bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of Minocycline in Naturally Occurring Nonacute Ehrlichia canis Infection in Dogs
Authors: Jenkins S. , Ketzis J.K. , Dundas J. , Scorpio D.
Published: December 2017

Background

Minocycline has been used in the treatment of Ehrlichia canis infection in dogs as an alternative to doxycycline, the recommended treatment. However, efficacy of this alternative therapy is unknown.

Objective

To assess the efficacy of minocycline in the treatment of natural occurring E. canis infection in dogs.

Animals

Ten privately owned dogs of mixed breed positive for E. canis by blood PCR.

Methods

Prospective, randomized clinical study. Dogs positive for E. canis by PCR were housed in a kennel environment and randomly allocated to receive doxycycline 10 mg/kg bodyweight PO once daily (“gold standard” control group) or minocycline (extralabel) 10 mg/kg bodyweight PO twice daily (treatment test group) for 28 days. Blood, analyzed by PCR to determine the presence or absence of E. canisDNA, was collected weekly during treatment starting on the first day of treatment and including through day 35, 7 days after the last treatment.

Results

In both groups, one dog tested negative after 7 days of treatment. For the doxycycline group, the latest time to a negative PCR test was after 3 weeks of treatment. For the minocycline group, the latest time was on day 28 of treatment. All dogs tested negative 7 days after the end of treatment.

Conclusion and Clinical Importance

Minocycline can be an effective alternative to doxycycline for clearing E. canis from the blood in nonacute infections.
A Remote Assay for Measuring Canine Platelet Activation and the Inhibitory Effects of Antiplatelet Agents
Authors: Dunning M. , May J. , Adamany J. , Heptinstall S. , Fox S.
Published: December 2017

Background

Antiplatelet medications are increasingly used in dogs. Remote analysis of platelet activity is challenging, limiting assessment of antiplatelet drug efficacy.

Hypothesis/Objectives

To evaluate a method used in humans for stimulation and remote analysis of canine platelet activity.

Animals

Forty‐five dogs of various ages without a coagulopathy or thrombocytopenia. Six were receiving antiplatelet medication.

Methods

Prospective observational study. Platelets were stimulated with combinations of arachidonic acid (AA) and epinephrine (Epi) or adenosine diphosphate (ADP) and the thromboxane A2‐mimetic U46619 (U4).PAMFix was added to the blood samples to facilitate delayed analysis of platelet activity. Activity was assessed by flow cytometric measurement of surface P‐selectin (CD62P) expression.

Results

Canine platelets could be stimulated with bothAA/Epi andADP/U4. The levels of P‐selectin were significantly greater than paired, unstimulated samples (P < 0.001). Inhibition of P‐selectin expression occurred after this stimulation by adding antiplatelet drugs in vitro. The efficacy of antiplatelet drugs in samples from treated dogs was also measurable ex vivo using this method. Delayed analysis of platelet activity at time points up to 22 days demonstrated excellent correlation between respective mf values at each time point (r2 = 0.92,P < 0.0001).

Conclusions and Clinical Importance

This study evaluated a new method to remotely assess canine platelet activity. It shows thatPAMFix can be used for this purpose. This provides opportunities to interrogate the inhibitory action of antiplatelet drugs in clinical settings.
Accurate Method for Loss Parameter Extraction of Solar Panels
Authors: Bencherif M. , Brahmi B. N.
Published: December 2017

This work describes a new simple and effective method to extract the loss parameters of solar panels (solar cells) and able to accurately represent their electrical behavior. This approach allows the extraction of the parameters of the single diode model using only the information provided by the manufacturer's data sheet. The proposed method presents a computational procedure of low complexity, which makes it possible to estimate the five parameters of any photovoltaic generator. Using the complete equation of the single diode model, the number of parameters to be calculated is reduced only to two parameters by an equation exclusively connecting the series resistance and the diode current. Suitable validations on important case studies are presented; an experimental data from multicrystalline MSX120 and thin film NA-F135 solar panels were used to test the single diode model with the extracted parameters. The experimental data are first collected at the same temperature at two different irradiances levels and at low irradiance level at a fixed temperature for MSX120. In the second stage, variations in temperature are considered at different irradiance level for NA-F135. The extraction results show that the I–V curves accurately fit the entire range of the experimental data. In addition, the results of the proposed procedure are compared to the most recent proposed techniques in literature. Furthermore, the results obtained show a highly accurate; in particular, at maximum power point (MPP), the error is always less than 0.005%, which is quite far of the authorized error of 1%.
A Novel Intermittent Gas Lifting and Monitoring System Toward Liquid Unloading for Deviated Wells in Mature Gas Field
Authors: Tong Zheng , Zhao Guangmin , Wei Songbo
Published: December 2017

For liquid-loading gas wells, effective deliquification operation is needed but current liquid-lifting technology is not able to meet the requirements of high efficiency as well as low cost especially in large-deviated wells. This paper proposes a hybrid deliquification technology combining plunger lift, chemical foamer injection, and down-hole monitoring to unload liquid in deviated gas wells. The system comprised multipart plunger body, deployment-retrieving integrating assembly (DRIA) and operation canisters. By means of flexible plunger body, the system performs deliquification normally in deviated wellbore. The operation canisters are carried with plunger body through tubing onto the bottom of deviated section to operate in terms of four modes: long-term down-hole monitoring, foamer injection, mobile data acquisition, and wireless data exchange with the wellhead. The key components of DRIA and injection valve are made of improved disintegrating alloy with the rating temperature of 100 °C, compressive strength of 370 MPa, and disintegrating rate of 170.9 mg/(cm2 h) characterized by lab test. Field trials were successfully performed in two liquid-loading tight gas wells, and the maximal deviated angle of the wells was 68 deg. It indicates that the new technology is a cost-effective way contributing to automatic production and management of mature gas wells in the remote area instead of traditional rigid plunger and wire-line logging.
Hydro-Mechanical Constant-Speed Motion Control Using Shear Thickening Fluid
Authors: Sleiman Mohamad , Hassoun Karim , Liermann Matthias
Published: December 2017

This paper proposes a novel approach to control the velocity of a piston using dilatant fluid. Commonly, a pressure compensated flow control valve is used for this purpose. It produces excellent results but is mechanically complex. A setup is proposed that makes use of the unique properties of dilatant (i.e. shear thickening) non-Newtonian fluids. A simple tube section filled with dilatant material can be used to achieve very low sensitivity of flow rate vs. pressure difference. A numerical study shows how the power law which relates the fluid shear rate to its viscosity results in this low sensitivity of flow to pressure difference. An experimental setup was build to validate the findings using a cheap and commercially available shear thickening fluid. It was found that the dilatant material used does not have a highly pronounced dilatant property and therefore the sensitivity of flow vs. pressure difference was not as low as desired. Nevertheless, the results support the practical applicability of this novel type of velocity control.
Numerical Modeling of Gaseous Cavitation in CFD of Hydraulic Oil Flow Based on Dynamic Stimulation
Authors: Matsuura Yudai , Kumagai Kento , Iga Yuka
Published: December 2017

In this paper, the cavitation phenomenon in hydraulic oil is investigated, and a new gaseous cavitation model based on the dynamic stimulation is examined. Before modeling, to confirm the characteristics of cavitation occurrence in hydraulic oil flow, the comparison of our previous experiment with the pressure distribution by CFD has been conducted. It is clarified that the region where the cavitation bubbles appear do not agree with the low pressure region, which indicates they are not in the case of vaporous cavitation. This comparison indicates that the gaseous cavitation has been occurred predominantly in the previous experiment. In modeling, the dynamic stimulation of unsteady flow field is assumed to play a major role in the liberation of dissolved air. The dynamic stimulation is transferred into the dimension of pressure and applied to the threshold pressure of liberation. Several models considering dynamic stimulation are proposed and comparison of the effect of those models has conducted to estimate the most appropriate modeling.
Comparison of Methods for Measuring Pump Flow Ripple and Impedance
Authors: Bramley Chris , Johnston Nigel
Published: December 2017

Positive displacement pumps produce flow and pressure ripple due to their pumping mechanism. Two ISO standard methods for measuring pump ripple were compared in terms of accuracy, sensitivity, reliability and practical difficulty. These were the “secondary source” (SS) method (ISO 10767-1: 1996) and the “2 pressures / 2 systems” (2P2S) method (ISO 10767-1: 2015). The 2P2S method has recently replaced the secondary source as the ISO standard for precision testing although the UK has retained the SS method for its BS ISO standard.

The methods produced similar source impedance and flow ripple results. The SS method enabled a wider range of operating conditions to be tested due to the more flexible circuit arrangement but the impedance results were affected by interference between the test pump and secondary source at the pumping harmonic frequencies. It was found that the simpler 2P2S circuit allowed measurements to be taken faster, but measurements were only valid at the pumping harmonic frequencies. Both methods were found to produce repeatable results provided there was no trapped air in the circuit.

Overall, the SS method was considered the stronger technique in terms of repeatability, accuracy, sensitivity and practicality, but it had a more complex data processing and experimental set up. It had more flexibility, which enabled the pump to be tested over the widest range of operating conditions, and the fluid borne noise characteristics of the test pump could be evaluated completely. The authors consider that the 2P2S method could be improved by the inclusion of a third transducer, and that it would be beneficial to retain the SS method as an alternative Standard.
Cavitation and Turbulence Modelling for Valve Flows: An Application to a Pilot Stage of a Servo Valve
Authors: Longhitano Marco , Chighine Marco , Murrenhoff Hubertus
Published: December 2017

Standard Computational Fluid Dynamic (CFD) techniques are widely used in the design of hydraulic valves for optimising the valve performance and reducing the production effort. They calculate the turbulent flow and predict cavitation. Unfortunately, the currently used models are often inadequate and out of date to catch the complexity of these phenomena such as the transient interaction between cavitation and turbulence. Advanced computational methods have been developed and applied to other engineering branches. Despite this fact, they face many difficulties to be employed in hydraulics. In this paper, a first step is taken towards the usage of these cutting edge CFD methods for hydraulic valves. At first, the different challenges for a CFD code to simulate valve flows are highlighted. A novel computational approach is then presented. It combines a Large Eddy Simulation (LES) model for the turbulence modelling as well as a Full Cavitation Model (FCM). The LES technique explicitly resolves the large turbulence scales while the smaller ones are modelled. The FCM not only predicts vapour but also gas cavitation, which plays a vital role in hydraulic fluids. This method is tested to simulate the flow in a pilot stage of a jet-pipe servo-valve. The test case is presented and the different boundary conditions used for the simulations are given. The results of the simulation are compared with experimental results showing a good agreement. A comparison between the LES model and the standard two-equation turbulence model shows the advantages of the LES approach. Finally, the transient features of the flow are highlighted in terms of velocity oscillation.
Research on Sealing Performance in High Pressure Oil-Free Miniature Air Compressor
Authors: Deng Yipan , Liu Yinshui , Li Fan , Tian Pengyun , Miao Na
Published: December 2017

High pressure oil-free miniature air compressor has an irreplaceable role in some high demand areas such as cooling, scuba diving and pneumatic catapult due to its remarkable advantages such as compacted size, lightened weight and clean output gas. As the important sealing component in the high pressure oil-free miniature air compressor, piston rings hold the properties such as tiny diameter (less than 10mm), high sealing pressure (up to 410 bar) and high surrounding temperature (up to 500K), which make them distinctive from conventional piston rings. A mathematical model was established to simulate the pressure distribution of the compressor chamber, as well as the gap between the sealing rings. Sensitive parameters were considered to investigate their effects on the sealing performance such as the number and the cut size of the piston rings, the suction and discharge pressure and the rotary speed. The mathematical model was verified by comparing to published experimental research work. These work help to reveal the severe non-uniformity of the pressure distribution of different chambers, which were suggested be the primary cause of the premature failure of the sealing rings, thus improving the sealing performance and the service life of the air compressor.
A Miniature On/Off Valve Concept for High Performance Water Hydraulics
Authors: Paloniitty Miika , Linjama Matti
Published: December 2017

Digital hydraulic control valve technology has shown its strengths in providing reliable, leak-tight and high performance valve control regardless of the pressure medium used, oil or water. This is enabled by the intelligent use of robust on/off seat valves. However, the availability of these valves for water hydraulics is limited, especially that of compact valves, which are needed for digital valve systems. Thus, with the aim to create a compact digital water hydraulic valve system, this paper presents the development process of a water hydraulic miniature valve. The starting point for the development is a previously developed miniature valve for oil hydraulics. Experimental results with the new prototype show that good performance can be achieved for the miniature valve even with using stainless steel materials. This enables high-performance digital water hydraulic control.
Automated Feed-Forward Learning for Pressure-Compensated Mobile Hydraulic Valves With Significant Dead-Zone
Authors: Nurmi Jarmo , Mattila Jouni
Published: December 2017

Hydraulic manipulators on mobile machines, whose hydraulic actuators are usually controlled by mobile hydraulic valves, are being considered for robotic closed-loop control. A feed-forward-based strategy combining position and velocity feedback has been found to be an effective method for the motion control of pressure-compensated mobile hydraulic valves that have a significant dead zone. The feed-forward can be manually identified. However, manually identifying the feed-forward models for each valve-actuator pair is often very time-consuming and error-prone. For this practical reason, we propose an automated feed-forward learning method based on velocity and position feedback. We present experimental results for a heavy-duty hydraulic manipulator on a forest forwarder to demonstrate the effectiveness of the proposed method. These results motivate the automated identification of velocity feed-forward models for motion control of heavy-duty hydraulic manipulators controlled by pressure-compensated mobile hydraulic valves that have a significant input dead zone.
A Robust Control Concept for Hydraulic Drives Based on Second Order Sliding Mode Disturbance Compensation
Authors: Schmidt Lasse , Andersen Torben O. , Johansen Per , Pedersen Henrik C.
Published: December 2017

The application of sliding mode algorithms for control of hydraulic drives has gained increasing interest in recent years due to algorithm simplicity, low number of parameters and possible excellent control performance. Both application of first- and higher order sliding mode control algorithms in hydraulic drive controls have been presented in various literature, demonstrating the possible successful application of these. However, a major drawback is the presence of e.g. valve dynamics which often necessitates the usage of continuous approximations of discontinuities in order to avoid control chattering, which on the other hand compromises the robustness properties. This may also be the case when discontinuities are only present in the control derivative. This fact suggests that sliding mode algorithms may be more appropriate for assisting the control, i.e. for state observation, disturbance observer based control etc., and several examples of such approaches have been presented in literature. The latter case appear especially interesting as a sliding mode actually takes place, but only the low-pass filtered sliding mode algorithm output is used in the actual control input. However, the successful implementation relies heavily on the low-pass filter design where the drive dynamics, sample rate etc. play a significant role. In this paper the utilization of the super twisting algorithm for disturbance compensation is considered. The fact that the discontinuity here is nested in an integral causes less restrictions on the used low-pass filter, enabling the possibility for a wide range of usage when the sampling frequency is in the range of industrial grade control hardware. The proposed control structure is designed and considered in relation to a valve driven hydraulic winch drive, and results demonstrate that excellent and high precision control may be achieved in the presence of large and highly varying external loads.
A Combined 0D-3D Numerical Approach for the Performance Prediction of Vehicles’ Heat Exchangers Under Actual Operating Conditions
Authors: Montorsi Luca , Martelli Massimo , Gessi Silvia , Milani Massimo
Published: December 2017

The paper focuses on the development of a predictive numerical tool for the performance assessment of air-cooled cross-flow heat exchangers for vehicle application. First, a CFD approach for the simulation of vehicles’ radiators under actual operating conditions is proposed. The numerical analysis accounts both for the thermo-fluid dynamics behavior of each section of the heat exchanger and for the flow characteristics of the adopted fan. The full-scale geometry of the fan is included in the simulation as well as the casing and the real rotational speed. The CFD results are used to correlate the flow distribution across the different radiator’s sections and the actual working conditions of both the heat exchanger and the fan operation.

Following this methodology, a generic radiator was divided in two different sub-domain types (internal/boundary), and for each one the Wall Heat Transfer Coefficient and the pressure drop 2D maps are determined on the basis of preliminary CFD simulations as functions of fluid velocity and temperature. These elements became the elementary blocks to be used by a custom-made algorithm to characterize exchangers of any size. The algorithm was extended to develop a fully featured PC software to calculate the performance of multiple sections exchangers.
Modeling and Simulation of a Hydraulic Drill for Control System Design Purposes
Authors: Peltokangas Suvi , Launis Sirpa , Saarela Markus , Mattila Jouni
Published: December 2017

In rock excavation processes, hydraulic rotary-percussive drilling is used for drilling and blasting in both surface and underground drilling operations. A hydraulic percussive drilling system is composed of percussion, rotation, feed, and flushing functions. In this paper, we detail the interaction of feed and rotation functions using a rock model. The feed actuator is a cylinder drive and a hydraulic motor actuator rotates the drill bit. The feed is force controlled and rotation is torque controlled by a feed reduction valve acting on the pressure compensator of the mobile hydraulic proportional directional control valve. In addition, in this work an individual load sensing variable displacement pump is used for both hydraulic functions. A suitable rock model is developed and verified against a measurement set. The inputs of the rock model are percussion drill flow rate, percussion pressure, feed force, and rotation torque, and the outputs are drill bit penetration rate and rotational speed. The modeling work is carried out to enable intelligent rock drilling control system development for changing rock conditions. The simulation results obtained verify that the simple rock model emulates various rock characteristics ranging from extremely hard rock like granite to softer minerals and that the changes in drilling parameters were as expected.
Wave-to-Wire Simulation of Hydraulic Wave Energy Converter
Authors: Zha Rongyu , Hillis Andrew , Darling Jos , Plummer Andrew
Published: December 2017

This paper introduces the simulation of a wave-to-wire (W2W) wave energy converter (WEC) design that includes the complete system from the original wave capture device to the final generated electricity supplied to the grid. Instead of designing the sub-systems separately, this holistic approach allows the optimization of the WEC performance. The Energy Capture Device (ECD), the absorption stage, is based on heaving theory, namely a point absorber. The Power Take-Off (PTO) system, the transmission stage, is based upon a hydrostatic transmission. Lastly the WIRE side, the generation stage, is achieved by connecting a three-phase round-rotor synchronous generator driven by the hydraulic motor from the PTO system. The control strategy primarily aims to meet the criteria of the grid while extracting as much energy from the waves as possible.
On-Line Path Planning With Collision Avoidance for Coordinate-Controlled Robotic Manipulators
Authors: Kivelä Tuomo , Mattila Jouni , Puura Jussi , Launis Sirpa
Published: December 2017

This paper presents a generic method for generating joint trajectories for robotic manipulators with collision avoidance capability. The coordinate motion control system of the heavy-duty hydraulic manipulator resolves joint references so that a goal pose can be reached in real-time without any collisions. The control system checks whether any part of the manipulator is at risk of colliding with itself, with other manipulators, or with environmental obstacles. If there is a risk of collision, then the collision server searches the points where the collision is about to occur and calculates the shortest distance between the colliding objects. The collision server retains static and dynamic point clouds, and it uses point cloud data to calculate the shortest distance between the colliding objects. The point clouds on the server are kept up to date with the manipulators’ joint sensors and an external surveillance system. During coordinated motion control, the joint trajectories of the hydraulic manipulator are modified so that collisions can be avoided, while at the same time, the trajectory of the end-effector maintains its initial trajectory if possible. Results are given for a seven degrees of freedom redundant hydraulic manipulator to demonstrate the capability of this collision avoidance control system.
Investigation of Squeeze Film Damping and Associated Loads
Authors: Johansen Per , Bender Niels C. , Hansen Anders H. , Schmidt Lasse
Published: December 2017

Digital hydraulics have attracted attention towards fast switching valves and the increased focus on reliable fluid power entail that the lifetime of such valves is of great concern. An inherent feature of most valves for digital hydraulics is that of a mechanical end stop. Consequently, the squeeze film damping associated with end stops of switching valves is an interesting topic. This damping effect is perceived as beneficial for high lifetime and low impact sound, as the consequence of lowering the impact velocity at the mechanical end stops. In this paper the squeeze film damping effect is reviewed with a focus on maximum surface stresses. Using the Barus relation for viscosity-pressure dependency and different film geometries, the classical lubrication theory is applied together with the equation of motion, to obtain the gap height motion equation, both for the iso-viscous and piezo-viscous case. In consequence, this enable insights concerning the influence of piezo-viscosity on this damping effect. These models are used to investigate the loads, which the approaching surfaces experiences. Based on Hertzian theory, comparisons of impact loads and the dynamic squeeze loading are performed, whereby the relation between design parameters and the relative severity of these occurrences are analyzed.
Optimized Control for an Independent Metering Valve With Integrated Diagnostic Features
Authors: Campanini Federico , Bianchi Riccardo , Vacca Andrea , Casoli Paolo
Published: December 2017

This paper presents an optimized control for independent metering hydraulic systems that integrates machine diagnostic features. The machine under study is a hydraulic crane for truck applications equipped with a post compensated Load Sensing Pressure Compensated (LSPC) independent metering valve. Control challenges of such hydraulic system pertain to the determination of the opening of the meter-out section under overrunning load conditions. In this work, the inlet actuator pressure was used as feedback for a PI control architecture. The gains of the PI regulator were defined through an Extremum Seeking (ES) optimization algorithm, which minimizes cost functions representative of energy consumption and occurrence of cavitation, to achieve optimal performance in different operating conditions. The control was tested on a simulation model of the reference machine developed in AMESim and validated against experimental results.

The paper shows that the same cost functions used to define the controller parameters can be used as additional inputs, along with conventional sensors, to monitor the health status of the machine.
Experimental Study on Active Pneumatic Damping of Pulsatile Flow Delivered From Peristaltic Pump
Authors: Asmar Elias , Bejjani Gilles , Chamoun Rami , Hachem Joe , Oweis Ghanem , Liermann Matthias
Published: December 2017

Hemodynamic flow loops are widely used for research on causes and cures of cardiovascular diseases. They replicate physiological blood flow pulsatility in vitro. Many different pump types exist for such flow loops. The variety of the flow loop types shows the lack of one concept that satisfies all requirements, which are ease of handling and sterilization, flexible and accurate realization of various profiles, low shear rate exerted on fluid, low amount of circulating fluid. This paper experimentally proves the concept of a new type of pulse damping/pulse generating device that can be used for flow loops that are operated with a peristaltic pump. The pulse generating device fulfills the double function of damping the undesired pulsatility of the peristaltic pump and injecting a desired pulsatility that replicates the flow profile delivered by the heart. The injection of the desired pulsatility is achieved by modulation of air pressure in a damping device. The experimental results show that it is possible to achieve the dual function in one device. An electromagnetic flow sensor provides the feedback for the air pressure control and a high-response flow control valve controls the pressure in the pulse damper/generator. The response time and accuracy of the sensor proved to be critical for achieving the objective. With the limitations of the relatively cheap components used for this functional prototype, the mean error in the flow rate signal could be kept below 10% for a simulated adult pulse rate of 60bpm.
Theoretical and Experimental Study of Whirl and Stability Phenomena in Internal Gear Motor/Pump
Authors: Hoa Pham , Müller Lutz , Weber Jürgen
Published: December 2017

The stability of the internal gear motor/pump is mostly determined by the stability of the ring gear. In order to get insight into the stability of the motor/pump, the Sommerfeld theory and the micro-motion of the ring gear are used to define stable and unstable operating areas of the internal gear motor/pump. A test rig was designed and built. Experimental investigations were performed to validate the theoretical analytical results. The internal gear motor/pump worked in different regimes. The minimum film thickness, trajectories of the ring gear, as well as the whirl motion phenomena have been studied experimentally. Moreover, it is interesting that both forward and backward whirling motion of the ring gear have been observed experimentally. Based on the minimum film thickness, the trajectories, forward and backward whirling motion of the ring gear allow determining the stability and instability of the internal gear motor/pump corresponding to the rotating speed and the working pressure.
Investigation of a Real-Time Pressure Based Valve Timing Correction Algorithm
Authors: Breidi Farid , Garrity Jordan , Lumkes John
Published: December 2017

Digital hydraulics is an emerging field in fluid power, complementing conventional hydraulic and potentially improving efficiency and dynamic performance. High speed electrically controlled on/off valves are key enablers for many digital hydraulic systems, and specifically for digital pump/motors. This work investigates a 4-quadrant 3-piston digital pump/motor utilizing two electrically controlled high speed on/off valves per displacement chamber. The test unit was simulated, built, and experimentally tested. Simulation and experimental results showed the importance of valve response times on the overall performance and efficiency of the digital pump/motor, where a small error in the delay in the valve opening or closing could lead to significant energy losses.

To minimize the impact of valve variability, a real-time valve correction algorithm was developed to account for the error in valve timing. The algorithm uses the pressure readings at the low and high pressure ports to detect the time at which the pressure ripple occurred and then obtain the delay in the valve timing. It calculates the turn-on and turn-off valve delay times in all displacement chambers in a three-piston pump with two valves per chamber, detecting a total of 12 valve delay times. The code was tested for sequential flow diverting and sequential flow limiting operating modes at a wide range of displacement (25% to 100%) with pressures ranging from 25 bar to 105 bar and shaft speeds up to 700 rpm (limited by the valves speed). It was also tested for flow diverting mode and gave good results for displacements between 70% and 100%. The error in the calculated delay times was below 5% in all of the tested conditions, providing major improvements to the digital pump system, and to digital hydraulics in general.
Modeling and Design of a Hydraulic Hybrid Powertrain for Passenger Vehicle
Authors: Zhang Haoxiang , Wang Feng , Stelson Kim A.
Published: December 2017

A hydraulic hybrid powertrain for passenger vehicle is studied in this paper. The hydraulic hybrid powertrain consists of a hydro-mechanical transmission and a hydraulic accumulator. The key component of this hydro-mechanical transmission is a pressure-controlled hydraulic transmission. It combines pumping and motoring function in one unit and is potentially more competitive in terms of both energy efficiency and cost effectiveness than a conventional hydrostatic transmission. By feeding the output flow of the pressure-controlled hydraulic transmission to a variable displacement motor coupled to the transmission output shaft, a more compact and simpler hydro-mechanical transmission is constituted. In this paper the systematic approach of applying the hydraulic hybrid powertrain to a passenger vehicle is studied. A dynamic simulation model is developed in Simulink and the U.S. EPA’s urban cycle is used as the test driving cycle. A rule-based energy management strategy (EMS) for the hydraulic hybrid powertrain has also been developed. The system parameter design, controller design and the energy management strategy are evaluated through simulation.
Optical constants of SiO2 from 196 to 1688 nm (0.735–6.33 eV) from 20, 40, and 60 nm films of reactively sputtered SiO2 on Eagle XG® glass by spectroscopic ellipsometry
Authors: Johnson Brian I. , Cushman Cody V. , Rowley Joseph , Lunt Barry M. , Smith Nicholas J. , Martin Andrew , Linford Matthew R.
Published: December 2017

Three thicknesses of reactively sputtered SiO2, nominally 20, 40, and 60 nm, deposited on Corning Eagle XG® (EXG), an important display glass, were analyzed by spectroscopic ellipsometry. Reflection ellipsometry data from the samples were analyzed from 196 to 1688 nm at angles of 55°–60°, inclusive, in 1° increments. These angles were chosen because they bracket the Brewster angles of both EXG glass and SiO2. The backsides of the samples were roughened by sand blasting to suppress backside reflections from the substrates. A total of nine datasets were collected from nine different samples (three for each nominal thickness of SiO2), each at six different angles of incidence (54 spectra). The optical constants for each thickness of SiO2 was determined, as well as a set of constants for all the films (the material in general) via a multisample analysis (MSA). The optical constants of the SiO2 films were modeled using two poles with transparency assumed over the entire spectral range (a Sellmeier model). A Bruggeman effective medium approximation (BEMA) roughness layer was included in the model, which assumed 50/50 volume fractions that corresponded to the modeled SiO2 optical constants and void. The fit did not substantially improve when an interface layer between the Eagle XG® and the sputtered film was included, so it was omitted. Three sets of previously reported optical constants for the substrate over two wavelength ranges were considered in the modeling. The thin SiO2 films analyzed herein have very similar optical properties to those of their EXG substrate—this is a challenging analytical problem involving a transparent film on a transparent substrate. Accordingly, analysis of multiple samples, an MSA that included multiple film thicknesses analyzed at multiple angles, and an exploration of multiple modeling approaches helped ensure that the optical constants reported herein are accurate and the modeling robust. In particular, these measures helped avoid correlation between the optical constants, the layer thicknesses, and the thicknesses of the BEMA layers. Atomic force microscopy roughness measurements were made on the SiO2 films and compared to the roughness values obtained by spectroscopic ellipsometry. In summary, the authors provide here the optical constants and some accompanying physical characterization of sputtered 20–60 nm SiO2 films from 196 to 1688 nm.
Masking release by combined spatial and masker-fluctuation effects in the open sound field
Authors: Middlebrooks John C.
Published: December 2017

In a complex auditory scene, signals of interest can be distinguished from masking sounds by differences in source location [spatial release from masking (SRM)] and by differences between masker-alone and masker-plus-signal envelopes. This study investigated interactions between those factors in release of masking of 700-Hz tones in an open sound field. Signal and masker sources were colocated in front of the listener, or the signal source was shifted 90° to the side. In Experiment 1, the masker contained a 25-Hz-wide on-signal band plus flanking bands having envelopes that were either mutually uncorrelated or were comodulated. Comodulation masking release (CMR) was largely independent of signal location at a higher masker sound level, but at a lower level CMR was reduced for the lateral signal location. In Experiment 2, a brief signal was positioned at the envelope maximum (peak) or minimum (dip) of a 50-Hz-wide on-signal masker. Masking was released in dip more than in peak conditions only for the 90° signal. Overall, open-field SRM was greater in magnitude than binaural masking release reported in comparable closed-field studies, and envelope-related release was somewhat weaker. Mutual enhancement of masking release by spatial and envelope-related effects tended to increase with increasing masker level.
Phase-shift expansions for approximate radiation forces on solid spheres in inviscid-acoustic standing waves
Authors: Marston Philip L.
Published: December 2017

Previously acoustic radiation forces on spheres have been expressed using scattering phase shifts associated with the corresponding traveling wave scattering situation. That approach is applied here to spheres in inviscid standing waves that are solid, fixed-rigid, or movable-rigid of finite density. Low frequency truncated expansions of the phase shifts result in expressions for radiation forces that have simple forms. The expansion expresses the leading finite-size correction to the common low-frequency approximation associated with Rayleigh scattering in which the radiation force is proportional to the solid sphere's volume.
Host-Pathogen-Treatment Triad: Host Factors Matter Most in Methicillin-Resistant Staphylococcus aureus Bacteremia Outcomes
Authors: Guillamet M. Cristina Vazquez , Vazquez Rodrigo , Deaton Benjamin , Shroba Jenny , Vazquez Laia , Mercier Renee-Claude
Published: December 2017

Previous studies have separately emphasized the importance of host, pathogen, and treatment characteristics in determining short-term or in-hospital mortality rates for patients with methicillin-resistant
Staphylococcus aureus
(MRSA) bloodstream infections. Less is known about the relative importance of these factors and their interactions in determining short-, medium-, and long-term mortality rates. This is an observational cohort study in which data for all patients admitted to the University of New Mexico (UNM) Health Sciences Center (HSC) between July 2002 and August 2013 with MRSA-positive blood cultures were recorded. We collected patients' demographics and treatment data, as well as data on genetic markers of the MRSA isolates. Outcomes of interest were determinants of short-term (within 30 days), medium-term (30 to 90 days), and long-term (>90 days) mortality rates. This study included 273 patients with MRSA bacteremia. Short-, medium-, and long-term mortality rates were 18.7%, 26.4%, and 48%, respectively. Thirty-day mortality rates were influenced by host variables and host-pathogen interaction characteristics. Pitt bacteremia scores, malignancy, and health care exposure contributed to 30- to 90-day mortality rates, while treatment duration of >4 weeks had a protective effect. Age remained a significant risk factor for death at >90 days, while admission leukocytosis was protective. Infection represented the most frequent cause of death for all three time frames; rates varied from 72.6% in the first 30 days and 60% for 30 to 90 days to 35.7% for >90 days (
P
= 0.003). Host characteristics affect short-, medium-, and long-term mortality rates for MRSA bloodstream infections more than do pathogen genetic markers and treatment factors.
Prospective Trial on the Use of Trough Concentration versus Area under the Curve To Determine Therapeutic Vancomycin Dosing
Authors: Neely Michael N. , Kato Lauren , Youn Gilmer , Kraler Lironn , Bayard David , van Guilder Michael , Schumitzky Alan , Yamada Walter , Jones Brenda , Minejima Emi
Published: December 2017

We hypothesized that dosing vancomycin to achieve trough concentrations of >15 mg/liter overdoses many adults compared to area under the concentration-time curve (AUC)-guided dosing. We conducted a 3-year, prospective study of vancomycin dosing, plasma concentrations, and outcomes. In year 1, nonstudy clinicians targeted trough concentrations of 10 to 20 mg/liter (infection dependent) and controlled dosing. In years 2 and 3, the study team controlled vancomycin dosing with BestDose Bayesian software to achieve a daily, steady-state AUC/MIC ratio of ≥400, with a maximum AUC value of 800 mg · h/liter, regardless of trough concentration. For Bayesian estimation of AUCs, we used trough samples in years 1 and 2 and optimally timed samples in year 3. We enrolled 252 adults who were ≥18 years old with ≥1 available vancomycin concentration. Only 19% of all trough concentrations were therapeutic versus 70% of AUCs (
P
< 0.0001). After enrollment, median trough concentrations by year were 14.4, 9.7, and 10.9 mg/liter (
P
= 0.005), with 36%, 7%, and 6% over 15 mg/liter (
P
< 0.0001). Bayesian AUC-guided dosing in years 2 and 3 was associated with fewer additional blood samples per subject (3.6, 2.0, and 2.4;
P
= 0.003), shorter therapy durations (8.2, 5.4, and 4.7 days;
P
= 0.03), and reduced nephrotoxicity (8%, 0%, and 2%;
P
= 0.01). The median inpatient stay was 20 days among nephrotoxic patients versus 6 days (
P
= 0.002). There was no difference in efficacy by year, with 42% of patients having microbiologically proven infections. Compared to trough concentration targets, AUC-guided, Bayesian estimation-assisted vancomycin dosing was associated with decreased nephrotoxicity, reduced per-patient blood sampling, and shorter length of therapy, without compromising efficacy. These benefits have the potential for substantial cost savings. (This study has been registered at ClinicalTrials.gov under registration no. NCT01932034.)
Mapping Protective Regions on a Three-Dimensional Model of the Moraxella catarrhalis Vaccine Antigen Oligopeptide Permease A
Authors: Perez Antonia C. , Johnson Antoinette , Chen Ziqiang , Wilding Gregory E. , Malkowski Michael G. , Murphy Timothy F.
Published: December 2017

A vaccine against
Moraxella catarrhalis
would reduce tremendous morbidity, mortality, and financial burden by preventing otitis media in children and exacerbations of chronic obstructive pulmonary disease (COPD) in adults. Oligopeptide permease A (OppA) is a candidate vaccine antigen that is (i) a nutritional virulence factor expressed on the bacterial cell surface during infection, (ii) widely conserved among strains, (iii) highly immunogenic, and (iv) a protective antigen based on its capacity to induce protective responses in immunized animals. In the present study, we show that the antibodies to OppA following vaccination mediate accelerated clearance in animals after pulmonary challenge. To identify regions of OppA that bind protective antibodies, truncated constructs of OppA were engineered and studied to map regions of OppA with surface-accessible epitopes that bind high-avidity antibodies following vaccination. Protective epitopes were located in the N and C termini of the protein. Immunization of mice with constructs corresponding to these regions (T5 and T8) induced protective responses. Studies of overlapping peptide libraries of constructs T5 and T8 with OppA immune serum identified two discrete regions on each construct. These potentially protective regions were mapped on a three-dimensional computational model of OppA, where regions with solvent-accessible amino acids were identified as three potentially protective epitopes. In all, these studies revealed two regions with three specific epitopes in OppA that induce potentially protective antibody responses following vaccination. Detection of antibodies to these regions could serve to guide vaccine formulation and as a diagnostic tool for monitoring development of protective responses during clinical trials.
The clinical and prognostic relevance of driver mutations in 203 Taiwanese patients with primary myelofibrosis
Authors: Kuo Ming-Chung , Lin Tung-Huei , Sun Chien-Feng , Lin Tung-Liang , Wu Jin-Hou , Wang Po-Nan , Huang Ying-Jung , Chang Hung , Huang Ting-Yu , Shih Lee-Yung
Published: December 2017

Aims

We investigated the clinical and prognostic relevance of the mutational status of driver genes with allele burden and endogenous erythroid colony (EEC) growth in 203 Taiwanese patients with primary myelofibrosis (PMF).

Methods

Pyrosequencing was used to detectJAK2V617Fmutational status and measure allele burden, whileMPL(exon 10) mutations were analysed by PCR assay and then by direct sequencing.CALRexon 9 mutations were first screened for length changes by GeneScan followed by sequencing. The allele burden of the mutatedCALRgene was measured by pyrosequencing. The EEC assay was conducted using a serum-free culture system.

Results

The frequencies of the three driver mutations and triple-negative status were similarly distributed between pre-PMF and overt PMF patients, except that pre-PMF patients had a higher incidence ofCALRtype 2/type-2 like mutations and a lowerJAK2V617Fallele burden. EEC growth andCALRmutations conferred favourable overall survival (OS). A lowerJAK2V617Fallele burden and grade 3 bone marrow fibrosis were associated with shorter OS and decreased leukaemia-free survival (LFS). Type 2/type 2-likeCALmutations were associated with better LFS compared with type1/type 1-like mutations. Patients with triple-negative mutation status had significantly worse OS and LFS. The allele burden ofCALRmutations remained unchanged, while someJAK2V617Fmutations showed clonal expansion in patients during secondary acute myeloid leukaemia transformation.

Conclusions

Our study showed that EEC growth, a higherJAK2V617Fallele burden andCALRmutations, especially type 2, were independent predictors for better outcomes in PMF. The allele burden ofCALRmutations remained stable, but the allele burden ofJAK2V617Fmutations was variable during leukaemia transformation.