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The paper explores strategies to enhance the energy storage efficiency (η) of relaxor- ferroelectric (RFE) ceramics by tailoring the structural parameter tolerance factor (t), which indicates the stability of a perovskite. KTaO3 (KT) with a t of 1.054 has been selected to modulate the t value of 0.75Bi0.5Na0.5TiO3-0.25BaTiO3 (BNT-BT, t = 0.9967), and a serials of (1 − x)(BNT-BT)-xKT (x = 0–0.10) RFE ceramics with t from 0.997 to 1.003 have been prepared. Structural analyses show that all the ceramics possess typical perovskite structure, and the average grain size decrease with the addition of KT. The tested dielectric characteristics present that with the increase of t to 1, the diffuse-phase-transition peak is gradually diminished in the dielectric constant vs temperature (εr-T) curves, while the relaxation-dielectric behavior is gradually strengthened, and the temperature stability of the dielectric constant is improved. The breakdown strength is also enlarged with the increase of KT content. As a result, the 0.94(BNT-BT)-0.06KT with t = 1.0004, which is closest to 1, achieving a recoverable energy storage density (Wrec) of 4.9 J/cm3 and η of 91.8% at 336 kV/cm, which are 191.7% and 49.5% higher than the Wrec (1.68 J/cm3) and η (61.4%) of pure 0.75BNT-0.25BT ceramic, respectively. These findings offer a promising approach for enhance the energy storage properties of RFE ceramics. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF) film shows great potential for applications in the electrostatic energy storage field due to its high dielectric constant and breakdown strength. Polymer film surface engineering technology has aroused much concern in plastic film capacitors as an effective strategy for improving dielectric properties and energy storage characteristics. In this paper, biaxially oriented PVDF (BOPVDF) films were prepared by melt extrusion-biaxial stretching and treated with organic impregnation using hydrofluoroether. The insulation properties and energy storage density of the biaxially oriented films were significantly improved by a simple film formation post-treatment. The impregnation treatment effectively suppressed the leakage current of the film at a high electric field. The impregnated BOPVDF exhibited excellent insulation properties with a breakdown strength of 747.84 kV/mm. Meanwhile, the energy storage density of 16.26 J/cm3 with a charge–discharge efficiency of 78.41% was obtained at 700 kV/mm. This research provided a simple way to improve the energy storage performance of PVDF-based polymers by organic impregnation treatment and has the feasibility of achieving large-scale production. [ABSTRACT FROM AUTHOR]

This paper studies the chattering-free sliding mode control problem for the discrete-time Markov jump unmanned surface vehicle systems under denial-of-service attacks. An event-triggered mechanism is employed to reduce the waste of energy and alleviate bandwidth restriction. In the sliding phase, an observer-based sliding mode surface and an equivalent control law are proposed to address the finite-time boundedness problem of the Markov jump unmanned surface vehicle systems. In the reaching phase, a chattering-free sliding mode controller is designed to ensure that the state trajectories of the Markov jump unmanned surface vehicle systems can be driven onto the sliding mode surface. With the help of Lyapunov functions, sufficient conditions are derived to guarantee the finite-time boundedness and the H ∞ performance of the switched Markov jump unmanned surface vehicle systems. In the simulation part, an application of the unmanned surface vehicle is utilized to verify the practicality of our proposed control method. [ABSTRACT FROM AUTHOR]

This study investigates the optimization of the charge plan in casting heat treatment. The optimization problem is formulated as a 0-1 integer programming model aiming at maximizing the utilization of the furnaces, minimizing the holding temperature differences and the overall delivery deadline of castings in a furnace. To approach the mathematical model, a two-steps solution methodology is designed. First, the feasible casting candidate sets are generated in consideration of the holding temperature and cooling mode constraints. Then, an improved backtracking search algorithm (IBSA) is proposed to obtain optimal charge plan for each feasible candidate set. The best one among the optimal charge plans obtained by IBSA is selected as the final charge plan. In IBSA, a mapping mechanism is applied to make original backtracking search algorithm (BSA) suitable to discrete problems. Improvements that consist of the modification of historical population updating mechanism, the hybrid of mutation and crossover strategy of difference evaluation algorithm, a greedy local search algorithm and the re-initialization operator are also made to enhance the exploitation and exploration ability of IBSA. The comparisons of simulation experiments demonstrate the effectiveness of the proposed model and the performance of the proposed algorithm. [ABSTRACT FROM AUTHOR]

The ultra-precision components with freeform surfaces are used in a wide range of areas such as automotive, aerospace, optical, metrology artifacts, and data storage. Fast tool servo (FTS) diamond turning has been considered as one of the leading techniques to produce such components. We present four points mean value interpolator for FTS diamond turning. Performance is compared between the NURBS interpolations with the proposed interpolation using Matlab, which shows that the proposed interpolation not only improves the surface accuracy of the freeform surface, but also meets the real-time requirement. [ABSTRACT FROM AUTHOR]

Multiple nano-sized α-Ni(OH) was synthesized by ultrasonic-assisted precipitation under different conditions. The crystal structure and particle size distribution of the sample were characterized with X-ray diffraction (XRD), infrared spectroscopy, and laser particle size analyzer (PSA). The results show that the samples are anisotropic polycrystalline of α and β Ni(OH), and the ratio of α and β changes with the difference of nickel source, resulting in the largest ratio of α-Ni(OH) using nickel nitrate as reactant. Larger amount of NaCO is conducive to the formation of α-Ni(OH); while the resultant phases are all β with the same conditions but no doping. The results of PSD indicate that the samples are about 100-120 nm in size, and the sample with nickel sulfate as nickel source has the minimum particle size. The three ions of nickel source appear in the absorption peaks in the Fourier transform infrared spectrum showing that the ions change the crystal structure of Ni(OH). EDS testing shows that Y and anion distribute in the lattice of α-Ni(OH) uniformly. [ABSTRACT FROM AUTHOR]

Mutations of p53 cause not only loss of wild-type function but also gain of novel oncogenic functions (GOF). Accumulating evidence suggest that p53 hotspot mutations may confer different types and magnitudes of GOF. Here we add support to the heterogeneity of mutant p53 GOF by showing their unequal association with early tumor onset and spectrum of tumor types. We stratified Li-Fraumeni syndrome (LFS) patients according to carried p53 mutations using data from the updated p53 germline mutation database. When compared to loss-of-function nonsense mutations, the R282 GOF mutation associated with significantly earlier onset, while the G245 mutation displayed later onset. The R175, Y220, R248, R282 and nonsense mutations showed preferential distribution in certain cancer types, which varied in the age of onset. Multivariate COX regression model adjusting for cancer types and patient sex suggested that nonsense and G245 mutations had lower risk than R248 for early onset, suggesting unequal strengths of mutant GOF effects. Our results suggest that Li-Fraumeni syndrome can be subdivided into subtypes linking to unequal GOF effects of p53 mutations. These findings have potential implications in the prevention, early detection and targeted treatment of LFS tumors. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) participate in diverse biological pathways and may act as oncogenes or tumor suppressors. Single nucleotide polymorphisms (SNPs) in miRNAs (MirSNPs) might promote carcinogenesis by affecting miRNA function and/or maturation; however, the association between MirSNPs reported and cancer risk remain inconsistent. Here, we investigated the association between nine common MirSNPs and cancer risk using data from large scale case-control studies. Eight precursor-miRNA (pre-miRNA) SNPs (rs2043556/miR-605, rs3746444/miR-499a/b, rs4919510/miR-608, rs2910164/ miR-146a, rs11614913/miR-196a2, rs895819/miR-27a, rs2292832/miR-149, rs6505162/miR-423) and one primary-miRNA (pri-miRNA) SNP (rs1834306/miR-100) were analyzed in 16399 cases and 21779 controls from seven published studies in eight common cancers. With a novel statistic, Cross phenotype meta-analysis (CPMA) of the association of MirSNPs with multiple phenotypes indicated rs2910164 C (P 5 1.11E-03), rs2043556 C (P 5 0.0165), rs6505162 C (P 5 2.05E-03) and rs895819 (P 5 0.0284) were associated with a significant overall risk of cancer. In conclusion, MirSNPs might affect an individual's susceptibility to various types of cancer. [ABSTRACT FROM AUTHOR]

Given the increasing notion of target promiscuity of bioactive compounds and polypharmacological drug behavior, a detailed analysis of publicly available compound activity data from medicinal chemistry sources was carried out to determine and quantify the degree of promiscuity of active compounds across all known human target families. The results are surprising. Approximately 62% of currently available compounds with high-confidence activity data are only annotated with a single biological target, whereas 36% are known to act against multiple targets within the same family (i.e., closely related targets). However, only ~2% of bioactive compounds are promiscuous across different target families. Thus, despite general data sparseness, these findings indicate that highly promiscuous bioactive compounds only rarely occur. Because pharmaceutically relevant active compounds represent the pool from which drug candidates emerge, one might extrapolate from these results and conclude that there is a low statistical probability to obtain drugs that act against multiple targets belonging to distinct families. [ABSTRACT FROM AUTHOR]

A recent analysis of structure and target relationships between current drugs and bioactive compounds has revealed that only a small fraction of drugs that are active against the same or overlapping targets are involved in substructure relationships and/or share the same topology. By contrast, structurally related drugs displayed a tendency to preferentially act against different targets. For bioactive compounds, opposite trends were observed. These surprising findings arising from the global analysis have now been examined in detail by analyzing structure and target relationships between drugs at the level of individual targets and individual drugs and by comparing the results of local (target- or drug-based) and global relationship analysis. On the basis of target-based analysis, on average, only 14% of drugs active against a given target form well-defined structural relationships. In addition, drug-based analysis revealed that on average 72% of all structurally related drugs have no or at most 20% target overlap. Taken together, the results of our current analysis at the level of single targets and drugs rationalize their unexpected structure and target relationships in a consistent manner. These findings also have implications for ligand binding characteristics of popular drug targets and for frequently observed polypharmacological drug behavior. [ABSTRACT FROM AUTHOR]

Thermal protection of firefighter protective clothing is greatly influenced by the air gap entrapped and moisture in clothing. In this paper, the effects of air gap size and position on thermal protective performance exposed to 84 kW/m heat source were investigated. Water was also added to thermal liner to understand the effect of air gap coupled with moisture on thermal protection. It was indicated that the TPP of fabrics system increased with the air gap size. The air gap position also greatly influenced the heat transfer during exposure to flash fire. Moisture added weakened the positive effect of air gap size when the air gap exists far from heat source, and almost eliminated the favorable effect of air gap position. However, when there is no air gap or small air gap between outer shell fabric and moisture barrier, moisture increased the thermal protection performance of multilayer fabrics system. The results obtained suggested that certain air gap entrapped in fabrics system and clothing microclimate could improve thermal protection, and the complicated effect of moisture should also be considered. [ABSTRACT FROM AUTHOR]

It's urgent to investigate moisture effect on thermal protection of thermal protective clothing in simulated fire scene as accurately as possible. The current bench top tests can't evaluate thermal protective performance (TPP) of fabrics under microclimate with high temperature and relative humidity (RH). In this paper, to well investigate effect of different RH under microclimate on thermal protective performance of flame-retardant fabrics exposed to flashover, a new modified TPP testing apparatus was developed. It consisted of a typical TPP tester and RH adjustable microclimate chamber. Three kinds of air gaps under fabrics were also employed to simulate different spaces between skin and clothing. The results showed that the temperature increment under microclimate of 35 % RH was highest, and that of 95 % RH was lowest. There was significant temperature difference found among above three adjusted environment. Time required of temperature rise to 12 oC highly prolonged as RH became higher. It could be deduced that the effect of RH on heat transfer became significant as air gap increasing; if the air gap width still increased, the moisture effect diminished. The newly developed testing apparatus could be well used to evaluate the moisture effect on thermal protective performance of flame-resistant fabrics. [ABSTRACT FROM AUTHOR]

SLAM is one of the most important components in robot navigation. A SLAM algorithm based on image sequences captured by a single digital camera is proposed in this paper. By this algorithm, SIFT feature points are selected and matched between image pairs sequentially. After three images have been captured, the environment’s 3D map and the camera’s positions are initialized based on matched feature points and intrinsic parameters of the camera. A robust method is applied to estimate the position and orientation of the camera in the forthcoming images. Finally, a robust adaptive bundle adjustment algorithm is adopted to optimize the environment’s 3D map and the camera’s positions simultaneously. Results of quantitative and qualitative experiments show that our algorithm can reconstruct the environment and localize the camera accurately and efficiently. [ABSTRACT FROM AUTHOR]

The paper reports on a study of the weak sandstones of the Shihti and Kweichulin Formations to the east of Taipei, Taiwan. The results indicate that the wave velocity and uniaxial compressive strength (UCS) of the samples decreased as water content increased, while wave velocity, UCS and slake durability increased with increasing porosity. Regression analyses demonstrated that wave velocity, UCS and slake durability decreased with increased quartz content. The values of these engineering properties also increased with a higher proportion of matrix/detritus, although the exact nature of the interrelationships between these factors is not clear. [ABSTRACT FROM AUTHOR]

Indoor volatile organic compounds (VOCs) have been associated with asthma, but there is little epidemiologic work on ambient exposures, and no data on relationships between respiratory health and exhaled breath VOCs, which is a biomarker of VOC exposure. We recruited 26 Hispanic children with mild asthma in a Los Angeles community with high VOC levels near major freeways and trucking routes. Two dropped out, three had invalid peak expiratory flow (PEF) or breath VOC data, leaving 21. Children filled out symptom diaries and performed PEF maneuvers daily, November 1999-January 2000. We aimed to collect breath VOC samples on asthma episode and baseline symptom-free days, but six subjects only gave samples on symptom-free days. We analyzed 106 breath samples by GC-MS. Eight VOCs were quantifiable in >75% of breath samples (benzene, methylene chloride, styrene, tetrachloroethylene, toluene, m,p-xylene, o-xylene, and p-dichlorobenzene). Generalized estimating equation and mixed linear regression models for VOC exposure-response relationships controlled for temperature and respiratory infections. We found marginally positive associations between bothersome or more severe asthma symptoms and same day breath concentrations of benzene [odds ratio (OR) 2.03, 95% confidence interval (CI) 0.80, 5.11] but not other breath VOCs. Ambient petroleum-related VOCs measured on the same person-days as breath VOCs showed notably stronger associations with symptoms, including toluene, m,p-xylene, o-xylene, and benzene (OR 5.93, 95% CI 1.64, 21.4). On breath sample days, symptoms were also associated with 1-h ambient NO2, OR 8.13 (1.52, 43.4), and SO2, OR 2.36 (1.16, 4.81). Consistent inverse relationships were found between evening PEF and the same ambient VOCs, NO2, and SO2. There were no associations with O3. Given the high traffic density of the region, stronger associations for ambient than for breath VOCs suggest that ambient VOC measurements were better markers for daily exposure to combustion-related compounds thought to be causally related to acute asthma. Alternatively, the low sample size of symptom responses (15-21 responses per 108 breath samples) may have led to the nonsignificant results for breath VOCs.Journal of Exposure Analysis and Environmental Epidemiology (2003) 13, 348-363. doi:10.1038/sj.jea.7500287 [ABSTRACT FROM AUTHOR]