2,535 research outputs found
Arsenic removal by a membrane hybrid filtration system
Arsenic is a toxic semi-metallic element that can be fatal to human health. Membrane filtration can remove a number of contaminants from water, including arsenic. Removal of arsenic by membrane filtration is highly dependent on the species of arsenic and the properties of the membrane. The performance of the nanofilter is better for removing As(V) than As(III). About 57% of As(III) and 81% of As(V) was removed from 500 mg/L arsenic solutions by nanofiltration (NTR729HF, Nitto Denko Corp., Japan) of 700 molecular weight (MW) cutoff. The removal efficiency of microfiltration (MF) was much lower than that of nanofiltration (NF) due to its larger pore size. By comparison only 37% of As(III) and 40% of As(V) were removed by microfiltration (PVA membrane, Pure-Envitech, Korea). However, the removal efficiency of microfiltration was increased dramatically when a small amount of nanoscale zero valent iron (nZVI) was added. The removal efficiency by MF increased up to 90% with As(V) and 84% with As(III) when an amount of 0.1 g/L of nZVI was added into the arsenic solution. Ā© 2008 Elsevier B.V. All rights reserved
Serially connected forward osmosis membrane elements of pressure-assisted forward osmosis-reverse osmosis hybrid system: Process performance and economic analysis
Ā© 2018 Elsevier B.V. Due to the improved dilution of draw streams, employing pressure-assisted forward osmosis (PAFO) to the hybrid system of forward osmosis (FO) followed by reverse osmosis (RO) for seawater desalination has been expected to reduce the overall economics. However, replacing FO with PAFO causes an additional energy cost in the seawater dilution step which inevitably leads to a question that PAFO-RO hybrid is truly an economically beneficial option. More importantly, though serial connection of FO elements improves the dilution of initial draw water, this economic benefit is also compensated with the additional membrane. To rationalize its overall performance and economic benefit, thorough performance and economic evaluations were conducted based on actual pilot-scale PAFO operations for serial connection of up to three 8040 FO elements. The results showed the FO-RO hybrid is not an economically feasible option unless a significant unit FO element cost cut-down is guaranteed. Meanwhile, PAFO-RO showed benefits with regards to target RO recovery and unit FO element cost, particularly when two FO elements are serially connected (SE2). It was found that PAFO-RO, indeed, has higher economic potential than FO-RO. A graphical overlapping method suggested in this work can help determine optimal serial configuration and operating conditions of PAFO-RO
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Socio-economic factors & citizensā practices, enabling Positive Energy Districts: round-table discussion on local energy transitions
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Socio-economic factors & citizensā practices, enabling Positive Energy Districts: advisory report on accelerating PED design
In this report, we investigate the issue of silo thinking in the development of Positive Energy Districts (PEDs) as testified by stakeholders and propose recommendations to overcome silo thinking to achieve better collaboration between and within stakeholder groups. Involving all relevant stakeholders is argued to be essential to effectively reach PEDs and to include vulnerable as well as often overlooked groups in the process (Sareen et al., 2022). However, silo thinking can prevent or hinder the collaboration between stakeholder groups and within a stakeholder group. Thus, we identify silo thinking and best practices to overcome them, from stakeholder interviews conducted as part of a separate report (Derkenbaeva et al., 2022). The analysis focuses on three types of silo thinking ā institutional silos, silos of representation, and administrative silos ā and how to overcome them. In addition to the best practices suggested by stakeholders, additional perspectives to overcome silo thinking are proposed by the authors of this report.
In interviews with stakeholders from Amsterdam, the Canary Islands, and Lisbon metropolitan area, the following issues of silo thinking are identified:
āŖ Institutional silos between citizens, who want to consume renewable, affordable, and community-based energy, and large companies, who are concerned with efficiency and profit
āŖ Silo of representation of citizens about the impossibility for businesses to come out of their profit-driven practices
āŖ Silo of representation about citizensā knowledge and willingness to participate in PEDs projects that make citizens feel less empowered to collaborate as an equal partner with the government or large businesses
āŖ Administrative silos that hinder the governmentās financial support of cross sectoral energy transition efforts such as housing retrofit projects
To overcome the identified silos, we recommend:
āŖ Structural change by the national government providing a legal framework and incentives for local government and companies to engage more with citizens and small businesses during the development of PEDs
āŖ The use of intermediary organizations that can facilitate communication and collaboration between government sectors and between stakeholders
āŖ Intergroup communication that allows citizens and small businesses to acquire more information and voice their demands, breaking from misrecognition and exclusion from such discussion as the development of PEDs
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Socioāeconomic factors and citizens' practices, enabling positive energy districts. Challenging 'silo thinking' for promoting PEDs
Executive Summary:
Collaboration between disciplines, sectors, institutions, and communities is essential for the successful planning and implementation of Positive energy districts (PEDs). However, silo thinking, defined in this document as the disregard of other groupsā viewpoints or interests, poses a barrier to effective collaboration. Based on a review of existing literature, multiple factors were identified that could potentially cause silo thinking in the context of PEDs. First, differences in beliefs and ideologies create silos across disciplines, stakeholders, and communities. Divergent goals across sectors hinder collaboration between departments of the government. Misconceptions and prejudice present barriers in communication between citizens and the government. Furthermore, a lack of consideration for local culture and history may prevent collaboration between different cities and obstruct governments from engaging local innovations. Silos between disciplines and sectors are difficult to overcome because the long tradition of these silos means people are inexperienced in coordination across the boundaries of their own discipline or sector, making coordination more costly.
In the planning and implementation of PEDs, systems thinking is a key change in mindset that allows problem solving in the presence of interdependencies between different groups. Systems thinking can be incorporated in education, midāmanagement training, and work culture. Experts, researchers, and higherālevel governance institutions can incorporate this type of holistic thinking to take a nexus approach or multidisciplinary approach in policy framing. As useful as it may be, in practical application, the systems approach can be obstructed by existing boundaries of organisations. Thus, the government also takes a primary role in facilitating coordination of different entities, by devising coordination bodies within the government and channels of communication with the public, as well as encouraging networks among businesses. Finally, citizens and grassroot organisations can be empowered by these government efforts and more actively engage in actions for PEDs
A decision support tool for health service re-design
Many of the outpatient services are currently only available in hospitals, however there are plans to provide some of these services alongside with General Practitioners. Consequently, General Practitioners could soon be based at polyclinics. These changes have caused a number of concerns to Hounslow Primary Care Trust (PCT). For example, which of the outpatient services are to be shifted from the hospital to the polyclinic? What are the current and expected future demands for these services? To tackle some of these concerns, the first phase of this project explores the set of specialties that are frequently visited in a sequence (using sequential association rules). The second phase develops an Excel based spreadsheet tool to compute the current and expected future demands for the selected specialties. From the sequential association rule algorithm, endocrinology and ophthalmology were found to be highly associated (i.e. frequently visited in a sequence), which means that these two specialties could easily be shifted from the hospital environment to the polyclinic. We illustrated the Excel based spreadsheet tool for endocrinology and ophthalmology, however, the model is generic enough to cope with other specialties, provided that the data are available
The core Planar Cell Polarity gene, Vangl2, maintains apical-basal organisation of the corneal epithelium
This work was performed under Biotechnology and Biological Sciences Research Council (BBSRC) research grant BB/J015237/1 to JMC. DAP was funded by an Anatomical Society PhD Studentship whose support is gratefully acknowledged. ASF was funded by a BBSRC DTG PhD Studentship. We thank staff at the Medical Research Facility and Aberdeen Microscopy Services for technical assistance.Peer reviewedPostprin
Static and vibration analysis of functionally graded beams using refined shear deformation theory
Static and vibration analysis of functionally graded beams using refined shear deformation theory is presented. The developed theory, which does not require shear correction factor, accounts for shear deformation effect and coupling coming from the material anisotropy. Governing equations of motion are derived from the Hamilton's principle. The resulting coupling is referred to as triply coupled axial-flexural response. A two-noded Hermite-cubic element with five degree-of-freedom per node is developed to solve the problem. Numerical results are obtained for functionally graded beams with simply-supported, cantilever-free and clamped-clamped boundary conditions to investigate effects of the power-law exponent and modulus ratio on the displacements, natural frequencies and corresponding mode shapes
A cell cycle-coordinated Polymerase II transcription compartment encompasses gene expression before global genome activation
Ā© 2019, The Author(s). Most metazoan embryos commence development with rapid, transcriptionally silent cell divisions, with genome activation delayed until the mid-blastula transition (MBT). However, a set of genes escapes global repression and gets activated before MBT. Here we describe the formation and the spatio-temporal dynamics of a pair of distinct transcription compartments, which encompasses the earliest gene expression in zebrafish. 4D imaging of pri-miR430 and zinc-finger-gene activities by a novel, native transcription imaging approach reveals transcriptional sharing of nuclear compartments, which are regulated by homologous chromosome organisation. These compartments carry the majority of nascent-RNAs and active Polymerase II, are chromatin-depleted and represent the main sites of detectable transcription before MBT. Transcription occurs during the S-phase of increasingly permissive cleavage cycles. It is proposed, that the transcription compartment is part of the regulatory architecture of embryonic nuclei and offers a transcriptionally competent environment to facilitate early escape from repression before global genome activation
Where to from here? A quality improvement project investigating burns treatment and rehabilitation practices in India
Abstract Objective To describe the capacity of the Indian healthcare system in providing appropriate and effective burns treatment and rehabilitation services. Results Health professionals involved in burns treatment or rehabilitation at seven hospitals from four states in India were invited to participate in consultative meetings. Existing treatment and rehabilitation strategies, barriers and enablers to patient flow across the continuum of care and details on inpatient and outpatient rehabilitation were discussed during the meetings. Seventeen health professionals from various clinical backgrounds were involved in the consultation process. Key themes highlighted (a) a lack of awareness on burn first aid at the community level, (b) a lack of human resource to treat burn injuries in hospital settings, (c) a gap in burn care training for medical staff, (d) poor hospital infrastructure and (e) a variation in treatment practices and rehabilitation services available between hospitals. A number of opportunities exist to improve burns treatment and rehabilitation in India. Improvements would most effectively be achieved through promoting multidisciplinary care across a number of facilities and service providers. Further research is required to develop context-specific burn care models, determining how these can be integrated into the Indian healthcare system
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