bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracturing on the Factory floor by ettringite
Authors: Nguyen Thong Huynh , Bui Vinh Trong , Dang Diep Huu
Published: September 2018

In foundation of Dong Nai factory contains mineral Pyrite. The process of pyrite oxide will create products sulfuric acid. Physicochemical effects between sulfuric acid and calcium hydroxide in the composition of cement concrete increase calcium sulfoaluminate called Ettringite. This process makes concrete material volume expansion, swelling, causing swelling capacity, making tensile strength of concrete fell from the cracked concrete that make up the cracks separating, forming networks slots cracked surface not rule on the factory floor. Simultaneously with the chemical effects between cement concrete causes swelling, physical effects of sulfate salt crystals forming on the surface of the holes and cracks formed increasing the capacity of the concrete expansion, increased tensile stress in concrete, making the surface more and more intense fracturing.
Removal of nonyl phenol ethoxylates in water by catalytic ozonation in presence of silica supported - cobalt nanoparticles
Authors: Tran Tri Truong Trong , Nguyen My Thi Mai , Nguyen Hanh Ngoc , Vo Thao Huu
Published: September 2018

The catalytic ozonation of nonionic surfactant nonylphenolethoxylate (NPE) as pollutant in wastewater and its degradation in the presence of silica-supported Cobalt oxide nanoparticles was studied. Characterization of silica supported- cobalt oxide was made using XRD patterns and SEM profiles. The influence of pH, initial NPE concentration, ozonation time and catalyst contents in ozonation process was also investigated. Results show that NPE removals by using silica supported-cobalt oxide catalytic systems are higher than that of using single ozonation. About 99% NPE were removed within 10 min at 30oC. Furthermore, in this condition more than 50% of total carbon of NPE was mineralized.
Biochars Improve Nutrient Phyto-Availability of Hawai’i’s Highly Weathered Soils
Authors: Berek Arnoldus Klau , Hue Nguyen V. , Radovich Theodore J. K. , Ahmad Amjad A.
Published: September 2018

Highly weathered soils in Hawai’i are low in fertility, negatively affecting plant growth. The potential of biochar for improving soil nutrient availability to crops is promising, and prompts this study. Two biochars at 2% (w/w) made of lac tree (Schleichera oleosa (Lour.) Oken) wood and mixed wood (scrapped wood and tree trimmings) with and without vermicompost or thermocompost at 2% (w/w) were added to an Ultisol (Ustic Kanhaplohumult, Leilehua series) and an Oxisol (Rhodic haplustox, Wahiawa series) of Hawai’i. In each soil two additional treatments—lime + compost and un-amended soil—served as the control. Chinese cabbage (Brassica rapa cv. Bonsai) was used as the test plant in two greenhouse plantings, which had a factorial completely randomized design with three replicates per treatment. The results indicated that soil acidity, nutrient in the soils, plant growth and nutrient uptake were improved by the amendments compared to the control. The combined additions of biochar and compost significantly increased pH and EC; reduced exchangeable Al; reduced Mn and Fe in the Oxisol; increased P, K, and Ca content of the soils; and increased Ca, Mg and Fe uptake. Exchangeable aluminum in the Ultisol decreased from 2.5 cmol+/kg to nil; Mehlich-3 extractable P, K, Ca, Mg, Fe, and Mn in the Ultisol increased by 1478%, 2257%, 1457%, 258%, 125% and 72%, respectively compared to the un-amended soil, while the same nutrients increased or decreased in the Oxisol by 180%, 59%, 308%, −14%, and −36%, respectively. Shoot and total cabbage fresh and dry matters increased by 94%, 96%, 107%, and 112%, respectively, as compared to the lime plus compost treatment. Cabbage growth in the Ultisol amended with the lac tree wood biochar and vermicompost was almost twice over the lime and vermicompost treatment. Essential nutrients in the plant tissues, except for N and K, were sufficient for the cabbage growth, suggesting increases in nutrients and reduced soil acidity by the additions of biochar combined with compost were the probable cause. It is recommended that locally produced biochars and composts be used to improve plant nutrient availability in the highly weathered soils.
Sub-Wavelength Scale Si Inverted Pyramid Fabrication with Enhanced Size Control by Using Silica Sphere Lithography Technique
Authors: Choi Jea-Young , Honsberg Christiana B.
Published: September 2018

In this paper, we present a novel silicon (Si) subwavelength-scale surface structure (SWSS) fabrication process using the silica sphere (SS) lithography technique, which allows controllable geometries. The process involves a new cost-effective solvent-controlled spin-coating method that deposits SS on large Si surface areas with enhanced SS monolayer coverage and uniformity compared to conventional methods. The larger areas and rapid, low cost processing allow colloidal sphere lithography to be realistically used for solar cells. We successfully demonstrate 1.57 μm diameter SS on a 2-inch round Si wafer with more than 95% SS monolayer coverage and great uniformity. Using these deposited SS, a SWSS fabrication process was designed and successfully demonstrated Si inverted pyramid structures with dimension on the order of 1.1 μm, thus potentially providing a new technique for effective light-management of thin crystalline Si solar cells.
Occupational Stress and Workplace Design
Authors: Hui Felix Kin Peng , Aye Lu
Published: September 2018

The World Green Building Council (WGBC) advocates improvements in employee health, wellbeing, and productivity in buildings as people are about 90% of an organisation’s expense and well exceed building costs and energy costs. It was reported that earlier research on workplace design primarily focused on physical arrangement of employees’ immediate work area, and ambient environmental qualities of the work area. Building organisation, exterior amenities, and site-planning have been given less attention. Therefore, we examine more closely the health relevance of both proximal and remote aspects of workplace design. Occupational stress is a complex phenomenon that is dynamic and evolving over time. This investigation reviews the existing fundamental conceptual models of occupational stress, workplace design, and connection to nature. It aims to develop an improved model relevant to work place design and occupational stress linked with connection to nature. The proposed improved model is presented with an appropriate causal loop diagram to assist in visualizing how different variables in a system are interrelated. The developed model highlights how connection to nature in workspaces can function as a work resource with a dual effect of improving physical wellbeing and psychological wellbeing.
Connecting Smart Objects in IoT Architectures by Screen Remote Monitoring and Control
Authors: Yang Zebo , Nakajima Tatsuo
Published: September 2018

Electronic visual display enabled by touchscreen technologies evolves as one of the universal multimedia output methods and a popular input intermediate with touch–interaction. As a result, we can always gain access of an intelligent machine by obtaining control of its display contents. Since remote screen sharing systems are also increasingly prevalent, we propose a cross-platform middleware infrastructure which supports remote monitoring and control functionalities based on remote streaming for networked intelligent devices such as smart phone, computer and smart watch, etc. and home appliances such as smart refrigerator, smart air-conditioner and smart TV, etc. We aim to connect all these devices with display screens, so as to make possible remote monitoring and controlling a certain device by whichever one (usually the nearest one) of display screens among the network. The system is a distributed network consisting of multiple modular nodes of server and client, and is compatible to prevalent operating systems such as Windows, macOS, Unix-like/Linux and Android, etc.
“There Is Never a Break”: The Hidden Curriculum of Professionalization for Engineering Faculty
Authors: Villanueva Idalis , Carothers Taya , Di Stefano Marialuisa , Khan Md. Tarique Hasan
Published: September 2018

The purpose of this exploratory special issue study was to understand the hidden curriculum (HC), or the unwritten, unofficial, or unintended lessons, around the professionalization of engineering faculty across institutions of higher education. Additionally, how engineering faculty connected the role of HC awareness, emotions, self-efficacy, and self-advocacy concepts was studied. A mixed-method survey was disseminated to 55 engineering faculties across 54 institutions of higher education in the United States. Quantitative questions, which centered around the influences that gender, race, faculty rank, and institutional type played in participants’ responses was analyzed using a combination of decision tree analysis with chi-square and correlational analysis. Qualitative questions were analyzed by a combination of tone-, open-, and focused-coding. The findings pointed to the primary roles that gender and institutional type (e.g., Tier 1) played in issues of fulfilling the professional expectations of the field. Furthermore, it was found that HC awareness and emotions and HC awareness and self-efficacy had moderate positive correlations, whereas, compared to self-advocacy, it had weak, negative correlations. Together, the findings point to the complex understandings and intersectional lived realities of many engineering faculty and hopes that through its findings can create awareness of the challenges and obstacles present in these professional environments.
Critical Theoretical Frameworks in Engineering Education: An Anti-Deficit and Liberative Approach
Authors: Mejia Joel Alejandro , Revelo Renata A. , Villanueva Idalis , Mejia Janice
Published: September 2018

The field of engineering education has adapted different theoretical frameworks from a wide range of disciplines to explore issues of education, diversity, and inclusion among others. The number of theoretical frameworks that explore these issues using a critical perspective has been increasing in the past few years. In this review of the literature, we present an analysis that draws from Freire’s principles of critical andragogy and pedagogy. Using a set of inclusion criteria, we selected 33 research articles that used critical theoretical frameworks as part of our systematic review of the literature. We argue that critical theoretical frameworks are necessary to develop anti-deficit approaches to engineering education research. We show how engineering education research could frame questions and guide research designs using critical theoretical frameworks for the purpose of liberation.
A Simplified Design Inline Microstrip-to-Waveguide Transition
Authors: Pérez-Escudero José , Torres-García Alicia , Gonzalo Ramón , Ederra Iñigo
Published: September 2018

A simplified design of an inline transition between microstrip and rectangular waveguide is presented in this paper. The transition makes use of a dielectric filled rectangular waveguide (DFRW) as an intermediate step, which simplifies manufacturing and allows for an analytical design. The behavior of the transition has been experimentally validated in the W-band by means of a back-to-back configuration. Good performance has been achieved: a return loss greaterthan 10 dB and mean insertion loss lower than 1 dB.
Mechanical Behavior of High-Performance Yarns Transversely Loaded by Different Indenters
Authors: Lim Boon , Chu Jou-Mei , Chen Wayne
Published: September 2018

In this study, we performed off-axis transverse loading experiments to study the stress concentration developed in a high-performance yarn with different indenters. A universal testing machine was utilized to perform quasi-static transverse loading experiments on Twaron® yarns. Seven different round indenters possessing radius of curvature ranging from 0.20 to 4.50 mm were employed in the experiments. In addition, post-mortem failure analysis was performed on the recovered specimens via a scanning electron microscope. From the transverse loading experiments, the results showed that, as the radius of curvature of the indenters increased, the concentrated load decreased, causing the failure surfaces to change from a combination of kink band, snapped-back, and localized shear to only fibrillations. The concentrated stresses were predicted by a strain energy model when loaded by an indenter with a radius of curvature smaller than 1.59 mm. For indenters larger than 1.59 mm, the specimens failed in fibrillation, the concentrated stresses agreed well with the stresses predicted by quasi-static circular curved beam theory.
Generalized Memory: Fractional Calculus Approach
Authors: Tarasov Vasily E.
Published: September 2018

The memory means an existence of output (response, endogenous variable) at the present time that depends on the history of the change of the input (impact, exogenous variable) on a finite (or infinite) time interval. The memory can be described by the function that is called the memory function, which is a kernel of the integro-differential operator. The main purpose of the paper is to answer the question of the possibility of using the fractional calculus, when the memory function does not have a power-law form. Using the generalized Taylor series in the Trujillo-Rivero-Bonilla (TRB) form for the memory function, we represent the integro-differential equations with memory functions by fractional integral and differential equations with derivatives and integrals of non-integer orders. This allows us to describe general economic dynamics with memory by the methods of fractional calculus. We prove that equation of the generalized accelerator with the TRB memory function can be represented by as a composition of actions of the accelerator with simplest power-law memory and the multi-parametric power-law multiplier. As an example of application of the suggested approach, we consider a generalization of the Harrod-Domar growth model with continuous time.
Development and Psychometric Properties of The Delayed Childbearing Questionnaire (DCBQ-55)
Authors: Behboudi-Gandevani Samira , Ziaei Saeideh , Kazemnejad Anoshirvan , Khalajabadi Farahani Farideh , Vaismoradi Mojtaba
Published: September 2018

The comprehensive assessment of delayed childbearing needs a valid and reliable instrument. Therefore, the aim of the present study was to develop an instrument to evaluate factors influencing delayed childbearing among women and to assess its psychometric properties. The current methodological study was performed in two phases of (i) qualitative instrument development, and (ii) quantitative psychometric assessment of the developed instrument. Face and content validity of the instrument was assessed by eligible women and a panel of experts. Construct validity was assessed using the exploratory factor analysis (EFA). For reliability, internal consistency reliability and intra-rater reliability analysis were used. The initial instrument developed from the qualitative phase consisted of 60 items, which were reduced to 55 items after the face and content validity processes. EFA (n = 300) using the Kaiser criteria (Eigenvalues > 1) and the scree plot led to a six-factor solution accounting for 61.24% of the observed variance. The Cronbach’s alpha coefficient, Spearman’s correlation, test–retest and intra-class correlation coefficients for the whole instrument were reported as 0.83, 0.86 and 0.81, respectively. The final instrument entitled the delayed childbearing questionnaire (DCBQ-55) included 50 items with six domains of ‘readiness for childbearing’, ‘stability in the partner relationship’, ‘awareness about the adverse outcomes of pregnancy in advanced maternal age’, ‘attitude toward delayed childbearing’, ‘family support’, and ‘social support’ on a five-point Likert scale. The DCBQ-55 as a simple, valid and reliable instrument can assess factors influencing delayed childbearing. It can be used by reproductive healthcare providers and policy makers to understand factors influencing delayed childbearing and devise appropriate strategies.
Incremental Road Network Generation Based on Vehicle Trajectories
Authors: Ni Zhongyi , Xie Lijun , Xie Tian , Shi Binhua , Zheng Yao
Published: September 2018

Nowadays, most vehicles are equipped with positioning devices such as GPS which can generate a tremendous amount of trajectory data and upload them to the server in real time. The trajectory data can reveal the shape and evolution of the road network and therefore has an important value for road planning, vehicle navigation, traffic analysis, and so on. In this paper, a road network generation method is proposed based on the incremental learning of vehicle trajectories. Firstly, the input vehicle trajectory data are cleaned by a preprocess module. Then, the original scattered positions are clustered and mapped to the representation points which stand for the feature points of the real roads. After that, the corresponding representation points are connected based on the original connection information of the trajectories. Finally, all representation points are connected by a Delaunay triangulation network and the real road segments are found by a shortest path searching approach between the connected representation point pairs. Experiments show that this method can build the road network from scratch and refine it with the input data continuously. Both the accuracy and timeliness of the extracted road network can continuously be improved with the growth of real-time trajectory data.
Galectin-3 Interacts with Vascular Cell Adhesion Molecule-1 to Increase Cardiovascular Mortality in Hemodialysis Patients
Authors: Ko Wen-Chin , Choy Cheuk-Sing , Lin Wei-Ning , Chang Shu-Wei , Liou Jian-Chiun , Tung Tao-Hsin , Hsieh Chih-Yu , Chang Jia-Feng
Published: September 2018

Background: Interactions and joint effects of galectin-3 and vascular cell adhesion molecule 1 (VCAM-1) on risks of all-cause and cardiovascular (CV) mortality remain unclear in patients with maintenance hemodialysis (MHD). Methods: Unadjusted and adjusted hazard ratios (aHRs) of mortality risks were analyzed between higher and lower concentration groups of serum galectin-3 and VCAM-1. The modification effect between serum galectin-3 and VCAM-1 on mortality risk was investigated using an interaction product term. Results: During follow-up, galectin-3 and VCAM-1 were associated with incremental risks of all-cause mortality (aHR: 1.038 (95% confidence interval (CI): 1.001–1.077) and 1.002 (95% CI: 1.001–1.003), respectively). Nonetheless, VCAM-1 but not galectin-3 predicted CV mortality (aHR: 1.043 (95% CI: 0.993–1.096) and 1.002 (95% CI: 1.001–1.003), respectively). In the interaction analysis, patients with combined higher galectin-3 (>29.5 ng/mL) and VCAM-1 (>1546.9 ng/mL) were at the greatest risk of all-cause and CV mortality (aHR: 4.6 (95% CI: 1.6–13.4), and 4.2 (95% CI: 1.3–14.4), respectively). The interactions between galectin-3 and VCAM-1 with respect to all-cause and CV mortality were statistically significant (p < 0.01 and < 0.05, respectively). Conclusion: Galectin-3 and VCAM-1 could serve as a promising dual biomarker for prognostic assessment, considering their joint effects on pathogenesis of leukocyte trafficking and atherothrombosis.
Effect of Acute Exercise Mode on Serum Brain-Derived Neurotrophic Factor (BDNF) and Task Switching Performance
Authors: Hung Chiao-Ling , Tseng Jun-Wei , Chao Hsiao-Han , Hung Tsung-Min , Wang Ho-Seng
Published: September 2018

Previous studies have consistently reported a positive effect of acute exercise on cognition, particularly on executive function. However, most studies have focused on aerobic and resistant forms of exercise. The purpose of this study was to compare the effect of ‘open-skill’ with ‘closed-skill’ exercise (defined in terms of the predictability of the performing environment) on brain-derived neurotrophic factor (BDNF) production and task switching performance. Twenty young adult males participated in both closed (running) and open (badminton) skill exercise sessions in a counterbalanced order on separate days. The exercise sessions consisted of 5 min of warm up exercises followed by 30 min of running or badminton. The exercise intensity was set at 60% (±5%) of the heart rate reserve level (HRR) with HR being monitored by a wireless heart rate monitor. Blood samples were taken and participation in a task-switching paradigm occurred before and after each exercise session. Results showed no differences in serum BDNF or task-switching performance at the pre-test stage, however, badminton exercise resulted in significantly higher serum BDNF levels (a proxy for levels of BDNF in the brain) and near significant smaller global switching costs relative to running. This study has provided preliminary evidence in support the relative benefits of open-skills exercises on BDNF and executive function.
Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures
Authors: Chen Zhiyuan , Dang Jie , Hu Xiaojun , Yan Hongyan
Published: September 2018

Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles.
Granulocyte-Colony-Stimulating Factor Alters the Proteomic Landscape of the Ventral Tegmental Area
Authors: Mervosh Nicholas L. , Wilson Rashaun , Rauniyar Navin , Hofford Rebecca S. , Kutlu Munir Gunes , Calipari Erin S. , Lam TuKiet T. , Kiraly Drew D.
Published: September 2018

Cocaine addiction is characterized by aberrant plasticity of the mesolimbic dopamine circuit, leading to dysregulation of motivation to seek and take drug. Despite the significant toll that cocaine use disorder exacts on society, there are currently no available pharmacotherapies. We have recently identified granulocyte-colony stimulating factor (G-CSF) as a soluble cytokine that alters the behavioral response to cocaine and which increases dopamine release from the ventral tegmental area (VTA). Despite these known effects on behavior and neurophysiology, the molecular mechanisms by which G-CSF affects brain function are unclear. In this study mice were treated with repeated injections of G-CSF, cocaine or a combination and changes in protein expression in the VTA were examined using an unbiased proteomics approach. Repeated G-CSF treatment resulted in alterations in multiple signaling pathways related to synaptic plasticity and neuronal morphology. While the treatment groups had marked overlap in their effect, injections of cocaine and the combination of cocaine and G-CSF lead to distinct patterns of significantly regulated proteins. These experiments provide valuable information as to the molecular pathways that G-CSF activates in an important limbic brain region and will help to guide further characterization of G-CSF function and evaluation as a possible translational target.
Market Segmentation by Travel Motivations under a Transforming Economy: Evidence from the Monte Carlo of the Orient
Authors: Shi Tiantian (Tiana) , Liu Xiaoming (Rose) , Li Jun (Justin)
Published: September 2018

Macau, the world’s largest casino hub with the largest gambling revenues, has received increasing attention as a research focus. Macau attracts more and more Chinese outbound tourists each year due to its gambling industry monopoly in Greater China. Macau is positioning itself as a ‘world center of tourism and leisure’ and has set out plans to become a broader-based tourist destination with economic diversification. Thus, an understanding of people’s varied motivations plays an important role in the current status of an environment with a moderate diversification of economic development. The objective of this study is to classify the outbound mainland Chinese tourists in Macau into more homogeneous subgroups on the basis of their travel motivations. Thirteen motivation items are extracted into four factors (namely knowledge and culture, relaxation, entertainment and gambling, and prestige) through exploratory factor analysis. Three distinct market segments are identified—freedom seekers, multi-purpose seekers, and fun and special interest in gambling seekers—based on a cluster analysis using k-means methodology. This study also presents the socio-demographic and trip characteristic differences among these three segments.
Immunizing the Immune: Can We Overcome Influenza’s Most Formidable Challenge?
Authors: Ellebedy Ali H.
Published: September 2018

The first human influenza virus was isolated more than 85 years ago, and several vaccine candidates were developed and tested soon after. Yet, controlling infections mediated by this respiratory pathogen continues to present a formidable challenge. Development of an effective influenza vaccine has been undermined by the dynamic nature of influenza viruses: these viruses have the unique capacity to escape pre-existing immunity. In this perspective, I highlight pre-existing immunity as a different, but related, hurdle that may actually lessen the effectiveness of influenza vaccine-induced immune responses. Specifically, I discuss the impact of pre-existing immunity on the generation of de novo B cell responses to influenza vaccination. As the influenza virus changes its major antigenic determinants, it creates new ones in the process. Our immune system adapts by targeting the new determinants. However, pre-existing antibodies and memory B cells interfere with the generation of de novo responses against these newly formed epitopes, rendering vaccines less effective. Overcoming such interference is essential for the development of more effective influenza vaccines.
Baseflow Contribution to Streamflow and Aquatic Habitats Using Physical Habitat Simulations
Authors: Choi Byungwoong , Kang Hyeongsik , Lee Woong Hee
Published: September 2018

A scientific understanding of the baseflow contribution to streams and watershed processes is critical when dealing with water policy and management issues. However, most previous studies involving physical habitat simulation have been performed without considering the seepage of water from the underground into streams. Motivated by this, herein, we report an investigation of the impact of baseflow using physical habitat simulations for both dominant fish and benthic macroinvertebrate. The study area was located along the reach of the Ungcheon Stream, located 16.50 km downstream and 11.75 km upstream from the Boryeong Dam in the Republic of Korea. For the physical habitat simulation, Zacco platypus and Baetis fuscatus were selected as the target fish and benthic macroinvertebrate, respectively. The HydroGeoSphere (HGS) model (Aquanty Inc., Waterloo, ON, Canada) and the River2D model (Version 0.95a, University of Alberta, Edmonton, AB, Canada) were used for hydrologic and hydraulic simulations, respectively. The Habitat Suitability Index (HSI) model was used for the habitat simulations. Three habitat variables, flow depth, velocity, and substrate, were used. To assess the impact of baseflow, this study performed a physical habitat simulation using each representative discharge, with and without considering baseflow. It was found that the baseflow effects significantly increase the habitat suitability in the study reach. To restore the aquatic habitat, a scenario for modifying dam operations through natural flow patterns is presented using the Building Block Approach (BBA). In the study, the adjusted minimum flow allocation concept was used. It was revealed that the modified dam operations significantly increased the Weighted Usable Area (WUA) by about 48% for both target species. The results indicate that modifying the dam operations through restoration to natural flow regimes but also through inclusion of the baseflow are advantageous to aquatic fish habitats.
Removal of Nutrients, Sediment, and Heavy Metals by a Stormwater Treatment Train; a Medium-Density Residential Case Study in Southeast Queensland
Authors: Drapper Darren , Hornbuckle Andy
Published: September 2018

Urban stormwater runoff from a medium-density residential development in southeast Queensland has been monitored in the field since November 2013. A treatment train installed on the site includes rainwater tanks collecting roofwater, 200-micron mesh baskets installed in grated gully pits, and two 850-mm-high media filtration cartridges installed in an underground 4-m3 vault. The site has been monitored over a 4.5-year period. Removal efficiencies were observed at this site for the regulated pollutants; the corresponding values for total suspended solids (TSS), total phosphorus (TP), and total nitrogen (TN) for the pit baskets were 61%, 28%, and 45%, respectively. The cartridge filters removed 78% of TSS, 59% of TP, 42% of TN, 40% of total copper, and 51% of total zinc. As the measured influent TSS and TP concentrations to the cartridge filters were low when compared to industry guidelines, the U.S. field dataset was truncated to anticipated guideline levels, confirming results at 90% for TSS and 76% for TP. The total gross pollutant generation rate from the medium-density residential catchment was observed to be 0.24 m3/Ha/year, with a corresponding air-dried mass of 142.5 kg/Ha/year. Less than 2% of the gross pollutant mass was anthropogenic. This paper concludes that the treatment train, and in particular the media filter, provides good removal of total copper and total zinc as well as TSS, TP, and TN from urban stormwater runoff, with higher inlet concentrations producing better performance. Field test data from 58 months of operation and standard maintenance suggests that breakthrough of TSS and TP has not occurred yet.
Developing an EFDC and Numerical Source-Apportionment Model for Nitrogen and Phosphorus Contribution Analysis in a Lake Basin
Authors: Bai Hui , Chen Yan , Wang Dong , Zou Rui , Zhang Huanzhen , Ye Rui , Ma Wenjing , Sun Yunhai
Published: September 2018

The numerical source-apportionment model is an efficient and useful method for analyzing water-quality responses to nutrient loading in rivers and lakes. In this study, the Environmental Fluid Dynamic Code (EFDC) and numerical source-apportionment model were applied to Lake Bali in Jiujiang City, China to predict the contributions of various pollution sources to the lake at any time and position. We calibrated and validated the model by comparing its predictions with observed hydrodynamic and water-quality parameters from 2014 to 2015. Application of the calibrated model to simulate water-quality responses to a pollution source showed that the contribution of a pollution source to water quality in the lake has strong spatial heterogeneity. The results provide useful information for the optimization of pollution load reduction in Lake Bali and can be used to determine the most effective implementation of its pollution-control plan. The model built in this study can also be used for pollution source-apportionment in other urban lakes and is superior to other traditional source-apportionment models.
Effects of discontinuation of chronic medication in primary care: a systematic review of deprescribing trials
Authors: Thio Sioe Lie , Nam Joana , van Driel Mieke L , Dirven Thomas , Blom Jeanet W
Published: September 2018

Background

Polypharmacy is becoming more prevalent and evaluation of appropriateness of medication use is increasingly important. The primary care physician often conducts the deprescribing process; however, there are several barriers to implementing this.

Aim

To examine the feasibility and safety of discontinuation of medication, with a focus on studies that have been conducted in the community, that is, primary care (or general practice) and nursing homes.

Design and setting

This systematic review included randomised controlled trials published in 2005–2017, which studied withdrawal of long-term drugs prescribed in primary care settings and compared continuing medication with discontinuing.

Method

PubMed and EMBASE searches were conducted and the extracted data included the number of patients who successfully stopped medication and the number of patients who experienced relapse of symptoms or restarted medication.

Results

A total of 27 studies reported in 26 papers were included in this review. The number of participants in the studies varied from 20 to 2471 and the mean age of participants ranged from 50.3 years to 89.2 years. The proportion of patients who successfully stopped their medication varied from 20% to 100%, and the range of reported relapse varied from 1.9% to 80%.

Conclusion

Only a few studies have examined the success rate and safety of discontinuing medication in primary care, and these studies are very heterogeneous. Most studies show that deprescribing and cessation of long-term use seem safe; however, there is a risk of relapse of symptoms. More research is needed to advise physicians in making evidence-based decisions about deprescribing in primary care settings.
GPs’ experiences and perceptions of early detection of liver disease: a qualitative study in primary care
Authors: Standing Holly C , Jarvis Helen , Orr James , Exley Catherine , Hudson Mark , Kaner Eileen , Hanratty Barbara
Published: September 2018

Background

The incidence of liver disease is increasing in the UK and primary care is a key setting where improvement in the detection and management of liver disease is required. Little is known about GPs’ understanding and confidence in detecting liver disease.

Aim

To explore GPs’ experiences of liver disease with a focus on early detection and interpretation of liver function tests (LFTs).

Design and setting

A qualitative study employing semi-structured interviews of a purposive sample of GPs from five UK primary care study sites.

Method

Telephone and face-to-face interviews of GPs were undertaken. Data were analysed thematically, using a constant comparative approach.

Results

From a total of 25 GP interviews (N= 25), four themes were identified from the data: test-requesting behaviour, confidence and challenges in diagnosing disease, access to specialist tests, and guidance and education. Participants’ descriptions of how they request and interpret LFTs varied widely. Concern over missing diagnoses was a common reason for requesting blood tests; patients with mildly abnormal LFTs and those at risk of non-alcoholic fatty liver disease (NAFLD) were a particular cause of concern. GPs saw themselves as generalists, with a reluctance to take on specialist investigations. Guidelines promoted confidence for some clinicians, but others felt that liver disease was too complex to be amenable to simple instructions. Most felt that they did not have access to relevant, focused education on liver disease.

Conclusion

Liver disease is not perceived as a priority in primary care. If GPs are to take on a greater role in identification and management of liver disease, support is needed to promote awareness, knowledge, and confidence.
Concomitant diagnosis of asthma and COPD: a quantitative study in UK primary care
Authors: Nissen Francis , Morales Daniel R , Mullerova Hana , Smeeth Liam , Douglas Ian J , Quint Jennifer K
Published: September 2018

Background

Asthma and chronic obstructive pulmonary disease (COPD) share many characteristics and symptoms, and the differential diagnosis between the two diseases can be difficult in primary care. This study explored potential overlap between both diseases in a primary care environment.

Aim

To quantify how commonly patients with COPD have a concomitant diagnosis of asthma, and how commonly patients with asthma have a concomitant diagnosis of COPD in UK primary care. Additionally, the study aimed to determine the extent of possible misdiagnosis and missed opportunities for diagnosis.

Design and setting

Patients with validated asthma and patients with validated COPD in primary care were identified from the UK Clinical Practice Research Datalink (CPRD) in separate validation studies, and the diseases were confirmed by review of GP questionnaires.

Method

The prevalence of concurrent asthma and COPD in validated cases of either disease was examined based on CPRD coding, GP questionnaires, and requested additional information.

Results

In total, 400 patients with COPD and 351 patients with asthma in primary care were identified. Of the patients with validated asthma, 15% (n = 52) had previously received a diagnostic COPD Read code, although COPD was only likely in 14.8% (95% confidence interval [CI] = 11.3 to 19.0) of patients with validated asthma. More than half (52.5%, n = 210) of patients with validated COPD had previously received a diagnostic asthma Read code. However, when considering additional evidence to support a diagnosis of asthma, concurrent asthma was only likely in 14.5% (95% CI = 11.2 to 18.3) of patients with validated COPD.

Conclusion

A concurrent asthma and COPD diagnosis appears to affect a relative minority of patients with COPD (14.5%) or asthma (14.8%). Asthma diagnosis may be over-recorded in people with COPD.
Creation of a Robust and Generalizable Machine Learning Classifier for Patient Ventilator Asynchrony
Authors: Rehm Gregory , Han Jinyoung , Kuhn Brooks , Delplanque Jean-Pierre , Anderson Nicholas , Adams Jason , Chuah Chen-Nee
Published: September 2018

Background: As healthcare increasingly digitizes, streaming waveform data is being made available from an variety of sources, but there still remains a paucity of performant clinical decision support systems. For example, in the intensive care unit (ICU) existing automated alarm systems typically rely on simple thresholding that result in frequent false positives. Recurrent false positive alerts create distrust of alarm mechanisms that can be directly detrimental to patient health. To improve patient care in the ICU, we need alert systems that are both pervasive, and accurate so as to be informative and trusted by providers.

Objective: We aimed to develop a machine learning-based classifier to detect abnormal waveform events using the use case of mechanical ventilation waveform analysis, and the detection of harmful forms of ventilation delivery to patients. We specifically focused on detecting injurious subtypes of patient-ventilator asynchrony (PVA).

Methods: Using a dataset of breaths recorded from 35 different patients, we used machine learning to create computational models to automatically detect, and classify two types of injurious PVA, double trigger asynchrony (DTA), breath stacking asynchrony (BSA). We examined the use of synthetic minority over-sampling technique (SMOTE) to overcome class imbalance problems, varied methods for feature selection, and use of ensemble methods to optimize the performance of our model.

Results: We created an ensemble classifier that is able to accurately detect DTA at a sensitivity/specificity of 0.960/0.975, BSA at sensitivity/specificity of 0.944/0.987, and non-PVA events at sensitivity/specificity of .967/.980.

Conclusions: Our results suggest that it is possible to create a high-performing machine learning-based model for detecting PVA in mechanical ventilator waveform data in spite of both intra-patient, and inter-patient variability in waveform patterns, and the presence of clinical artifacts like cough and suction procedures. Our work highlights the importance of addressing class imbalance in clinical data sets, and the combined use of statistical methods and expert knowledge in feature selection.
Radiation Hydrodynamics Simulations of Photoevaporation of Protoplanetary Disks. II. Metallicity Dependence of UV and X-Ray Photoevaporation
Authors: Nakatani Riouhei , Hosokawa Takashi , Yoshida Naoki , Nomura Hideko , Kuiper Rolf
Published: September 2018

We perform a suite of radiation hydrodynamics simulations of photoevaporating disks, varying the metallicity in a wide range of

. We follow the disk evolution for over ∼5000 years by solving hydrodynamics, radiative transfer, and nonequilibrium chemistry. Our chemistry model is updated from the first paper of this series by adding X-ray ionization and heating. We study the metallicity dependence of the disk photoevaporation rate and examine the importance of X-ray radiation. In the fiducial case with solar metallicity, including the X-ray effects does not significantly increase the photoevaporation rate when compared to the case with ultraviolet (UV) radiation only. At subsolar metallicities in the range of

, the photoevaporation rate increases as metallicity decreases owing to the reduced opacity of the disk medium. The result is consistent with the observational trend that disk lifetimes are shorter in low metallicity environments. In contrast, the photoevaporation rate decreases at even lower metallicities of

, because dust–gas collisional cooling remains efficient compared to far-UV photoelectric heating whose efficiency depends on metallicity. The net cooling in the interior of the disk suppresses the photoevaporation. However, adding X-ray radiation significantly increases the photoevaporation rate, especially at

. Although the X-ray radiation itself does not drive strong photoevaporative flows, X-rays penetrate deep into the neutral region in the disk, increase the ionization degree there, and reduce positive charges of grains. Consequently, the effect of photoelectric heating by far-UV radiation is strengthened by the X-rays and enhances the disk photoevaporation.
Temperature Response in Living Skin Tissue Subject to Convective Heat Flux
Authors: Das Sanatan , Pal Tilak Kumer , Jana Rabindra Nath , Makinde Oluwole Daniel
Published: September 2018

This paper examines the heat transfer in living skin tissue that is subjected to a convective heating. The tissue temperature evolution over time is classically described by the one-dimensional Pennes' bioheat transfer equation which is solved by applying Laplace transform method. The heat transfer analysis on skin tissue (dermis and epidermis) has only been studied defining the Biot number. The result shows that the temperature in skin tissue is less subject to the convected heating skin compared to constant skin temperature. The study also shows that the Biot number has a significant impact on the temperature distribution in the layer of living tissues. This study finds its application in thermal treatment.
Minimization of Entropy Production in Three Dimensional Dissipative Flow of Nanofluid with Graphene Nanoparticles: A Numerical Study
Authors: Afridi M. Idrees , Qasim Muhammad , Makinde Oluwole Daniel
Published: September 2018

In this study we examined the entropy generation in the three-dimensional flow of nanofluid with graphene nanoparticles. Viscous heating function is added in the energy equation to study fluid frictional effects on entropy generation. The modeled equations are converted into ordinary differential equations using appropriate dimensionless quantities. Shooting technique is implemented to acquire numerical solutions. The numerical solutions are also obtained by using Matlab built-in boundary value solver bvp4c for the validation of our numerical code. The obtained results reveal that they are in good correlation. The obtained numerical results are represented by various graphs and illustrated in great detail.
Flow and Heat Transfer in Nanofluid Flow through a Cylinder Filled with Foam Porous Medium under Radial Injection
Authors: Sharma Mukesh Kumar , Manjeet Choudhary , Makinde Oluwole Daniel
Published: September 2018

The Darcy flow and heat convection in nanofluid through a cylinder filled with a foam porous medium subject to local non-thermal equilibrium (LNTE) condition and uniform radial injection on the outer wall of the cylinder is studied. The momentum and two-energy equations are solved by differential transformation method (DTM) in the form of stream function using similarity variables. The effect on flow and heat transfer of different types of nanofluids and involved physical parameters Prandtl number Pr, Reylond number Re, Darcy number Da, Biot number Bi, Ratio of thermal conductivities Rk, porosity parameter ε, solid volume fraction parameter φ and shape of nanoparticles are analyzed through graphs. The viscous drag force and heat convection at the wall of the cylinder is calculated in terms of non-dimensional skin-friction coefficient and Nusselt number respectively. Decreasing the porosity of foam porous medium causes increment in magnitude of heat transfer rate for both the phases. Spherical shape of nanoparticles transfers more heat in comparison of cylindrical shape nanoparticles. Amongst the nanofluid H2O-Ag, H2O-Cu and H2O-Al2O3 the magnitude of heat transfer for fluid phase Nuf is lowest for nanofluid H2O-Al2O3.
Heat Transfer in Variable Viscosity Micro-Channel Flow of EG-Water/Ag Nanofluids with Convective Cooling
Authors: Makinde Oluwole Daniel
Published: September 2018

Thermal decomposition of a variable viscosity nanofluid containing ethylene glycol (EG)-water mixture with silver (Ag) nanoparticles in a micro-channel with convective heat exchange at the walls is investigated. The model equations for momentum and energy balance are obtained and transformed into a nonlinear boundary value problem using lubrication approximation theory and tackled semi-analytically via perturbation method coupled with Hermite-Padé approximation techniques. EG to water volume ratios examined are 0:100%, 20:80%, 40:60%, 60:40%, 80:20% and 100:0% while the Ag nanoparticles volume fraction utilised are 0%, 5% and 10%. It is found that the critical Eckert number for nanofluid thermal stability and the Nusselt number are enhanced with an increase in the nanoparticles volume fraction while an increase of EG volume ratio in the base fluid lessens the critical Eckert number.
Entropy Analysis of MHD Variable Thermal Conductivity Fluid Flow Past a Convectively Heated Stretching Cylinder
Authors: Das Sanatan , Chakraborty Subhajit , Makinde Oluwole Daniel , Jana Rabindra Nath
Published: September 2018

The present study is related to entropy analysis during magnetohydrodynamic (MHD) boundary layer flow of a viscous incompressible electrically conducting fluid past a stretching cylinder with convective heating in the presence of a transverse magnetic field. The governing boundary layer equations in cylindrical form are simplified by means of appropriate similarity transformations. Numerical solutions with high precision are obtained using Runge-Kutta fourth order scheme with eminent shooting technique. The effects of the pertinent parameters on the fluid velocity, temperature, entropy generation number, Bejan number as well as the shear stress at the surface of the cylinder are discussed graphically and quantitatively. It is examined that due to the presence of magnetic field, entropy generation can be controlled and reduced. Bejan number is plotted to present a comparative analysis of entropy generation due to heat transfer and fluid friction. It is found that Bejan number is an increasing function of Biot number.