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Trigeminal neuralgia (TN) is a debilitating condition characterized by sudden, excruciating facial pain due to neurovascular compression of the trigeminal nerve. Stent deployment can change the course of the superior cerebellar artery upwards, possibly releasing the root entry zone of the trigeminal nerve. We developed a novel stent, the Transform stent, for TN treatment, and evaluated its mechanical properties using benchtop and in vitro hemocompatibility tests. We compared the performance of Transform and Enterprise stents in treating TN because they share similar self-expanding closed-cell features in the manufacturing process, are derived from nitinol tubes, and are fabricated through a laser-cutting process, but also because only the safety of Enterprise stents deployed in intracranial arteries has been reported clinically. All benchtop measurements, including radial force, trackability, bending stiffness, and conformability, were performed thrice for each stent model, and their average values are presented. Transform stents showed higher radial forces in vessels of diameters ranging from 1.0 mm than Enterprise stents. The trackability of the Transform stent was better than that of the Enterprise stent in a neurovascular model. Bending stiffness was stronger in the Transform stent whereas conformability was superior in the Enterprise stent. No significant thrombogenic issues were observed in the in vitro hemocompatibility tests. This study demonstrated the Transform stent as a potential option and paved the way for innovative endovascular approaches for the future TN treatment. Namely, the study confirmed that the characteristics of Transform stents at benchtop and in vitro evaluations may be used as a first step for studies such as in vivo pre- and clinical studies. [ABSTRACT FROM AUTHOR]

Highlights • Aminolyzed PLLA microcylinders were introduced to a GelMA-based bioink for a better printing experience. • The printed microcylinder-laden bioink proved to have higher resolution than pure GelMA ink. • The pre-osteoblasts printed with the novel bioink exhibited increased viability compared to the conventional bioink. Abstract Developing bioinks for 3D bioprinting that are easy to print and highly biocompatible is essential for the growth of the tissue engineering field. Here, a gelatin methacryloyl-based (GelMA) bioink that is loaded with aminolyzed poly(L-lactic acid) (PLLA) microcylinders is developed. The bioink showed better printing capabilities compared to pure GelMA, which exhibited a smaller window of high quality printability. The addition of microcylinders makes the bioink more forgiving to print by increasing its minimum viscosity while keeping its structural integrity after printing. Cell viability of printed constructs was compared to non-printed constructs to see the effects of shear stress in the new bioink. [ABSTRACT FROM AUTHOR]

A bimodal grain structure consisting of fine grains ( d ~ 1–2 µm) and coarse grains ( d ~ 10–20 µm) was achieved in the biomedical Co–20Cr–15W–10Ni alloy via medium cold rolling (area reduction of 50%) followed by short-term annealing (15 min) at relatively low temperatures (950–1100 °C). The medium cold rolling induced a heterogeneous microstructure featuring the coexistence of severely deformed regions and weakly deformed domains. With short-term annealing at low temperatures, fine and coarse grains were preferentially recrystallized in severely deformed regions and weakly deformed domains, respectively, resulting a bimodal grain size distribution. During tension, dislocations were more rapidly generated in the fine grains, thus increasing the strain hardening, while they glided longer on the {111} planes in the coarse grains, contributing a high ductility. The combination of these two factors provided well-balanced strength–ductility behavior with an ultimate tensile strength of 1278 MPa, a yield strength of 787 MPa, and an elongation to fracture of 53%, making the alloy suitable for surgical implant and stent applications where the strength and ductility are both important to ensure mechanical reliability in a human body. [ABSTRACT FROM AUTHOR]

The study aims to evaluate the method of Thermal Response Tests (TRTs) in assessing in-situ residual saturation of CO 2 storage in saline aquifers. Similar to TRTs, mathematically the same type of an exact analytical solution presented by Theis is well-established for the transient drawdown in an infinite uniform confined aquifer. With the change of supercritical CO 2 and saline water in pore space, the inverse models of temperature change over time either heating or cooling may lead to the detection of a change in thermal properties of fluids and sold matrix. In assessing the overall thermal conductivity using the three inverse models, the Wang model describes the saline aquifer of the interest structurally well among the chosen four conductivity models. The results of the Wang model and the arithmetic model showed almost insensitivity to the residual CO 2 saturation up to 50 percents in the estimation of the overall thermal conductivity, while they did a sensitivity to porosity variation of the same range. Accuracy analysis of the three inversion models showed that a developed nonlinear least square inverse model produces the least error in the estimation consistently with the wide range of the residual saturation variation of CO 2 . [ABSTRACT FROM AUTHOR]

Herein, nitrogen-doped tin oxide intercalated activated carbon nanocomposite (N-AC/SnO 2 ) were prepared using hydrothermal strategy and explored as an electrode for capacitive desalination and disinfection. Although tin oxide (SnO 2 ) has good characteristics, the nitrogen must be carefully considered for modifying the characteristics of the carbonaceous materials to improve the performance as an electrode in the CDI process. The characterization of the proposed materials which investigated by XRD, TEM, FE-SEM, XPS and FT-IR affirmed the formation of the nanocomposite. The electrosorption behavior investigated by electrochemical techniques demonstrates that, compared to the specific capacitance of the AC and AC/SnO 2 (207.46 F g −1 and 233.21 F g −1 ), that of the N-AC/SnO 2 is higher at 408.8 F g −1 , and N-AC/SnO 2 exhibits better electrical conductivity. The CDI performance evaluated by batch mode experiments through an applied voltage of 1.2 V in a 50 mg L −1 NaCl aqueous solution shows that the N-AC/SnO 2 electrode introduces a higher electrosorptive capacity of 3.42 mg g −1 , an enhanced desalination efficiency of 61.13%, and good antibacterial performance. Overall, the present study demonstrates that N-AC/SnO 2 has considerable potential as an electrode material for CDI application. [ABSTRACT FROM AUTHOR]

The tensile test criterion to obtain a reliable stress-strain curve from load-displacement data of metallic materials exhibiting twinning or phase transformation was developed especially for environments that do not allow the use of an extensometer. The study shows that neither ASTM E8 / E8M standard specimen nor strip-shaped specimen geometry was appropriate for converting load-displacement data to an actual stress-strain curve; the former exhibited an undesired two-stage yield, while the latter revealed premature fracture. To solve these problems, the relationship between the specimen geometries and load-displacement data was carefully analyzed for dog-bone type specimens having a minimized fillet radius; it was found that the ratio of grip width W gr to gauge width W ga should be higher than the ratio of fracture stress to the first yield stress σ 1 . Otherwise, a second yield always occurred when the stress reached a value close to σ 1 W gr / W ga , obstructing the data analysis to reconstruct the actual stress-strain curve from load-displacement data. Finally, a methodology to verify whether the tensile test satisfied the criterion was suggested in terms of a nominal strain hardening rate. [ABSTRACT FROM AUTHOR]

The effect of the solution treatment and aging (STA) conditions on the tensile properties of Ti–4 mass%Fe–4 mass%Al–0.25 mass%Si alloy has been investigated in this work. The obtained results revealed that varying the solution temperature affected the stability of the β phase due to the Fe partitioning (which inhibited the β→α′/α″ reaction during water quenching), while the magnitude of the aging temperature determined the predominant products of the β→isothermal ω→secondary α rich →secondary α lean +TiFe phase transformation with distinct tensile characteristics. In addition, the relationship between the alloy microstructure and its tensile properties was discussed. [ABSTRACT FROM AUTHOR]

Microstructure, mechanical properties as well as phase transformation behavior of newly developed Ni 49 Ti 36 Hf 15-x Ta (x=0, 3, 6, 9, 12) high temperature shape memory alloys has been investigated. Ni 49 Ti 36 Hf 15 alloy consists of (Ti,Hf) 2 Ni phase which is brittle and incoherent with the martensite matrix. However, addition of Ta in place of Hf suppresses the brittle (Ti,Hf) 2 Ni phase formation with white Ta rich phase. More than 70% reduction in area has been observed in Ta added Ni 49 Ti 36 Hf 15 high temperature shape memory alloys. The austenitic transformation temperature is well above 200 °C (473 K) for lower Ta concentrations with up to 6 at. %; however; at higher Ta concentrations (i.e. above 9 at. %) decreases significantly. Overall, the addition of Ta greatly influences the hot deformation behavior and high temperature shape memory properties of Ni 49 Ti 36 Hf 15 alloy. The present paper discusses the detailed investigation on Ni 49 Ti 36 Hf 15-x Ta (x=0, 3, 6, 9, 12) high temperature shape memory alloys. [ABSTRACT FROM AUTHOR]

The mechanisms of dynamic recrystallization (DRX) in a 50Ti-47Ni-3Fe alloy are studied using compression tests at temperatures of 1023–1323 K with strain rates of 0.01–10 s −1 , and the resulting stress-strain curves are used to construct an Arrhenius equation with a Zener-Hollomon parameter (Z). The relationship between this Z parameter and stress, and its effect on the subgrain size are discussed. With the help of electron backscatter diffraction (EBSD), the development of recrystallizing grain boundaries is tracked in deformed grains with different grain orientation spread (GOS) values. Continuous dynamic recrystallization (CDRX) is subsequently confirmed by evidence of the conversion of low-angle boundaries (LAGBs) into high-angle boundaries (HAGBs). Grain boundary sliding (GBS) and HAGB migration are therefore considered secondary mechanisms under high-Z (ln Z > 29) and low-Z (ln Z < 23.5) conditions, but CDRX is confirmed as the dominant DRX mechanism. [ABSTRACT FROM AUTHOR]

This study develops and characterizes a fiber-optic monitoring system for the key environment variables of the spent nuclear fuel pool (SNFP) at a nuclear power plant. The three key environmental variables indicating the SNFP status directly are its water temperature, water level, and radiation level. First, this study develops and characterizes the individual fiber-optic sensors for measuring the three key environmental variables and then assembles them into an integrated monitoring system. The individual fiber-optic sensors commonly use optical fibers to transmit the signals delivered from their sensing probes despite their different characteristics. For the fiber-optic temperature sensor (FOTS), two types of FOTS are developed: contact and non-contact types, which are distinguished by whether their sensing probes are in direct contact with water. The contact-type FOTS uses a copper metal cap as its sensing probe, and the non-contact-type FOTS uses an infrared optical fiber, whose peripheral surface is coated with an anti-fog solution as its sensing probe. The fiber-optic water level sensor (FOWS) consists of optical fibers with their ends connected to the sensing probes fabricated with a NaCl solution and stainless steel. The FOWS measures the water level using the Fresnel reflection phenomenon, i.e., reflection of a portion of incident light at a discrete interface between two media having different refractive indices. The FOWS identifies the water level by measuring the amount of light reflected at the interface between the sensing probe and its outside medium, which varies according to whether the sensing probe is in contact with water. The fiber-optic radiation sensor (FORS) measures the gamma radiation in the SNFP. The sensing probe of FORS is a cylindrical-shaped LYSO:Ce scintillator, whose peripheral is wrapped with aluminum foil as the reflector. After characterizing the three individual sensors developed in this study, they are assembled and tested at a model water pool, 500 mm × 500 mm × 500 mm in size. The performance test results shows that individual sensors can measure the changes in each environmental variable in real-time. [ABSTRACT FROM AUTHOR]

• Instantaneous current residual map (ICRM) is proposed for CNN-based fault diagnosis. • ICRM highlights fault-related physical behaviors of stator motor current signals. • A motor fault type can be figured out by using ICRM as the 2D input to a CNN model. • The effectiveness of ICRM for fault diagnosis of a PMSM is experimentally validated. To take full advantage of a convolutional neural network (CNN) for deep learning-based fault diagnosis, many studies have examined the transformation of sensory signals into a two-dimensional (2D) input image. An important question to consider is: how can fault-related signatures in motor stator current signals be incorporated into the 2D input image to a CNN model for fault diagnosis of a permanent magnet synchronous motor (PMSM)? To answer the question, this study newly proposes a novel health image, namely instantaneous current residual map (ICRM). Inspired by the idea that the phase and amplitude modulations in motor stator current signals are related to faulty states of a PMSM, the overall procedure for constructing ICRM includes two key steps: (1) to calculate current residuals (CRs); and (2) to spread the scaled CR pairs into a 2D matrix. A type of faults can be figured out by analyzing a degree or shape of spreading of the CRs in ICRM. Moreover, ICRM is robust to variable operating conditions in practical settings because the scaled CRs that the effects of the operating conditions are reduced can highlight fault-induced irregularities. To demonstrate the effectiveness of ICRM, it was experimentally validated using a surface mounted PMSM, operated under variable-speed and different load torque conditions. [ABSTRACT FROM AUTHOR]

A tissue engineering composite scaffold serves as a temporary skeleton to accommodate and stimulate new tissue growth. Here we report the development of a biodegradable porous composite scaffold made from the bioactive chitosan (CHN) and hyaluronic acid (HYA) with graphene oxide (GO). The CHN–HYA–GO composite scaffold was successfully prepared and compared with CHN-HYA composite scaffold and found that CHN–HYA–GO significantly improved mechanical and biological properties. Moreover, the CHN–HYA–GO composite scaffold possessed an adequate porosity, swelling behavior and degradation rate to mimic the extracellular matrix (ECM) with a favorable cell attachment and proliferation. The cells in contact with CHN–HYA–GO composite scaffolds remained viable and exhibited a high growth potential. Therefore the uniquely fabricated CHN–HYA–GO composite scaffolds possess great potential for various tissue engineering applications. [ABSTRACT FROM AUTHOR]

Bulk nanocrystalline ( d = 20–40 nm) Ni–Ti shape memory alloy was produced via cold marforming, followed by optimum post-heat treatment. The total accumulative strain ( ε ∼ 0.7) during the process was much lower than that typically imposed during severe plastic deformation operations (i.e., 5 ≤ ε ≤ 12). In-situ heating transmission electron microscopy revealed that the present process was effective in promoting static recrystallization and limiting grain growth. The nanocrystalline alloy exhibited enhanced shape memory behaviors. [ABSTRACT FROM AUTHOR]

Plastic anisotropy and associated deformation mechanisms of rolling textured high purity alpha phase titanium were investigated by carrying out uniaxial compression tests along the three featured directions, the rolling direction (RD), normal direction (ND) and transverse direction (TD), in combination with an electron backscatter diffraction measurement and a Schmid factor (SF) analysis. The results revealed that the specific crystallographic feature of the material, caused by rolling texture, influences the activities of dislocation slips and twinning by affecting their SF, and this significantly varies with the loading direction, consequently leading to anisotropic deformation. The material yielding was dominated by dislocation slips, and the change of yielding mechanism with the loading direction (prismatic slip for the RD and TD, and basal slip for the ND) gave rise to yielding anisotropy. As the material deformed beyond the yielding point, deformation twins took place and played a decisive role in the deformation. The twinning characteristics including types of twins, morphology, twin area fraction with strain and related texture modification significantly varied with the loading direction, and this had a completely different effect on strain hardening behavior, thereby causing deformation anisotropy. [ABSTRACT FROM AUTHOR]

We developed a geothermal monitoring system with an open-source Internet of Things (IoT) system. The study's objective is to achieve an economical alternative solution to the expensive commercial data loggers, local PC-based control, data storage limitation, the number of sensor connections, and secure data transmission over the Internet in a decentralized renewable energy system. The developed system consists of hardware and software customized with open-source support that helps resolve the conventional limitations that the commercial system inherently has. We have applied the system to a geothermal energy system deployed at a residential care facility for the elderly in Chuncheon, South Korea. The proposed system enabled us to acquire the data of temperature and fluid flow in real-time and for a prolonged period (i.e., years) at an affordable price compared to installing a conventional data-acquisition system. The real-time multi-year-long data helped confirm seasonality in heating and cooling. We can also apply the same proposed system to the other renewable energy systems monitoring temperature, pressure, wind speed, displacement, noise, seismicity, etc. • Development of a geothermal monitoring system with an open-source IoT system. • The system was applied to a geothermal system deployed at a residential care facility. • The real-time multi-year-long data helped confirm seasonality in heating and cooling. • We can also apply the same proposed system to the other renewable energy. [ABSTRACT FROM AUTHOR]

Functional graded nanobiomembranes (FGMs) with multiple layers were created by a single process using a novel electrospinning system equipped with a generator and a PCI type motion board as a controller in order to control the drug release rate. By varying physical apparatus-related parameters such as nozzle-to-collector distance via a robot and the collector moving velocity the FGMs were formed. For the membrane base layer, poly-(ε-caprolactone) (PCL) with paclitaxel (PTX) was dissolved in a solvent (dichloromethane, N,N-dimethylformamide) and electrospun. For the top layers, the PCL solution was electrospun according to the distance and FGM system parameters, which can move the collector location at a constant ratio. It was observed that pore size, porosity, and permeability were higher when the membrane was spun at the far distance. The top surface of FGM is more porous, rougher, more permeable, and more hydrophilic so as to be active to the surrounding tissue cells. Meanwhile, the porous inside membrane was as low as the membrane spun at a close distance. Thus it induced a slow drug release due to the internal structure of FGM, which is considered to be very effective for slow drug release as well as bioactivity and bioconductivity. [ABSTRACT FROM AUTHOR]

Feature selection based on an ensemble classifier has been recognized as a crucial technique for modeling high-dimensional data. Feature selection based on the random forests model, which is constructed by aggregating multiple decision tree classifiers, has been widely used. However, a lack of stability and balance in decision trees decreases the robustness of random forests. This limitation motivated us to propose a feature selection method based on newly designed nearest-neighbor ensemble classifiers. The proposed method finds significant features by using an iterative procedure. We performed experiments with 20 datasets of microarray gene expressions to examine the property of the proposed method and compared it with random forests. The results demonstrated the effectiveness and robustness of the proposed method, especially when the number of features exceeds the number of observations. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effects of particle size and other injection factors on the skin penetration of nanoparticles delivered with a needle-free injector. Experimental and simulation tests were carried out at various parameters. In addition to testing different sizes of nanoparticles, we also observed the effects of several injection pressures and syringe orifice diameters (SOD) on the dispersion pattern of the nanoparticles after injection. Our results showed that as the nanoparticle size increased from 45 nm to 452 nm, the resulting puncture opening, channel diameter, and depth of the nanoparticle dispersion decreased, but the width of the dispersion increased. Conversely, as the SOD increased, the puncture opening, channel diameter, and depth of the dispersion increased, but width of the dispersion decreased. Increasing the injection pressure also decreased the size, depth, and width of the puncture opening. These results identify how these three parameters affect nanoparticle delivery from a needle-free injector; therefore, our findings will be beneficial for optimization and further study of needle-free injectors as a mechanism for transdermal delivery of nanoparticles. [ABSTRACT FROM AUTHOR]

Highlights: [•] We have investigated the effect of cold working on the martensitic transformation. [•] The TiNi wire showed multiple-stage martensitic transformation behavior. [•] The multiple-stage transformations originated from microstructural instability. [ABSTRACT FROM AUTHOR]

Abstract: Beta-TCP (β-TCP) particle-containing LA/PCL micro/nanofibers were fabricated via a one-step electrospinning process. The morphology and chemical structure of the composite nanofibers were characterized by FESEM, XRD, and FTIR. Rougher surfaces were observed for the LA/PCL micro/nanofibers containing β-TCP compared to the neat LA/PCL fibers, which could possibly provide extra sites for cell binding. XRD and FTIR confirmed the presence of β-TCP as being firmly deposited on the fibers. After an immersion in distilled water, we observed that the β-TCP-containing composite fibers were more degradable with many damaged and broken fibers compared to the LA/PCL fibers. MTT assay and immersion test showed better cell viability and proliferation, and improved mineralization ability compared to the LA/PCL only mat. Thus, the incorporation of β-TCP and the presence of LA in PCL micro/nanofibers could result to an improved biocompatibility and faster degradation of the composite fibers, which would possibly be useful for tissue scaffold application. [Copyright &y& Elsevier]

Highlights: [•] Low temperature milling effectively decreased grain size. [•] Low temperature milling was very effective in oxide particle size reduction. [•] Homogeneous distribution of Y2O3 was very important for fine microstructure. [•] Tensile strength was significantly increased by low temperature milling. [Copyright &y& Elsevier]

Highlights: [•] Flow softening of Ti–6Al–4V with a lamellar microstructure was modeled. [•] Flow softening originated from colony rotation and alpha particle coarsening. [•] The model provided an accurate prediction of the flow response during hot working. [ABSTRACT FROM AUTHOR]

Abstract: This study reports on the effect of high-frequency magnetic field on the heating of electrospun polyurethane (PU) nanofibers decorated with Fe2O3 nanoparticles (NPs). The morphological and thermal properties were checked by several characterization techniques. Here, the effect of Fe2O3 NP concentration and intensity of magnetic field on the inductive heating of the composite mat were investigated. Fe2O3 nanoparticles were confirmed to be embedded on/in the nanofibers and their presence has increased the thermal stability of the composite nanofibers compared to the neat PU nanofibers. The composite nanofibers under high-frequency magnetic field showed a temperature increase of 3–17% with respect to the neat PU nanofibers depending on the Fe2O3 NP concentration and magnetic field strength. The present results suggest the potential use of electrospun nanofibers as good substrate for magnetic nanoparticles, and when exposed to external magnetic field, can induce heating that may be useful for localized hyperthermia application. [Copyright &y& Elsevier]

Abstract: The aim of this study was to survey the radon concentrations at 21 elementary schools in Gyeongju, Republic of Korea, to identify those schools with high radon concentrations. Considering their geological characteristics and the preliminary survey results, three schools were finally placed under close scrutiny. For these three schools, continuous measurements over 48h were taken at the principal's and administration office. The radon concentrations at one school, Naenam, exceeded the action level (148Bq/m3) established by the U.S. EPA, while those at the other two schools were below that level. [Copyright &y& Elsevier]

The formation of submicrocrystalline (SMC) Ti–6Al–4V was achieved by imposing a much lower strain (ε =1.4) compared to that typically imposed during severe plastic deformation operations (i.e. 4⩽ ε ⩽8). Electron backscatter diffraction analysis revealed that the novel process was effective in promoting dynamic recrystallization and limiting α grain growth. The SMC sheet had much higher yield strength than usual (1134MPa) and reasonable elongation (∼12%) at room temperature, and exhibited enhanced ductility at elevated temperatures. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a simple and efficient strategy was developed for preparing flower-shaped ZnO doped reduced graphene oxide (RGO) composite material by simultaneous crystal growth (of ZnO) and reduction (of graphene oxide) using hydrothermal process. Several analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy have been used to characterize the resulting ZnO/RGO photocatalyst. Results showed that highly crystalline ZnO nano-flowers were effectively doped on the surface of RGO sheets. The unique properties of RGO sheets not only provide the decreased rate of electron–hole separation in ZnO but also prevent from the loss of photocatalyst during recovery due to the fixed attachment of ZnO NPs on the surface of high aspect ratio graphene sheets. Therefore, as-synthesized composite is an economically and environmentally friendly photocatalyst. [Copyright &y& Elsevier]

Abstract: Multiwalled carbon nanotube/polyurethane (MWNT/PU) composites were prepared by electrospinning and solution casting. The morphological and thermal properties, and mechanical performance of the nanofiber and film composites were characterized and compared. The tensile strength of neat PU film was 9-fold higher than that of neat PU nanofibrous mat. The incorporation of MWNTs increased the tensile strength and modulus of the composite nanofibers by 69% and 140%, respectively, and 62% and 78%, respectively for composite films. The MWNT/PU composites showed an improved thermal degradation behavior, with the incorporation of low MWNT content in the composites. [Copyright &y& Elsevier]

Abstract: In this study, we describe the enhancing ability of electrospun polyurethane (PU) nanofibers containing carbon nanotubes (CNTs) as nanofillers for silicone film in improving the physico-mechanical properties of the composite material. We prepared the samples combining two simple techniques: solution casting and electrospinning. Neat PU nanofibers alone are good reinforcing materials but the presence of CNTs inside the PU nanofibers has drastically improved the mechanical properties of the silicone composite film. The silicone film increased its tensile strength by 226% and its tensile modulus by more than 14-fold when CNT/PU nanofibers were incorporated. [Copyright &y& Elsevier]

Abstract: Here, we report a simple heat-treatment process to prepare hydroxyapatite (HA)-coated Ti6Al4V anterior cruciate ligament (ACL) anchor that has good hard tissue compatibility and biostability. Heat treatment was carried out for 1.5h at temperature range of 700–900°C. Morphological characterization showed rougher surface and larger pore spaces as the heat treatment temperature was increased. The Ti6Al4V heat-treated at 800°C had the highest diffused titanium phosphide formation, thus making it high in biocompatibility. For in vivo test, the most bone integration ability was obtained for heat-treatment at 800 and 900°C. Furthermore, the HA/Ti6Al4V ACL anchor heat-treated at 800°C had the highest amount of new bone formation. The present results suggest that an implant with complex shape like an ACL anchor could be prepared and used with an easy and low-cost technique by simple heat treatment surface modification method after dip-coating with HA. [Copyright &y& Elsevier]

Abstract: In this work, nylon-6 spider-wave-like nano-nets are fabricated by regulating the amount of graphene oxide (GO) in polymer solution during electrospinning. The spider-wave-like nano-nets that comprise interlinked thin (≈14nm diameter) and thick fibers (≈192nm diameter) are widely distributed throughout the mat when suitable amount of GO is blended with nylon-6 solution. The heterogeneous composite mats were composed of bimodal nanofibers in which pore diameter was sufficiently decreased. The acceleration in ionization and degradation of nylon-6 (due to formic acid) solution caused by well-dispersed GO sheet as well as the formation of hydrogen bond between nylon-6 molecules and GO sheet during electrospinning are proposed as the possible mechanisms for the formation of these spider-wave-like nano-nets. [Copyright &y& Elsevier]

Abstract: In this study, TiO2-impregnated ZnO nano-flowers were synthesized by one-pot hydrothermal process. Aqueous suspension containing ZnO precursor and commercial TiO2 NPs (P25) is heated at 140°C for 2h. The morphology and structure of as-synthesized particles were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), which revealed that TiO2 NPs were attached on the surface of ZnO flower. It was observed that the presence of TiO2 NPs in the hydrothermal solution could sufficiently decrease the size of ZnO flower. The hybrid nanostructure, with unique morphology, obtained from this convenient method (low temperature, less time, and less number of reagents) was found to be effective photocatalyst under UV-irradiation. [Copyright &y& Elsevier]

Abstract: Uniaxial tensile properties influenced by the dynamic recrystallization (DRX) behavior of the partially strain-hardened magnesium AZ31 sheets (H24) containing scores of twins were investigated and compared to those of fully annealed ones (O) with absence of twins. For this purpose, a series of uniaxial tensile tests were carried out for the H24 and O materials at temperatures ranged from room temperature to 300°C and at strain rates between 10−3 and 10−1 s−1. At 150 and 200°C, the H24 material exhibited higher yield strength without much loss in elongation compared to those of the O material; this trend was attributed to the continuous DRX along or around grain boundaries as well as extensive twin-aided DRX inside grains. In addition, the post-deformation hardness value of the H24 material showed higher than that of the O material. On the other hand, at higher temperatures of 250 and 300°C, it was observed that twins shown in the H24 material were disappeared even prior to deformation, resulting in the similar grain structure and mechanical property values to those of the O material, e.g., discontinuous DRX associated with grain boundary bulging. Finally, the initiation of DRX was rationalized in terms of microstructure morphology, deformation temperature and strain rate, and then modeled in the context of strain hardening rate analysis. A comparison of experimental results and predictions for both H24 and O materials showed that the model can provide a reasonable prediction of critical strain to initiate DRX. [Copyright &y& Elsevier]

Abstract: The aim of the present study is to evaluate the influence of nano-sized carbides upon tensile behavior in UFG medium-carbon steels and to develop a material with improved tensile properties. UFG medium-carbon steels with fine carbides were successfully fabricated by multi-pass caliber rolling at 773K. Alloying chromium and molybdenum resulted in thinner pearlitic lamellae, which were transformed into finer particles after severe plastic deformation. The UFG steel containing the alloying elements exhibited superior tensile properties, which was attributed to the enhanced strain hardening rate by the imbedded finer particles. Subsequent annealing induced growth of grains and particles, which also recovered elongation at the expense of strength. All UFG steels investigated here showed a yield-point phenomenon due to the decreased hardening rate and lack of mobile dislocations and their sources. The deteriorating effect of particle growth overwhelmed the improving effect of grain growth after annealing of the UFG medium-carbon steel, leading to a reduced strain hardening rate. This resulted in a positive correlation between a grain size and Lüders elongation in the investigated UFG steels. [Copyright &y& Elsevier]

Abstract: Measuring the level of radioactive contamination in a high-radiation area with a complex geometry requires a new measuring system that can be operated remotely and free of electronic noise by radiation. In this study, a measuring system suitable for measuring high-level radioactive contamination in the narrow gap of a nuclear facility was developed. The measuring system was a fiber-optic remote system using an organic scintillator, epoxy resin and an optical fiber. The measuring system was tested for Cs-137 and Sr/Y-90 radiation sources, and could measure radioactive contamination remotely in a narrow area. [Copyright &y& Elsevier]

Abstract: This study aims to develop a unified constitutive model describing the flow behaviors of pure Ta and Ta–W alloys over a wide range of strain rate and temperature. The model was based on the previously suggested model by Nemat-Nasser and Isaacs and was further extended to capture the hardening effects caused by the changes in solute contents and concentrations, and grain size; while interstitial solutes (C, N, and O) increased the thermal stress, substitutional solute (W) increased both the thermal and athermal stresses. The results showed that the developed model can provide a reasonable prediction on the flow behaviors of pure Ta and Ta–W alloys (Ta–2.47W, Ta–5.2W, and Ta–9.8W) with different grain sizes of 0.3–45μm over a strain rate range of 1–10−6 s−1 and a temperature range of 77–900K without any change in the material constants used. [Copyright &y& Elsevier]

Abstract: The low-temperature superplasticity and dynamic coarsening behavior of Ti–6Al–2Sn–4Zr–2Mo–0.1Si were established and interpreted in the context of inelastic-deformation theory. The starting microstructure with an equiaxed-alpha particle size of 13μm was refined to 2.2μm by a treatment comprising beta annealing/water quenching followed by warm rolling at 775°C. A series of tension and load-relaxation tests were carried out for the coarse and fine microstructures at strain rates of 10−4 to 10−2 s−1 in the temperature range of 650–750°C. The fine microstructure exhibited enhanced superplasticity (382–826% elongation) compared to that of the coarse microstructure (189–286% elongation); this trend was attributed to a larger fraction of boundary sliding and lower friction stress for the finer material. With respect to microstructure evolution, the coarsening rate of the alpha particles during deformation was ∼12 times faster than that during static coarsening. Furthermore, both the static and dynamic coarsening rates for the Ti–6Al–2Sn–4Zr–2Mo–0.1Si were 2.7–4.7 times lower than those for the Ti–6Al–4V, a trend attributable to the lower diffusivity of Mo compared to that of V at a given test temperature. The plastic flow behavior of the coarse and fine microstructures was rationalized in terms of microstructure evolution during deformation. [Copyright &y& Elsevier]

Abstract: This study aimed to achieve enhanced mechanical compatibility of Ti–13Nb–13Zr alloy by producing submicrocrystalline microstructure without imposing severe strains. In order to find the optimum processing conditions, a series of compression tests was performed for initial martensite microstructure in strain ranges up to 0.8 and 1.4, the strain rate range of 10−3 to 1s−1 and the temperature range of 500–700°C. Based on the microstructural analysis, the submicrocrystalline (∼0.4μm) alloy consisting of high-angle grain boundaries was produced via dynamic globularization at temperature of 600°C, equivalent strain rate of 10−1 s−1 and strain of 1.4, which showed about 25% enhanced mechanical compatibility as compared to the conventionally produced ones. The formation of submicrocrystalline microstructure at relatively low strain was investigated by examining the microstructure before and after dynamic globularization. [Copyright &y& Elsevier]

Abstract: This study aimed to determine the optimum processing conditions for dynamic globularization of Ti–6Al–4V alloy having martensite microstructure, and to achieve enhanced superplasticity. A series of isothermal compression tests was carried out for martensite microstructure in the strain range of 0.6–1.4, the strain rate range of 10−3 s−1 to 1s−1 and the temperature range of 973–1223K. At each test condition, a quantitative analysis was made to measure the fraction of dynamic globularization associated with fragmentation of initial lamellar structures. It was found that the dynamic globularized fraction increased with increasing strain and with decreasing strain rate and/or temperature tested. Based on the processing map and microstructural analysis, the optimum processing condition to obtain the finest equiaxed microstructure was determined. A very high elongation over ≈1000pct was achieved at relatively high strain rate superplasticity regime (>10−2 s−1). The present enhanced superplasticity was rationalized by examining the microstructures of the alloy associated with dynamic globularization. [Copyright &y& Elsevier]

Abstract: The quinolone analog SQ-4004 has been identified as a potentially excellent anti-ischemic agent, which exhibited highly potent efficacy in reducing infarct volume size in vivo rat MCAO model (32.1% at 0.01mg/kg) and potent cardioprotective effect at myocardial infarction in vivo model (26.6% at 0.01mg/kg) while it exhibited highly reduced anti-bacterial activity. The mechanistic study revealed that the anti-ischemic activity might exert via an anti-apoptotic pathway, which implies its therapeutic uses against the ischemic cell injuries including ischemic stroke and ischemic heart disease. [Copyright &y& Elsevier]

In this paper the Elder problem is studied with the purpose of evaluating the inherent instabilities associated with the numerical solution of this problem. Our focus is first on the question of the existence of a unique numerical solution for this problem, and second on the grid density and fluid density requirements necessary for a unique numerical solution. In particular we have investigated the instability issues associated with the numerical solution of the Elder problem from the following perspectives: (i) physical instability issues associated with density differences; (ii) sensitivity of the numerical solution to idealization irregularities; and, (iii) the importance of a precise velocity field calculation and the association of this process with the grid density levels that is necessary to solve the Elder problem accurately. In the study discussed here we have used a finite element Galerkin model we have developed for solving density-dependent flow and transport problems, which will be identified as TechFlow. The results of our study also indicate that the density differences are critical in the solution of the Elder problem and that high density differences lead to the physical instability that is inherent with this problem. Other than the physical instability associated with the level of density differences used in the Elder problem, the following two points should be considered in solving the Elder problem in a consistent manner: (i) strict attention should be paid to the vertical grid Peclet number in developing the criteria for convergent grid selection; and, (ii) with a globally continuous velocity calculation stable solutions can be obtained at lower grid densities. [Copyright &y& Elsevier]

Abstract: Carbon black powder is modified by applying a coating of a proton-conducting polymer electrolyte (ionomer), namely, perfluorosulfonic acid. The carbon is intended for use as a catalyst support in the preparation of Pt-Ru catalysts for direct methanol fuel cell. The aim is to extend the interfacial area between the catalytic metal particles and the proton-conducting ionomer. Ionomer incorporation is found to reduce the micropore volume and thus the BET surface-area of the carbon. Single-cell performance tests on a DMFC show that Pt-Ru catalyst supported on modified carbon exhibits superior performance to that on plain carbon. [Copyright &y& Elsevier]

Abstract: A series of Co–ferrierite catalysts (Co–FERs) containing a variety of Co contents in the range 0.06

The synthesis of ideal bioceramics to guide the fate of cells and subsequent bone regeneration within the chemical, biological, and physical microenvironment is a challenging long-term task. This study developed amorphous calcium magnesium phosphate (ACMP) bioceramics via a simple co-precipitation method. The role of Mg2+ in the formation of ACMP is investigated using physicochemical and biological characterization at different Ca/Mg molar ratio of the initial reaction solution. Additionally, ACMP bioceramics show superior cytocompatibility and improved osteogenic differentiation of co-cultured MC3T3-E1 cells. Regulation of the microenvironment with Mg2+ can promote early-stage bone regeneration. For this, bioprinting technology is employed to prepare ACMP-modified 3D porous structures. Our hypothesis is that the incorporation of ACMP into methacrylated gelatin (GelMA) bioink can trigger the osteogenic differentiation of encapsulated preosteoblast and stimulate bone regeneration. The cell-laden ACMP composite structures display stable printability and superior cell viability and cell proliferation. Also, constructs loading the appropriate amount of ACMP bioceramic showed significant osteogenic differentiation activity compared to the pure GelMA. We demonstrate that the dissolved Mg2+ cation microenvironment in ACMP-modified composite constructs plays an effective biochemical role, and can regulate cell fate. Our results predict that GelMA/ACMP bioink has significant potential in patient-specific bone tissue regeneration. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, titanium dioxide nanoparticles were synthesized employing a simple sol-gel method followed by calcination at four different temperatures (450 °C, 650 °C, 850 °C, and 1050 °C). Effect of calcination temperature on surface morphology, particle shape and size, phase transitions, optical properties, and osteogenic differentiation were then studied. Phase changes (anatase, anatase-rutile, and rutile) of TiO 2 nanoparticle were observed as the calcination temperature increased to 450 °C, 650 °C, 850 °C, and 1050 °C. The surface morphology also transformed from smooth to granular as the calcination temperature increased from 450 °C to 1050 °C. The particle size of titanium dioxide nanoparticles was found to be about ∼ 300 nm. It remained almost the same as the calcination temperature increased from 450 °C to 850 °C. Optical spectra of TiO 2 nanoparticles prepared at 450, 650, and 850 °C showed maximum absorbance in the visible-NIR region whereas TiO 2 nanoparticles prepared at 1050 °C displayed maximum absorbance in the UV region with a distorted morphology. TiO 2 nanoparticles prepared at 450 °C and 650 °C were found to have excellent biocompatibility as suggested by cell viability analysis using fibroblasts. In addition, hBM-MSCs were used to evaluate osteogenic differentiation of different structural phases of TiO 2 nanoparticles calcined at various temperatures. [ABSTRACT FROM AUTHOR]

• Bronsted and Lewis mixed base 2.5-Li@CaO-Ca(OH) 2 -450 nanocatalyst. • High surface area and high basic strength of prepared nanocatalyst. • One-step and two-step amidation of non-edible high free fatty acid containing triglycerides with 99 % yield. • The prepared catalyst showed excellent reusability and structural stability. • The amide derivative was found as a dual functional diesel fuel additive. In the present study, the 2.5-Li@CaO-Ca(OH) 2 -450 nanocatalyst (a mixture of Bronsted base Ca(OH) 2 and Lewis base CaO) of 30−50 nm size nanoparticles was prepared by a simple wet-chemical method and utilized as a heterogeneous solid catalyst for the one-step and two-step amidation of non-edible high free fatty acids containing triglycerides (TGR) such as waste cooking oil (CO), Karanja oil (KO) and jatropha oil (JO). The 2.5-Li@CaO-Ca(OH) 2 -450 nanocatalyst took 45 min, 75 min, and 120 min for the complete one-step amidation (99 % yield) of CO, KO, and JO, respectively. In two-step amidation, the prepared nanocatalyst took 30 min and 45 min in the first step to prepare fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE) from CO and then took 20 min and 30 min for complete amidation of FAME and FAEE. The first-order rate constants for the amidation of TGR, FAEE, and FAME were calculated as 0.10 min−1, 0.151 min−1, and 0.225 min−1, respectively. The 2.5-Li@CaO-Ca(OH) 2 -450 nanocatalyst was recycled and reused for ten reaction cycles for amidation and also found to complete amidation at room temperature (25−30 °C). The prepared amide derivative acted as a dual functional diesel fuel additive and found to improve the cetane number from 52.6 to 56.1 and lubricity from 460 to 247 μm of diesel fuel. [ABSTRACT FROM AUTHOR]

In this study, Ti–4%Al–2%Fe–(1–4)%Mn alloys exhibiting transformation-induced plasticity (TRIP) were investigated using electron backscattering diffraction (EBSD). Fe, Al, and Mn are all low-cost elements with low melting points, making them suitable alloying elements for next-generation α + β titanium alloys with high strength and ductility. A pronounced solution temperature and Mn content dependence of the tensile behavior was observed. The solution temperature affected the β stability i.e., the kinetics of TRIP, because the Fe and Mn atoms (strong β stabilizers) were partitioned to the retained β phase during solution treatment in the α + β region. When the Mo equivalent content was between 8.4 and 10.4, the alloys exhibited an excellent combination of strength (>1.1 GPa) and ductility (>25%). On the other hand, solution treatment in the β region bestowed the same alloys with brittleness, even though the Mo equivalence was similar. During deformation, the alloys exhibited a stress-induced martensitic transformation followed by martensite coalescence. The transformation could increase the strain hardenability, but the coalescence could not. Experiments revealed that the coalesced martensite grains were propositional in size to the prior β grains. Solution treatment in the β region resulted in β coarsening, resulting in relatively low strain hardenability. [ABSTRACT FROM AUTHOR]

In this study, a Ti–3Mo–3Cr–2Fe–2Al alloy (α + β Ti alloy) showing twinning- and transformation-induced plasticity was investigated. The existence of α yielded fine-grained β phases. The β grains, comprising low-angle boundaries, produced a high yield strength of 737 MPa despite the low α volume percentage. Martensite and twin interactions with these boundaries induced local stress concentrations. These led to a high work-hardening rate compared to that in a full β microstructure. The α + β Ti alloy showed an excellent combination of strength (1324 MPa) and ductility (0.37). Image 1 • α+β Ti–3Mo–3Cr–2Fe–2Al alloy showed the twinning- and transformation-induced plasticity. • The existence of α developed sub-grained structure and yielded the grain refinement. • Both twin and martensite impinged the low angle boundaries resulting in local stress concentration. • The sub-grained structure caused by α exhibited an excellent tensile properties. [ABSTRACT FROM AUTHOR]

Abstract In this study, the deformation mechanism of a metastable Ti-4Al-4Fe-0.25Si-0.1O alloy was investigated via ex-situ electron backscattering diffraction (EBSD) and field-emission transmission electron microscopy (FE-TEM). A stress-induced α′-martensitic transformation occurred from the retained β phase. New variants of α′-martensite were nucleated and grew in the transformed α′-martensite under increasing levels of applied stress. Microstructural observations revealed that the orthorhombic nanodomains were sheared in the prior α′-martensite; these sheared nanodomains contributed to the formation of different variants of α′-martensite. This additional martensitic transformation resulted in an excellent combination of strength (ultimate tensile strength; UTS: 1340 MPa) and ductility (30%). Highlights • Ti-4A-4Fe-0.25Si alloy showed the stress-induced α′-martensite transformation. • Randomly distributed nano-domain was sheared by the martensite transformation. • The sheared domains were transformed to secondary martensite. • This stepwise transformation exhibited an excellent tensile properties. [ABSTRACT FROM AUTHOR]

Highlights • The electrospinning was developed for fabrication of collagen mimetic scaffold. • With addition of LA, LA assisted formation of 3D cotton-like fibrous structure. • The physicochemical properties of the as-fabricated scaffold were evaluated. Abstract The ability to mimic the topography of aligned collagen fiber bundles (A-CFB) that form the structural basis for the extracellular matrix (ECM) can be an important step in the fabrication of engineered scaffolds. Because the cell adhesion to the surface topography involve cell adhesion localized structures, topographical features, which mimics the A-CFB of the matrix can be a significant factor for cell activities. In this study, we present a novel method for the fabrication of low-density electrospun fibers mimicking A-CFB constructs. The three dimensional (3D) cotton-like A-CFB mimetic scaffold (3D-CACMS) of a mixture of lactic acid (LA) and polycaprolactone (PCL) was prepared by multiple pins rotator electrospinning (MPRES), followed by selective leaching of LA. The results of SEM, FTIR, TGA, and DSC revealed the physicochemical properties of the as-fabricated scaffold. This 3D-CACMS attempt to mimic A-CFB and can potentially meet the requirements for practical use of biomedical engineering. [ABSTRACT FROM AUTHOR]

• The electrospun membrane added with βCD/GA inhibits the growth of bacteria. • The content of GA determined the antibacterial activity of the electrospun membranes. • The developed membrane is expected to be used for the development of wound treatment. Licorice contains glycyrrhizic acid, an antibacterial and anti-inflammatory component widely used as an ingredient for disinfection and trauma treatment since ancient times. In this study, antibacterial capsules were prepared by conjugating glycyrrhizic acid as a natural antibacterial substance with β-cyclodextrin. In addition, after mixing it with a polymer solution, it was successfully manufactured into fibers using an electrospinning technology. Through several analyzes, it was confirmed that the antibacterial capsule was well distributed within the prepared electrospinning membrane. The antibacterial test confirmed that glycyrrhizic acid encapsulated with β-cyclodextrin maintains its antibacterial properties. If such electrospun fiber containing an antibacterial capsule is manufactured, it can be applied to trauma treatment such as wound dressing due to its antibacterial effect. In addition, it can be used in various fields such as infection prevention and disease treatment by utilizing the anti-inflammatory and antiviral effects of glycyrrhizic acid. [ABSTRACT FROM AUTHOR]