Dual Side Research Articles

Dissimilar spot welding of dual phase steel/ferritic stainless steel: phase transformations

Phase transformations in dissimilar resistance spot welds of dual phase steel and ferritic stainless steel are analysed. In contrast to a full martensitic microstructure predicted by the Schaeffler and Balmforth diagrams, a ferrite–martensite microstructure was observed in the fusion zone. The formation of ferrite phase in the fusion zone can be attributed to the rapid cooling rate of resistance spot welding, which suppresses the post-solidification ferrite–austenite transformation. The grain growth and martensite formation were main metallurgical features of the heat affected zone of ferritic stainless steel side. Microstructure gradient of heat affected zone in dual phase steel side was dictated by martensitic transformation. The effect of weld thermal cycle on the mechanical performance of the joint is discussed.

Generalized phase transitions in Lovelock gravity

We investigate a novel mechanism for phase transitions that is a distinctive feature of higher-curvature gravity theories. For definiteness, we bound ourselves to the case of Lovelock gravities. These theories are known to have several branches of asymptotically anti--de Sitter solutions. Here, extending our previous work, we show that phase transitions among some of these branches are driven by a thermalon configuration: a bubble separating two regions of different effective cosmological constants, generically hosting a black hole in the interior. Above some critical temperature, this thermalon configuration is preferred with respect to the finite-temperature anti--de Sitter space, triggering a sophisticated version of the Hawking-Page transition. After being created, the unstable bubble configuration can in general dynamically change the asymptotic cosmological constant. While this phenomenon already occurs in the case of a gravity action with square curvature terms, we point out that in the case of Lovelock theory with cubic (and higher) terms new effects appear. For instance, the theory may admit more than one type of bubble and branches that are in principle free of pathologies may also decay through the thermalon mechanism. We also find ranges of the gravitational couplings for which the theory becomes sick. These add up to previously found restrictions to impose tighter constraints on higher-curvature gravities. The results of this paper point to an intricate phase diagram which might accommodate similarly rich behavior in the dual conformal field theory side.

Dissimilar Metal Active Gas Welding of TWIP and DP Steel Sheets

In the last years, TWIP steels have been proposed for the fabrication of car‐body components, due to their excellent combination of strength and toughness. However, a widespread usage of these steels for such applications is conditional on the employment of dissimilar welding with other automotive high‐strength steel grades. In this study, dissimilar butt weld seams of TWIP and Dual Phase steel sheets fabricated by metal active gas welding are examined. The microstructural and mechanical characterization of the welded joints were carried out by optical metallography, microhardness, tensile testing, and fractographic examination. The heat affected zone on the TWIP side was fully austenitic and the only detectable effect was grain coarsening; on the dual phase side new martensite formed close to the fusion zone, while ferrite, and tempered martensite occurred away from the fusion zone. The welded tensile specimens exhibit a plastic behavior influenced by the TWIP steel, even though with more limited tensile strengths and elongation at fractures. The tensile specimens predominantly broke within the weld seams, with the fractures surfaces being ductile.

Laminated carbon nanotube networks for metal electrode-free efficient perovskite solar cells.

Organic-inorganic metal halide perovskite solar cells were fabricated by laminating films of a carbon nanotube (CNT) network onto a CH3NH3PbI3 substrate as a hole collector, bypassing the energy-consuming vacuum process of metal deposition. In the absence of an organic hole-transporting material and metal contact, CH3NH3PbI3 and CNTs formed a solar cell with an efficiency of up to 6.87%. The CH3NH3PbI3/CNTs solar cells were semitransparent and showed photovoltaic output with dual side illuminations due to the transparency of the CNT electrode. Adding spiro-OMeTAD to the CNT network forms a composite electrode that improved the efficiency to 9.90% due to the enhanced hole extraction and reduced recombination in solar cells. The interfacial charge transfer and transport in solar cells were investigated through photoluminescence and impedance measurements. The flexible and transparent CNT network film shows great potential for realizing flexible and semitransparent perovskite solar cells.

Can a stationary Bianchi black brane have momentum along the direction with no translational symmetry?

Bianchi black branes (black brane solutions with homogeneous but anisotropic horizons classified by the Bianchi type) provide a simple holographic setting with lattice structures taken into account. In the case of holographic superconductor, we have a persistent current with lattices. Accordingly, we expect that in the dual gravity side, a black brane should carry some momentum along a direction of lattice structure, where translational invariance is broken. Motivated by this expectation, we consider whether — and if possible, in what circumstances — a Bianchi black brane can have momentum along a direction of no-translational invariance. First, we show that this cannot be the case for a certain class of stationary Bianchi black brane solutions in the Einstein-Maxwell-dilation theory. Then we also show that this can be the case for some Bianchi VII0 black branes by numerically constructing such a solution in the Einstein-Maxwell theory with an additional vector field having a source term. The horizon of this solution admits a translational invariance on the horizon and conveys momentum (and is “rotating” when compactified). However this translational invariance is broken just outside the horizon. This indicates the existence of a black brane solution which is regular but non-analytic at the horizon, thereby evading the black hole rigidity theorem.

用于光束整形的表面等离子体双光栅结构

To shape the beam with two-lobe far-field property from a dual side Bragg reflection waveguide semiconductor laser, a dual grating structure based on surface plasmons was prepared on the optical outlet facet of a Bragg reflection waveguide. It could combine the two lobes into a single lobe and to increase the optical intensity and quality of the beam. An Au-SiO2 grating was used to couple photons into surface plasmons and to combine the two lobe beams into a single beam. The surface plasmons also were taken to increase the extraordinary optical transmission. On the other hand, the Au-Si3N4 grating was used to help the outlet surface plasmons couple back to photons, meanwhile collimating the outlet beam to increase the far-field property. Numerical simulation results indicate when the parameters for Au-SiO2 show a depth of 50 nm, a filling factor of 0.5 and a duration of 350 nm, and those for Au-Si3N4 show 70, 0.5 and 660 nm, respectively, the outlet far-field beam will has a 6.1 divergence, which means the divergence angle shrinks by 3.6 times as that without the dual grating structure. The far-field optical transmission power reaches 62% of the model source, that is 1.59 times of the power of a single lobe far-field to the structure without the dual grating. Moreover, the cavity facet reflectivity has reduced to 12.4%, 0.53 times as the structure without the dual grating. It concludes that the dual grating structure has optimized the far field properties of dual side Bragg reflection waveguide semiconductor lasers.

Thermalization and Black Holes

In the framework of AdS/CFT correspondence, we discuss how the thermalization in a Yang-Mills plasma is described by the exact solution of the time dependent black hole in the dual gravity side. We describe the prescription to match generic initial thermal states from the both sides. We also discuss implications of our solution on general non-equilibrium phenomena. The thermalization involves a loss of information leading to an increase of entropy, which is only possible in the thermodynamic limit of field theories. We argue that the large N limit plays a role of this thermodynamic limit in our AdS/CFT correspondence.

Thermalization of boosted charged AdS black holes by an ionic lattice

We investigate thermalization process of boosted charged AdS black holes in the Einstein-Maxwell system in the presence of an ionic lattice formed by spatially varying chemical potential. We calculate perturbations of the black holes by the lattice and investigate how the momentum relaxation occurs through umklapp scattering. In the WKB approximation, both of the momentum relaxation rate and entropy production rate are analytically obtained and the first law of black holes is derived in the irreversible process. Interestingly, both the analytical and numerical calculations show that the momentum relaxation rate or the entropy production rate does not approach zero in the zero temperature limit unless the velocity of the black hole is zero. In the dual field theory side, this indicates that persistent current does not exist even in the zero temperature limit, implying that the "ionic lattice" does not behave as a perfect lattice in a strongly coupled dual field theory.

The Placenta in Toxicology. Part IV

This review summarizes the potential and also some limitations of using human placentas, or placental cells and structures for toxicology testing. The placenta contains a wide spectrum of cell types and tissues, such as trophoblast cells, immune cells, fibroblasts, stem cells, endothelial cells, vessels, glands, membranes, and many others. It may be expected that in many cases the relevance of results obtained from human placenta will be higher than those from animal models due to species specificity of metabolism and placental structure. For practical and economical reasons, we propose to apply a battery of sequential experiments for analysis of potential toxicants. This should start with using cell lines, followed by testing placenta tissue explants and isolated placenta cells, and finally by application of single and dual side ex vivo placenta perfusion. With each of these steps, the relative workload increases while the number of feasible repeats decreases. Simultaneously, the predictive power enhances by increasing similarity with in vivo human conditions. Toxic effects may be detected by performing proliferation, vitality and cell death assays, analysis of protein and hormone expression, immunohistochemistry or testing functionality of signaling pathways, gene expression, transport mechanisms, and so on. When toxic effects appear at any step, the subsequent assays may be cancelled. Such a system may be useful to reduce costs and increase specificity in testing questionable toxicants. Nonetheless, it requires further standardization and end point definitions for better comparability of results from different toxicants and to estimate the respective in vivo translatability and predictive value.

Packet Loss Concealment Using Dual-Side Waveform Similarity Overlap-and-Add

Packet loss is one of the most essential problems in speech communication. It will cause the information loss and uncomfortable for listeners in voice over IP. This investment proposed an approach based on waveform similarity measure using overlap-and-Add algorithm. The waveform similarity overlap-and-add (WSOLA) technique is an effective algorithm to deal with packet loss concealment (PLC). For real-time time communication, the WSOLA algorithm is widely used to deal with the length adaptation and packet loss concealment of speech signal. Time scale modification of audio signal is one of the most essential research topics in data communication, especially in voice of IP (VoIP). Herein, we proposed the dual-side WSOLA that is derived by standard WSOLA. Instead of only exploitation one direction speech data, the proposed method will reconstruct the lost voice data according to the preceding and cascading voice. The dual-side WSOLA can use both the past and future speech signal waveform to reconstruction voice waveform of lost packet. The evaluations show that the quality of the reconstructed speech signal of the dual-side WSOLA is higher than that of the standard WSOLA and GWSOLA on different packet loss rate and length using the metrics: PESQ and MOS. The significant improvement is obtained by dual side information in the proposed method. The proposed dual-side waveform similarity overlap-and-add (DSWSOLA) outperforms the traditional approaches.

From Schurs to giants in ABJ(M)

In this work we consider various correlators with Schur polynomials in ABJ(M) models that on the dual gravity side should correspond to processes involving giant gravitons. Our analysis imposes several constraints on the physics of the probe branes on AdS4xCP3 as well as sheds more light on giant graviton solutions in this background with additional NS B-field. Our main tool is a formula that we derive for extremal n-point functions of the single trace chiral primary operators in the free field theory limit. The formula expresses the correlators in terms of the two-point function of Schur polynomials labeled by hook diagrams and is valid for a large class of gauge theories. In particular, in N = 4 SYM, it proves the conjecture of Beisert et al.

A High Efficiency 5 kW Inductive Charger for EVs Using Dual Side Control

This paper presents the design of a 5 kW inductive charging system for electric vehicles (EVs). Over 90% efficiency is maintained from grid to battery across a wide range of coupling conditions at full load. Experimental measurements show that the magnetic field strength meets the stringent International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for human safety. In addition, a new dual side control scheme is proposed to optimize system level efficiency. Experimental validation showed that a 7% efficiency increase and 25% loss reduction under light load conditions is achievable. The authors believe this paper is the first to show such high measured efficiencies for a level 2 inductive charging system. Performance of this order would indicate that inductive charging systems are reasonably energy efficient when compared to the efficiency of plug-in charging systems.

A Novel Method for Obtaining a Better Quality Speech Signal for Cochlear Implants using Kalman with DRNL and SSB Technique

Cochlear implant devices are known to exist since a long time. The purpose of the present work is to develop a speech algorithm for obtaining robust speech. In this paper, the technique of cochlear implant is first introduced, followed by discussions of some of the existing techniques available for obtaining speech. The next section introduces a new technique for obtaining robust speech. The key feature of this technique lies in the use of the advantages of an integrated approach involving the use of an estimation technique such as a kalman filter with non linear filter bank strategy, using Dual Resonance Non Linear(DRNL) and Single Side Band(SSB) Encoding method. A comparative study of the proposed method with the existing method indicates that the proposed method performs well compared to the existing method.

Left anterior descending artery perforation treated with graft stenting combining dual catheter and side branch graft stenting techniques

Reported is a technique that was used to treat a distal left anterior descending (LAD) perforation in a patient undergoing percutaneous coronary intervention (PCI) for distal LAD total occlusion. The perforation was successfully treated by re-occluding the LAD with implantation of a polytetrafluoroethylene (PTFE)-covered stent in a diagonal branch extending to the LAD (side branch graft stenting technique) delivered using the dual catheter technique. This approach is proposed as an alternative bail-out technique that can be used in cases where other treatment options for coronary perforation are either unavailable or potentially not successful, especially during PCI for total occlusions, where the disadvantage of main vessel occlusion is already present.

Decreased oxidant profile and increased antioxidant capacity in naturally postmenopausal women

Recent works have shown a dual side of estrogens, and research on the relationship between oxidative stress and menopausal status remains unclear and has produced controversial results. In this work, we aimed to evaluate by sensitive methods the oxidant and antioxidant changes that develop after natural menopause. Thirty premenopausal and 28 naturally postmenopausal women volunteered for this study. Blood was collected and plasma used. 17-OH estradiol levels in plasma were estimated. Plasma levels of advanced oxidation protein products (AOPP), lipid peroxidation products (such as hydroperoxides and malondialdehyde (MDA)), and nitrites were measured, and total radical antioxidant parameter testing was performed to determine the oxidant and antioxidant profiles, respectively. Estrogen levels were significantly increased (p < 0.02) in premenopausal women (54.28 ± 9.34 pg/mL) as compared with postmenopausal women (18.10 ± 1.49 pg/mL). Postmenopausal women had lower levels of lipid hydroperoxide oxidation (p < 0.0001), lipid hydroperoxide levels evaluated by the area under the curve (AUC; 1,366,000 ± 179,400 AUC; p < 0.01), and hydroperoxides as measured by the ferrous oxidation-xylenol orange method (31.48 ± 2.7 μM; p < 0.0001). The MDA levels did not differ between pre- and postmenopausal women whether measured by thiobarbituric acid-reactive substances or high-performance liquid chromatography assays. No differences in AOPP and nitrite levels were observed between pre- and postmenopausal women. Postmenopausal women also exhibited a higher total radical antioxidant level (0.89 ± 0.08 μM Trolox; p < 0.0001). Postmenopausal women demonstrated lower levels of oxidative damage and a higher antioxidant capacity than premenopausal women.

Amphiphilic ethyl cellulose brush polymers with mono and dual side chains: Facile synthesis, self-assembly, and tunable temperature-pH responsivities

Novel amphiphilic ethyl cellulose (EC) brush polymers with mono and dual side chains of poly(2-(2-methoxyethoxy)ethyl methacrylate)-co-oligo(ethylene glycol) methacrylate) (P(MEO2MA-co-OEGMA)) and poly(2-(N,N-dimethylamino)ethyl methacrylate) (PDMAEMA) were synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The molar ratio of P(MEO2MA-co-OEGMA) and PDMAEMA was varied through changing the feed ratio of these polymers and the coupling efficiency of click chemistry is relatively high. The brush polymers can self-assemble into spherical micelles/aggregates. The micelles/aggregates show the tunable temperature-pH responsive properties. The cloud points and the pH-triggered phase transition were influenced by EC chains and the ratio of P(MEO2MA-co-OEGMA) and PDMAEMA side chains. The brush polymers have the great potential applications as biomedical or intelligent materials.

Young diagrams, Brauer algebras, and bubbling geometries

We study the 1/4 BPS geometries corresponding to the 1/4 BPS operators of the dual gauge theory side, in ${\cal N}=4$ SYM. By analyzing asymptotic structure and flux integration of the geometries, we present a mapping between droplet configurations arising from the geometries and Young diagrams of the Brauer algebra. In particular, the integer $k$ classifying the operators in the Brauer basis is mapped to the mixing between the two angular directions.

Review of AdS/CFT Integrability, Chapter IV.2: Deformations, Orbifolds and Open Boundaries

We review the role of integrability in the planar spectral problem of four-dimensional superconformal gauge theories besides N=4 SYM. The cases considered include the Leigh-Strassler marginal deformations of N=4 SYM, quiver theories which arise as orbifolds of AdS5xS5 on the dual gravity side, as well as various theories involving open spin chains.

M5-brane defect and quantum Hall effect inAdS4×N(1,1)/N=3superconformal field theory

We study the $d=11$ gravity dual ${\mathrm{AdS}}_{4}\ifmmode\times\else\texttimes\fi{}N(1,1)$ of the $d=3$ $\mathcal{N}=3$ flavored Chern-Simons-matter theory. In the dual gravity side, we analyze the M5-brane filling ${\mathrm{AdS}}_{3}$ inside ${\mathrm{AdS}}_{4}$ and derive the quantized Hall conductivity of the dual gauge theory. In the gauge theory side, this M5-brane intersects the gauge theory at the codimension-one defect.

Natural Dualities in Partnership

Traditionally in natural duality theory the algebras carry no topology and the objects on the dual side are structured Boolean spaces. Given a duality, one may ask when the topology can be swapped to the other side to yield a partner duality (or, better, a dual equivalence) between a category of topological algebras and a category of structures. A prototype for this procedure is provided by the passage from Priestley duality for bounded distributive lattices to Banaschewski duality for ordered sets. Moreover, the partnership between these two dualities yields as a spin-off a factorisation of the functor sending a bounded distributive lattice to its natural extension, alias, in this case, the canonical extension or profinite completion. The main theorem of this paper validates topology swapping as a uniform way to create new dual adjunctions and dual equivalences: we prove that, for every finite algebra of finite type, each dualising alter ego gives rise to a partner duality. We illustrate the theorem via a variety of natural dualities, some classic and some less familiar. For lattice-based algebras this leads immediately, as in the Priestley–Banaschewski example, to a concrete description of canonical extensions.