bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Structure on Brittleness of Boron Nitride Coatings Deposited on Cemented Fine-Grained Carbides
Authors: Kupczyk Maciej Jan , Siwak Piotr 
Published: July 2011

Abstract
The article presents the brittleness study of boron nitride coatings deposited on cutting edges made of fine-grained cemented carbides by the pulse-plasma method (PPD). Influences of the structure (density, pores, microcracks) of coating material on the brittleness and on selected technological parameters of boron nitride formation by PPD method particularly taking into account discharge voltage on brittleness are shown. Differences between values of total average crack length ΣL, critical loads (Pk300, Pk500), and coefficients (a1(300) and a1(500)) characterized susceptibility to cracking of investigated coatings manufactured using different values of production process were defined. Results of investigations have confirmed the usefulness of Palmqvist’s method for measurement of coating susceptibility to brittle cracking.
Impact Wear Performance of Thin Hard Coatings on TiC Cermets
Authors: Veinthal Renno , Sergejev Fjodor , Emrah Yaldiz Can , Mikli Valdek 
Published: July 2011

Abstract
During metal forming processes like deep drawing of steel, tools are subjected to various loads. Besides adhesion, abrasion, and tribo-oxidation, successive impacts during forming induce Herzian contact pressures and cause fatigue failure. The present study focuses on TiC-based composites with Ni/Mo binders and thin coatings (TiN, (Ti,Al)N, TiCN, nc-(Al,Ti)N/α-Si3N4) produced by the physical vapor deposition technique. The adhesion of the coatings was characterized by Rockwell test and nanoscratch tests in single- and multi-scratch mode. The impact wear tests were performed using the rotating hammer-type surface fatigue wear tester for single spot testing. The effect of substrate surface roughness on the overall substrate/coating system was investigated. Selected surface contact damage sites in all materials were subjected to close examination by high power optical microscopy. Nanocomposite nc-(Al,Ti)N/α-Si3N4 coatings showed the highest hardness value. In addition, these coatings also have lower modulus values, which make them the best candidate for demanding wear applications. TiCN coatings have the second highest hardness value, but due to poor adhesion qualities, especially at higher roughness values, delamination was found to be present even directly after the coating process without any load. This is assumed to be related to the higher inherent residual stresses of TiCN coatings with TiC–Ni/Mo cermets. In this system the gradient nature of the top layer and presence of more ductile additional layer provide better performance in impact wear conditions.
Dependence of the Heat Transfer Coefficient at Quenching on Diameter of Cylindrical Workpieces
Authors: Liščić Božidar , Singer Saša , Beitz Hartmut 
Published: July 2011

Abstract
For computer simulation of a quenching process, the fundamental prerequisite is to have the relevant heat transfer coefficient (HTC) calculated as function of workpiece’s surface temperature and time respectively. In order to calculate the HTC, experimental measurement of the temperature-time history (cooling curve) near the workpiece surface is necessary. In this investigation, cylindrical probes of 20, 50, and 80 mm diameter are used. The cooling curve was measured always at 1 mm below the surface of the probe. Special care has been taken to keep all other factors (design of the probes, temperature measurement, quenching conditions, and calculation procedure), which can influence on the calculated HTC, constant to assure that the only variable is the diameter of the probe. Supposing a radially symmetrical heat flow at half length of the probe, the HTC was calculated using one-dimensional (1-D) inverse heat conduction method. The unexpected striking result of this investigation is the fact that for biggest probe diameter (80 mm), the calculated HTC as function of surface temperature does not show the film boiling phase. A plausible explanation of this effect is given based on the critical heat flux density. The possibility to establish a simple fixed relation (a correction factor) between the HTC and the diameter of cylinders is discussed.
Polyalkylene Glycols as Next Generation Engine Oils
Authors: Woydt Mathias 
Published: July 2011

AbstractSome of the properties intrinsically present in the backbone of polyalkylene glycols (PAGs), which have nowadays attracted the automotive original equipment manufacturers (OEMs), are presented, such as bio-no-tox properties, heat capacity, extended drains, low friction, low AlSi-liner wear, fuel economy, and very high viscosity indices, and are achieved with metal-, ash-, and polymer-free formulations, which guarantee no adverse contamination of the lambda sensor and the active centers of the catalyzer as well as not to increase the exhaust back pressure of the particulate filter through ash deposits. This paper illuminates the latest results from OEM’s engine bench and road testing supporting the following functional benefits: (a) bio-no-tox, (b) improvements of fuel economy, even when compared with latest hydrocarbon-based prototype oils, (c) reduced wear, (d) reduced engine friction, (e) extended drains, (f) suited for bio-fuels, (g) no adverse effects on after-treatment devices through ash-, metal-, and polymer-free formulations, etc.
Particle Characterization and Sizing: SEM Utilizing Automated Electron Beam and AFA Software for Particle Counting and Particle Characterization
Authors: Herguth William Robert , Nadeau Guy William 
Published: July 2011

Abstract
In recent decades oil analysis laboratories have used automatic particle counters to determine the number and size of particles in many oil wetted systems. Once determined, there has been the question of “what are they?” Logically, the next step is to investigate the make-up of the particles by extracting the particles and analyzing using emission spectroscopy and/or a filter membrane for view them under magnification. Characterizing the make-up of the particles is very useful in determining the source. A cost-effective action plan can be undertaken to rectify the identified problem once the particle type is determined. The problem with these two approaches is; emission spectroscopy analysis is often unreliable in identifying larger particles and; under optical magnification it is not possible to tell for sure the makeup of the particles. In some cases scanning electron microscopy (SEM) analysis is undertaken to further identify the particles. This proves to be time-consuming for the SEM operator and is left to the operator to judge which areas of the sample to investigate. This study illustrates the performance and innovative approach to resolving the aforementioned limitations on sizing and identifying particles using an “Automated Electron Beam Particle Analyzer” equipped with “Automated Feature Analysis” (AFA) software to characterize complex matrix of particles extracted onto a membrane filter from oil samples.
CFD-Simulation of Film Boiling at Steel Cooling Process
Authors: Kulju Timo , Pyykkönen Juha , Martin David C. , Muurinen Esa , Keiski Riitta L. 
Published: July 2011

Abstract
This paper analyzes film boiling phenomena on a flat, horizontal hot steel plate using the volume of fluid method. The influence of water delivery velocity and plate surface temperature on film boiling behaviour has been quantified for the case of a single laminar flow jet assuming two-dimensional radial symmetry. In the present study, the model includes both convection and radiation induced mass and heat transfer, where the latter was found to be more important to maintain the film layer and film boiling at high temperatures. The model estimated heat and mass transfer behaviours at impingement velocities between 1 and 5 m/s and temperatures between 500 and 1300 K were found to be qualitatively consistent with available literature. The initial results obtained with the simulation suggest that computational fluid dynamics (CFD) simulation techniques represent a promising alternative for studying complex and difficult to measure phenomena such as high temperature film boiling, and hint at a new class of experimental methods for mechanistic analysis of fluid mechanical and thermal processes using purely computational methods.
Biomechanical Cyclical Loading on Cadaveric Cervical Spines in a Corpectomy Model
Authors: Cheng Boyle C. , Cook Daniel J. , Cuchanski Mathieu , Pirris Stephen M. , Welch William C. 
Published: July 2011

Abstract
Approved posterior cervical spinal fixation systems have been submitted to the U.S. Food and Drug Administration with results from standardized test protocols from the ASTM. The bench top mechanical studies are designed to minimize biologic and laboratory variability. However, for implant tests such as ASTM F1717 to be more clinically relevant, anatomical and physiologic considerations must be understood. The specific aim of this study was to determine if a human cadaveric cervical spine with a corpectomy and posterior fixation was effective in maintaining stability prior to and following cyclical loading. Six fresh frozen cadaveric human cervical specimens were harvested and prepared. A C5 corpectomy was performed. Posterior cervical instrumentation was implanted from C3 and C7 spanning across the C4–C6 defect. Each specimen followed an established pure moment test protocol to characterize the instrumented spine in flexion extension, lateral bending, and axial torsion at ±2.5 N m and axial compressive loading to 150 N. Subsequently, each specimen was subjected to 10 000 flexion extension cycles. Following the cyclical loading, each specimen was characterized a second time via the same test protocol. Statistical analyses were then performed on the third cycle data between the two pure moment tests. The mean FE bending range of motion (ROM) was 18.0° ± 10.7° prior to the 10 000 cyclical bending protocol. Following cyclical loading, the mean ROM measured 22.0° ± 19.9°. In axial compression, the mean ROM was 4.1 mm ± 1.9 mm prior to cycling and 4.2 mm ± 1.4 mm post-cycling. A statistically significant difference was detected only in the axial torsion mode of loading (p = 0.030). Although the ASTM standard provides consistent test methodologies, biomechanical cadaveric testing remains an important step in the validation of all spinal instrumentation. The pure moment biomechanical cadaveric test protocol for the same construct was capable of detecting significant changes pre- and post-flexion extension fatigue cycling only in the axial torsion mode of loading.
Beryllium Measurement by Optical Fluorescence in Samples Contaminated by Strongly Fluorescent Impurities
Authors: Agrawal Anoop , Adams Lori , Agrawal Akshay , Cronin John P. , Lopez Tonazzi Juan Carlos , Duran Brandy 
Published: July 2011

Abstract
A fluorescence method for determination of beryllium and beryllium oxide particles has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health. The procedure involves dissolution of samples in ammonium bifluoride solution and adding a small aliquot of extract to a basic hydroxybenzoquinoline sulfonate fluorescent dye and measuring itsfluorescence. This method is specific to beryllium and is not affected by the presence of other metals. However, the results from such a method may be compromised by organic fluorescent impurities which have optical characteristics similar to the beryllium-bonded hydroxybenzoquinoline sulfonate. This study demonstrates that such impurities can be effectively removed by activated charcoal without compromising the sensitivity of the method or any other test attributes.
Approaches towards Design of Green Matrices to Formulate Agricultural and Bio-active Materials and Provide Improved Efficacy
Authors: Narayanan Kolazi S. , Patel Jayanti , Jon Domingo , Qu Xin , Zhang Tom 
Published: July 2011

Abstract
Agricultural formulations containing hydrophobic active ingredients and spray solutions are used in aqueous medium. Typical concentrates are formulated as (a) solvent-based emulsifiable concentrates, (b) water-based suspension concentrates, (c) oil-based suspensions, and (d) solid forms like water-dispersible granules form the bulk of agricultural formulations. Efficacy of the active ingredients depends upon the particle/droplet size distribution in the spray solution and it is advantageous to have submicron size distribution with additional protection against wash off. Global awareness and strong regulatory initiative are the driving force for the design of green and environmentally friendly delivery matrices. Following approaches are viable solutions to address the green delivery targets. This paper will address typical examples of solvent pairs to formulate solvent-based formulations; stable micro-emulsion concentrates using all EPA approved (exemption from tolerance) components usable for food-crops. Water-based suspension concentrates with excellent suspensibility were developed by using newly developed polymer composites. Proprietary derivatized vegetable oils were used as self-emulsifying oils to formulate stable concentrates with good emulsification on dilution in water, without having to use conventional emulsifiers. Additional benefit with such compositions would be sustained release capability. Solventless zero volatile organic compounds (VOC) compositions were also developed for end-use applications with acceptable bio-activity by using proprietary polymer surfactant pairs.
Duration of the Transient Nucleate Boiling Process and Its Use for the Development of New Technologies
Authors: Kobasko N. I. 
Published: July 2011

AbstractIn the paper a review of the transient nucleate boiling process duration is widely discussed. It has been established that duration of transient nucleate boiling process is directly proportional to square of the thickness of steel parts and inversely proportional to thermal diffusivity of a material, depends on the configuration of steel parts, liquid properties, and its velocity. The transient nucleate boiling (self-regulated thermal process) is followed by amazing regularities: The surface temperature during nucleate boiling is maintained at the level of the boiling point of the liquid, which is used as a quenchant. During this period, average effective heat transfer coefficients and average generalized Biot numbers and Kondratjev numbers can be found which significantly simplify core cooling time and cooling rate calculations. Using established characteristics of the transient nucleate boiling process, the new intensive quenching (IQ) technologies were developed: IQ-1; IQ-2: IQ-3. In the paper the steel super-strengthening phenomenon and optimal quenched layer, which provides maximal residual compressive stresses at the surface of steel parts, are discussed, which increase service life of products. Instead of oils, plain water is used as a quenchant, environmental conditions are significantly improved.
How Frequency Affects Fatigue Testing of an Artificial Disc With a Viscoelastic Polymer Core
Authors: Blice R. L. , Zimmers K. B. , Linovitz R. 
Published: July 2011

Abstract
The purpose of this study was to determine the highest appropriate test frequency for a viscoelastic total disc replacement (VTDR). Natural intervertebral discs display viscoelastic behavior. Viscoelasticity is the time-dependent property of a material to show sensitivity to the rate of loading or deformation, having stress and strain reactions that are out of phase. If frequency is too high during mechanical testing of a viscoelastic polymer or medical device, the specimen is unable to recover fully before the next load application. Polymers absorb energy with each cycle. Since work (or energy utilized) is defined as the area under the force–displacement curve [Giordano, N. J., College Physics: Reasoning and Relationships, Brooks/Cole Publishing, Pacific Grove, CA, 2010], a frequency increase which decreases displacement will by definition also decrease the energy the polymer is using to achieve that decreased displacement. By reducing both total displacement and energy, a high test frequency would “protect” a viscoelastic device. A frequency of 2 Hz was used to determine the expected response of the VTDR during axial compression testing between 400 and 4000N. The response was defined as mean peak-to-peak displacement of five test cycles after 1000 cycles of preconditioning. Comparative data was collected at test frequencies of 3, 6, and 10 Hz. Displacement and energy utilized decreased with increasing test frequency. There were no significant differences between the viscoelastic responses in tests at 2 and 3 Hz. However, there were significant decreases in displacement and energy utilized at 6 and 10 Hz compared to 2 Hz. Over a 10 × 106 million cycle fatigue test, for this device, the total displacement would be 548 000mm less at 6 Hz and 988 000mm less at 10 Hz compared to 2 Hz. By decreasing the displacement, by definition it decreases the amount of overall work the disc has done when tested at these high frequencies [Giordano, N. J., College Physics: Reasoning and Relationships, Brooks/Cole Publishing, Pacific Grove, CA, 2010]. Viscoelastic devices should not be tested at high frequencies which “protect” the device by reducing the energy the device has to use overall by decreasing the total displacement it sees. To accurately evaluate in vivo behavior, fatigue testing should utilize test frequencies which do not significantly change the device’s viscoelastic response from that experienced at a physiologic loading frequency.
Comparison of Self-Drilling and Self-Tapping Cervical Spine Screws Using ASTM F543-07
Authors: Konz Regina J. , Jensen Laura M. , Kincaid Brian L. 
Published: July 2011

Abstract
ASTM F543-07 is used to evaluate insertion load (Annex A4), driving torque (A2), and axial pullout (A3) characteristics of self-tapping metallic medical bone screws. F543-07 was designed to evaluate screws that utilize a pre-drilled pilot hole and was not intended for self-drilling screws. The objectives of this study were to (1) adapt the F543-07 test methods to allow evaluation of both self-drilling and self-tapping screws and (2) quantify differences in performance between the two screw types. For all three tests (A4, A2, A3) appropriately sized pilot holes were pre-drilled into the surrogate test medium for all the self-tapping screw designs per ASTM F543-07. No pilot holes were created for the self-drilling screws. During the insertion load tests (A4), a constant rotation was applied to the screws under an initial, near-zero axial force state. While monitoring axial load, torque, and displacement, the axial load was gradually increased. The maximum load at which there was a marked increase in torque and displacement on the graph was indicative of the force required to engage the self-drilling or the self-tapping feature. To measure driving torque (A2), a constant rotation was applied. To maintain screw driver–screw contact, a constant-force axial pre-load was required. The axial insertion load, determined during the insertion load testing (A4), was used as the preload for the driving torque testing. Axial pullout testing (A3) measured the axial tensile force required to remove a screw from the test medium. Quantifiable differences in mean insertion load, driving torque, and pullout load were found, demonstrating that these methods are able to discern differences in performance between different screw designs. Finally, this study demonstrated it is possible to adapt the test methods outlined in ASTM F543-07 to evaluate the insertion load, driving torque, and axial pullout performance of self-drilling screws in addition to self-tapping screws.
USDA Programs to Support Development and Use of Biobased Industrial Products
Authors: Bailey Carmela A. 
Published: July 2011

Abstract
Nonfood, nonfeed uses of agricultural and forestry materials offer the best opportunities to realize the full economic potential which agriculture and forestry can play, beyond the traditional food, feed, and fiber markets. U.S. Department of Agriculture (USDA) has a portfolio of programs that support research, development, and commercialization of biobased lubricants as well as other industrial products that can replace petroleum-based products, such as plastics, paints, coatings, and adhesives. The National Institute of Food and Agriculture (NIFA) administers competitive grant programs to support basic and applied research through the Agriculture and Food Research Initiative, and pre-commercialization research is supported through the Small Business Innovation Research program www.nifa.usda.gov. NIFA collaborates with the Department of Energy through joint solicitations for the Biomass Research and Development Initiative, which supports developmental research and demonstration projects. USDA is the lead Federal agency for implementing the BioPreferredSM purchasing program. Many products, including lubricants, have been officially designated as biobased and must be given first preference for purchase by Federal agencies, thus creating a tremendous market pull for new products through the purchasing power of the Federal government. This program will allow agencies to meet their environmental goals with products that can also meet performance requirements and are cost competitive. (www.biopreferred.gov). Through partnerships with industry, Academia and other Federal agencies, these programs are making a significant contribution to the development and adoption of alternative technologies to increase energy independence and to open new opportunities for agriculture.
Lubricating Oils Evaluation of Dispersancy Capacity of Lubricating Oils and the Impact of Biofuels on Lubricant Dispersancy
Authors: Abellaneda Gerard , Pigeon Didier 
Published: July 2011

Abstract
One of the primary functions of a lubricant is to preserve the cleanliness of a combustion engine’s mechanical parts. The cleanliness of the mechanical parts is facilitated by the introduction of “detergency” and “dispersancy” additives to the engine oil. This last property, dispersancy, is the property that allows the oil to suspend and carry away “pollutants” of diverse sources, such as soot from combustion, metallic particles from wear, corrosion of mechanical parts, and insoluble products resulting from the aging of the oil, etc. Recently, with the arrival of new fuels (e.g., biodiesel, ethanol blends, etc.) we notice that the existing or traditional lubricants present an important variability in terms of durability and resistance to pollutants, such as the fuel or the biofuel. Our studies show that the dispersancy capacity of certain types of lubricants is significantly degraded by the presence of specific pollutants, and in particular fatty acid methyl esters of the biofuels, which have a significant impact. It is therefore important to quantify the degradation of the oil in-service (engines or transmission oils) and to monitor the evolution of the oil’s dispersancy properties during use to be able to determine steps and intervals for maintenance. Additionally, for the development of new lubricants it is necessary to define a criterion of acceptance of the oil by its dispersancy capacity. This new method will define and quantify this criterion. The writers will present the results of these studies with particular emphasis on the impact of biofuels on the dispersancy capacity of both gasoline and diesel engine oils. They will describe a method of analysis using an automated instrument providing precise, objective measurement of this important parameter. This method will therefore be able to estimate the dispersancy capacity of lubricants, as well as the implication of various pollutants on this parameter.