanic regions and the ecological relevance of this molecule was highlighted by its sheer abundance of more than one third of the particulate organic carbon in surface waters
Melderegister, Mixed-Mode und Teilnahmeanreize : ein Modell zur Rekrutierung von Teilnehmern für sozialwissenschaftliche Panelbefragungen
Get PDFSurveys, or survey designs still represent the silver bullet in quantitative-oriented social sciences. However, surveys often suffer from two major problems: first, the systematic under-representation of individual population groups (Coverage Error) and second low response rates (Nonresponse Error). Since these two phenomena are usually not coincidental but systematic, data quality often suffers from their occurrence. Research on overcoming these problems, which often cause systematic biasing of surveys, is still lacking. Hence, the overall research goal of this doctoral thesis is to address these gaps by investigating the possibilities of decreasing the coverage error as well as measuring the nonresponse error. Based on data collected from the PPSM Access Panel in the years 2012 and 2014, I developed a heuristic model, which consists of four parts: (A) Register based sampling and paradata, (B) mixed-mode design, (C) postal advance notification of survey request and (D) incentives. Applying the propensity score method and the random response model, findings show several insights to the measuring of the effect of nonresponse on the given answers in the survey. Regarding the use of various incentives, this study demonstrates that the education bias can be reduced by the use of monetary incentives, which are assigned independently of participation. Surveys carried out via the internet are more likely to be affected by distortions caused by non-coverage, since there is no framework for interviewing the general population over the internet. As a result, the recruitment of respondents often takes place offline by telephone or by postal mail. The findings of this dissertation show that pre notification letters have a positive effect on the response rate. The additional information of the address based sampling frame could be used to examine the differences between respondents and nonrespondents via the random response model and possible effects of these differences on the given answers. All members of the sample received a pre notification letter, regardless of having access to the internet or a landline telephone. In connection with a mixed mode design (CAWI, CATI) the negative effect of the coverage error on data quality could be minimized. The best method for the recruitment of members for an access panel, this study concludes, is a pre notification letter in connection with a telephone call and monetary incentives of five euros, which are assigned independently of participation. Finally, besides discussing the resulting empirical implications for research, the findings also provide actionable recommendations for research practice
Numerical investigation of MPD thrusters using a density-based method with semi-discrete central-upwind schemes for MHD equations
Get PDFThe magnetohydrodynamic (MHD) equations which combines the Navier-Stokes equations with the Maxwell equations are essential for the investigations of many research areas as earth's core modelling, metal casting, fusion devices and electrical and aerospace devices. In the present work, the central-upwind schemes proposed by Kurganov, Noelle and Petrova for hydrodynamics are extended and combined with the divergence cleaning method of Dedner in order to investigate the performance of the self-field and applied magneto-plasma dynamic thrusters which still involving some outstanding problems. This new algorithm is developed for the single temperature, ideal and resistive MHD equations in a finite volume discretization framework with Gaussian integration. The electrical conductivity is predicted according to the Spitzer-Härm formulation and the real gas ratio of specific heats proposed by Sankaran is implemented for higher discharge current. To improve the quality of the solution, the limiter function of first and second order interpolation scheme is used. The accuracy and the robustness of the obtained solver are demonstrated through numerical simulations of ideal MHD benchmark problems. first, the ability of the developed code to handle shocks, rarefactions and contact discontinuities is tested with the Brio-Wu shock-tube problem. The Minmod and the Van Albada limiter functions has been found to perform better than the other limiter used and the obtained results agree well with both the analytic and the simulations results of previous work. Secondly, the complex and multiple shock interactions and the transition from smooth to turbulent flow involved in the Orszag-Tang vortex problem is well described by the present code and the comparison with the WENO-5 scheme of Shen shows good agreement. Lastly, The ability to described the interaction of an denser cloud with a MHD shock is tested by simulating the 2D cloud-shock interaction problem. The main phases of the interaction are well captured by the solver and the temporal progression of the density contour is in accordance with those obtained by Xisto. The ability of the developed resistive solver to deal with plasma flow acceleration is tested by simulating the well experimental investigated thrusters: The full scale benchmark thruster and the extended anode thruster of Princeton. The results show good agreement with the experimental and simulations results of previous work for discharge current less than the critical current just before the beginning of the onset phenomenon. Simulations are also conducted on the Villani-H thruster to determine the effect of geometric changes over the thruster performance and a first designing attempts is proposed according to the stability analysis. Confident with the results obtained with ideal and resistive MHD problems, the present code is extended to applied-field MPD thrusters. The purpose is to achieve a high thrust level required for space missions with less input power than with self-field MPD thrusters and thus avoid the onset instabilities. For the verification of the code, the NASA Lewis Research Center's (NASALeRC) MPD thruster is chosen because of its wide range of experimental data bank. The method presented reproduce the theory of thrust production and plasma acceleration. Some difficulties as the limitation of the maximum rotational speed and the depletion of the plasma density on the anode surface have been captured. Moreover, the present density-based method compares very well with experimental data of Myers and simulations of Mikellides