bluuebunny/crossref_metadata_2025 huggingface dataset:
Planning for Water Reclamation IN A SEMICONDUCTOR FABRICATION FACILITY
Authors: Chasey Allan D. , Striffler Edward A.
Published: February 2018

Reclaiming process wastewater is of increasing importance to the microelectronics industry, given escalating factory costs; increased burdens on municipal infrastructure; compliance issues; the limited resources available to sustain a young, fast‐changing industry; and the need to deliver new, expanded, and reequipped semiconductor factories faster. Water reclamation offers a viable means of providing for the future water needs of the microelectronics industry while reducing demands on the public water system. Water reclamation has great potential for implementation in new and existing factory design, can be accomplished using available technologies, and is cost‐effective when the operational savings from reduced consumption, discharge reduction, and discharge quality requirements are taken into consideration. This article describes the development of a water reclamation plan for a large‐scale production facility and includes system descriptions, diagrams, and flow analyses.
Removing oils FROM WATER with organoclays
Authors: Alther George R.
Published: February 2018

Organically modified clays have long been used by industry to remove oil from water. A study was undertaken to verify results from real‐world applications and develop a better understanding of the chemical conditions under which organoclays are most effective. Systematic testing was conducted on some 50 oils, including mineral oils, vegetable oils, animal fats, fish oils, and synthetic oils. In addition, the adsorption capacity of activated carbon was tested in order to compare the effectiveness of the two media. Tests also investigated the removal capacity of organoclays for various surfactants as well as the influence such surfactants exert on the removal efficiency of the organoclays. Results showed organoclays are more effective than activated carbon in removing oil from water and cationic organoclays are superior to nonionic organoclays for some removal applications.
Management of Nonrevenue Water in four cities of Bangladesh
Authors: Chowdhury M. A. I. , Ahmed M.F. , Gaffar M.A.
Published: February 2018

Nonrevenue water (NRW), mainly caused from leaking pipes and other sources of wasted water, is a concern to water utilities around the world. Some countries have very low NRW levels, such as the Netherlands with just 5% of its water lost to NRW. Other countries, and very often developing countries, have NRW levels many times that rate, some more than 60%. Most countries experience NRW levels of between 20 and 30%. In recent years, Bangladesh has faced severe water system leakage not only in its capital and large cities but also in medium‐sized cities. Four medium‐sized cities, Kushtia, Sylhet, Cox's Bazar, and Pabna, estimated their respective NRW in 1992‐93 as 22, 40, 42, and 52%. This water loss affects about 1 million people. To reduce the high rate of NRW to an acceptable level in medium‐sized cities throughout the country, the Local Government Engineering Department conducted a leakage control study in the four subject cities to examine the currently deteriorating situation of the existing water supply systems, including unacceptable leakage levels. The study provided new methods and approaches to upgrade the water distribution networks by controlling leakage and implementing remedial measures to bring NRW down to a satisfactory level.
Tailored rates
Authors: Teodoro Manuel P.
Published: February 2018

Public water utilities formulate service rates to accomplish several goals. Three common rate‐making goals are: stability, or the ability to generate revenue reliably; equity, or the degree to which rates reflect customers' cost of service; and, conservation, or the efficient use of natural resources. In many cases, utilities that have tried to improve the equity and/or conservation qualities of their rates have risked increased revenue volatility. Part of the answer to this dilemma might be fixed monthly rates tailored to reflect individual customers' usage patterns. By adopting cost‐of‐service fixed rates for each individual customer, rather than classes of customers, utilities can achieve greater customer equity, enjoy a stable revenue base, and send more accurate price signals to promote conservation.
Perchlorate reduction in a HYDROGEN‐BASED MEMBRANE–BIOFILM REACTOR
Authors: Nerenberg Robert , Rittmann Bruce E. , Najm Issam
Published: February 2018

The perchlorate anion (ClO4–) has been found in potentially harmful concentrations in numerous water sources. Because perchlorate is not removed by conventional water treatment processes, new treatment processes are needed. Biological perchlorate reduction is a promising alternative. The authors investigated a hydrogen‐oxidizing hollow‐fiber membrane–biofilm reactor system for perchlorate removal. Hydrogen is an ideal electron donor for biological drinking water treatment because it presents no toxicity, is inexpensive, and is unlikely to persist as a source of biological instability in distributions systems. The reactor delivers hydrogen in an efficient and safe manner. Results showed that biological perchlorate reduction takes place concurrently with nitrate reduction, no specialized inoculation is required, and perchlorate can be removed to below the preliminary regulatory standards with no chemical addition other than hydrogen gas. The optimal pH is 8, and the accumulation of intermediates is unlikely. Full denitrification and pH control may be required for excellent perchlorate removal.
A novel ion exchange process for As removal
Authors: Kim Jaeshin , Benjamin Mark M. , Kwan Pierre , Chang Yujung
Published: February 2018

The major drawback to the use of ion exchange for removal of arsenate [As(V)] from potable water is that other ions, especially sulfate (SO4), compete with the As(V) for exchange sites, leading to early As breakthrough and As chromatographic peaks in the effluent. This article describes a novel approach for operating an ion exchange process in which an As(V)‐rich zone is semipermanently retained in the operating columns so that only SO4‐rich resin is regenerated. When the process was used in this study, essentially all the As(V) fed to the system was retained during treatment of >36, 000 bed volumes of influent. This study also investigated the use of calcium or barium chloride salts to precipitate calcium sulfate or barium sulfate from the brine and the subsequent reuse of the brine solution. Overall, results indicate that the combination of modified column operation and brine recovery can dramatically reduce the brine requirement for As treatment by ion exchange.
Effect of Distribution System Materials on bacterial regrowth
Authors: Camper Anne K. , Brastrup Kristin , Sandvig Anne , Clement Jonathan , Spencer Catherine , Capuzzi A.J.
Published: February 2018

To assess the interactions between pipe materials, organic carbon levels, and disinfectants, studies using annular reactors with ductile‐iron, polyvinyl chloride (PVC), epoxy, and cementlined coupons were carried out in the laboratory and at four field sites. Laboratory studies used biologically treated water with and without 0.2 mg/L residual free chlorine or monochloramine, in the presence or absence of 0.5 or 2.0 mg/L humic substances. In the lab studies, the type of disinfectant did not lead to significant differences in effluent and biofilm counts. Increases in carbon led to greater numbers of biofilm and effluent organisms, with the effect most pronounced on iron. Regardless of carbon level, PVC systems typically had the lowest numbers of bacteria, whereas iron had the highest. Cement and epoxy were intermediate. Depending on the site, field studies showed that iron had the highest number of bacteria or there was no difference in materials.
Formation of NDMA in Chloraminated Water Coagulated with DADMAC Cationic Polymer
Authors: Wilczak Andrzej , Assadi‐Rad Ardeshir , Lai H. Hubert , Hoover Linnea L. , Smith James F. , Berger Robert , Rodigari François , Beland John W. , Lazzelle Laura J. , Kincannon Eric G. , Baker Hursey , Heaney C. Tom
Published: February 2018

Cationic treatment polymer, diallyldimethylammonium chloride (DADMAC), was the only significant source of N‐nitrosodimethylamine (NDMA) precursors in tested waters at the East Bay Municipal Utility District. NDMA concentrations increased with higher cationic polymer doses and longer chloramine contact times. Recycled filter backwash supernatant was a significant source of NDMA precursors, possibly because of residual cationic polymer. Higher NDMA levels were formed with pre‐ammoniation or simultaneous addition of chlorine (Cl2) and ammonia (NH3), whereas free Cl2 contact time prior to chloramination resulted in lower NDMA concentrations with less dependence on polymer dose. NH3, nitrite, and nitrate did not form NDMA with DADMAC; chloramine was necessary to form significant levels of NDMA. NDMA concentrations in the chloraminated distribution system decreased when the cationic polymer doses at two treatment plants were decreased. The lowest concentrations of NDMA were observed in the service areas that received water that was coagulated at low polymer doses and did not contain recycled filter backwash water.
Recent Advances in Water‐conserving Plumbing Products
Authors:   The Nature Conservancy, McHale Jim
Published: February 2018

This article discusses how today's generation of water‐conserving plumbing products are completely re‐engineered to deliver conservation without compromise; however, there remains the issue of winning back the trust of end‐users, installers, and legislators. The article describes an effort to convince metropolitan Atlanta's 4 million residents to retrofit their bathrooms for water efficiency, including water‐efficiency testing to prove that high‐efficiency plumbing products carrying the U.S. Environmental Protection Agency's WaterSense® label and/or those tested by respected third party agencies can be trusted to save water.
Residential water use trends in North America
Authors: Rockaway Thomas D. , Coomes Paul A. , Rivard Joshua , Kornstein Barry
Published: February 2018

Many water utilities have noted that average residential water use has fallen even though the number of customer households continues to grow, a trend observed in many communities and not confined to water‐scarce regions. Several theoretical reasons have been advanced to explain these declining trends, including wetter weather, new water‐conserving appliances, changing demographics, and classification anomalies. Although declining water use is dependent on many factors and local conditions, a key reason appears to be the increased use of water‐conserving fixtures and appliances. To date, however, no definitive statement could be made as to the validity of these hypotheses or the amount each contributes to the observed decline in residential water use. This research assessed each component's contribution to decreasing water use by critically evaluating national, regional, and local data trends. The understanding of residential customer water use resulting from this study indicates that this declining trend is not a temporary condition. Water utilities should assess their own regional water use characteristics and appropriately adjust to the trend of reduced water sales to residential customers.
Reaping the Benefits of AMI: A Kansas City Case Study
Authors: Thiemann Rob , Haas Jay , Schlenger Don
Published: February 2018

This article discusses an effort by the Kansas City (Missouri) Water Services Department (KCWSD) to select and acquire an advanced metering infrastructure (AMI) system and to design and plan for the improvement of customer service operations using the data collected by the meter‐reading system. The article describes how KCWSD leveraged its AMI investment by redesigning selected business practices to take fullest advantage of the capabilities of its AMI system, especially in redesigning key billing and customer service policies and procedures based on the availability of daily meter reads.
Optimal transient network design: A multi‐objective approach
Authors: Jung Bong Seog , Boulos Paul F. , Altman Tom
Published: February 2018

The most advantageous way to formulate the design of a water distribution system under transient conditions is as a multi‐objective optimization problem. The first objective in such a design is a least‐cost optimization problem using pipe diameters as decision variables. The second objective is to minimize the likelihood of a damaging transient event. In this article, a new surge damage measure called surge damage potential factor is introduced. Evolutionary algorithms are applied to produce a set of Pareto‐optimal solutions in the search space of pipe cost and surge damage potential. The model was tested on the New York City tunnel system. Comparison of the proposed method with that of a conventional approach shows that the modifications of pipe size in the design process can result in an effective and inexpensive surge control strategy.
Defining Public Asset Management for Municipal Water Utilities
Authors: Baird Gregory M.
Published: February 2018

This article describes public asset management as incorporating the management of all things that are of value to a jurisdiction, its mission and purpose, and citizen's expectations. With 85% of U.S. water utilities owned or controlled by governments and municipalities, asset management for utilities falls under the larger umbrella of public asset management. The article focuses on geographic information system‐ (GIS‐) centric public asset management, which has a foundation that standardizes data and allows interoperability, providing users with the capability of reusing, coordinating, and sharing information in an efficient and effective manner. The article demonstrates how a GIS platform combined with the overall public asset management umbrella of both hard (physical) assets and soft assets helps remove the traditional silos of structured municipal functions.
Effect of water disinfection type on adverse fetal outcomes
Authors: Wright J. Michael , Rivera‐Núñez Zorimar
Published: February 2018

The authors found small increased risks of preterm delivery (PTD) for chlorinated surface water, chlorinated groundwater, chloraminated water, and all other types of disinfected drinking water (range = 1.09–1.20) compared with untreated groundwater. Similar odds ratios (range = 1.08–1.16) were detected for small‐for‐gestational‐age (SGA) measurements and exposure to chlorinated surface water, chloraminated water, and other water disinfectants. A reduction in mean birth weight for these three exposure groups (range = 29–V39 g) was also found. Small differences in mean birth weight (≤ 16 g) were detected among chlorinated surface water users (versus chloraminated surface water), but odds ratios for SGA and PTD were comparable. Although associations were detected for disinfected drinking water exposure categories relative to untreated groundwater, the data suggest that risk of adverse birth outcomes among consumers of different types of disinfected drinking water were comparable in this study population.
What's the Buzz About Ceramic Membranes?
Authors: Freeman Scott , Shorney‐Darby Holly
Published: February 2018

Despite higher capital costs, the water industry is buzzing about ceramic membranes because they offer many potential benefits. This article discusses the potential benefits that include the following: improved operability resulting from a more robust filtration material, simplified operations and maintenance (especially cleaning), essentially no need for membrane element repair, and longer service life compared with polymeric alternatives.
The effect of hydroxyapatite nanoparticles on adipogenic differentiation of human mesenchymal stem cells
Authors: Yang Xing , Li Yuanyuan , Huang Qianli , Liu Xujie , Zhang Ranran , Feng Qingling
Published: February 2018

Due to its excellent biocompatibility, nanosized hydroxyapatite (nHA) has drawn much attention for various applications in biomedical fields. There are growing concerns about its biosecurity; however, little is known about its effects on adipogenesis. In the present study, nHA with three different sizes were synthesized, and the in vitro effects of nHA on cell proliferation and adipogenic differentiation of human mesenchymal stem cells (hMSCs) were investigated. The results clearly show that nHA does not affect the cell viability, the lipids droplets formation, triglyceride (TG) synthesis, and the expression of adipogenic marker genes/proteins of hMSCs at concentrations lower than 50 μg/mL. It is concluded that the adipogenic differentiation potential of hMSCs is not affected by nHA at noncytotoxic concentrations. These will provide a reference for the applications of nHA in biomedical fields. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1822–1831, 2018.
Exploring acceptability of oral PrEP prior to implementation among female sex workers in South Africa
Authors: Eakle Robyn , Bourne Adam , Mbogua Judie , Mutanha Nyaradzo , Rees Helen
Published: February 2018

Introduction

Female sex workers (FSWs) are at high‐risk for HIV acquisition in South Africa, where the advent of new HIV prevention and treatment interventions represent the potential to significantly impact the epidemic. This paper focuses on aspects of PrEP acceptability as a new intervention within the context of a larger service delivery programme including the simultaneous rollout of early ART. This paper explores PrEP acceptability among the FGD participants as future potential users.

Methods

FGDs were conducted in two clinic‐based sites in Johannesburg and Pretoria. They aimed to explore community‐level, multi‐dimensional acceptability of PrEP within the context of imminent implementation alongside early ART in the TAPS Demonstration Project. Sex worker peer educators recruited participants from varying sex work locales. Facilitation was in English with adaptation by facilitators into local languages as needed. Transcripts were translated and transcribed into English. Thematic analysis was used to analyse the data.

Results

Four FGDs were conducted in each site for a total of eight FDGs and 69 participants. Demographics were largely similar across the sites. Overall, there was strong acceptability of PrEP among participants and positive anticipation for the imminent delivery of PrEP in the local sex worker clinics. Themes arising from the discussions exploring aspects of PrEP acceptability included: awareness and understanding of PrEP; PrEP motivations including choice, control, and vulnerability, managing PrEP risks and worries; and, de‐stigmatizing and empowering PrEP delivery. Participant discussions and recommendations highlighted the importance of developing clear education and messaging to accurately convey the concept of PrEP, and intervention integration into supportive and tailored services.

Conclusions

Through the course of these FGDs, PrEP became a positive and highly anticipated prevention option among the FSWs participants who endorsed implementation in their communities. Effective integration of PrEP into existing services will include comprehensive health programming where ART is also available, appropriate messaging, and support.
Proximity effect in transient analysis of radio base stations
Authors: Chen Hongcai , Du Yaping
Published: February 2018

This paper presents an equivalent circuit model for calculating fast transient current distribution in radio base station system. The new model takes account of both skin and proximity effects in the simulation and achieves a fast computation by using an efficient discretization scheme. The obtained circuit is synthesized using a time domain solver, PSpice. The proposed method is validated experimentally and is applied to evaluate the lightning current in a practical radio base station. A practical system with a 20‐m tower and 7 cables is analyzed. Various surge protective devices (SPD) are installed among cables in the simulation. Comparison among different configurations reveals that proximity effect will lead to uneven current distribution in cables. Outer‐located cables will carry more currents than others which should be paid more attention.
Monostatic imaging of an embedded object using a confocal algorithm
Authors: Chouiti Sidi Mohammed , Merad Lotfi , Meriah Sidi Mohammed , Derraz Foued , Raimundo Xavier
Published: February 2018

In this paper, we present simulation results of monostatic configuration for microwave imaging system by using confocal algorithm to detect and localize metallic bars inserted in a concrete pillar. An ultra‐wideband antenna has been used. The dielectric property values of the model were chosen near those of the realities. However, we have changed the permittivity of the concrete pillar to study the effectiveness of the algorithm despite the introduction of different kind of concrete. Successful detection and localization of different shapes and positions of metallic bars of diameter as small as 4 mm are presented. The efficacy of the proposed algorithm was also demonstrated by adding noise to the backscattered signals before creating the image.
In vitro evaluation of controlled‐release 14% doxycycline gel for decontamination of machined and sandblasted acid‐etched implants
Authors: Patianna Giuseppe , Valente Nicola Alberto , D'Addona Antonio , Andreana Sebastiano
Published: February 2018

Background

Peri‐implant infections are associated with the establishment and maturation of a bacterial biofilm characterized by a predominance of Gram‐negative fusiform anaerobic species. The decontamination of implant surfaces is then crucial for a successful peri‐implant therapy.

Methods

Twenty‐one smooth and 21 rough implants, divided into four groups according to surface and treatment modality, were contaminated with Streptococcus sanguinis and then placed in an incubator with the atmosphere of 5% CO2 at 37°C for 24 hours to allow the bacteria to grow. After 24 hours, the test groups were treated with controlled release 14% doxycycline gel injecting the gel circumferentially over the surface of the implant for 3 minutes, while the control groups were irrigated with sterile saline for 1 minute. The implants were then vortexed into triptych soy broth to allow the bacteria to detach from the surface, diluted 1:100 and plated. Colony forming units (CFU) were counted 48 hours after incubation.

Results

The use of a 14% doxycycline gel minimized CFU counts compared to control groups, with the difference being statistically significant (P < 0.05). The reduction of CFUs in the smooth test group is more marked than in the rough test group, but the difference doesn't reach statistically significance (P = 0.215).

Conclusions

The use of 14% doxycycline gel in implant surface decontamination was efficacious in this in‐vitro study. Adjunctive use of locally delivered 14% doxycycline gel might be a viable option in the management of peri‐implantitis and peri‐implant mucositis considering its efficacy in reducing bacterial colonization.
Effects of d‐valine on periodontal or peri‐implant pathogens: Porphyromonas gingivalis biofilm
Authors: Qi Hua , Li Baosheng , Wang Heling , Cai Qing , Quan Xu , Cui Yunxia , Meng Weiyan
Published: February 2018

Background

When presented with a surface or an interface, bacteria often grow as biofilms in which cells are held together by an extracellular matrix. Biofilm formation on implants is an initiating factor for their failure. Porphyromonas gingivalis is the primary etiologic bacteria of initiation and progression of periodontal disease. This microorganism is also the risk factor of many systemic diseases, such as cardiovascular disease, diabetes, and pulmonary infection. To date, no medication that can remove such biofilm has been accepted for clinical use. D‐valine (D‐val) can reportedly inhibit the formation of biofilm and/or trigger the scattering of mature biofilm. Accordingly, this study investigated the effects of d‐val on single‐species P. gingivalis biofilms in vitro.

Methods

P. gingivalis grown in brain heart infusion culture with or without d‐val was inoculated in 24‐ or 96‐well plates. After incubation for 72 hours, biomass via crystal violet staining, extracellular polysaccharide production by biofilms, and scanning electron microscopy (SEM) were used to determine the d‐val concentration that can effectively prevent P. gingivalis biofilm formation.

Results

Experimental results showed that d‐val effectively inhibited biofilm formation at concentrations ≥50 mM (mMol/L), and that d‐val inhibition increased with increased concentration. Moreover, at high concentrations, the bacterial form changed from the normal baseball form into a rodlike shape. d‐val also notably affected extracellular polysaccharide production by P. gingivalis.

Conclusions

d‐val can inhibit P. gingivalis biofilm formation, and high concentrations can affect bacterial morphology.
Research priorities for managing invasive wild pigs in North America
Authors: Beasley James C. , Ditchkoff Stephen S. , Mayer John J. , Smith Mark D. , Vercauteren Kurt C.
Published: February 2018

With recent increases in distribution and numbers of feral pigs (Sus scrofa; invasive wild pigs) in North America, there has been a concurrent increase in the ecological and economic effects they have had on native and anthropogenic ecosystems. Despite the amplified interest in invasive wild pig research, there remains a significant knowledge gap regarding their basic biology and ecology, the scope of the damage they cause, and the efficacy of many control strategies. Such information is important to support the successful management of invasive wild pigs throughout North America and other areas. In 2016, members of the National Wild Pig Task Force met and developed a set of research priorities to aid in effective management of invasive wild pigs. These research priorities identify 4 topical areas where increased effort and science is most needed to manage invasive wild pigs: biology and ecology, economic and ecological damages, control strategies, and education and human dimensions, with particular emphasis on areas where specific data gaps remain within each topical area. Resolution of such knowledge deficits would advance the understanding of invasive wild pig ecology, enabling more efficient and effective management of this species. © 2018 The Wildlife Society.
Soil sealing and unsealing: State of the art and examples
Authors: Tobias Silvia , Conen Franz , Duss Adrian , Wenzel Leonore M. , Buser Christine , Alewell Christine
Published: February 2018

Soil sealing for urban and infrastructure development constitutes the most intense form of land degradation and affects all ecosystem services. Researchers and policy makers have become aware of this fact and call for limiting development and compensating for new soil sealing with unsealing measures. In a literature review, we found that the state of research about the impacts of soil sealing is far more advanced than about the potential and prerequisites of unsealing. In practice, soil restoration after mining and construction activities as well as redevelopment or renaturation of abandoned industrial sites are increasingly important issues, but systematic research on the success of soil unsealing and restoration is rare. In particular, the development of soils and vegetation after unsealing and restoration measures as well as their potential to provide ecosystem services need more detailed investigation.

In 3 case studies, we demonstrate that replacing a sealed surface with soil to restore ecosystem services is always beneficial for humans and nature. An indicator‐based mapping approach revealed the potential performance of different ecosystem services at former industrial sites in Switzerland. When unsealed sites are transformed to pioneer habitats, the intended vegetation may successfully be regained, but landscape connectivity is hardly enhanced due to increased overall landscape fragmentation. Our investigations show that with the techniques currently applied, the soil physical parameters in a restored agricultural soil developed favourably for crop growth within 15 years. However, unsealed soils are anthropogenic soils with reduced multifunctionality, and protecting natural soil against sealing is always the better option.
Damping characteristics of magneto‐rheological fluid absorber based on closed‐loop proportion integration differentiation control
Authors: Liu X. , Zhang J. , Guo T. , Yang G.
Published: February 2018

Aiming at investigating the working of magneto‐rheological fluid absorber, a test system used for detecting the damping characteristics of the magneto‐rheological fluid absorber was designed. The test system included sensors, data acquisition card, and so on. The vibration signals were detected by the sensors, put into LabVIEW data acquisition system, and then collected through the processing of closed‐loop Proportion Integration Differentiation control algorithm. Considering that the feedback current could be output to the magneto‐rheological fluid absorber by the data acquisition card, thus the damping force could be changed. The test results showed that the amplitude of the structure vibration response was obviously reduced through the closed‐loop Proportion Integration Differentiation control algorithm, and the control damping characteristics of the magneto‐rheological fluid absorber was improved.
Isothiocyanates: Translating the Power of Plants to People
Authors: Palliyaguru Dushani L. , Yuan Jian‐Min , Kensler Thomas W. , Fahey Jed W.
Published: February 2018

Isothiocyanates from cruciferous vegetables have been studied extensively in cells and in animals for their disease preventive and therapeutic effects. However, translating their utility to human populations has been both limited and challenging. Herein, clinical trials employing two isothiocyanates, sulforaphane (SFN; 1‐isothiocyanato‐4‐(methylsulfinyl) butane) and phenethyl isothiocyanate (PEITC; 2‐isothiocyanatoethylbenzene) that are isolated principally from broccoli and watercress, respectively, are summarized and discussed. Both of these compounds have been used in small human clinical trials, either within food matrices or as single agents, against a variety of diseases ranging from cancer to autism. Results suggest an opportunity to incorporate them, or more likely preparations derived from their source plants, into larger human disease mitigation efforts. The context for the applications of these compounds and plants in evidence‐based food and nutritional policy is also evaluated.
Adaptive sparse grid based HOPGD: Toward a nonintrusive strategy for constructing space‐time welding computational vademecum
Authors: Lu Y. , Blal N. , Gravouil A.
Published: February 2018

Simulation‐based engineering usually needs the construction of computational vademecum to take into account the multiparametric aspect. One example concerns the optimization and inverse identification problems encountered in welding processes. This paper presents a nonintrusive a posteriori strategy for constructing quasi‐optimal space‐time computational vademecum using the higher‐order proper generalized decomposition method. Contrary to conventional tensor decomposition methods, based on full grids (eg, parallel factor analysis/higher‐order singular value decomposition), the proposed method is adapted to sparse grids, which allows an efficient adaptive sampling in the multidimensional parameter space. In addition, a residual‐based accelerator is proposed to accelerate the higher‐order proper generalized decomposition procedure for the optimal aspect of computational vademecum. Based on a simplified welding model, different examples of computational vademecum of dimension up to 6, taking into account both geometry and material parameters, are presented. These vademecums lead to real‐time parametric solutions and can serve as handbook for engineers to deal with optimization, identification, or other problems related to repetitive task.
Optimal control of a wind energy conversion system and a wind turbine
Authors: Fathabadi Hassan
Published: February 2018

Currently, a maximum power point tracking (MPPT) unit implemented in a wind energy conversion system (WECS) extracts the maximum mechanical power from the wind turbine used in the WECS. Therefore, the MPPT unit acts as a maximum mechanical power tracker (MMPT) that performs optimal control of the wind turbine to extract the maximum mechanical power from the wind turbine. In this paper, the basic concept of a maximum electrical power tracker (MEPT) is presented both theoretically and technically. It is demonstrated that an MEPT implemented in a WECS maximizes the output electrical power of the WECS. Thus, in contrast with an MMPT, the proposed MEPT optimally controls the whole of the WECS, rather than the wind turbine, to extract the maximum electrical power from the WECS. Since, in the WECS, the power efficiency of the whole of the WECS, not the wind turbine, should be maximized to extract the maximum output electrical power from the WECS, the conventional MPPT unit acting as an MMPT should be replaced with the proposed MEPT, and this is the superiority of the proposed MEPT to an MMPT or a conventional MPPT unit. To provide experimental verifications, 2 novel MEPT and MMPT with simple structures and better performance compared to the MPPT techniques commonly used in WECSs have been constructed, which are presented in detail.
A Simple and Direct Synthesis of Pentasubstituted Pyrroles via [3+4] Annulation and Their In Vitro Evaluation as Thrombolytic Agents and Cytotoxicity Studies on L929 Cells
Authors: Balachandra Biguvu , Shanmugam Sivakumar
Published: February 2018

We have developed two different methods for synthesis of two distinct polysubstituted pyrroles. The first method proceeds by the reaction of N,S‐acetal, arylglyoxals and malononitrile in the presence of H2O / PEG400 to the synthesis of 2‐(2‐argio‐1‐methyl‐5‐(methylthio)‐4‐nitro‐1H‐pyrrol‐3‐yl)‐2‐cyanoacetamide (4a‐4p). The second method for the synthesis of other divergent pyrroles 2‐(2‐argio‐1‐methyl‐5‐(methylthio)‐4‐nitro‐1H‐pyrrol‐3‐yl)acetonitrile (6a‐6f) under solvent free at thermal condition using methylcyanoacetate instead of malononitrile by decarboxylative elimination. Among the pyrroles 2‐(4‐methoxyphenyl) (4c), 2‐(4‐fluorophenyl) (4d) 2‐(4‐chlorophenyl) (4e), 2‐(2,4‐dichlorophenyl) (4f), 2‐(3‐chloro‐4‐fluorophenyl) (4g), 2‐(2‐bromo‐4‐chlorophenyl) (4h), (2‐(3‐bromophenyl) (4i), 2‐(4‐bromophenyl) (4j), (2‐(4‐hydroxyphenyl) (4l), and 2‐(3‐nitrophenyl) (4m) displayed moderate to good clot lysis. The cytotoxicity studies were also carried out on L929 cells for selected compounds. The test derivatives4 c,4 d,4 gand4 hshowed good cell viability at lower concentration. The compound4 fshowed mild to non‐toxicity at higher and lower concentration. The density functional theory calculations (DFT) were carried out for the possible configurations of 6a‐argio‐2‐imino‐6‐methyl‐5‐(methylthio)‐4‐nitro‐3,3a,6,6a‐tetrahydro‐2H‐furo[2,3‐b] pyrrole‐3‐carbonitrile (D), 2‐amino‐6a‐argio‐6‐methyl‐5‐(methylthio)‐4‐nitro‐3a,6a‐dihydro‐6H‐furo[2,3‐b]pyrrole‐3‐carbonitrile (E) and4c.
Formation Mechanism of Polymeric Thin Films of Azure B on Gold Electrodes
Authors: Bayındır Oğuz , Alanyalıoğlu Murat
Published: February 2018

Phenothiazine derivative dyes are preferred as the main material for the formation of nanocomposites because of their electrocatalytic activity, good interaction with many materials, and easy electropolymerized film formation. Therefore, the formation mechanism of polymer thin films needs to be investigated by using both theoretical models and advanced spectroscopic techniques. Electropolymerization of azure B (AB) is supplied by both cyclic voltammetry and chronoamperometry. Some parameters have been questioned for the formation of poly(AB) thin films. Nucleation and growth mechanism of electropolymerization of AB was investigated by chronoamperometry, in which current density‐time transients were fitted to related theoretical models. Morphological characteristics of poly(AB) thin films were examined by scanning tunneling microscopy and scanning electron microscopy. The chemical composition of the polymerized thin film was acquired by electron dispersive X‐ray analysis. Optical characterization of both dissolved and solid‐state samples was achieved by UV‐Vis. absorption spectroscopy. It has been determined that early stages of electropolymerization of AB reveal random adsorption of poly(AB) species but regular polymeric thin film forms with the first progressive and then instantaneous mechanisms by the time.
InCl3‐Assisted Eco‐Friendly Approach for N‐Fused 1,4‐Dihydropyridine Scaffolds via Ring Opening Michael Addition of Cyclic Nitroketene and Iminocoumarin: Synthesis and DFT Studies
Authors: Elumalai Dhanasekar , Gnanasekaran Ramachandran , Leelakrishnan Saraswathi , Nachimuthu Gunavathy , Kannan Tharanikkarasu , Paramasivam Thirumalai Perumal , Jayabal Kamalraja
Published: February 2018

A novel strategy was developed for the synthesis of five different N‐fused 1,4‐dihydropyridine (1,4 DHP) scaffolds such as imidazopyridine, pyridopyrimidine, benzoimidazopyridine, thiazolopyridine and benzopyridooxazine derivatives by coupling nitroketene S,S‐acetal, various nitrogen containing dinucleophiles, malanonitrile and substituted salicylaldehydes/aldehydes in the presence of InCl3 as catalyst in water‐EtOH solvent mixture under reflux condition. Furthermore, mechanism for the formation of 1,4‐DHPs was explored through experimental and DFT calculations. DFT studies reveal that the reaction went through lower energy triheterocyclic intermediate than the higher energy chromenoimidazopyridine imtermediate. The attractive features of this protocol include short reaction time, easy separation of the product without chromatographic purification, simple execution with excellent yield and possibility to synthesize structurally diverse 1,4‐dihydropyridine derivatives through greener approach.
Palladium‐Catalyzed Direct α‐Arylation of Methane Sulfonamides with Aryl Bromides
Authors: Gao Gui , Chen Xiang‐Zhu , Wang Zhong‐Yu , Zhang Yuan‐Yuan , Liu Jing‐Jing , Hou Shi‐Cong
Published: February 2018

An effective palladium‐catalyzed cross‐coupling approach for the direct α‐monoarylation of various methane sulfonamides using aryl bromides to access benzylic sulfonamides is presented. Electron‐deficient, electron‐rich, and heterocyclic aryl bromides were successfully cross‐coupled, and sensitive functional groups were well tolerated. High reactivities and chemoselectivities were achieved using a combination of Pd(OAc)2 and Kwong's indole‐based phosphine ligand. The application of the developed method to the synthesis of the biologically active 1‐benzyl‐4‐(benzylsulfonyl)piperazine is also demonstrated.
Trace Amount of Platinum Supported on Carbonized Biomorphic Wood for Efficient Electrochemical Hydrogen Evolution in Alkaline Condition
Authors: Wang Meng , Gönüllü Yakup , Pyeon Myeongwhun , Diao Zhidan , Czympiel Lisa , Singh Mrityunjay , Shen Shaohua , Mathur Sanjay
Published: February 2018

Carbonized biomorphic wood (Bio‐C), which features unique properties such as highly ordered microtexture, well‐developed porous structure, and low charge transfer resistance, was prepared as a promising scaffold with trace amount of platinum (Pt) supported to efficiently electrocatalyze hydrogen evolution reaction (HER). Pt/Bio‐C nanocomposites demonstrated superior HER activity with a current density reaching as high as ∼58 mA cm−2 at −0.2 V vs. reversible hydrogen electrode (RHE) in strongly alkaline condition.
NOT‐INHIBIT Reversible Logic Gate Behavior of g‐C3N4‐Hg2+‐Complexed Nanoparticles
Authors: Shiravand Ghasem , Badiei Alireza , Jafari Maryam , Shayesteh Alireza , Ziarani Ghodsi Mohammadi
Published: February 2018

The g‐C3N4‐Hg2+ complexed nanoparticles with two fluorescence emission (at 368 and 450 nm) have been synthesized and characterized with scanning electron microscope, transmittance electron microscope, Fourier‐transform infrared spectroscopy, ultraviolet‐ visible spectrophotometer and X‐ray diffraction methods. A decrease in the XRD peak intensity of g‐C3N4‐Hg2+ at 13.4° suggested that Hg2+ ions might be trapped into the in‐plane heptazine holes. Computational studies of g‐C3N4‐Hg2+ nanoparticles confirmed large binding energies for in‐plan‐Hg2+ structures and suggested that the fluorescence quenching (at 368 nm) is caused by the complexation of nanoparticles with Hg2+ ions. Due to the strong affinity between Hg2+ and CN− confirmed by computational studies, the quenched fluorescence emission at 368 nm “OFF” can be completely returned “ON” in the presence of CN− and then efficiently quenched by the addition of Hg2+. The OFF‐ON‐OFF fluorescence cycles have been exploited to design an “INHIBIT” logic gate using Hg2+ and CN− ions. In addition, the second emission peak (at 450 nm) was quenched by Cr2O72− and was not affected by other ions (Hg2+ and CN−) indicating a “NOT” (inverter) logic gate.
Efficient Synthesis of Propargylamines in Aqueous Media Catalyzed by Au Nanoparticles under Ambient Temperature
Authors: Moghaddam Firouz Matloubi , Pourkaveh Raheleh
Published: February 2018

An eco‐friendly gold‐based catalyst supported on proline decorated montmorillonite was synthesized. The catalyst was characterized by combination of Fourier‐transform infrared spectroscopy (FT‐IR), Field Emission Scanning Electron Microscopy (FE‐SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Brunauer–Emmett Teller (BET) surface area analysis, Ultraviolet–visible spectroscopy (UV‐Vis), Energy‐dispersive X‐ray spectroscopy (EDX), thermo gravimetric analysis (TGA) and atomic absorption spectroscopy (AAS) techniques. The synthesized catalyst was found to be a highly efficient heterogeneous nanocatalyst for multi component A3 coupling reaction of aldehyde, amine and alkyne in water as a green solvent at room temperature. This novel catalyst promotes multicomponent reaction of a large library of functional substrates under mild and sustainable conditions (water as a green solvent at ambient temperature). In addition, the catalyst could be easily recovered by simple filtration and reused for at least 6 cycles without losing its activity.
Surface Oxidation of AuNi Heterodimers to Achieve High Activities toward Hydrogen/Oxygen Evolution and Oxygen Reduction Reactions
Authors: Ni Bing , He Peng , Liao Wenxin , Chen Shuangming , Gu Lin , Gong Yue , Wang Kai , Zhuang Jing , Song Li , Zhou Gang , Wang Xun
Published: February 2018

Although much attention has been paid to the exploration of highly active electrocatalysts, especially catalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), the development of multifunctional catalysts remains a challenge. Here, we utilize AuNi heterodimers as the starting materials to achieve high activities toward HER, OER and ORR. The HER and ORR activities in an alkali environment are similar to those of Pt catalysts, and the OER activity is very high and better than that of commercial IrO2. Both the experimental and calculated results suggest that the surface oxidation under oxidative conditions is the main reason for the different activities. The NiO/Ni interface which exists in the as‐synthesized heterodimers contributes to high HER activity, the Ni(OH)2‐Ni‐Au interface and the surface Ni(OH)2 obtained in electrochemical conditons gives rise to promising ORR and OER activities, respectively. As a comparison, a Au@Ni core‐shell structure is also synthesized and examined. The core‐shell structure shows lower activities for HER and OER than the heterodimers, and reduces O2 selectively to H2O2. The work here allows for the development of a method to design multifunctional catalysts via the partial oxidation of a metal surface to create different active centers.
Development of steel angles as energy dissipation devices for rocking connections
Authors: Marreiros Rui , Lúcio Válter , Pampanin Stefano
Published: February 2018

This paper focuses on the development of energy dissipaters for rocking precast systems. The energy dissipaters developed in this work are to be used externally, having the advantages of being easy to inspect and replace after an earthquake. The main parameters to take into account for the development of the energy dissipaters are the cyclic behavior, the strength, and the ductility. The cyclic behavior has to be stable from cycle to cycle. The developed dissipater has to respond with adequate strength. The ductility is also important as the dissipater has to sustain the displacements applied by a major seismic event without failure. For this purpose, the experimental campaign using steel structural angles as dissipaters is described and solutions able to deliver the desired behavior are shown. To support and complement the experimental tests, two‐dimensional numerical models using a finite element software are shown and an analytical method is also presented to describe the behavior in both elastic and plastic ranges and thus design the elements. In both cases, good agreement with the experimental results is achieved. The analytical method has the advantage of being easy to implement for estimation of the steel angle response.
Model‐based reasoning about energy: A fourth‐grade case study
Authors: Tobin Roger G. , Lacy Sara J. , Crissman Sally , Haddad Nick
Published: February 2018

We report a case study of model‐based reasoning in which a small group of fourth‐grade students analyzes the energy flow when a solar panel is used to power an electric motor that spins a propeller. In developing their explanation of energy flow, the students draw on a general model of energy developed collectively by their class in the course of an experimental classroom curriculum led by a trained teacher. They also construct a model‐based representation of the specific system under study. Their investigation and reasoning process exhibit all the features of authentic scientific model‐based inquiry, including the revision of their models to incorporate new information. In the course of their work the students recruit and seamlessly integrate nearly all of the practices of science designated in the Next Generation Science Standards. This case study provides an example of what modeling‐based teaching and learning can look like in an elementary school classroom. It also suggests that the study of energy offers a particularly promising context for developing students' use of science practices, especially the practice of developing and using models.