Morphology and Orientation Selection of Non-Metallic Inclusions in Electrified Molten Metal

The effect of electric current on morphology and orientation selection of non-metallic inclusions in molten metal has been investigated using theoretical modelling and numerical calculation. Two geometric factors, namely the circularity (fc) and alignment ratio (fe) were introduced to describe the inclusions shape and configuration. Electric current free energy was calculated and the values were used to determine the thermodynamic preference between different microstructures. Electric current promotes the development of inclusion along the current direction by either expatiating directional growth or enhancing directional agglomeration. Reconfiguration of the inclusions to reduce the system electric resistance drives the phenomena. The morphology and orientation selection follows the routine to reduce electric free energy. The numerical results are in agreement with our experimental observations

Creating a scale for assessing socially sustainable tourism

As destinations absorb even increasing number of visitors, destination managers become progressively more concerned about the longer term viability of tourism from a resident’s perspective. However, few studies have examined the application of real time social sustainability within tourism, particularly how to measure impacts on social sustainability. This study outlines the development of a valid and reliable scale – the Scale of Social Sustainability (SSS) - for tourism that provides an assessment of social sustainability in destination settings. A 10-step procedure was developed drawing upon the related literature. A telephone poll-based survey generated 1,839 valid responses from Hong Kong residents. Hong Kong’s growing popularity as a destination provides a rich array of host–guest conflict situations. Dimensionality was identified using exploratory and confirmatory factor analyses. Construct validity, reliability, and stability were assessed, and found good, showing that the scale could be used by other destinations worldwide. The theoretical and managerial implications of the scale are discussed, including options for annual surveys giving policy makers alerts before situations worsen. Detailed host resident viewpoints, and the large scale of the survey can help local residents be informed about tourism development and better involved in the policy formation process

Does Tourist–Host Social Contact Reduce Perceived Cultural Distance?

Tourist–host social contact significantly influences the perceptions of tourists and deserves more attention from scholars in the field of tourism research. However, studies on the relationship between these two constructs are limited. To address this research gap, the present study develops and validates instruments for measuring social contact and perceived cultural distance in the context of tourism, explores the effects of social contact on perceived cultural distance, and provides implications for tourism stakeholders, including governments, tourism operators, and local communities. A survey was conducted among Hong Kong tourists traveling to Mainland China. The study had two significant findings: (1) the quality of contact negatively influences tourists’ perceived cultural distance and (2) in terms of the quantity of contact, social-oriented contacts negatively influence perceived cultural distance, whereas service-oriented contacts positively affect perceived cultural distance. Implications were provided to contribute to theoretical and empirical realms, and to guide policy formulation

Domain movement in rabbit muscle adenylate kinase might involve proline isomerization

AbstractThe fluorescence probe, 8-anilino-1-naphthalenesulfonic acid (ANS), was used to monitor the induced-fit conformational movement in rabbit muscle adenylate kinase. In 50 mM Tris-HCl buffer (pH 8.1), the time course of ANS binding to rabbit muscle adenylate kinase is a biphasic process. The fast phase completes within the dead-time of the stopped-flow equipment used (about 15 ms), while the slow phase ends in about 10 minutes. In the presence of 2.0 μM peptidyl prolyl cis/trans-isomerase, the rate constant of the slow phase reaction is accelerated about 2.4-fold, suggesting that the domain movement during ANS binding to rabbit muscle adenylate kinase may involve proline isomerization. The activation energy of the slow phase was determined to be 74.6 kJ/mol, which is comparable to the activation energy of proline cis/trans-isomerization (about 80 kJ/mol)

Interaction Between Hot Carrier Aging and PBTI Degradation in nMOSFETs: Characterization, Modelling and Lifetime Prediction

Modelling of the interaction between Hot Carrier Aging (HCA) and Positive Bias Temperature Instability (PBTI) has been considered as one of the main challenges in nanoscale CMOS circuit design. Previous works were mainly based on separate HCA and PBTI instead of Interacted HCA-PBTI Degradation (IHPD). The key advance of this work is to develop a methodology that enables accurate modelling of IHPD through understanding the charging/discharging and generation kinetics of different types of defects during the interaction between HCA and PBTI. It is found that degradation during alternating HCA and PBTI stress cannot be modelled by independent HCI/PBTI. Different stress sequence, i.e. HCA-PBTI-HCA and PBTI-HCA-PBTI, lead to completely different degradation kinetics. Based on the Cyclic Anti-neutralization Model (CAM), for the first time, IHPD has been accurately modelled for both short and long channel devices. Complex degradation mechanisms and kinetics can be well explained by our model. Our results show that device lifetime can be underestimated by one decade without considering interaction

Black phosphorus integrated tilted fiber grating for ultrasensitive heavy metal sensing

We propose an integrated black phosphorus (BP)-tilted fiber grating (TFG) configuration as an enhanced light-matter interaction platform for heavy metal chemical sensing. We synthesized BP nanosheets by using a liquid-phase exfoliation method and developed an in-situ layer-by-layer (i-LbL) technique for BP nanosheets deposition. These approaches secured high-quality BP coating on specific fiber cylindrical surface with strong adhesion as well as a prospective thickness control. By taking advantage of i-LbL deposition, the unique optical tunable features including coating thickness-dependent polarization and polarization- selective coupling have been experimentally observed. Furthermore, the BP-TFG was exploited as the first BP-fiber optic chemical sensor for heavy metal Pb2+ ions detection, demonstrating significant performance of ultrahigh sensitivity up to 0.5 × 10−3 dB/ppb, much lower limit of detection down to 0.25 ppb, and extremely wide concentration range from 0.1 ppb to 1.5 × 107 ppb. We believe that this BP-fiber optic architecture opens the path as an optical platform for superior chemical sensing and biomedical applications

Manipulation of magnetization reversal of Ni81Fe19 nanoellipse arrays by tuning the shape anisotropy and the magnetostatic interactions

Two series of highly ordered two-dimensional arrays of Ni81Fe19 nanoellipses were nanofabaricated with different aspect ratios, R, and element separations, S, to investigate the influence of the self-demagnetization and the magnetostatic interaction upon the magnetization reversal. For nanostructures with low shape anisotropy, an additional magnetic easy axis was induced orthogonal to the shape-induced easy axis by reducing the separations along both axes. For the structures with larger shape anisotropy, the switching field distribution/coercivity (SFD/Hc ) was reduced, and for the array with the smallest separations (20 nm and 35 nm along the long and short axes, respectively), coherent rotation of the whole array occurred. The magnitude of both the shape anisotropy and a configurational anisotropy induced by the magnetostatic interactions have been estimated. These results provide some useful information for the design of potential magnetic nanodot logic and for high-density magnetic random access memory

Effects of yeast culture on broiler growth performance, nutrient digestibility and caecal microbiota

This study was conducted to evaluate the effects of yeast culture (YC) supplementation on the growth performance, apparent nutrient digestibility and caecal microflora of broiler chickens. A total of 360 one-day-old Arbor Acres broiler chickens were randomly assigned to six dietary treatments containing 0.2%, 0.4%, 0.6%, 0.8% and 1% YC. The experiment lasted for 42 days. Diet and faecal samples were collected for analysis of dry matter, crude protein, ether extract, calcium and phosphorus. Caecal microbiota on days 21 and 42 were measured using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR. Dietary supplementation with YC did not affect feed intake. On day 42, the 0.8% YC group showed optimal growth and feed efficiency, as well as higher levels of apparent digestibility of ether extract, calcium and phosphorus. On day 21, both 0.8% and 1% YC groups exhibited a significant increase in Ruminococcus, Propionibacterium clostridiales, and Bifidobacterium density. The density of Bacteroides in the YC groups was significantly higher than that of the control group. On day 42, the densities of Bacteroides, Sphingomonas and Bifidobacterium were higher in the 0.8% YC group, whereas a significant decrease was observed in the number of Enterobacteriaceae. These results serve as evidence that dietary supplementation with 0.8% YC not only moderately optimized the feed efficiency and the apparent digestibility of ether extract, calcium and phosphorus, but also positively influenced the caecal bacterial density and diversity in broiler chickens.Keywords: Arbor Acres broiler, caecal microflora, yeast culture supplementatio