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At least 127 records · Page 7

Low frequency vibrational stirring - A new method for rapidly mixing solutions and melts during growth

A new method for rapidly stirring liquids has been developed which may be useful in crystal growth applications. The method involves the introduction of orthogonally coupled low frequency vibrations to fluids contained in cylindrical crucibles. A mathematical model has been developed to describe the influence of this vibrational stirring method on fluid flow. The optimum sloshing frequencies calculated for a specific system geometry were very close to those observed experimentally. A systematic study of the fluid flow induced by the vibrational motion was carried out at room temperature using aqueous solutions containing glycerine. Preliminary experiments were carried out to study the effect of vibrational stirring on interface shape and position during the Bridgman growth of CsCdCl3, a model system.

Liu, W.-S.↗

Current Trends in the Treatment of Hepatocellular Carcinoma with Transarterial Embolization: Variability in Technical Aspects

Purpose: While transarterial chemoembolization (TACE) is a mainstay of treatment for unresectable hepatocellular carcinomas (HCCs), technical aspects have varied considerably in the literature. These variations lead to heterogeneity and make meaningful comparisons between articles difficult. The goal of this survey was to report international embolization practices for the treatment of HCC in an effort to understand current treatment strategies as a first step toward technique standardization. Materials and Methods: An anonymous 18 question online survey, evaluating technical aspects of TACE, was distributed via e-mail to practicing members of the five largest interventional radiology societies in Chinese and English. A total of 1160 responses were obtained from 62 countries. Results: Between regions, there were significant statistical differences in nearly all responses, including the amount of ethiodol oil used for cTACE (p = < 0.001). Practitioners most commonly used greater than 7.5 ml of ethiodol oil (240/506, 47.4%) and most did not utilize a specific mixing method (249/505, 49.3%). Particles utilized varied by geographical region (p = < 0.001), spherical embolic particles were slightly favored (363/757, 47.9%), followed closely by gelatin-based or sponge particles (279/680, 36.8%). Gelfoam was used almost exclusively in Japan and Korea (79/82 responses). LC/DC beads were the most commonly used drug-eluting bead (DEB) (450/742, 60.6%), with the most common size of DEB being 100–300 μm (354/690, 51.3%, p = 0.07). Conclusion: Technical aspects of transarterial embolization for HCC vary significantly by geographical location.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Unified Geometric Multigrid Algorithm for Hybridized High-Order Finite Element Methods

In this paper, we consider a standard elliptic partial differential equation and propose a geometric multigrid algorithm based on Dirichlet-to-Neumann (DtN) maps for hybridized high-order finite element methods. The proposed unified approach is applicable to any locally conservative hybridized finite element method including multinumerics with different hybridized methods in different parts of the domain. For these methods, the linear system involves only the unknowns residing on the mesh skeleton, and constructing intergrid transfer operators is therefore not trivial. The key to our geometric multigrid algorithm is the physics-based energy-preserving intergrid transfer operators which depend only on the fine scale DtN maps. Thanks to these operators, we completely avoid upscaling of parameters and no information regarding subgrid physics is explicitly required on coarse meshes. Moreover, our algorithm is agglomeration-based and can straightforwardly handle unstructured meshes. We perform extensive numerical studies with hybridized mixed methods, hybridized discontinuous Galerkin methods, weak Galerkin methods, and hybridized versions of interior penalty discontinuous Galerkin methods on a range of elliptic problems including subsurface flow through highly heterogeneous porous media. We compare the performance of different smoothers and analyze the effect of stabilization parameters on the scalability of the multigrid algorithm.

97 MATHEMATICS AND COMPUTING↗

Flow-Assisted Selective Mineral Extraction from Seawater

The sustainable production of critical materials from natural sources requires a paradigm shift away from currently used resource-intensive processes. In this paper, we report a single-step, laminar co-flow method (LCM) that leverages non-equilibrium conditions to selectively extract pure Mg(OH) 2 from natural seawater. Conventional seawater-based Mg extraction involves adding individual or a combination of precipitants to obtain Mg(OH) 2 , but the co-existence of Ca 2+ unavoidably results in CaCO 3 impurities requiring additional purification steps. Here we show that the non-equilibrium conditions in LCM achieved using a microfluidics device and by simply co-injecting a NaOH solution with seawater can result in improved selectivity for Mg(OH) 2 unlike in conventional bulk mixing method. The resulting precipitates are characterized for composition and the process yield and purity are optimized through systematic variations of the reaction time and the concentration of NaOH. This is the first demonstration of LCM for selective separation, and as a one-step process that does not rely on novel sorbents, membranes, or external stimuli, it is easy to scale-up. LCM has the potential to be broadly relevant to selective separations from complex feed streams and diverse chemistries—enabling more sustainable materials extraction and processing.

54 ENVIRONMENTAL SCIENCES↗

How deep to dig: effects of web-scraping search depth on hyperlink network analysis of environmental stewardship organizations

Abstract Social network analysis (SNA) tools and concepts are essential for addressing many environmental management and sustainability issues. One method to gather SNA data is to scrape them from environmental organizations’ websites. Web-based research can provide important opportunities to understand environmental governance and policy networks while potentially reducing costs and time when compared to traditional survey and interview methods. A key parameter is ‘search depth,’ i.e., how many connected pages within a website to search for information. Existing research uses a variety of depths and no best practices exist, undermining research quality and case study comparability. We therefore analyze how search depth affects SNA data collection among environmental organizations, if results vary when organizations have different objectives, and how search depth affects social network structure. We find that scraping to a depth of three captures the majority of relevant network data regardless of an organization’s focus. Stakeholder identification (i.e., who is in the network) may require less scraping, but this might under-represent network structure (i.e., who is connected). We also discuss how scraping web-pages of local programs of larger organizations may lead to uncertain results and how our work can combine with mixed methods approaches.

Sayles, Jesse S. (ORCID:0000000218378920)↗

Mineral Scale Prevention on Electrically Conducting Membrane Distillation Membranes Using Induced Electrophoretic Mixing

The growth of mineral crystals on surfaces is a challenge across multiple industrial processes. Membrane-based desalination processes, in particular, are plagued by crystal growth (known as scaling), which restricts the flow of water through the membrane, can cause membrane wetting in membrane distillation, and can lead to the physical destruction of the membrane material. Scaling occurs when supersaturated conditions develop along the membrane surface due to the passage of water through the membrane, a process known as concentration polarization. To reduce scaling, concentration polarization is minimized by encouraging turbulent conditions and by reducing the amount of water recovered from the saline feed. In addition, antiscaling chemicals can be used to reduce the availability of cations. Here, we report on an energy-efficient electrophoretic mixing method capable of nearly eliminating CaSO4 and silicate scaling on electrically conducting membrane distillation (ECMD) membranes. The ECMD membrane material is composed of a percolating layer of carbon nanotubes deposited on porous polypropylene support and cross-linked by poly(vinyl alcohol). The application of low alternating potentials (2 Vpp,1Hz) had a dramatic impact on scale formation, with the impact highly dependent on the frequency of the applied signal, and in the case of silicate, on the pH of the solution.

54 ENVIRONMENTAL SCIENCES↗

Fabrication of CeO2/PANI composites for high energy density supercapacitors

Highlights: • Fabrication of CeO{sub 2}/PANI composite was successfully prepared using easy solution mixing method. • Combinational approaches of rare earth oxides with conducting polymer composites posses’ excellent pseudocapacitive nature. • Superior specific capacitance, rate capacitance and cyclic stability. • Outstanding performance of asymmetric and symmetric devices. - Abstract: Combinational approaches of rare earth oxides with conducting polymer composites have gained vast attention in supercapacitor field due to the outstanding pseudocapacitive property. Here we detail the redox reaction based on CeO{sub 2}/polyaniline nanostructure to grasp the superior electrochemical nature of the composite. The CeO{sub 2}/polymer nanostructure showed the improved specific capacitance of 1452 F g{sup −1} at 2 A g{sup −1} when compared to pristine CeO{sub 2} (927 F g{sup −1} at 2 A g{sup −1}). The composite also maintains excellent rate capacitance (875 F g{sup −1} at 10 A g{sup −1}) and good cyclic stability upto 1500 cycles at high current density of 20 A g{sup −1}. Symmetric and asymmetric supercapacitor devices were fabricated using CeO{sub 2}/ PANI as an electrode. Moreover, the asymmetric supercapacitor possesses excellent specific capacity (256 F g{sup −1} at 2 mV s{sup −1}) with high energy density (75 Whkg{sup −1}) and high power density (566 Wkg{sup −1}). These results suggest a potential usefulness of CeO{sub 2}/ PANI composite exploit as an efficient electrode for supercapacitor applications.

36 MATERIALS SCIENCE↗

“I Would Purposely Try to Keep them Separated”: Language Ideologies, Language Policy, and Beliefs about Emergent Bilinguals in Career and Technical Education

Abstract In the policy context of college and career readiness, career and technical education (CTE) is growing in popularity, especially for students who are underserved in academic high school programs. While CTE has shown promise for some students, very little research exists on its potential for emergent bilingual students (EBs). Thus, building on research of deficit perceptions of EBs and language ideologies (LIs), this study examines how LIs and deficit perspectives are reproduced in CTE contexts across Pennsylvania. Using a sequential mixed‐methods design, we found that, while CTE educators held generally positive attitudes toward EBs, they were influenced by monoglossic language ideology and standard language ideology. These LIs, along with other institutional factors, led educators to implement restrictive language policies within their classrooms. These implications serve to inform how, with a lack of clear language policy within CTE programs, teachers relied on their personal beliefs and reproduced deficit ideologies in the creation of classroom‐level policies.

Emerick, Mark R.↗

Interaction mechanism of transition metal phthalocyanines on transition metal nitride supports

Here, we investigated the electronic interactions between transition metal phthalocyanine (TMPc’s) on a refractory transition metal nitride support, specifically copper phthalocyanine (CuPc) on titanium nitride (TiN). X-ray Photoelectron Spectroscopy (XPS) results suggest a presence of a few nanometer native oxide layer on the surface of the TiN nanoparticles, which consists of TiN, TiO 2 , and Titanium oxynitrides (Ti x O y N z ). A TiNCuPc nanocomposite was synthesized via a simple mixing method due to the strong binding between CuPc and TiN confirmed by density functional theory (DFT) calculations. Both XPS data and DFT calculations revealed an electron transfer from TiN substrate to CuPc molecule. The nature of charge transfer is not influenced by the presence of an oxide layer on the surface of TiN. Substantial deviations are however found between photoelectron emission microscopy (PEEM) measured work function for TiN (4.68 eV) and theoretically calculated work function for pristine stoichiometric TiN (2.63 eV). This behavior is attributed to the presence of an oxide layer on the TiN surface. TiNCuPc composite system has a work function value between those of TiN and CuPc. Our studies open up an opportunity to apply a new class of materials based on transition metal phthalocyanine/transition metal nitride composites to catalysis and optoelectronic devices.

36 MATERIALS SCIENCE↗

Large-scale renewable energy project barriers: Environmental impact assessment streamlining efforts in Japan and the EU

Environmental Impact Assessment (EIA) procedures have been identified as a major barrier to renewable energy (RE) development with regards to large-scale projects (LS-RE). However EIA laws have also been neglected by many decision-makers who have been underestimating its impact on RE development and the stifling potential they possess. As a consequence, apart from acknowledging the shortcomings of the systems currently in place, few governments momentarily have concrete plans to reform their EIA laws. By looking at recent EIA streamlining efforts in two industrialized regions that underwent major transformations in their energy sectors, this paper attempts to assess how such reform efforts can act as a means to support the balancing of environmental protection and climate change mitigation with socio-economic challenges. Thereby this paper fills this intellectual void by identifying the strengths and weaknesses of the Japanese EIA law by contrasting it with the recently revised EIA Directive of the European Union (EU). This enables the identification of the regulatory provisions that impact RE development the most and the determination of how structured EIA law reforms would affect domestic RE project development. The main focus lies on the evaluation of regulatory streamlining efforts in the Japanese and EU contexts through the application of a mixed-methods approach, consisting of in-depth literary and legal reviews, followed by a comparative analysis and a series of semi-structured interviews. Highlighting several legal inconsistencies in combination with the views of EIA professionals, academics and law- and policymakers, allowed for a more comprehensive assessment of what streamlining elements of the reformed EU EIA Directive and the proposed Japanese EIA framework modifications could either promote or stifle further RE deployment. - Highlights: •Performs an in-depth review of EIA reforms in OECD territories •First paper to compare Japan and the European Union frameworks •Finds early-stage indicators for overall reform efficiency.

54 ENVIRONMENTAL SCIENCES↗

The attractive concept of simplicity in environmental impact assessment: Perceptions of outcomes in southeastern Brazil

Pressures are mounting for the simplification of environmental impact assessment (EIA). This phenomenon is drawing increasing scholarly attention, but studies have not gone far beyond speculating what could happen as a result of recently implemented or proposed regulatory changes. This paper takes a more longitudinal look at simplified EIAs. The main objective was to analyze the perceived outcomes of a number of simplified EIA processes, using Brazil as the empirical context. More specifically, this paper aimed at understanding: 1) how simplified EIAs have been conceptualized and implemented in southeastern Brazil; and 2) how developers and civil servants in that region perceive the outcomes of simplified EIAs. This study adopted a sequential mixed method research approach. Data was collected through literature reviews, 261 telephone-based interviews and 10 face-to-face interviews. Degrees of EIA simplification can vary significantly within and across jurisdictions. In any case, simplification is often framed as a win-win solution to EIA ineffectiveness, through which regulatory and procedural changes are made to ease the process, while, at the same time, maintaining or providing better environmental protection. This approach is more frequently applied to potentially low-impact processes. Chi-square tests of the data collected through telephone interviews in the Brazilian state of Minas Gerais indicated that developers tend to perceive EIA processes as difficult and slow regardless of how simplified it is. Most civil servants, who were directly involved in the implementation of simplified EIAs in state environmental agencies, argued that simplified EIAs are driven mostly by environmental agencies, as these institutions have long been unable to cope with an ever-increasing load of license applications. Policy outcomes of simplified EIAs in the territory are not sufficiently monitored by state agencies. Civil servants revealed concerns about the potential long term effects of EIA simplification on the ground, as they have had limited resources for audits and inspections. - Highlights: •Simplified EIA is conceptualized. •We analyze how simplified EIA is implemented and perceived in Brazil. •Developers perceived EIA as difficult and slow regardless of how simplified it was. •State agencies' low institutional capacity is a key driver of simplification. •Policy outcomes of simplified EIAs in the territory are not monitored.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Enabling high rate charge and discharge capability, low internal resistance, and excellent cycleability for Li-ion batteries utilizing graphene additives

A liquid-phase mixing method is adopted to uniformly disperse the graphene nanosheets onto LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode for high-performance Li-ion batteries (LIBs). The electrochemical performance was characterized using a full pouch cells with state-of-the-art electrode areal loading (compared to half coin cells). The addition of graphene sheets (i.e., only 1 wt%) significantly improves the high rate capability for charging and discharging operation. For example, 6 times improvement in 5 C charging was achieved providing further insights in enabling extreme fast charging for LIBs. Other benefits include longer cycleability, lower internal resistance, and higher lithium ion diffusion coefficient, demonstrated by charge-discharge cycling tests and electrochemical impedance spectroscopy. Higher capacity retention of 88.2% and decreased internal resistance of ~0.9 Ω are observed after 400 cycles. The diffusion coefficient of Li ions is 6.49 × 10 -8 cm 2 s -1 when charged to 4.2 V, which is approximately 1.37 times higher compared to the configuration with no graphene sheet (4.74 × 10 -8 cm 2 s -1 ). To conclude, the improved performance is ascribed to a robust network among the active materials formed by graphene sheets, which serves as an extended current conductor and facilitates charge transfer, ionic reversibility, and ionic transportation.

25 ENERGY STORAGE↗

What to expect when you're expecting engagement: Delivering procedural justice in large-scale solar energy deployment

Community engagement in the planning process to build large-scale solar (LSS) projects can win local support and advance procedural justice. However, an understanding of community engagement in current LSS development is lacking. Using responses from a U.S. nationwide survey (n = 979) of residential neighbors living within 3 miles (4.8 km) of completed LSS projects (i.e. “solar neighbors”) and project details from the U.S. Large-Scale Solar Photovoltaic Database (USPVDB), this study seeks to answer the following questions: How are solar neighbors' perceptions of community engagement associated with their attitudes toward their LSS projects? How do solar neighbors' perceptions of community engagement compare to their expectations? And, how do neighbors explain what they perceived about the planning process? We answer these questions using mixed methods, including regression modeling, a new gap analysis technique, and qualitative coding. We find that higher perceived engagement is associated with more positive attitudes toward the project, even when controlling for respondents who acted in opposition. Supporters and opponents alike expect more engagement than they perceived and information about projects both before construction and after operation is lacking. Awareness and engagement expectations increase at certain project size and proximity thresholds. However, most neighbors expect the public to offer input during engagement, but not make decisions. We contextualize these findings with explanatory comments from respondents.

14 SOLAR ENERGY↗

Passive and active peer effects in the spatial diffusion of residential solar panels: A case study of the Las Vegas Valley

This research analyzes the role of peer influences on the adoption of residential rooftop solar photovoltaic panels (PV) within the context of the Diffusion of Innovation Theory. PV literature indicates that adopters are influenced by word of mouth (WOM) information exchange with peers, i.e., active peer effects, while other studies suggest that living near households with visible rooftop PV installations influences adoption, i.e., passive peer effects. We bridge the gap in this literature by conducting a mixed methods analysis. We develop and administer a survey to Las Vegas Valley (LVV) residents to identify current and potential PV adopters' perceptions of peer-effects and consumer intention variables. We conduct a spatial analysis of Google's Project Sunroof data to identify LVV neighborhoods in the later stages of the PV diffusion process, i.e., those with the highest PV adoption rates. Key results show that current PV adopters living in early diffusion areas report significantly higher active and passive peer effects compared to adopters in later diffusion areas. Potential adopters in later diffusion areas report higher passive peer effects than those in early diffusion areas. Overall, because LVV has a low PV adoption rate (<3%), short term strategies aimed at increasing PV adoption should emphasize WOM active peer effects. Here, we caution against long-term green marketing strategies focusing solely on peer-effects as the PV market matures.

14 SOLAR ENERGY↗

Use of Online Media for Professional Development Amongst Medical Radiation Practitioners in Australia and Canada

Online media allows access to professional development (PD) regardless of geographical location and has the potential to provide equitable, immediate and quality PD. Online media includes online information and social media. The purpose of this mixed methods research study was to investigate the perceptions and use of online media for PD amongst medical radiation practitioners within Australia and Canada. An online survey was circulated to members of the Canadian Association of Medical Radiation Technologists (CAMRT) and the Australian Society of Medical Imaging and Radiation Therapy (ASMIRT). The survey collected data within three domains: current use, satisfaction of use, and future use. A four point Likert scale was used for both satisfaction with the online platform and frequency of use. Two hundred and thirty-nine responses were collected. Results indicated that the online mechanisms most frequently used by respondents for PD were Google, self-directed learning, and intranet. A correlating degree of satisfaction was indicated with the use of these platforms. The least used online media for PD were social media platforms including health related blogs, LinkedIn, Twitter, health related and professional applications, Facebook, and online journal clubs. Online media is well suited to PD for medical radiation practitioners. The platforms that are preferred offer speed and ease of access regardless of geographical location or occupation. Whilst inherent risks and instances of unprofessional online behaviour are acknowledged, Australian and Canadian practitioners are keen to learn what social media PD opportunities exist. Findings indicate that radiation therapists are more receptive to explore new social media platforms and tools than are radiographers. There is an opportunity to incorporate formal PD for medical radiation practitioners within recognised social media platforms.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Insights into activators on biomass-derived carbon-based composites for electrochemical energy storage

Biomass-derived carbon materials are now an essential source of carbon electrodes for high-performance supercapacitors due to their cost-effectiveness and abundant heteroatom self-doping properties. When preparing porous carbon materials from biomass for supercapacitor use, the use of activators can significantly increase the specific surface area of carbon materials, enhance pore structures, introduce more heteroatoms, promote the generation of various functional groups, and play a crucial role in the capacitance performance of biomass-derived carbon materials. However, the role of activators during the activation process has been overlooked in previous work focused on improving supercapacitor capacitance performance. In addition, there is a lack of comprehensive reviews summarizing the role of activators. Therefore, this work classifies the types of activators, discusses their activation mechanisms, operability, economy, and environmental friendliness, and proposes future development directions for activators. The main mixing methods of activators and carbon materials are also demonstrated, highlighting the advantages and disadvantages of each method. In conclusion, this work could provide valuable insights for the development of activators for high-performance supercapacitors.

25 ENERGY STORAGE↗

Intervening alcohol marketing to reduce harmful alcohol use and lessons learned from the theory of changes: Case studies in Thailand

Objectives Globally, the burden of disease caused by alcohol use has been steadily increasing, including in Thailand. In this study, we aim to test the effectiveness of Anderson et al.‘s suggested three approaches to change the collective social norms, which comprise of: (1) providing information and an understanding about alcohol use behaviour, its causes and distribution; (2) focusing strategies on groups rather than individuals; and (3) strengthening supportive laws, regulations and approaches. Study design We employed a mixed-methods approach. Evidence was gathered from literature review and in-depth interviews with key individuals who are responsible for community-based interventions to alcohol marketing strategies in Thailand. Methods We chose to focus on two case studies in Nan and Surin provinces, where hospital-based longitudinal data (8 years) were available. Changes in casualties related to the harmful use of alcohol, resulting from interactions between community-based interventions and alcohol marketing during the time of annual festivals were investigated. We employed the theory of change (ToC) defined by Vogel to guide the data collection and analysis. We reviewed literature from online databases and grey literature to generate causal-loop diagrams. Results We created a causal-loop diagram to describe the complexity of harmful alcohol use, its related factors, context, interventions and outcomes. Over the decade between 2006 and 2015, community-based strategies led to a substantial reduction of casualties (initially a 50% reduction, rising to an 80–90% reduction by the end of the study period) during the time of the festivals. Conclusions The reduction in injuries and fatalities could be a result of the concerted actions, including legal sanctions of alcohol beverage sales and advertisement, and public education to raise awareness and impart knowledge of the harmful use of alcohol. The actions were organised by a coalition of civil society, health professionals, public authorities and community leaders using hospital-based data on the adverse effects of harmful alcohol use to mobilise political support at the provincial level. The availability of long-term financial support as a catalytic source of funds and the presence of a comprehensive alcohol control act enabled framing and mobilisation of local resources and political support.

60 APPLIED LIFE SCIENCES↗

A conceptual framework for negotiating public involvement in municipal waste management decision-making in the UK

Highlights: • A review of public involvement in waste management decision-making was undertaken. • Public involvement seen as necessary to create stronger foundations for decisions. • The mode and level of public involvement explored in different decision contexts. • Public involvement can be negotiated based on the technological and social context. • Early public involvement favoured where issues are contentious or uncertain. - Abstract: The technical expertise that politicians relied on in the past to produce cost-effective and environmentally sound solutions no longer provides sufficient justification to approve waste facilities. Local authorities need to find more effective ways to involve stakeholders and communities in decision-making since public acceptance of municipal waste facilities is integral to delivering effective waste strategies. This paper presents findings from a research project that explored attitudes towards greater levels of public involvement in UK waste management decision-making. The study addressed questions of perception, interests, the decision context, the means of engagement and the necessary resources and capacity for adopting a participatory decision process. Adopting a mixed methods approach, the research produced an empirical framework for negotiating the mode and level of public involvement in waste management decision-making. The framework captures and builds on theories of public involvement and the experiences of practitioners, and offers guidance for integrating analysis and deliberation with public groups in different waste management decision contexts. Principles in the framework operate on the premise that the decision about ‘more’ and ‘better’ forms of public involvement can be negotiated, based on the nature of the waste problem and wider social context of decision-making. The collection of opinions from the wide range of stakeholders involved in the study has produced new insights for the design of public engagement processes that are context-dependent and ‘fit-for-purpose’; these suggest a need for greater inclusivity in the case of contentious technologies and high levels of uncertainty regarding decision outcomes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗