Scintillation Calorimetry and Readout Techniques

The status and prospects of new scintillation materials for calorimetry applications in high energy physics are reviewed. New readout methods are discussed with emphasis on the operation of high resolution scintillation calorimeters in magnetic fields.     

Fast preparation of biopassive nonfouling coatings on cellulose

The microbial infection as a result of biofilm formation is a serious problem in various fields of application in the paper industry including fouling of filters in air conditioning systems, wallpaper, medical and food packaging as well as ancient documents. In this study, we document a highly nonfouling surface coating formed by a functional copolymer consisting of 2-methacryloyloxyethyl phosphorylcholine, as a zwitterionic and cell repellent component, and 4-benzophenyl methacrylate, acting as an anchor group for a fast UV-induced persistent covalent attachment on thin cellulose model films deposited on silicon wafers. The grafting process, studied by UV–Vis spectroscopy, is much faster in comparison with common grafting-to techniques. The obtained sustainable and nonleaching surface coatings were analyzed by attenuated total reflectance-Fourier transform infrared spectroscopy, contact angle measurements, spectroscopic in situ ellipsometry, and atomic force microscopy. Incubation of the modified cellulose surfaces with either Escherichia coli, Bacillus subtilis or Saccharomyces cerevisiae demonstrates that the zwitterionic polymer functionalization has substantial nonfouling capacity against both Gram-negative and Gram-positive bacteria as well as the yeast fungus.     

Electrode effects in the sweeping of alpha quartz

Experimental observations are described in the air-sweeping of alpha-quartz that reveal the introduction of hydrogen. Porous electrodes facilitate the indiffusion of hydrogen. By contrast, the use of thick, nonporous, strongly adherent Au/Cr electrodes causes a color-center front to advance from anode to cathode. Evidence is presented that indicates that: (1) color centers form beneath nonporous portions of the anode that correlate with the formation of Cr(2)O(3) on the metal surface and Cr-silicides at the metal-quartz interface, and (2) large-diameter clear striae form along the c-axis that correlate with small openings in the anode. These observations suggest that: (1) openings in the anode metallization are required for hydrogen introduction; (2) the electrochemical charge-transfer reaction, leading to hydrogen introduction, occurs at the gas-electrode-quartz boundary and spreads laterally by interfacial diffusion of hydrogen species; and (3) color centers form through the suppression of interfacial H-diffusion. Additionally, electrode-surface damage and high electric fields can result in undesirable electrode-metal indiffusion.     

Testing of timber structures and building boards

RILEM Recommendations57-TSB RILEM/CIB Joint Technical Committee

Testing of timber structures and building boards     

Surface functionalization by smart coatings: Stimuli-responsive binary polymer brushes

Heterogeneous binary polymer brushes consist of an assembly of polymer chains of two incompatible polymers that are attached by one end to the surface with sufficient grafting density. They have been investigated experimentally only for a short time. Those brushes can be used in the form of ultrathin polymeric layers as a versatile tool for surface engineering to tune physico-chemical surface characteristics as wettability, surface charge, chemical composition or morphology, and furthermore to create switchable and responsive surface properties. For the fabrication of these layers “grafting-from” (as radical polymerization at the interface) and “grafting-to” (as tethering of the polymer chains from solution) methods were developed and investigated in detail.     

A Cubic-Vertex Kernel for Flip Consensus Tree

Given a bipartite graph G=(V _c ,V _t ,E) and a nonnegative integer k, the NP-complete Minimum-Flip Consensus Tree problem asks whether G can be transformed, using up to k edge insertions and deletions, into a graph that does not contain an induced P ₅ with its first vertex in V _t (a so-called M-graph or Σ-graph). This problem plays an important role in computational phylogenetics, V _c standing for the characters and V _t standing for taxa. Chen et al. (IEEE/ACM Trans. Comput. Biol. Bioinform. 3:165–173, 2006). showed that Minimum-Flip Consensus Tree is NP-complete and presented a parameterized algorithm with running time O(6 ^k ?|V _t |?|V _c |). Subsequently, Böcker et al. (ACM Trans. Algorithms 8:7:1–7:17, 2012) presented a refined search tree algorithm with running time O(4.42 ^k (|V _t |+|V _c |)+|V _t |?|V _c |). We continue the study of Minimum-Flip Consensus Tree parameterized by k. Our main contribution are polynomial-time executable data reduction rules yielding a problem kernel with O(k ³) vertices. In addition, we present an improved search tree algorithm with running time O(3.68 ^k ?|V _c |²|V _t |).     

Metallurgical interactions at the contacts GaAs interface

Interface morphology, phase composition, and elemental diffusion of Pt/Ti/Ge/Pd ohmic contacts to both n and p⁺-GaAs have been investigated as a function of annealing temperature. Structural and chemical results were correlated with specific contact resistances (ρ_c) measured for each thermal treatment. Annealing at 450°C yielded the lowest ρ_c, ～6.4 × 10^?7Ω-cm². The interface was observed to be smooth and abrupt. Two interface phases were detected; a primary phase, PdGe, and a secondary, Ga-rich Pd-Ga-As ternary phase. The presence of this ternary phase was found to be critical to contact formation on n-GaAs. The Ti and Pt layers remained pristine. Annealing at 550°C resulted in a slightly higher ρ_c, ～2.1 × 10^?6Ω-cm². There was significant elemental diffusion within the contact metal and minor diffusion into the GaAs substrate. The interface possessed limited areas of spiking with uniform composition. Annealing at 600°C proved to have a detrimental effect on the ρ_c, ～10^?4Ω-cm². This electrical degradation was accompanied by strong chemical intermixing between the contact and substrate, resulting in a continuous nonplanar interface with deep multiphase protrusions.     

The water–food–energy nexus: an introduction to nexus concepts and some conceptual and operational problems

This introduction sets the scene for the special issue compiled by Martin Keulertz, Eckart Woertz and Tony Allan.     

Influence of inclusion contents on the micro-machinability of three plastic mold steels

For the manufacturing of micro molds, usually, the same sort of materials is used as for conventional machining. However, phenomena that occur when the depth of cut approaches the cutting edge radius have to be considered. This paper presents experimental investigations on tool life tests of micromilling processes. TiAlN-coated cemented carbide tools are applied on three different mold steels for plastic injection molding. The influences of two different types of inclusions are explored on tool wear, cutting forces, chip formation, burr formation, and surface finishing of the machined specimens.