Standard Test Series Research Articles

Characterization of gypsum plasterboard with polyurethane foam waste reinforced with polypropylene fibers

Gypsum plasterboard that incorporates various combinations of polyurethane foam waste and polypropylene fibers in its matrix is studied. The prefabricated material was characterized in a series of standardized tests: bulk density, maximum breaking load under flexion stress, total water absorption, surface hardness, thermal properties, and reaction to fire performance. Polypropylene fibers were added to the polyurethane gypsum composites to improve the mechanical behavior of the plasterboard under loading. The results indicate that increased quantities of polymer waste led to significant reductions in the weight/surface ratio, the mechanical strength and the surface hardness of the gypsum, as well as improving its thermal resistance. The polypropylene fibers showed good adhesion to the polymer and the gypsum matrix, which enhanced the mechanical performance and the absorption capacity of these compounds. The non-combustibility test demonstrated the potential of the new material for use in internal linings.

Elastically-homogeneous lattice models of damage in geomaterials

This study involves the development of the auxiliary stress approach for producing elastically-homogeneous lattice models of damage in geomaterials. The lattice models are based on random, three-dimensional assemblages of rigid-body-spring elements. Unlike conventional lattice or particle models, the elastic constants of a material (e.g., Young’s modulus and Poisson’s ratio) are represented properly in both global and local senses, without any need for calibration. The proposed approach is demonstrated and validated through analyses of homogeneous and heterogeneous systems under uni- and tri-axial loading conditions. Comparisons are made with analytical solutions and finite element results. Thereafter, the model is used to simulate a series of standard laboratory tests: (a) split-cylinder tests, and (b) uniaxial compressive tests of sedimentary rocks at the Horonobe Underground Research Laboratory in Hokkaido, Japan. Model inputs are based on physical quantities measured in the experiments. The simulation results agree well with the experimental results in terms of pre-peak stress-strain/displacement responses, strength measurements, and failure patterns.

Filament Wound Composite Pressure Vessels and Pipes Subject to an Internal Pressure: An Experimental and Material Characterization Study

This study presents an experimental testing regime conducted on filament wound composite pressure vessels (CPVs) made up of an asymmetric and unbalanced layup (chopped strand mat (CSM)/−82.7 deg/±54.3 deg) and subject to an internal pressure. Polyester reinforced with e-glass CSM and direct roving was used. The mechanical properties of the different lamina used in the test specimens were identified through a series of standardized tests. The evolution of strain and volume changes with respect to the applied pressure loading were recorded. The results also present a characterization of identifiable first-ply failure (FPF) loads based on strain evolution and volume changes, and monitors when ultimate failure occurs.

An efficient exponential time integration method for the numerical solution of the shallow water equations on the sphere

The exponential propagation methods were applied in the past for accurate integration of the shallow water equations on the sphere. Despite obvious advantages related to the exact solution of the linear part of the system, their use for the solution of practical problems in geophysics has been limited because efficiency of the traditional algorithm for evaluating the exponential of Jacobian matrix is inadequate. In order to circumvent this limitation, we modify the existing scheme by using the Incomplete Orthogonalization Method instead of the Arnoldi iteration. We also propose a simple strategy to determine the initial size of the Krylov space using information from previous time instants. This strategy is ideally suited for the integration of fluid equations where the structure of the system Jacobian does not change rapidly between the subsequent time steps. A series of standard numerical tests performed with the shallow water model on a geodesic icosahedral grid shows that the new scheme achieves efficiency comparable to the semi-implicit methods. This fact, combined with the accuracy and the mass conservation of the exponential propagation scheme, makes the presented method a good candidate for solving many practical problems, including numerical weather prediction.

Comparison of Terrain-Following and Cut-Cell Grids Using a Nonhydrostatic Model

Abstract Terrain-following coordinates are widely used in operational models but the cut-cell method has been proposed as an alternative that can more accurately represent atmospheric dynamics over steep orography. Because the type of grid is usually chosen during model implementation, it becomes necessary to use different models to compare the accuracy of different grids. In contrast, here a C-grid finite-volume model enables a like-for-like comparison of terrain-following and cut-cell grids. A series of standard two-dimensional tests using idealized terrain are performed: tracer advection in a prescribed horizontal velocity field, a test starting from resting initial conditions, and orographically induced gravity waves described by nonhydrostatic dynamics. In addition, three new tests are formulated: a more challenging resting atmosphere case, and two new advection tests having a velocity field that is everywhere tangential to the terrain-following coordinate surfaces. These new tests present a challenge on cut-cell grids. The results of the advection tests demonstrate that accuracy depends primarily upon alignment of the flow with the grid rather than grid orthogonality. A resting atmosphere is well maintained on all grids. In the gravity waves test, results on all grids are in good agreement with existing results from the literature, although terrain-following velocity fields lead to errors on cut-cell grids. Because of semi-implicit time stepping and an upwind-biased, explicit advection scheme, there are no time step restrictions associated with small cut cells. In contradiction to other studies, no significant advantages of cut cells or smoothed coordinates are found.

The Revised Neurobehavioral Severity Scale (NSS-R) for Rodents.

Motor and sensory deficits are common following traumatic brain injury (TBI). Although rodent models provide valuable insight into the biological and functional outcomes of TBI, the success of translational research is critically dependent upon proper selection of sensitive, reliable, and reproducible assessments. Published literature includes various observational scales designed to evaluate post-injury functionality; however, the heterogeneity in TBI location, severity, and symptomology can complicate behavioral assessments. The importance of choosing behavioral outcomes that can be reliably and objectively quantified in an efficient manner is becoming increasingly important. The Revised Neurobehavioral Severity Scale (NSS-R) is a continuous series of specific, sensitive, and standardized observational tests that evaluate balance, motor coordination, and sensorimotor reflexes in rodents. The tasks follow a specific order designed to minimize interference: balance, landing, tail raise, dragging, righting reflex, ear reflex, eye reflex, sound reflex, tail pinch, and hindpaw pinch. The NSS-R has proven to be a reliable method differentiating brain-injured rodents from non-brain-injured rodents across many brain injury models.

온도에 따른 사질토의 다짐 특성

Abstract Among several factors controlling soil compaction, temperature is the factor that varies with region and season. Although earthwork is performed in many projects in the cold regions of the earth, studies on quantifying soil compaction associated with temperature are limited. This experimental study investigates the temperature effect on the soil compaction of cohesionless soil. Jumunjin sand was selected for the tests to represent cohesionless clean sand, which is widely used as an engineering fill at petrochemical projects such as northern Alberta of Canada and Russia. The laboratory test program consists of performing a series of standard proctor tests varying temperature of soil samples ranging from -10°C to 17°C. Test results indicate that soil specimen volume expansion occurred from bulking and its range was 0% to 6% with zero above temperature. For increasing temperature from 0°C to 17°C, water content corresponding to maximum volume (minimum dry unit weight) was decreased and water content corresponding to minimum volume (maximum dry unit weight observed after reaching minimum dry unit weight) was slightly increased with increasing temperature. In zero below temperature, dry unit weight gradually decreased with increasing water content. In this case, no bulking effect was found and soil specimen volume increased due to the higher unit volume of ice.

A NEW MULTI-ENERGY NEUTRINO RADIATION-HYDRODYNAMICS CODE IN FULL GENERAL RELATIVITY AND ITS APPLICATION TO THE GRAVITATIONAL COLLAPSE OF MASSIVE STARS

ABSTRACT We present a new multi-dimensional radiation-hydrodynamics code for massive stellar core-collapse in full general relativity (GR). Employing an M1 analytical closure scheme, we solve spectral neutrino transport of the radiation energy and momentum based on a truncated moment formalism. Regarding neutrino opacities, we take into account a baseline set in state-of-the-art simulations, in which inelastic neutrino–electron scattering, thermal neutrino production via pair annihilation, and nucleon–nucleon bremsstrahlung are included. While the Einstein field equations and the spatial advection terms in the radiation-hydrodynamics equations are evolved explicitly, the source terms due to neutrino–matter interactions and energy shift in the radiation moment equations are integrated implicitly by an iteration method. To verify our code, we first perform a series of standard radiation tests with analytical solutions that include the check of gravitational redshift and Doppler shift. A good agreement in these tests supports the reliability of the GR multi-energy neutrino transport scheme. We then conduct several test simulations of core-collapse, bounce, and shock stall of a 15 M ⊙ ?> star in the Cartesian coordinates and make a detailed comparison with published results. Our code performs quite well to reproduce the results of full Boltzmann neutrino transport especially before bounce. In the postbounce phase, our code basically performs well, however, there are several differences that are most likely to come from the insufficient spatial resolution in our current 3D-GR models. For clarifying the resolution dependence and extending the code comparison in the late postbounce phase, we discuss that next-generation Exaflops class supercomputers are needed at least.

Application of Recursive Subspace Method in Vehicle Lateral Dynamics Model Identification

Modeling of vehicle behavior based on the identification method has received a renewed attention in recent years. In order to improve the linear time-invariant vehicle identification model, a more general identifiable vehicle model structure is proposed, in which time-varying characteristics of vehicle speed and cornering stiffness are taken into consideration. To identify the proposed linear time-varying vehicle model, a well-established data-driven method, named recursive optimized version of predictor-based subspace identification, is introduced. Before vehicle model identification, the influences of four parameters in the subspace algorithm are studied based on pulse input road test. And then a set of practical optimal parameters are chosen and used for the vehicle model identification. Through a series of standard road tests under different maneuvers, the linear time-varying vehicle model can be identified in real-time. It is demonstrated by comparison that the predicted outputs of the proposed vehicle model are much closer to the real vehicle outputs and the model has a wider range of application.

Ensayos a mezclas de barro estabilizadas para el relleno y empañetado de paredes de Bahareque

The buildings of bahareque deteriorate mostly due to the vulnerability of the mud to moisture and the use of not adequate mixtures in its repairs. In order to improve the mud mixtures of the filling and mud cover of bahareque walls, was carried out a research whose results are presented in this article. This research studied the behavior of mud mixtures stabilized with cement and/or lime, to the effects of water. For this purpose a series of standardized tests were performed and it was designed a customized absorption test for the proposed stabilized mud mixtures. Mud mixtures with 10% of additives for the filling, and up to 15% of additives for the mud cover were proposed. In the mixtures was also added debris of clay or cement blocks to replace the stones that are usually used in the bahareque of the Zulia state, Venezuela. Due to the uniformity in the results of the mixtures with cement and lime additives, it is concluded that any of the proposed mixtures can be used in a rehabilitation of bahareque walls, but it is recommended the mud mixture with 10 percent of cement and clay blocks, because it had the lowest values of water absorption, that is to say, it is the most waterproof.

Adaptive learning method for multiple-object detection in manufacturing

In manufacturing, vision-based inspections are effective nondestructive methods for implementing object discrimination. To minimize inspection times, multiple-object discrimination must be implemented for one inspection image. However, multiple-object inspections are difficult to perform in manufacturing because of the lack of distinct objects in inspection images. In addition, inspectors might fail to use multiple sensing devices when concurrently detecting objects. This article proposes a novel multiple-object sensing system that incorporates a local-adaptive-region-growing–based learning method for adaptively segmenting multiple-camera images for multiple-object discrimination. The proposed local-adaptive-region-growing method and support vector machine-based discrete wavelet transform can effectively classify multiple objects in the local subregions of inspection images. The proposed system bridges the gap between sensing devices and inspectors for solving problems encountered when concurrently using multiple sensing devices. The learning method yielded more favorable results than existing inspection methods have. Furthermore, a standard test series was developed for quantitatively comparing inspection methods.

Uptake and toxicity of methylmethacrylate-based nanoplastic particles in aquatic organisms.

The uptake and toxicity of 2 poly(methylmethacrylate)-based plastic nanoparticles (PNPs) with different surface chemistries (medium and hydrophobic) were assessed using aquatic organisms selected for their relevance based on the environmental behavior of the PNPs. Pure poly(methylmethacrylate) (medium; PMMA PNPs) and poly(methylmethacrylate-co-stearylmethacrylate) copolymer (hydrophobic; PMMA-PSMA PNPs) of 86 nm to 125 nm were synthesized using a miniemulsion polymerization method. Fluorescent analogs of each PNP were also synthesized using monomer 7-[4-(trifluoromethyl)coumarin]acrylamide and studied. Daphnia magna, Corophium volutator, and Vibrio fischeri were employed in a series of standard acute ecotoxicity tests, being exposed to the PNPs at 3 different environmentally realistic concentrations (0.01 mg/L, 0.1 mg/L, and 1.0 mg/L) and a high concentration 500 mg/L to 1000 mg/L. In addition, sublethal effects of PNPs in C. volutator were determined using a sediment reburial test, and the uptake and depuration of fluorescent PNPs was studied in D. magna. The PNPs and fluorescent PNPs did not exhibit any observable toxicity at concentrations up to 500 mg/L to 1000 mg/L in any of the tests except for PMMA-PSMA PNPs and fluorescent PNPs following 48-h exposure to D. magna (median lethal concentration values of 879 mg/L and 887 mg/L, respectively). No significant differences were observed between labeled and nonlabeled PNPs, indicating the suitability of using fluorescent labeling. Significant uptake and rapid excretion of the fluorescent PNPs was observed in D. magna. Environ Toxicol Chem 2016;35:1641-1649. © 2015 SETAC.

Validity study of Animal-City Alternating Form Fluency Test in the identification of mild cognitive impairment and Alzheimer's disease

Objective To identify the sensitivity and specificity of Animal-City Alternating Form Fluency Test (ACFT) differentiating mild cognitive impairment (MCI) and Alzheimer's disease (AD) from normal controls. Methods A total of 121 MCI patients, 104 AD patients and 104 healthy controls, who were matched in sex, age and education level, were enrolled in this study. They performed Animal Category Verbal Fluency Test (AFT), City Category Verbal Fluency Test (CFT) and ACFT. A series of standard neuropsychological tests were also administered to reflect episodic memory, verbal ability, working memory, executive function and processing speed. The validity and related influencing factors of ACFT was evaluated. Results Compared with control group, the ACFT correct number in MCI and AD groups reduced significantly ( P = 0.000, 0.000). Receiver operating characteristic (ROC) curve revealed the sensitivity and specificity of ACFT in discriminating MCI ( P = 0.012, 0.030) and AD ( P = 0.004, 0.003) from normal controls were higher than those of AFT and CFT. There was no correlation of correct number in ACFT with age and education ( P > 0.05, for all). The correlations of ACFT with Stroop Color-Word Test (SCWT), Digital Symbol Substitution Test (DSST), Shape Trail Test (STT) and Digit Span Test (DS), all of which reflected attention and executive function, were significantly closer than those of AFT and CFT ( P < 0.05, for all). Conclusions ACFT is more efficient in early cognitive impairment identification than the other traditional category verbal fluency tests. It is a new variant form of category verbal fluency test that could assess cognitive function and could be broadly applied in clinical practice. DOI: 10.3969/j.issn.1672-6731.2015.07.010

Performance assessment of two whole-lake acoustic positional telemetry systems--is reality mining of free-ranging aquatic animals technologically possible?

Acoustic positional telemetry systems (APTs) represent a novel approach to study the behaviour of free ranging aquatic animals in the wild at unprecedented detail. System manufactures promise remarkably high temporal and spatial resolution. However, the performance of APTs has rarely been rigorously tested at the level of entire ecosystems. Moreover, the effect of habitat structure on system performance has only been poorly documented. Two APTs were deployed to cover two small lakes and a series of standardized stationary tests were conducted to assess system performance. Furthermore, a number of tow tests were conducted to simulate moving fish. Based on these data, we quantified system performance in terms of data yield, accuracy and precision as a function of structural complexity in relation to vegetation. Mean data yield of the two systems was 40 % (Lake1) and 60 % (Lake2). Average system accuracy (acc) and precision (prec) were Lake1: acc = 3.1 m, prec = 1.1 m; Lake2: acc = 1.0 m, prec = 0.2 m. System performance was negatively affected by structural complexity, i.e., open water habitats yielded far better performance than structurally complex vegetated habitats. Post-processing greatly improved data quality, and sub-meter accuracy and precision were, on average, regularly achieved in Lake2 but remained the exception in the larger and structurally more complex Lake1. Moving transmitters were tracked well by both systems. Whereas overestimation of moved distance is inevitable for stationary transmitters due to accumulation of small tracking errors, moving transmitters can result in both over- and underestimation of distances depending on circumstances. Both deployed APTs were capable of providing high resolution positional data at the scale of entire lakes and are suitable systems to mine the reality of free ranging fish in their natural environment. This opens important opportunities to advance several fields of study such as movement ecology and animal social networks in the wild. It is recommended that thorough performance tests are conducted in any study utilizing APTs. The APTs tested here appear best suited for studies in structurally simple ecosystems or for studying pelagic species. In such situations, the data quality provided by the APTs is exceptionally high.

Regulatory biocompatibility requirements for biomaterials used in regenerative medicine.

The biological safety of biomaterials used for implantable medical devices is usually determined by a series of standard tests that assess the effects that extractable substances have on cells in vitro and in simple short term animal studies. To use these tests to determine the suitability of materials for tissue engineering templates is inappropriate. This short essay discusses the issues that are involved.

Occupational contact dermatitis due to captopril

This article was originally published online on 8 April 2015 Approximately 50% of adverse drug reactions to angiotensin-converting enzyme (ACE) inhibitors occur in the skin. While angioedema is a well-known adverse cutaneous reaction to ACE inhibitors, other skin reactions are uncommon. We report the case of a patient with occupational contact dermatitis due to skin contact of the ACE inhibitor captopril. Literature review and case description. We assessed a 36 years old female with a history of palpebral and lips oedema, flaking and pruritus, for two months, especially during her work. She worked in pharmaceutical industry and was referred to our outpatient because she had noticed worsening after contact with residues contained in captopril packaging during its manipulation. She had improved when had no contact with the packages. She was treated with topical corticosteroids and oral antihistamines. We performed contact delayed reading test (patch test) with captopril in the concentration of 10%, resulting papules, vesicles and swelling at the application site. In addition, there was a negative reaction standard test series. We told her to avoid new exposures to this drug and others with cross reaction. Adverse skin reactions to anti-hypersensitive drugs are not uncommon, eczema and rashes usually being caused by thiazides, amiloride or beta-blocking drugs. It is well known that ACE inhibitors elicit angioedema. However, there have been few reports of eczematous skin reactions to ACE inhibitors and all have been due to captopril intake. We reported a patient having occupational contact dermatitis to captopril through skin contact. Although an uncommon event, captopril may elicit eczematous allergic reactions which can be diagnosed by patch-testing.

Identification of Linear Tire Cornering Stiffness Using Subspace Methods

In this paper, subspace identification methods are proposed to estimate the linear tire cornering stiffness, which are only based on the road tests data without any prior knowledge. This kind of data-driven method has strong robustness. In order to validate the feasibility and effectiveness of the algorithms, a series of standard road tests are carried out. Comparing with different subspace algorithms used in road tests, it can be concluded that the front tire cornering stiffness can be estimated accurately by the N4SID and CCA methods when the double lane change test data are taken into analysis.

Use of Soil-Rock Mixtures in Dam Construction

AbstractThe employment of nontraditional materials such as soil-rock mixtures, for economic and environmental reasons, in the construction of earthworks poses some new challenges for compaction techniques and their control, and for the determination of the embankment characteristics that result from the compaction method. Those characteristics experience important changes according to the relative percentages of the existing fractions. Usually, this kind of material results from bulky rock extraction without explosives, and it can include some large-size particles (greater than 0.5 m). In addition, the measured deformations associated with these materials have been larger than expected. For the execution control of the soil-rock mixtures from the Odelouca dam borrow areas, a series of vibratory and standard compaction tests was performed to estimate reference values for the maximum dry density and optimum water content of these materials, and a new methodology was proposed. The Odelouca dam is a zoned emb...

A bond contact model for methane hydrate-bearing sediments with interparticle cementation

While methane hydrates (MHs) can be present in various forms in deep seabeds or permafrost regions, this paper deals with MH-bearing sediments (MHBS) where the MH has formed bonds between sand grains. A bond model based on experimentally validated contact laws for cemented granules is introduced to describe the mechanical behavior of the MH bonds. The model parameters were derived from measured values of temperature, water pressure and MH density. Bond width and thickness adopted for each bond of the MHBS were selected based on the degree of MH saturation. The model was implemented into a 2D distinct element method code. A series of numerical biaxial standard compression tests were carried out for various degrees of MH saturation. A comparison with available experimental data shows that the model can effectively capture the essential features of the mechanical behavior of MHBS for a wide range of levels of hydrate saturation under drained and undrained conditions. In addition, the analyses presented here shed light on the following: (1) the relationship between level of cementation and debonding mechanisms taking place at the microscopic level and the observed macro-mechanical behavior of MHBS and (2) the relationship between spatial distribution of bond breakages and contact force chains with the observed strength, dilatancy and deformability of the samples. Copyright © 2014 John Wiley & Sons, Ltd.

Development and Validation of the Breakthrough Pain Assessment Tool (BAT) in Cancer Patients

ContextThe successful management of breakthrough pain depends on a combination of adequate assessment, appropriate (individualized) treatment, and adequate re-assessment. Currently, there is no fully validated clinical assessment tool for breakthrough pain in cancer patients. ObjectivesThe aim of this project was to develop and validate a breakthrough pain assessment tool (the BAT) for use in the clinical setting. MethodsThe content of the BAT was determined by reviewing the medical literature, conducting a Delphi process with experts in breakthrough pain and/or pain assessment and conducting semi-structured interviews with cancer patients with breakthrough pain. The tool was then subjected to a series of standard psychometric tests to assess its factor structure, validity (i.e., content validity, construct validity), reliability (i.e., internal consistency, test-retest reliability), and responsiveness to change. ResultsThe BAT comprised two pages with 14 questions. Factor analysis confirmed the presence of two underlying factors. Psychometric testing confirmed that the tool is valid, reliable, and responsive to change. ConclusionThis study provides initial evidence for the validity and reliability of the breakthrough pain assessment tool which may be used to facilitate the management of patients with breakthrough cancer pain in the clinical setting.