Structural investigation of the promotional effect of hydrogen during the selective catalytic reduction of NOx with hydrocarbons over Ag/Al2O3 catalysts

In situ EXAFS has been used to examine the hydrogen effect on the selective catalytic reduction of NOx over silver/alumina catalysts. For all SCR conditions used, with or without co-reductant (H-2 or CO), the catalyst structure remained the same. Significant changes in the catalyst were only found under reducing conditions. The enhanced activity found in the presence of hydrogen is thought to be due to a chemical effect and not the result of a change in the structure of the active site.

The opportunities and limitations of using CFD in the development of wave energy converters

Most Wave Energy Converters (WECs) being developed are fundamentally different from known marine structures. Limited experience is a fundamental challenge for the design, especially issues concerning load assumptions and power estimates. Reynolds-Averaged Navier-Stokes (RANS) CFD methods are being used successfully in many areas of marine engineering. They have been shown to accurately simulate many hydrodynamic effects and are a helpful tool for investigating complex flows. The major drawback is the significant computational power required and the associated overhead with pre and post-processing. This paper presents the challenges and advantages in the application of RANS CFD methods in the design process of a wave energy converter and compares the time, labour and ultimately financial requirements for obtaining practical results.

TBX2 represses CST6 resulting in uncontrolled legumain activity to sustain breast cancer proliferation: a novel cancer-selective target pathway with therapeutic opportunities.

TBX2 is an oncogenic transcription factor known to drive breast cancer proliferation. We have identified the cysteine protease inhibitor Cystatin 6 (CST6) as a consistently repressed TBX2 target gene, co-repressed through a mechanism involving Early Growth Response 1 (EGR1). Exogenous expression of CST6 in TBX2-expressing breast cancer cells resulted in significant apoptosis whilst non-tumorigenic breast cells remained unaffected. CST6 is an important tumor suppressor in multiple tissues, acting as a dual protease inhibitor of both papain-like cathepsins and asparaginyl endopeptidases (AEPs) such as Legumain (LGMN). Mutation of the CST6 LGMN-inhibitory domain completely abrogated its ability to induce apoptosis in TBX2-expressing breast cancer cells, whilst mutation of the cathepsin-inhibitory domain or treatment with a pan-cathepsin inhibitor had no effect, suggesting that LGMN is the key oncogenic driver enzyme. LGMN activity assays confirmed the observed growth inhibitory effects were consistent with CST6 inhibition of LGMN. Knockdown of LGMN and the only other known AEP enzyme (GPI8) by siRNA confirmed that LGMN was the enzyme responsible for maintaining breast cancer proliferation. CST6 did not require secretion or glycosylation to elicit its cell killing effects, suggesting an intracellular mode of action. Finally, we show that TBX2 and CST6 displayed reciprocal expression in a cohort of primary breast cancers with increased TBX2 expression associating with increased metastases. We have also noted that tumors with altered TBX2/CST6 expression show poor overall survival. This novel TBX2-CST6-LGMN signaling pathway, therefore, represents an exciting opportunity for the development of novel therapies to target TBX2 driven breast cancers.

Investigating the promotional effect of methanol on the low temperature SCR reaction on Ag/Al2O3

Methanol has been shown to promote the hydrocarbon selective catalytic reduction of NO with octane and toluene over 2wt% Ag/AlO catalyst for the first time. In order to understand its role in the reaction fast transient kinetic methods and in situ DRIFTS analysis have been used. The catalytic activity tests showed that the addition of methanol to the HC-SCR reaction results in a significant improvement in the low temperature activity of a Ag/AlO catalyst, despite the fact that methanol on its own is not reactive for the HC-SCR reaction. This promotional effect of methanol is dependent on the concentration of added methanol and is not necessarily associated with a higher concentration of reductant in the SCR feed. The fast transient kinetic analysis has shown that at each temperature the addition of methanol enhances the conversions of both NO and octane and the production of N with high selectivity in comparison with those observed with n-octane or toluene alone. This phenomenon is similar to the effect of H which may be associated with the release of hydrogen and ammonia during the transient switches at 250 and 300°C. Together with the fast transient experiments, the DRIFTS results showed that NCO species are formed when introducing methanol to the n-octane-SCR feed while CN species are removed/consumed from the surfaces of the Ag catalyst. These NCO species formed by adding methanol may play a vital role in promoting the catalytic activity of NO reduction and methanol itself can be an in situ source for hydrogen formation, which subsequently enhances the SCR reaction. © 2014 Elsevier B.V.

The Reintegration of Sex Offenders: Barriers and Opportunities for Employment

The process of reintegration of offenders after release from prison, or during a community sentence, is a key aim of criminal justice policy. This article provides details from recent research that investigated the barriers and opportunities to employment for sex offenders. The authors describe the barriers that are faced by sex offenders and the anxieties that employers experience when employing sex offenders. The authors conclude that the approach taken by the State is less than reintegrative and serves to increase the barriers and reduce the opportunities for employment for sex offenders.