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In this study, intrinsic Ga2O3 (i-Ga2O3) film was deposited at about 80 K using a vapor cooling condensation system. Its bandgap energy was 5.0 eV. Low oxygen vacancy and defects were verified by using photoluminescence and Hall measurements. When a 40-nm-thick i-Ga2O3 film was used as the gate dielectric layer of AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMTs), threshold voltage, and gate breakdown voltage were − 3.5 V and − 538.0 V, respectively. The associated gate leakage current of the devices operating at a gate-source voltage of − 100 V was 0.57 μA. Furthermore, a saturation drain-source current of 186.2 mA/mm and a maximum extrinsic transconductance of 85.8 mS/mm were obtained for the devices operating at a gate-source voltage of 0 V and a drain-source voltage of 10 V. The unit gain cutoff frequency and the maximum oscillation frequency were 5.7 GHz and 11.0 GHz, respectively. The normalized noise and Hooge’s coefficient were 3.79 × 10−14 Hz−1 and 5.06 × 10−5, respectively, when the devices operated at a frequency of 100 Hz, with a drain-source voltage of 1 V and a gate-source voltage of 5 V.

Background: Gold nanoparticles (AuNPs) have been widely used as local surface plasmon resonance (LSPR) immunoassay for biomolecule sensings. It is primarily based on two conventional methods - absorption spectra and colorimetric. While the low figure of merit (FoM) of the LSPR and high-concentration AuNPs requirement restrict their limit of detection (LOD), which is around ng to μg per mL in antibody detection if there is no other signal or analytes amplification. By now, the improvement of sensitivity has bogged down for years. It also reveals a great challenge of the current LSPR immunoassay in biosensing - pushing the boundary of the current LOD.Results: In this work, we developed a spectral image contrast-based flow digital nanoplasmon-metry(FDNM) to push the LOD boundary. Comparing the scattering image brightness of AuNPs in two neighboring wavelength bands near the LSPR peak, the signal of peak shift is extremely amplified and quickly detected. Introducing the digital analysis, the FDNM provides an ultra-high signal-to-noise ratio and less sample volume requirement. Compared to conventional analog LSPR immunoassay, FDNM has a LOD down to 1 pg mL-1 within only a 15-minute detection time and 500 μL sample volume. Antibody against spike proteins of SARS-CoV-2 in artificial saliva that contained various proteins was also conducted to validate the detection of FDNM in complicated samples. Of the detection, FDNM shows significant discrimination with a LOD of 10 pg mL-1 and a broad dynamic detecting range of five orders of magnitude. Conclusion: Together with the quick readout time and simple operation, this work outstandingly demonstrated the high sensitivity and selectivity of the developed FDNM in rapid antibody detection. The spectral image contrast and digital analysis further provide a new generation LSPR immunoassay of AuNPs.

This study utilizes a Taguchi-based particle swarm optimization algorithm to search an optimal four-stage constant current charge pattern for delivering the maximum capacity to provide long runtimes within the shortest charging time. The goal is to maximize the cost function for the applied charge pattern based on the charging time and discharge capacity ratio that both share the same weight. The discharge capacity ratio is defined as the total capacity of a cell discharged at a constant current of 0.3 C using the four-stage constant current charging strategy until reaching the preset voltage of 3.0 V to the one employs the constant current constant voltage charging method. The charging time is the overall charging duration of the 4SCC charging process. Sanyo UR14500P batteries in the cylindrical shape with a nominal voltage of 3.7 V and a rated capacity of 840 mAh are tested. In the tests, the optimal 4SCC sequence of 1.262 C, 1.082 C, 0.662 C and 0.258 C is allowed to charge the battery up to 94.7% of the nominal capacity for 67 min, and the constant current constant voltage charging arrangement of 0.7 C to 4.2 V and the cut-off of 0.05 C are used to charge the battery up to 99.5% of the nominal capacity in 119 min.

Polyaniline (PANI) is one of the most attractive materials for pseudocapacitors. To enhance the electrolyte diffusion and improve the electrochemical performance of the electrode, the well-designed morphology of PANI is required. Incorporating carbon materials is also benefic on enhancing the cycling stability as well as the mechanical and electrochemical properties of PANI. In this study, a simple solution method is applied to synthesize the particle-deposited tube-like PANI. Due to the well-defined structure, a specific capacitance (CF) of 437.8 F/g is achieved at the current density of 4 A/g. Furthermore, the self-synthesized graphene oxide (GO) is simply mixed with the particle-deposited tube-like PANI to make a more efficient electrocapacitive material. An enhanced CF value of 475.0 F/g is achieved for the optimized PANI/GO electrode, owing to the synergic effects of the pseudo-capacitance from PANI and the functional groups of GO, as well as the electrochemical double-layered capacitance from GO. After conducting 2000 cycles repeated charge/discharge process, the CF retention of 90% and the average Coulombic efficiency of higher than 90% are also attained for the optimized PANI/GO electrode.

Thin films of Fe rich FeRh were prepared by using DC magnetron sputtering from a Fe67Rh33 target onto MgO (0 0 1) substrate. In particular, here we identify a unique exchange-bias phenomenon. This is one of the homogenous system to have an exchange bias phenomena without the presence of two layer system with well-defined interface of ferromagnetic (FM)/antiferromagnetic (AFM) layers. Meanwhile, annealing at higher temperatures resulted in ordering of FeRh alloy which in turn gives rise to a higher exchange bias strength. Possible scenario for the exchange bias should have occurred from the boundaries between AFM/FM domains which could be due to the formation of AFM domain inside of FM matrix or vice versa in our single layer thin film.

This study reports on morphology dependent antibacterial activities of CuxO/ZnO nanocomposites towards Escherichia coli. The CuxO/ZnO nanocomposites were formed by aqueous photoreduction of CuxO nanostructures on solution grown ZnO nanorods on Si substrates. By controlling the photoreduction time and temperature, various CuxO nanostructures including nanocubes, nanoclusters, nanospikes, and nanowebs were created as verified by scanning electron microscopy. X-ray diffraction analysis reveals the good crystallinity of the ZnO nanorods. X-ray photoelectron spectroscopy confirms the successful deposition of CuO and Cu2O nanostructures on the nanorods. Antibacterial tests were performed in dark and under low-intensity blue-light irradiation. The nanoweb sample has an antibacterial efficiency of 95.8% for 10 min in dark and the nanospike sample has an efficiency of 99.5% for 10 min under light. For the nanospike sample, remarkable bacterial survival ratios of 3 × 10–4 and 10–5 in dark and under light both for a 60 min reaction time, respectively, have been achieved. The excellent antibacterial performance is attributed to combined effects of mechanical piercing of ZnO nanorods, release of Zn2+, Cu2+, and Cu+ ions, and effective generation of reactive oxygen species due to charge separation.

Low-cost counter electrodes for dye-sensitized solar cells (DSSCs) are prepared using platinum/carbon black (Pt/CB) composites via a spin-coating process. Ethyl cellulose (EC) is used as a binder to regulate the viscosity of the Pt/CB composites to facilitate the spin-coating process. The ratio of Pt to CB is ca. 1:3. The effects of film composition (Pt/CB:EC = 30:15, 30:4) and number of coating layers on the electrochemical properties of the Pt/CB electrodes and the performance of the corresponding DSSCs are studied. The results show that Pt/CB films with the lower concentration of EC (Pt/CB:EC = 30:4) exhibit high electrochemical activity, low charge transfer resistance, and good DSSC performance. These results are attributed to the lower loading of EC, which facilitates the charge transfer of the electrodes. DSSCs using these Pt/CB composite counter electrodes with lower loading of EC achieve a high conversion efficiency (8.06%) comparable to that of cells using Pt.

Ion-sensitive field - effect transistor (ISFET) biosensors were fabricated with a pH-sensitive Ba x Sr 1−x TiO 3 membrane on silicon substrates in an Electrolyte-Insulator-Semiconductor (EIS) structure. To investigate the effects of annealing in N 2 ambient, multiple material analyses including XRD and AFM were performed. Results indicate that the annealing treatment might deteriorate the crystallization. Therefore, the sensing behaviours in terms of sensitivity, linearity, hysteresis effects, and drift rates might be worsened. In this research, Ba x Sr 1−x TiO 3 membranes in an EIS structure with a high sensitivity and linearity were made. However, owing to its special and complicated structures, high-temperature thermal annealing was not suitable for the Ba x Sr 1−x TiO 3 membrane to further boost its sensing capability.

Developing cost-effective and fast detection methods in full-field optical coherence microscopy (FF-OCM) platform for biological applications is of prime focus today. In this paper, we report a cost-effective Linnik type FF-OCM system with a single broadband white light emitting diode (WLED) (470-850 nm, λ0 = 630 nm) light source in conjunction with a derivative-based image reconstruction algorithm. Sequential 2-D multiple phase-shifted interferograms were obtained by moving the sample stage using piezoelectric transducer and recorded via a 2-D charge complementary oxide semiconductor camera. Subsequently, the en-face sectional images were reconstructed using a derivative-based algorithm. The measured axial and lateral resolutions along with interferometric phase stability of the system were 0.9 μm, 1.4 μm, and 11 mrad, respectively. The advantages of the derivative-based algorithm over 4-step phase shifted method were demonstrated using USAF target and onion as test samples. Moreover, studies via the present system of the microstructure of skin epidermis in mouse ear with melanoma showed a significant deterioration from normal mouse skin in stratum corneum of the epidermis. This is the first study of the application of a derivative-based algorithm for biological samples in FF-OCM wherein WLED is used as a light source. The present system is stable, compact, and cost-effective compared to the conventional FF-OCM systems and provides comparable spatial resolution.

In this work, the adsorption/desorption kinetics of ZnO nanorods with two different levels of defects for UV-activated NO2 gas sensing at room temperature is investigated. It is found that the pristine ZnO has higher sensitivity than the thermally annealed ZnO and the consequence can be attributed to the presence of more oxygen vacancies that act as adsorption sites. Based on the Langmuir adsorption model, the adsorption and desorption constants are determined to be 2.7 × 10–5 ppb−1 s−1 and 3.2 × 10–3 s−1, respectively, for the pristine ZnO; and 1.5 × 10–5 ppb−1 s−1 and 2.1 × 10–3 s−1, respectively, for the annealed ZnO. Both kinetic constants for the pristine ZnO are higher, which manifests its higher sensitivity. The determination of kinetic constants could provide valuable information for better understanding of nanomaterials based gas sensors.

Carbon black (CB) thin films are prepared using a doctor blade process and utilized as counter electrodes (CEs) of dye-sensitized solar cells (DSSCs). Poly(vinylidene fluoride) (PVDF) is used as a binder to regulate the viscosity of the CB paste to facilitate the doctor blade process. The PVDF is then removed via thermal treatment at 350 or 450 °C. The effects of CB composition (8-15 wt%) and the heat-treatment temperature on the electrochemical properties of the CB electrodes are studied, as well as on the performance of the corresponding DSSCs. The results show that, after the heat treatment, all CB films demonstrate a mesoporous structure. Film thickness increases with increased CB concentration. CB films heat-treated at 350 °C exhibit low electrochemical activity, high charge transfer resistance, and poor performance when utilized in DSSCs. These results are attributed to the presence of residual PVDF. By elevating the treating temperature to 450 °C, PVDF is completely removed and the electrochemical properties of the resultant CB films resemble closely those of platinum (Pt) film. The DSSCs using these CB CEs achieve conversion efficiencies (8.27–8.35%) comparable to cells using Pt (8.29%).

ZnO structures were electro-hydrothermally grown on copper and silver wires. To characterize the structures, multiple analyses including field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and photoluminescence measurements were performed on the ZnO structures on the wires. Results indicate that ZnO nanoflakes were densely deposited on the silver wire but poor ZnO structures were grown on the copper wire. Furthermore, OD 600 antibacterial tests revealed that ZnO flakes on the silver wire exhibited better antibacterial capability than the silver wire without ZnO nanoflakes. Because of possible integration with silver-related materials and flexibility of wire structures, ZnO nanoflake-coated silver wires have potentials for future antiseptic and biomedical applications.

Bimetallic nanoparticles (NPs) have received increasing attention for their outstanding catalytic activity which the corresponding monometallic NPs can hardly achieve. In this paper, we developed a facile approach to prepare Se-supported Au/Pd NPs with high and photo-assisted electrocatalytic activity. Cyclic voltammetry (CV) measurements showed that the electrocatalytic activity of the Se-supported Au/Pd NPs was dependent on the Pd content. This result indicates that the interface between Pd and Au plays a vital factor in the electrocatalytic activity, while the individual metal components in the Se/Au/Pd system are of minor relevance for such activity. The Se-supported Au/Pd NPs exhibited mass activities of 4.25 (A/mg Pd ) and 1.21 (A/mg Au+Pd ) toward ethanol oxidation, which were higher than that of the commercial Pd/C catalyst (0.36 A/mg Pd ). The electrocatalytic activity of Se-supported Au/Pd NPs was further enhanced by 2.4 times under solar light irradiation due to the photoelectrochemical effect of the Se NPs. It was further demonstrated in this paper that the presence of Se-supported Au/Pd NPs is crucial in self-powered electrochemical sensing systems as the overall sensitivity is significantly improved.

In recent years, the use of triboelectric nanogenerators (TENGs) has become an effective technique to harvest mechanical energy based on contact electrification and the electrostatic effect. However, the electric output of TENGs decreases in environments with high relative humidity (RH), which restricts their application. The reason for this phenomenon is that charge transfer in most TENGs occurs through an electron pathway. By using gelatin/glycerol and polytetrafluoroethylene (PTFE) as triboelectric layers to construct a biocompatible TENG, we found that the electric output of the TENG can be maintained or is even enhanced at higher RH. The hydration of amino groups in gelatin resulted in additional charges (mobile ions) on the triboelectric layers during the contact electrification process, consequently increasing the electric output of the TENG. The electric output generated from the TENG increased 2-fold when the RH was increased from 20% to 60%. By using genipin to react with the amino groups in gelatin, the formation of mobile ions was blocked and the measured charge density on the triboelectric layers decreased as the RH gradually increased. We also demonstrated that the change of electric output generated from the TENG could be applied as a tool to detect RH, exhibiting the superior stability and durability of the TENG. This study also leads to a fundamental understanding of the mechanism of contact electrification when using protein as the triboelectric layer.

ZnO nanorods (NRs) incorporating a graphene layer were fabricated on silicon substrates. The graphene layer was placed on top and bottom of ZnO to form graphene/ZnO NRs/Si and ZnO NRs/graphene/Si nanocomposites. To characterize these nanocomposites, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were used, as well as contact angle measurements to study hydrophilic properties. Finally, OD600 bacterial growth tests were performed to investigate the bacterial suppression capabilities. Results indicate that the ZnO NRs/graphene/Si nanocomposite exhibits the strongest bacterial suppression capability among the studied nanostructures.

A collagen solution was added as a joint-lubricating fluid to extend the service life of UHMWPE liners. Adding this solution could effectively increase the adsorption of collagen onto zirconia surfaces, thereby reducing grinding parts (UHMWPE) wear. In this experiment, the thermal denaturation properties of collagen were used to manipulate the structural state of collagen molecules. The resulting structural alterations were observed using Fourier transform infrared spectroscopy, which indicated that the molecular structure of collagen changed from a triple-helix structure to a disordered molecular structure due to thermal effects. Collagen adsorption experiments also demonstrated that helical collagen molecules displayed higher rates of adsorption than disordered collagen molecules. Actual wear tests showed that larger quantities of adsorbed collagen led to lower friction coefficients and wear.

Zirconia and ultra-high molecular weight polyethylene (UHMWPE) are common materials for artificial joints. However, the failure of artificial joints is mainly caused by the wear of UHMWPE. Therefore, the development of effective measures to enhance the service life of UHMWPE is one of the most important facets of research on total joint replacement. The purpose of this study is to use an atmospheric-pressure plasma system to modify zirconia and UHMPWE surfaces, which is expected to increase the adsorption of joint-lubricating fluids, thus reducing the abrasion and wear of UHMWPE (73% improvement). Surface modification experiments were carried out using an atmospheric-pressure plasma system, while fourier transform infrared spectroscopy was used to characterize the surfaces treated with atmospheric-pressure plasma. The results of water contact angle tests indicated that the plasma-treated material surfaces exhibited excellent hydrophilicity (70% improvement). In addition, the treatment of materials with atmospheric plasma was confirmed to increase the adsorption of lubricating fluid and reduce wear, thus extending the service life of UHMWPE.

Poly (vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP) and poly (acrylonitrile-co-vinyl acetate) (PAN-VA) are used as gelator to prepare gel- and solid-state polymer electrolytes for dye sensitized solar cells (DSSCs) applications. The electrolytes prepared using PVDF-HFP have higher conductivities than those prepared using PAN-VA. In blended polymers, the conductivities of the electrolytes increase with increasing composition of PVDF-HFP; at 75% PVDF-HFP, conductivity of the blended polymer surpassed that of pure polymers. It is also found that the viscosity of the electrolyte prepared by PAN-VA (1.2 kPaS) is much lower than that by PVDF-HFP (11 kPaS). Therefore, increasing PAN-VA composition can decrease the viscosity of the electrolyte, improving the penetration of electrolytes in the TiO2 matrix. By controlling the ratio of PVDF-HFP/PAN-VA, the conductivity and viscosity of the electrolyte can be regulated and an optimal ratio based on the conversion efficiency of the gel- and solid state DSSCs is obtained at the ratio of 3/1. The highest efficiency achieved by the gel- and solid-state cells using the blending polymers are 6.3% and 4.88%, respectively, which are higher than those prepared using pure polymers (5.53% and 4.56%, respectively). The introduction of TiO2 fillers to the solid electrolyte can further increase the cell efficiency to 5.34%.

In this investigation Zr-based (Zr 51 Cu 31 Al 3 Ni 5 ) and Ti-based (Ti 40 Zr 10 Cu 8 Nb 7 Co 7 ) thin-film metallic glass (TFMG), in different thickness, were used to improve the tribological properties of 7075 aluminum alloy substrates with different surface patter. Wear tests were performed in refrigerator oil to evaluate the effect of thin film adhesion strength and surface pattern on the wear resistance. A scanning electron microscope (SEM) with energy dispersive spectrometer (EDS), nanoindenter and scratch tester were used to analyze the metallurgical and mechanical properties of the specimens. The stress distribution of TFMG on the 7075 aluminum alloy substrates under line contact condition was evaluated by ANSYS. According to the experiment results, wear resistance of the sample that was coated with a 200nm-thick Ti-based was better than the other coated samples, because surface texture can increase mechanical locking effect to enhance adhesive strength, and Ti-based thin film coating can improve tribological performance and reduce wear loss.

In their original forms, carbon nanotubes (CNT) are spatially entangled. To make CNT papers (CNTPs), the CNT agglomerates must be dispersed and re-entangled into a planar sheet. The processing characteristics are very different from those of traditional buck-form nanocomposites. This article examines the processing, micro-structures, and failure behavior of the CNTP composites. The CNTPs were first made by a dispersion and filtering process. Then, an epoxy resin was added into the CNTP by using a vacuum bag method. Different CNT weights were employed to make the CNTPs with different thicknesses and areal weights. The CNTP allows direct resin impregnation along the thickness direction and avoids the difficulty of dispersing CNTs in the viscous resin. The CNT content can be much higher than that attainable in traditional bulk CNT composites. Both tensile and tearing tests were conducted, and the fracture behaviors were examined. POLYM. COMPOS., 2014. © 2014 Society of Plastics Engineers

A novel copolymer, poly(acrylonitrile- co -vinyl acetate) (PAN-VA), is used as the solidification agent to prepare solid-state redox electrolytes for dye-sensitized solar cell (DSSC) applications. TiO 2 nano-particles are used as the fillers to enhance the performance of the solid electrolytes. Furthermore, to improve the penetration of solid electrolytes in the mesoporous TiO 2 matrixes, an external pressure is applied on the electrodes during the solvent evaporation process. The results show that the ionic conductivities of the solid-state electrolytes are comparable with those of gel electrolyte, indicating that the PAN-VA matrix itself may contribute to the charge transfer through the Grotthuss charge transfer mechanism. Based on the temperature-controllable viscosity of the polymer electrolytes, as well as the effect of an applied force, the solid electrolyte can penetrate well in the TiO 2 film, making good contact with the photoelectrode. It is also found that the introduction of TiO 2 fillers does not affect the conductivity of the electrolyte, but greatly enhance the charge transfer at the interface of the electrolyte and Pt counter electrode. On based of the high performance of the electrolyte system, an energy conversion efficiency of 8.65% is achieved for the solid-state DSSC.

Antimicrobial peptides (AMPs) are important components of the host innate defense mechanism against invading microorganisms. Although AMPs are known to act on bacterial membranes and increase membrane permeability, the action mechanism of most AMPs still remains unclear. In this report, we found that the TP4 peptides from Nile tilapia anchored on E. coli cells and enabled them permeable to SYTOX Green in few minutes after TP4 addition. TP4 peptides existed in small dots either on live or glutaraldehyde-fixed cells. TP4 peptides were driven into oligomers either in soluble or insoluble form by a membrane-mimicking anionic surfactant, sarkosyl, depending on the concentrations employed. The binding forces among TP4 components were mediated through hydrophobic interaction. The soluble oligomers were negatively charged on surface, while the insoluble oligomers could be fused with each other or piled on existing particles to form larger particles with diameters 0.1 to 20 μm by hydrophobic interactions. Interestingly, the morphology and solubility of TP4 particles changed with the concentration of exogenous sarkosyl or trifluoroethanol. The TP4 peptides were assembled into oligomers on or in bacterial membrane. This study provides direct evidence and a model for the oligomerization and insertion of AMPs into bacterial membrane before entering into cytosol.

Graphene nanosheets (GNSs) are flake-like materials composed of few-layer graphene sheets. GNSs are similar to multi-walled carbon nanotubes (CNTs) in graphene structures and in layer numbers. However, GNSs and CNTs behave very differently in deformation and fracture. In this study, natural graphite flakes were employed to make expanded graphite (EG), which is composed of partially connected GNSs. Both sonication and three-roll milling were used to separate the GNSs and to disperse them into an epoxy resin. By compacting EG, the GNSs inside were compressed and deformed. By breaking the GNS/epoxy composite, most GNSs on the cracked surfaces were fractured. Both SEM and TEM have been used for microscopic observations. The micrographs revealed that folding and wrinkling are the major modes of deformation, while tearing and peeling are the dominant modes of fracture. These modes are virtually non-existent in CNTs. The factors to cause the different behavior are discussed.

The absorption coefficient at 1.4 eV is divided by the value at 0.9 eV to obtain the factor used to judge the quality of μc-Si:H. PV device performance can be predicted by multiplyingVocwithIscwhen using this layer as an intrinsic layer. The results show a good relationship between the quality factor and the product of open-circuit voltage and short-circuit current. However, the final efficiency is influenced by the identities of the interface in the multilayer structure.

Thermoplastic composites are eco-friendly to environment. In this study, PET/PP thermoplastic composite laminates were produced by interleaving polypropylene (PP) sheets with polyethylene terephthalate (PET) plain fabrics in the condition of varying thermocompression temperature, pressure and time. Afterwards, peel resistance, tensile and impact properties of PET/PP thermoplastic laminates were tested. And the tensile and impact performance of PET/PP laminates was respectively about 40 % and 320 % higher than PP laminates. It was shown that when thermal compressing under pressure of 40 Kg/cm2 at 230 °C for 0.5 minute, PET/PP thermoplastic laminates had optimum tensile and impact properties.

Fick's diffusion law is applied to a one-dimensional diffusion case in which moisture diffuses through both surfaces into a composite laminate submerged in water. The advancing boundary model is adopted to study the moisture diffusion depth and also the moisture content distribution in the laminate. The major contribution of this work is establishing the procedure to obtain the required parameters for quantifying the depth of diffusion and the moisture content distribution which are related to the induced real-time hygric strain and important to the design of a composite structure that is to be used in a marine environment.

The moisture expansion of composites exposed to humid air was investigated. Tests for moisture expansion were performed on carbon/epoxy laminates exposed to humid air of different relative humidity levels and temperatures. The expansion strain data were employed to derive the material's diffusivity and the saturated expansion strain. The result indicated that the saturated expansion strain is about proportional to the level of humidity and inversely proportional to absolute temperature. An algorithm was then employed to track moisture expansion of a laminate in air with varying humidity level based on the diffusivity and the saturated expansion strain. The theoretical predictions were confirmed experimentally.

This investigation attempts to characterize the material principal diffusivities of a unidirectional composite laminate. Diffusion of moisture in an orthotropic plate immersed in water conforms to Fick’s diffusion law. Assuming moisture absorption induces proportional hygric strain in the laminate, the hygric strain is expressed as a function of the moisture concentration that depends on the specimen geometry, material diffusivities, and diffusion duration. Immersion tests of unidirectional carbon/epoxy laminate were conducted, and suspension method was adopted to monitor continuously the hygric expansion of the specimen in water without retrieving it from water. Specimens of different dimensions were used. Data of the hygric strain verse immersion duration are used to derive the material diffusivities by least square curve fitting. The result indicates that the diffusivity in fiber’s longitudinal direction of unidirectional T700 carbon/epoxy laminate is much greater than that in the thickness direction, and also the deviations of the derived diffusivities are proportional to the square of the corresponding dimension (width or thickness).

Antimicrobial peptides are important components of the host innate defense mechanism against invading pathogens, especially for drug-resistant bacteria. In addition to bactericidal activity, the 25 residue peptide TP4 isolated from Nile tilapia also stimulates cell proliferation and regulates the innate immune system in mice. In this report, TP4 hyperpolarized and depolarized the membrane potential of Pseudomonas aeruginosa at sub-lethal and lethal concentrations. It also inhibited and eradicated biofilm formation. The in vitro binding of TP4 to bacterial outer membrane target protein, OprI, was markedly enhanced by a membrane-like surfactant sarkosyl and lipopolysaccharide, which converted TP4 into an α-helix. The solution structure of TP4 in dodecylphosphocholine was solved by NMR analyses. It contained a typical α-helix at residues Phe10-Arg22 and a distorted helical segment at Ile6-Phe10, as well as a hydrophobic core at the N-terminus and a cationic patch at the C-terminus. Residues Ile16, Leu19 and Ile20 in the hydrophobic face of the main helix were critical for the integrity of amphipathic structure, other hydrophobic residues played important roles in hemolytic and bactericidal activities. A model for the assembly of helical TP4 embedded in sarkosyl vesicle is proposed. This study may provide valuable insight for engineering AMPs to have potent bactericidal activity but low hemolytic activity.

Self-powered sensing systems that can work without external power sources have recently been demonstrated to detect pH, humidity, pressure, and temperature. By harvesting energy directly from the environment, these self-powered sensing systems are advantageous in minimizing the size, having long-term operation, and avoiding the use of toxic materials in battery. In this paper, we prepared Au/Pd nanomaterials as the nanocatalysts in the self-powered sensing systems. Au nanoparticles were synthesized first and served as the seeds for the growth of Pd component. The content of Pd component on the Au nanoparticles could be varied by reacting with different concentration of Pd2+ ions. Cyclic voltammetry indicated that the electrocatalytic oxidation of ethanol was dependent on the content of Pd component. Finally, we combined the as-prepared Au/Pd nanomaterials with a self-powered sensing system for ethanol detection. The self-powered ethanol sensor developed here could become a real sensing system in the futures.

By dividing the absorption coefficient at 1.4eV with the value at 0.9eV, we could judge the quality of μc-Si:H and predict (Voc*Isc) of solar cell when using this layer as its intrinsic layer.

We proposed the absorption coefficient ratio of (1.4 eV)/ (0.8 eV) as the quality factor of microcrystalline silicon thin films. It is convinced that a proportional relationship is between quality factor and solar cell efficiency.

Poly(acrylonitrile-co-vinyl acetate) (PAN-VA) is utilized as a gelation agent to prepare gel-state electrolytes for dye-sensitized solar cell (DSSC) applications. Based on the synergistic effect of PAN-VA and TiO(2) fillers in the electrolyte, the gel-state DSSC can achieve a conversion efficiency higher than that of a liquid counterpart. The high performance of the gel-electrolyte is attributed to the in situ gelation property of the gel-electrolyte, the contribution of the PAN-VA to the charge transfer, as well as the enhancement effect of TiO(2) fillers on the charge transfer at the Pt-electrolyte interface. The experimental results show that the efficiencies of the gel-state cells have little dependence on the conductivity of the electrolytes with various contents of PAN-VA, but are closely related to the penetration situation of the electrolyte in the TiO(2) film. For PAN-VA concentrations ≤15 wt%, the electrolyte can be easily injected at room temperature based on its in situ gelation property. For higher PAN-VA concentrations, good penetration of the high viscous electrolyte can be achieved by elevating the operation temperature. By utilizing a heteroleptic ruthenium dye (coded CYC-B11), gel-state DSSCs with an efficiency of above 10% are obtained. Acceleration tests show that the cell is stable under one-sun illumination at 60 °C.