Application of TRIZ creativity intensification approach to chemical process safety

This study develops a modified method of TRIZ to improve safety in chemical process design. This method is modified by the theory of TRIZ, which is inventive problem solving theory, for retrofit design of chemical process considering safety.The original TRIZ is difficult to access to chemical process safety due to inapplicability and ambiguity of terminology in classification of these parameters. It is necessary to be modified TRIZ for chemical process safety. This study reorganized thirty-nine parameters of the TRIZ into six categories such as mechanic, operator, process upset, design, natural hazard and material. The modified TRIZ is tested to jacketed reactor and polyethylene reactor.     

A comparative review for understanding elite interest and climate change policy in China

China’s climate change policy has rapidly evolved from one of neglect to necessity with sinologists drawing on a wide range of theories in trying to explain this shift. The rising influence of citizens' movements coupled with international pressure are often cited as significant drivers behind the government’s evolving climate change strategy. But can the influence of public pressure and international lobbying offer a complete explanation for the government’s dramatic policy changes? In this article, we advance theoretical pluralism where three contending schools of thought are made complementary to offer distinct explanations for understanding the mechanisms and rationale for Beijing’s elite-driven climate change policy. In brief, by bridging three separate theoretical streams including rational choice theory, authoritarian environmentalism and advocacy coalition framework, we show that the interests of elites in China’s upper political echelon are the driving force behind the country’s climate change policy.     

Alternative solid carbon source from dried attached-growth biomass for nitrogen removal enhancement in intermittently aerated moving bed sequencing batch reactor

The feasibility of using dried attached-growth biomass from the polyurethane (PU) foam cubes as a solid carbon source to enhance the denitrification process in the intermittently aerated moving bed sequencing batch reactor (IA-MBSBR) during the treatment of low COD/N containing wastewater was investigated. By packing the IA-MBSBR with 8 % (v/v) of 8-mL PU foam cubes saturated with dried attached-growth biomass, total nitrogen removal efficiency of 80 % could be achieved for 10 consecutive cycles of operation when the intermittent aeration strategy of consecutive 1 h of aeration followed by 2 h of non-aeration period during the REACT period of the IA-MBSBR was adopted. Negligible release of ammonium nitrogen (NH₄ ⁺–N) and slow-release of COD from the dried biomass would ensure that the use of this solid carbon source would not further burden the treatment system. The slow-releasing COD was found to have no effect in promoting the assimilation process and would also allow the carbon source to be used for many cycles of operation. The ‘carbon-spent’ PU foam cubes could be reused by merely drying at 60 °C at the end of the operational mode. Thus, the dried attached-growth biomass formed on the PU foam cubes could be exploited as an alternative solid carbon source for the enhancement of denitrification process in the IA-MBSBR.     

Effects of fine particles on children’s hospital admissions for respiratory health in Seville,Spain

This study analyzes the influence of fine particles PM_2.5 on nonprogrammed children’s hospital admissions that occurred in the city of Seville between 2007 and 2011, and makes an economic assessment of the cost of the children’s hospital admissions for respiratory causes due to particle pollution. The PM_2.5 dose-response functions for each type of hospital admission were used to quantify the cost of the hospital admissions. It can be concluded that the PM_2.5 concentrations have negative effects on bronchiolitis, pneumonia, asthma, and bronchitis and other causes. A reduction of the daily average annual PM_2.5 concentration from the existing levels to 10 µg/m³ would show an annual average reduction of children’s hospital admissions due to respiratory diseases of 0.09 cases. This paper shows that the daily average cost for children hospital admissions due to respiratory reasons in the city of Seville, associated with daily average annual levels of PM_2.5 above 10 µg/m³, was almost 200€.

Implications:?Elevated PM_2.5 concentrations in Seville have negative effects on children’s bronchiolitis, pneumonia, asthma, and bronchitis and other causes. A reduction of the daily average annual PM_2.5 concentration from the existing levels to 10 μg/m³ would suppose an annual mean reduction of children’s hospital admissions due to respiratory diseases of 0.09 cases.     

Volatile pollutants emitted from selected liquid household products

BACKGROUND, AIM, AND SCOPE: To identify household products that may be potential sources of indoor air pollution, the chemical composition emitted from the products should be surveyed. Although this kind of survey has been conducted by certain research groups in Western Europe and the USA, there is still limited information in scientific literature. Moreover, chemical components and their proportions of household products are suspected to be different with different manufacturers. Consequently, the current study evaluated the emission composition for 42 liquid household products sold in Korea, focusing on five product classes (deodorizers, household cleaners, color removers, pesticides, and polishes). MATERIALS AND METHODS: The present study included two phase experiments. First, the chemical components and their proportions in household products were determined using a gas chromatograph and mass spectrometer system. For the 19 target compounds screened by the first phase of the experiment and other selection criteria, the second phase was done to identify their proportions in the purged-gas phase. RESULTS: The number of chemicals in the household products surveyed ranged from 9 to 113. Eight (product class of pesticides) to 17 (product class of cleaning products) compounds were detected in the purged-gas phase of each product class. Several compounds were identified in more than one product class. Six chemicals (acetone, ethanol, limonene, perchloroethylene (PCE), phenol, and 1-propanol) were identified in all five product classes. There were 13 analytes occurring with a frequency of more than 10% in the household products: limonene (76.2%), ethanol (71.4%), PCE (66.7%), phenol (40.5%), 1-propanol (35.7%), decane (33%), acetone (28.6%), toluene (19.0%), 2-butoxy ethanol (16.7%), o-xylene (16.7%), chlorobenzene (14.3%), ethylbenzene (11.9%), and hexane (11.9%). All of the 42 household products analyzed were found to contain one or more of the 19 compounds. DISCUSSION: The chemical composition varied broadly along with the product classes or product categories, and it was different from that reported in other studies abroad, although certain target chemicals were identified in both studies. This finding supports an assertion that chemical components emitted from household products may be different in different products and with different manufacturers. The chlorinated pollutants identified in the present study have not been reported to be components of cleaning products in papers published since the early 1990s. Limonene was identified as having the highest occurrence in the household products in the present study, although it was not detected in any of 67 household products sold in the U.S. CONCLUSIONS: The emission composition of selected household products was successfully examined by purge-and-trap analysis. Along with other exposure information such as use pattern of household products and the indoor climate, this composition data can be used to estimate personal exposure levels of building occupants. This exposure data can be employed to link environmental exposure to health risk. It is noteworthy that many liquid household products sold in Korea emitted several toxic aromatic and chlorinated organic compounds. Moreover, the current finding suggests that product types and manufacturers should be considered, when evaluating building occupants' exposure to chemical components emitted from household products. RECOMMENDATIONS AND PERSPECTIVES: The current findings can provide valuable information for the semiquantitative estimation of the population inhalation exposure to these compounds in indoor environments and for the selection of safer household products. However, although the chemical composition is known, the emissions of household products might include compounds formed during the use of the product or compounds not identified as ingredients by this study. Accordingly, further studies are required, and testing must be done to determine the actual composition being emitted. Similar to eco-labeling of shampoos, shower gels, and foam baths proposed by a previous study, eco-labeling of other household products is suggested.     

Effects of driving conditions on diesel exhaust particulates

Four driving conditions were examined to characterize how speeds and loads of a medium-duty diesel engine affect resultant diesel exhaust particulates (DEPs) in terms of number concentrations (< or =400 nm), size distribution, persistent free radicals, elemental carbon (EC), and organic carbon (OC). At the medium engine load (60%), DEPs surged in number concentrations at around 40-70 nm, whereas DEPs from the full engine load (100%) showed a distinctive bimodal distribution with a large population of 30-50 nm and 100-400 nm. Under the full engine load, engine speeds insignificantly affected resultant DEP number concentrations. When the engine load decreased from 100% to the medium level (60%), DEPs of ultrafine size and 100-400 nm decreased at least 1.4 times (from 5.6 x 10(8) to 4 x 10(8) #/cm3) and more than 3 times (from 2.7 x 10(8) to 0.8 x 10(8) #/cm3), respectively. The same reduction in the engine load significantly decreased persistent free radicals in DEPs up to approximately 30 times (from 123 x 10(16) to 4 x 10(16) #spin/g). Decreasing the engine load from 100 to 60% also concurrently reduced both EC and OC in total DEPs around 2 times, from 27.3 to 13.9 mg/m3, and from 17.6 to 9.2 mg/m3, respectively. For DEPs smaller than 1 microm, under the full engine load, EC and OC consistently peaked at 170-330 nm under an engine speed of 1800 rpm or 94-170 nm under an engine speed of 3000 rpm, reflecting processes of nucleation, cluster-cluster agglomeration, and condensation. Decreasing the engine load from 100 to 60% reduced EC and OC in DEPs (smaller than 1 microm) at least 3 times (0.6 to 0.2 mg/m3) and 2 times (0.4 to 0.2 mg/m3), respectively. Taken together, decreasing the full engine load to a medium (60%) level effectively reduced the number concentrations (< or =400 nm), persistent free radicals, EC, and OC of total DEPs, as well as the concentration of EC and OC in ultrafine and accumulation-mode DEPs.     

Workplace offense and victims' reactions: the effects of victim‐offender (dis)similarity,offense‐type,and cultural differences

This study examined the effects of workplace offenders' characteristics and offense‐type on victims' reactions. Responses from 352 employed graduate students in the U.S. and South Korea to a hypothetical offense incident revealed that employees from the U.S. and Korea differ in their expressed desirability of avoiding, seeking revenge against, and reconciling with an offending coworker depending on the offenders' similarity/dissimilarity to the victim and on the type of offense. As expected, Koreans (but not U.S. Americans) were more likely to avoid and to seek revenge on a coworker whose offensive remark was group‐ rather than personally‐directed. In addition, Koreans were most motivated to reconcile when an offensive remark came from a similar rather than dissimilar coworker and when the offense targeted them personally (not their group). However, U.S. Americans were most motivated to reconcile when an offensive remark came from a similar rather than dissimilar other and when the offense targeted their group (not them personally). Copyright © 2008 John Wiley & Sons, Ltd.     

Application of magnetoelastic sensors for quantifying sediment deposition rates and sizes

This paper describes the application of magnetoelastic sensors for quantifying the size and deposition rate of sediment samples in costal areas, lakes, and rivers. The magnetoelastic sensor, which is made of inexpensive amorphous ferromagnetic alloy, measures parameters of interest by tracking the changes in its resonant frequency and/or amplitude. Since an increase in mass loading on the sensor surface changes its resonant frequency and amplitude, the deposition rate of sediment particles can be determined in real time by tracking these two quantities. Based on a theoretical model, the size distribution of the sediment particles was also estimated from the deposition rate.     

Transport impacts on atmosphere and climate: Aviation

Aviation alters the composition of the atmosphere globally and can thus drive climate change and ozone depletion. The last major international assessment of these impacts was made by the Intergovernmental Panel on Climate Change (IPCC) in 1999. Here, a comprehensive updated assessment of aviation is provided. Scientific advances since the 1999 assessment have reduced key uncertainties, sharpening the quantitative evaluation, yet the basic conclusions remain the same. The climate impact of aviation is driven by long-term impacts from CO₂ emissions and shorter-term impacts from non-CO₂ emissions and effects, which include the emissions of water vapour, particles and nitrogen oxides (NO_x). The present-day radiative forcing from aviation (2005) is estimated to be 55 mW m^?2 (excluding cirrus cloud enhancement), which represents some 3.5% (range 1.3–10%, 90% likelihood range) of current anthropogenic forcing, or 78 mW m^?2 including cirrus cloud enhancement, representing 4.9% of current forcing (range 2–14%, 90% likelihood range). According to two SRES-compatible scenarios, future forcings may increase by factors of 3–4 over 2000 levels, in 2050. The effects of aviation emissions of CO₂ on global mean surface temperature last for many hundreds of years (in common with other sources), whilst its non-CO₂ effects on temperature last for decades. Much progress has been made in the last ten years on characterizing emissions, although major uncertainties remain over the nature of particles. Emissions of NO_x result in production of ozone, a climate warming gas, and the reduction of ambient methane (a cooling effect) although the overall balance is warming, based upon current understanding. These NO_x emissions from current subsonic aviation do not appear to deplete stratospheric ozone. Despite the progress made on modelling aviation's impacts on tropospheric chemistry, there remains a significant spread in model results. The knowledge of aviation's impacts on cloudiness has also improved: a limited number of studies have demonstrated an increase in cirrus cloud attributable to aviation although the magnitude varies: however, these trend analyses may be impacted by satellite artefacts. The effect of aviation particles on clouds (with and without contrails) may give rise to either a positive forcing or a negative forcing: the modelling and the underlying processes are highly uncertain, although the overall effect of contrails and enhanced cloudiness is considered to be a positive forcing and could be substantial, compared with other effects. The debate over quantification of aviation impacts has also progressed towards studying potential mitigation and the technological and atmospheric tradeoffs. Current studies are still relatively immature and more work is required to determine optimal technological development paths, which is an aspect that atmospheric science has much to contribute. In terms of alternative fuels, liquid hydrogen represents a possibility and may reduce some of aviation's impacts on climate if the fuel is produced in a carbon-neutral way: such fuel is unlikely to be utilized until a ‘hydrogen economy’ develops. The introduction of biofuels as a means of reducing CO₂ impacts represents a future possibility. However, even over and above land-use concerns and greenhouse gas budget issues, aviation fuels require strict adherence to safety standards and thus require extra processing compared with biofuels destined for other sectors, where the uptake of such fuel may be more beneficial in the first instance.     

Organosulfates from glycolaldehyde in aqueous aerosols and clouds: Laboratory studies

Secondary organic aerosol (SOA) formation is enhanced on acidic seed particles; SOA also forms during cloud processing reactions where acidic sulfate is prevalent. Recently several studies have focused on the identification of organosulfates in atmospheric aerosols or smog chamber experiments, and upon the mechanism of formation for these products. We identify several organosulfate products formed during the laboratory OH radical oxidation of dilute aqueous glycolaldehyde in the presence of sulfuric acid. We propose a radical–radical reaction mechanism as being consistent with formation of these products under our experimental conditions. Using a kinetics model we estimate that organosulfates account for less than 1% of organic matter formed from these precursors during cloud processing. However, in wet acidic aerosols, where precursors are highly concentrated and acidic sulfate makes up close to half of the aerosol mass, this radical–radical reaction could account for significant organosulfate production.