High-temperature deformation behavior of a gamma TiAl alloy-microstructural evolution and mechanisms

The present investigation was carried out in the context of the internal-variable theory of inelastic deformation and the dynamic-materials model (DMM), to shed light on the high-temperature deformation mechanisms in TiAl. A series of load-relaxation tests and tensile tests were conducted on a fine-grained duplex gamma TiAl alloy at temperatures ranging from 800 degreesC to 1050 degreesC. Results of the load-relaxation tests, in which the deformation took place at an infinitesimal level (epsilon congruent to 0.05), showed that the deformation behavior of the alloy was well described by the sum of dislocation-glide and dislocation-climb processes. To investigate the deformation behavior of the fine-grained duplex gamma TiAl alloy at a finite strain level, processing maps were constructed on the basis of a DMM. For this purpose, compression tests were carried out at temperatures ranging from 800 degreesC to 1250 degreesC using strain rates ranging from 10 to 10(-4)/s. Two domains were identified and characterized in the processing maps obtained at finite strain levels (0.2 and 0.6). One domain was found in the region of 980 degreesC and 10(-3)/s with a peak efficiency (maximum efficiency of power dissipation) of 48 pct and was identified as a domain of dynamic recrystallization (DRx) from microstructural observations. Another domain with a peak efficiency of 64 pct was located in the region of 1250 degreesC and 10(-4)/s and was considered to be a domain of superplasticity.ope

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Dual functional membrane capable of both visual sensing and blocking of waterborne virus

Norovirus, which is transmitted by contact with a contaminated object or person who has a norovirus infection, eating contaminated food, or drinking contaminated water, is a highly contagious virus for humans and animals. Among many infection routes, water supply systems from reservoirs or dams become very important due to the possibility of mass infection. Because only a small amount of norovirus (10–100 particles forming unit) can cause the infection, a rapid and easy detection of the virus is required. Once norovirus is detected, the water supply should be quickly shut down. Here, we introduce a dual functional membrane capable of both easy detecting with the naked eye and blocking noroviruses. We employed an anodized aluminum oxide (AAO) membrane with uniform pores. The top and bottom parts of the membrane were grafted with polydiacetylene (PDA) and poly(N-isopropylacrylamide) (PNIPAM), respectively. The top part was further bioconjugated by antibody for feline calicivirus (FCV), which is a model virus whose structure is similar to norovirus. The membrane showed color change from blue to red when the FCVs were attached to the antibodies. Water flux was controlled (turned on and off) by changing water temperature by using the well-known thermosensitive property of PNIPAM chains. On and off control of water flow was quickly established (less than 5 s) when a laser with near infrared (NIR) wavelength was turned on and off, respectively. In addition, the membrane completely blocked the virus influx into the water system by antibody binding before visual sensing followed by flow control. © 2017 Elsevier B.

Fibre-bulk hybrid lasers - Recent developments and future prospects

Cladding-pumped fibre lasers are becoming increasingly attractive for high power generation due to their high efficiency and immunity from thermal effects. However, due to their small core size and long device length, pulse energies are rather limited. In contrast, conventional 'bulk' solid-state lasers offer the prospect of much higher pulse energies, but suffer from detrimental thermal effects which can degrade beam quality and efficiency. An alternative strategy for scaling output power and pulse energy, which is attracting growing interest, is to use a hybrid laser scheme. In this approach, the fibre laser is used as a high-brightness source for in-band pumping of a bulk solid-state laser. One of the main attractions of the fiber-bulk hybrid laser scheme is that most of the heat generated via quantum defect heating is deposited in the fibre, and thermal effects in the bulk laser are dramatically reduced leading to the prospect of much improved efficiency, beam quality, higher average output power and high pulse energy. This approach has already been successfully applied to a number of different solid-state lasers operating in the eyesafe wavelength regimes around 1.6 μm and 2 μm. This presentation will review recent progress in power scaling of hybrid lasers in cw and in pulsed modes of operation, and will consider the prospects for further improvement in performance.</p

Poly(Amido Amine)s containing agmatine and butanol side chains as efficient gene carriers

A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of ABOL in the side chains have shown to improve the overall transfection efficiency of poly(amido amine)s, it is hypothesized that poly(CBA-ABOL/AGM) synthesized at the optimal ratio of both components would result in high transfection efficiency and minimal toxicity. In this study, a series of the poly(CBA-ABOL/AGM) copolymers is synthesized as gene carriers. The polymers are characterized and luciferase transfection efficiencies of the polymers in various cell lines are investigated to select the ideal ratio between AGM and ABOL. The poly(CBA-ABOL/AGM) containing 80% AGM and 20% ABOL has shown the best transfection efficiency with the lowest cytotoxicity, indicating that this polymer is very promising as a potent and nontoxic gene carrie

Crystal structure and thermoelectric performance of p–type Bi0.86Ba0.14CuSeO/Cu2–ySe composites

Bi0.86Ba0.14CuSeO/xCu2–ySe (0.05 ≤ x ≤ 0.15; y = 0 and 0.2) composites were fabricated by spark plasma sintering, and the crystal structure and thermoelectric properties of the Bi0.86Ba0.14CuSeO/xCu2–ySe composites were studied. The composites contained Cu2–ySe (y = 0 and 0.2) nanoinclusions in a tetragonal Bi0.86Ba0.14CuSeO matrix. To increase the electrical conductivities of Bi0.86Ba0.14CuSeO, we introduced Cu2–ySe nanoinclusions with a high electrical conductivity into the matrix. The introduction of Cu2–ySe nanoinclusions reduced the structural distortion of CuSe4 tetrahedra and the effective mass, thereby enhancing the carrier mobility. A significant increase in electrical conductivities was achieved with increasing Cu2–ySe nanoinclusion, i.e., 117, 165, and 214 Ω−1cm−1 at 673 K for x = 0.05, 0.10, and 0.15 composites. The Cu2–ySe nanoinclusions reduced the lattice thermal conductivity because they strengthened the long–wavelength phonon scattering at the Bi0.86Ba0.14CuSeO/Cu2–ySe interface. The largest dimensionless figure–of–merit (0.33 at 673 K) was obtained for x = 0.15 composite, which was attributed to the highest electrical conductivity and the lowest lattice thermal conductivity