Simulation strategies for the massless lattice Schwinger model in the dual formulation

The dual form of the massless Schwinger model on the lattice overcomes the complex action problems from two sources: a topological term, as well as non-zero chemical potential, making these physically interesting cases accessible to Monte Carlo simulations. The partition function is represented as a sum over fermion loops, dimers and plaquette-surfaces such that all contributions are real and positive. However, these new variables constitute a highly constrained system and suitable update strategies have to be developed. In this exploratory study we present an approach based on locally growing plaquette-surfaces surrounded by fermion loop segments combined with a worm based strategy for updating chains of dimers, as well as winding fermion loops. The update strategy is checked with conventional simulations as well as reference data from exact summation on small volumes and we discuss some physical implications of the results

Organizational Water Footprint to Support Decision Making: a Case Study for a German Technological Solutions Provider for the Plumbing Industry

With water scarcity representing an increasing threat to humans, the environment and the economy, companies are interested in exploring how their operations and supply chains affect water resources globally. To allow for systematically compiling the water footprint at the company level, the organizational water footprint method based on ISO 14046 and ISO/TS 14072 was developed. This paper presents the first complete organizational water scarcity footprint case study carried out for Neoperl GmbH, a German company that offers innovative solutions regarding drinking water for the plumbing industry. The cradle-to-gate assessment for one year includes, besides facility-based production activities, purchased materials, electricity and fuels, and supporting activities, such as company vehicles and infrastructure. Neoperl’s total freshwater consumption amounts to approximately 110,000 m3, 96% thereof being attributable to the supply chain, with freshwater consumption through purchased metals playing the predominant role. Metals (mainly stainless steel and brass) are major hotspots, also when considering the water scarcity-related local impacts resulting from freshwater consumption, which mainly affect China and Chile. These results can be used to improve the company’s supply chain water use in cooperation with internal and external stakeholders by means of, e.g., sustainable purchase strategies or eco-design options to substitute water intensive materials.BMBF, 02WGR1429, GROW - Verbundprojekt WELLE: Wasserfußabdruck für Unternehmen - Lokale Maßnahmen in Globalen WertschöpfungskettenDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

Increase of the mean inner Coulomb potential in Au clusters induced by surface tension and its implication for electron scattering

Electron holography in a transmission electron microscope was applied to measure the phase shift induced by Au clusters as a function of the cluster size. Large phase shifts Df observed for small Au clusters cannot be described by the well-known equation Df=C_E V_0 t (C_E: interaction constant, V_0: mean inner Coulomb potential (MIP) of bulk gold, t: cluster thickness). The rapid increase of the Au MIP with decreasing cluster size derived from Df, can be explained by the compressive strain of surface atoms in the cluster

Development of a ³He magnetometer for a neutron electric dipole moment experiment

We have developed a highly sensitive 3He magnetometer for the accurate measurement of the magnetic field in an experiment searching for an electric dipole moment of the neutron. By measuring the Larmor frequency of nuclear spin polarized 3He atoms a sensitivity on the femto-Tesla scale can be achieved. A 3He/Cs-test facility was established at the Institute of Physics of the Johannes Gutenberg University in Mainz to investigate the readout of 3He free induction decay with a lamp-pumped Cs magnetometer. For this we designed and built an ultra-compact and transportable polarizer unit which polarizes 3He gas up to 55% by metastability exchange optical pumping. The polarized 3He was successfully transfered from the polarizer into a glass cell mounted in a magnetic shield and the 3He free induction decay was detected by a lamp-pumped Cs magnetometer.PACS numbers07.55.Ge Magnetometers for magnetic field measurements; 13.40 Electric and magnetic moments; 14.20 Protons and neutrons

High glucose disrupts oligosaccharide recognition function via competitive inhibition : a potential mechanism for immune dysregulation in diabetes mellitus

Diabetic complications include infection and cardiovascular disease. Within the immune system, host-pathogen and regulatory host-host interactions operate through binding of oligosaccharides by C-type lectin. A number of C-type lectins recognise oligosaccharides rich in mannose and fucose – sugars with similar structures to glucose. This raises the possibility that high glucose conditions in diabetes affect protein-oligosaccharide interactions via competitive inhibition. Mannose binding lectin, soluble DC-SIGN & DC-SIGNR, and surfactant protein D, were tested for carbohydrate binding in the presence of glucose concentrations typical of diabetes, via surface plasmon resonance and affinity chromatography. Complement activation assays were performed in high glucose. DC-SIGN and DC-SIGNR expression in adipose tissues was examined via immunohistochemistry. High glucose inhibited C-type lectin binding to high-mannose glycoprotein and binding of DC-SIGN to fucosylated ligand (blood group B) was abrogated in high glucose. Complement activation via the lectin pathway was inhibited in high glucose and also in high trehalose - a nonreducing sugar with glucoside stereochemistry. DC-SIGN staining was seen on cells with DC morphology within omental and subcutaneous adipose tissues. We conclude that high glucose disrupts C-type lectin function, potentially illuminating new perspectives on susceptibility to infectious and inflammatory disease in diabetes. Mechanisms involve competitive inhibition of carbohydrate-binding within sets of defined proteins, in contrast to broadly indiscriminate, irreversible glycation of proteins

Investigation of CO2 avoidance behaviour of membrane capture in post combustion processes

Increasing concern for the environment and taxes on carbon dioxide emissions has intensified the development of non-polluting energy supply technologies. Carbon Capture and Storage (CCS) constitute a promising option that can reduce CO2 emissions significantly. State-of-the-art CO2 capture techniques require very high investment costs which will lead to a substantial drop in power plant efficiency. This thesis focuses on energetic and economical investigations of gas separation membrane systems used for post-combustion capture in coal fired power plants. The simulations were carried out with the commercial software packages PRO/II and Aspen Plus. A reference power plant termed the Reference Power Plant North Rhine-Westphalia was chosen for the analyses. On the basis of two membrane cascades, developed by using an ideal flue gas of CO2 and N2, the investigation was carried out using a quasi real flue gas, composed of CO2, N2, O2, H2O and Ar. Although the water content in the flue gas leads to higher energy consumption, a positive effect can be observed: using the same membrane area as in the case with ideal flue gas, the degree of CO2 separation is increased owing to the sweep gas effect of the water content. A detailed heat exchanger investigation was explored for a chosen cascade. The aim was to ensure that the recovered exhaust heat generated from the compression process is sufficient to reheat the retentate in the expansion process. A modification distinguished from the ideal flue gas system was to keep the pressure ratio constant for each pressure section. This makes it possible to have a uniform intercooler design for each stage. A pressure drop of 30 mbar inside each cooler was investigated. This extensive system design results in an energy demand of 292 kWh/tonseparated CO2, a separation degree of 78% and an efficiency loss of 7.9%-points. The system has an energetic advantage in comparison with the MEA absorption method at the same degree of CO2 separation. On the basis of the reference power plant, a comprehensive economic analysis was made, both for CO2 capture cost and CO2 avoidance cost. The results manifest that the heat exchanger cost has a small influence on the total capture cost, which is dominated by the membrane cost in the process. A probable future CO2 emission policy was considered and the CO2 emission cost was included in the calculation. By evaluating the electricity price of the different cases (the reference power plant, the chosen cascade for CO2 capture and the chosen cascade for CO2 avoidance), it was found that high CO2 permeance membranes with long life time and a cheap manufacturing price should be developed to make membrane capture systems more economically competing