bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of ultrasound‐guided vascular access in dogs
Authors: Chamberlin Scott C. , Sullivan Lauren A. , Morley Paul S. , Boscan Pedro 
Published: October 2013

AbstractObjectiveTo describe the technique and determine the feasibility, success rate, perceived difficulty, and time to vascular access using ultrasound guidance for jugular vein catheterization in a cardiac arrest dog model.DesignProspective descriptive study.SettingUniversity teaching hospital.AnimalsNine Walker hounds.Measurements and Main ResultsA total of 27 jugular catheterizations were performed postcardiac arrest using ultrasound guidance. Catheterizations were recorded based on the order in which they were performed and presence/absence of a hematoma around the vein. Time (minutes) until successful vascular access and perceived difficulty in achieving vascular access (scale of 1 = easy to 10 = difficult) were recorded for each catheterization. Mean time to vascular access was 1.9 minutes (95% confidence interval, 1.1–3.4 min) for catheterizations without hematoma, versus 4.3 minutes (1.8–10.1 min) for catheterizations with hematoma (P = 0.1). Median perceived difficulty was 2 of 10 (range 1–7) for catheterizations without hematoma, versus 2 of 10 (range 1–8) for catheterizations with hematoma (P = 0.3). A learning curve was evaluated by comparing mean time to vascular access and perceived difficulty in initial versus subsequent catheterizations. Mean time to vascular access was 2.5 minutes (1.0–6.4 min) in the initial 13 catheterizations versus 3.3 minutes (1.5–7.5 min) in the subsequent 14 catheterizations (P = 0.6). Median perceived difficulty in the first 13 catheterizations (3, range 1–8) was significantly greater (P = 0.049) than median perceived difficulty in the subsequent 14 catheterizations (2, range 1–6).ConclusionsUltrasound‐guided jugular catheterization is associated with a learning curve but is successful in obtaining rapid vascular access in dogs. Further prospective studies are warranted to confirm the utility of this technique in a clinical setting.
Use of Implementation Theory: A Focus on PARIHS
Authors: Ullrich Philip M. , Sahay Anju , Stetler Cheryl B. 
Published: October 2013

ABSTRACTBackgroundLimited understanding and application of theory in implementation research contributes to variable effectiveness of implementation studies. Better understanding of direct experiences with theory could improve implementation research and the potency of interventions.AimsThis study was a conceptual exercise aimed at characterizing experiences with and applications of the Promoting Action on Research Implementation in Health Services (PARIHS) framework.MethodsThis was a structured, qualitative study involving document reviews and interviews used to answer the following overarching questions about nine implementation research centers: Why and how was PARIHS used? What strengths and weaknesses were identified for PARIHS?FindingsPARIHS was being used for varied purposes, at varied levels, in varied ways, and to a varying extent within and across centers. Lack of implementation theory use in investigators’ early years was common. Variability in the nature of theory use was attributable to characteristics of the centers, individual investigators, and features of PARIHS. Strengths and weaknesses of the PARIHS framework were identified.Linking Evidence to ActionThe study provides information to researchers and theorists about the use of one well‐known implementation framework. The information suggests areas for improvements in PARIHS as well as theory use in general, and should assist in the development of theory‐based programs of research.
Modulation of stimulus‐specific adaptation by GABAA receptor activation or blockade in the medial geniculate body of the anaesthetized rat
Authors: Duque Daniel , Malmierca Manuel S. , Caspary Donald M. 
Published: October 2013

Key points
Neurons in the medial geniculate body (MGB), the auditory thalamus, give stronger responses to rare sounds than to repetitive sounds, a phenomenon referred to as stimulus‐specific adaptation (SSA).
The present study sought to elucidate how the inhibitory thalamic circuitry acting at GABAA receptors affects the generation and/or modulation of SSA from recordings of single unit responses from MGB. Microiontophoretic application of GABAergic agonists selectively increased SSA indices, whereas application of antagonists selectively reduced SSA values.
We found that GABAA‐mediated inhibition did not generate the SSA response but regulated the magnitude of SSA sensitivity in a gain control manner.
These findings advance our understanding of the role of inhibition in coding deviance detection in the MGB.
AbstractStimulus‐specific adaptation (SSA), which describes adaptation to repeated sounds concurrent with the maintenance of responsiveness to uncommon ones, may be an important neuronal mechanism for the detection of and attendance to rare stimuli or for the detection of deviance. It is well known that GABAergic neurotransmission regulates several different response properties in central auditory system neurons and that GABA is the major inhibitory neurotransmitter acting in the medial geniculate body (MGB). The mechanisms underlying SSA are still poorly understood; therefore, the primary aim of the present study was to examine what role, if any, MGB GABAergic circuits play in the generation and/or modulation of SSA. Microiontophoretic activation of GABAA receptors (GABAARs) with GABA or with the selective GABAAR agonist gaboxadol significantly increased SSA (computed with the common SSA index, CSI) by decreasing responses to common stimuli while having a lesser effect on responses to novel stimuli. In contrast, GABAAR blockade using gabazine resulted in a significant decrease in SSA. In all cases, decreases in the CSI during gabazine application were accompanied by an increase in firing rate to the stimulus paradigm. The present findings, in conjunction with those of previous studies, suggest that GABAA‐mediated inhibition does not generate the SSA response, but can regulate the level of SSA sensitivity in a gain control manner. The existence of successive hierarchical levels of processing through the auditory system suggests that the GABAergic circuits act to enhance mechanisms to reduce redundant information.
Simplified Correlation Equations of Heat Transfer Coefficient During Phase Change Flow Inside Tubes Filled With Porous Media
Authors: Hammad M. , Tarawneh M. , Al-Shqirate A. 
Published: October 2013

In this work an easy to use, simple and direct equations were formulated and tested. Heat transfer coefficients of phase change fluid flow were examined in this work. The considered fluid flow encountered convection heat flux inside rigid tubes filled with porous media. During the flow, phase change was assumed. Experimental work was conducted using Carbon dioxide as fluid.
An analytical method using exponential non dimensional analysis was used. The Buckingham π theorem and method of indices was used to obtain simplified formula for the convection heat transfer coefficient and for the Nusselt number.
Two different correlations can be extracted from this formula; one for the evaporation process and the other for the condensation process.
The Joint Biomechanics Change by Different Anterior Cruciate Ligament Constitutive Models Under Axial Torque Load
Authors: Wan Chao , Hao Zhixiu , Wen Shizhu 
Published: October 2013

According to the previous papers, it was demonstrated that anterior cruciate ligament (ACL) played an important role in resisting the coupled anterior-posterior laxity rather than the rotation laxity under axial torque load of knee joint. In the biomechanics simulation research of knee joint, some different ligament constitutive models were presented to describe the ACL material behavior. However, there is few published paper to study the effect of variable ligament constitutive model on the joint biomechanics under axial torque load.
In this paper, a 3-dimension finite element model of an intact tibiofemoral joint including all the main anatomical structures was reconstructed and two ACL constitutive models were compared under 10 Nm femur external torque load. The two ACL constitutive models corresponded to an isotropic hyperelastic model and a transversely isotropic hyperelastic model considering fiber effect, respectively. All the ACL material properties of the two constitutive models were defined by fitting the same stress-strain data. Another model with ACL resected was also analyzed under the same load to estimate the function ACL played under joint axial torque load.
It was found that the resection of ACL changed the knee joint deformations significantly in all directions except the distal-proximal translation. In the ACL resected joint model, the internal-external rotation, anterior-posterior and medial-lateral translations increased by about 20%, 500% and 600%, respectively. Comparing to the ACL intact joint model, the Mises stress values of medial collateral ligament decreased while that on lateral collateral ligament increased greatly (from 35 MPa to 61 MPa). In the comparison of the two different ACL constitutive models, the internal-external rotation, as the highest deformation of the knee joint, changed by about 11% and the maximal deformation alteration was obtained in the anterior-posterior translation (about 80%). Both the highest stress value and distribution on ACL have altered mostly while the Mises stress distributions of other ligaments and menisci have changed slightly.
The alteration of joint kinematics and ligament biomechanics by different ACL constitutive models would be due to the different descriptions of the material transverse behavior and the real complex ACL stress distribution under an axial torque load, although the longitudinal material behaviors described by different ACL constitutive models were almost the same based on the same experiment data.
Intelligent Combination of Batch Fabrication With Rapid Prototyping Techniques for a Drop-on-Demand Microdrop Generator
Authors: Kagerer Markus , Eiler Kenji L. , Irlinger Franz , Lueth Tim C. 
Published: October 2013

A fluidic experimentation platform, consisting of a piezoelectrically driven microdrop generator which is mounted on a quick-action clamping device, is introduced. Microdrop generators are playing an increasingly important role in many industries. Even though their beginnings were in the printing and coating sector, their strengths are more and more used in other sectors. The wide variety of properties of the fluids like molten polymers, dispersions, or monomers usually require a redesign of the microdrop generator for each application to achieve drops of the size, with the speed, and uniformity that are needed. Therefore, the use of rapid prototyping (RP) techniques for the adaption of microdrop generators to new boundary conditions is indispensable.
The presented microdrop generator is based on the diaphragm design. A silicon base plate includes the fluidic components. The number of nozzles is three. Even if one nozzle is clogged two other nozzles are working. The diaphragm is made of borosilicate glass. On top of the diaphragm a piezoelectric transducer is glued. The piezoelectric transducer and the diaphragm form a bimorph actuator. Since only the borosilicate glass and the silicon are in contact with the fluid the assembly is highly chemical resistant to aggressive media. Thus, a very broad range of fluids is ejectable.
Besides the laser as main tool a dicing saw is involved in the process flow. Investigations for the optimum machining parameters are presented. In this project four equal microdrop generators respectively 12 nozzles and one further silicon base plate for further quality inspection of the whole batch are manufactured simultaneously. They serve as a good basis for fluidic experiments. Only six process steps are necessary to fabricate one microdrop generator within 25 min. Up to 16 microdrop generators can be batch fabricated in a 4″ process chain with rapid prototyping techniques.
The realized quick-action clamping device supports a rapid exchange of the microdrop generators and enables future technologies. Here, the electrical and the fluidic connection of the microdrop generator are realized. The microdrop generator is inserted into a groove and is at the same time fluidically and electrically connected via four spring contacts. Special feature is that no gluing or soldering processes are necessary. The device is constructed in a modular way to add further components like a heating cartridge or a fluid reservoir. Overall, the exchange of one microdrop generator can be realized within one minute.
The use of the batch fabricated microdrop generator in combination with the presented quick-action clamping device guarantees an efficient execution of fluidic experiments.
A Study of the Mechanical Role of Enamel and Dentin in Human Teeth
Authors: Chun Keyoung Jin , Choi Hyun Ho , Lee Jong Yeop 
Published: October 2013

The dental hard tissues of a tooth are combined of enamel and dentin together. The enamel protects the dentin and comes in direct contact with food during mastication. Bite force is expressed as compression force. The purpose of this study is to identify the primary roles of enamel and dentin during mastication by analyzing their mechanical properties and hardness.
Healthy human teeth (age: 19.3 ± 4.1) were used as specimens for mechanical tests. The teeth, which underwent epoxy resin molding, were machine cut to make 10 enamel specimens, 10 dentin specimens and 10 enamel–dentin composite (ED) specimens of 1.2 mm × 1.2 mm × 3.0 mm (Width × Height × Length) in size. Compression tests were conducted using a micro-load system at 0.1 mm/min test speed.
Teeth surface hardness (HV) was measured by a Vickers diamond indenter with a 300g indentation load. Data were obtained from 4 points on each enamel specimen and 4 points on each dentin specimen.
The strain (%), stress (MPa) and modulus of elasticity (E, MPa) of the specimens were obtained from compression tests. The MAX. strain of the enamel, dentin and ED specimens were 4.5 ± 0.8 %, 11.9 ± 0.1 % and 8.7 ± 2.7 %, respectively. The MAX. stress of the enamel, dentin and ED specimens were 62.2 ± 23.8 MPa, 193.7 ± 30.6 MPa and 126.1 ± 54.6 MPa, respectively. The E values of the enamel, dentin and ED specimens were 1338.2 ± 307.9 MPa, 1653.7 ± 277.9 MPa and 1628.6 ± 482.7 MPa, respectively. The E of the dentin specimens was the highest and the E of the enamel specimens was the lowest, but the E values of all specimens was not significantly different in the T-test (P > 0.1). The measured hardness value of the enamel specimens (HV = 274.8 ± 18.1) was about 4.2 times higher than that of the dentin specimens (HV = 65.6 ± 3.9).
Because of the values of MAX. stress and MAX. strain of the enamel specimens, the enamel specimens tended to fracture earlier than the dentin and ED specimens; therefore, enamel was considered to be more brittle than dentin and ED. Enamel is a harder tissue than dentin based on their measured hardness values. Therefore, enamel has a higher wear resistance, making it suitable for grinding and crushing, whereas dentin has a higher force function, making it suitable for abutment against bite force.
Open Design of High Pressure Ratio Radial-Inflow Turbine for Academic Validation
Authors: Sauret Emilie 
Published: October 2013

Computational Fluid Dynamics (CFD) simulations are widely used in mechanical engineering. Although achieving a high level of confidence in numerical modelling is of crucial importance in the field of turbomachinery, verification and validation of CFD simulations are very tricky especially for complex flows encountered in radial turbines. Comprehensive studies of radial machines are available in the literature. Unfortunately, none of them include enough detailed geometric data to be properly reproduced and so cannot be considered for academic research and validation purposes. As a consequence, design improvements of such configurations are difficult. Moreover it seems that well-developed analyses of radial turbines are used in commercial software but are not available in the open literature especially at high pressure ratios.
It is the purpose of this paper to provide a fully open set of data to reproduce the exact geometry of the high pressure ratio single stage radial-inflow turbine used in the Sundstrand Power Systems T-100 Multipurpose Small Power Unit. First, preliminary one-dimensional meanline design and analysis are performed using the commercial software RITAL from Concepts-NREC in order to establish a complete reference test case available for turbomachinery code validation. The proposed design of the existing turbine is then carefully and successfully checked against the geometrical and experimental data partially published in the literature. Then, three-dimensional Reynolds-Averaged Navier-Stokes simulations are conducted by means of the Axcent-PushButton CFD® CFD software. The effect of the tip clearance gap is investigated in detail for a wide range of operating conditions. The results confirm that the 3D geometry is correcty reproduced. It also reveals that the turbine is shocked while designed to give a high-subsonic flow and highlight he importance of the diffuser.
Efficiency Enhancement of a Small Scale Closed Solar Thermal Brayton Cycle by a Combined Simple Organic Rankine Cycle
Authors: Riazi H. , Ahmed N. A. 
Published: October 2013

In this paper efficiency enhancement of a small scale closed solar thermal Brayton cycle is investigated by combining it to a simple organic Rankine cycle. Brayton power cycles are generally known as the enabling technology for high temperature solar power towers due to their higher efficiencies compared to other power cycles. Unlike conventional solar-thermal plants, which concentrate the sun’s energy to generate steam for driving a turbine, the Brayton thermodynamic does not use water. Instead, the concentrated solar energy is used to heat compressed air, which then expands through a gas turbine to generate power. Irreversible loss in compressor and turbine, the operating temperature of solar collector and recuperator effectiveness are the main features that limit the net power output of the system which should be considered and analyzed. The exhaust of the gas turbine is still at high temperature that should be cooled down before entering the compressor. Thus, this heat can be utilized to operate a low temperature Rankine cycle and increase the system efficiency and power generation.
Operating points of off the shelf micro-turbines and steam turbine with parabolic solar dish concentrator of various concentrating ratios are considered. Thermodynamic analysis is applied, by using the first and second law of thermodynamics, to obtain the optimum temperature of solar collector, minimum irreversibility rates to maximize the efficiency and net power output of the system at various steady-state conditions.
Results show that for the closed solar thermal Brayton cycle the maximum overall first law efficiency of the system can be increased of more than 5% by combining a simple Rankine cycle to recover the exhaust heat and a significant 20% increase in the second law efficicency. The system efficiency is related to the solar concentration ratio with an optimum operating temperature and the choice of micro-turbine. On this basis, both the overall efficiency and the total output power may reach their maximum value by optimizing the pressure ratio. In a small scale closed solar thermal Brayton cycle combined by a Rankine cycle with a micro turbine operating at its highest compressor efficiency, the operating conditions can be optimized in such a way that the system produces maximum net power output or having the highest overall efficiency.
Development of a Materials for Energy Storage Course for Engineering Students
Authors: Corneal Lindsay M. 
Published: October 2013

The advanced energy storage industry is a rapidly growing field. This industry is looking for engineering graduates with the skills and training to work in the area of energy storage. The School of Engineering at Grand Valley State University is developing a three-course certificate in advanced energy to address this need. The objective of the certificate is to prepare students with a sound engineering and science education which is augmented with knowledge of energy as applied to advanced energy storage for electrified vehicles and power management.
As part of the certificate in advanced energy, a course is being developed in Materials for Energy Storage. This course will study the components of electrochemical cells and the various materials used for these components. The focus will be on the properties of the different materials, the benefits and drawbacks of each one, and the selection of materials for specific applications. The interaction between the materials of the individual components within the cells will be examined. Finally, the electrochemical energy storage system will be considered as a whole and the testing and performance of the cells will be studied.
This paper will present a description and overview of the course, and the topics that will be covered. As the course is in the development stage, the plans for assessment after its pilot offering will be discussed.
Extending Blind Modal Identification to the Underdetermined Case for Ambient Vibration
Authors: McNeill Scot 
Published: October 2013

The modal identification framework known as Blind Modal Identification (BMID) has recently been developed, drawing on techniques from Blind Source Separation (BSS). Therein, a BSS algorithm known as Second Order Blind Identification (SOBI) was adapted to solve the Modal IDentification (MID) problem. One of the drawbacks of the technique is that the number of modes identified must be less than the number of sensors used to measure the vibration of the equipment or structure.
In this paper, an extension of the BMID method is presented for the underdetermined case, where the number of sensors is less than the number of modes to be identified. The analytic signal formed from measured vibration data is formed and the Second Order Blind Identification of Underdetermined Mixtures (SOBIUM) algorithm is applied to estimate the complex-valued modes and modal response autocorrelation functions. The natural frequencies and modal damping ratios are then estimated from the corresponding modal auto spectral density functions using a simple Single Degree Of Freedom (SDOF), frequency-domain method. Theoretical limitations on the number of modes identified given the number of sensors are provided.
The method is demonstrated using a simulated six DOF mass-spring-dashpot system excited by white noise, where displacement at four of the six DOF is measured. All six modes are successfully identified using data from only four sensors. The method is also applied to a more realistic simulation of ambient building vibration. Seven modes in the bandwidth of interest are successfully identified using acceleration data from only five DOF. In both examples, the identified modal parameters (natural frequencies, mode shapes, modal damping ratios) are compared to the analytical parameters and are demonstrated to be of good quality.