bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Saline Injection to Create Large Thermal Lesions During Radio Frequency Ablation Therapy: 2. Experimental Results
Authors: Silver Lissa P. , Hamilton Patrick S. , Ni Angela C. , Aimi Roberto M. , Curley Michael G. 
Published: November 2021

Abstract
Tissue charring during radio frequency (RF) therapy causes an impedance rise and prevents further tissue heating from occurring, thereby limiting the size of lesions that can be created. The ability to create very large lesions would provide minimally invasive treatment options for deep tissue left ventricular arrythmias and otherwise-untreatable large liver tumors. Adding convection as a method of heat transfer by injecting saline at the RF electrode site acts to both clamp the electrode/tissue interface temperature and carry energy deeper into the tissue. We have developed a RF system that uses both conduction and convection simultaneously to both enhance the amount of heat transfer and prevent or greatly delay the onset of charring. Here we confirm the heat transfer augmentation of convection with experimental results in skeletal muscle, liver, and myocardium.
Comparison of Silver/Silver Chloride, Platinum, and Stainless Steel As Materials for Radio-Frequency Ablations
Authors: Silver Lissa P. , Hamilton Patrick S. , Curley Michael G. 
Published: November 2021

Abstract
Tissue charring during radio frequency (RF) therapy causes an impedance rise and prevents further tissue heating from occurring. Charring can be exacerbated by electrochemical surface heating at electrode/tissue interfaces. Using electrode materials that have equal surface and bulk heating rates would be ideal to obtain maximum bulk heating before the onset of charring.
Here we compare the surface-to-bulk heating characteristics of silver/silver chloride (Ag/AgCl), platinum (Pt), and stainless steel (SS) during RF energy application in an effort to determine which material is best suited for RF ablation therapies.
Evaluation of Freezing Effects on Human Microvascular-Endothelial Cells (hMEC)
Authors: Berrada Marwane S. , Bischof John C. 
Published: November 2021

Abstract
There is mounting evidence that the endothelium may play an important role in traditional cryosurgical treatments by acting to locally foster thrombi in the microvasculature of various tissues after freezing. Therefore, this study was designed to investigate, at the cellular level in human microvascular endothelial cells (hMEC), the various biophysical changes that occur during freezing and compare them with post-freeze viability. The hMECs were loaded on a cryomicroscope stage and freezing experiments at 5, 10, 15, 25, 100 and 130°C/min were performed to experimentally evaluate dehydration (water transport) as well as intracellular ice formation (IIF) within this cell system. The dehydration kinetics were found to be governed by a membrane permeability Lpg and activation energy ELp of 0.05 (μm/min.atm) and 14.8 (kcal/mole) respectively [R2 = 0.94]. These parameters were then tested for predictive ability against the experimentally measured behavior at 15°C/min with a good agreement [R2 = 0.98]. Intracellular Ice Formation (IIF) was found to occur at lower temperatures than many cell types (i.e. TIIF 50% ∼ −18°C) and at cooling rates greater than or equal to 25°C/min. At cooling rates above 50°C/min, two types of IIF, cell darkening and twitching, were both observed and quantified and were assumed to be governed by Surface Catalyzed Nucleation (SCN). IIF parameters Ωo, and κo were found to be 6.8 × 10−8 (m2.s)−1 and 8.3 × 10−9 (K5) [R2 = 0.94] respectively. Viability results suggest an inverted U-shape curve between 1 and 50°C/min (with a maximum at 10°C/min). But viability appears to increase again at cooling rates &gt; 50°C/min (i.e. it does not continue to drop) which suggests that the traditional two factor hypothesis may not completely describe viability in this system. Additional cellular destruction was found by lowering the end-temperature to −30°C or below. At this temperature the majority of the cell population was destroyed regardless of the cooling rate.
Modeling the Thermal Histories of Collagenous Tissues Subjected to Different Heating Modalities
Authors: Aksan Alptekin , Nielubowicz David S. , McGrath John J. 
Published: November 2021

Abstract
Application of sub-ablative levels of heat to collagenous tissues causes helix-to-coil transformation in the collagen microstructure resulting in overall tissue shrinkage. This phenomenon has important therapeutic applications in medicine, such as thermokeratoplasty, treatment of shoulder, knee and ankle instabilities and treatment of chronic discogenic lumbar pain associated with herniated discs. During the therapy, heat is applied arthroscopically by a laser or a radio-frequency probe (bipolar or monopolar). The amount and permanence of shrinkage established in the tissue is a function of the maximum temperature reached and the exposure time as well as the mechanical stress applied on the tissue during heating. Therefore, the thermal and mechanical history that the tissue experiences is a major factor determining its response and long-term mechanical stability. These are the defining factors for the success of the therapy. It is hypothesized in this study that there are significant differences between the thermal histories created in the tissue by different heating modalities owing to the differences between their modes of action. The solutions to the temperature distributions created by these different heating modalities — laser and radiofrequency applied with a bipolar and a monopolar probe — are compared and parameters of clinical significance are discussed.
Creation, Development, and Approval of Design, Build, and Test Senior Design Projects
Authors: Dave Janak , Boronkay Thomas G. 
Published: November 2021

Abstract
Completing a Senior Design Project is a graduation requirement for all the students in the Mechanical Engineering Technology (MET) Department at the University of Cincinnati. The project consists of a four-course sequence resulting in a working product. This group of courses is designed to help students synthesize and apply the knowledge and skills they have acquired prior to their senior year. It also makes them use their abilities to solve open-ended problems and prepares them for the transition to a non-academic environment. The completed projects are assessed by a team of practicing engineers during the Technical Exposition Day (Tech Expo). This paper describes the process which all students must go through to complete their senior capstone design projects with design, build, and test requirements.
Design-Build-Test Senior Design Project
Authors: Boronkay Thomas G. , Dave Janak 
Published: November 2021

Abstract
Every student in the Mechanical Engineering Technology Department must complete a Senior Capstone Design Project course sequence as a requirement for the partial fulfillment of the Bachelor of Science in Mechanical Engineering Technology degree. Mechanical Engineering Technology students at the University of Cincinnati must design, build, and test their product for the satisfactory completion of the Senior Design Project course sequence. At many institutions the capstone projects do not include the build and test components.
This paper gives a short description of the Senior Design course sequence, the list of pre-requisite design courses, the design process used by the students to complete their projects. It addresses issues, such as, team versus individual projects, industrial versus personal projects, etc. It also describes typical projects, two of which are being used in industry with minor modifications.
Quantitative Evaluation of an Internal Flaw of a Structural Component Using Electromagnetic Acoustic Transducers
Authors: Maruyama Shinichi , Sugiura Toshihiko , Inoue Akihiro , Yoshizawa Masatsugu 
Published: November 2021

Abstract
Electromagnetic acoustic transducers (EMATs) can transmit and detect ultrasonic waves in a conductive specimen out of any contact with it. This process can be given theoretical modeling and formulation based on elastodynamics and electromagnetics. It suggests a possibility of quantitative nondestructive evaluation using EMATs. This research deals with a numerical method of flaw identification from a receiver signal obtained by EMATs. Experimental results of the receiver signals agree well with numerical ones, which verified the mathematical model of the inspection process. Flaw identification is formulated as a problem of parameter optimization. To avoid being trapped in a local optimum, initial parameters were successfully evaluated from the height and the time period of peaks in the receiver signals. Flaw parameters were identified from the receiver signals obtained by numerical simulations and experiments, which verified the method of flaw identification presented here.
Inspection of Fastener Holes Using Ultrasonic Phased Arrays
Authors: Herzog Pamela G. , Lupien Vincent , Miller James T. , Selman John J. , Moles Michael 
Published: November 2021

Abstract
An Air Force Aging Aircraft Project was initiated to identify a suitable replacement for the Autoscan. The Autoscan is a unique piece of equipment that was originally identified for specific inspections for detection of first-layer, faying surface fatigue cracks (.030″ and larger) around fastener holes beneath the fastener heads, without removal of the fastener. The currently inspected parent material ranges from .125 to .3 inches thick, 2024T3 or 7075-T73 aluminum. Potential also exists for replacing other aging inspection equipment such as the Rotoscan. A secondary objective was to evaluate the feasibility of expanding the inspection capabilities to detect corrosion as well as cracks.
A Trade Study was conducted initially to consider existing technologies available, trade-offs, and technology insertion in order to meet the required performance parameters. The trade study showed Phased Array Ultrasonics to have the greatest potential, so it was chosen as the inspection method to pursue. Using phased arrays, a novel inspection technique for rapidly and reliably inspecting the area around fastener holes for cracks and corrosion has been developed with no moving parts. Specially designed probes are used for the aircraft inspections.
This design consists of a three-dimensional matrix of 504 ultrasonic elements on a cone that encircles the fastener head. The two-dimensional arrangement of elements permits deflection of the ultrasonic beam in three dimensions. Full circumferential scans are performed by programming the phased array focal laws to scan 360° of the fastener holes, using a combination of the following scan patterns: pulse-echo at 45° incident on the crack, pulse-echo at 90°, pitch-catch, plus local scanning. This capability allows flexible coverage of the fastener hole and surrounding area, again with no moving parts. Additionally, the beam deflection capability means that one probe is adaptable to a wide range of fastener diameters and skin thickness.
Several conical sub-arrays were built to evaluate the feasibility of the concept experimentally. The experimental results along with numerical modeling were used to determine optimal values for inner and outer radii of the cone, angle of the cone, number of elements and arrangement of the elements. A complete prototype conical array was subsequently built.
The final portion of this project includes developing the specific inspection procedures, and performing a Probability of Detection study (POD) developed by the FAA’s Airworthiness Assurance Nondestructive Tested Validation Center at Sandia National Laboratory.
Effect of Corrosion Damage on Fatigue Behavior of Al 2024
Authors: Khobaib Mohammad , Donley Michael S. 
Published: November 2021

Abstract
Fatigue crack nucleation from corrosion damage is drawing considerable attention in the aging aircraft research community. Localized corrosion, such as corrosion pits, is a potential stress raiser and provides active sites for fatigue crack initiation. The detailed knowledge of the metrics of early stages of corrosion damage and transition to fatigue cracks is critical to the accurate life prediction of the structure. High strength aluminum alloys are known to be very sensitive to orientation and this could play a critical role in both pitting and the resulting fatigue damage.
Fatigue experiments on dog bone specimens of Al 2024-T3 with known pit morphology were conducted to investigate the crack initiation and growth behaviors of cracks nucleating from pits. The corrosion pits were grown electrochemically in a controlled fashion and samples were prepared with pit depth varying from 3 to nearly 130 μm. These pits were characterized using white light interferometer; surface parameters such as average roughness and morphology were determined before fatigue testing. Specimens were aligned in three different directions, L-T, T-L and L-S to investigate the effect of orientation on pitting and fatigue characteristics.
The fatigue lives were observed to decrease with increasing pit depth. The fractured surface was analyzed after the fatigue test and stress intensity calculations were made based on these observations. A linear relationship between stress intensity factor and critical pit depth was observed. The crack growth behavior of the crack nucleating from these pits was typical of a short crack. The results provide the details of the critical pit size that can lead to fatigue crack initiation as well as supply information about the growth behavior of cracks nucleating from corrosion pits. An understanding of the role of pitting in crack initiation aids in extending the fatigue life of the aging aircraft.
Numerical Analysis of the Flow Inside a Centrifugal Compressor’s Vaneless Diffuser and Volute
Authors: Rezaei Hooman , Engeda Abraham , Haley Paul 
Published: November 2021

Abstract
The objective of this work was to perform numerical analysis of the flow inside a modified single stage CVHF 1280 Trane centrifugal compressor’s vaneless diffuser and volute. Gambit was utilized to read the casing geometry and generating the vaneless diffuser. An unstructured mesh was generated for the path from vaneless diffuser inlet to conic diffuser outlet. At the same time a meanline analysis was performed corresponding to speeds and mass flow rates of the experimental data in order to obtain the absolute velocity and flow angle leaving the impeller for those operating conditions. These values and experimental data were used as inlet and outlet boundary conditions for the simulations. Simulations were performed in Fluent 5.0 for three speeds of 2000, 3000 and 3497 RPM and mass flow rates of minimum, medium and maximum. Results are in good agreement with the experimental ones and present the flow structures inside the vaneless diffuser and volute.
Forced Convective Heat Transfer From Helicoidal Pipes
Authors: Fakheri Ahmad , Alnaeim Abdelrahman H. A. 
Published: November 2021

Abstract
Forced convection heat transfer from helicoidal pipes is experimentally investigated over a wide range of operating conditions. Based on the experimental results, a characteristic length incorporating the tube diameter, the coil diameter, and the coil spacing, is proposed as the relevant scale for defining Nusselt and Reynolds numbers. Based on this characteristic length, Nusselt number for helicoidal pipes can be predicated from the correlations available for cylinders in the range of available experimental data. It is shown that the performance of the coils depends on the Reynolds number. At high Reynolds numbers, the heat transfer coefficient is essentially equal to that of the straight pipe and the coil pitch has little influence on the heat transfer rate. On the other hand, at low Reynolds numbers, the heat transfer coefficient is lower than that of a straight pipe and its value is a strong function of the coil spacing.
Heat and Mass Transfer Characteristics of a Finned-Tube Evaporator Under Frosting Conditions
Authors: Kim Y. H. , Park Y. J. , Kim Y. C. , Shim S. C. , Oh S. K. , Lee J. S. 
Published: November 2021

Abstract
An experimental study was performed to investigate the heat and mass transfer characteristics of a finned-tube evaporator coil utilized in a domestic refrigerator under frosting conditions. Airside heat transfer coefficient was measured as a function of air temperature, humidity ratio, air velocity, and evaporating temperature. In addition, frost thickness was monitored and measured by visualization tests during frosting operation. Based on the experimental results, the degradation of heat transfer performance due to frost formation was explored as a function of operating parameters. The rate of frost formation on the evaporator increases at relatively high humidity, high airflow rate, low inlet air temperature and low refrigerant temperature. As the frost thickness increases, airflow rate gradually decreases, while the capacity increases at the early stage of frost formation and then significantly drops.
Understanding and Operating Pretreatment Systems
Authors: Easton Jeff 
Published: November 2021

Abstract
As demand for high and ultra pure water increases, enhanced performance from pretreatment systems become more and more necessary. When operated at full potential, pretreatment systems can greatly improve downstream unit processes, however many pretreatment systems become a mysterious “black box” that are often neglected. Proper training and understanding of the intricacies of pretreatment variables and constraints is a valuable resource for any system operator.
This paper discusses the application of true solids contact clarification and multi-media filtration in lime softening and turbidity reduction applications. Basic mechanical and process features as well as testing, instrumentation and control parameters will be covered. Terminology and analysis techniques for optimization will be introduced. The objective of this paper is to give the plant operator the understanding necessary to optimize the effluent quality and operability of the solids contact clarifier and multi-media filter pretreatment system.
Hollow Fiber Microfiltration and Ultrafiltration Products for High Purity Water Treatment Applications
Authors: Wenthold Randal M. 
Published: November 2021

Abstract
For years in the semiconductor inductor industry the only choice individuals had for microfiltration or ultrafiltration devices consisted of flat sheet membrane manufactured into spiral wound or pleated filtration products. Polysulfone hollow fiber technology has evolved in the medical device industry for use as the highest purity type filtration device available. This unique technology is now available for use in the semiconductor business segment as well with product offerings that may be used in laboratory to large-scale applications.
Recent Developments in High-Performance Refrigeration for the First Compact Cryogenic Freeze-Dryer
Authors: Reznikov L. , Sutherland D. 
Published: November 2021

Abstract
Lyophilization, a process of drying of frozen materials with sublimation of solvents from frozen products, is one of the key processes in pharmaceutical industry for preparation of dry inert products. Traditionally, refrigeration for operations of freezing, primary and secondary drying of the moist products and for condensing of solvents has been supported by mechanical refrigeration.
Development of efficient, reliable cryogenic refrigeration with accurate temperature control and effective heat transfer processes have created premises for design of the first in the world cryogenic pump-free compact unit “Advantage LN2”.
A Study of the Lateral Stability of Railroad Vehicles Using a Nonlinear Constrained Multibody Formulation
Authors: Valtorta Davide , Zaazaa Khaled E. , Shabana Ahmed A. , Sany Jalil R. 
Published: November 2021

Abstract
The lateral stability of railroad vehicles travelling on tangent tracks is one of the important problems that has been the subject of extensive research since the nineteenth century. Early detailed studies of this problem in the twentieth century are the work of Carter and Rocard on the stability of locomotives. The linear theory for the lateral stability analysis has been extensively used in the past and can give good results under certain operating conditions. In this paper, the results obtained using a linear stability analysis are compared with the results obtained using a general nonlinear multibody methodology. In the linear stability analysis, the sources of the instability are investigated using Liapunov’s linear theory and the eigenvalue analysis for a simple wheelset model on a tangent track. The effects of the stiffness of the primary and secondary suspensions on the stability results are investigated. The results obtained for the simple model using the linear approach are compared with the results obtained using a new nonlinear multibody based constrained wheel/rail contact formulation. This comparative numerical study can be used to validate the use of the constrained wheel/rail contact formulation in the study of lateral stability. Similar studies can be used in the future to define the limitations of the linear theory under general operating conditions.
Top of Rail Lubrication Pilot Project Results on Wheeling and Lake Erie Railway
Authors: Clapper Jeff , Dyavanapalli Venkat , Kumar Sudhir , Wolf Eric 
Published: November 2021

Abstract
A pilot project was conducted by the Wheeling and Lake Erie Railway to verify some of the benefits of TracGlide, a Top of Rail Lubrication (TOR) system originally developed by Tranergy Corporation and produced now by Friction Management Services (FMS). Friction Management Services is a joint venture between Timken Company and Tranergy. The primary objective of the project was to determine the fuel savings/increased productivity of a train. Tests were conducted using a loaded aggregate train between Brewster, OH and Spencer, OH, a 37.8 mile; 40 mph-track. The system and lubricant evolved over a period of five years from analytical solution, design and prototyping, to production, field-testing and demonstration. Based on extensive field-testing, energy savings can be achieved by railroads using this system.
A Comparison of Railroad Axle Stress Results Using Different Design Sizes, Loading Criteria and Analysis Methods
Authors: Dedmon Steven L. , Pilch James M. , Lonsdale Cameron P. 
Published: November 2021

Abstract
Although railroad axles do not often fail in North American freight service, they remain a critical component. This paper presents the results of stress analysis calculations that were performed for various different North American freight railroad axle designs. Loading criteria appropriate for the various axle designs were used, and different methods of axle stress analysis are compared and contrasted. Results are reviewed and discussed. Also, the authors propose that a standard axle stress analysis method be adopted by the North American freight railway industry for new axle designs, particularly for those axles to be used at increased gross rail loads (GRL).