bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating Airbag Safety Vests for Equestrian Sports
Authors: Ade N. , Stämpfli R. , Schmitt K. -U.
Published: December 2015

Thoracic injuries are common in equestrian sports. Advanced safety equipment, including airbag vests, have been introduced to the market to protect this body region. Standard EN13158 [“Protective Clothing—Protective Jackets, Body and Shoulder Protectors for Equestrian Use: For Horse Riders and Those Working with Horses, and for Horse Drivers—Requirements and Test Methods,” European Committee for Standardization, Brussels, 2009 (in German)] defines the minimum requirements for conventional safety vests; however, there is currently no standard related to airbag vests for equestrian sports. The aim of this study is to investigate the applicability of a draft motorcycling standard [prEN1621-4, “Motorcyclists' Protective Clothing Against Mechanical Impact. Part 4: Motorcyclists' Inflatable Protectors—Requirements and Test Methods,” Deutsches Institut für Normung e.V., Berlin, 2010 (in German)] for equestrian airbag vests. Based on EN13158 and prEN1621-4, airbag vests for equestrian sports were tested. In addition to the tests outlined in the above standards, the pressure induced by the inflating airbag on the thorax was measured and the sound level of the deploying airbag was recorded. The use of airbag vests in conjunction with conventional vests was also investigated. Testing airbag vests in accordance with the existing standards was possible without practical issues. The impact tests indicated that airbag vests were able to absorb higher forces compared to conventional vests. The airbag inflation times were recorded to be between 186 and 260 ms. Trigger forces were measured to be between 150 and 593 N. The maximum pressure on the upper body resulted in 20 to 84 kPa. The bang associated with airbag deployment generated a sound level of 87.3 to 98.4 dB(A). The degree of protection offered by airbag vests was demonstrated by applying the procedures prescribed in existing standards. The draft standard for motorcycling proved to be applicable to equestrian sports. However, regarding the interpretation of the test results, it seems necessary to adapt several threshold values of this standard to account for equestrian-specific parameters.
Test Method to Assess Membrane Layer Fatigue Response on Orthotropic Steel Bridge Decks
Authors: Liu X. , Tzimiris G. , Li J. , Scarpas A.
Published: December 2015

In order to adequately characterize the fatigue response of the various membranes with surrounding multilayer surfacing layers on orthotropic steel decks and collect the necessary parameters for FE modeling, the details of the cyclic membrane adhesion tester (MAT) were introduced. The fatigue damage in membrane interface was related to the amount of dissipated work computed by using the measurement of actuator load and piston deformation during the loading cycle. The dissipated work, which is equivalent to the lost part of the total potential energy of the membrane, was utilized to explain the incremental damage during the testing. Furthermore, using the experimental data obtained from MAT, ranking of the bonding characteristics of various membrane products was demonstrated as well as the role of other influencing factors, such as the types of substrate and test temperatures.
Variable Limits and Control Charts Based on the Half Normal Distribution
Authors: Srinivasa Rao B. , Srinivasa Kumar C. , Rosaiah K.
Published: December 2015

The well-known variable control charts for mean and range of sub-groups for the half normal distribution were constructed by three different approaches. One from the first principles of using percentiles of the sampling distribution of the sample mean and sample range, the second from Shewhart control limits, and the third approach was a skewness correction procedure depending on the skewness coefficient. The coverage probabilities of the three different approaches were computed through simulation and compared.
High Spatial Resolution EDS Mapping of Nanoparticles at Low Accelerating Voltage
Authors: Liu Z. W. , Sun C. , Gauvin R. , Wu W. , Zeng Y. , Demers H.
Published: December 2015

In conventional energy-dispersive spectroscopy/scanning-electron microscopy (EDS/SEM) analysis, the pear-shaped interaction volume of incident electrons in the bulk sample determines spatial resolution and the actual scope of EDS analysis is usually a few cubic microns. Lowering the accelerating voltage can reduce effectively the interaction volume of the electron beam. In this study, Monte Carlo (MC) simulation was used to analyze effectively the actual interaction between low-energy incident electrons and nanoparticles. MC x ray, a new Monte Carlo program, was used to further simulate EDS mapping of Ni nanoparticles on the top of an Al2O3 matrix at an accelerating voltage of 3 kV, and the theoretical spatial resolution was calculated to be approximately 10 nm. In addition, EDS mapping images of 17-nm Ni nanoparticles were successfully acquired at high spatial resolution similar to the theoretical value by adjusting the operating conditions for SEM-EDS analysis, including the use of immersion objective lens, the removal of electron trap and collimator, and the reduction of working distance as well as detector distance.
Online Measurement of Alcohol Concentration Based on Radio-Frequency Identification
Authors: Yu Yinshan , Yu Xiaolei , Zhao Zhimin , Liu Jialing , Wang Donghua
Published: December 2015

This paper presents a method for online measuring signal backscattering and reading distance from radio frequency identification (RFID) tags attached to the surface of the liquid, and for calculating the corresponding alcohol concentration. We derive a theoretical formula on the reading distance and received power. Subsequently, the former measurement values are converted to the corresponding alcohol concentration. Experiments are performed using an ISO/IEC 18046-based measurement system in the ultra high frequency (UHF) RFID band [ISO/IEC 18046, “Information Technology—Radio Frequency Identification Device Performance Test Methods,” International Organization for Standardization, London, 2007]. A fitted model of the relationship of alcohol concentration, reading distances, and received power is established. Based on the proposed fitted model, the processor can calculate alcohol concentration in aqueous solutions. The experimental data are compliant to the theoretical counterparts. This online method could be applied to dynamic measurement in automatic assembly line and has the advantages of excellent versatility, high measuring accuracy, stable performance, and quick response speed.
Assessment of Surface Quality of Stone Treated by Water Jet and Bush Hammering Using Geostatistical Simulations
Authors: Ozcelik Y. , Tercan A. E. , Yilmazkaya E.
Published: December 2015

A number of surface-treatment methods can be used to increase the rock roughness to improve its antislip properties while preserving aesthetic appearance. Bush hammering and water jetting are two of these surface-treatment methods. In this study, Sardinian basalt samples were treated with plain water jet and soft and hard bush-hammering methods, and quality of surfaces treated was assessed geostatistically. Realizations of the treated surfaces were generated by using sequential Gaussian simulation. The results show that the surfaces treated by the water-jet method are more homogeneous than others.
Correlation of Global Quantities for Material Characterization by Sharp Indentation Testing of Elastoplastic Materials
Authors: Larsson Per-Lennart
Published: December 2015

Indentation problems pertinent to sharp indenters were examined. The analysis concerned classical elastic-plastic materials and, especially so, the details of the behavior of global contact quantities, such as mean contact pressure and the size of the contact area, in the transition region where elastic and plastic effects are of equal magnitude. The global contact quantities were correlated accurately using a single parameter, comprising both geometrical and mechanical properties, and presented using closed form expressions directly applicable to material characterization or measurements of residual mechanical fields by sharp indentation tests, but also for situations such as contact in gears or in electronic devices. The derived relations were based on highly accurate previous results from finite element studies of sharp indentation problems.
A Novel General Approach for Solving a Supplier Selection Problem
Authors: Chang Kuei-Hu , Chain Kai , Wen Ta-Chun , Yang Gino K.
Published: December 2015

Due to the progress of information technology and the era of globalization, supply chain management (SCM) is now the key activity to obtaining and maintaining the competitive advantage of firms in the global competitive environment. In order to maximize total supply chain profitability, supplier selection plays a very important role in supply chain management. However, the supplier selection process is a complex multiple-criteria decision making (MCDM) problem where both qualitative and quantitative aspects need to be considered. Moreover, there are many unknown, partly known, missing, or inexistent data in the process of collecting data from the supplier selection, increasing the difficulty of supplier selection. It cannot be fully solved by the traditional analytical hierarchy process (AHP) method. Therefore, this study integrated the AHP and the soft set approach for solving the supplier selection problem. The advantage of this proposed method in research is that it has not lost any expertise in providing useful information. A numerical example of the application was also presented. This study compared the results with the traditional AHP method for dealing with incomplete data. The results of the comparison showed that the approaches presented in this paper are preferable in terms of reflecting practical feasibility.
Comparing Raindrop Size and Velocity Measurement Accuracy Using Shadowgraphy, Disdrometery, and Pie Pan Measurement Techniques
Authors: Tullis Blake P.
Published: December 2015

Local raindrop size and velocity data measurements are often used to quantify hyetographs for rainfall events; the accuracy of the rainfall hyetograph is dependent on the accuracy of the raindrop size and velocity measurement technique. Different raindrop size and velocity measurement techniques were evaluated using simulated raindrops of relatively uniform size in the laboratory. The measurement techniques included a high-speed photography-based imaging system (shadowgraphy), an optical disdrometer, and a pie pan method (raindrop size only). The shadowgraphy system, which had a measurement uncertainty of 2.86 %, served as the comparative standard for the other measurement techniques. The disdrometer raindrop size measurements were relatively accurate except for raindrops passing near the lateral limits of the measurement sheet; the peripheral raindrops sizes were estimated to be 97 % smaller than their actual size. The pie pan method overestimated raindrop sizes by approximately 41 %. The disdrometer raindrop velocity data underestimated actual velocities. Of the techniques evaluated, the disdrometer represents the only practical field deployable method for quantifying rainfall data.
Simulation of the Quasi-Static Uniaxial Compressive Behavior of Entangled Titanium Wire Materials (ETWMs)
Authors: Liu Ping , Qiao Yongmin , Zhao Qinghua , Wu Minchang , Li Jipeng
Published: December 2015

A method combining the Voronoi random model with ABAQUS finite element software was employed to simulate the deformation process of entangled titanium wire materials with different porosities under the quasi-static uniaxial compression load, and investigate the deformation mechanism of the materials. The results revealed that the non-uniform density distribution could cause the local deformation and the formation of deformation regions. The model almost did not appear as macroscopic fracture until the final failure. The entangled titanium wire materials models showed typical elastic-plastic behavior under compression load (i.e., three stages of deformation): an elastic stage, a relatively longer plastic collapse platform stage, and a densification stage. It was also found that the “platform stage” in the stress-strain curve during the compression process was not very flat. The length of the platform stage became shorter as porosity decreased, and the plateau compression force increased significantly with the decrease of porosity. These results agreed with the actual compression test results of the entangled titanium wire materials.
A New Family of Quadratic Hazard Rate-Geometric Distributions With Reliability Applications
Authors: Okasha Hassan M. , Kayid M. , Abouammoh M. A. , Elbatal I.
Published: December 2015

This paper introduced the generalized quadratic hazard rate distribution. This new distribution generalizes several well-known distributions such as generalized exponential, generalized Rayleigh, and generalized linear hazard rate. Some statistical and reliability properties of the new distribution were discussed. The maximum likelihood estimates of its unknown parameters were obtained by simulation. The proposed model and other derived results were utilized for fitting real data set and it was shown that the new distribution provided a better fit than some other known distributions.
Evaluation and Comparison of Double Clip Gauge Method and Delta 5 Method for CTOD Measurement in SE(T) Specimens
Authors: Van Minnebruggen Koen , Verstraete Matthias , Hertelé Stijn , De Waele Wim
Published: December 2015

The experimental evaluation of the fracture toughness of line pipe steels and girth welds is increasingly performed through single edge notched tensile—SE(T)—testing. The notch constraint in these specimens closely matches that in pipes. This paper focused on the measurement of the crack tip opening displacement (CTOD). The double clip gauge method and the GKSS δ5 method were compared based on experimental tests on both welded and nonwelded specimens. A good correspondence between both techniques was observed. The δ5 method tended to result in a slightly lower estimation of crack driving force, which was explained by the difference between both CTOD definitions. Both techniques were concluded to be equivalent for the evaluation of CTOD in SE(T) specimens.
Calculation Method and Influence Law of Pavement Rut Under Dynamic Load
Authors: Li Limin , He Zhaoyi , Jiang Jianqing , Lei Ting
Published: December 2015

Based on vehicle dynamic loading, the rut calculation method is put forward, the influence law of pavement rut is obtained, and the rutting prediction for the test road was performed by employing this method. The results indicated that there is little difference between calculated rutting value and the real one of the test roads, and the maximum error is 9 %. Moreover, their deformation shapes of rutting are almost the same as a whole. Therefore, the proposed rutting calculation method is feasible for the very complex problem of rutting calculation. The influence law of pavement rut under dynamic load was studied by using this method. The results showed that high temperature, heavy load, and slow speed have important effects on rutting damage of asphalt pavement. Under heavy loads, with the temperature higher than 50°C, the repetition times of axle load more than 106, and the tire pressure higher than 0.9 MPa, the rutting depth of pavement will increase dramatically. In addition, when the vehicle velocity is smaller than 40 km/h, the rutting depth of pavement will also increase obviously with the loading duration increasing (i.e., with the vehicle velocity reducing). At the early stage of the loading process, the rutting depth of pavement increases rapidly, and as the loading time passes by, the growth rate of rutting depth gradually slows down, and finally rutting depth approaches to a fixed value. Furthermore, high modulus asphalt concrete applied in the middle course can significantly enhance the anti-rutting performance of asphalt pavement, and the anti-rutting ability of asphalt pavement can also be improved by increasing the thickness of the semi-rigid bottom layer of the base and of the surface course properly, especially of the upper layer of the surface course.
Test and Evaluation for Bonding Property Between GFRP and Concrete
Authors: Gu Xingyu , Dai Yiqing , Jiang Jiwang
Published: December 2015

Glass fiber reinforced polymer (GFRP) composite is applied widely in continuously reinforced concrete pavement (CRCP) because of its prominent advantages in properties and cost compared with conventional steel materials. This paper investigated influences of concrete strength, embedded depth, surface form, and diameter of bars on the GFRP-concrete bond performance by a series of pull-out tests. A finite element model was built to simulate the whole pull-out process. The test results showed that, within a certain range, rib depth has a positive effect on both slip control and stress improvement. Smaller rib spacing had a positive effect on controlling the slip displacement, but the diameter of bars and concrete strength had a negligible impact on both the bond strength and slip displacement. The developed finite element model (FEM) could provide similar results as the pull-out tests, and the model also demonstrated a distinct peak value in a shear stress cloud chart. Meanwhile, in order to analyze the effect of embedded depth on bond strength, a normal distribution model was utilized to fit the shear stress distribution. The analysis results retrieved from the normal distribution model, with an extreme small relative error less than 4 %, were more in line with the experimental results than the traditional average distribution model.
Road Landscape Space Enclosure Scale and Sequence Characteristics Based on Human Aesthetic Perception and Psychological Experience
Authors: Qin Xiaochun , Gao Liang , Shen Yupeng
Published: December 2015

Road landscape environments are defined in terms of road space, consisting of the pavement and the surrounding boundaries, and the various road landscape elements normally constitute the component parts of road space. The creation and organization of spatial interfaces in road landscape planning not only play an important role in transportation function planning but also create different landscape spatial atmospheres, which largely determine the space perception and psychological experience of the passengers when traveling on the road. The major constituent elements of road spatial interfaces were defined in this paper, and the conception and quantized calculation method of road space enclosure scale was proposed. The spatial characteristics and the different spatial feelings of the road solid interface, void interface, and zero interface were analyzed in detail. The quantitative relationship between space enclosure scale and people's spatial experience was established based on the solid interface of plain, cutting, and filling areas, the void interface of roadside trees, and the zero interface of filling areas and viaducts. The spatial form of road landscape environment was summarized in flat, wave, and climax types according to the arrangement and layout of landscape space sequences, and the spatial sequence characteristics and improvement means for original space were discussed. Taking Guangwu Road in the Guangdong Province in the rolling hill area of South China as the case study, the road space interface enclosure map was drawn, and the road landscape space types were analyzed according to cutting and filling conditions by employing the road design software HintCAD, which provided the primary quantitative reference for road space sequence planning and regional landscape style control to make road landscape planning fully integrated with people's aesthetic psychology and dynamic visual features.
Comparison Between Superplastic and Non-Superplastic Grade AA 5083
Authors: Giuliano G. , Samani F.
Published: December 2015

To analyze the hot-deformation behavior of aluminum alloy 5083, this work shows the results of free-forming tests at constant pressure in different pressure and temperature conditions. Results of the non-superplastic AA5083 are compared with results obtained with the same material but in superplastic conditions. Though formability is quite reduced in non-superplastic grade aluminum alloy 5083, the hot-deformation process is able to reduce operating temperature and time of final forming if forming pressure is increased.
Testing Methods on Ceramic Rolling Elements for Hybrid Bearings
Authors: Schöppl Oskar , Lube Tanja
Published: December 2015

Different manufacturing routes for ceramic balls and rollers used in hybrid bearings can lead to different microstructures and mechanical properties of a silicon nitride grade, even being delivered by one supplier. This fact, experienced by the authors, makes it necessary to do testing on the different balls or rollers themselves. This will make sure that the minimum properties on strength, fracture toughness, and microstructure requirements according to ASTM F2094/F2094M-14 and ISO 26602 are fulfilled on the bearing component and not only on special bar samples prepared for bending tests. A first approach done in the bearing industry was a simple crush test of two or three balls on top of each other. This gave a very rough estimate of a “static load rating.” The material resistance to cracks and Hertzian contact damage was tested by indentations with tungsten carbide spheres or doing impact strength testing. A first approach for “real” strength measurement of ceramic spheres was introduced by using a diametrally compressed “C-Sphere” specimen. This was further developed to be more easily machinable and was simply called “Notched ball test.” A similar test was also developed in recent times for ceramic cylindrical roller rollers, called the “Notched roller test.” The goal of this paper was to discuss and summarize test methods for strength and combinations of strength with other properties or effects like toughness and/or residual stresses for ceramic rolling elements that have been established so far for hybrid bearings. This supported the understanding for the need to establish the notched ball test, which was already established as a National Standard ÖNORM M6341:2013 in Austria, and also in ISO and ASTM.
Space Station Solar Array Joint Repair
Authors: Loewenthal Stuart , Allmon Curtis , Reznik Carter , Mcfatter Justin , Davis Robert E.
Published: December 2015

In October 2007, the International Space Station (ISS) crew noticed a vibrating camera in the vicinity of Starboard Solar Alpha Rotary Joint (SARJ). It had less than 5 months of run time when the anomaly was observed. This 3.2 m-diameter bearing joint supports solar arrays that power the station critical to its operation. The crew performed an EVA to identify what was causing the vibration. It was discovered that one of the 3 bearing tracks of this unconventional bearing had significant spalling damage. This paper discussed the SARJ’s unique bearing design and the vulnerability in its design leading to the observed anomaly. The design of an SARJ vacuum test rig was also described along with the results of a life test that validated the proposed repair should extend the life of the SARJ a minimum of 18 years on-orbit.
Impact of Synthetic Hydrocarbon in Biofuels on Two Polysulfide Aircraft Fuel-Tank Sealants
Authors: Yang Zhiyuan , Liu Hua , Ye Liwei , Chen Kai
Published: December 2015

The impacts of synthetic hydrocarbon in biofuels on two fuel-tank polysulfide sealants were systematically studied in this research. Synthetic hydrocarbon was derived from waste oils and fats and produced by hydroprocessed esters and fatty acids process (HEFA). The experimental results revealed that the volume of two polysulfide sealants shrunk after being immersed in the pure biofuels for 28 days at 93°C. Furthermore, mechanical properties, such as elongation rate and hardness, failed to satisfy the requirement of the specification. The experimental results also showed that the volume swell of two polysulfide sealants varied from jet reference fuel (JRF) more than 5 % after being immersed in the blended fuels when neat biofuel component was mixed with No. 3 jet fuel in a volume ratio of 50/50. The mechanical properties of elongation and hardness still cannot meet the requirements of the specification. The results demonstrated that synthetic hydrocarbons in biofuels would have a significant impact on the polysulfide sealants of the aircraft fuel tank.
Advances in Gypsum Technologies and Building Systems
Authors: Wessel Robert A. , Shipp Paul H. , Rosenthal Guy L.
Published: December 2015

Description

This compilation of Selected Technical Papers, STP1588, Advances in Gypsum Technologies and Building Systems, contains 11 peer-reviewed papers presented at a symposium held May 21, 2015 in Anaheim, CA. The symposium was sponsored by ASTM International Committee C11 on Gypsum and Related Building Materials and Systems and Subcommittee C11.01 on Specifications and Test Methods for Gypsum Products. The Symposium Chairpersons and STP Editors are Dr. Robert A. Wessel, Gypsum Association, Hyattsville, MD, USA and Dr. Paul H. Shipp and Dr. Guy L. Rosenthal, USG Corporation, Libertyville, IL, USA.
Effects of Chemical Modification on Calcium Sulfate Castings Exposed to High Temperature
Authors: Engbrecht Dick C. , Hirschfeld Deidre A.
Published: December 2015

Calcium sulfate dihydrate is the primary ingredient in passive gypsum drywall fire barrier systems. The endothermic properties of calcium sulfate dihydrate are well known and exploited in these systems. Researchers in fire modeling have extensively studied the endothermic properties of gypsum up to 500°C. This study reports on the influence of selected chemical and mineral constituents on dimensional and thermal property changes in gypsum casts in excess of the critical crystal dehydration temperature (between 500° and 1000°C). Gypsum from natural and flue gas desulfurization (FGD) sources used in commercial operations were evaluated for changes by differential thermal analysis/thermogravimetric analysis (DTA/TGA), Fourier transform infrared (FTIR) spectroscopy, Raman spectra analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Petalite and Gerstley borate were added to a basic formula used in commercially manufactured wallboard for fire barrier systems. The analysis of the data identified significant changes in density and hardness of the gypsum casts related to the addition of Petalite and Gerstley borate.
Fifty Years of Test and Measurement of Gypsum Drywall
Authors: Danks Michael G.
Published: December 2015

This paper is provided as a historical review of the growth of the gypsum panel industry and the changes in test methodology, measurement tools, and techniques for gypsum panels over the last fifty-plus years. In order to facilitate the general understanding of these changes, a short section covering the science of numbers and measurement is included at the beginning to refresh the readers' knowledge or to initiate those unfamiliar with the basic science of test and measures. The first section of the review covers the 1950s into the 1970s and the industry's growth primarily as a provider of residential building materials. The second section of the review covers the growth of the industry into high-rise and commercial construction from the mid-1970s through to the present day. Because this chapter consists largely of a historical view of the business, the changes in testing, and the addition of new measures that have occurred through the years, there is no attempt to provide a causation or correlation conclusion. As a conclusion, the continuing changes in testing methods, measurement requirements, and the potential for future changes in the gypsum industry will be discussed. It is hoped that the audience will formulate personal ideas on what changes are likely to continue into the future.
Measurement of Free and Combined Water of Gypsum
Authors: Flumiani Mark R. , Turner Jim , Trimble Virginia
Published: December 2015

The existing standard ASTM C471 Standard Test Methods for Chemical Analysis of Gypsum and Gypsum Products describes manual gravimetric analytical methods for evaluating the free and combined water of gypsum materials, including natural gypsum, synthetic gypsum, rehydrated plasters, and gypsum board. The existing method describes a sample condition, sample size, time of exposure, and temperature of exposure for each measurement. It is common current industry practice to use automatic moisture balance machines to perform this measurement to achieve fast results with minimal labor. Although the automated measurement is obviously more efficient, no standard currently exists for the conditions and settings of such systems. Also, different moisture balance equipment have varying features and specifications. Therefore, there exists a possibility for significant variability among what are typically considered equivalent measurements from machine to machine and versus accepted manual methods. In 2011, the ASTM C11 Committee undertook the task of updating the existing standard to include automated moisture balance methods. In a preliminary experiment described here, a few variations in automated methods were compared to the existing manual methods to evaluate differences in average measurement results and standard deviation of these results. As a result of this preliminary work, an updated standard will be submitted in 2015, and a following interlaboratory study is planned for 2016 to specifically define the precision and bias of both methods.
Innovation in Cold-Formed Steel Framing
Authors: Kerner Michael C. , Smith J. R.
Published: December 2015

ASTM C645-14 Standard Specification for Nonstructural Steel Framing Members and ASTM C955-11c Standard Specification for Load-Bearing (Transverse and Axial) Steel Studs, Runners (Tracks), and Bracing or Bridging for Screw Application of Gypsum Panel Products and Metal Plaster Bases define the standard properties of nonstructural and structural framing members. The past quarter century has seen a dramatic increase in the use of nonstructural, ASTM C645-compliant, cold-formed steel framing members for use in interior construction assemblies—as well as increased use of structural, ASTM C955-compliant, cold-formed steel framing members for uses in interior and exterior structural assemblies. Along with an increase in the use of these innovative and versatile construction products, significant technology innovations that improved the structural performance, coating durability, quality assurance, and material efficiency of the framing members have also taken place. These two specifications, which govern these members, have undergone dramatic changes that have resulted in more detailed and complete specifications. Performance requirements were added to the standards to complement the prescriptive requirements. Concurrently, industry organizations such as the Steel Framing Industry Association (SFIA) have developed and adopted code compliance certification programs to provide quality assurance to users of their various members' products. This paper reviews the history and evolution of the framing standards and describes the ongoing efforts to adapt these standards to industry innovations. The paper will also explore the current quality assurance practices that evaluate and audit equivalent technology (EQ).
Evolution and Innovation in Drywall Joint and Corner Finishing, 1900–2015
Authors: Rosenthal Guy L.
Published: December 2015

Reinforcement and aesthetic finishing of drywall joints and corners has seen steady evolution over the past century. Products on the market include numerous woven, nonwoven, and plastic tapes for joint reinforcement, and the patent literature outlines even more innovative, if not always practical, joint treatment strategies. The introduction of flexible plastic corner products has provided contractors with a variety of new options for robust and efficient finishing of off-angle corners and sweeping arches. The paper reviews the patent literature to highlight how new materials, new product designs, and new manufacturing technologies have addressed the challenges of finishing gypsum wallboard joints and corners and how various innovative solutions have increased efficiency and performance.
Fifty Shades of Green: Gypsum Board Manufacturers and the Evolution of Green Building
Authors: Meima Stephen , Hines Susan
Published: December 2015

Despite, or perhaps because of, the rapid growth of green construction over the past 20 years, consensus over what products are appropriate for use in sustainable building remains in flux. Many factors are at play within the green building movement, including different and sometimes competing green goals and rating systems. Quantifying and evaluating the sustainability of building materials has proven difficult, adding to confusion. However, building on the work of standards setting bodies such as ASTM, tools are emerging that allow consumers to make choices among various building products based not only on performance but also on the total environmental impact of the product itself, including embodied energy, global warming potential, resource use, and pollution caused by or created by the material during its manufacturing process or anticipated life span (or both). This “life cycle analysis” of products allows consumers and their agents or designers to make informed choices and more sustainable trade-offs when selecting building products. The Gypsum Association's recent experience producing product category rules (PCR), a life cycle assessment (LCA), and an environmental product declaration (EPD) for 5/8-in Type X gypsum board offers insight into the sometimes complex process of developing these LCA tools. The association's lessons learned and future plans for providing additional tools for other generic gypsum panel products offer a valuable perspective on a sustainability initiative that is gaining increasing traction among producers and consumers of building products.
Fire Resistance Testing of Fire Rated Gypsum Wallboard—The Last 20 Years
Authors: Stacy Howard , Priest Deg
Published: December 2015

Since the 1920s, fire protection design approaches along with the model building codes have traditionally relied on a prescriptive-based system utilizing fire resistance ratings of wall, floor, and roof assemblies achieved from standard fire tests, including ASTM E119 and UL 263. Much has changed over the last 20 years, and the aim of this presentation is to provide an overview of the advances in “state of the art” fire resistance testing methodologies and approaches where the evaluation and listing of fire rated gypsum board assemblies is concerned. The discussion will include: (1) advances in ASTM E119 furnace construction, burner design, data collection, and electronic measurement techniques; (2) improvements in loading techniques of wall and floor assemblies; (3) a summary of the North American Fire Testing Laboratories Consortium (NAFTL) interlaboratory study of the consistency of fire resistance testing of a common gypsum/steel-stud assembly and the development of a “precision and bias” statement for the ASTM E119 standard; and (4) a summary of recommended improvements.
Excitatory Postrhinal Projections to Principal Cells in the Medial Entorhinal Cortex
Authors: Koganezawa Noriko , Gisetstad Ragnhild , Husby Ellen , Doan Thanh P. , Witter Menno P.
Published: December 2015

The postrhinal cortex (POR) provides substantial input to the entorhinal cortex, mainly targeting superficial layers of the medial entorhinal cortex (MEC). Major inputs to POR originate in the visual and parietal cortex, thus providing neurons in MEC with a subset of cortical information relevant to their spatial firing properties. The POR takes a position that is comparable with that of the perirhinal cortex (PER) with regard to the lateral entorhinal cortex (LEC). Neurons in LEC and MEC show different functional properties likely reflecting differences in their respective inputs. Projections from PER to LEC exert a main inhibitory influence, which may relate to the sparse object-selective firing in LEC. In view of the continuous, spatially modulated firing properties of principal neurons in MEC, we tested in rats the hypothesis that projections from POR to MEC are functionally different from the PER-to-LEC counterpart in providing an excitatory drive to MEC. Our combined confocal and quantitative electron-microscopic observations indicated that POR projections target mainly principal cells in MEC, including neurons that project to the hippocampus. The ultrastructure of the majority of the synapses indicated that they are excitatory. Voltage-sensitive dye imaging in sagittal slices confirmed this morphologically derived conclusion, showing that the MEC network always responded with an overall depolarization, indicative for net excitatory transmission.In vitrosingle-cell recordings from principal cells showed only excitatory responses upon POR stimulation. These results show that POR provides an excitatory projection to MEC, differing fundamentally from the inhibitory projection of PER to LEC.

SIGNIFICANCE STATEMENTThe study provides anatomical and electrophysiological data indicating that projections from the postrhinal cortex to the medial entorhinal cortex (MEC) are excitatory, providing the substrate for high probability of information transfer and thus a continuous input stream into MEC. This is a relevant component of the spatial navigational network found in MEC. The findings are in contrast to previous reports on the parallel pathway from the perirhinal cortex to the lateral entorhinal cortex. This pathway, characterized by a preponderance of inhibitory connections, mediates information transfer with a low probability, likely related to the discontinuous object-related firing of neurons in the lateral entorhinal cortex.
Brief Dark Exposure Reduces Tonic Inhibition in Visual Cortex
Authors: Huang Shiyong , Hokenson Kristen , Bandyopadhyay Sabita , Russek Shelley J. , Kirkwood Alfredo
Published: December 2015

Tonic inhibition mediated by extrasynaptic GABAAreceptors (GABARs) sensing ambient levels of GABA can profoundly alter the membrane input resistance to affect cellular excitability. Therefore, regulation of tonic inhibition is an attractive mechanism to control the levels of cortical firing. In cortical pyramidal cells, tonic inhibition is regulated by age and several neurotransmitters and is affected by stroke and epilepsy. However, the possible role of sensory experience has not been examined. Here, we report that a brief 2-day exposure to dark reduces by 1/3 the inhibitory tonic conductance recorded in layer II/III pyramidal cells of the mouse juvenile (postnatal day 12–27) visual cortex. In these cells, tonic inhibition is carried primarily by GABARs containing the δ subunit. Consistently, the dark exposure reduction in conductance was associated with a reduction in δ subunit levels, which were not affected in control frontal cortex. We propose that a deprivation-induced reduction in tonic inhibition might serve a homeostatic function by increasing the firing levels of cells in deprived cortical circuits.

SIGNIFICANCE STATEMENTPreviousin vivostudies reported rapid increases in spontaneous activity after visual deprivation. These adaptive responses to deprivation are believed to reflect a reduction in the recruitment of inhibitory circuits. Notably, the possible role of tonic GABAergic inhibition, which strongly limits cellular and network excitability, has not been examined. We report that a brief 2-day exposure to dark reduces both the conductance of tonic inhibition in layer 2/3 pyramidal cells and the expression of receptors containing the δ-GABAAreceptor subunit, the principal carrier of tonic inhibition in these cells. These results suggest that the early phases of homeostatic adaptations to sensory deprivation might result from modulation of GABAergic function at multiple levels.
Synaptic Targets of Medial Septal Projections in the Hippocampus and Extrahippocampal Cortices of the Mouse
Authors: Unal Gunes , Joshi Abhilasha , Viney Tim J. , Kis Viktor , Somogyi Peter
Published: December 2015

Temporal coordination of neuronal assemblies among cortical areas is essential for behavioral performance. GABAergic projections from the medial septum and diagonal band complex exclusively innervate GABAergic interneurons in the rat hippocampus, contributing to the coordination of neuronal activity, including the generation of theta oscillations. Much less is known about the synaptic target neurons outside the hippocampus. To reveal the contribution of synaptic circuits involving the medial septum of mice, we have identified postsynaptic cortical neurons in wild-type and parvalbumin-Cre knock-in mice. Anterograde axonal tracing from the septum revealed extensive innervation of the hippocampus as well as the subiculum, presubiculum, parasubiculum, the medial and lateral entorhinal cortices, and the retrosplenial cortex. In all examined cortical regions, many septal GABAergic boutons were in close apposition to somata or dendrites immunopositive for interneuron cell-type molecular markers, such as parvalbumin, calbindin, calretinin, N-terminal EF-hand calcium-binding protein 1, cholecystokinin, reelin, or a combination of these molecules. Electron microscopic observations revealed septal boutons forming axosomatic or axodendritic type II synapses. In the CA1 region of hippocampus, septal GABAergic projections exclusively targeted interneurons. In the retrosplenial cortex, 93% of identified postsynaptic targets belonged to interneurons and the rest to pyramidal cells. These results suggest that the GABAergic innervation from the medial septum and diagonal band complex contributes to temporal coordination of neuronal activity via several types of cortical GABAergic interneurons in both hippocampal and extrahippocampal cortices. Oscillatory septal neuronal firing at delta, theta, and gamma frequencies may phase interneuron activity.

SIGNIFICANCE STATEMENTDiverse types of GABAergic interneurons coordinate the firing of cortical principal cells required for memory processes. During wakefulness and rapid eye movement sleep, the rhythmic firing of cortical GABAergic neurons plays a key role in governing network activity. We investigated subcortical GABAergic projections in the mouse that extend from the medial septum/diagonal band nuclei to GABAergic neurons in the hippocampus and related extrahippocampal cortical areas, including the medial entorhinal cortex. These areas contribute to navigation and show theta rhythmic activity. We found selective GABAergic targeting of different groups of cortical GABAergic neurons, immunoreactive for combinations of cell-type markers. As septal GABAergic neurons also fire rhythmically, their selective innervation of cortical GABAergic neurons suggests an oscillatory synchronization of neuronal activity across functionally related areas.
Visualization of Ca2+Filling Mechanisms upon Synaptic Inputs in the Endoplasmic Reticulum of Cerebellar Purkinje Cells
Authors: Okubo Yohei , Suzuki Junji , Kanemaru Kazunori , Nakamura Naotoshi , Shibata Tatsuo , Iino Masamitsu
Published: December 2015

The endoplasmic reticulum (ER) plays crucial roles in intracellular Ca2+signaling, serving as both a source and sink of Ca2+, and regulating a variety of physiological and pathophysiological events in neurons in the brain. However, spatiotemporal Ca2+dynamics within the ER in central neurons remain to be characterized. In this study, we visualized synaptic activity-dependent ER Ca2+dynamics in mouse cerebellar Purkinje cells (PCs) using an ER-targeted genetically encoded Ca2+indicator, G-CEPIA1er. We used brief parallel fiber stimulation to induce a local decrease in the ER luminal Ca2+concentration ([Ca2+]ER) in dendrites and spines. In this experimental system, the recovery of [Ca2+]ERtakes several seconds, and recovery half-time depends on the extent of ER Ca2+depletion. By combining imaging analysis and numerical simulation, we show that the intraluminal diffusion of Ca2+, rather than Ca2+reuptake, is the dominant mechanism for the replenishment of the local [Ca2+]ERdepletion immediately following the stimulation. In spines, the ER filled almost simultaneously with parent dendrites, suggesting that the ER within the spine neck does not represent a significant barrier to Ca2+diffusion. Furthermore, we found that repetitive climbing fiber stimulation, which induces cytosolic Ca2+spikes in PCs, cumulatively increased [Ca2+]ER. These results indicate that the neuronal ER functions both as an intracellular tunnel to redistribute stored Ca2+within the neurons, and as a leaky integrator of Ca2+spike-inducing synaptic inputs.

SIGNIFICANCE STATEMENTCa2+is a key messenger that regulates neuronal functions in the brain. Although the endoplasmic reticulum (ER) plays indispensable roles as a source and sink of Ca2+, technical difficulties have impeded the analysis of Ca2+dynamics within the ER. In this study, we have used a genetically encoded ER Ca2+indicator to visualize Ca2+dynamics within the neuronal ER. We found that Ca2+-mobilizing synaptic inputs locally decreased the ER Ca2+concentration, followed by Ca2+replenishment by intraluminal Ca2+diffusion throughout the ER of dendrites and spines. Furthermore, Ca2+spike-inducing synaptic inputs cumulatively increased the Ca2+content of the ER. Thus, our study indicates that the ER functions both as a tunnel to redistribute stored Ca2+and as a leaky integrator of synaptic inputs.