Technology development of titanium dioxide photocatalytic water-splitting for hydrogen production

简单介绍了二氧化钛光催化分解水制氢的基本原理。综述了加入牺牲剂、碳酸钠、贵金属负载化、金属离子掺杂、阴离子掺杂、染料光敏化、半导体复合以及离子注入等提高二氧化钛光催化制氢的方法,讨论了这几种改性技术的机理以及对提高二氧化钛在可见光下的制氢效率的作用。重点讨论了阴离子掺杂和离子注入技术的机理和研究进展,指出离子注入是目前扩展二氧化钛光响应的最为有效的技术。最后讨论了光催化分解水制氢的氢氧分离问题,并通过与其他制氢技术的对比分析,指出光催化制氢将是通往氢经济的非常有潜力的制氢技术。The basic mechanism of titanium dioxide photocatalytic water-splitting for hydrogen production is introduced. The methods to enhance hydrogen production are reviewed, including addition of sacrificial reagent, addition of sodium carbonate, noble metal loading, metal ion doping, anion doping, dye sensitization, semiconductor composition and ion implantation. The mechanism of photocatalyst modification methods and their effects on hydrogen production are discussed. Emphasis is particularly given to anion doping and metal ion-implantation. It can be seen that metal ion-implantation is presently the most effective method to expand light response of titanium dioxide into visible region. The practical consideration oxygen and hydrogen gas separation, is also addressed. Compared with other hydrogen production technologies, photocatalytic water-splitting hydrogen production is a promising technology toward hydrogen economy.published_or_final_versio

Antimicrobial Activity of Mushrooms against Skin Infection Causing Pathogens

Mushrooms are nutritionally functional food and a source of physiologically beneficial and nontoxic medicines for various diseased conditions. In the present study antimicrobial properties of crude extracts of three commercial edible mushrooms (Agaricus bisporus (J.E.Lange) Imbach , Pleurotus florida (Mont.) and Calocybe indica (P&A) were tested against bacteria and fungi that cause local dermatitis by disc diffusion method. Highest anti-microbial activity was obtained from petroleum ether extract of Agaricus bisporus, with the zone of inhibition 17mm (Streptococus pyogenes), 15mm (Staphylococus aureus), 14mm (Pseudomonas aeuroginosa) and 13mm (Candida albicans) from 100µg/ml concentration of mushroom extracts respectively, while minimal zone was obtained from the petroleum ether extract of Pleurotus florida and very least inhibition was observed in Calocybe indica. From the results it is inferred that crude extracts of commercially available mushrooms namely Agaricus bisporus and Pleurotus florida can be used to treat pathogenic microbes that cause skin irritations, bristles and acnes. This study gives scope for the investigations on active constituents of mushrooms for better understanding of the healing mechanism

Durability study on ambient cured geopolymer concrete made with various molarities of NaOH

Geopolimerni beton inovativna je varijacija konvencionalnog građevnog materijala koja smanjuje utjecaj proizvodnje običnog portlandskog cementa (OPC) na okoliš, a istovremeno poboljšava učinkovitu primjenu industrijskih nusproizvoda. Promjenom molariteta natrijevog hidroksida na 4M, 6M, 8M, 10M i 12M, za ovo je istraživanje pripremljeno pet kombinacija geopolimernog betona. Nakon 28 dana njegovanja na sobnoj temperaturi, procijenjena su svojstva čvrstoće, tj. tlačna čvrstoća (DT i NDT), vlačna čvrstoća cijepanjem i čvrstoća na savijanje. Potom su ispitana i svojstva trajnosti kao što su početno upijanje vode, upijanje vode do zasićenja, sorptivnost, prosječna efektivna poroznost, otpornost na habanje i otpornost na kemijsko djelovanje. Rezultati istraživanja geopolimernog betona uspoređeni su s rezultatima istraživanja betona OPC razreda M35. Rezultati eksperimentalnog ispitivanja pokazali su da, s iznimkom GPC-4M, ostale geopolimerne mješavine betona zadovoljavaju zahtjeve ciljane čvrstoće betona razreda M35. Rezultati istraživanja otkrili su da su se GPC-8M betonski uzorci pokazali kao najbolji u smislu svojstva čvrstoće i trajnosti. Stoga se umjesto OPC betona preporučuje raširenija uporaba geopolimernog betona, koji se priprema s letećim pepelom i mljevenom granuliranom zgurom iz visokih peći te njeguje na temperaturi okoline.Geopolymer concrete is an innovative variation of the conventional construction material that reduces the environmental impact of producing Ordinary Portland Cement (OPC) while simultaneously improving the efficient use of industrial by-products. By altering the molarities of sodium hydroxide to 4M, 6M, 8M, 10M, and 12M, five combinations of geopolymer concrete were prepared for this study. After 28 days of curing at room temperature, the strength properties, viz., the compressive strength (DT and NDT), the splitting tensile strength, and the flexural strength were evaluated. Additionally, the durability properties such as the initial water absorption, saturated water absorption, sorptivity, average effective porosity, abrasion resistance, and chemical attack resistance were studied as well. All the findings of the geopolymer concrete were compared to those of the M35 grade OPC concrete. The experimental test results showed that, with the exception of GPC-4M, the other Geopolymer concrete mixtures met the target strength requirements of the M35 grade concrete. The findings revealed that the GPC-8M concrete specimens performed the best in terms of strength and durability. Consequently, widespread use of geopolymer concrete, which is prepared with fly ash (FA) and ground granulated blast-furnace slag and cured in ambient air, is recommended instead of OPC concrete

Cloning and characterization of the Plasmodium falciparum adenylosuccinate synthetase gene

The cloning and deduced amino acid sequence of Plasmodium falciparum adenylosuccinate synthetase (PfADSS) are reported. PfADSS exhibited 67% homology with the human enzyme. On expression in Escherichia coli, enzymatically active ADSS was produced as deduced by functional complementation analysis. The PfADSS activity was inhibited by hadacidin, a known competitive inhibitor of this enzyme. Nucleotide sequence data are available at GenBank under accession number AF095282

Qualitative study of riccati difference equation on maneuvering target tracking and fault diagnosis of wind turbine gearbox

Various performance analyses using Interacting Multiple Model (IMM) algorithm for the stability of tracking a maneuvering target are dealt with the state error covariance. A noble way of analyzing the stability of the IMM algorithm for a linear systems with the upper and lower bounds of the error covariance is analyzed. For this persuasion, a two-model Interacting Multiple Model Kalman Filter (IMMKF) with constant acceleration and constant jerk model has been applied for two different case studies. One is tracking a maneuvering target, and the another is tracking a vibration of wind turbine gearbox, which helps to identify failure component in wind energy system. The required data are collected from a radar and a defected gear box of a test wind turbine, and the efficiency of IMM algorithm is analyzed by simulation experiments

Association of ultra-processed food intake with risk of inflammatory bowel disease: Prospective cohort study

Objective: To evaluate the relation between intake of ultra-processed food and risk of inflammatory bowel disease (IBD).Design: Prospective cohort study.Setting: 21 low, middle, and high income countries across seven geographical regions (Europe and North America, South America, Africa, Middle East, south Asia, South East Asia, and China).Participants: 116 087 adults aged 35-70 years with at least one cycle of follow-up and complete baseline food frequency questionnaire (FFQ) data (country specific validated FFQs were used to document baseline dietary intake). Participants were followed prospectively at least every three years.Main outcome measures: The main outcome was development of IBD, including Crohn\u27s disease or ulcerative colitis. Associations between ultra-processed food intake and risk of IBD were assessed using Cox proportional hazard multivariable models. Results are presented as hazard ratios with 95% confidence intervals.Results: Participants were enrolled in the study between 2003 and 2016. During the median follow-up of 9.7 years (interquartile range 8.9-11.2 years), 467 participants developed incident IBD (90 with Crohn\u27s disease and 377 with ulcerative colitis). After adjustment for potential confounding factors, higher intake of ultra-processed food was associated with a higher risk of incident IBD (hazard ratio 1.82, 95% confidence interval 1.22 to 2.72 for ≥5 servings/day and 1.67, 1.18 to 2.37 for 1-4 servings/day compared with \u3c1 serving/day, P=0.006 for trend). Different subgroups of ultra-processed food, including soft drinks, refined sweetened foods, salty snacks, and processed meat, each were associated with higher hazard ratios for IBD. Results were consistent for Crohn\u27s disease and ulcerative colitis with low heterogeneity. Intakes of white meat, red meat, dairy, starch, and fruit, vegetables, and legumes were not associated with incident IBD.Conclusions: Higher intake of ultra-processed food was positively associated with risk of IBD. Further studies are needed to identify the contributory factors within ultra-processed foods.Study registration: ClinicalTrials.gov NCT03225586

Variations in incidence of venous thromboembolism in low-, middle-, and high-income countries

AimsTo examine the rates of venous thromboembolism (VTE) in high-income, upper middle-income, and lower middle/low-income countries (World Bank Classification).Methods and ResultsWe examined the rates of VTE in high-income, upper middle-income, and lower middle/low-income countries (World Bank Classification) in a cohort derived from four prospective international studies (PURE, HOPE-3, ORIGIN, and COMPASS). The primary outcome was a composite of pulmonary embolism, deep vein thrombosis, and thrombophlebitis. We calculated age- and sex-standardized incidence rates (per 1000 person-years) and used a Cox frailty model adjusted for covariates to examine associations between the incidence of VTE and country income level. A total of 215 307 individuals (1.5 million person-years of follow-up) from high-income (n = 60 403), upper middle-income (n = 42 066), and lower middle/low-income (n = 112 838) countries were included. The age- and sex-standardized incidence rates of VTE per 1000 person-years in high-, upper middle-, and lower middle/low-income countries were 0.87, 0.25, and 0.06, respectively. After adjusting for age, body mass index (BMI), smoking, antiplatelet therapy, anticoagulant therapy, education level, ethnicity, and incident cancer diagnosis or hospitalization, individuals from high-income and upper middle-income countries had a significantly higher risk of VTE than those from lower middle/low-income countries [hazard ratio (HR) 3.57, 95% confidence interval (CI) 2.40-5.30 and HR 2.27, 95% CI 1.59-3.23, respectively]. The effect of country income level on VTE risk was markedly stronger in people with a lower BMI, hypertension, diabetes, non-White ethnicity, and higher education.ConclusionThe rates of VTE are substantially higher in high-income than in low-income countries. The factors underlying the increased VTE risk in higher-income countries remain unknown.</div

Multifactorial Correlates of Blood Pressure in South Asian Children in Canada: A Cross-Sectional Study

Objective&nbsp;We sought to explore various correlates of blood pressure (BP) and hypertension, and to identify the most important aggregate combination of correlates for BP in South Asian children. Design&nbsp;Cross-sectional study Setting&nbsp;Community-based recruitment in two Canadian cities Participants&nbsp;South Asian children (n=762) provided a range of physiological, lifestyle and social variables. BP was assessed using an automated device. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and BP were transformed to z-scores using published standards. Outcome measures&nbsp;Linear and logistic regression analyses were used to explore associations between the range of variables with BP z-scores and hypertension while stepwise regression was used to identify aggregate factors that provided explanatory capacity for systolic BP (SBP) and diastolic BP (DBP) z-scores. Results&nbsp;A range of variables were associated with BP z-score and hypertension in unadjusted analysis. On adjustment for confounders, the association between age (β=−0.054, 95%&thinsp;CI=−0.078 to 0.029), female sex (β=−0.208, 95% CI=−0.350 to –0.067), height (β=0.022, 95% CI=0.011 to 0.033), weight (β=0.047, 95% CI=0.040 to 0.055), BMI z-score (β=0.292, 95%&thinsp;CI=0.249 to 0.336), WC z-score (β=0.273, 95% CI=0.219 to 0.326), WHtR z-score (β=0.289, 95% CI=0.236 to 0.342), heart rate (β=0.016, 95% CI=0.010 to 0.022), child’s perception of body image (β=0.183, 95% CI=0.128 to 0.239) and grip strength (β=0.025, 95% CI=0.007 to 0.043) with SBP z-score remained. In stepwise regression, age, sex, BMI z-score, heart rate and weight accounted for 30% of the variance of SBP z-score, while age, BMI z-score, heart rate and daily fast food intake accounted for 23% of the DBP z-score variance. Conclusion&nbsp;Our findings suggest that variables, such as age, sex, height, adiposity and heart rate, provide stronger explanatory capacity to BP variance and hypertension risk than other variables in South Asian children