ELECTROCHEMICAL IMPEDANCE AND DIGITAL IMAGE METHODS TO DETECT INITIAL DEPOSITION OF MICROORGANISMS

Microorganism in industrial cooling water can cause corrosion and biofouling. Electrochemical impedance method and digital image method (DIM) were used to detect quantitatively iron bacteria and heterotrophic bacteria. Microorganism growth and metabolism can change the impedance of culture medium. The detection time of impedance variation lie in the function relationship with the logarithm of bacteria concentration. 7-million-pixel CCD sensor was used to shoot the shape of microorganism in order to count the number. Compared with most probable number (MPN) method, the detection time of electrochemical impedance is shortened. The DIM reduces the bacteria counting time and the inaccuracy associated with human count

Predicting the location of weld line in microinjection-molded polyethylene via molecular orientation distribution

YesThe microstructure and molecular orientation distribution over both the length and the thickness of microinjection‐molded linear low‐density polyethylene with a weld line were characterized as a function of processing parameters using small‐angle X‐ray scattering and wide‐angle X‐ray diffraction techniques. The weld line was introduced via recombination of two separated melt streams with an angle of 180° to each other in injection molding. The lamellar structure was found to be related to the mold temperature strongly but the injection velocity and the melt temperature slightly. Furthermore, the distributions of molecular orientation at different molding conditions and different positions in the cross section of molded samples were derived from Hermans equation. The degree of orientation of polymeric chains and the thickness of oriented layers decrease considerably with an increase of both mold temperature and melt temperature, which could be explained by the stress relaxation of sheared chains and the reduced melt viscosity, respectively. The level of molecular orientation was found to be lowest in the weld line when varying injection velocity, mold temperature, and melt temperature, thus providing an effective means to identify the position of weld line induced by flow obstacles during injection‐molding process.Jilin Scientific and Technological Development Program. Grant Number: 20180519001JH; National Key R&D Program of China. Grant Number: 2018YFB0704200; National Natural Science Foundation of China. Grant Numbers: 21674119, 21790342; Newton Advanced Fellowship of Royal Society. Grant Number: NA15022

Continuous twin screw rheo-extrusion of an AZ91D magnesium alloy

© The Minerals, Metals & Materials Society and ASM International 2012The twin screw rheo-extrusion (TSRE) is designed to take advantage of the nondendritc microstructure and thixotropic characterization of semisolid-metal slurries and produce simple metal profiles directly from melts. The extrusion equipment consists of a rotor-stator high shear slurry maker, a twin screw extruder, and a die assembly. The process is continuous and has a potential for significantly saving energy, manufacturing cost, and enhancing efficiency. The present investigation was carried out to study the process performance for processing rods of an AZ91D magnesium alloy and the microstructure evolution during processing. The semisolid slurry prepared by the process was characterized by uniformly distributed nondendritic granular primary phase particles. AZ91D rods with uniform and fine microstructures and moderate mechanical properties were produced. For the given slurry making parameters, decreasing extrusion temperature was found to improve microstructures and properties. The mechanisms of particle granulation and refinement and the effect of processing parameters on process performance and thermal management are discussed. © 2012 The Minerals, Metals & Materials Society and ASM International.EPSRC (UK) and Rautomead Lt

Resonant Interaction Between a Weak Gravitational Wave and a Microwave Beam in the Double Polarized States Through a Static Magnetic Field

We investigate the resonant interaction to the weak gravitational waves in a coupling electromagnetic system, which consists of a Gaussian beam with the double polarized transverse electric modes, a static magnetic field and the fractal membranes. We find that under the syncroresonance condition a high-frequency GW (HFGW) of h=10^-30,v_g=3GHz may produce the perturbative photon flux (PPF) of 2.15*10/s in a surface of 0.01m^2. The PPF can be pumped out from the background photon fluxes and one might obtain the amplified signal photon flux of 2.15*10^4s^-1 by cascade fractal membranes. It appears to be worthwhile to study this effect for the detection of the high-frequency relic GWs in quintessential inflationary models and the HFGWs expected by possible laboratory schemes.Comment: 10page

Tensile Deformation of Oriented Poly(ε-caprolactone) and Its Miscible Blends with Poly(vinyl methyl ether)

The structural evolution of micromolded poly(ε-caprolactone) (PCL) and its miscible blends with noncrystallizable poly(vinyl methyl ether) (PVME) at the nanoscale was investigated as a function of deformation ratio and blend composition using in situ synchrotron smallangle X-ray scattering (SAXS) and scanning SAXS techniques. It was found that the deformation mechanism of the oriented samples shows a general scheme for the process of tensile deformation: crystal block slips within the lamellae occur at small deformations followed by a stressinduced fragmentation and recrystallization process along the drawing direction at a critical strain where the average thickness of the crystalline lamellae remains essentially constant during stretching. The value of the critical strain depends on the amount of the amorphous component incorporated in the blends, which could be traced back to the lower modulus of the entangled amorphous phase and, therefore, the reduced network stress acting on the crystallites upon addition of PVME. When stretching beyond the critical strain the slippage of the fibrils (stacks of newly formed lamellae) past each other takes place resulting in a relaxation of stretched interlamellar amorphous chains. Because of deformation-induced introduction of the amorphous PVME into the interfibrillar regions in the highly oriented blends, the interactions between fibrils becomes stronger upon further deformation and thus impeding sliding of the fibrils to some extent leading finally to less contraction of the interlamellar amorphous layers compared to the pure PCLNational Natural Science Foundation of China (21204088 and 21134006). This work is within the framework of the RCUK/EPSRC Science Bridges China project of UK−China Advanced Materials Research Institute (AMRI)

All-cause mortality and risk factors in a cohort of retired military male veterans, Xi'an, China: an 18-year follow up study

<p>Abstract</p> <p>Background</p> <p>Risk factors of all-cause mortality have not been reported in Chinese retired military veterans. The objective of the study was to examine the risk factors and proportional mortality in a Chinese retired military male cohort.</p> <p>Methods</p> <p>A total of 1268 retired military men aged 55 or older were examined physically and interviewed using a standard questionnaire in 1987. The cohort was followed up every two years and the study censored date was June30, 2005 with a follow-up of up to 18 years. Death certificates were obtained from hospitals and verified by two senior doctors. Data were entered (double entry) by Foxbase, and analysis was carried out by SAS for Windows 8.2. Multivariate Cox proportional hazard regression model was used to compute hazard ratio (HR) and 95% confidence interval (CI).</p> <p>Results</p> <p>The total person-years of follow-up was 18766.28. Of the initial cohort of 1268 men, 491 had died, 748 were alive and 29 were lost to follow up. Adjusted mortality (adjusted for age, blood pressure, body mass index, cholesterol, triglycerides, alcohol, exercise, and existing disease) was 2,616 per 100,000 person years. The proportional mortality of cancer, vascular disease and Chronic Obstructive Pulmonary Disease (COPD) were 39.71%, 28.10% and 16.90% respectively. Multivariate analysis showed that age, cigarettes per day, systolic blood pressure, triglyceride, family history of diseases (hypertension, stroke and cancer), existing diseases (stroke, diabetes and cancer), body mass index, and age of starting smoking were associated with all-cause mortality, HR (95%CI) was1.083(1.062–1.104), 1.026(1.013–1.039), 1.009(1.003–1.015), 1.002(1.001–1.003), 1.330(1.005–1.759), 1.330(1.005–1.759), 1.444(1.103–1.890), 2.237(1.244–4.022), 1.462(1.042–2.051), 2.079(1.051–4.115), 0.963(0.931–0.996)and 0.988(0.978–0.999)respectively. Compared with never-smokers, current smokers had increased risks of total mortality [HR 1.369(1.083–1.731)], CHD [HR 1.805 (1.022–3.188)], and lung cancer [HR 2.939 (1.311–6.585)].</p> <p>Conclusion</p> <p>The three leading causes of diseases were cancer, CHD and stroke, and COPD. Aging, cigarette smoking, high systolic blood pressure, high triglyceride, family history of cancer, hypertension and stroke, existing cases recovering from stroke, diabetes and cancer, underweight, younger age of smoking were risk factors for all-cause mortality. Quitting cigarette smoking, maintaining normal blood pressure, triglyceride and weight are effect control strategies to prevent premature mortality in this military cohort.</p

Grain refinement of magnesium alloys: a review of recent research, theoretical developments and their application

This paper builds on the ‘‘Grain Refinement of Mg Alloys’’ published in 2005 and reviews the grain refinement research onMg alloys that has been undertaken since then with an emphasis on the theoretical and analytical methods that have been developed. Consideration of recent research results and current theoretical knowledge has highlighted two important factors that affect an alloy’s as-cast grain size. The first factor applies to commercial Mg-Al alloys where it is concluded that impurity and minor elements such as Fe and Mn have a substantially negative impact on grain size because, in combination with Al, intermetallic phases can be formed that tend to poison the more potent native or deliberately added nucleant particles present in the melt. This factor appears to explain the contradictory experimental outcomes reported in the literature and suggests that the search for a more potent and reliable grain refining technology may need to take a different approach. The second factor applies to all alloys and is related to the role of constitutional supercooling which, on the one hand, promotes grain nucleation and, on the other hand, forms a nucleation-free zone preventing further nucleation within this zone, consequently limiting the grain refinement achievable, particularly in low solute-containing alloys. Strategies to reduce the negative impact of these two factors are discussed. Further, the Interdependence model has been shown to apply to a broad range of casting methods from slow cooling gravity die casting to fast cooling high pressure die casting and dynamic methods such as ultrasonic treatment