Computational investigation of hydraulic performance variation with geometry in gabion stepped spillways

Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.     

Optimisation of cogeneration system and fuel inventory with automated targeting model

Clean Technologies and Environmental Policy - Industrial wastes can be used as alternative fuel sources for the substitution of fossil fuel if they contain good calorific values. Through...     

Radiochemical Investigation of Blade Cleaning Lubricants

Operation of an elastomeric blade requires the use of a boundary lubricant to remove residual xerographic toner from the photoreceptor efficiently. A radioactive tracer technique was used to study the behaviour of a number of lubricants used in the xerographic process. Both filming and nonfilming type lubricants were investigated using this technique. The results indicated that the lubricant film deposited on the photoreceptor must be in the thickness range of from 1 to 3 molecular layers for acceptable xerographic development and cleaning. Film thickness was shown to be dependent on the class of lubricant, the concentration of lubricant in toner, and the inclusion of a silica compound in the toner. Films are dynamic in nature, continuously being formed and removed during the xerographic process. Parameters affecting the filming mechanism are discussed.     

Evaluation of long-term effects of rejuvenation on reclaimed binder properties based on chemical-rheological tests and analyses

This study used multiple chemical-rheological tests to investigate the long-term characteristics of rejuvenating agents in reclaimed asphalt binders. To this end, a base binder and its blending with an extracted binder obtained from recycled asphalt pavements were selected, and two different types of rejuvenating agents: agriculture-based and petroleum-based agents were used to modify the blended binder. The base binder and the blended binders that were modified by the two rejuvenators were then aged using a typical laboratory long-term aging procedure. The chemical studies included: a saturates-aromatics-resins-asphaltenes analysis, Fourier transform infrared spectroscopy, and elemental (carbon, hydrogen, nitrogen, sulfur and oxygen) analysis. The rheological tests primarily investigated the linear viscoelastic properties through aging and rejuvenation. The effects of rejuvenators on restoration were quite material-dependent, which was related to the different chemical compositions of the rejuvenators and their chemical-molecular interactions with the parent binder. The tests and analysis results showed that the immediate effects of rejuvenators are mostly the result of the addition of lighter molecules in rejuvenators, while the long-term effects were material-specific and further chemistry-driven. From the two rejuvenating agents studied herein, the petroleum-based material improves performance of the binder in the next round of service by preserving the chemical composition and maintaining the stability, whereas the agriculture-based agent used in this study might increase the aging issues because of its pre-existing high oxygen content, which could negatively affect long-term durability over service period.     

Towards Quantitative and Standardized Serological and Neutralization Assays for COVID-19

Quantitative and robust serology assays are critical measurements underpinning global COVID-19 response to diagnostic, surveillance, and vaccine development. Here, we report a proof-of-concept approach for the development of quantitative, multiplexed flow cytometry-based serological and neutralization assays. The serology assays test the IgG and IgM against both the full-length spike antigens and the receptor binding domain (RBD) of the spike antigen. Benchmarking against an RBD-specific SARS-CoV IgG reference standard, the anti-SARS-CoV-2 RBD antibody titer was quantified in the range of 37.6 µg/mL to 31.0 ng/mL. The quantitative assays are highly specific with no correlative cross-reactivity with the spike proteins of MERS, SARS1, OC43 and HKU1 viruses. We further demonstrated good correlation between anti-RBD antibody titers and neutralizing antibody titers. The suite of serology and neutralization assays help to improve measurement confidence and are complementary and foundational for clinical and epidemiologic studies.     

Process-to-Policy (P2Pol): using carbon emission pinch analysis (CEPA) tools for policy-making in the energy sector

Clean Technologies and Environmental Policy - Global warming is a major international issue due to rising levels of greenhouse gases such as CO2. Many countries now face the challenge to find...     

Efficient Generation of Hydrazides in Proteins by RadA Split Intein

Protein C-terminal hydrazides are useful for bioconjugation and construction of proteins from multiple fragments through native chemical ligation. To generate C-terminal hydrazides in proteins, an efficient intein-based preparation method has been developed by using thiols and hydrazine to accelerate the formation of the transient thioester intermediate and subsequent hydrazinolysis. This approach not only increases the yield, but also improves biocompatibility. The scope of the method has been expanded by employing Pyrococcus horikoshii RadA split intein, which can accommodate a broad range of extein residues before the site of cleavage. The use of split RadA minimizes premature intein N cleavage in vivo and offers control over the initiation of the intein N cleavage reaction. It is expected that this versatile preparation method will expand the utilization of protein C-terminal hydrazides in protein preparation and modification.     

Risk assessment in the maintenance of offshore caisson operations

Undertaking maintenance of offshore caissons is a pervasive challenge that involves an array of risks and uncertainties. Despite the adoption of standardised and routine maintenance procedures that are subject to on-going improvements, the rate of failure in offshore caissons remains relatively high. To manage the effect of risk and uncertainties associated with the maintenance of offshore caissons, expert judgment can be drawn upon to better understand and capture the issues that contribute to their failure. Using a case study of an offshore hydrocarbon discharge caisson in the North Sea of the United Kingdom, expert judgements from industry practitioners are obtained using the Delphi Interview and Analytic Hierarchy Process (AHP) technique to rank 14 possible recovery options. Sensitivity analysis is used to ascertain the suitability of each of the options. Results reveal that the Delphi technique employed provided a robust means to garner invaluable insights from experts about the issues associated with caisson failure. The corollary is the development of a framework that serves as a point of reference to identify and assess the risks in offshore caisson maintenance operations. This framework can also be used in conjunction with existing probabilistic methods to improve the effectiveness of decision-making during operations and maintenance.     

Cognition and social adversity in the depressed elderly.

This study investigated the cognitive patterns and social circumstances of the depressed elderly. Compared to elderly nondepressed controls, the depressed elderly reported more negative thoughts, hopelessness, and dysfunctional attitudes. Although severe life events were more common in the depressed group, social adversity was unrelated to scores on these cognitive measures. Furthermore, when compared with findings using younger adults, our results suggest that the age of the depressed person has little effect on cognitions in general, with the possible exception of automatic thoughts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)