Synthesis of crystalline and amorphous, particle-agglomerated 3-D nanostructures of Al and Si oxides by femtosecond laser and the prediction of these particle sizes

We report a single step technique of synthesizing particle-agglomerated, amorphous 3-D nanostructures of Al and Si oxides on powder-fused aluminosilicate ceramic plates and a simple novel method of wafer-foil ablation to fabricate crystalline nanostructures of Al and Si oxides at ambient conditions. We also propose a particle size prediction mechanism to regulate the size of vapor-condensed agglomerated nanoparticles in these structures. Size characterization studies performed on the agglomerated nanoparticles of fabricated 3-D structures showed that the size distributions vary with the fluence-to-threshold ratio. The variation in laser parameters leads to varying plume temperature, pressure, amount of supersaturation, nucleation rate, and the growth rate of particles in the plume. The novel wafer-foil ablation technique could promote the possibilities of fabricating oxide nanostructures with varying Al/Si ratio, and the crystallinity of these structures enhances possible applications. The fabricated nanostructures of Al and Si oxides could have great potentials to be used in the fabrication of low power-consuming complementary metal-oxide-semiconductor circuits and in Mn catalysts to enhance the efficiency of oxidation on ethylbenzene to acetophenone in the super-critical carbon dioxide.

Synthesis of crystalline and amorphous, particle-agglomerated 3-D nanostructures of Al and Si oxides by femtosecond laser and the prediction of these particle sizes

We report a single step technique of synthesizing particle-agglomerated, amorphous 3-D nanostructures of Al and Si oxides on powder-fused aluminosilicate ceramic plates and a simple novel method of wafer-foil ablation to fabricate crystalline nanostructures of Al and Si oxides at ambient conditions. We also propose a particle size prediction mechanism to regulate the size of vapor-condensed agglomerated nanoparticles in these structures. Size characterization studies performed on the agglomerated nanoparticles of fabricated 3-D structures showed that the size distributions vary with the fluence-to-threshold ratio. The variation in laser parameters leads to varying plume temperature, pressure, amount of supersaturation, nucleation rate, and the growth rate of particles in the plume. The novel wafer-foil ablation technique could promote the possibilities of fabricating oxide nanostructures with varying Al/Si ratio, and the crystallinity of these structures enhances possible applications. The fabricated nanostructures of Al and Si oxides could have great potentials to be used in the fabrication of low power-consuming complementary metal-oxide-semiconductor circuits and in Mn catalysts to enhance the efficiency of oxidation on ethylbenzene to acetophenone in the super-critical carbon dioxide.

Complex Impedance Spectroscopic Studies of PMMA(80,70,60,50) : PC(10,20,30,40): PVP(10): LiClO4(5) Polymer Solid Electrolyte Systems

Polymer solid electrolytes PMMA(80,70,60,50): PC(10,20,30,40):PVP(10):LiClO4(5) were synthesized according to stoichiometric ratios using solution cast method. FTIR study confirms the good complexation among the constituent materials in the polymers matrix. Complex impedance and electric modulus studies are carried out and explained. From cole-cole plots, maximum decrement of resistance is observed at a threshold ratio 70Wt% PMMA: 20Wt% PC: 10Wt% PVP: 5Wt% LiClO4 and this could be due to the high mobility of the Li+ ion in the polymer network due to the plasticizer. The plasticizer plays an important role in decreasing the viscosity of the system, which in turn favors the mobility of segmental motion of polymer network and fast ion motion in the polymer. Real and Imaginary electric modulus spectra show the presence of relaxation peaks and confirm that the polymer solid electrolyte is an ionic conductor.

BLOOD PRESSURE TO HEIGHT RATIO AS A SCREENING TOOL FOR HYPERTENSION IN SCHOOL GOING ADOLESCENTS AGED 12-18 YEARS IN BHAVNAGAR, GUJARAT

Background: The age, gender, and height, percentiles requirements for the ‘gold-standard’ diagnosis of hypertension and prehypertension in adolescents make it time-consuming for clinicians and difficult-to-use by non-professionals. Simplified diagnostic tools are therefore needed. The use of blood pressure-to-height ratio (BPHR), systolic (SBPHR) and diastolic (DBPHR), has been reported in Han adolescents, and it requires validation in other racial groups. The diagnostic accuracy of SBPHR and DBPHR in Bhavnagar, Gujarat, India was therefore studied. Methods: From a population of 1000 school going Caucasian adolescents aged 12-18 years from two schools; Blood pressures were measured using standard procedures. Hypertension and prehypertension (HTPHT) were defined according to the 2004 Working Group normative tables. ROC curve analyses were used to assess the diagnostic accuracy of BPHR in defining HTPHT in this population. Sex-specific threshold values for SBPHR and DBPHR were determined and thereafter used to define HTPHT. The sensitivity/specificity of this method was determined. Results: The accuracy of SBPHR and DBPHR in diagnosing HTPHT, in both sexes, was >92%. The optimal threshold ratio for prehypertension was 0.725/0.465 in boys and 0.745/0.465 in girls; while for hypertension, they were 0.765/0.495 in boys and 0.795/0.515 in girls. The sensitivity and specificity of this method was >88%. Conclusions: The use of blood pressure-to-height ratio BPHR is valid, simple, and accurate in this population. Keywords: Adolescents; Blood pressure-to-height ratio; Diagnosis; Prehypertension; Hypertension; Bhavnagar; School

COMPARATIVE ANALYSIS OF STEEL CORROSION RESISTANCE

The objective of the study was to conduct the comparative analysis of steel types corrosion resistance. Three selected steel types were used in the study. The selected types were structural steel, stainless steel, and MMFX steel. The methodology we adopted is that we evaluated the steel parts resistance towards corrosion by doing in-salt spray experiment and the immersion of aqueous solution of sodium chloride. For salt spray test, we used guidelines by ASTM B117. This practice provides a controlled corrosion environment which is used for exposing specimen to salt spray chamber. For immersion test, test specimens are analyzed at regular time interval as the first rust is appeared. For carbon steel, we used three specimen and mostly initial rust appeared in initial 13 to 15 hours. For stainless steel, inter granular corrosion were analyzed. The results show that the first cycle started after about 46 hours; the second cycle started about 1% and the third cycle started with the rage of about 2 to 30%. For MMFX 2 steel, the results show that for MMFX carbon steel, the chloride threshold ratio is about 6 times higher than black bars and more than double of other types. The conclusion of the study is that in big structures like bridges, the MMFX steel should be used.

Differential Susceptibility of Xylella fastidiosa Strains to Synthetic Bactericidal Peptides

The kinetics of cell inactivation and the susceptibility of Xylella fastidiosa subspecies fastidiosa, multiplex, and pauca to synthetic antimicrobial peptides from two libraries (CECMEL11 and CYCLO10) were studied. The bactericidal effect was dependent on the relative concentrations of peptide and bacterial cells, and was influenced by the diluent, either buffer or sap. The most bactericidal and lytic peptide was BP178, an enlarged derivative of the amphipathic cationic linear undecapeptide BP100. The maximum reduction in survivors after BP178 treatment occurred within the first 10 to 20 min of contact and at micromolar concentrations (<10 μM), resulting in pore formation in cell membranes, abundant production of outer membrane vesicles, and lysis. A threshold ratio of 109 molecules of peptide per bacterial cell was estimated to be necessary to initiate cell inactivation. There was a differential susceptibility to BP178 among strains, with DD1 being the most resistant and CFBP 8173 the most susceptible. Moreover, strains showed a proportion of cells under the viable but nonculturable state, which was highly variable among strains. These findings may have implications for managing the diseases caused by X. fastidiosa.

Molybdate to prevent the formation of sulfide during the process of biogas production

The process of anaerobic digestion producing biogas is an eco-friendly energy source that promotes recycling from waste biomass such as food chain residues, wet waste, wastewater. In this study, we focused on the problem of the sulfide (H2S) produced by the sulfate-reducing bacteria (SRB) in the presence of sulfate residues. This byproduct is dangerous for human health and an issue due to the highly corrosive effect on metallic components. To this purpose, the Molybdate, a sulfate analog, known in the literature to inhibit SRBs by blocking the first enzyme of the metabolic pathway of anaerobic respiration, was applied. The experiments carried out showed that a concentration of 0.3 mM of molybdate was enough to inhibit the SRB in a complex environment of the anaerobically digested sludge (ADS) took from a real biogas producing bioreactor. During the study, we observed the importance of the sulfate concentration sulfate in the system. Indeed, the production of sulfide was stopped only under the threshold ratio value of 1:10 (molybdate: sulfate). In the short term, the addition of molybdate did not alter the production and quality (% of methane) of the biogas, nor the anaerobic microbial community, including SRB population itself.

Preferential activation of small cutaneous fibers through small pin electrode also depends on the shape of a long duration electrical current

Background Electrical stimulation is widely used in experimental pain research but it lacks selectivity towards small nociceptive fibers. When using standard surface patch electrodes and rectangular pulses, large fibers are activated at a lower threshold than small fibers. Pin electrodes have been designed for overcoming this problem by providing a higher current density in the upper epidermis where the small nociceptive fibers mainly terminate. At perception threshold level, pin electrode stimuli are rather selectively activating small nerve fibers and are perceived as painful, but for high current intensity, which is usually needed to evoke sufficient pain levels, large fibers are likely co-activated. Long duration current has been shown to elevate the threshold of large fibers by the mechanism of accommodation. However, it remains unclear whether the mechanism of accommodation in large fibers can be utilized to activate small fibers even more selectively by combining pin electrode stimulation with a long duration pulse. Results In this study, perception thresholds were determined for a patch- and a pin electrode for different pulse shapes of long duration. The perception threshold ratio between the two different electrodes was calculated to estimate the ability of the pulse shapes to preferentially activate small fibers. The perception threshold ratios were compared between stimulation pulses of 5- and 50 ms durations and shapes of: exponential increase, linear increase, bounded exponential, and rectangular. Qualitative pain perception was evaluated for all pulse shapes delivered at 10 times perception threshold. The results showed a higher perception threshold ratio for long duration 50 ms pulses than for 5 ms pulses. The highest perception threshold ratio was found for the 50 ms, bounded exponential pulse shape. Results furthermore revealed different strength-duration relation between the bounded exponential- and rectangular pulse shapes. Pin electrode stimulation at high intensity was mainly described as “stabbing”, “shooting”, and “sharp”. Conclusion These results indicate that long duration pulses with a bounded exponential increase preferentially activate the small nociceptive fibers with a pin electrode and concurrently cause elevated threshold of large non-nociceptive fibers with patch electrodes.

On Strength Adjustment for MCTS-Based Programs

This paper proposes an approach to strength adjustment for MCTS-based game-playing programs. In this approach, we use a softmax policy with a strength index z to choose moves. Most importantly, we filter low quality moves by excluding those that have a lower simulation count than a pre-defined threshold ratio of the maximum simulation count. We perform a theoretical analysis, reaching the result that the adjusted policy is guaranteed to choose moves exceeding a lower bound in strength by using a threshold ratio. The approach is applied to the Go program ELF OpenGo. The experiment results show that z is highly correlated to the empirical strength; namely, given a threshold ratio 0.1, z is linearly related to the Elo rating with regression error 47.95 Elo where −2≤z ≤2. Meanwhile, the covered strength range is about 800 Elo ratings in the interval of z in [−2,2]. With the ease of strength adjustment using z, we present two methods to adjust strength and predict opponents’ strengths dynamically. To our knowledge, this result is state-of-the-art in terms of the range of strengths in Elo rating while maintaining a controllable relationship between the strength and a strength index.