bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of Fluid-Fluid Interaction and Flow Through Micro Clearance to Estimate Leakages in a Fuel Injection Pump
Authors: Kamaraj Balasakthivel , Subramanian Shankar C. , Rakkiappan Baskaran
Published: June 2016

Diesel engines require atomized fuel injection inside the combustion chamber for better combustion and reduced emissions, which in turn requires a common rail fuel injection system with higher operating pressure capabilities. But, these requirements lead to increased fuel leakage through the working clearance in the pump to the engine lubrication oil chamber and increased lubrication oil leakage to the fuel side of the pump. The fuel leakage to lubrication oil (FtO) affects the lubrication property of the oil, which in turn affects the life of the lubricated components in the engine. The lubrication oil leakage to fuel (OtF) increases the injector nozzle coking and emission. The leakage flow through the clearance gap was generally studied for 1-dimensional cases by using the Couette–Poiseuille equation obtained from the continuity and the incompressible Navier–Stokes equation. The existing analytical approaches do not consider the fluid interactions/mixing in the 2-dimensional domain. The same is addressed in this study using the numerical simulation tool, Ansys CFX, to estimate the volume flow rate of OtF and FtO considering various design parameters such as diametrical clearance (4–6 μm), cylinder bore taper and piston speed. The leakage of fuel and lubrication oil take place between the working clearance of the piston and the cylinder bore. Pressure and drag effects are two important mechanisms that drive the leakage flow. The transient piston wall speed and the transient pressure at fuel side and lubrication oil side were used as the inputs to the simulation. The grid sensitivity analysis using different grid sizes was done to optimize the grid size. Higher computation time and memory for simulation work was reduced by optimizing the various simulation input parameters. The benchmark problem of Couette-Poiseuille flow was solved and the results were cross-checked with the analytical results. The actual two dimensional flow domain was modeled for the simulation of fluid flow with mixing. The mass and volume flow rate of lubrication oil and fuel were captured at the specified boundary with respect to time. The simulation was carried for various clearance values, clearance taper and speed ranges. The OtF and FtO were found to be increasing with respect to increase in clearance and speed. With this analysis, the sensitivity of the leakage flow rate of fuel and lubrication oil with respect to the important parameters was observed.
Quantification of Cooling Fan Airflow Installation Effects Compared to Plenum-to-Plenum Fan Performance
Authors: Gullberg Peter
Published: June 2016

The classic approach of cooling airflow and cooling performance analysis is to measure component performance (pressure rise, pressure drop, rejected heat etc.) in a Plenum to Plenum test facility. Based on this component data a 1D system model is built and calibrated with full vehicle test data. Full vehicle data is typically acquired from a chassis dynamometer.

This modeling approach assumes each component operates in a similar manner in the rig as in the vehicle. Concerning the fan, several effects are then assumed negligible such as airflow distribution into the fan and also non uniform pressure gradients in the installation aft of the fan.

This paper study and quantify these assumptions and installation effects by the use of 3D CFD correlated to experimental data. The first part will be to demonstrate a correlation between performance test data in a Plenum to Plenum test facility and the corresponding simulation thereof. Based on this correlation the test rig influence can be isolated and removed from the fan performance measurement (based on detailed CFD information). The second part will be to regenerate the fan curve in a truck installation by using 3D CFD and varying the system restriction. This step will also be correlated to Vehicle testing in a chassis dynamometer. The third step will be to compare the in rig fan performance curve to the in vehicle fan performance curve.

The results indicate that the plenum to plenum test rig significantly influence the performance data of the fan in a non-trivial way. Removing the rig influence on the fan performance this paper demonstrates that the fan operates similar in the rig as in the truck.
Optimum Runner Design for Die Casting Using CFD Simulations and Verification With Water-Model Experiments
Authors: Kanazawa Ken’ichi , Yano Ken’ichi , Ogura Jun’ichi , Nemoto Yasunori
Published: June 2016

This study aimed to optimize the design of a runner for high-pressure die casting (HPDC) using computational fluid dynamics (CFD) simulations, and to verify the effectiveness of the runner with water-model experiments. A runner is a part of the flow path through which molten metal enters a product part. As a design problem, we sought to optimize the shape of the runner to minimize air entrainment in the runner and align the flow of molten metal after it passed through the runner. The problem was solved using our proposed nonparametric shape optimization method. The method is based on a genetic algorithm (GA), and directly treats a geometric shape that is comprised of several curves as an individual of a GA in the form of a set of mathematical functions. In addition, the crossover, which is one of the genetic operations, is defined as a weighted summation of two parent curves. Thus, the optimization method can generate optimized shapes with a lot of flexibility. The effectiveness of the optimized shape of the runner was demonstrated with both CFD simulations and water-model experiments using a visualization device for HPDC.
CFD Analysis of Phenomena Attributed to Pigging Run in a Straight Pipeline
Authors: Borregales Manuel A. , Ensalzado Ruben , Asuaje Miguel
Published: June 2016

Growing energy demand requires reliable, safe and long-lasting production systems, including, according to the new legislation, periodic inspections of the pipelines. Currently, design of cleaning tools meant for oil lines, is largely based on experimental information. Big service companies and research centres, built the right tools for their operations, but questions still remain regarding the behaviour of these devices under different flow conditions. In recent years, advances in CFD have allowed to analyse complex phenomena in many industrial applications, participating in technology improvement. The present work proposes a novel 2D CFD methodology to simulate the pigging processes, considering the straight movement of a Pig through a pipeline with a two-phase flow: water-air and oil-gas. The algorithm deforms the grid and re meshes specific domain sections to account for Pig translation relative to the pipe. Three Pig models (Mandrel Pigs, Foam Pigs and Spherical Pigs) were simulated in a horizontal pipe under single-phase liquid flow conditions. Subsequently Pigs were simulated under two-phase flow air-water conditions. Pressure and velocities profiles inside the pipe, and pressure distributions around the Pig were obtained. The result helps to understand the flow behaviour during the pigging processes, providing additional insight on design and operation of these devices.
Similar Region in Electroosmotic Flow Rate for Newtonian and Non-Newtonian Fluids Using Dissipative Particle Dynamics (DPD)
Authors: Zakeri Ramin , Lee Eon Soo
Published: June 2016

In this paper, analysis of electroosmotic flow in Newtonian and non Newtonian fluids in nanochannel with dissipative particle dynamics (DPD) method is presented and our results are validated with analytical solutions. Our aim is that which region or regions, based on the volumetric flow rates, in non-Newtonian fluids are similar with comparison to Newtonian ones in regards to various effective EOF parameters. For numerical simulation, the linearized Poisson Boltzmann for external force calculation is used and DPD method is applied for power law fluids to predict non-Newtonian fluids behavior in electroosmotic in various conditions such as different zeta potential, external electric fields, kh parameter (mainly Debye length and channel height), and flow behavior index. Based on the our results, for certain values of effective parameters, there are regions for volumetric flow rates which both Newtonian and non Newtonian electroosmotic flows have similar behavior while out of these regions, there are obviously significant differences and it is not possible to take Newtonian assumption for these regions. Based on our results validated with analytical solution, simplified assumption of taking non Newtonian fluid as Newtonians ones, in different EOF conditions in most cases, have a clearly inaccuracy and presented method can predict which EOF rates in both cases are correctly similar.
Numerical Investigations on the Aerodynamic Performance of Last Stage Bucket With Part-Span Connector
Authors: Li Bin , Li Jun
Published: June 2016

Long last stage bucket often utilizes part-span connector (PSC) to address various structural issues, however pay little attention to its impact on the aerodynamic performance. In this paper, the aerodynamic performance assessment of last three stages in low pressure steam turbine with PSC on last stage bucket is numerically conducted through solving the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) and k-ε turbulent model based on CFD software ANSYS-CFX. Structured hexahedral grid with reasonable quality is generated for all three stages including last stage bucket with PSC. Three types of grids are used to conduct the grid number independence test. Two kinds of PSCs with different span locations are utilized in last stage bucket. Detailed flow field analysis and comparison of last three stages at designed and off-designed operational conditions without and with two different PSCs are presented. The results show that the two different part-span connectors reduce total-total isentropic efficiency by 0.11% and 0.22%. The mass flow and torque are pushed to upper and bottom as the presence of PSC. The cross flow vortex caused by pressure gradient between pressure and suction side leads to aerodynamic loss.
Turbulence Measurements in the Corner Wall Jet
Authors: Poole Barrett , Hall Joseph W.
Published: June 2016

The corner wall jet is similar to the standard three-dimensional wall jet with the exception that one half of the surface has been rotated counter-clockwise by 90 degrees. The corner wall jet investigated here is formed using a long round pipe with a Reynolds number of 159,000. Contours of the mean and turbulent flow field were measured using hot-wire anemometry. The results indicate that the ratio of lateral to vertical growth in the corner wall jet is approximately half of that in a standard turbulent three-dimensional wall jet.
The Development of the Turbulent Three-Dimensional Wall Jet With and Without a Grid Placed Over the Outlet
Authors: Després Sébastien , Hall Joseph W.
Published: June 2016

The three-dimensional turbulent wall jet has a lateral half-width that is 5 to 8 times greater than its vertical half-height. This has been previously attributed to strong turbulence generated secondary flow caused by the passage of coherent vortex-ring structures formed at the nozzle exit. In order to assess whether the large lateral growth of the jet is tied to these structures, a grid was placed at the nozzle exit to disrupt the shear-layer that produces the vortex rings at the outlet. Here, the jet was formed using a 0.038m round contoured nozzle with an exit Reynolds number of 108,000. The grid has a mesh wire size of 0.2mm with an opening of 1mm giving it a solidity ratio of 0.4. Measurements of the jet with and without the grid were taken using hot-wire anemometry and stereoscopic Particle Image Velocimetry (PIV). The results indicate that the grid delays the lateral growth of the jet and increases its vertical growth. By x/D=40 though, these differences were minimal. The presence of the grid also decreased the mass entrainment and mixing associated with the jet at each downstream location investigated.
A Parallel Offline CFD and Closed-Form Approximation Strategy for Computationally Efficient Analysis of Complex Fluid Flows
Authors: Allphin Devin , Hamel Joshua
Published: June 2016

Computational fluid dynamics (CFD) solution approximations for complex fluid flow problems have become a common and powerful engineering analysis technique. These tools, though qualitatively useful, remain limited in practice by their underlying inverse relationship between simulation accuracy and overall computational expense. While a great volume of research has focused on remedying these issues inherent to CFD, one traditionally overlooked area of resource reduction for engineering analysis concerns the basic definition and determination of functional relationships for the studied fluid flow variables. This artificial relationship-building technique, called meta-modeling or surrogate/offline approximation, uses design of experiments (DOE) theory to efficiently approximate non-physical coupling between the variables of interest in a fluid flow analysis problem. By mathematically approximating these variables, DOE methods can effectively reduce the required quantity of CFD simulations, freeing computational resources for other analytical focuses. An idealized interpretation of a fluid flow problem can also be employed to create suitably accurate approximations of fluid flow variables for the purposes of engineering analysis. When used in parallel with a meta-modeling approximation, a closed-form approximation can provide useful feedback concerning proper construction, suitability, or even necessity of an offline approximation tool. It also provides a short-circuit pathway for further reducing the overall computational demands of a fluid flow analysis, again freeing resources for otherwise unsuitable resource expenditures. To validate these inferences, a design optimization problem was presented requiring the inexpensive estimation of aerodynamic forces applied to a valve operating on a simulated piston-cylinder heat engine. The determination of these forces was to be found using parallel surrogate and exact approximation methods, thus evidencing the comparative benefits of this technique. For the offline approximation, latin hypercube sampling (LHS) was used for design space filling across four independent design variable degrees of freedom (DOF). Flow solutions at the mapped test sites were converged using STAR-CCM+ with aerodynamic forces from the CFD models then functionally approximated using Kriging interpolation. For the closed-form approximation, the problem was interpreted as an ideal 2-D converging-diverging (C-D) nozzle, where aerodynamic forces were directly mapped by application of the Euler equation solutions for isentropic compression/expansion. A cost-weighting procedure was finally established for creating model-selective discretionary logic, with a synthesized parallel simulation resource summary provided.
Method for Characterization of Passive Mechanical Filtration of Particles in Digital Microfluidic Devices
Authors: Dunning Peter D. , Sullivan Pierre E. , Schertzer Michael J.
Published: June 2016

The ability to remove unbound biological material from a reaction site has applications in many biological protocols, such as those used to detect pathogens and biomarkers. One specific application where washing is critical is the Enzyme-Linked ImmunoSorbent Assay (ELISA). This protocol requires multiple washing steps to remove multiple reagents from a reaction site. Previous work has suggested that a passive mechanical comb filter can be used to wash particles in digital microfluidic devices. A method for the characterization of passive mechanical filtration of particles in Digital MicroFluidic (DMF) devices is presented in this work.

In recent years there has been increased development of Lab-On-A-Chip (LOAC) devices for the automation and miniaturization of biological protocols. One platform for further research is in digital microfluidics. A digital microfluidic device can control the movement of pico-to nanoliter droplets of fluid using electrical signals without the use of pumps, valves, and channels. As such, fluidic pathways are not hardwired and the path of each droplet can be easily reconfigured. This is advantageous in biological protocols requiring the use of multiple reagents. Fabrication of these devices is relatively straight forward, since fluid manipulation is possible without the use of complex components.

This work presents a method to characterize the performance of a digital microfluidic device using passive mechanical supernatant dilution via image analysis using a low cost vision system. The primary metric for performance of the device is particle retention after multiple passes through the filter. Repeatability of the process will be examined by characterizing performance of multiple devices using the same filter geometry. Qualitative data on repeatability and effectiveness of the dilution technique will also be attained by observing the ease with which the droplet disengages from the filter and by measuring the quantity of fluid trapped on the filter after each filtration step.
Yawed Effect on Wind Turbine Near Wake
Authors: Ge Yuntian , Wang Xiuling
Published: June 2016

Wind turbines rotation was motivated by the force of wind. In reality, wind doesn’t moving vertically to the wind turbine rotation plane, but in random directions instead. Therefore, the yawed effect has to be taken into consideration when study wind turbine aerodynamic performance. The purpose of this study is to compare the difference between the wind turbine near wake flow with yawed effect and without yawed effect aerodynamically. The research uses CFD technology to simulate the rotation movement and air flow pattern, which is completed in software Ansys Workbench.
Numerical Study of the Fluid Flow in a Cylindrical Hydrocyclone Separator
Authors: Ninahuanca Hans E. Maldonado , Stel Henrique , Morales Rigoberto E. M.
Published: June 2016

This work presents a numerical study on the flow inside a gas-liquid cylindrical hydrocyclone separator. This equipment operates with a free-surface liquid film flow, which is a combination of a centrifugal and a gravitational movement originated by a tangential nozzle. The computational package ANSYS-CFX was employed to simulate the flow using an inhomogeneous Eulerian-Eulerian multiphase flow model with the free surface approach to capture the phases interface. Fluid dynamics is examined for a range of fluid viscosities and flow rates for a single-phase liquid flow at the inlet. The results of the simulations provided basis for the development of a compact mechanistic model for calculating velocity components, film thickness and other variables. This model was derived by analyzing the motion of a fluid element and then by including additional terms that represent the sudden expansion of the flow at the inlet of the cylindrical chamber. Then, the terms included and some model coefficients were calibrated using the numerical results. The outcomes of this work can be used to predict the flow dynamics in a hydrocyclone, which is a fundamental step for more complex evaluations such as estimating the separation efficiency and developing new constructive concepts for the equipment.
Characteristics of Shallow Wakes in an Open Channel
Authors: Nasif G. , Balachandar R. , Barron R. M.
Published: June 2016

A numerical investigation of shallow wake flow in an open channel has been conducted using Detached Eddy Simulation (DES) based on the three-dimensional unsteady Reynolds-Averaged Navier Stokes (RANS) equations with the k-ω SST (shear stress transport) turbulence model. The features of shallow wake flows are strongly dependent on the bed characteristics. Using the λ2 criterion, the important features are identified and the role of coherent structures in the near-bed region is highlighted. Furthermore, a unique feature in the time-averaged flow field referred to as the owl face of the first kind, which consists of a well-defined pair of foci and saddle points, is observed. A three-dimensional structure resulting from a secondary roll-up process, which is horizontally oriented, is observed immediately downstream of the base of the bluff body. Other vortical structures, i.e., a horseshoe vortex and a collar vortex, are found to occur around and next to the bluff body, respectively, in the toe region.
Thickness characterization of atomically thin WSe2 on epitaxial graphene by low-energy electron reflectivity oscillations
Authors: de la Barrera Sergio C. , Lin Yu-Chuan , Eichfeld Sarah M. , Robinson Joshua A. , Gao Qin , Widom Michael , Feenstra Randall M.
Published: June 2016

In this work, low-energy electron microscopy is employed to probe structural as well as electronic information in few-layer WSe2 on epitaxial graphene on SiC. The emergence of unoccupied states in the WSe2–graphene heterostructures is studied using spectroscopic low-energy electron reflectivity. Reflectivity minima corresponding to specific WSe2 states that are localized between the monolayers of each vertical heterostructure are shown to reveal the number of layers for each point on the surface. A theory for the origin of these states is developed and utilized to explain the experimentally observed featured in the WSe2 electron reflectivity. This method allows for unambiguous counting of WSe2 layers, and furthermore may be applied to other two-dimensional transition metal dichalcogenide materials.
Screen-Based Behaviors of Adolescents in Bangladesh
Authors: Khan Asaduzzaman , Burton Nicola W.
Published: June 2016

Background:

The time spent by adolescents in electronic screen-based activities has been associated with obesity and other adverse health outcomes; however, little is known about screen-based behaviors in Asian adolescents. The purpose of this study was to describe the prevalence, patterns, and correlates of recreational screen-based behaviors among adolescents in Bangladesh.

Methods:

A total of 758 students (52% girls), aged 13 to 16 years, from 8 secondary schools of Dhaka city, Bangladesh, completed a survey in which the Adolescent Sedentary Activity Questionnaire was used to collect information on screen time. Total screen time was categorized as ≤2 h/day (low) or >2 h/day (high).

Results:

Approximately 79% of the adolescents had high recreational screen time, with similar values for boys (78%) and girls (80%). Median reported recreational screen time was 4.0 h/day; boys had longer times (4.3 h/day) than girls (3.6 h/day). Multivariable analyses showed that high screen time was more common among boys than girls and was positively associated with commuting to school by car, consumption of fast food ≥3 times/week, having sleep disturbance, and high family income.

Conclusions:

This study identified high rates of recreational screen time among urban adolescents in Bangladesh and specific correlates of prolonged screen time; the results underscore the need to develop pragmatic strategies to reduce sedentariness among adolescents in Bangladesh.
Post-anesthesia AMPA receptor potentiation prevents anesthesia-induced learning and synaptic deficits
Authors: Huang Lianyan , Cichon Joseph , Ninan Ipe , Yang Guang
Published: June 2016

Administration of an AMPAkine prevents long-term deficits induced by repeated neonatal anesthesia.
Expanded Glucose Import Capability Affords Staphylococcus aureus Optimized Glycolytic Flux during Infection
Authors: Vitko Nicholas P. , Grosser Melinda R. , Khatri Dal , Lance Thurlow R. , Richardson Anthony R.
Published: June 2016

Acquisition of numerous virulence determinants affords
Staphylococcus aureus
greater pathogenicity than other skin-colonizing staphylococci in humans. Additionally, the metabolic adaptation of
S. aureus
to nonrespiratory conditions encountered during infection (e.g., hypoxia, nitric oxide, iron chelation) has been implicated as contributing to
S. aureus
virulence. Specifically,
S. aureus
has been shown to ferment glycolytic substrates in nonrespiratory environments encountered within the host. Here, we show that
S. aureus
has acquired unique carbohydrate transporters that facilitate the maximal uptake of host sugars and serve to support nonrespiratory growth in inflamed tissue. The carbohydrate substrates of 11
S. aureus
transporters were identified, and at least four of their genes encode
S. aureus
glucose transporters (
glcA
,
glcB
,
glcC
, and
glcU
). Moreover, two transporter genes (
glcA
and
glcC
) are unique to
S. aureus
and contribute disproportionately to the nonrespiratory growth of
S. aureus
on glucose. Targeted inactivation of sugar transporters reduced glucose uptake and attenuated
S. aureus
in a murine model of skin and soft tissue infections. These data expand the evidence for metabolic adaptation of
S. aureus
to invasive infection and demonstrate the specific requirement for the fermentation of glucose over all other available carbohydrates. Ultimately, acquisition of foreign genes allows
S. aureus
to adopt a metabolic strategy resembling that of infiltrating host immune cells: high glycolytic flux coupled to lactate excretion.

IMPORTANCE
The bacterial pathogen
Staphylococcus aureus
causes a wide range of human infections that are costly and difficult to treat.
S. aureus
differs from closely related commensal staphylococci in its ability to flourish following the invasion of deeper tissue from the skin surface. There,
S. aureus
primarily uses glucose to grow under respiration-limiting conditions imposed by the immune system. It was previously unclear how
S. aureus
thrives in this environment when other
Staphylococcus
species cannot. Our results provide evidence that
S. aureus
has acquired an expanded repertoire of carbohydrate transporters. In particular, four glucose transporters contribute to efficient
S. aureus
growth during infection. Thus,
S. aureus
has evolved to maximize its glucose uptake abilities for enhanced glycolytic flux during tissue invasion. This dependence on glucose acquisition for
S. aureus
virulence may also explain links between serious infectious complications associated with diabetic patients exhibiting elevated blood glucose levels.
Catalytic Subunit 1 of Protein Phosphatase 2A Is a Subunit of the STRIPAK Complex and Governs Fungal Sexual Development
Authors: Beier Anna , Teichert Ines , Krisp Christoph , Wolters Dirk A. , Kück Ulrich
Published: June 2016

The generation of complex three-dimensional structures is a key developmental step for most eukaryotic organisms. The details of the molecular machinery controlling this step remain to be determined. An excellent model system to study this general process is the generation of three-dimensional fruiting bodies in filamentous fungi like
Sordaria macrospora
. Fruiting body development is controlled by subunits of the highly conserved striatin-interacting phosphatase and kinase (STRIPAK) complex, which has been described in organisms ranging from yeasts to humans. The highly conserved heterotrimeric protein phosphatase PP2A is a subunit of STRIPAK. Here, catalytic subunit 1 of PP2A was functionally characterized. The Δ
pp2Ac1
strain is sterile, unable to undergo hyphal fusion, and devoid of ascogonial septation. Further, PP2Ac1, together with STRIPAK subunit PRO22, governs vegetative and stress-related growth. We revealed
in vitro
catalytic activity of wild-type PP2Ac1, and our
in vivo
analysis showed that inactive PP2Ac1 blocks the complementation of the sterile deletion strain. Tandem affinity purification, followed by mass spectrometry and yeast two-hybrid analysis, verified that PP2Ac1 is a subunit of STRIPAK. Further, these data indicate links between the STRIPAK complex and other developmental signaling pathways, implying the presence of a large interconnected signaling network that controls eukaryotic developmental processes. The insights gained in our study can be transferred to higher eukaryotes and will be important for understanding eukaryotic cellular development in general.

IMPORTANCE
The striatin-interacting phosphatase and kinase (STRIPAK) complex is highly conserved from yeasts to humans and is an important regulator of numerous eukaryotic developmental processes, such as cellular signaling and cell development. Although functional insights into the STRIPAK complex are accumulating, the detailed molecular mechanisms of single subunits are only partially understood. The first fungal STRIPAK was described in
Sordaria macrospora
, which is a well-established model organism used to study the formation of fungal fruiting bodies, three-dimensional organ-like structures. We analyzed STRIPAK subunit PP2Ac1, catalytic subunit 1 of protein phosphatase PP2A, to study the importance of the catalytic activity of this protein during sexual development. The results of our yeast two-hybrid analysis and tandem affinity purification, followed by mass spectrometry, indicate that PP2Ac1 activity connects STRIPAK with other signaling pathways and thus forms a large interconnected signaling network.
Delirium with anticholinergic symptoms after a combination of paliperidone and olanzapine pamoate in a patient known to smoke cannabis: an unfortunate coincidence
Authors: Kokalj Anja , Rijavec Nikolina , Tavčar Rok
Published: June 2016

We report a case of delirium with anticholinergic symptoms in a 19-year-old female patient with schizophrenia. On the day the symptoms emerged, the patient received olanzapine long-acting injection and a higher dose of paliperidone. We observed symptoms ranging from confusion to delirium as well as some anticholinergic symptoms. The delirium lasted 24 hours and was managed by intravenous fluid substitution and oral benzodiazepines. Olanzapine pamoate, paliperidone and cannabis are central nervous system (CNS) depressants, and their combination can increase the risks of CNS depression. In this case report, we review the symptoms of delirium in a case of antipsychotic overdose and provide general guidelines for managing these symptoms. We also review possible complications in combined use of cannabis, olanzapine and paliperidone.
Gastric lipoma: an unusual cause of dyspeptic symptoms
Authors: Nasa Mukesh , Choksey Ajay , Phadke Aniruddha , Sawant Prabha
Published: June 2016

Gastric lipomas are rare tumours accounting for 2–3% of all benign gastric tumours. These are usually submucosal in origin but in rare cases may be subserosal in origin. Although a majority of gastric lipomas are asymptomatic and usually detected incidentally, occasionally these can cause abdominal pain, dyspeptic disorders, obstruction, invagination and haemorrhages. In the literature, only 200 cases of gastric lipomas have been reported so far. We report a case of a 56-year-old female with a submucosal symptomatic gastric lipoma presenting with disabling dyspeptic symptoms.
Low socioeconomic status is associated with adverse events in children and teens on insulin pumps under a universal access program: a population-based cohort study
Authors: Shulman Rayzel , Stukel Therese A , Miller Fiona A , Newman Alice , Daneman Denis , Wasserman Jonathan D , Guttmann Astrid
Published: June 2016

Objective

To describe adverse events in pediatric insulin pump users since universal funding in Ontario and to explore the role of socioeconomic status and 24-hour support.

Research design and methods

Population-based cohort study of youth (<19 years) with type 1 diabetes (n=3193) under a universal access program in Ontario, Canada, from 2006 to 2013. We linked 2012 survey data from 33 pediatric diabetes centers to health administrative databases. The relationship between patient and center-level characteristics and time to first diabetic ketoacidosis (DKA) admission or death was tested using a Cox proportional hazards model and the rate of diabetes-related emergency department visits and hospitalizations with a Poisson model, both using generalized estimating equations.

Results

The rate of DKA was 5.28/100 person-years and mortality 0.033/100 person-years. Compared with the least deprived quintile, the risk of DKA or death for those in the most deprived quintile was significantly higher (HR 1.58, 95% CI 1.05 to 2.38) as was the rate of diabetes-related acute care use (RR 1.60, 95% CI 1.27 to 2.00). 24-hour support was not associated with these outcomes. Higher glycated hemoglobin, prior DKA, older age, and higher nursing patient load were associated with a higher risk of DKA or death.

Conclusions

The safety profile of pump therapy in the context of universal funding is similar to other jurisdictions and unrelated to 24-hour support. Several factors including higher deprivation were associated with an increased risk of adverse events and could be used to inform the design of interventions aimed at preventing poor outcomes in high-risk individuals.
Study protocol for screening and diagnosis of fetal alcohol spectrum disorders (FASD) among young people sentenced to detention in Western Australia
Authors: Passmore Hayley M , Giglia Roslyn , Watkins Rochelle E , Mutch Raewyn C , Marriott Rhonda , Pestell Carmela , Zubrick Stephen R , Rainsford Candice , Walker Noni , Fitzpatrick James P , Freeman Jacinta , Kippin Natalie , Safe Bernadette , Bower Carol
Published: June 2016

Introduction

Prenatal alcohol exposure can cause lifelong disability, including physical, cognitive and behavioural deficits, known as fetal alcohol spectrum disorders (FASD). Among individuals with FASD, engagement with justice services is common. Little is known about the prevalence of FASD among young people engaged with the Australian justice system. This study aims to establish FASD prevalence among sentenced young people in detention in Western Australia (WA), and use the findings to develop a screening tool for use among young people entering detention. Translation of these results will guide the management and support of young people in detention and will have significant implications on the lives of young people with FASD and the future of Australian youth justice services.

Methods and analysis

Any sentenced young person in WA aged 10–17 years 11 months is eligible to participate. Young people are assessed for FASD by a multidisciplinary team. Standardised assessment tools refined for the Australian context are used, acknowledging the language and social complexities involved. Australian diagnostic guidelines for FASD will be applied. Information is obtained from young people, responsible adults, teachers and custodial officers. Individualised results and management plans for each young person are communicated to the young person and responsible adult. Prevalence of FASD will be reported and multivariate methods used to identify variables most predictive of FASD and to optimise the predictive value of screening.

Ethics and dissemination

Approvals have been granted by the WA Aboriginal Health Ethics Committee, University of WA Human Research Ethics Committee, Department of Corrective Services, and Department for Child Protection and Family Support. Anonymised findings will be disseminated through peer-reviewed manuscripts, presentations and the media. Extensive consultation with stakeholders (including government agencies, detention centre staff, community service providers, the young people and their families or carers) will be ongoing until findings are disseminated and translated.
Reviewing deaths in British and US hospitals: a study of two scales for assessing preventability
Authors: Manaseki-Holland Semira , Lilford Richard J , Bishop Jonathan R B , Girling Alan J , Chen Yen-Fu , Chilton Peter J , Hofer Timothy P ,   The UK Case Note Review Group
Published: June 2016

Background

Standardised mortality ratios do not provide accurate measures of preventable mortality. This has generated interest in using case notes to assess the preventable component of mortality. But, different methods of measurement have not been compared. We compared the reliability of two scales for assessing preventability and the correspondence between them.

Methods

Medical specialists reviewed case notes of patients who had died in hospital, using two instruments: a five-point Likert scale and a continuous (0–100) scale of preventability. To enhance generalisability, we used two different hospital datasets with different types of acute medical patients across different epochs, and in two jurisdictions (UK and USA). We investigated the reliability of measurement and correspondence of preventability estimates across the two scales. Ordinal mixed effects regression methods were used to analyse the Likert scale and to calibrate it against the continuous scale. We report the estimates of the probability a death could have been prevented, accounting for reviewer inconsistency.

Results

Correspondence between the two scales was strong; the Likert categories explained most of the variation (76% UK, 73% USA) in the continuous scale. Measurement reliability was low, but similar across the two instruments in each dataset (intraclass correlation: 0.27, UK; 0.23, USA). Adjusting for the inconsistency of reviewer judgements reduced the proportion of cases with high preventability, such that the proportion of all deaths judged probably or definitely preventable on the balance of probability was less than 1%.

Conclusions

The correspondence is high between a Likert and a continuous scale, although the low reliability of both would suggest careful measurement design would be needed to use either scale. Few to no cases are above the threshold when using a balance of probability approach to determining a preventable death, and in any case, there is little evidence supporting anything more than an ordinal correspondence between these reviewer estimates of probability and the true probability. Thus, it would be more defensible to use them as an ordinal measure of the quality of care received by patients who died in the hospital.
Multicenter assessment of morbidity associated with cerebral arteriovenous malformation hemorrhages
Authors: Fukuda Keiko , Majumdar Monica , Masoud Hesham , Nguyen Thanh , Honarmand Amir , Shaibani Ali , Ansari Sameer , Tan Lee A , Chen Michael
Published: June 2016

Background

The optimal management strategy for unruptured cerebral arteriovenous malformations (AVMs) is controversial since the ARUBA trial (A Randomized trial of Unruptured Brain AVMs). An accurate understanding of the morbidity associated with AVM hemorrhages may help clinicians to formulate the best treatment strategy for unruptured AVMs.

Objective

To determine the morbidity associated with initial cerebral AVM rupture in patients presenting to tertiary medical centers.

Methods

Retrospective chart reviews from three tertiary academic medical centers were performed for the period between 2008 and 2014. All patients admitted with intracranial hemorrhage due to untreated AVMs were included in this study. Patient-specific variables, including demographics, imaging characteristics, neurologic examination results, and clinical outcome, were analyzed and recorded.

Results

101 Patients met the inclusion criteria. Admission National Institutes of Health Stroke Scale (NIHSS) scores were 0, 1–9, and ≥10 in 26%, 29%, and 45% of patients, respectively. Hematoma locations were subarachnoid, intraventricular, intraparenchymal, and combined in 5%, 11%, 32%, and 52% of patients, respectively. Deep venous drainage was present in 43% of AVMs; AVM-associated aneurysms were present in 44% of patients. Emergent hematoma evacuations were performed in 37% of patients and 8% of patients died while in hospital. At discharge, of those who survived, NIHSS scores of ≥1 and ≥10 were found in 69% and 23%, respectively. At the 90-day follow-up, 34% had a modified Rankin Scale (mRS) score >2. Patients with admission NIHSS score ≥10 had significantly higher rates of midline shift, surgical hematoma evacuation, and follow-up mRS ≥3 (p<0.05).

Conclusions

The morbidity associated with cerebral AVM rupture appeared to be higher in our study than previously reported. Morbidity from AVM rupture should be considered as an important factor, together with variables such as risk of AVM rupture and procedural risk, in determining the optimal treatment strategy for unruptured cerebral AVMs.
Pyrolysis of azetidinones. Part 2. Kinetics and mechanism of thermolysis of β-lactams and β-thiolactams
Authors: Al-Hamdan Nouf S. , Al-Etaibi Alya M. , Al-Bashir Rasha F. , Ibrahim Yahia A. , Al-Awadi Nouria A. , El-Dusouqui Osman M.E.
Published: June 2016

The kinetics of the gas-phase thermolysis reaction of seven β-lactams and their thione analogues were investigated over the temperature range 533–603 K for the β-lactams and 463–542 K for the β-thiolactams. The average values of the energy of activation (Ea) (kJ mol−1) and Arrhenius log A (s–1) were, respectively, 170.8 ± 18.6 and 12.4 ± 1.6 for the lactams and 131.7 ± 18.2 and 11.0 ± 2.0 for the thione analogues. The entropy of activation (ΔS#) was negative for of the substrates and slightly positive for three. The rate constants (k) (s−1) were calculated for 510 K and compared for the two series of azetidinones. The effects of substituents on rates and the novel role played by the C=O and C=S moieties on the relative reactivities of the cyclic amides are rationalized on the basis of a formal retro[2+2]cycloaddition mechanism used earlier to explain the products of the gas-phase thermolysis reaction of the present azetidinones.
Are Faculty Members Ready? Individual Factors Affecting Knowledge Management Readiness in Universities
Authors: Marouf Laila Naif , Agarwal Naresh Kumar
Published: June 2016

Knowledge Management (KM) provides a systematic process to help in the creation, transfer and use of knowledge across the university, leading to increased productivity. While KM has been successfully used elsewhere, universities have been late in adopting it. Before a university can initiate KM, it needs to determine if it is ready for KM or not. Through a web-based survey sent to 1263 faculty members from 59 accredited Library and Information Science programs in universities across North America, this study investigated the effect of individual factors of trust, knowledge self-efficacy, collegiality, openness to change and reciprocity on individual readiness to participate in a KM initiative, and the degree to which this affects perceived organisational readiness to adopt KM. 157 valid responses were received. Using structural equation modeling, the study found that apart from trust, all other factors positively affected individual readiness, which was found to affect organisational readiness. Findings should help universities identify opportunities and barriers before they can adopt KM. It should be a useful contribution to the KM literature, especially in the university context.
Non-linear optical, electrochemical and spectroelectrochemical properties of amphiphilic inner salt porphyrinic systems
Authors: Gros Claude P. , Michelin Clément , Depotter Griet , Desbois Nicolas , Clays Koen , Cui Yan , Zeng Lihan , Fang Yuanyuan , Ngo Hoang Minh , Lopez Colin , Ledoux Isabelle , Nicoud Jean-François , Bolze Frédéric , Kadish Karl M.
Published: June 2016

Three zwitterionic meso-substituted A3B- and AB2C-porphyrins containing one sulfonato alkylpyridinium substituent and three or two alkoxy-substituted phenyl groups were synthesized in good yield and fully characterized as to their physicochemical properties by a variety of techniques. This new series of inner salt donor-acceptor meso-substituted porphyrin derivatives were prepared for possible application as amphiphilic probes for membrane insertion in the area of combined second-harmonic and two-photon fluorescence cellular microscopy. To this end, the linear and nonlinear optical properties of the compounds were characterized, together with their electrochemical and spectroelectrochemical properties in non-aqueous media. The neutral design of such molecules enabled us to determine their second order non-linear properties, both by Electric Field Induced Second Harmonic Generation and Hyper–Rayleigh Scattering. Two-photon absorption cross sections of these dyes were also measured by the two-photon induced fluorescence method. The zwitterionic nature of the inner salt results in very specific solvent-dependent redox-properties, which could be rationalized in terms of solvent-dependent ion-pairing. The overall data electrochemical and photophysical data indicates that these new porphyrinic systems should be good probes for membrane potential sensing.
THE INVESTIGATION OF GHOST FLUID METHOD FOR SIMULATING THE COMPRESSIBLE TWO-MEDIUM FLOW
Authors: LU HAI TIAN , ZHAO NING , WANG DONGHONG
Published: June 2016

In this paper, we investigate the conservation error of the two-dimensional compressible two-medium flow simulated by the front tracking method. As the improved versions of the original ghost fluid method, the modified ghost fluid method and the real ghost fluid method are selected to define the interface boundary conditions, respectively, to show different effects on the conservation error. A Riemann problem is constructed along the normal direction of the interface in the front tracking method, with the goal of obtaining an efficient procedure to track the explicit sharp interface precisely. The corresponding Riemann solutions are also used directly in these improved ghost fluid methods. Extensive numerical examples including the sod tube and the shock-bubble interaction are tested to calculate the conservation error. It is found that these two ghost fluid methods have distinctive performances for different initial conditions of the flow field, and the related conclusions are made to suggest the best choice for the combination.
CFD SIMULATION OF CAPILLARY RISE OF LIQUID IN CYLINDRICAL CONTAINER WITH LATERAL VANES
Authors: LIU XIAOLIN , HUANG YIYONG , LI GUANGYU
Published: June 2016

Orbit refueling is one of the most significant technologies, which has vital strategic meaning. It can enhance the flexibility and prolong the lifetime of the spacecrafts. Space propellant management is one of the key technologies in orbit refueling. Based on the background of space propellant management, CFD simulations of capillary rise of liquid in Cylindrical container with lateral vanes in space condition were carried out in this paper. The influence of the size and the number of the vanes to the capillary flow were analyzed too. The results can be useful to the design and optimization of the propellant management device in the vane type surface tension tank.
THE NUMERICAL STUDY WITH DYNAMIC MESH ON THE POLLUTION CONTROL EFFECT OF OPERATING TABLE PROTECTED BY LAMINAR FLOW SCREEN
Authors: FAN JULI , TIAN LU , JIA XUDONG
Published: June 2016

Transmission of airborne bacteria is the main factor causing surgical site infection (SSI). Horizontal laminar flow screen is a kind of new clean equipment, which can prevent SSI effectively. Numerical simulation is conducted on the pollution control effect of operating table protected by horizontal laminar flow screen. A three-dimensional model is established, discrete phase model (DPM) is used for calculation. Numerical simulation is carried out to evaluate the particle trajectories with the Lagrange approach, and the dynamic mesh is used. Air movement in the case with and without people’s walking is analyzed. As a result, people’s walking would not affect the distribution of pollutants at the key area of the operating table, the vertex caused by the walking person does little influence on flow field of the whole operating room and the influence area is about 0.24m to 0.75m around the walking person. The protective effect of pollutants with horizontal laminar flow screen for the key areas of operating table is excellent. This work provides references for the study on the depuration of operating room or other occasion.