bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Muscle-Powered Soft Robotic Bi-VAD for Long-Term Circulatory Support
Authors: Han Jooli , Kubala Matthew , Trumble Dennis R.
Published: July 2018

Congestive heart failure (CHF) remains one of the most costly diseases in the industrialized world, both in terms of healthcare dollars and the loss of human life. Despite great strides made in the treatment of CHF using mechanical ventricular assist devices (VADs), several longstanding difficulties associated with pumping blood continue to limit their long-term use. Among the most troublesome have been the increased risk of infection associated with the use of percutaneous drivelines and the persistent risk of clot formation at the blood-device interface. Development of a completely self-contained, non-blood-contacting VAD for long-term use would therefore be an important advance in circulatory support technology. Toward that end, we have developed a muscle-powered co-pulsation VAD (Figure 1) that avoids both these problems by using an internal muscle energy converter (MEC) to drive a non-blood-contacting direct cardiac compression sleeve (DCCS) for long-term circulatory support.
Pneumatic Piston Stepper Motor: An Enabler for MRI-Guided Robotic Interventions
Authors: Boland Brian L. , Xu Sheng , Wood Bradford , Tse Zion Tsz Ho
Published: July 2018

Magnetic resonance (MR) imaging (MRI) has become the preferred method for medical diagnosis due to high resolution images and lack of ionizing radiation. Recently, the potential for using MRI to obtain real-time image feedback for targeted therapeutic procedures such as targeted biopsies and injections has been explored [1]. Some devices designed for intra-MRI use exist and more such devices are currently being developed and researched. Procedures often require precise positional targeting, such as injections and biopsies, and an MRI safe controlled-motion stepper motor is an ideal choice for actuating these mechanical devices. Some such drivers have been developed, but for various reasons, none are considered to be the standard for MRI use at this time. Therefore, a new design combining certain aspects of previous motors has been developed, making use of newer three-dimensional (3D) printers with extreme accuracy. Presented is a small, low-cost plastic four-cylinder piston stepper motor which is actuated by pressurized air. Connected to a plastic gearbox, this motor is capable of driving a rotational shaft at torques of up to 20 N·mm by increments of 3.6 degrees.
A Smartphone Stethoscope and Application for Automated Identification of Innocent Still’s Murmur
Authors: John Titus , Doroshow Robin W. , Shekhar Raj
Published: July 2018

Primary care physicians (PCPs) often lack the skills to distinguish the common innocent Still’s murmur from far less frequent but potentially serious pathological heart murmurs. This leads to approximately 800,000 children being referred to pediatric cardiologists each year for evaluation of heart murmurs in the United States [1–2]. The murmur is ultimately diagnosed as an innocent Still’s murmur in approximately 78% of these children (Children’s National Health System data). These unnecessary referrals and associated tests cost the healthcare system over half a billion annually, and are a source of avoidable anxiety for children and families while waiting to see a pediatric cardiologist.
Flexible Template to Assist MRI-Guided Biopsy on Prostate Cancer
Authors: Li Rui , Bakhutashvili Ivane , Xu Sheng , Wood Bradford , Tse Zion T. H.
Published: July 2018

The proposed 3D-printed template is a low cost and disposable devise which makes innovative registration-free procedure possible. The accuracy of the targeting is greatly improved due to its MRI-visible feature and precise design of needle insertion channels.
Temperature Monitoring With Zero Heat Flux Technology in Comparison With Thermocouple Needle Probe During Selective Hypothermia
Authors: Fazel Bakhsheshi Mohammad , Keenliside Lynn , Lee Ting-Yim
Published: July 2018

Hypothermia (brain temperature < 35°C) shows great promise to minimize neural damage in patients with cardiopulmonary arrest and traumatic head injuries.[1, 2] However, cooling the whole body below 33–34°C can induce severe complications.[3] Arrhythmia, infection and primary coagulopathy are the most commonly noted complications.[3] We have developed a Selective Brain Cooling (SBC) approach which can be initiated early after injury, induces rapid cooling and maintains the target brain temperature over an extended period of time before slowly rewarming without significantly affecting the core body temperature.[4] In our experiments, brain temperature was measured invasively by inserting a thermocouple probe into the brain parenchyma, which measured brain temperature accurately but is invasive, making it unsuitable for most patients. Invasive intracranial probe also can have complications such as intracranial hemorrhage or hematoma and infection.[5] Accordingly, the clinical adaptation of our SBC technique requires a reliable, non-invasive and accurate method for measuring local brain temperature so that cooling and rewarming rate can be controlled during targeted temperature management.
Coronary Stenosis Measurements Using K-Means Clustering
Authors: Akhbardeh Farhad , Demirel Hasan
Published: July 2018

Medical imaging is one of common area that nowadays researchers uses human body images for clinical or medical science [1] [2]. Currently most of the diagnoses are performed by doctors after manual inspection of real time frames of the video generated by the respective medical imaging systems. In this paper, we propose to use digital image processing techniques in detection and categorization of the clogs in the arteries (stenosis/blockage) by using the frames generated from the X-ray angiography [3][4]. Utilized image pre-processing methods includes selecting a line of Interest (LOI) on blocked vessel and further selection of the region of interest (ROI) on that area, then automatically cropping the region of interest followed by Gaussian filtering for smoothing. In the post processing, three alternative methods are proposed to measure the stenosis in the vessel. The first method applies thresholding (Local) to extract the vessel of interest. The extracted vessel is analyzed for the calculation of the stenosis in percentage [5]. The second method utilizes segmentation (both edge-based and region-based) of the vessel tissue over the extracted pixels of ROI. The final method uses K-means clustering to differentiate between the vessel regions and non-vessel regions. Among the proposed methods K-means clustering based method outperforms the thresholding and segmentation methods.
Design and Experimental Validation of a Radial Air Turbine Wheel of an Air Starter for Fighter Aircraft Application
Authors: Singh Amar , Shibu K. Joseph , Mishra R. K.
Published: July 2018

A radial Air Turbine Wheel (ATW) designed to operate at 60000 rpm has been analysed for LCF and HCF life. Frequency and mode shape evaluation including blade disk coupling at different nodal diameters is carried out to obtain a speed range without undesirable resonance conditions. Harmonic analysis evaluated the effects of forced response during resonance. Structural integrity during transient has been analysed and found free from set in of any transient effects. The ATW has been fabricated through forging route and its structural integrity has been validated at its operating speed as well as 15% and 22% overspeeds. Satisfactory performance during these tests without any distress has demonstrated the adequacy of design and qualification of the turbine wheel for fitment in the air starter. The turbine wheel is fitted in an air starter unit which was then successfully performed consistently over 100 start cycles before cleared for aircraft application.
Turbojet Engine Performance Tuning With a New Map Adaptation Concept
Authors: Misté Gianluigi Alberto , Benini Ernesto
Published: July 2018

Gas turbine off design performance prediction is strictly dependent on the accuracy of compressor and turbine map characteristics. Experimental data regarding component maps are very difficult to find in literature, since it is undisclosed proprietary information of the engine manufacturers. To overcome this limitation, gas turbine engineers use available generic component maps and modify them to reach the maximum adherence with the experimental measures.

Different scaling and adaptation techniques have been employed to this aim; these methodologies are usually based upon analytic regression models which minimize the deviation from experimental data. However, since these models are built mainly for a specific compressor or turbine map, their generalization is quite difficult: in fact, regression is highly shape-dependent and therefore requires a different model for each different specific component.

This paper proposes a solution to the problem stated above: a new method for map adaptation is investigated to improve steady-state off design prediction accuracy of a generic gas turbine component. The methodology does not employ analytical regression models; its main principle relies in performing map modifications in an appropriate neighborhood of the multiple experimental points used for the adaptation. When using gas turbine simulation codes, component maps are usually stored in a data matrix and are ordered in a format suitable for 2-D interpolation. A perturbation of the values contained in the matrix results in component map morphing. An optimization algorithm varies the perturbation intensity vector in order to minimize the deviation between experimental and predicted points.

The adaptation method is integrated inside TSHAFT, the gas turbine prediction code developed at the University of Padova. The assessment of this methodology will be exposed by illustrating a case study carried out upon a turbojet engine.
A Study on Coatability of Linz-Donawitz (LD) Slag by Plasma Spraying Route
Authors: Pati Pravat Ranjan , Satapathy Alok
Published: July 2018

Linz-Donawitz slag (LDS) is a major solid waste generated in huge quantities during steel making. Although a number of ways for its utilization have been suggested in the past, its potential as a possible erosion resistant coating material has not yet been explored. This work is an attempt to develop functional coatings of this LDS on metal substrates by plasma spraying. The coating deposition is carried out using an 80 kW atmospheric plasma spray system working in non-transferred arc mode at different torch input powers (10–24 kW). Coatings are characterized in terms of their thickness and adhesion strength. Coating deposition efficiency is calculated to assess the coatability and XRD is done to ascertain the phases present in the coating. It is found that the operating power levels of the plasma torch affect the adhesion strength, deposition efficiency and mean thickness of the coatings. Solid particle erosion trials, as per ASTM G76 test standards, are conducted on the coating samples following a well planned experimental schedule based on Taguchi design of experiments. This work reveals that LDS is eminently coatable with deposition efficiency as high as 33% and can be gainfully used as a cost-effective wear resistant coating material.
Metal Temperature Correlations in Tilting Pad Journal Bearings
Authors: Thorat Manish R. , Pettinato Brian C. , De Choudhury Pranabesh
Published: July 2018

Predicted and measured bearing metal temperatures of tilting-pad journal bearings are examined. All bearings are a five-pad design with load-between-pad orientation. The two loaded pads in each bearing are instrumented with an RTD. Bearing pad metal temperatures are measured as a part of the ISO 10439 (API 617) mechanical test requirement. Bearing pad metal temperatures are predicted using thermoelastohydrodynamic (TEHD) analysis method. One particular bearing size: 4 inches (101.6 mm) diameter and 1.54 inches (39.12 mm) axial length is examined with respect to tolerance range influence on predicted pad metal temperatures including effect of bearing assembled clearance and preloads. A range of loads and speeds are investigated. Temperature variation observed for this bearing size is compared against variation in measured temperature data for three other bearing sizes (bearing sizes denoted by diameter × axial length), 2.95 inches (74.9 mm) × 1.02 inches (25.9 mm), 6 inches (152.4 mm) × 3 inches (76.2 mm), and 8 inches (203.2 mm) × 7 inches (177.8 mm).
Pre-Emptive Rotor Blade Damage Identification by Blade Tip Timing Method
Authors: Guru Siddhartha S. , Shylaja S. , Kumar Sunil , Murthy Ramesh
Published: July 2018

The Blade Tip Timing (BTT) method uses the differential arrival timings of the blades at case-mounted sensors to effectively characterize the vibrations of all blades in a rotor. This paper studies the use of the BTT method for preemptive prediction of rotor blade damage; through a careful monitoring of blade natural frequencies in conjunction with the blade tip position during an engine test. In the current study, the low pressure turbine stage of a developmental aero engine is instrumented with a combination of eddy current and optical sensors located circumferentially on the casing. This instrumentation effectively captures the engine order resonances of interest for the blade bending mode. During one of the normal engine tests, one of the blades in the LPT stage suddenly showed a drop in natural frequency beyond the allowable scatter and an abrupt change in the blade tip position. As the engine test was continued further, this drop in blade natural frequency and change in blade tip position progressively increased towards blade failure limits. Suspecting a propagating crack in the particular blade, the test was aborted and the engine was withdrawn for detailed inspection. Inspection of the rotor blades confirmed the presence of significant aero-foil crack in the suspect blade.
Health Monitoring of Gear Elements Based on Time-Frequency Vibration by Support Vector Machine Algorithms
Authors: Bordoloi D. J. , Tiwari Rajiv
Published: July 2018

Health monitoring of a gear box has been attempted by the support vector machine (SVM) learning technique with the help of time-frequency (wavelet) vibration data. Multi-fault classification capability of the SVM is suitably demonstrated that is based on the selection of SVM parameters. Different optimization methods (i.e., the grid-search method (GSM), the genetic algorithm (GA) and the artificial bee colony algorithm (ABCA)) have been performed for optimizing the SVM parameters. Four fault conditions have been considered including the no defect case. Time domain vibration signals were obtained from the gearbox casing operated in a suitable speed range. The continuous wavelet transform (CWT) and wavelet packet transform (WPT) are extracted from time domain signals. A set of statistical features are extracted from the wavelet transform. The classification ability is noted and compared against predictions when purely time domain data is used, and it shows an excellent prediction performance.
Fine Temperature Measurement and Fabrication of On-Chip Whispering-Gallery Mode Micro-Sensors
Authors: Frenkel Matthew , Avellan Marlon , Guo Zhixiong
Published: July 2018

Whispering-Gallery mode based optical micro-devices have been demonstrated to have extremely high sensitivity to changes in local temperature owing to their high quality factors and frequency-based measurements. In this paper, we first examine different fabrication techniques for integrating whispering-gallery mode sensors directly onto heating components to realize on-chip in-situ dynamic temperature measurements and monitoring. The merits and drawbacks of each fabrication technique are discussed. Then, the capability of the fabricated on-chip micro-sensors to perform precise real-time thermal measurements was tested, and the findings are discussed. Finally, the advantages of such on-chip sensors are established through heat transfer analysis.
On the Influence of Nanoparticle Shapes for Nanofluids Flow Behaviors by Molecular Dynamics Simulation
Authors: Cui Wenzheng , Bai Minli , Lv Jizu , Weng Peng , Hu Chengzhi , Li Xiaojie
Published: July 2018

Understanding how the nanoparticles influence flow behavior of nanofluids is important for revealing mechanism of heat transfer enhancement by using nanofluids. The aim of this work was to study the microscopic change in base fluid and micro-motion of nanoparticles due to Brownian motion by molecular dynamics simulation. The present work established shearing flow simulation models considering different shapes of nanoparticles. Velocity distribution and number density distribution of fluid, and angular velocity components and translational velocity components of nanoparticles were statistically analyzed. The results of velocity distribution and number density distribution showed that adding nanoparticles reduces flow boundary layer and causes uneven distribution of mass; and the results for angular velocity components and translational velocity components of nanoparticles showed that nanoparticles rotate fast in the fluid, and vibrate irregularly. The present study suggests that adding nanoparticles causes microscopic change for base fluid including reducing thickness of flow boundary layer and uneven density distribution in fluid. In addition, the micro-motions of nanoparticles including rotation and vibration due to Brownian motion strengthen micro-flow effect and momentum transfer in nanofluids. Furthermore, by comparing motion behaviors of nanoparticles in different shapes the present work reveals that shapes of nanoparticles influence deeply flow behavior of nanofluids.
Inertial Microfluidics for Separation and Detection of Tumor Cells
Authors: Sun Jiashu
Published: July 2018

We report on the development of a curved microfluidic channel that allows rapid and continuous size-based rare tumor cell separation from blood in a label-free manner by exploiting the hydrodynamic effects. The separated tumor cells are trapped and enriched on an integrated polycarbonate filter glued on top of the outlet reservoir of microchannels. CK19 mRNA of MCF-7 cells are detected by loop-mediated isothermal amplification (LAMP).
Numerical Study of Solar Photovoltaic/Thermal (PV/T) Hybrid Collector Using Nanofluids
Authors: Mittal Tarun , Saroha Siddharth , Bhalla Vishal , Khullar Vikrant , Tyagi Himanshu , Taylor Robert A. , Otanicar Todd P.
Published: July 2018

The commonly used methods to harness solar energy are solar thermal and solar photovoltaic (PV). A new category photovoltaic/thermal (PV/T) hybrid combines these two technologies, and achieves higher combined efficiency. The challenge is to keep the operating temperature of the PV low and at the same time not compromise on the temperature of the thermal cycle. Various designs of PV/T hybrids (both flat plate and concentrated) have already been proposed which utilize air or water to remove the heat from PV cells in order to enhance the overall efficiency of PV/T hybrid collector. Recent papers have showed that nanofluids can be used as an optical filter to filter the required wavelength range (equivalent to the band gap of the PV cell) from solar spectra. Thus, the heating of PV cells can be significantly reduced and higher overall efficiencies can be achieved using selective absorption by nanofluids. In this study, a new design of a PV/T hybrid collector was proposed and two nanofluid filters that can be used with Silicon (Si) PV cells were identified and corresponding thermal and overall efficiencies of PV/T hybrid collector were calculated.
Multiscale Study of Gas Slip Flows in Nanochannels
Authors: To Quy Dong , Pham Thanh Tung , Brites Vincent , Léonard Céline , Lauriat Guy
Published: July 2018

In this paper, a multi-scale modeling of the anisotropic slip phenomenon for gas flows is presented. The analysis is carried out by using two principal computational methods: the Density Functional Theory and the Molecular Dynamics approach. The ab-initio method is used to examine the interaction between the Pt-Ar gas-wall couple, and to determine the effective potential. The potential is then implemented into a MD code in order to simulate beam scattering experiments and to calculate the accommodation coefficients. The results are used to model the effective interaction for isotropic or anisotropic surfaces. Further MD simulations, based on the effective gas-wall model for anisotropic surfaces, are conducted. The slip effects are quantified numerically and compared with simplified theoretical models, also derived in this paper.
Viscous Dissipation Effect on Entropy Generation of Nanofluid Flow in Microchannels
Authors: Ting Tiew Wei , Hung Yew Mun , Guo Ningqun
Published: July 2018

An analytical study of the viscous dissipation effect on entropy generation of forced convection of water-alumina nanofluid in a circular microchannel subjected to exponential wall heat flux is reported. Closed form solutions of the temperature distributions in the streamwise direction for the models with and without viscous dissipation term in the energy equation are obtained. The two models are compared by analyzing their relative deviations in entropy generation for different Reynolds number and nanoparticle volume fraction. The incorporation of viscous dissipation prominently affects the temperature distribution and consequently the entropy generation. The increase in the entropy generation is mainly attributable to the increase in the fluid friction irreversibility. The addition of nanoparticle increases the effective thermal conductivity and viscosity of nanofluid which induces escalation in the heat transfer and fluid friction irreversibilities, respectively. By taking the viscous dissipation effect into account, the exergetic effectiveness for forced convection of nanofluid in microchannels attenuate with increasing nanoparticle volume fraction. From the aspect of the second law of thermodynamics, the widespread conjecture that nanofluids possess advantage over pure fluid associated with higher overall effectiveness is invalidated.
Local Experimental Heat Transfer of Single-Phase Pulsating Flow in a Square Mini-Channel
Authors: Mehta Balkrishna , Khandekar Sameer
Published: July 2018

Disturbing the flow with a particular pulsating frequency alters the thermal and hydrodynamic boundary layer thus affecting the inter-particle momentum and energy exchange. Due to this enhanced mixing, augmentation in the heat transfer is expected. Obviously, the parameters like pulsating frequency vis-à-vis viscous time scales and the imposed pulsating amplitude will play an important role in the enhancement of the heat transfer. Several numerical heat transfer and fluid flow studies on pulsating flows have been reported in the literature but the conclusions are not coherent. Lack of experimental study in hydrodynamics as well as in heat transfer of laminar pulsating flows attracts to revisit this problem especially, in mini-channels. Technological developments in measurement and instrumentation have enabled to experimentally investigate the thermo-hydrodynamic study of laminar pulsating flows in mini-channels as an augmentation technique for heat transfer. In this work, we have undertaken the experimental measurements of heat transfer of single-phase laminar pulsating flow in square mini-channel of cross-section 3 mm × 3 mm. The study is done at two different pulsating frequency 0.05Hz and 1Hz (Womersley number, Wo = 0.8 and 3.4 respectively). These two values are chosen because velocity profile exhibits different characteristic for Wo > 1 (annular effect, i.e., peak velocity near the wall) and Wo < 1 (conventional parabolic profile). The heat transfer study has been done in a square channel of made on polycarbonate sheet with one side heating. Heater (made of SS, 70 microns thin strip, negligible thermal inertia) itself is one of the walls of the square channel making constant heat flux thermal condition and its instantaneous temperature is measured by using pre-calibrated InfraRed camera. Fluid bulk mean temperature has been determined by energy balance and one K-type thermocouple is also placed in the fluid at the outlet cross-section. By using these temporal data, space averaged instantaneous Nusselt number has been obtained. It is observed that for measured frequency range, the overall enhancement in the heat transfer is not attractive for laminar pulsating flow in comparison to steady flow of same time-averaged flow Reynolds number. It is found that the change in species transport is either marginal or highly limited and is primarily occurring in the developing length of the channel/ plate. Enhancement of species transport due to such periodic pulsatile internal flows, over and above the non-pulsatile regular flow conditions, is questionable, and at best, rather limited.
Relationships Between Hematocrit and Sample Flows on Lab-on-a-Chip
Authors: Pramuanjaroenkij Anchasa , Wongpanit Kannika , Phonong Gorrawis , Chaiburi Burin , Kakaç Sadık
Published: July 2018

In this work, the reusable Lab-on-a-Chip or LOC was fabricated and developed to reduce its investment cost and to ease its operations. A sandwiched acrylic set was chosen to assemble the PDMS LOC which was aimed to investigate biological samples, especially the samples from animals. Chicken and sheep blood were chosen as the samples to implement two-phase flows with different red-blood-cell shapes. The chicken blood flow represented the viscous two-phase flow with the oval shape particles while the sheep blood flow represented the inadhesive samples with the round particles. The LOC electrodes from different materials as the sputtered nickel plate, the aluminium foil, the copper plate, and the gold foil were examined. Ratios between the anticoagulant solution and the biological samples were studied to find their effects on sample velocities and to find the best image to characterize the RBC flow behaviors. Since it was hard to characterize the particle flow in the inadhesive flows, the result pictures were analyzed and presented in terms of color intensities per unit area by using a computer program called “ImageJ”. The sheep-blood-flow results were validated with the hematology results which were the hematocrits to find their relationships between the hematocrits and the RBC flows. Among different LOC electrodes, the sputtered nickel electrodes were the most suitable electrodes in this current application. We found that the suitable anticoagulant-sample ratios for chicken and sheep samples were 5:1 and 1:1 by volume, respectively. The normal-health-condition sheep with the standard hematocrits higher than 28% showed the average-different-color intensities per unit area between cathode and anode at 39.485 pixels per unit area while the lower standard hematocrit samples, the hematocrits were lower than 28%, showed the average-different-color intensities at 14.641 pixels per unit area, the lower intensity the lower hematocrit. So the LOC coupled with “ImageJ” exhibited their capabilities to investigate the sheep blood conditions, especially, this coupled technique consumed less time than the traditional hematology process.
CFD-Analysis of Single Rectangular Microchannel Under Forced Convection Heat Transfer Condition for Laminar Flow
Authors: Kamble D. A. , Gawali B. S.
Published: July 2018

This paper describes the CFD analysis of single rectangular microchannel for hydraulic diameter 319 μm. While CFD analysis the Nusselt number observed is 4 to 5 with different Reynolds Number variation for flow rate of 0.001 kg/sec to 0.012 kg/sec. The current work describes CFD analysis of single microchannels for length of 50 mm with water as a fluid medium with laminar flow. Computational Fluid dynamics analysis of Single rectangular microchannel Single rectangular microchannel of 319 μm hydraulic diameter is analyzed to study the flow characteristics in the inlet, microchannel test section and outlet test section with ANSYS CFX-11 for pressure drop, temperature drop, velocity counter of single micro-channel. For analyzing the weather the turbulence is created at inlet part of the microchannel a pressure drop analysis is carried for flow rate of 0.012 kg/sec with heat input 5.33 watt/cm2 under laminar flow consideration. For analyzing the temperature profile across microchannel a for flow rate of 0.012 kg/sec with heat input 5.33 watt/cm2 under laminar flow is considered.. For single microchannel the temperature rise of water is in range of 1 °K to 2 °K at center plane of microchannel. It is found that at leading edges or leaving edge the temperature rise in water is higher as compare to entering edge of microchannel. It is due to while entering to leaving of water particles in microchannel it collapse each other and try to increasing friction along each other so at outlet or leading edge the temperature rise is seen higher as compare to in let portion of single microchannel.
Drift of Piles Subjected to Cyclic Lateral Loading From a Varying Direction: System vs. Soil Element Behavior
Authors: Rudolph Christina , Grabe Jürgen , Bienen Britta
Published: July 2018

Offshore monopiles are usually designed using the p-y method for cyclic loading. While the method works for static loading, it was not developed for high numbers of cycles. Since the turbines are highly sensitive towards tilting, cyclic loading must be considered. The static results should therefore be combined with results from cyclic model tests with a high number of cycles to account for the accumulation of displacement or rotation during the lifetime of these structures. These model tests can underestimate the accumulation, however, as it has recently been shown that a change of loading direction can increase the accumulation considerably. These results have been verified using small scale modeling and centrifuge testing. The results from modeling the full problem of a laterally loaded pile are compared here with results from cyclic simple shear tests with a change of shearing direction during the cyclic loading. For these tests, a newly developed apparatus is used. This allows further insight into the question how a soil can “retain a memory” of its loading history.
Continuous Characterisation of Near-Surface Soil Strength
Authors: Cocjin Michael , White David , Gourvenec Susan
Published: July 2018

A sound understanding of near-surface soil strength is essential for the accurate prediction of the response of structures laid on or shallowly embedded in the seabed. However, characterisation of the uppermost region of the seabed, which is typically very soft and at a low-stress state, is extremely challenging. This paper demonstrates a novel technique for characterising the in situ undrained shear strength of near-surface soils using a newly-developed pile penetrometer. The pile penetrometer is vertically embedded into the near-surface soil and is driven laterally. A simple calculation of the resistance mobilised over the embedded depth of the pile penetrometer is presented along with its application to the continuous measurement of spatial variation in near-surface strength in virgin and disturbed regions of soil.
Large Deformation FE Analyses of Cone Penetration in Single Layer Non-Homogeneous and Three-Layer Soft-Stiff-Soft Clays
Authors: Ma Hongliang , Zhou Mi , Hu Yuxia , Hossain Muhammad Shazzad
Published: July 2018

Continuous profiles from in-situ penetrometer tests are now identified as essential for site specific soil investigation as part of designing offshore structures in deep and ultradeep waters and in highly layered seabed conditions. This paper describes the results from large deformation FE (LDFE) analysis undertaken to provide insight into the behavior of cone penetrometer penetrating through single layer non-homogeneous clays and three-layer uniform soft-stiff-soft clays. For the smooth cone penetration in non-homogeneous clays, the soil strength non-homogeneity factor was shown to have insignificant effect on the cone bearing capacity factor. However, for the rough cone, the bearing capacity factor in non-homogeneous clay was about 10∼12% lower than that in uniform clay. Bearing capacity factors for smooth and rough cones were also similar for non-homogeneous clay. For cone penetration in stratified soft-stiff-soft clays, a minimum layer thickness of 20 diameters was required to mobilise the full resistance of the stiff layer. The corresponding soil flow mechanisms are also discussed linking directly to the profile of penetration resistance.
Modeling the effect of palate shape on the articulatory-acoustics mapping
Authors: Bakst Sarah , Johnson Keith
Published: July 2018

Articulatory variability is reduced for people with flatter palates [Bakst and Lin (2015). Proceedings of the 18th International Congress of Phonetic Sciences; Brunner, Fuchs, and Perrier (2009). J. Acoust. Soc. Am. 125(6), 3936–3949]. Brunner, Fuchs, and Perrier [(2009). J. Acoust. Soc. Am. 125(6), 3936–3949] hypothesized that this is because the mapping between articulation and acoustics depends on palate depth. Articulatory synthesis was used with three different palate shapes to generate productions of /r/. The parameter spaces of the articulatory synthesizers were searched for vocal tract configurations that result in low F3 (the hallmark acoustic cue for /r/). Palate shape influences not only the sensitivity of the articulatory-acoustic mapping, but also the effect of each individual articulatory parameter on F3.
Rheo-NMR of transient and steady state shear banding under shear startup
Authors: Al-kaby Rehab N. , Jayaratne Jayesha S. , Brox Timothy I. , Codd Sarah L. , Seymour Joseph D. , Brown Jennifer R.
Published: July 2018

In this work, shear band formation following shear startup as a function of flow protocol is investigated in the wormlike micelle (WLM) system of 6 wt. % cetylpyridinium chloride and sodium salicylate in 0.5M NaCl brine in a Couette Rheo-nuclear magnetic resonance (NMR) shear cell. Many applications using WLM solutions occur under time dependent conditions; however, shear banding under time dependent flow protocols is not as well characterized. 1D velocity profiles across the 1 mm fluid gap are recorded every 1 s after shear startup using Rheo-NMR velocimetry and used to evaluate shear banding characteristics, including the shear rates in the low and high shear band, the interface position, and the apparent wall slip as a function of time. The velocity, and therefore the shear banding characteristics, exhibits large temporal fluctuations following an abrupt startup to 12 s−1. Data were decomposed into an average and fluctuation about the average in order to extract the characteristic time scales for the transition of the flow from transient to steady state. In addition, the Fourier transform of time autocorrelation functions was used to quantify the fluctuation frequencies themselves, which are related to the apparent slip at the inner rotating wall and the presence of flow instabilities. This analysis has the potential to allow a 1D measurement to provide information about the 3D flow. Shear startup experiments were also performed for flow protocols with and without preshear. Preshear resulted in different magnitudes of the timescales and a shift in the frequencies of the fluctuation of all shear banding characteristics, emphasizing the importance of shear history on the flow behavior of these WLM solutions.
Exploring a naturally tailored small molecule for stretchable, self-healing, and adhesive supramolecular polymers
Authors: Zhang Qi , Shi Chen-Yu , Qu Da-Hui , Long Yi-Tao , Feringa Ben L. , Tian He
Published: July 2018

A supramolecular polymer with integrated properties is readily obtained from a natural small molecule.
Algicidal Activity of Novel Marine Bacterium Paracoccus sp. Strain Y42 against a Harmful Algal-Bloom-Causing Dinoflagellate, Prorocentrum donghaiense
Authors: Zhang Fuxing , Ye Qian , Chen Qiuliang , Yang Ke , Zhang Danyang , Chen Zhangran , Lu Shasha , Shao Xueping , Fan Yongxiang , Yao Luming , Ke Lina , Zheng Tianling , Xu Hong
Published: July 2018

P. donghaiense
is one of the most common dinoflagellate species that form harmful algal blooms, which frequently cause serious ecological pollution and pose health hazards to humans and other animals. Screening for bacteria with high algicidal activity against
P. donghaiense
and studying their algicidal processes and characteristics will contribute to an understanding of their algicidal effects and provide a theoretical basis for preventing algal blooms and reducing their harm to the environment. This study reports the algicidal activity and characteristics of
Paracoccus
against
P. donghaiense
. The stability of the algicidal activity of
Paracoccus
in different environments (including different temperature, pH, and sunlight conditions) indicates its potential for use in the control of
P. donghaiense
blooms.
Fructophilic Lactic Acid Bacteria, a Unique Group of Fructose-Fermenting Microbes
Authors: Endo Akihito , Maeno Shintaro , Tanizawa Yasuhiro , Kneifel Wolfgang , Arita Masanori , Dicks Leon , Salminen Seppo
Published: July 2018

Fructophilic lactic acid bacteria (FLAB) are a recently discovered group, consisting of a few
Fructobacillus
and
Lactobacillus
species. Because of their unique characteristics, including poor growth on glucose and preference of oxygen, they are regarded as “unconventional” lactic acid bacteria (LAB).
Outbreak of Glomerulonephritis Caused by Streptococcus zooepidemicus SzPHV5 Type in Monte Santo de Minas, Minas Gerais, Brazil
Authors: Torres Rosângela S. L. A. , Santos Talita Z. , Bernardes Andre F. L. , Soares Patricia A. , Soares Ana C. C. , Dias Ricardo S.
Published: July 2018

Streptococcus zooepidemicusis an emerging and opportunistic zoonotic pathogen which plays an important role in the development of severe and life-threatening diseases and is potentially capable of triggering large glomerulonephritis outbreaks. Between December 2012 and February 2013, 175 cases of glomerulonephritis were confirmed in the town of Monte Santo de Minas, MG, Brazil.
Kinesin-1 Proteins KIF5A, -5B, and -5C Promote Anterograde Transport of Herpes Simplex Virus Enveloped Virions in Axons
Authors: DuRaine Grayson , Wisner Todd W. , Howard Paul , Johnson David C.
Published: July 2018

Herpes simplex virus (HSV) and other alphaherpesviruses, such as varicella-zoster virus, depend upon the capacity to navigate in neuronal axons. To do this, virus particles tether onto dyneins and kinesins that motor along microtubules from axon tips to neuronal cell bodies (retrograde) or from cell bodies to axon tips (anterograde). Following reactivation from latency, alphaherpesviruses absolutely depend upon anterograde transport of virus particles in axons in order to reinfect peripheral tissues and spread to other hosts. Which of the many axonal kinesins transport HSV in axons is not clear. We characterized fluorescent cellular cargo molecules and kinesins to provide evidence that HSV enveloped particles are ferried by kinesin-1 proteins KIF5A, -5B, and -5C and their light chains, KLC1 and KLC2, in axons. Moreover, we obtained evidence that kinesin-1 proteins are functionally important in anterograde transport of HSV virions by silencing these proteins.
Drivers of Microbiome Biodiversity: A Review of General Rules, Feces, and Ignorance
Authors: Reese Aspen T. , Dunn Robert R.
Published: July 2018

The alpha diversity of ecologic communities is affected by many biotic and abiotic drivers and, in turn, affects ecosystem functioning. Yet, patterns of alpha diversity in host-associated microbial communities (microbiomes) are poorly studied and the appropriateness of general theory is untested.
Reconstruction of a Global Transcriptional Regulatory Network for Control of Lipid Metabolism in Yeast by Using Chromatin Immunoprecipitation with Lambda Exonuclease Digestion
Authors: Bergenholm David , Liu Guodong , Holland Petter , Nielsen Jens
Published: July 2018

Transcription factors play a crucial role in the regulation of gene expression and adaptation to different environments. To better understand the underlying roles of these adaptations, we performed experiments that give us high-resolution binding of transcription factors to their targets. We investigated five transcription factors involved in lipid metabolism in yeast, and we discovered multiple novel targets and condition-specific responses that allow us to draw a better regulatory map of the lipid metabolism.
Karst hydrogeology of Tuckaleechee Cove and the western Great Smoky Mountains, Tennessee and North Carolina
Authors: Miller Benjamin V. , Bradley Michael W. , Brown Teresa L.
Published: July 2018

The geology of Great Smoky Mountains National Park (GRSM) in Tennessee and North Carolina is dominated by siliciclastics and metamorphic strata. However, in the western portion of GRSM, a series of carbonate fensters (windows) expose the Lower Ordovician–age section of the Knox Group, a series of dolomite and limestone units that are partially marbleized as a result of contact metamorphism from the Great Smoky fault. The fensters create opportunities for allogenic recharge to occur at points along the contact of the surrounding insoluble strata with the underlying soluble carbonates. The combination of chemically aggressive surface recharge and vertical relief has resulted in the formation of deep caves, many of which have active streams and water resources. Though the karst is limited in extent and the number of caves is fairly small, the significance of the resources is substantial, with several of the caves in the area over 150 m in depth and at least two being major bat hibernacula. In 2017, the U.S. Geological Survey (USGS) began a study to better understand the hydrologic behavior of these karst systems through hydrologic and geochemical monitoring, groundwater tracing using fluorescent dyes, and seepage runs. Stage and water-quality instrumentation was installed in two caves in GRSM, the main stream of Bull Cave, and in a sump pool in Whiteoak Blowhole, at 173 m and 70 m below land surface, respectively. Following setup of the cave sites, dye injections were conducted to determine discharge points for four of the deep cave systems on Rich Mountain and Turkeypen ridge. Results show water in these systems has an extremely rapid travel time, with tracers detected from caves to springs in less than 24 h for each of the systems. This field guide describes the complex geology, regional hydrogeology, and unique landscape characterized by high-gradient subterranean streams, carbonate fensters, and deep caves of the GRSM karst.
Trends in outpatient antibiotic use and prescribing practice among US older adults, 2011-15: observational study
Authors: Olesen Scott W , Barnett Michael L , MacFadden Derek R , Lipsitch Marc , Grad Yonatan H
Published: July 2018

Objective

To identify temporal trends in outpatient antibiotic use and antibiotic prescribing practice among older adults in a high income country.

Design

Observational study using United States Medicare administrative claims in 2011-15.

Setting

Medicare, a US national healthcare program for which 98% of older adults are eligible.

Participants

4.5 million fee-for-service Medicare beneficiaries aged 65 years old and older.

Main outcome measurements

Overall rates of antibiotic prescription claims, rates of potentially appropriate and inappropriate prescribing, rates for each of the most frequently prescribed antibiotics, and rates of antibiotic claims associated with specific diagnoses. Trends in antibiotic use were estimated by multivariable regression adjusting for beneficiaries’ demographic and clinical covariates.

Results

The number of antibiotic claims fell from 1364.7 to 1309.3 claims per 1000 beneficiaries per year in 2011-14 (adjusted reduction of 2.1% (95% confidence interval 2.0% to 2.2%)), but then rose to 1364.3 claims per 1000 beneficiaries per year in 2015 (adjusted reduction of 0.20% over 2011-15 (0.09% to 0.30%)). Potentially inappropriate antibiotic claims fell from 552.7 to 522.1 per 1000 beneficiaries over 2011-14, an adjusted reduction of 3.9% (3.7% to 4.1%). Individual antibiotics had heterogeneous changes in use. For example, azithromycin claims per beneficiary decreased by 18.5% (18.2% to 18.8%) while levofloxacin claims increased by 27.7% (27.2% to 28.3%). Azithromycin use associated with each of the potentially appropriate and inappropriate respiratory diagnoses decreased, while levofloxacin use associated with each of those diagnoses increased.

Conclusion

Among US Medicare beneficiaries, overall antibiotic use and potentially inappropriate use in 2011-15 remained steady or fell modestly, but individual drugs had divergent changes in use. Trends in drug use across indications were stronger than trends in use for individual indications, suggesting that guidelines and concerns about antibiotic resistance were not major drivers of change in antibiotic use.
Nutrition Questionnaires plus (NQplus) study, a prospective study on dietary determinants and cardiometabolic health in Dutch adults
Authors: Brouwer-Brolsma Elske Maria , van Lee Linde , Streppel Martinette T , Sluik Diewertje , van de Wiel Anne M , de Vries Jeanne H M , Geelen Anouk , Feskens Edith J M
Published: July 2018

Purpose

During the past decades, the number of people with cardiometabolic conditions substantially increased. To identify dietary factors that may be responsible for this increase in cardiometabolic conditions, the Nutrition Questionnaires plus (NQplus) study was initiated. The aim of this article is to provide an overview of the study design and baseline characteristics of the NQplus population.

Participants

The NQplus study is a prospective cohort study among 2048 Dutch men (52%) and women (48%) aged 20–70 years.

Findings to date

At baseline, we assessed habitual dietary intake, conducted physical examinations (measuring, eg, anthropometrics, body composition, blood pressure, pulse wave velocity, advanced glycation end product accumulation, cognitive performance), collected blood and 24-hour urine and administered a variety of validated demographic, health and lifestyle questionnaires. Participants had a mean BMI of 26.0±4.2 kg/m2, were mostly highly educated (63%), married or having a registered partnership (72%) and having a paid job (72%). Estimated daily energy and macronutrient intakes (mean±SD) were 8581±2531 kJ, 15±2energy (en%) of protein, 43±6 en% of carbohydrates, 36±5 en% of fat and 11±13 g of alcohol. Mean systolic blood pressure was 126±15 mm Hg, total cholesterol 5.3±1.1 mmol/L and haemoglobin A1c 36±5 mmol/mol. A total of 24% of the participants reported to be diagnosed with hypertension, 18% with hypercholesterolaemia and 4% with diabetes mellitus. All measurements were repeated after 1 and 2 years of follow-up.

Future plans

We endeavour to continue measurements on the long-term. Moreover, dietary assessment methods used in the NQplus study will be extensively validated, that is, Food Frequency Questionnaires, 24-hour recalls and urinary and blood biomarkers of exposure. As such, the NQplus study will provide a unique opportunity to study many cross-sectional and longitudinal associations between diet and cardiometabolic health outcomes using the best dietary assessment methods available so far.