Flexible operation of CSIRO's post-combustion CO2 capture pilot plant at the AGL Loy Yang power station

Flexible operation has the potential to significantly improve the economic viability of post-combustion CO2 capture (PCC). However, the impact of disturbances from flexible operation of the PCC process is unclear. The purpose of this study was to investigate the effects of flexible operation in a PCC pilot plant by implementing step-changes for improved dynamic data reliability. The flexible operation campaign was conducted at the CSIRO PCC pilot plant at AGL Loy Yang using monoethanolamine (MEA) absorbent. The pilot plant was operated under a broad range of transient conditions (changing flue gas flow, liquid absorbent flow and steam pressure) to capture the dynamics of a PCC process during flexible operation. The study demonstrated that the dynamics of flue gas flow rate was faster than absorbent flow rate. The greatest CO2 removal% was achieved at the lowest flue gas flow rate or at the highest absorbent flow rate; however, the latter provided improved energy efficiency. The steam pressure parameter could adjust the temperature of all columns simultaneously which can be used to compensate for effects from ambient conditions or heat losses. These results verify the technical feasibility of flexible PCC operation and provide a suitable dataset for dynamic model validation

Estimation of toxicity of chemical mixtures through modeling of chemical interactions.

The Agency for Toxic Substances and Disease Registry (ATSDR), in collaboration with the Dutch Organization for Applied Scientific Research (TNO) Nutrition and Food Research Institute, is conducting studies to evaluate the role of chemical interactions in the expression of toxicity from low-level exposure to combinations of chemicals. The goal of this collaborative effort is to use a weight-of-evidence (WOE) approach to estimate joint toxicity of some simple chemical mixtures and to compare the estimations with test results from animal toxicity studies. The WOE approach uses individual chemical dose-response assessments and algorithms that incorporate various assumptions regarding potential chemical interactions. Qualitative evaluations were prepared for binary combinations of chemicals for the effect of butyl hydroxyanisole on di(2-ethylhexyl)phthalate, the effect of stannous chloride on Cd chloride (CdCl2), and the effect of CdCl2 on loperamide. Analyses of these evaluations and their comparison with the conclusions of laboratory animal experiments indicate that the WOE approach can be used to estimate qualitatively the joint toxicity of such simple mixtures. To further test the utility of the WOE approach, qualitative and semiquantitative evaluations were prepared for two chemical mixtures--one with similarly acting halogenated aliphatics (trichloroethylene, tetrachloroethylene, hexachloro-1,3-butadiene[HCBD], and 1,1,2-trichloro-3,3,3-trifluoropropene [TCTFP]) and the other with dissimilarly acting nephrotoxic components (mercuric chloride, lysinolalanine, D-limonene, and HCBD). These two sets of data were used to estimate the overall toxicities of the mixtures using the WOE algorithm for the mixture. The comparison of the results of the estimated toxicity with experimentally determined toxicity of the mixture of similarly acting nephrotoxicants demonstrated that the WOE approach correctly adjusted for the observed interactions in experimental animal studies. However, this was not true for the mixture of dissimilarly acting nephrotoxicants. This could be attributed to the fact that WOE evaluations are based on dose additivity that postulates that all chemicals in a given mixture act in the same way--by the same mechanism--and differ only in their potencies. In these cases the WOE approach evaluations, based on consideration of common mechanisms for simple chemical mixtures, can lead to better estimates of joint toxicity of chemical mixtures than the default assumption of dose additivity. The results also show that the WOE evaluations should be target-organ specific because none of the models tested could approximate the observed responses in organs other than the target organs in the laboratory animal studies

Stakeholder perspectives on primary school pupils and sickness absence:Exploring opportunities and challenges

School absenteeism and its underlying causes can have negative effects on the cognitive, psychosocial and health development of a child. Research in primary education shows high rates of sickness absence. Many stakeholders are involved in addressing school absenteeism, including primary school professionals, child and youth healthcare physicians, school attendance officers and parents. This study explores these stakeholders’ perspectives, their approaches and what they envisage to be necessary in order to improve. It also aims to unveil opportunities and challenges in addressing sickness absence among primary school pupils. Qualitative research was performed with six semi-structured focus group interviews and involving 27 participants from the West-Brabant and Amsterdam regions of the Netherlands. Thematic analysis was used. The overarching theme was aiming for the child’s wellbeing. Each focus group interview started with low awareness of sickness absence as a threat to this wellbeing, but awareness grew during the interviews. The participating stakeholders regarded problematic sickness absence as complex due to a wide variety of causes, and felt that each other’s expertise was necessary to reduce sickness absence. Schools registered absence, but only occasionally used planned steps; they based the identification of problematic sickness on gut feeling rather than any agreed-upon criteria. To be able to systematically address sickness absence and thus improve the wellbeing of children, stakeholders felt the need for a clearly structured approach, including monitoring of sickness absence of all pupils, identifying problematic absence and promoting collaboration with other stakeholders. An approach should allow for tailoring solutions to the individual child

The Value of Suction Drainage Fluid Culture during Aseptic and Septic Orthopedic Surgery: A Prospective Study of 901 Patients

There are no guidelines on the value of suction drainage fluid culture (SDC), and it is difficult to determine whether the organisms cultured from suction drainage fluid samples are pathogenic or simply contaminants. We performed 2989 cultures of suction drainage fluid samples obtained, during a 1-year period, from 901 patients who underwent aseptic or septic orthopedic surgery (946 operations). The culture results were analyzed to evaluate their ability to detect postoperative infection after aseptic operations or to detect either a persistent or new episode of sepsis in patients known to have infection. For aseptic operations, the sensitivity of SDC was 25%, the specificity was 99%, the positive predictive value was 25%, and the negative predictive value was 99%. For septic operations, the sensitivity of SDC was 81%, the specificity was 96%, the positive predictive value was 87%, and the negative predictive value was 94%. We conclude that, for aseptic orthopedic surgery, SDC is not useful in detecting postoperative infection. However, for septic orthopedic surgery, it is of clinical importanc

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

Peer reviewedPublisher PD