The Interesting Influence of Nanosprings on the Viscoelasticity of Elastomeric Polymer Materials: Simulation and Experiment

Among all carbon nanostructured materials, helical nanosprings or nanocoils have attracted particular interest as a result of their special mechanical behavior. Here, carbon nanosprings are used to adjust the viscoelasticity and reduce the resulting hysteresis loss (HL) of elastomeric polymer materials. Two types of nanospring‐filled elastomer composites are constructed as follows: system I is obtained by directly blending polymer chains with nanosprings; system II is composed of the self‐assembly of a tri‐block structure such as chain‐nanospring‐chain. Coarse‐grained molecular dynamics simulations show that the incorporation of nanosprings can improve the mechanical strength of the elastomer matrix through nanoreinforcement and considerably decrease the hysteresis loss. This finding is significant for reducing fuel consumption and improving fuel efficiency in the automobile tire industry. Furthermore, it is revealed that the spring constant of nanosprings and the interfacial chemical coupling between chains and nanosprings both play crucial roles in adjusting the viscoelasticity of elastomers. It is inferred that elastomer/carbon nanostructured materials with good flexibility and reversible mechanical response (carbon nanosprings, nanocoils, nanorings, and thin graphene sheets) have both excellent mechanical and low HL properties; this may open a new avenue for fabrication of high performance automobile tires and facilitate the large‐scale industrial application of these materials. Carbon nanosprings are found to have the capability to tune the mechanical and viscoelastic properties of elastomeric polymer materials. It is inferred that elastomer/carbon nanostructured materials with good flexibility and reversible mechanical response (i.e., carbon nanosprings, nanocoils, nanorings, and thin graphene sheets) have both excellent mechanical properties and low hysteresis loss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96669/1/adfm_201201438_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96669/2/1156_ftp.pd

Managing migrant worker's job satisfaction: A study on a manufacturing company in Malaysia

The purpose of this study is to examine and gain a better understanding of the impact of human resource practices on migrant workers' job satisfaction in a manufacturing company. Ninety migrant workers consist of 52 Bangladeshi and 38 Nepalese workers participated in this study. Data was obtained using questionnaires and analyzed. Statistical analysis using regression analysis found the research model has a weak predictive power on migrant workers' job satisfaction. Among the independent variables, only compensation was found to have an impact on migrant workers job satisfaction. T-test results also revealed that Nepalese workers and migrant workers who possess only primary education have higher job satisfaction

Ultrahigh-temperature microwave annealing of Al⁺- and P⁺-implanted 4H-SiC

In this work, an ultrafast solid-state microwaveannealing has been performed, in the temperature range of 1700–2120°C on Al⁺- and P⁺-implanted 4H-SiC. The solid-state microwave system used in this study is capable of raising the SiC sample temperatures to extremely high values, at heating rates of ∼600°C∕s. The samples were annealed for 5–60s in a pure nitrogen ambient. Atomic force microscopy performed on the annealed samples indicated a smooth surface with a rms roughness of 1.4nm for 5×5μm² scans even for microwaveannealing at 2050°C for 30s. Auger sputter profiling revealed a <7nm thick surface layer composed primarily of silicon, oxygen, and nitrogen for the samples annealed in N₂, at annealing temperatures up to 2100°C. X-ray photoelectron spectroscopy revealed that this surface layer is mainly composed of silicon oxide and silicon nitride. Secondary ion mass spectrometry depth profiling confirmed almost no dopant in diffusion after microwaveannealing at 2100°C for 15s. However, a sublimation of ∼100nm of the surface SiC layer was observed for 15sannealing at 2100°C. Rutherford backscattering spectra revealed a lattice damage-free SiC material after microwaveannealing at 2050°C for 15s, with scattering yields near the virgin SiC material. Van der Pauw–Hall measurements have revealed sheet resistance values as low as 2.4kΩ∕□ for Al⁺-implanted material annealed at 2100°C for 15s and 14Ω∕□ for the P+-implanted material annealed at 1950°C for 30s. The highest electron and hole mobilities measured in this work were 100 and 6.8cm2/Vs, respectively, for the P⁺- and Al⁺-implanted materials.The GMU work is supported by Army Research Of- fice Dr. Prater under Grant No. W911NF-04-1-0428 and a subcontract from LT Technologies under NSF SBIR Grant No. 0539321

Genome-Wide Identification and Functional Analysis of NADPH Oxidase Family Genes in Wheat During Development and Environmental Stress Responses

As the key producers of reactive oxygen species (ROS), NADPH oxidases (NOXs), also known as respiratory burst oxidase homologs (RBOHs), play crucial roles in various biological processes in plants with considerable evolutionary selection and functional diversity in the entire terrestrial plant kingdom. However, only limited resources are available on the phylogenesis and functions of this gene family in wheat. Here, a total of 46 NOX family genes were identified in the wheat genome, and these NOXs could be classified into three subgroups: typical TaNOXs, TaNOX-likes, and ferric reduction oxidases (TaFROs). Phylogenetic analysis indicated that the typical TaNOXs might originate from TaFROs during evolution, and the TaFROs located on Chr 2 might be the most ancient forms of TaNOXs. TaNOXs are highly expressed in wheat with distinct tissue or organ-specificity and stress-inducible diversity. A large-scale expression and/or coexpression analysis demonstrated that TaNOXs can be divided into four functional groups with different expression patterns under a broad range of environmental stresses. Different TaNOXs are coexpressed with different sets of other genes, which widely participate in several important intracellular processes such as cell wall biosynthesis, defence response, and signal transduction, suggesting their vital but diversity of roles in plant growth regulation and stress responses of wheat

Prescribing patterns of low doses of antipsychotic medications in older Asian patients with schizophrenia, 2001-2009

Background: This study examined the use of low doses of antipsychotic medications (300mg/day CPZeq or less) in older Asian patients with schizophrenia and its demographic and clinical correlates. Methods: Information on hospitalized patients with schizophrenia, aged 55 years or older, was extracted from the database of the Research on Asian Psychotropic Prescription Patterns (REAP) study (2001-2009). Data on 1,452 patients in eight Asian countries and territories including China, Hong Kong, Japan, Korea, Singapore, Taiwan, India, and Malaysia were analyzed. Sociodemographic and clinical characteristics and antipsychotic prescriptions were recorded using a standardized protocol and data collection procedure. Results: The prescription frequency for low doses of antipsychotic medications was 40.9% in the pooled sample. Multiple logistic regression analysis of the whole sample showed that patients on low doses of antipsychotic medications were more likely to be female, have an older age, a shorter length of illness, and less positive symptoms. Of patients in the six countries and territories that participated in all the surveys between 2001 and 2009, those in Japan were less likely to receive low doses of antipsychotics. Conclusion: Low doses of antipsychotic medications were only applied in less than half of older Asian patients with schizophreni

Fabrication of CuO nanoparticle interlinked microsphere cages by solution method

Here we report a very simple method to convert conventional CuO powders to nanoparticle interlinked microsphere cages by solution method. CuO is dissolved into aqueous ammonia, and the solution is diluted by alcohol and dip coating onto a glass substrate. Drying at 80 °C, the nanostructures with bunchy nanoparticles of Cu(OH)2can be formed. After the substrate immerges into the solution and we vaporize the solution, hollow microspheres can be formed onto the substrate. There are three phases in the as-prepared samples, monoclinic tenorite CuO, orthorhombic Cu(OH)2, and monoclinic carbonatodiamminecopper(II) (Cu(NH3)2CO3). After annealing at 150 °C, the products convert to CuO completely. At annealing temperature above 350 °C, the hollow microspheres became nanoparticle interlinked cages

Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0

We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data samples at both resonances collected with the BES III detector in 2009. We measure the corresponding branching fractions with unprecedented precision and provide mass spectra and Dalitz plots. The branching fraction for J/psi -> pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.) +0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4. The J/psi decay is found to be dominated by an intermediate rho(770) state, whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2, leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure