Pathways for sustainable technology development : The case of bicycle mobility in Berlin

Sustainability requires that quality of life and resource consumption are harmonized. The use of sustainable technologies fosters their harmonization. A scenario based method has been developed for identifying sustainable technology systems on different levels of development and in different areas of human living. The developed method consists of four elements: the surrounding field scenarios, technology pool, sustainability assessment and system creation. They can be applied in various paths with different starting points. The two technology induced paths, emanating from either a system or a system element, enable the transformation of technological potentials into useful applications. The problem induced path, emanating from future framework conditions of an observed field, allows human needs to be satisfied trough technological potentials. The application shown in this paper illustrates the usage of the method's problem induced path in mobility as one area of human living. Based on three surrounding field scenarios for bicycle mobility in Berlin, technology systems for bicycle design, operation and their repair in self-help workshops are illustrated

Procedure for Experiential Learning to Conduct Material Flow Simulation Projects, Enabled by Learning Factories

Material flow simulation is a powerful tool to identify improvements in factory operation. For conducting simulation projects, experts are required who know how to prepare, execute and evaluate simulation studies. To date, training mostly focusses on textual case studies, whereby learners perform simulation studies based on a problem and data given in a description. However, this hardly reflects the ways engineers learn. They are mostly used to physically experiment based on their experience. In this paper, a procedure for experiential learning to conduct material flow simulation projects is elaborated, enabled by learning factories. A learning situation at Vietnamese-German University is described. Results indicate, that the students gain particular awareness about the challenges associated with the abstraction of the reality and the interpretation of the simulation outcomes

Language independent transfer of assembly knowledge

Transferring assembly knowledge for workers with different cultural and linguistic background is challenging. The established solution of translating written instructions into multiple languages is mostly cost intensive, holds a potential for mistakes and the result might be hard to understand. To cope with this challenge, three different assembly instructions with language reduced or language independent content have been tested in a study with students in Vietnam and Germany. The types of instructions were interactive 3D-PDF, Utility-Film and illustrated manual. Assembly errors, assembly time, safety symbol awareness and assembly sequences understanding are compared and evaluated based on students’ technical pre-knowledge and experience. The 3D-PDF showed to be the best solution to be applied in this complex environment, because users were able to assemble the parts faster and experienced a higher degree of interactivity compared to the other instructions

Supramolecular synthon pattern in solid clioquinol and cloxiquine (APIs of antibacterial, antifungal, antiaging and antituberculosis drugs) studied by 35Cl NQR, 1H-17O and 1H-14N NQDR and DFT/QTAIM

The quinolinol derivatives clioquinol (5-chloro-7-iodo-8-quinolinol, Quinoform) and cloxiquine (5-chloro-8-quinolinol) were studied experimentally in the solid state via 35Cl NQR, 1H-17O and 1H-14N NQDR spectroscopies, and theoretically by density functional theory (DFT). The supramolecular synthon pattern of O–H···N hydrogen bonds linking dimers and π–π stacking interactions were described within the QTAIM (quantum theory of atoms in molecules) /DFT (density functional theory) formalism. Both proton donor and acceptor sites in O–H···N bonds were characterized using 1H-17O and 1H-14N NQDR spectroscopies and QTAIM. The possibility of the existence of O–H···H–O dihydrogen bonds was excluded. The weak intermolecular interactions in the crystals of clioquinol and cloxiquine were detected and examined. The results obtained in this work suggest that considerable differences in the NQR parameters for the planar and twisted supramolecular synthons permit differentiation between specific polymorphic forms, and indicate that the more planar supramolecular synthons are accompanied by a greater number of weaker hydrogen bonds linking them and stronger π···π stacking interactions

Fertigung laminarer optischer Gitter am HZB

Laminare optische Gitter stellen höchste Anforderungen an die mikrosystemtechnische Fertigung der Mikro und Nano strukturen in Hinsicht auf Präzision und Homogenität. Im Rahmen des EU Projektes Aufbau eines Technologiezent rums für hocheffiziente optische Präzisionsgitter am Helmholtz Zentrum Berlin HZB EFRE Vertrag Nr. 20072013 2 43 [1,2] wurden die für die Herstellung von laminaren und geblazten Gittern notwendigen Anlagen in Betrieb ge nommen. Gleichzeitig wurde mit der Prozessentwicklung begonnen. In diesem Artikel werden die neuesten Prozessergebnisse von durch Laserinterferenzlithographie LIL in Photoresist erzeugter Gitterstrukturen und deren nur wenige Nanometer tiefe Übertragung in Siliziumsubstrate mittels Ionenstrahl ätzen vorgestellt. english version Laminar optical gratings impose highest demands on microsystem technological manufacturing with regard to precision and uniformity. Within the project Installation of a technology centre for highly efficient precision gratings at Helm holtz Zentrum Berlin HZB EFRE Vertrag Nr. 20072013 2 43 [1,2] the necessary systems for the manufacturing of laminar and blazed gratings were taken into operation and process development has started. In this article we present the results of grating structures manufactured with laser interference lithography and subse quent ion beam etchin

Cardiac Biomarkers and Risk of Atrial Fibrillation in Chronic Kidney Disease: The CRIC Study.

Background We tested associations of cardiac biomarkers of myocardial stretch, injury, inflammation, and fibrosis with the risk of incident atrial fibrillation (AF) in a prospective study of chronic kidney disease patients. Methods and Results The study sample was 3053 participants with chronic kidney disease in the multicenter CRIC (Chronic Renal Insufficiency Cohort) study who were not identified as having AF at baseline. Cardiac biomarkers, measured at baseline, were NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity troponin T, galectin-3, growth differentiation factor-15, and soluble ST-2. Incident AF ("AF event") was defined as a hospitalization for AF. During a median follow-up of 8 years, 279 (9%) participants developed a new AF event. In adjusted models, higher baseline log-transformed NT-proBNP (N-terminal pro-B-type natriuretic peptide) was associated with incident AF (adjusted hazard ratio [HR] per SD higher concentration: 2.11; 95% CI, 1.75, 2.55), as was log-high-sensitivity troponin T (HR 1.42; 95% CI, 1.20, 1.68). These associations showed a dose-response relationship in categorical analyses. Although log-soluble ST-2 was associated with AF risk in continuous models (HR per SD higher concentration 1.35; 95% CI, 1.16, 1.58), this association was not consistent in categorical analyses. Log-galectin-3 (HR 1.05; 95% CI, 0.91, 1.22) and log-growth differentiation factor-15 (HR 1.16; 95% CI, 0.96, 1.40) were not significantly associated with incident AF. Conclusions We found strong associations between higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity troponin T concentrations, and the risk of incident AF in a large cohort of participants with chronic kidney disease. Increased atrial myocardial stretch and myocardial cell injury may be implicated in the high burden of AF in patients with chronic kidney disease

Action functionals for relativistic perfect fluids

Action functionals describing relativistic perfect fluids are presented. Two of these actions apply to fluids whose equations of state are specified by giving the fluid energy density as a function of particle number density and entropy per particle. Other actions apply to fluids whose equations of state are specified in terms of other choices of dependent and independent fluid variables. Particular cases include actions for isentropic fluids and pressureless dust. The canonical Hamiltonian forms of these actions are derived, symmetries and conserved charges are identified, and the boundary value and initial value problems are discussed. As in previous works on perfect fluid actions, the action functionals considered here depend on certain Lagrange multipliers and Lagrangian coordinate fields. Particular attention is paid to the interpretations of these variables and to their relationships to the physical properties of the fluid.Comment: 40 pages, plain Te

A comparative study of the hydrogen-bonding patterns and prototropism in solid 2-thiocytosine (potential antileukemic agent) and cytosine, as studied by 1H-14N NQDR and QTAIM/ DFT

A potential antileukemic and anticancer agent, 2-thiocytosine (2-TC), has been studied experimentally in the solid state by 1H-14N NMR-NQR double resonance (NQDR) and theoretically by the quantum theory of atoms in molecules (QTAIM)/density functional theory (DFT). Eighteen resonance frequencies on 14N were detected at 180 K and assigned to particular nitrogen sites (−NH2, –N=, and –NH–) in 2-thiocytosine. Factors such as the nonequivalence of molecules (connected to the duplication of sites) and possible prototropic tautomerism (capable of modifying the type of site due to proton transfer) were taken into account during frequency assignment. The result of replacing oxygen with sulfur, which leads to changes in the intermolecular interaction pattern and molecular aggregation, is discussed. This study demonstrates the advantages of combining NQDR and DFT to extract detailed information on the H-bonding properties of crystals with complex H-bonding networks. Solid-state properties were found to have a profound impact on the stabilities and reactivities of both compounds

A Variational Procedure for Time-Dependent Processes

A simple variational Lagrangian is proposed for the time development of an arbitrary density matrix, employing the "factorization" of the density. Only the "kinetic energy" appears in the Lagrangian. The formalism applies to pure and mixed state cases, the Navier-Stokes equations of hydrodynamics, transport theory, etc. It recaptures the Least Dissipation Function condition of Rayleigh-Onsager {\bf and in practical applications is flexible}. The variational proposal is tested on a two level system interacting that is subject, in one instance, to an interaction with a single oscillator and, in another, that evolves in a dissipative mode.Comment: 25 pages, 4 figure