Deleterious Gas Research Articles

Pt|Cu Bimetallic Stratiform Nanocrystal Cluster Hierarchical Frameworks: Robust Catalyst for Hydrolyzing Ammonia Borane to Generate Hydrogen

AbstractA modified Galvani substitution protocol is proposed to fabricate serial Pt|Cu nanocrystals for hydrolyzing ammonia borane to generate H2 gas. The as‐fabricated Pt|Cu spheroidal nanocrystals with mean size of 75 nm hold porously hierarchical waxberry‐shaped appearance, with more subtle Pt grain cladding on Cu nanospheres to build the nanocrystal cluster frameworks. The lower Pt/Cu molar ratios result in the formation of a razor‐thin sublayer of Pt‐Cu alloy at the bimetallic interface; for the higher Pt/Cu molar ratios, no alloy phase forms, also without formation of probable oxides. The synergic effect contributes to the electron enrichment around Pt, helping to furnish more active sites. The catalytic ability increases with rising of Pt/Cu molar ratios; the Pt|Cu‐0.75 unfolds the abnormality even overtopping Pt NPs, with a turnover frequency value of 78.36 mol (H2)·min–1·(mol Pt)–1 and apparent activation energy of 32.89 kJ·mol–1. The catalytic hydrolytic reaction at the lower temperatures (298, 303 K) is identified as a first‐order reaction, while it belongs to second‐order reaction under the higher temperatures (308, 313, 318 K). The Pt|Cu‐0.75 nanocrystals express satisfactory stability with only 14% loss of the catalytic activity after 5‐time services, and excellent catalytic selectivity with no deleterious gas detected.

Interactions Between Strontium and Sodium Fluorosilicate in the Combined Treatment of A319 Al Alloy

The mechanical properties of cast aluminum–silicon alloys are typically improved by eutectic silicon modification and melt degassing. First, trace strontium additions can modify the silicon phase and relieve stress concentrations at the naturally coarse, acicular particles. Second, chemical degasser additions, such as sodium fluorosilicate, can remove dissolved hydrogen gas from the aluminum melt to prevent the formation of deleterious gas porosity. However, combining both treatments is difficult, due to the tendency of the two chemicals to react and reduce their effectiveness. Nonetheless, there is limited research outlining specific procedures to enable their maximum potency, with both additions. In this work, the effects of strontium and sodium fluorosilicate on the eutectic silicon morphology and casting porosity in A319 aluminum alloy were investigated. This included a comprehensive study of the fading of their individual additions as well as the influence of separating the two chemical additions by various time intervals. The results of the melt treatments were characterized using optical microscopy, density measurements, and analysis of strontium contents using optical emission spectrometry. It was found that the maximum potency of both treatments was achieved by degassing prior to strontium additions, featuring both satisfactory silicon modification and porosity reductions.

RF Controlled Metal and Deleterious Gas Detecting Rover

Many advance technologies have undergone for the space missions and also geographical locations in space. Earlier humans had to move manually to space for the research but it was risky and resulting in loss of life. Hence in present and the future technology everything is operated and controlled through robots, this device deals with the rover which can move anywhere in the space surface. This rover is built with ARM controller interfaced with Gas and Metal detector sensor. This Rover also contains Zigbee module to transmit the result obtained to the receiver section and it displays the result on LCD. It is operated through RF controlled remote for making the checkpoint as per the user commands.

Research on Fire Disaster Fire-Fighting Simulation System of Large-Long Tunnel

The large-long highway tunnel provides advantaged condition for highway traffic, at the same time, it also become bottleneck and accident point of the highway. Relative to the highway outside the tunnel, tunnel inside belongs to semi-closed environment and the drive condition is relatively poor, it makes tunnel become velocity bottleneck. Because of uncirculated air in tunnel and all kinds of deleterious gas let by vehicle, it is easy to result into traffic jam and secondary disaster. Large-long tunnel system is a complicated system integrated with many-sided theory and technology, such as traffic, detection and environment, and so on. The traffic flow in tunnel has unrepeatable characteristic. By building traffic flow model, fire disaster and environment model in the paper, the fire-fighting response mechanism, the action process and the realization technology in the condition of fire disaster are researched in emphases. It provided use for reference for the engineering building of Large-Long tunnel, the layout and design of fire-fighting establishment inside tunnel and the running management mechanism of tunnel.

Radiation Cured Epoxy Acrylate Composites Based on Graphene, Graphite Oxide and Functionalized Graphite Oxide with Enhanced Properties

Epoxy acrylate (EA) composites containing graphite oxide (GO), graphene and nitrogen-double bond functionalized graphite oxide (FGO) were fabricated using UV-radiation and electron beam radiation via in-situ polymerization. Graphene and FGO were homogenously dispersed in EA matrix and enhanced properties, including thermal stability, flame retardancy, electrical conductivity and reduced deleterious gas releasing in thermo decomposition were obtained. Microscale combustion colorimeter results illustrated improved flame retardancy; EA/FGO composites achieved a 29.7% reduction in total heat release (THR) when containing only 0.1% FGO and a 38.6% reduction in peak-heat release rate (PHRR) when containing 3% FGO. The onset decomposition temperatures were delayed and the maximum decomposition values were reduced, according to thermogravimetric analysis which indicated enhanced thermal stabilities. The electrical conductivity was increased by 6 orders of magnitude (3% graphene) and the deleterious gas released during the thermo decomposition was reduced with the addition of all the graphite samples. This study represented a new approach to functionalize GO with flame retardant elements and active curable double bond to achieve better dispersion of GO into polymer matrix to obtain nanocomposites and paved a way for achieving graphene-based materials with high-performance of graphene in enhancement of flame retardancy of polymers for practical applications.

Study on H2S Monitoring Technique for High Risk Wellsite

Abstract During petroleum exploitation, deleterious gases, such as hydrogen sulphide, often present at wellsites, leading to dangers like creature death and explosion. Wellsite H2S can come from several ways with different diffuse concentration respectively, and the most practical defending method is rational monitoring and emergency measures. Aiming at the wellsite safety when exploiting reservoirs with high pressure, high temperature and high H2S component, studies are made in three steps. Firstly, the sources, possible overflow points and overflow quantity of H2S are summarized according to field steps including well testing, workover and production. The concept of alarmweight for H2S concentration is proposed and weight values corresponding to different alarm level are proposed. Secondly, H2S leakage and diffusion are modeled by commercial software, with wellsite equipment, wind and gas leaking rate considered. Thirdly, position and number of monitors are recommended according to operation procedure, and emergency measures are proposed in response to industry standards and field experience. Parts of the results have been used in wellsite deleterious gas defense in eight wells in Yuanba district, Sichuan province.

Prevention and Origin of Exceptional Deleterious Gas Compositions in Coal Mine

The abnormal content of gas compositions of H2S, CO2, CO and N2 under coal mine has close relationship of safe production and comprehensive utilization of coal gas. According to original analyses of anomalous accumulation characteristics of the above-mentioned gas in China, the paper suggests that abnormal thermochemistry effect, osmosis effect of surface water, sealed effect of coalseam floor, coal types and coal metamorphose degree are the main factors which contribute to abnormity of deleterious gas compositions. Based on study of gas origin, primary measures for prevention and control of deleterious gas in coal excavating course were brought forward. The research has guiding significance for safe production of coal mine.

船倉タンク内で二酸化炭素中毒により溺死した作業者の剖検例

A 49-year-old male captain fell and unfortunately died in a hold tank where he had entered to rescue his fainting co-worker on the disposing waste fluid left there. An autopsy revealed that the captain died from drowning in the waste fluid. In order to clarify the cause of their falling in the tank, the gas in the hold tank was analyzed. The concentration of oxygen was 18.86 to 19.31%, carbon dioxide was 7.28 to 9.07% and the other gases, including hydrogen sulfide, were assessed to be under the normal level. It was concluded that the intoxication of carbon dioxide generated from the waste fluid fermentation was the cause of this fatal accident through loss of consciousness. It is necessary to recognize that carbon dioxide is a dangerous and deleterious gas in circumstances where the gas can be produced.

The Analysis on the Effect of Hyperbaric Oxygen Treatment in Deleterious Gas Poisoning

目的 探讨高压氧(HBO)在治疗二氧化硫、烟雾(混合气体)、一氧化碳等急性有害气体中毒的时效对患者预后的影响.方法 根据42例有害气体中毒患者人院时间不同分为3组.A组:吸入有毒气体2～4 h入院;B组:吸入有毒气体24 h入院;C组:吸入有毒气体48 h人院.对3组不同时间入院(患者入院时间是根据中毒症状出现早晚)的有害气体中毒患者应用HBO治疗效果进行对比分析.结果 2～4 h入院患者经及时HBO治疗效果明显好于24 h和48 h入院采用HBO治疗的患者,而且减少了并发症的出现,改善了预后,提高了治愈率.经χ2检验,治疗效果显效以上A组与C组χ2=30,P＜0.01,B组与C组χ2=11.25,P＜0.01有显著性差异.治疗效果好转以上A组与C组χ2=8.57,P＜0.01,B组与C组χ2=4.50,P＜0.05有显著性差异.表明HBO早期治疗(24 h内)有害气体中毒疗效显著.结论 对急性有害气体中毒的治疗,除积极进行对症支持疗法外,应早期应用HBO治疗。

Gas Exchange Response to Short-Acting β2-Agonists in Chronic Obstructive Pulmonary Disease Severe Exacerbations

Short-acting beta(2)-agonists are one of the mainstays of bronchodilator strategy for exacerbations of chronic obstructive pulmonary disease (COPD). The assessment of pulmonary gas exchange after salbutamol in COPD severe exacerbations remains unknown. We investigated whether the effects of nebulized salbutamol during COPD severe exacerbations are associated with further deterioration of pulmonary gas exchange. We examined patients with severe COPD when hospitalized for exacerbation (n = 9), and while in stable convalescence. We assessed spirometry, arterial blood gases, systemic hemodynamics, and V/Q relationships 30 and 90 minutes after administration of 5.0 mg salbutamol. At exacerbation, compared with baseline, 30 minutes after salbutamol administration, cardiac output (Q) increased (from 6.5 +/- [SEM] 0.4 to 7.3 +/- 0.5 L . min(-1)) (p < 0.03) alone, without inducing changes in gas exchange indices. When in convalescence, compared with baseline, 30 minutes after salbutamol, there was an increase in Q (from 5.7 +/- 0.5 to 7.0 +/- 0.6 L . min(-1)) and Vo(2) (from 211 +/- 12 to 232 +/- 11 ml . min(-1)) (p < 0.002 each), whereas Pa(O(2)) decreased (from 71 +/- 4 to 63 +/- 3 mm Hg) and alveolar-arterial Po(2) difference increased due to increased perfusion of low-V/Q-ratio regions (from 4.5 +/- 2.6 to 9.6 +/- 4.1% of Q) (p < 0.05); Sa(O(2)) (93 +/- 2%) and Pa(CO(2)) (43 +/- 2 mm Hg) remained unchanged. This deleterious gas exchange response persisted at 90 minutes. At exacerbation, salbutamol does not aggravate pulmonary gas exchange abnormalities. When in convalescence, however, baseline lung function improvement was associated with a detrimental gas exchange response to salbutamol, resulting in further V/Q imbalance and small decreases in Pa(O(2)) compounded by small increases in Q and Vo(2).

MOVPE growth of InP using isobutylphosphine and tert-butylphosphine

Two organophosphorus compounds, isobutylphosphine and tertiarybutylphosphine, have been investigated for their possible use as precursors in the metalorganic vapor phase epitaxy (MOVPE) process. They are the first organometallic compounds to be used as phosphorus sources. Pyrolysis studies show that the first decomposition products are phosphine and various organic compounds. The phosphine then pyrolyzes to give phosphorus. The materials are less pyrophoric and less toxic than phosphine. Since they are used as liquids in atmospheric pressure bubblers, they are much safer to use. The compounds have been used to grow epitaxial layers of InP on InP and GaAs substrates using trimethylindium in a flowing hydrogen ambient. No evidence of deleterious gas phase reaction is observed. The optimum temperature for growth using IBP is approximately 630°C. This yields excellent morphology layers with the strongest photoluminescence intensity and narrowest half-width, both of which are comparable to InP grown using PH 3. Carbon incorporation is nearly identical using IBP and PH 3. The IBP and TBP are not quite as pure as the best PH 3. The lowest carrier concentration measured was in the low 10 16 cm −3 range with room temperature mobilities as high as 2800 cm 2/V·s for TBP. Using TBP slightly higher mobilities of 3100 cm 2/V· were obtained.