Investigation of the changes in physical properties of PES/PVC fabrics after aging

The aim of this work was to investigate the physical and mechanical performance of architectural polyester (PES)–poly(vinyl chloride) (PVC) membranes exposed to different artificial aging conditions. Two commercially available architectural membranes were chosen as research objects. The durability of the PES/PVC fabrics was evaluated by the loss in mechanical performance, scanning electron microscopy, and X-ray diffraction analysis in order to understand the effect of the degradation agents on the surface of the membranes. The mechanical performance of the PES/PVC membranes was unchanged. Scanning electron microscopy images of the tested materials showed initial cracks after aging. The X-ray fluorescence analysis showed that at the time of aging, the amount of Cl and Si decreased slightly, while Ti decreased by half, and Ca by volume increased twice. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47523.     

Laser coupling to single-mode fibre using graded-index lenses and compact disc 1.3 ?m laser package

A 1.3 ?m laser in a compact disc package is coupled to single-mode fibre using two graded-index lenses in a nearly confocal scheme. An increase in the alignment tolerance at the lens-lens interface by a factor of six suggests the design for a potentially very low-cost connectorised laser package. The coupling efficiency of approx. 6% (?12 dB) is shown to be adequate for local loop applications.     

A modern workflow for force-field development – Bridging quantum mechanics and atomistic computational models

In this article we present our recent efforts in designing a comprehensive consistent scientific workflow, nicknamed Wolf₂ Pack, for force-field optimization in the field of computational chemistry. Atomistic force fields represent a multiscale bridge that connects high-resolution quantum mechanics knowledge to coarser molecular mechanics-based models. Force-field optimization has so far been a time-consuming and error-prone process, and is a topic where the use of a scientific workflow can provide obvious great benefits. As a case study we generate a gas-phase force field for methanol using Wolf₂ Pack, with special attention given toward deriving partial atomic charges.     

Rotationally controlled magneto-hydrodynamic particle handling for bead-based microfluidic assays

This work presents a novel magnetic actuation scheme for advanced particle handling on our previously introduced, centrifugal microfluidic platform for array-based analysis of individual cells and beads. The conceptually simple actuation is based on the reciprocating motion of an elastomeric membrane featuring an integrated permanent magnet and a stationary magnet aligned along the orbit of a disc-based chamber. This compression chamber is placed at the downstream end of the particle capture chamber to induce centripetally directed, hydrodynamic lift forces on particles trapped in V-shaped geometrical barriers. Towards high frequencies of rotation, the on-disc magnet ceases to follow the rapidly oscillating magnetic field, so that the magnetic actuator is disabled during the initial, sedimentation-based filling of the trap array. At reduced spin speeds, the residence time of the magnetic actuator is sufficient to displace the magnetic actuator, resulting in a flow through the V-cup array that re-distributes, and eventually fully depletes, the previously trapped beads from the array. The same magnetic deflection scheme is also demonstrated to accelerate mixing, e.g. for upstream sample preparation.     

Transport measurements on microcrystals of oriented CeIn3 and CeCoIn5 thin films

We present results of a systematic growth study on the substrate temperature-driven de-wetting of CeIn₃ thin films as a reference compound for the heavy-fermion superconductor CeCoIn₅. This study is motivated by the last results on the improved surface morphology and in-plane orientation preference of c-axis oriented CeCoIn₅ thin films. In apparently phase pure CeIn₃ thin films, as far as x-ray diffraction can tell, we find evidence for minor In segregation by means of percolating resistance contributions of In in the films. We argue that further efforts into improving the films' morphology towards optimized surfaces for the preparation of macroscopic planar tunnel junctions may be futile. As an alternative approach, we present results of electronic transport measurements on CeIn₃ and CeCoIn₅ microcrystals isolated from the thin films by means of focused particle beam induced processing, such as focused ion beam milling and deposition.     

Integrating resource criticality assessment into evaluation of cleaner production possibilities for increasing resource efficiency

A stable and secure source of raw materials is the key to any successful industrial activity. Resource criticality is often discussed in the context of the impact on the economies of certain geographic regions. However, the availability of required resources first of all concerns the competitiveness of industrial companies, especially in those countries which do not possess abundant natural resources. The Lithuanian economy relies heavily on imports since the country does not have abundant natural resources. The paper introduces resource criticality as an additional dimension for evaluating and prioritizing resource efficiency improvement options. Evaluation of resource criticality was integrated into the methodology for evaluation of Cleaner Production. Simple additive weighting (SAW) was used to solve the multi-criteria decision-making problem. The previous study on the natural resources that are imported to Lithuania revealed that metals are among the most important raw materials in terms of economic importance, supply, and environmental risks. Therefore, a typical metal processing company in Lithuania was selected for the detailed investigation of technological processes and Cleaner Production possibilities. The selected company processes about 3000 tons of various metals per year. The results of Process Material Flow Analysis show that most of the metal waste is generated during the metal plate cutting process (about 30.3 % of total metal consumption). Three resource efficiency improvement alternatives were evaluated and compared. The suggested decision support system was tested in order to decide on a definitive solution. The results reveal that evaluation of resource criticality in terms of geostrategic supply risk and economic importance can be used as an advantageous criterion to support the prioritization of Cleaner Production alternatives.     

Performance of 4*4 optical crossbar switch utilising acousto-optic deflector

A multicasting photonic space switch reconfigurable in 50 ns is demonstrated utilising commercially available acousto-optic Bragg cells at lambda =0.83 mu m. Insertion loss of 15 dB, extinction ratio of 33 dB, crosstalk of -24 dB and polarisation difference of 0.8 dB are reported.<>     

Microchips for the Investigation of Thermal and Electrical Properties of Individual Nanowires

This paper focuses on the determination of thermal and electrical properties of individual thermoelectric nanowires, primarily bismuth and bismuth compound nanowires, as functions of their crystallinity, diameter, and composition. For measurements of the Seebeck coefficient and the electrical and thermal conductivity, specially designed microchips have been developed and employed. Finite-element simulations demonstrate that the temperature profiles of the microchips provide suitable temperature gradients for Seebeck-effect measurements and heat-sink conditions for thermal conductivity investigations. First measurements of thermal conductivity of metallic nanowires and of Seebeck coefficients of granular nanowires prepared by focused electron-beam-induced deposition are presented. Some of these results are discussed in the framework of finite-size-effect theory.     

Utilization of electroplating to lock fibers for use in opticaldevice packaging

An electroplating technique for permanently fixing single-mode fibers into position in optical device packages is described. In this technique, the fiber is mounted in a metal tube and aligned to an optical device mounted on a metal substrate. The fiber is in close proximity to the substrate and a flexible conductive gel is used to connect the two electrically. The fiber, gel, and substrate thus form the plating cathode. When immersed in a plating bath with an anode inserted, metal can be deposited across the gel, forming a strong metal bridge between the fiber and substrate, locking the fiber into position. Under appropriate conditions, misalignments within ±1 μm during the plating process have been observed. This technique was used to package a laser diode transmitter, which locked the laser-to-fiber alignment to within 0.7 μm, or 0.1 dB of the optimum coupled power