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Ni 25 Ti 25 Hf 25 Cu 25 medium entropy shape memory alloy (MESMA) exhibit reversible B2↔B19′ martensitic transformation. Martensitic morphology is represented by (011) type I twins with low density of inner (001) compound twins. In a bending test, Ni 25 Ti 25 Hf 25 Cu 25 exhibits reversible strain of 2.4% under stress of 300 MPa. [Display omitted] • Ni 25 Ti 25 Hf 25 Cu 25 exhibits B2↔B19′ MT. • Low density of (001) compound twins into martensitic variants. • Recoverable strain of 2.4% under stress of 300 MPa. [ABSTRACT FROM AUTHOR]

Decarburization means carbon in rail material lost in the hot rolled process. It changes the microstructure of rail materials and will influence their rolling contact fatigue (RCF) characteristic. The objective of this study is to explore the effect of decarburized layer on rolling contact fatigue and propagation mechanism of crack under the wet condition using a rolling-sliding wear testing machine. The results show that the crack growth rate on the decarburized rail roller is over 4 times than that on the non-decarburized rail. Small pitting presents on the non-decarburized rail roller, which is dominated by transgranular crack. While, long mouth surface crack dominates on the decarburized rail roller and the cracks mainly grow along the ferrite line or the grain boundary. With the cycles increasing, the surface cracks of decarburized rail roller gradually break and forms spalling damage, eventually expands to bulk spalling. Meanwhile, the crack growth mechanism changes back to the transgranular propagation and propagates in depth with a large angle when the decarburization is worn off. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the nutrient composition and AME n content of corn distillers dried grains with solubles (DDGS) to develop prediction equations for AME n in laying hens. Ten samples of DDGS ranging in ether extract (EE) from 21.8 to 177.8 g/kg (DM basis) were selected and were subsequently fed to laying hens to determine AME n content. A total of 176 62-week-old laying hens (Lohmann-Pink) were placed in metabolic cages (2 hens/cage) and were allotted into 11 dietary treatments (8 cages per treatment) according to hen-day egg production. Dietary treatments included a corn-soybean meal reference diet and 10 test diets. Each test diet was created by mixing the reference diet with 200 g/kg one of 10 DDGS samples at the expense of the energy-yielding ingredients (139.6 g/kg corn, 59.0 g/kg soybean meal, and 1.4 g/kg rapeseed oil). Experimental diets were fed in the 7-day adaptation period, followed by the 4-day total excreta collection period. Gross energy (GE) and crude protein (CP) of the experimental diets and excreta were determined to calculate AME n for each DDGS sample. On the DM basis, AME n of the 10 corn DDGS samples ranged from 729 to 2535 kcal/kg. Analyses were conducted to determine the GE, CP, EE, DM, crude fiber, neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash content of the DDGS samples. Stepwise regression resulted in the following best-fit equation for AME n (DM basis) based on the coefficient of determination, SE, and the Mallows’ statistic (Cp): AME n , kcal/kg = 0.777 × GE (kcal/kg) − 5.39 × NDF (g/kg) (R 2  = 0.99; SE = 172; C p  = −3.37). These results suggested that the composition of corn DDGS may be used to predict AME n in laying hens. [ABSTRACT FROM AUTHOR]

Elastic-plastic response is greatly involved in the failure of wire ropes. Based on the derivation of the local deformation parameters of individual wire, an analytical model characterizing the elastic-plastic behavior for both wire strands and multi-strand ropes is developed in this paper. Also, the contact status within a multilayered strand is carefully studied to achieve a full understanding of wire stresses. Details of the surface strain fields of ropes are captured by 3D digital image correlation (3D-DIC) technique and the results agree well with the prediction of the present model. Varying loading conditions are considered to analyze the yielding and failure behavior of wire strands. It is found that the rotation of ropes (no matter its positive or negative) will increase the overall stress level over the wire cross section, however, restraining the rope ends leads to higher contact stress. Increasing the helix angle moderately may be an effective method to reduce the contact pressure of strand wires. Our model provides straightforward prediction of the elastic-plastic response of wire ropes and proves an effective tool for rope design due to a great reduction of time consuming in numerical simulations. [ABSTRACT FROM AUTHOR]

Uniaxial stress-controlled ratcheting behaviors of expanded PTFE (ePTFE) under cyclic compressive loads were tested. The effects of temperature, stress rate and mean stress on the ratcheting behaviors of ePTFE considering multiple load paths were discussed in detail. Results present that the steady ratcheting strain is rate-independent when the stress rate is less than about 0.1 MPa/s, while it approximately linearly decreases with increasing the stress rate for greater stress rate. Additionally, the steady ratcheting is temperature-independent when the temperature is greater than about 150 °C, but it nearly linearly increases with enhancing the temperature for lower temperature. Especially, the stress rate almost has little effect on the ratcheting strain of ePTFE at 200 °C. Moreover, the accumulated ratcheting strain enhances rapidly in about the first 80 cycles, and subsequently tends to shakedown in the subsequent cycles for each load path. Furthermore, if a higher stress is used in the prior cycling, the greater ratcheting strain may be produced, and a negative ratcheting strain rate can be obtained in the subsequent cycling with lower mean stress due to the greater strain hardening and deformation resistance produced by the previous higher stress. [ABSTRACT FROM AUTHOR]

When the thicknesses of the outer layers are different in sandwich rolling, based on the different kinds of arrangements with the hard and soft materials the thickness ratio of two outer layers is changed differently during the rolling process. After the first analysis of the different outer thicknesses sandwich rolling, the rules for final thickness ratio of the two outer layers are proposed. In soft–hard–soft sheets (s–h–s) the thickness ratio of outer layers is remained in the final bonded sandwich sheet however in hard–soft–hard sheets (h–s–h) the thickness ratio is alleviated by sandwich rolling itself. A model based on slab method is proposed to analyze this phenomenon and 4 groups of experiments with Al and Cu as well as steel are conducted. The results calculated by the model well agree with those measured in the experiments. Then the accuracy and worthy of the model are verified. [ABSTRACT FROM AUTHOR]

The study aimed to determine the ileal phosphorus (P) digestibility (iPD) and the excreta P retention (ePR) of 5 monodicalcium phosphate (MCP) samples and 3 dicalcium phosphate (DCP) samples in broiler chickens and in Pekin ducks using the substitution method. A total of 720, 21-d-old Arbor Acres broiler chickens in experiment 1 and 720, 15-d-old Pekin ducks in experiment 2 were randomly allocated to 9 dietary treatments with 8 replicate cages (10 birds/cage) based on the similar mean body weight, respectively. The collection of excreta (for 72 h after a 3-d acclimation) and ileal digesta (after 6 d of feeding experimental diets) was done. The results showed the average iPD/ePR of MCP and DCP for broilers were 83.11%/74.52% and 75.34%/69.46% and for ducks were 79.37%/80.02% and 75.74%/76.44%, respectively. The iPD/ePR of MCP in broilers and the ePR of MCP in ducks were markedly higher (P < 0.05) than those of DCP. Our data suggest that using the substitution method to evaluate the bioavailability of feed phosphates has its own advantages; MCP has higher biological availability than DCP for broilers and ducks. [ABSTRACT FROM AUTHOR]

A new model characterizing the response of a multi-strand wire rope subjected to axial tension and axial torque is presented in this paper. Apart from most of previous approaches which deal with a straight wire strand, the present model fully considers the double-helix structure in multi-strand configuration. To be further, a new method to compute local deformation parameters (two curvatures and a twist defined by Love, 1944) of each wire is introduced. The proposed model well predicts the global stiffness of the rope. It is found that different friction states between adjacent wires can lead to quite a different distribution of local bending and torsion deformation of double-helix wire. The variations of stresses in double-helix wires along the rope axis are analyzed and the results show that torsion stress of a double-helix wire can be neglected when the rope is subjected to axial tension (axial torsion is restrained). The present model provides a new way to estimate the local deformation and stresses at the wire level, which sheds new insight into the understanding of the fatigue and failure behavior of the wire rope. [ABSTRACT FROM AUTHOR]

Highlights: [•] A micro-sensor is developed to measure the internal temperature of a fuel cell. [•] A 3D CFD analysis is performed to analyze the fuel cell temperature. [•] In-plane temperature distribution is compared with experimental and numerical results. [Copyright &y& Elsevier]

The limited slip systems of magnesium (Mg) and its alloys hamper their widespread applications in key areas. Rational design of such lightweight alloys requires fundamental knowledge of their microscopic plasticity mechanisms which, however, remain partially unresolved. Here, to obtain a better understanding of the plastic deformation mechanisms of Mg alloys, we performed tensile straining over a wide range of strain rates from 10−5 s−1 up to 2000 s−1, revealing for the first time the occurrence of a rate-dependent transition of the dislocation mechanisms. Such a shift of plasticity mechanisms is identified by two distinct activation volumes. Systematic experimental characterizations, such as transmission electron microscopy under two-beam conditions and synchrotron X-ray diffraction analysis, were employed to analyze both qualitatively and quantitatively the characteristics of dislocations at changing strain rates, revealing that the rate-dependent dislocation mechanisms are accompanied by the change of dislocation activities from easy-glide 〈 a 〉 dislocations to glissile 〈 c + a 〉 dislocations with increasing strain rates. Specifically, temporarily glissile 〈 c + a 〉 dislocations, enabled by a thermally activated transformation of dislocation cores from the dissociated configuration to the compact one, govern the plasticity at high strain rates. This is in stark contrast to the dominance of the easy-glide 〈 a 〉 dislocations at low strain rates. Meanwhile, it is found that abundant 〈 c + a 〉 dislocations do not necessarily lead to enhanced ductility, contrary to the common belief. We expect that these results will contribute to a further understanding of the plasticity mechanisms of Mg alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

The materials combining high-entropy alloys with good mechanical properties and magnetic materials with a significant magnetocaloric effect are among the best candidates for magnetic refrigeration. For this purpose, the high-entropy alloys (MnNiSi) 1- x (FeCoGe) x (x = 0.4, 0.42, 0.45, and 0.47) were designed in this study. The effects of the Si/Ge ratio on the magnetocaloric effect and mechanical properties were also investigated. The results show that high-entropy alloy (MnNi) 0.6 Si 0.62 (FeCo) 0.4 Ge 0.38 possesses a Vickers hardness value of 580.6HV2 and compressive strength of 267 MPa with respect to a significant entropy change of 48.5 J·kg−1K−1 under a magnetic field of 5 T near the Curie temperature of 308.8 K. In order to clearly understand the origin of this excellent comprehensive performance, the influence mechanism of crystal structure and configurational entropy were explored. Furthermore, the first-principles calculations indicated that the magnetic properties mainly originate from Mn atoms located in 3 d sites and are influenced by the interaction between the Mn and Fe atoms. Additionally, the total magnetic moment and electron density are taken into account to reveal their influence on magnetocaloric properties. [Display omitted] • An MnNiSi-based magnetocaloric high-entropy alloys with excellent comprehensive properties were obtained. • The MnNiSi-based alloys have good mechanical properties (the Vickers hardness of 580.6 HV2 and compressive strength of 267 MPa). • The magnetocaloric effects of the MnNiSi-based alloys is 48.5 J·kg−1K−1 under 0–5 T at T C = 309 K. • The physical mechanism about good mechanical properties and magnetocaloric effects is revealed from the crystal structure, configurational entropy and electronic structure. [ABSTRACT FROM AUTHOR]

The present work, for the first time, quantitatively studies the evolution of both dislocations and deformation twins with various strain rates in an ATZ311 Mg alloy. Interrupted tensile tests were performed at the strain rates of 0.001, 1 and 600 s−1. Deformation twins were characterized by microscopy techniques and evaluated using the fractions of twin boundaries and twinned area. The average dislocation density and the relative fractions of dislocations with different Burgers vectors were determined from neutron diffraction data. It was found that the twin fraction increases remarkably and becomes saturated at lower strain rates (0.001-1 s−1), while the dislocation density only obtains an obvious enhancement at a much higher strain rate (600 s−1). Besides, the distinctively high flow stress at high strain rate leads to a substantial increase in the density of the hard-to-activate 〈 c + a 〉 -type dislocations, after the 〈 a 〉 -type dislocation density reaches rapidly its saturated value at a small strain level. The twinning modes with opposite polarities are able to coexist in the same grains because of the high local stress concentration at strain rates above 1 s−1. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Objectives Rapid and accurate identification of the causative pathogens of bloodstream infections (BSIs) is crucial for initiating appropriate antimicrobial therapy, which decreases the related morbidity and mortality rates. The aim of this study was to evaluate the usefulness of a newly developed multiplexed, bead-based bioassay system, the Quantamatrix Multiplexed Assay Platform (QMAP) system, obtained directly from blood culture bottles, to simultaneously detect the presence of bacteria and identify the genes for antibiotic resistance. Methods The QMAP system was used to evaluate 619 blood culture bottles from patients with BSIs and to compare the results of conventional culture methods. Results Using conventional bacterial cultures as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of the QMAP system for detection of bacterial pathogens in positive blood culture (PBC) samples were 99.8% ( n = 592, 95% CI 0.9852-1.000, p <0.001), 100% (95% CI 0.983-1.000, p <0.001), 100% (95% CI 0.9922-1.000, p <0.001), and 99.5% (95% CI 0.9695-1.000, p <0.001), respectively. In addition, sensitivity and specificity of the QMAP system for identification of the genes for antibiotic resistance were 99.4% ( n = 158, 95% CI 0.9617-0.9999, p <0.009) and 99.6% (95% CI 0.9763-0.9999, p <0.0001), respectively. Conclusions Obtaining results using the QMAP system takes about 3 hr, while culture methods can take 48–72 hr. Therefore, analysis using the QMAP system is rapid and reliable for characterizing causative pathogens in BSIs. [ABSTRACT FROM AUTHOR]

Due to its explosive, colorless and volatile nature, detection of ethanol is critical in daily life, industrial production and medical treatment. Metal oxide semiconductors (MOS) gas sensors have caught the attention of researchers due to their low cost and convenient detection. Indium oxide (In 2 O 3) is a typical wide band gap n-type semiconductor metal oxide widely used in detecting H 2 S, NO 2 , H 2 , and ethanol. This paper summarizes the strategies used in the last decade to improve the performance of gas sensors based on In 2 O 3 sensitive materials for ethanol detection. These strategies include modifying the morphology of indium oxide sensitive materials, doping and loading, building heterojunctions, and using composite new materials. In addition, the sensing mechanism for ethanol detection by gas sensors is presented. [ABSTRACT FROM AUTHOR]

Large-strain extrusion machining (LSEM) has been emerged as a promising severe plastic deformation methodology for the creation of nano or ultra-fined grained materials. To realize deformation control, the key issue involved is the strain estimation in LSEM. In order to characterize the deformation field in LSEM, the experiments of LSEM oxygen-free high-conductivity copper were conducted by using a specially designed LSEM device. Based upon the deformation field measured by high speed imaging and digital image correlation (DIC), a new strain estimation model considering the extrusion process of constraint is proposed in this paper. The theoretical predicted strain agrees well with the measurements. [ABSTRACT FROM AUTHOR]