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

Pasture BMP effectiveness using an HRU-based subarea approach in SWAT

Citation: Aleksey Y. Sheshukov, Kyle R. Douglas-Mankin, Sumathy Sinnathamby, Prasad Daggupati, Pasture BMP effectiveness using an HRU-based subarea approach in SWAT, Journal of Environmental Management, Volume 166, 2016, Pages 276-284, ISSN 0301-4797, http://dx.doi.org/10.1016/j.jenvman.2015.10.023.Many conservation programs have been established to motivate producers to adopt best management practices (BMP) to minimize pasture runoff and nutrient loads, but a process is needed to assess BMP effectiveness to help target implementation efforts. A study was conducted to develop and demonstrate a method to evaluate water-quality impacts and the effectiveness of two widely used BMPs on a livestock pasture: off-stream watering site and stream fencing. The Soil and Water Assessment Tool (SWAT) model was built for the Pottawatomie Creek Watershed in eastern Kansas, independently calibrated at the watershed outlet for streamflow and at a pasture site for nutrients and sediment runoff, and also employed to simulate pollutant loads in a synthetic pasture. The pasture was divided into several subareas including stream, riparian zone, and two grazing zones. Five scenarios applied to both a synthetic pasture and a whole watershed were simulated to assess various combinations of widely used pasture BMPs: (1) baseline conditions with an open stream access, (2) an off-stream watering site installed in individual subareas in the pasture, and (3) stream or riparian zone fencing with an off-stream watering site. Results indicated that pollutant loads increase with increasing stocking rates whereas off-stream watering site and/or stream fencing reduce time cattle spend in the stream and nutrient loads. These two BMPs lowered organic P and N loads by more than 59% and nitrate loads by 19%, but TSS and sediment-attached P loads remained practically unchanged. An effectiveness index (EI) quantified impacts from the various combinations of off-stream watering sites and fencing in all scenarios. Stream bank contribution to pollutant loads was not accounted in the methodology due to limitations of the SWAT model, but can be incorporated in the approach if an amount of bank soil loss is known for various stocking rates. The proposed methodology provides an adaptable framework for pasture BMP assessment and was utilized to represent a consistent, defensible process to quantify the effectiveness of BMP proposals in a BMP auction in eastern Kansas

Dietary Patterns and the Risk of Acute Myocardial Infarction in 52 Countries Results of the INTERHEART Study

Background: Diet is a major modifiable risk factor for cardiovascular disease, but it varies markedly in different regions of the world. The objectives of the present study were to assess the association between dietary patterns and acute myocardial infarction (AMI) globally. Methods and Results: INTERHEART is a standardized case-control study involving participants from 52 countries. The present analysis included 5761 cases and 10 646 control subjects. We identified 3 major dietary patterns using factor analysis: Oriental (high intake of tofu and soy and other sauces), Western (high in fried foods, salty snacks, eggs, and meat), and prudent (high in fruit and vegetables). We observed an inverse association between the prudent pattern and AMI, with higher levels being protective. Compared with the first quartile, the adjusted ORs were 0.78 (95% CI 0.69 to 0.88) for the second quartile, 0.66 (95% CI 0.59 to 0.75) for the third, and 0.70 (95% CI 0.61 to 0.80) for the fourth (P for tren

Availability, aff ordability, and consumption of fruits and vegetables in 18 countries across income levels: fi ndings from the Prospective Urban Rural Epidemiology (PURE) study

Background Several international guidelines recommend the consumption of two servings of fruits and three servings of vegetables per day, but their intake is thought to be low worldwide. We aimed to determine the extent to which such low intake is related to availability and aff ordability. Methods We assessed fruit and vegetable consumption using data from country-specifi c, validated semi-quantitative food frequency questionnaires in the Prospective Urban Rural Epidemiology (PURE) study, which enrolled participants from communities in 18 countries between Jan 1, 2003, and Dec 31, 2013. We documented household income data from participants in these communities; we also recorded the diversity and non-sale prices of fruits and vegetables from grocery stores and market places between Jan 1, 2009, and Dec 31, 2013. We determined the cost of fruits and vegetables relative to income per household member. Linear random eff ects models, adjusting for the clustering of households within communities, were used to assess mean fruit and vegetable intake by their relative cost. Findings Of 143 305 participants who reported plausible energy intake in the food frequency questionnaire, mean fruit and vegetable intake was 3·76 servings (95% CI 3·66–3·86) per day. Mean daily consumption was 2·14 servings (1·93–2·36) in low-income countries (LICs), 3·17 servings (2·99–3·35) in lower-middle-income countries (LMICs), 4·31 servings (4·09–4·53) in upper-middle-income countries (UMICs), and 5·42 servings (5·13–5·71) in highincome countries (HICs). In 130 402 participants who had household income data available, the cost of two servings of fruits and three servings of vegetables per day per individual accounted for 51·97% (95% CI 46·06–57·88) of household income in LICs, 18·10% (14·53–21·68) in LMICs, 15·87% (11·51–20·23) in UMICs, and 1·85% (–3·90 to 7·59) in HICs (ptrend=0·0001). In all regions, a higher percentage of income to meet the guidelines was required in rural areas than in urban areas (p<0·0001 for each pairwise comparison). Fruit and vegetable consumption among individuals decreased as the relative cost increased (ptrend=0·00040). Interpretation The consumption of fruit and vegetables is low worldwide, particularly in LICs, and this is associated with low aff ordability. Policies worldwide should enhance the availability and aff ordability of fruits and vegetables

Maritime Security Governance: Indonesia, Malaysia, and Singapore’s Approach Towards the Proliferation Security Initiative

Maritime security governance of a strategic strait is a unique exercise that presents formidable complexity for States bordering the strait. These waterways often have choke points the proper management of which is critical for the safe passage of commercial and military vessels. The focus of this article is on the Straits of Malacca (SOM) as a strategic maritime passage that is subject to multiple interests involving governance, military, and commercial aspects. This article seeks to examine maritime security governance approaches by Indonesia, Malaysia, and Singapore towards the Proliferation Security Initiative (PSI). The littoral States bordering the SOM bear the responsibility to provide sufficient security measures to international shipping. But littoral States have certain limitations such as insufficient assets, enforcement, and clear governance frameworks in dealing with multifaceted, multi-layered, and multiple nations and actors’ involvement and interest in the SOM. Hence, Indonesia, Malaysia, and Singapore want to cooperate with user States and other non-State entities, however, there are certain caveats to this willingness. Their reservations clearly manifest in maritime security initiatives such as the PSI. The purpose of this article is to explain why the three littoral states adopt diverging approaches towards the PSI, determine why they agree to cooperate with certain initiatives but not others, and understand how the PSI is related to institutional arrangements available in this region

Cyanobacteria from the Baltic Sea and Finnish lakes as an energy source and modulators of bioenergetic pathways

Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).Siirretty Doriast

In Vitro And In Vivo Studies Of Cassia Surattensis Flower Against Aspergillus Niger

Infectious disease is one of the commonest health problems in developing countries with the rise of antibiotic resistance. Invasive aspergillosis is causing high mortality and morbidity rate among immunosuppressed patients. Therefore, there is an urgent need for novel antifungal therapy to control the fatality rate in the population. Opting on medicinal plants has become the current trend amongst scientific investigators as plants are rich with biological activities. Cassia surattensis flower was studied to identify this organ as a potential antifungal agent. Screening of selected pathogenic microorganisms which were inclusive of Gram positive bacteria, Bacillus subtilis, Bacillus thuringiensis, Micrococcus sp and Staphylococcus aureus, Gram negative bacteria, Escherichia coli, Proteus mirabilis and Salmonella sp and fungi Candida albicans, Aspergillus niger and Rhizopus sp against the flower extract revealed this flower to possess antimicrobial properties. The zone of inhibition for microorganisms from disc diffusion assay ranged from 13 ± 0.04 mm to 18 ± 0.00 mm. Microorganisms that were weak against the flower extract were further evaluated with Minimum Inhibitory Concentration (MIC) assay to determine the flower extract activity against the microorganisms in a dose dependent manner. MIC values for both Gram positive and Gram negative bacteria ranged from 3.125 mg/mL to 25.00 mg/mL. For fungi, the MIC value ranged from 3.125 mg/mL to 6.25 mg/mL. The presence of antifungal agent in the flower extract caused damage to the hyphae and conidiophores of A. nige