Creep Deformation and Rupture in Smooth and Notched Specimens in HK40 Steel

The effects of the eutectic carbides randsecondary carbides on creep deformation andrupture in smooth bars and CT specimens havebeen studied. The results show that the resistanceof the eutectic carbides of skeleton shape tocrack growth is larger than that of the blockyshape carbides. The dendritic segregation ofsecondary carbides promotes the creep ductility.As the secondary carbide particles become coarser,the creep ductility increases and the crackgrowth rate decreases. However, if the sizeof secondary carbide is too large, the creepstrength decreases too much and therefore crackgrowth rate increases.     

Biokinetics of ²¹⁰Po in rats: excretion via urine and faeces and retention in tissues and organs

Daily excretions of 21?Po from rats via urine and faeces following i.v. administration of polonium citrate, from Day 2 to Day 5, were reported, together with retentions in tissues and organs on Day 5. Emphasis is given to the methods of measurement and data quality rather than to the discussion of the observations. The authors aim to contribute data for developing or refining the biokinetic model for 21?Po metabolism.     

Nucleation and Blunting of Nanocracks in Brass

In situ tensile test of brass foil specimens in TEM shows that many dislocations were emitted from a loaded crack tip and a dislocation free zone (DFZ) was formed under condition of constant displacement. The DFZ is an elastic zone, where the stress may equal to the cohesive strength th when the applied stress is high enough. As a result, nanocracks would initiate discontinuously in the DFZ or, sometimes, at a blunted-crack tip. As soon as the nanocrack nucleated, it quickly blunts into a void, which results in ductile fracture.     

Shift and intensity modeling in spectroscopy—general concept and applications

Multivariate analysis and calibration in spectroscopy have been widely used in many fields of applications in recent years. The number of components to use in such applications for sufficiently describing the spectra is dependent on the stability of positions of the peaks of interest. Unwanted shifts give rise to a more complex model, i.e., more components. Various kinds of shift correction can be applied as preprocessing tools to cope with these effects. In this paper we describe a general concept of how to model intensity (peak height) and position as separate phenomena. We described methods and theory from image modeling, and apply them on one-dimensional signals such as traditional Raman spectroscopy.     

Mn and Co substitution in δ-FeOOH and its decomposition products

Cobalt and manganese substituted -FeOOH were obtained and used in the preparation of Fe, Co and Mn, Fe mixed oxides. Cobalt is present in the oxyhydroxide with 2.8–3.0, oxidation states. Lattice parameters and oxidation state decrease with cobalt content. Mn-substituted phases contain manganese in oxidation states decreasing from 4.0 to 3.3 as the degree of substitution is higher. These Mn-oxidation states imply cation vacancies which are alternatively ordered in octahedral sites along the [001] direction of the -oxyhydroxide structure. The thermal decomposition of the cobalt and Mn-substituted samples at 200 ° C leads to mixed oxides with distorted -Fe₂O₃ structure and high manganese and cobalt oxidation states. From 200 to 400 ° C, a reduction process takes place, leading to Mn-substituted sesquioxides, while Co-containing samples decompose into mixtures of spinel and -Fe₂O₃-structure phases.     

Study on Scientific and Sophisticated Equipment Management in Colleges and Universities

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Hydrogen Permeation and Diffusion in Low-carbon Steels and 16Mn Steel

In the present work. the hydrogen permeation and diffusion in two low-carbon steels. # 10 and #20. and 16Mn stee1 over the temperature range of 80 to 330℃ were investigated using gaseous permeation technique. The temperature dependence of hydrogen permeability. diffusivity and solubility for the three steels was obtained in the form of the Arrhenius equations. It was shown that the hydrogen permeability of the 16Mn steel is somewhat lower than that of the two low-carbon steels.whereas the hydrogen diffusivity is lowered in the order of #10, #20 and 16Mn but the activation energy of diffusion is much the same for the three steels. The difference in the diffusivity was attributed to the increase of ferrite-cementite interface areas with the refinement of pearlitic structure in the steels     

The stress dependence of superconducting parameters in pure In and Sn and in α-phase In-Sn alloys

We have measured the length change due to the transition from the super-conducting to the normal state in pure In and Sn and in In-Sn alloys. The measurements were made on single-crystal specimens. The alloys had Sn content ranging from zero to 12 at %. Crystals parallel and perpendicular to the tetragonal axis were grown at each alloy content. We find that the relative length changes l/l are very sensitive to alloy content. From l/l we have calculated the stress derivatives H _c/ and T _c / and we find that T _c / changes from +59 to –92 mK/bar for stress along the tetragonal axis, and from –9 to 46 mK/kbar for stress perpendicular to the tetragonal axis. We suggest that these large changes are due to Fermi surface topology changes upon increasing the Sn content in In.     

Diffusion of carbon and titanium in γ -iron in a magnetic field and a magnetic field gradient

The diffusion coefficients of carbon and titanium in γ -iron were measured in a 6T magnetic field and in magnetic field gradients ranging from 30 to 45 T/m. We have found that the diffusion of carbon in γ -iron is retarded by application of a 6T magnetic field. In contrast with carbon diffusion, no noticeable effect of a magnetic field on the diffusivity of titanium in γ -iron is observed. On the other hand, the diffusion of carbon in γ -iron can be enhanced in a magnetic field gradient when carbon atoms move towards the direction with a higher magnetic field strength. The higher the magnetic field gradient strength becomes, the more the carbon diffusion is enhanced. Nevertheless, a magnetic field gradient causes a decrease in diffusivity of carbon in γ -iron when the opposite magnetic field gradient is applied.     

Polarization and efficiency of a concave multilayer grating in the 135-250-Å region and in normal-incidence and SeyaNamioka mounts

A molybdenum/silicon multilayer coating was applied to a holographic ion-etched blazed grating substrate that had 2400 grooves/mm and a radius of curvature of 2.2 m. Scanning probe microscopy yielded the same surface microroughness (5 ? rms) before and after deposition of the multilayer. The efficiency and polarization performance of the grating was measured by synchrotron radiation in the 135-250-? wavelength region. In the second grating order and the second Bragg order of the multilayer coating, the peak normal-incidence efficiency was 7.5% at a wavelength of 147 ?, representing a groove efficiency of 27%. At an angle of incidence of 35°, the polarization performance of the grating was 95%-100% in the 210-250-? wavelength region. In a Seya-Namioka spectrometer mount at an angle of incidence of 30°-40°, the grating is a nearly perfect polarizing optical element in the wavelength bands between 125 and 300 ?, which are covered by the multilayer coating.     

Preferential reducts and constructs in robust multiple criteria ranking and sorting

We revisit the multiple criteria ranking and sorting methods based on ordinal regression, which accept preference information in the form of, respectively, pairwise comparisons or assignment examples for some reference alternatives. Robust ordinal regression methods consider the whole set of value functions reproducing these holistic statements provided at the input. Its impact on the recommendation is expressed in terms of the necessary and possible preference relations or assignments. We propose methods for generating explanations of this impact, showing pieces of preference information provided by the decision maker (DM), which led to the observed outcomes. In particular, the minimal set of preference information pieces, called preferential reduct, is identified to justify some result observable for the whole set of compatible value functions (e.g., the truth of the necessary relation for some pair of alternatives). Further, the maximal set of preference information pieces, called preferential construct, is discovered to reveal the conditions under which some result non-observable for the whole set of compatible value functions (e.g., the falsity of the possible relation for some pair of alternatives) is possible. Knowing such explanations, the DM can better understand the impact of each piece of preference information on the result and, in consequence, get conviction about the obtained recommendation.     

Ramizol® encapsulation into extended release PLGA micro- and nanoparticle systems for subcutaneous and intramuscular administration: in vitro and in vivo evaluation

Objective: Novel antibiotic Ramizol^® is advancing to clinical trials for the treatment of gastrointestinal Clostridium difficile associated disease. Despite this, previous studies have shown a rapid plasma clearance upon intravenous administration and low oral bioavailability indicating pure drug is unsuitable for systemic infection treatment following oral dosing. The current study aims to investigate the development of poly-lactic-(co-glycolic) acid (PLGA) particles to overcome this limitation and increase the systemic half-life following subcutaneous and intramuscular dosing.

Significance: The development of new antibiotic treatments will help in combatting the rising incidence of antimicrobial resistance.

Methods: Ramizol^® was encapsulated into PLGA nano and microparticles using nanoprecipitation and emulsification solvent evaporation techniques. Formulations were analyzed for particle size, loading level and encapsulation efficiency as well as in vitro drug release profiles. Final formulation was advanced to in vivo pharmacokinetic studies in Sprague–Dawley rats.

Results: Formulation technique showed major influence on particle size and loading levels with optimal loading of 9.4% and encapsulation efficiency of 92.06%, observed using emulsification solvent evaporation. Differences in formulation technique were also linked with subsequent differences in release profiles. Pharmacokinetic studies in Sprague–Dawley rats confirmed extended absorption and enhanced bioavailability following subcutaneous and intramuscular dosing with up to an 8-fold increase in T_max and T_1/2 when compared to the oral and IV routes.

Conclusions: Subcutaneous and intramuscular dosing of PLGA particles successfully increased systemic half-life and bioavailability of Ramizol^®. This formulation will allow further development of Ramizol^® for systemic infection eradication.     

Tannic acid incorporation in chitosan-based microparticles and in vitro controlled release

Chitosan, a natural polycationic polysaccharide, was coupled with two polyanionic polymers: Na-alginate and carboxymethylcellulose (CMC) and with tannic acid (TA) obtaining three species of self-assembled complexes: chitosan/alginate/TA (sample 1), chitosan/TA (sample 2) and chitosan/CMC/TA (sample 3). The microparticle formation was achieved by dropwise addition of one solution into other by using a coaxial airflow sprayer. These systems were characterized with regard to particle size distribution, thermal stability, tannic acid entrapment efficiency. Sample 2 showed quite a different behavior compared to the other two samples; the particle diameter is located in the nanometric region, the quantity of incorporated tannic acid is higher than in the other two samples and the material shows better thermal stability. The release of tannic acid from these complexes was studied in water (pH = 5.89), phosphates buffer (pH = 7.04) and acetate buffer (pH = 4.11). These studies revealed two distinct periods in tannic acid delivery process: an initial period, varying between 4 and 10 h, characterized by a high release rate with a delivered tannic acid amount of approximately 80% of the incorporated polyphenol and a second period, which starts after 20 to 30 h of delivery and it ends after approximately 120 h, when the release process takes place with low and constant rate and the kinetic curve is linear—characteristic for a zero order kinetic.     

Nucleation and Formation of Stable and Metastable Phases in Undercooled AI-Li Melts

A modified nucleation and competitive growth kinetic theory considering unsteady nucleation andeffect of composition in dilute binary alloys was suggested,based on which the selections of δ.δ'and α phases in undercooled Al-Li melts were summarized by both isothermal and continuous cool-ing treatment methods.     

An Investigation into Large and Precise Instrument Management in Colleges and Universities

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Research of BIM Technology in Urban Rail Operation and Maintenance and Application

With the rapid development of urban rail transit, the traditional operation and maintenance methods mainly rely on manpower, and the pressure on equipment operation and maintenance is increasing, and the low work efficiency, high intensity and high operating costs have always been the main problems at this stage. Through BIM visualization technology can effectively solve those problems, the operation and maintenance mode of urban rail signal equipment at this stage is discussed, the integration ...     

Analyzing fault and severity in pedestrian–motor vehicle accidents in China

The number of pedestrian–motor vehicle accidents and pedestrian deaths in China surged in recent years. However, a large scale empirical research on pedestrian traffic crashes in China is lacking. In this study, we identify significant risk factors associated with fault and severity in pedestrian–motor vehicle accidents. Risk factors in several different dimensions, including pedestrian, driver, vehicle, road and environmental factors, are considered. We analyze 6967 pedestrian traffic accident reports for the period 2006–2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report. Pedestrian traffic crashes have a unique inevitability and particular high risk, due to pedestrians’ fragility, slow movement and lack of lighting equipment. The empirical analysis of the present study has the following policy implications. First, traffic crashes in which pedestrians are at fault are more likely to cause serious injuries or death, suggesting that relevant agencies should pay attention to measures that prevent pedestrians from violating traffic rules. Second, both the attention to elderly pedestrians, male and experienced drivers, the penalty to drunk driving, speeding, driving without a driver's license and other violation behaviors should be strengthened. Third, vehicle safety inspections and safety training sessions for truck drivers should be reinforced. Fourth, improving the road conditions and road lighting at night are important measures in reducing the probability of accident casualties. Fifth, specific road safety campaigns in rural areas, and education programs especially for young children and teens should be developed and promoted. Moreover, we reveal a country-specific factor, hukou, which has significant effect on the severity in pedestrian accidents due to the discrepancy in the level of social insurance/security, suggesting that equal social security level among urban and rural people should be set up. In addition, establishing a comprehensive liability distribution system for non-urban areas and roadways will be conducive to both pedestrians’ and drivers’ voluntary compliance with traffic rules.