Oxygen Reduction Reaction on Metal-Terminated MnCr2O4 Nano-octahedron Catalyzing MnS Dissolution in an Austenitic Stainless Steel

To understand pitting corrosion in stainless steel is very important, and a recent work showed that the MnS dissolution catalyzed by MnCr2O4{111} is a starting point of pit g. This demonstrates the need to understand the oxygen reduction reaction (ORR) on MnCr2O4{111}, which is the other half-reaction to complete pitting corrosion. In this study, the adsorption behaviors of all oxygen-containing species on MnCr2O4{111}, which has several possible terminations, are explored via density functional theory calculations. It is found that O-2 adsorbs on MnCr2O4{111) surfaces very strongly. Many possible reactions are investigated and the favored reaction mechanism of ORR is determined. The interactions between O-2 and H2O on the two metal-terminated MriCr(2)O(4){111} are found to be different according to the atomic configurations of the two surfaces. All the calculated results suggest that ORR can readily occur on the MnCr2O4{111} surfaces.

Hierarchical Demand Response for Peak Reduction using Dantzig‐Wolfe Decomposition

Demand Response (DR) algorithms manipulate the energy consumption schedules of controllable loads so as to satisfy grid objectives. Implementation of DR algorithms using a centralised agent can be problematic for scalability reasons, and there are issues related to the privacy of data and robustness to communication failures. Thus it is desirable to use a scalable decentralised algorithm for the implementation of DR. In this paper, a hierarchical DR scheme is proposed for Peak Minimisation (PM) based on Dantzig-Wolfe Decomposition (DWD). In addition, a Time Weighted Maximisation option is included in the cost function which improves the Quality of Service for devices seeking to receive their desired energy sooner rather than later. The paper also demonstrates how the DWD algorithm can be implemented more efficiently through the calculation of the upper and lower cost bounds after each DWD iteration.

Reduction of Carbon Dioxide to Formate at Low Overpotential using a Superbase Ionic Liquid

A new low-energy pathway is reported for the electrochemical reduction of CO2 to formate and syngas at low overpotentials, utilizing a reactive ionic liquid as the solvent. The superbasic tetraalkyl phosphonium ionic liquid [P66614][124Triz] is able to chemisorb CO2 through equimolar binding of CO2 with the 1,2,4-triazole anion. This chemisorbed CO2 can be reduced at silver electrodes at overpotentials as low as 0.17 V, forming formate. In contrast, physically absorbed CO2 within the same ionic liquid or in ionic liquids where chemisorption is impossible (such as [P66614][NTf2]) undergoes reduction at significantly increased overpotentials, producing only CO as the product.

Labeled 15NO experiments for the study of NOx reduction over Pt-Ba/Al2O3 LNT catalyst

Kinetics of methylene blue (MB) photocatalyzed reduction and dark regeneration in a colorimetric oxygen sensor

Performance data for a dye based, regenerable oxygen sensor (Mills and Lawrie [1], Mills et al. [2]) are analyzed to develop useful kinetic models for sensor photoactivation (dye reduction) and dark, oxygen detection (dye oxidation). The titania loaded, thin film sensor exhibits an apparent first order photoactivation of the dye, which we demonstrate (Section 3.2 and Fig. 4) is due to a kinetic disguise of a zero order photoreaction occurring through a non-uniformly illuminated sensor film. The observed zero order, slow recovery due to dye oxidation by dioxygen (O2 detection) appears best rationalized by a model assuming a near O2-impermeable skin developing on the sensor surface as solvent is evaporatively removed following sensor film casting and curing.

Corneal hysteresis is correlated with reduction in axial length after trabeculectomy.

BACKGROUND: We sought to determine whether corneal biomechanical parameters are predictive of reduction in axial length after anti-metabolite trabeculectomy. METHODS: Chinese subjects undergoing trabeculectomy with mitomycin C by a single experienced surgeon underwent the following measurements: Corneal hysteresis (CH, Ocular Response Analyzer, Reichert Ophthalmic Instruments), Goldmann intra-ocular pressure (IOP), central corneal thickness (CCT) and axial length (AL, IOLMaster, Carl Zeiss Meditec, Dublin, CA) were measured pre-operatively, and AL, CH and IOP were measured 1 day and 1 week post-operatively. RESULTS: Mean age of 31 subjects was 52.0 ± 15.2 years, and 15 (48.4%) were female. The mean pre-operative IOP of 21.4 ± 9.3 mmHg was reduced to 8.2 ± 4.6 mmHg 1 day and 11.0 ± 4.4 mmHg 1 week post-operatively (p < 0.001). AL declined from 22.99 ± 0.90 to 22.76 ± 0.87 mm at 1 day and 22.74 ± 0.9 mm at 1 week; 30/31 (%) eyes had a decline in AL (p < 0.001, sign test). In multivariate linear regression models including post-operative data from 1 day and 1 week, greater decline in Goldmann IOP (p < 0.0001, greater pre-op axial length (p < 0.001) and lower pre-operative CH (p = 0.03), were all associated with greater decline in post-operative axial length. CONCLUSIONS: Eyes with lesser ability of the ocular coat to absorb energy (lower CH) had significantly greater decrease in axial length after trabeculectomy-induced IOP-lowering.

Strength reduction of till under dynamic pore pressure condition

Cuttings in heavily overconsolidated clays are known to be susceptible to progressive deformation caused by creep and fatigue that usually begins at the toe of the slope. The progressive deformation leads to strength reduction with time at constant stress (or called softening) and could be accelerated by fluctuation of groundwater level associated with more extreme rainfall events predicted through climate change. The purpose of this paper is to assess the mechanism of progressive deformation due to creep and fatigue using element testing on samples of till. The samples were subjected to fully drained loading and the deviator stresses were held constant at various percentages of peak failure stress, while the pore water pressure was kept static or dynamic (fluctuating ±5 kPa) over a period of time. The results have shown that the samples experienced significant deformation even at a higher factor of safety (i.e. the failure deviator stress/deviator stress at which the pore water pressure was fluctuated) under pore water pressure dynamics.

Assessing the effect of reducing agents on the selective catalytic reduction of NOx over Ag/Al2O3 catalysts

The selective catalytic reduction (SCR) of NOx in the presence of different reducing agents over Ag/Al2O3 prepared by wet impregnation was investigated by probing catalyst activity and using NMR relaxation time analysis to probe the strength of surface interaction of the various reducing agent species and water. The results reveal that the strength of surface interaction of the reducing agent relative to water, the latter present in engine exhausts as a fuel combustion product and, in addition, produced during the SCR reaction, plays an important role in determining catalyst performance. Reducing agents with weak strength of interaction with the catalyst surface, such as hydrocarbons, show poorer catalytic performance than reducing agents with a higher strength of interaction, such as alcohols. This is attributed to the greater ability of oxygenated species to compete with water in terms of surface interaction with the catalyst surface, hence reducing the inhibiting effect of water molecules blocking catalyst sites. The results support the observations of earlier work in that the light off-temperature and maximum NOx conversion and temperature at which that occurs are sensitive to the reducing agent present during reaction, and the proposal that improved catalyst performance is caused by increased adsorption strength of the reducing agent, relative to water, at the catalyst surface. Importantly, the NMR relaxation time analysis approach to characterising the strength of adsorption more readily describes the trends in catalytic behaviour than does a straightforward consideration of the polarity (i.e., relative permittivity) of the reducing agents studied here. In summary, this paper describes a simple approach to characterising the interaction energy of water and reducing agent so as to aid the selection of reducing agent and catalyst to be used in SCR conversions.

A Slow March from Social Evil to Harm Reduction: Drugs and Drug Policy in Vietnam

The suppression of drug consumption and trade is high on the Government of Vietnam’s agenda. To accomplish this goal, Vietnam employs repressive policies that often contravene international human rights law. Among the most detrimental and problematic policies are the incarceration of drug users in compulsory treatment centers, and the stigmatization and abuse of consumers by the police. That said, Vietnamese drug policy is slowly changing in the face of one of Asia’s worst ongoing HIV epidemics. While the Communist Government of the early-1990s designated illicit drugs as a “social evil” to be eradicated through punitive and often repressive means, the recent implementation of harm reduction approaches have reduced the level of needle sharing, and thus HIV transmission. This briefing will explore the current trends in drug consumption, production, and trafficking before looking at the key harms and threats associated with drugs in Vietnam. This will be followed by a summary of Vietnam’s drug policies, including the country’s approach to drug treatment, harm reduction, and illicit opium suppression—Vietnam is one of a small number of states to have suppressed illicit opium production, an intervention that centred upon coercive negotiations with limited alternative development. The briefing will conclude with some tentative recommendations for reform and thoughts on what could be expected from Vietnam during the Special Session of the United Nations General Assembly on the World Drug Problem (UNGASS 2016).

EU water framework directive: will the nitrate load reduction from diffuse sources produce the same results in all estuaries?

The impact of urban waste-water and non-point nitrate discharges in estuarine and near-shore coastal waters are analyzed. The study is focused on the effects of applying the European directives 91/271/EEC and 91/676/EEC to these systems. 4 Portuguese estuaries and two coastal lagoons with different characteristics are studied. A modelling system is applied and calibrated in each system. Three nitrate load scenarios are examined. It is shown that the morphologic and hydrodynamic characteristics of the domain largely control the ecological processes in these systems. The primary production limitation factors are split into “biologic” and “hydrodynamic” components. The physical limitation due to hydrodynamic and residence time is the most important factor. The combined limitation of “biologic” factors (temperature, light and nutrients availability) control productivity only in the systems where physical limitation is not important.

Reduction vs acetalisation of some carbonyl-compounds by means of methylselenol and lewis-acids

Aliphatic ketones and aromatic carbonyl compounds on reaction with methylselenol :and a Lewis acid, are shown to undergo acetalisation and/or reduction to methyl selenide, the unexpected reduction reaction being predominant in most cases.