Accuracy of approximate methods of uncertainty propagation in seismic loss estimation

In this paper the efficacy of an approximate method of uncertainty propagation, known as the first-order second-moment (FOSM) method, for use in seismic loss estimation is investigated. The governing probabilistic equations which define the Pacific Earthquake Engineering Research (PEER)-based loss estimation methodology used are discussed, and the proposed locations to use the FOSM approximations identified. The justification for the use of these approximations is based on a significant reduction in computational time by not requiring direct numerical integration, and the fact that only the first two moments of the distribution are known. Via various examples it is shown that great care should be taken in the use of such approximations, particularly considering the large uncertainties that must be propagated in a seismic loss assessment. Finally, a complete loss assessment of a structure is considered to investigate in detail the location where significant approximation errors are incurred, where caution must be taken in the interpretation of the results, and the computational demand of the various alternatives.     

Influence of Sulfur Poisoning on CO Adsorption on Pd(100)

Investigations of CO adsorption on sulfur covered Pd(100) surface were conducted in order to obtain insight into the deleterious effects of sulfur on this system. First-principles density functional theory calculations indicate that CO is markedly destabilized when it shares surface atoms with neighboring sulfur. Based on the analysis of the electronic properties, the decrease in binding is attributed to localized S?CPd bonding plus the interaction between CO and S. The internal C?CO stretching frequency was blue shifted relative to that on the clean surface as a result of the weakening of the C?CPd bonds. The poisoning effect is predicted to diminish for distant sites. Kinetic Monte Carlo simulations (with adsorbate lateral interactions included) revealed that the introduction of S creates competition for adsorption sites. At a finite temperature, CO adsorption is essentially nullified when the surface is covered by a quarter of monolayer of sulfur in agreement with experiments. Aside from reduction of possible adsorption sites, sulfur severely inhibits the mobility of CO as well.     

An integrated approach for water minimisation in a PVC manufacturing process

This paper presents a water minimisation study carried out for a polyvinyl chloride (PVC) resins manufacturing plant. Due to the complexity of the mixed batch and continuous polymerisation process, an integrated process integration approach, which consists of process synthesis, analysis and optimisation was used for this work. A simulation model was first developed in a batch process simulation software, SuperPro Designer V6.0, based on the operating condition of a PVC manufacturing process. The batch simulation model captured the essential information needed for a water minimisation study, e.g. process duration, water mass flow, etc. Data extracted from the simulation model was later used in the water minimisation study, utilising the widely established process synthesis technique of water pinch analysis. Two water saving scenarios were presented. Scenario 1 reports a fresh water and wastewater reduction of 28.5 and 90.1% respectively, for the maximum water recovery scheme without water storage system. In Scenario 2, higher fresh water and wastewater reduction are reported at 31.7 and 100% respectively, when water storage tank is installed in the water network.     

Hydroxyapatite pattern formation in PVA gels

Sodium hydroxide solution was allowed to diffuse from the edge of an acidic poly(vinyl alcohol) gel sheet containing dissolved calcium and phosphate ions, and calcium phosphate was observed to precipitate as the pH rose. The precipitation pattern changed depending on the solute concentration near the reaction front; precipitate “walls” were formed in areas in which the calcium phosphate concentration was higher or the sodium hydroxide concentration was lower than the conditions for homogeneous precipitation, and within a very limited concentration combination of calcium phosphate and sodium hydroxide, a regular stripe pattern with a pitch of about 100 μm was formed. The calcium phosphate precipitate obtained was a single phase of hydroxyapatite. It was also found that apatite ceramic sheets with periodic porous structures or with undulate patterns could be manufactured by sintering gels with stripe patterns.     

Quality is in the eye of the beholder? An evaluation of impact factors and perception of journal prestige in the UK

A number of proxy measures have been used as indicators of journal quality. The most recent and commonly employed are journal impact factors. These measures are somewhat controversial, although they are frequently referred to in establishing the impact of published journal articles. Within psychology, little is known about the relationship between the ‘objective’ impact factors of journals and the ‘subjective’ ratings of prestige and perceived publishing difficulty amongst academics. In order to address this, a cross-sectional web-based survey was conducted in the UK to investigate research activity and academics’ views of journals within three fields of psychology; cognitive, health and social. Impact factors for each journal were correlated with individual academic’s perceptions of prestige and publishing difficulty for each journal. A number of variables pertaining to the individual academic and their place of work were assessed as predictors of these correlation values, including age, gender, institution type, and a measure of departmental research activity. The implications of these findings are discussed in relation to perceptions of journal prestige and publishing difficulty, higher education in general and the assessment of research activity within academic institutions.     

Streamlined life cycle assessment of residue utilization options in <Emphasis Type="Italic">Tongkat Ali </Emphasis>(<Emphasis Type="Italic">Eurycoma longifolia</Emphasis>) water extract manufacturing process

Life cycle assessment (LCA) is often used to compare alternative process options in terms of their overall impact on the environment to easily identify the most environmentally friendly alternative. In this work, a streamlined LCA study was conducted to assess three different residue utilization schemes for Tongkat Ali (Eurycoma longifolia) extract production. The case study was firstly simulated using a batch process simulation software. The results of mass and energy balances obtained from the simulation software were then subjected to life cycle analysis. By evaluating the different schemes for using the fibrous residue from the extraction process, the potential for environmental process improvement was identified. Overall, use of the residue as process fuel was found to be the most environmentally friendly option. It produces the least emissions and reduces resource usage per unit of product than the other options evaluated.     

Disc Stack Centrifuge Operating Parameters and Their Impact on Yeast Physiology

Hydrodynamic stresses imposed on brewing cells of Saccharomyces cerevisiae during beer processing can have a detrimental impact on beer quality. The use of centrifuges has become an efficient way to increase brewery throughput as they decrease clarification times and improve fermenter and tank conditioning efficiency. The effect of a disc stack centrifuge on yeast and beer physical stability has been investigated. In this study, a commercial ale yeast strain has been subjected to different operating conditions during centrifugation. Cell viability and intracellular pH decreased due to processing conditions encountered during yeast cropping with a centrifuge. A relationship has been established that yeast cell wall mannan, an unfilterable haze constituent, as a function of G‐force and centrifugation cycles, is released from the cell wall while concurrently, particle sizes between 0.5‐2.8 μm and beer haze increased. Furthermore, yeast intracellular glycogen and trehalose levels were depleted as a result of centrifugation.     

A systematic literature review on state-of-the-art deep learning methods for process prediction

Artificial Intelligence Review - Process mining enables the reconstruction and evaluation of business processes based on digital traces in IT systems. An increasingly important technique in this...     

Biology,Pest Status,Microbiome and Control of Kudzu Bug (Hemiptera: Heteroptera: Plataspidae): A New Invasive Pest in the U.S.

Soybean is an important food crop, and insect integrated pest management (IPM) is critical to the sustainability of this production system. In recent years, the introduction into the United States of the kudzu bug currently identified as Megacopta cribraria (F.), poses a threat to soybean production. The kudzu bug was first discovered in the state of Georgia, U.S. in 2009 and since then has spread to most of the southeastern states. Because it was not found in the North American subcontinent before this time, much of our knowledge of this insect comes from research done in its native habitat. However, since the U.S. introduction, studies have been undertaken to improve our understanding of the kudzu bug basic biology, microbiome, migration patterns, host selection and management in its expanding new range. Researchers are not only looking at developing IPM strategies for the kudzu bug in soybean, but also at its unique relationship with symbiotic bacteria. Adult females deposit bacterial packets with their eggs, and the neonates feed on these packets to acquire the bacteria, Candidatus Ishikawaella capsulata. The kudzu bug should be an informative model to study the co-evolution of insect function and behavior with that of a single bacteria species. We review kudzu bug trapping and survey methods, the development of bioassays for insecticide susceptibility, insecticide efficacy, host preferences, impact of the pest on urban environments, population expansion, and the occurrence of natural enemies. The identity of the kudzu bug in the U.S. is not clear. We propose that the kudzu bug currently accepted as M. cribraria in the U.S. is actually Megacopta punctatissima, with more work needed to confirm this hypothesis.     

Targeting and design for batch regeneration and total networks

Resource conservation for batch processes is gaining good attention in recent years. This is mainly due to the recent trend in chemical engineering that focuses on product engineering, as well as in the rise of various low volume and high value-added products (e.g. pharmaceutical, specialty chemicals, etc.) in the market. In this study, a systematic procedure to perform targeting and design of a batch resource conservation network (RCN) involving material regeneration and waste treatment (also known as a total RCN) is proposed. The procedure is applicable for all fixed-schedule-type batch RCNs with mass storage facilities. Literature examples are used to elucidate the proposed procedure.