bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the Slip Resistance of Flooring Materials
Authors: James DI 
Published: March 2009

A standard rubber for assessing slip resistance is specified and recommended. This Standard Simulated Shoe Sole (Four S rubber) is available from Rapra Technology Limited. When it is used in the British Portable Pendulum Test it gives increased sensitivity on smooth floors in wet conditions. This rubber is additional to that used for measuring the skid resistance of roads and exterior paved areas.
A new approach to slip resistance measurement is suggested. In a prototype apparatus, it is arranged that the normal load diminishes as a sled is propelled by a constant force. The time taken for the sled to travel a set distance then gives a measure of the slip resistance of the surface. Fractional force and velocity both change during measurement in a manner thought to be similar to the changing parameters in a slipping accident. The measured time is related to the reaction time of the person who slips, making it possible to allow for age, infirmity, or other impairment. A few preliminary results are given, but no comparison with other tests has yet been made.
Fracture Resistance of a Pressure Vessel Steel Under Impact Loading Conditions
Authors: Böhme W 
Published: March 2009

Impact experiments were performed with Charpy specimens and with large bend specimens made from a ferritic pressure vessel steel. All specimens were side-grooved and fatigue-precracked. Different amounts of ductile crack extension up to 16 mm were achieved by varying the available impact energy. The measured hammer load signals were evaluated to calculate J integral values.
The determined dynamic J-resistance curves of the bend specimens are significantly above the Charpy data. Examinations of the fracture surfaces and metallographic sectioning perpendicular to the crack front showed that behind the stretched zone the ductile main crack is accompanied by side cracks with a length up to about 3 mm for the large specimens, whereas such side cracks are hardly found in Charpy specimens. The additional energy needed for the formation of side cracks might explain higher J-resistance curves for larger specimens.
Further results indicate that with increasing loading rate and specimen size the tendency to develop side cracks increases in correlation with higher J-resistance curves. Finally, an attempt is made to discuss the relevance of this effect for the behavior of components.
Dynamic Crack-Tip Opening Displacement (CTOD) Measurements with Application to Fracture Toughness Testing
Authors: Tregoning RL , Shapiro JM , Sharpe WN 
Published: March 2009

Crack-tip opening displacement (CTOD) measurements were made 100 üm behind the crack tip on standard three-point bend specimens using a laser-based interferometric technique. Four materials (SAE-01 steel, 4340 steel, HY-100 steel, and tungsten) were tested at loading rates ranging from quasi-static (K ≈ 1 MPa∙ m½/s) to dynamic (K ≈ 106 MPa ∙ m½/s).The quasi-static and intermediate rate tests and analyses were conducted according to the guidelines specified in ASTM Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399). In these lower rate tests, load was applied by a servohydraulic testing machine and a clip gage was used to record the crack-mouth opening displacement (CMOD). From these data, the stress intensity factor, K, and the fracture toughness can easily be determined from the standard methodology.In the high rate tests, inertial effects are prevalent and K is not as easily measured. The initial measurements of CTOD, however, can be used to provide a calibration between the static and dynamic tests if K is assumed to increase linearly with time during the 10 to 15 μs before the crack starts to propagate. If this assumption holds, dynamic time-CTOD results can be converted to K-CTOD curves using a companion specimen technique. Further, the dynamic fracture toughness can then be found by superimposing static and dynamic K-CTOD results and employing a reduced slope technique to locate the onset of crack propagation.This dynamic technique has been modeled after existing practices defined in ASTM Test E 399 and leads to experimental scatter comparable to that found in static fracture-toughness tests. The results show that there is no dramatic change in the fracture toughness over this range of loading rates for any of the materials studied.
Comparison of In-Situ Resilient Moduli of Aggregate Base Courses With and Without Low Percentages of Lime Stabilization
Authors: Little DN 
Published: March 2009

Six pavement sections were tested using a falling weight deflectometer (FWD). The six pavement sections were all in the Phoenix, AZ area. All six pavements have the same pavement structural cross-section: 3 to 4 in. (76.200–101.60 mm) of hot mix asphalt concrete surface supported by 10 to 13 in. (254.00–330.20 mm) of aggregate base course and underlain by a granular subgrade. Three of the six pavements possess aggregate base courses which have been stabilized with 1 % hydrated lime. The other three pavements incorporate the same aggregate base course but without lime stabilization.
Resilient moduli of all pavement layers were back-calculated based on the FWD data. The moduli of all pavement layers are analyzed statistically. The addition of the same percentage of lime is shown to make a substantial difference in the stiffness of the layers and the structural contribution of the base layer to the pavement system. The effect of the stabilization with small percentages of lime on pavement performance and pavement life is discussed.
Calcium Hydroxide Treatment of Construction Aggregates for Improved Cementation Properties
Authors: Graves RE , Eades JL , Smith LL 
Published: March 2009

Laboratory studies have shown beneficial effects from calcium hydroxide (Ca(OH)2) treatment of crushed aggregate materials commonly utilized in construction. Two contrasting cementation systems were investigated which demonstrate how Ca(OH)2 treatment of aggregates may be effectively used to improve the cementing properties of construction materials.
Highway base course materials composed of crushed limestone aggregates have been observed to increase in strength with time after compaction and is thought to be due to natural carbonate cementation processes. Addition of Ca(OH)2 to crushed limestone base course materials before compaction caused significant increases in laboratory bearing strength values after continuous soaking in water. It is believed this is due to carbonation of the Ca2+ ions, producing additional calcium carbonate cementation of the particles. The amount of strength developed is a function of calcite/quartz ratios for the compacted materials. Scanning electron microscope (SEM) investigations suggest this is due to the better bonding properties of carbonate cement-carbonate particle systems versus carbonate cement-silicate particle systems.
In portland cement concrete, carbonate aggregates appear to react chemically with the cement hydration products, forming a good interfacial bond. In contrast, cracks are often more prominent at the cement paste-silicate aggregate interface, suggesting this is a weak link in both strength and durability of concrete. Treatment of crushed granite aggregates with a Ca(OH)2 solution, followed by the subsequent drying of the aggregates, resulted in increased compressive strength for 28 day moist cured portland cement concrete mixes. SEM studies of concrete prepared with untreated and treated granite aggregates suggest this is due to improved interfacial bonding between the cement paste and treated granite aggregates. The proposed mechanism for improved bonding is disruption of the hydrated silicate surface by drying, allowing for stronger adsorption of Ca2+ ions onto negative charge sites. This appears to provide a bridging mechanism for bonding cement hydration products to the silicate aggregate surface.
Intraoperative Impact: Characterization and Laboratory Simulation on Composite Hip prostheses
Authors: Maharaj GR , Jamison RD 
Published: March 2009

Impact force measurements and energy calculations were performed on five embalmed cadaveric femora and an intact cadaver undergoing composite hip stem insertion using standard surgical methods. In addition, the number of impacts required to fully seat each stem was recorded.
The mean hammer velocity at the instant of impact was 5.15 ± 0.14 m/s and six impacts were required to fully seat the stem in all cases. The mean impact force was 6.20 ± 0.15 kN for the isolated femurs and 5.83 ± 0.67 kN for the cadaver. The mean impact energy was calculated to be 4.50 ± 0.54 J for the isolated femurs and 4.55 ± 0.43 J for the cadaver. Microscopic examination of the stems revealed no evidence of surface damage in any of the tests.
The forces and energies associated with intraoperative impact as measured in this study are sufficiently large to be of concern when considering the introduction of composite materials as replacements for metals in hip femoral components. Impact testing should be woven into the test scheme for both candidate composite materials and for different hip designs using these materials.
A Survey of Practicing Anesthesiologists on Auditory Alarms in the Operating Room
Authors: Griffith RL , Raciot BM 
Published: March 2009

Electronic monitoring equipment appears to have advanced measurably the safety of anesthesia care by extending the human senses of the anesthetist beyond his native sight, touch, smell, and hearing. Yet electronic vigilance of an anesthetized patient is effective only when information receives the attention of the anesthetist for analysis and action. Auditory signaling has been used commonly to alert the anesthetist to unusual measurements made by a monitoring device. While there is general acceptance that auditory signaling or auditory alarms may be suboptimal in the operating room, there may not be sufficient quantification of the acceptability of alarms for rational selection of remedies.
Five hundred anesthesiologists in active practice in the United States of America were selected at random from the directory of the American Society of Anesthesiologists. A letter and a questionnaire were mailed to each anesthesiologist with a stamped envelope to facilitate a reply. The number of responses and the frequency of comments indicates a high degree of interest in the issue of operating room alarms. Alarms appear to be viewed as a contributor to stress in the operating room. Anesthesiologists want their alarms to be clearly different than alarms on other equipment in the operating suite. There appears to be good support for distinctive alarm sounds, graded alarms, and intermittent alarms, although there are differences in opinion on the optimal type of alarm between voice, central displays, or distinctive tones.
Problems in Designing Studies for Pharmaceutical Development: Patients, Prescriptions, and Physicians
Authors: Fishken D 
Published: March 2009

More palatable pharmaceuticals mean easier administration, better compliance with prescription requirements, and less unpleasantness associated with illness. Developing the best possible taste, smell and texture for a pharmaceutical product requires the presence of the active ingredient; its taste or smell has to be masked or mitigated. With an active ingredient present, the respondent must be a “patient,” someone who uses this product when needed.
Some of the factors that determine the research design are: (1) the status of the product, is it “over the counter” (OTC) or prescription, and (2) the need to conduct tests among symptomatic patients versus asymptomatic individuals. In the case of OTC products, research designs must often be submitted to an Institutional Review Board (IRB), so that an independent group of specialists, including a physician, can determine that the project is conducted in an ethical manner. IRBs are required when nonphysicians administer pharmaceuticals. In the case of prescription drugs, physicians must be employed to place products with their patients when illness calls for the particular drug under investigation.
With regard to the presence or absence of symptoms, consider that tests of liquid cold remedies or nasal decongestants require symptomatic individuals since sensory acuities are altered by nasal decongestion. On the other hand, antacid tests do not require the presence of symptoms when the issues are taste and texture.
Case studies are presented to demonstrate the complexities of sensory research for OTC and prescription products.
Impact Factors for Highway Bridges
Authors: GangaRao HVS 
Published: March 2009

This paper deals with the review of impact or dynamic allowance factors for highway bridges that are being implemented by various countries around the world. This review has specifically emphasized the field results of other researchers and concluded that most of the studies have noted that the current American Association of State Highways and Transportation Officials (AASHTO) Specifications grossly underestimate the impact factors for highway bridges. The review of impact factors herein has concluded further that the AASHTO Specifications on impact for highway bridges are a function only on the span length, even though many other important parameters (for example, road roughness, vehicle and bridge dynamics) play a major role in terms of bridge dynamics.
Test results of two medium span steel stringer concrete deck bridges (span length approx. 100 ft.) on West Virginia's highway systems are reported herein for varying truck speeds, and for various bridge natural frequencies, dynamic strains on stringers, concrete slabs, and abutments.
A deterministic procedure, based on the orthotopic plate theory that was developed at West Virginia University, has been used to compute frequencies, deformations and stresses. In addition, I-D beam theory has been used to compute natural frequencies. A comparison of these theoretical results with the experimental is found to be satisfactory.
An Aqueous Fine Clean Process for Rocket Engine Hardware
Authors: Becker JF , Shoemaker MC 
Published: March 2009

An aqueous fine clean process has been developed for large-scale, complex rocket engine hardware required to meet a cleanliness level of less than 10 mg/m2 (&lt;1 mg/ft2) nonvolatile residue (NVR) and no particles greater than 400 μm in any dimension. The hardware must be compatible with oxygen over the parameter range of liquid oxygen at -160°C (-256°F) and 61 MPa (8800 psi) to gaseous oxygen at +704°C (+1300°F) and 31.5 MPa (4570 psi).
The complete cleaning cycle is comprised of a preclean operation, fine clean, and verification. The aqueous fine clean process developed is a two step operation using a nonionic surfactant diluted in deionized water as a prerinse followed by a final rinse of fresh deionized water. A nonionic surfactant was selected to minimize corrosion and to meet current NASA specification requirements.
The cleanliness of hardware surfaces in this study was determined by analyzing the effluent from flushing with ambient temperature 1, 1, 1-trichloroethane (TCA) in a 30 000 Class cleanroom. The particulate matter was determined by filtering the TCA using a 0.45 μm filter and the NVR was determined by gravimetric procedure. Oxygen compatibility was determined by testing in ambient pressure liquid oxygen at -160°C using an impact energy of 10 kg-m.
Realizing Bench Test Solutions to Field Tribology Problems by Utilizing Tribological Aspect Numbers
Authors: Voitik RM 
Published: March 2009

This paper will explore the path from the field wear problem to the bench test solution. The perspective will be from that of the product designer who is experiencing a wear problem in the field. Attention will be given to extracting the necessary key information in the field problem to assist in the subsequent testing steps. A tribological code is developed to facilitate the transition from the field problem to the bench test.
The impact of the selection of contact geometry will be reviewed relative to the various test machines which are available. This is more complex today since there are many test machines and many of the test machines utilize adapters which permits a multitude of test geometries. Many special test variations have been developed over the years and these will be discussed to show the broad spectrum of testing opportunities which exists. Consideration of all the test parameters relative to accelerated tests will be reviewed.
The techniques of initial exploratory tests prior to starting the test program will be reviewed relative to the field problem and the proposed test conditions.
Interpretation of the test results will be explained for several test examples.
Preliminary Assessment of Radiation Control Coatings for Buildings
Authors: Anderson RW , Yarbrough DW , Graves RS , Wendt RL 
Published: March 2009

Radiation Control Coatings (RCCs) applied to external building surfaces can reflect about 85 percent of the solar heating from the surfaces of buildings. Since in warm climates, solar heating is the primary source of heat gain through walls and roofs, RCC technology represents an alternative or adjunct to conventional thermal control methods (e.g. thermal insulation) for opaque building components.
The primary objectives of this project were to: (1) obtain solar and infrared reflectance data for representative RCC products, (2) evaluate test methods for measurement of the radiative properties of RCCs; (3) calculate the changes in heat flow attributed to RCCs in flat roof applications in several geographic locations; and (4) compare field tests and calculated thermal performance of an RCC in a flat roof configuration.
Data are presented for the reflectance properties of five commercially available RCC products as determined by several test methods. The potential energy benefits of RCCs are presented for flat roofs in both warm and cold climates.
Energy Code Measures to Assure the Effectiveness of Thermal Insulation Installed in Buildings
Authors: Nelson BD 
Published: March 2009

Several common residential construction details are detrimental to the performance of installed thermal insulation. Degradation of insulation performance is caused by air exfiltration (convective losses and moisture gain in insulated cavities) and wind wash (the passage of outdoor air through insulation).
Existing model energy codes in the United States address the exfiltration issue, although enforcement appears to be only partially effective. U.S. model energy codes do not address wind wash. New provisions of the Minnesota Energy Code for residential buildings are intended to require construction details that would reduce exfiltration and wind wash. The language addressing these construction details is generally more prescriptive than in existing model energy codes.
The inclusion of language in residential energy codes to improve the performance of thermal insulation follows the lead of special programs' building standards for energy efficient construction.
Moisture Diffusion in Thermal Insulating Materials
Authors: Freitas V , Crausse P , Abrantes V 
Published: March 2009

The moisture behaviour of building materials, especially the kinetics of wetting and drying, is very important because it can influence the hygrothermal performance of the building envelope and the internal comfort.
The mathematical model of heat and mass transfer, in porous media, proposed by LUIKOV — PHILIP and DE VRIES shows that moisture migration, in isothermal conditions, is a function of the humidity gradient and the moisture diffusivity coefficient. This paper reports values of moisture diffusivity coefficients for some thermal insulating materials and how these are calculated. The results of numerical simulation of drying of these materials and a comparison with the data obtained from measurements using gamma-ray spectroscopy in the determination of the moisture distribution are also presented.
A Round-Robin Comparison of Australasian Thermal Laboratories
Authors: Trethowen HA , Desjarlais AO 
Published: March 2009

This paper describes a comparison of seven laboratories in Australia and New Zealand, and one US laboratory, involved in testing thermal properties of materials. The primary objective of this Round Robin was to establish or confirm what degree of confidence can be placed in measurements by the various laboratories in this region. It was carried out using two industrial insulant products which were premeasured. Three samples were sent to each participant, who each conducted four thermal resistance measurements.
Results were typically within ±6% of the mean value, with a worst-case difference of -15.5% from the mean value.
ASTM/DOE Hot Box Round Robin
Authors: Bales E 
Published: March 2009

This paper presents the results of inviting the operators of all guarded and calibrated hot boxes in North America to participate in a round robin, an interlaboratory test program according to ASTM E 691, “Conducting an Interlaboratory Test Program to Determine the Precision of a Test Method”, to establish the precision and bias of the corresponding ASTM standard test methods: ASTM C 236, “Steady-State Thermal Performance of Building Assemblies by Means of a Guarded Hot Box”, and C 976, “Thermal Performance of Building Assemblies by Means of a Calibrated Hot Box”. The data and data analysis are reported from twenty-one laboratories that completed a series of tests on 4-inch thick specimens of cellular polystyrene thermal insulation. The data analysis resulted in two recommended statements of precision and bias.
Ninety-five per cent of the time measurements from two different laboratories on the same specimen would differ by up to +/-7.8% at a mean temperature of 75 F for the guarded hot box, and by up to +/-5.6% for the calibrated hot box. Based on guarded hot plate data for the specimen material, the reference value is 15.9 hr-F-ft sq/Btu. The mean of the thermal resistance reported for guarded hot boxes was 15.77 hr-F-ft sq/Btu, which differs by -1.2% from the reference value. The mean of the thermal resistance reported for calibrated hot boxes was 16.32 hr-F-ft sq/Btu, which differs by +2.6% from the reference value.