Questioning, exploring, narrating and playing in the control room to maintain system safety

Systems whose design is primarily aimed at ensuring efficient, effective and safe working, such as control rooms, have traditionally been evaluated in terms of criteria that correspond directly to those values: functional correctness, time to complete tasks, etc. This paper reports on a study of control room working that identified other factors that contributed directly to overall system safety. These factors included the ability of staff to manage uncertainty, to learn in an exploratory way, to reflect on their actions, and to engage in problem-solving that has many of the hallmarks of playing puzzles which, in turn, supports exploratory learning. These factors, while currently difficult to measure or explicitly design for, must be recognized and valued in design.     

Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems

Sustainable design and implementation of greywater reuse (GWR) has to achieve an optimum compromise between costs and potable water demand reduction. Studies show that GWR is an efficient tool for reducing potable water demand. This study presents a multi-objective optimization model for estimating the optimal distribution of different types of GWR homes in an existing municipal sewer system. Six types of GWR homes were examined. The model constrains the momentary wastewater (WW) velocity in the sewer pipes (which is responsible for solids movement). The objective functions in the optimization model are the total WW flow at the outlet of the neighborhoods sewer system and the cost of the on-site GWR treatment system. The optimization routing was achieved by an evolutionary multi-objective optimization coupled with hydrodynamic simulations of a representative sewer system of a neighborhood located at the coast of Israel. The two non-dominated best solutions selected were the ones having either the smallest WW flow discharged at the outlet of the neighborhood sewer system or the lowest daily cost. In both solutions most of the GWR types chosen were the types resulting with the smallest water usage. This lead to only a small difference between the two best solutions, regarding the diurnal patterns of the WW flows at the outlet of the neighborhood sewer system. However, in the upstream link a substantial difference was depicted between the diurnal patterns. This difference occurred since to the upstream links only few homes, implementing the same type of GWR, discharge their WW, and in each solution a different type of GWR was implemented in these upstream homes. To the best of our knowledge this is the first multi-objective optimization model aimed at quantitatively trading off the cost of local/onsite GW spatially distributed reuse treatments, and the total amount of WW flow discharged into the municipal sewer system under unsteady flow conditions.     

McGauran Giannini Soon Architects

Shelley Penn describes how a Melbourne-based practice's aspirations for integrity and authenticity have led it away from the usual pursuit of an identifiable visual language and style above content.     

探索空间的前沿 ——比尔·希列尔(1937—2019)

通过该文,艾伦·佩恩向比尔·希列尔(1937—2019)致敬.比尔是空间句法的创始人,创造了空间模式的分析方法.作为学术大师,比尔在科学领域中建立空间句法,整合了理论探索与规划设计实践.艾伦描述了空间句法的发展历史,以及比尔对建筑设计和城市规划学科的贡献.     

Effects of monovalent cations on the competitive adsorption of perfluoroalkyl acids by kaolinite: experimental studies and modeling

Our hypothesis that longer-chained perfluoroalkyl acids (PFAAs) outcompete shorter-chained PFAAs during adsorption was tested in this study, wherein the adsorption interactions of six frequently detected PFAAs with kaolinite clay were modeled and examined experimentally using various suspension compositions. Competitive adsorption of PFAAs on the kaolinite surface was observed for the first time, and longer-chained PFAAs outcompeted those with a shorter chain. The electrostatic repulsion between adsorbed PFAA molecules is a primary inhibitory factor in PFAA adsorption. An increase in aqueous sodium or hydrogen ion concentration weakened electrostatic repulsions and changed the adsorption free energy. Therefore, the adsorption of a shorter-chained PFAA with weaker hydrophobicity could occur at high sodium or hydrogen ion concentrations. The experimental and modeling data suggest that the adsorption of shorter-chained PFAAs (≤4 perfluorinated carbons) in freshwater with a typical ionic strength of 10(-2.5) is not thermodynamically favorable. Furthermore, by measuring the electrokinetic potential of kaolinite suspension in the presence of PFAAs, we found that the kaolinite surface became more negatively charged because of the adsorption of PFAAs. This observation indicates that the adsorbed PFAA molecules were within the electrical double layer of the kaolinite surface and that they contributed to the potential at the slipping plane. The possible alignments of adsorbed PFAA molecules on the kaolinite surface were then proposed.     

Compound muscle action potential amplitude and area changes in normal subjects and patients with carpal tunnel syndrome

Miyoshi-type distal muscular dystrophy (MMD) is an autosomal recessively inherited progressive disorder. The putative locus of MMD is linked to the limb-girdle muscular dystrophy 2B locus on chromosome 2p12-14. In this study three of four MMD pedigrees show non-linkage to the region spanned by D2S134-D2S358-D2S145 on chromosome 2p, indicating genetic heterogeneity. A genome wide screen was performed to identify loci linked to MMD. In two non-chromosome 2-linked families, a 23 cM region on chromosome 10 segregated with MMD.     

Panel VI: Ethnic minorities, health care systems, and behavior.

This article presents an overview of research on health care use and provider behavior, on doctor–patient relationships, adherence to medical regimens, self-care, practices and avoidance health care behaviors, and attitudes of 4 ethnoracial groups: African Americans, American Indians, Asian Americans, and Latinos. Although issues within the groups varied, common themes between the groups emerged. It became apparent, after discussion, that whatever the issues and health problems, these can be resolved most effectively when addressed within the social contexts of each ethnoracial group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single injection thermodilution. A flow-corrected method

BACKGROUND: Application of the Stewart-Hamilton equation in the thermodilution technique requires flow to be constant. In patients in whom ventilation of the lungs is controlled, flow modulations may occur leading to large errors in the estimation of mean cardiac output. METHODS: To eliminate these errors, a modified equation was developed. The resulting flow-corrected equation needs an additional measure of the relative changes of blood flow during the period of the dilution curve. Relative flow was computed from the pulmonary artery pressure with use of the pulse contour method. Measurements were obtained in 16 patients undergoing elective coronary artery bypass surgery. In 11 patients (group A), pulmonary artery pressure was measured with a catheter tip transducer, in a partially overlapping group of 11 patients (group B), it was measured with a fluid-filled system. For reference cardiac output we used the proven method of four uncorrected thermodilution estimates equally spread over the ventilatory cycle. RESULTS: A total of 208 cardiac output estimates was obtained in group A, and 228 in group B. In group B, 48 estimates could not be corrected because of insufficient pulmonary artery pressure waveform quality from the fluid-filled system. Individual uncorrected Stewart-Hamilton estimates showed a large variability with respect to their mean. In group A, mean cardiac output was 5.01 l/min with a standard deviation of 0.53 l/min, or 10.6%. After flow correction, this scatter decreased to 5.0% (P < 0.0001). With no bias, the corresponding limits of agreement decreased from +/- 1.06 to +/- 0.5 l/min after flow correction. In group B, the scatter decreased similarly and the limits of agreement also became +/- 0.5 l/min after flow correction. CONCLUSION: It was concluded that a single thermodilution cardiac output estimate using the flow-corrected equation is clinically feasible. This is obtained at the cost of a more complex computation and an extra pressure measurement, which often is already available. With this technique it is possible to reduce the fluid load to the patient considerably.