Reported Test Results Research Articles

Computational investigation of the effects of knee airbag design on the interaction with occupant lower extremity in frontal and oblique impacts

ABSTRACTObjective: The lower extremity of the occupant represents the most frequently injured body region in motor vehicle crashes. Knee airbags (KABs) have been implemented as a potential countermeasure to reduce lower extremity injuries. Despite the increasing prevalence of KABs in vehicles, the biomechanical interaction of the human lower extremity with the KAB has not been well characterized. This study uses computational models of the human body and KABs to explore how KAB design may influence the impact response of the occupant's lower extremities.Methods: The analysis was conducted using a 50th percentile male occupant human body model with deployed KABs in a simplified vehicle interior. The 2 common KAB design types, bottom-deploy KAB (BKAB) and rear-deploy KAB (RKAB), were both included. A state-of-the-art airbag modeling technique, the corpuscular particle method, was adopted to represent the deployment dynamics of the unfolding airbags. Validation of the environment model was performed based on previously reported test results. The kinematic responses of the occupant lower extremities were compared under both KAB designs, 2 seating configurations (in-position and out-of-position), and 3 loading conditions (static, frontal, and oblique impacts). A linear statistical model was used to assess factor significance considering the impact responses of the occupant lower extremities.Results: The presence of a KAB had a significant influence on the lower extremity kinematics compared to no KAB (P <.05) by providing early restraint and distributing contact force on the legs during airbag deployment. For in-position occupants, the KAB generally tended to decrease tibia loadings. The RKAB led to greater lateral motion of the legs compared to the BKAB, resulting in higher lateral displacement at the knee joint and abduction angle change (51.2 ± 21.7 mm and 15° ± 6.0°) over the dynamic loading conditions. Change in the seating position led to a significant difference in occupant kinematic and kinetic parameters (P <.05). For the out-of-position (forward-seated) occupant, the earlier contact between the lower extremity and the deploying KAB resulted in 28.4° ± 5.8° greater abduction, regardless of crash scenarios. Both KAB types reduced the axial force in the femur relative to no KAB. Overall, the out-of-position occupant sustained a raised axial force and bending moment of the tibia by 0.8 ± 0.2 kN and 21.1 ± 8.7 Nm regardless of restraint use.Conclusions: The current study provided a preliminary computational examination on KAB designs based on a limited set of configurations in an idealized vehicle interior. Results suggested that the BKAB tended to provide more coverage and less leg abduction compared to the RKAB in oblique impact and/or the selected out-of-position scenario. An out-of-position occupant was associated with larger abduction and lower extremity loads over all occupant configurations. Further investigations are recommended to obtain a full understanding of the KAB performance in a more realistic vehicle environment.

Experimental Behavior of Concrete-Filled Stainless Steel Tubular Columns under Cyclic Lateral Loading

Concrete-filled stainless steel tubular (CFSST) columns have attracted increasing research interests in recent years; however, It seems that the behavior of this type of innovative column under cyclic loading has not been addressed sufficiently so far. This paper reports test results of 10 CFSST columns under constant axial load and cyclically increasing flexural loading. The main parameters varied in the experiments were axial load level, cross-sectional type, and concrete type. The influences of these parameters on strength, ductility, stiffness, and energy dissipation were investigated. It was found that CFSST columns exhibited excellent energy dissipation and ductility, even when the specimens were subjected to high axial loads. The hysteretic behavior of the tested CFSST columns was compared to that of their carbon steel composite counterparts reported in the literature. Several existing design codes were used to predict the ultimate strength and flexural stiffness of the test specimens, and some suggestions are proposed accordingly for designing CFSST columns.

Impact of Payer Constraints on Access to Genetic Testing.

With increased demand for hereditary cancer genetic testing, some large national health-care insurance payers (LNHPs) have implemented policies to minimize inappropriate testing by mandating consultation with a geneticist or genetic counselor (GC). We hypothesized such a restriction would reduce access and appropriate testing. Test cancellation rates (ie, tests ordered that did not result in a reported test result), mutation-positive rates, and turnaround times for comprehensive BRCA1/2 testing for a study LNHP that implemented a GC-mandate policy were determined over the 12 months before and after policy implementation (excluding a 4-month transition period). Cancellation rates were evaluated based on the reason for cancellation, National Comprehensive Cancer Network testing criteria, and self-identified ancestry. A control LNHP was evaluated over the same period for comparison. The study LNHP cancellation rate increased from 13.3% to 42.1% ( P < .001) after policy implementation. This increase was also observed when only individuals who met National Comprehensive Cancer Network criteria for hereditary breast and ovarian cancer testing were considered (9.5% to 37.7%; P < .001). Cancellation rates increased after policy introduction for all ancestries; however, this was more pronounced among individuals of African or Latin American ancestry, for whom cancellation rates rose to 48.9% and 49.6%, respectively, compared with 33.9% for individuals of European ancestry. Over this same time period, control LNHP cancellation rates decreased or stayed the same for all subgroups. These findings demonstrate that a GC-mandate policy implemented by a LNHP substantially decreased access to appropriate genetic testing, disproportionately impacting minority populations without any evidence that inappropriate testing was decreased.

Field performance of concrete pavement incorporating recycled concrete aggregate

This paper reports test results of a field-oriented study carried out to demonstrate the performance of recycled concrete aggregate (RCA) for use in the construction of rigid pavement. Properties of eight concrete mixtures containing RCA were first compared to those of a reference mixture. Two mixtures proportioned with 30% and 40% of coarse RCA along with the reference concrete were then used for field implementation, which involved casting a 300-m long pavement section in St. Louis, Missouri. Samples were taken during slip-form pavement construction. Core samples were extracted at 120days to determine in-situ properties. Instrumentation was incorporated to monitor the long-term deformation of different pavement sections. Incorporation of 30% and 40% RCA reduced the 91-day compressive strength by 7% and 12%, and the 56-day modulus of elasticity by 22% and 14%, respectively. The 56-day splitting tensile strength and flexural strength values of the two RCA mixtures were similar to those of the reference concrete. Mixtures exhibited similar performance in terms of durability against abrasion, freeze and thaw cycles, and rapid chloride ion permeability. An increase of 100με in shrinkage was observed for the 40% RCA compared to the reference concrete. However, all field investigated mixtures exhibited similar long-term deformation patterns and magnitudes. In-situ deformation of all pavement sections was limited to 150με at sensor locations.

Effect of Aggregate Size on Punching Strength of Reinforced Concrete Slabs

This paper reports test results of flat slab cast from micro-concrete and normal concrete subjected to concentric punching shear. Although the punching shear failure mechanism of micro-concrete slabs was very similar to that of normal-concrete slabs, the punching shear capacity is reduced to about 73% due to the reduction in transferred shear stresses across shear cracks by aggregate interlock. Therefore, a shear retention factor of 0.7 is suggested to be applied in estimating the punching shear strength of micro-concrete slabs.

Foreign exchange data crawling and analysis for knowledge discovery leading to informative decision making

Foreign exchange refers to the process of converting/changing money from one currency to another, e.g., from euro to US dollar. This kind of exchange is valuable and attractive because the value of various currencies may change over time, leading to gain or loss in terms of the overall value. Further, the foreign exchange market is growing rapidly and the development in technology has influenced all aspects of our daily life, including foreign currencies trading. Thus, there has been a major shift to electronic trading which has brought together the need for sophisticated techniques capable of monitoring the market in real time. To contribute to this domain, the research described in this paper covers the development of a framework which enables real time acquisition of data from a set of currency trading entities and fast data analysis. The framework also allows streaming and visualization of historical (previous) and current currency prices in close to real time. Finally, the framework benchmarks every monitored broker to decide whether he/she is trustworthy. The reported test results demonstrate the applicability and effectiveness of the developed framework. An additional value of the developed framework is attributed to its utilization by a domain expert who has guided the whole development process.

Study of a detector system for high-energy astrophysical objects using a combination of plastic scintillator and MPPC

We have investigated a hard X-ray detector system using a combination of a plastic scintillator and multi-pixel photon counters (MPPC). Photomultiplier tubes (PMTs) have typically been adopted to read scintillators because of their high gain and large photoelectric surface, and studies on PMT and scintillator systems are well advanced. However, PMTs have limitations; for example, they are relatively large in size, require high voltage to operate, and cannot be used in strong magnetic fields. On the other hand, MPPCs do not have such limitations and instead possess high quantum efficiency and a large compact size. Therefore, we have studied a detector system that combines an MPPC with a plastic scintillator. The system is primarily intended to be used for polarization measurements of high-energy astrophysical objects. We achieved an energy threshold of as low as ~5keV while operating the detector at low temperature (−10°C), reading the signal with short integration time (50ns), and using a low-noise MPPC. We also confirmed that the light yield of our MPPC+plastic scintillator system is comparable to that obtained using a conventional PMT to read the scintillator signal. Herein, we report test results and future prospects.

Reinforced ultra-lightweight cement composite flat slabs: Experiments and analysis

Novel lightweight flat slabs made of ultra-lightweight cement composite (ULCC) with density of 1329–1649kg/m3 and strength of 52.0–87.3MPa have been developed for buildings and offshore constructions. This paper studied the structural behaviors of the reinforced ULCC flat slabs under concentrated loading through a 14-specimen test program. The test program aimed to investigate the influences of shear span, flexural reinforcing ratio, depth of the section, and volume fraction of fibers on the failure mode, load deflection behaviors, and punching shear resistances of the ULCC flat slabs. Analytical models on predicting the tensile versus compressive strength relationships of ULCC were developed through regression analysis on 102 test data, and this developed relationship was then used to develop analytical models on punching shear resistance of ULCC flat slabs. Analytical models were developed to predict the punching shear resistance of the ULCC flat slabs through modifying the code provisions. The accuracy of these developed models was confirmed through validations against the reported test results.

Aconselhamento em doenças sexualmente transmissíveis na atenção primária: percepção e prática profissional

Resumo Objetivo Compreender percepção dos profissionais sobre a prática do aconselhamento em doenças sexualmente transmissíveis/HIV na atenção primária. Métodos Estudo qualitativo realizado com enfermeiros e médicos que atuam na atenção primária de saúde. A coleta de dados ocorreu mediante a técnica grupo focal, ancorada no Reporting Pesquisa Qualitativa - COREQ. A análise dos dados foi submetida aos passos da Fenomenologia Social, Alfred Schütz, evidenciando-se as categorias do estudo. Resultados Os profissionais realizam o aconselhamento de forma reduzida baseada na orientação para prevenção de doenças. Essa prática está inserida no planejamento familiar e atividades escolares. O acesso do usuário com doença sexualmente transmissível é marcado por procura mínima. No acolhimento, apontou-se a priorização do atendimento dos casos. Constataram-se sensação de despreparo e insegurança na comunicação do resultado de exames, dificuldades para o aconselhamento na visita domiciliar, manutenção do sigilo e da privacidade de informações dos usuários. Conclusão Os profissionais percebem o aconselhamento como uma prática relevante, porém acompanhada de limitações e barreiras na realização.

Underestimation of plasma level of factor V coagulant activity and fibrinogen concentration together with prolonged prothrombin time, activated partial thromboplastin time and thrombin time can result from pre-analytical very low calcium level in citrated sample tube.

Pre-analytical phase is a critical step in the haemostasis laboratory cycle. Numerous variations affect tests results, and it is crucial to detect them in order to reject improper specimens before reporting test results. Comparing to prior results or requesting, a repeat sample can help in pre-analytical irregularity assessment. Each time a sample addressed to our laboratory displayed aberrant results or discordant with a prior report, another specimen was asked and both were analysed through calcium (Ca) level, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen concentration, factor II, factor VII+X and factor V coagulant activity measurements. Among these, all the primary citrated samples from inpatients without anticoagulant treatment, displaying very low calcium level ('Ca 0' samples), were selected for this 2 years study. A total of 17 samples could be identified. Ca level in their paired repeat samples was always >1.00 mmol/L. Coagulation testing for 'Ca 0' samples showed a significant prolongation of PT, APTT, TT and a significant decrease for fibrinogen concentration and factor V coagulant activity. We identified factor V coagulant activity, as the parameter with the most important variation in case of very low calcium level in presumed citrated sample tubes probably contaminated with EDTA.

Medical record convergence for hla reporting across the enterprise

Aim One of Mayo Clinic’s missions is to standardize care through an integrated clinical practice. Reporting histocompatibility results is very complex and HLA labs have different ways of interpreting results. By standardizing across the three sites we improve the interchangeability of test results, reduce resources to support our practice, provide the best standard of care for our patients and support for our physicians for the Mayo paired kidney exchange program. Methods Integration was defined as: Each lab will use HistoTrac as the lab management system. HistoTrac will interface with the lab integrated system (LIS) for processing of orders and reporting results to the medical record. Each lab will report the same discreet result values and interpretive reports. Each lab will use the same vendor and lot number if possible for antibody and typing tests. A project group was created which includes: a director and technical specialist from each site, a business analyst, and a computer programmer. This team worked together using conference calls and web meetings to establish standardization for reporting HLA typing, antibody and crossmatch results. Results The results reported at each site will use the same test definitions, reporting templates, and will be transferred to the LIS. We encountered some obstacles due to: lab practice differences, transplant policies and business requirements. The convergence effort is still ongoing at each site: MN: update reporting and implement interpretive reports AZ: implement an interface to the LIS and update interpretive reports FL: implement HistoTrac with an interface to the LIS and update interpretive reports Conclusion All histocompatibility data and interpretive reports will be available in the medical record at each mayo site. Convergence of reporting test results will improve the communication and understanding when evaluating a patient while making the process cost effective. The next step in convergence is reporting to one medical record at all three sites. Download full-size image

The adoption of a new diagnostic technology for tuberculosis in two Brazilian cities from the perspective of patients and healthcare workers: a qualitative study.

BackgroundThis article presents the qualitative component linked to a larger study of implementation of the Xpert™ MTB/Rif technology in two Brazilian cities. Despite intrinsic advantages of new health technologies, its introduction can be disruptive to existing routines, and it is thus important to understand how these innovations are perceived by the different groups involved in its regular use.MethodsThis study was based on semi-structured interviews with patients, lab technicians, health care workers and managers involved with diagnosis and care of Tuberculosis (TB). The interviews had their content analyzed in order to abstract the different perspectives for the various actors.ResultsFor patients the changes were not perceived as significant, since their greatest concerns were related to treatment and the stigma associated with TB. The professionals in general welcomed the new technique, which dramatically decreases the workload, time and reliability of diagnosis, in their view. However, we noted difficulties with the concomitant implementation of new IT technology for recording and reporting test results, which negatively impacted the time necessary to get lab diagnosis to physicians.ConclusionsThrough this analysis we detected some bottlenecks in the surrounding environment, not necessarily linked to the technology itself but which could hamper considerably its advantages.

Drained Instability in Loose Granular Material

AbstractThe constant shear drained (CSD) test is considered an appropriate test to simulate the instability behavior of soils in slopes under water infiltration conditions or lateral stress relief. However, contradiction of the drained instability in loose granular material exists in the reported test results, which is considered because of the condition of constant deviatoric stress (q) not strictly satisfied in the literature. Because the variation of q during the CSD test has significant effects on the test results, more data from tests under a true constant q condition are needed to clarify this subject. In this paper, CSD and conventional undrained triaxial tests in both compressive and extensive loading were performed to investigate the instability behavior of loose sand. All the CSD tests were conducted by advanced variable confining pressure triaxial apparatus, in which a true constant q was maintained during the test; thus, more reliable results were obtained. It is observed experimentally that w...

Analyses of Transient Behaviors of No-Insulation REBCO Pancake Coils During Sudden Discharging and Overcurrent.

Stability margin of a high-temperature superconducting (HTS) coil is two or three orders of magnitude greater than that of a low-temperature superconducting coil. In recent years, many papers have reported test results of turn-to-turn no-insulation (NI) HTS coils having extremely enhanced thermal stability, such that burnout never occurs in an NI coil, even at an operating current exceeding 2.5 times the critical current. Thus, The main goal of this paper is to clarify transient electromagnetic and thermal behaviors and mechanism of the high thermal stability in an NI REBCO coil. A partial element equivalent circuit (PEEC) model is proposed for the numerical simulation of an NI REBCO coil, which considers a local electrical contact resistance between turns, an I-V characteristic of an REBCO tape, and local self and mutual inductances of the NI REBCO coil. Using the PEEC model, we investigate the influence of the turn-to-turn contact resistance on the transient behavior of the NI REBCO coil during sudden discharging. We also perform thermal conduction analyses with the PEEC model to clarify the transient behavior of an NI REBCO coil during an overcurrent operation.

ERSFQ 4-to-16 Decoder for Energy-Efficient RAM

We designed, fabricated, and demonstrated an energy-efficient ERSFQ 4-bit decoder. The first version of the decoder is designed and fabricated using HYPRES legacy 1.0-μm four-layer 4.5-kA/cm 2 process. It occupies an area of 700 μm × 1800 μm, which is to be reduced to 160 μm × 400 μm once fabricated using HYPRES's RIPPLE-2 0.25-μm six-layer process. The decoder features ±13% dc bias current operating margins and below 70-aJ energy consumption per one address select operation. We report test results of the decoder and discuss its future implementation in cryogenic random access memory devices, including magnetic memory devices.

Planarized, Extendible, Multilayer Fabrication Process for Superconducting Electronics

We report on technique and results for superconductor electronics fabrication process, featuring customizable number of planarized superconducting layers. The novel technique enhanced yield on stackable vias of our standard planarized process (RIPPLE) by eliminating the need for an additional deposition of aluminum as an etch stop in the metal-via stack. The drawback of the previous approach was the difficulty in processing aluminum using either wet or dry etch mechanisms. Here, we discuss details of the novel fabrication process flow and its realization for 4.5 kA/cm2 fabrication process with six Nb layers with two fully planarized layers. We report test results of various planarization diagnostics structures, accounting the influence of topology on Josephson junction quality, as well as yield and critical current of via stacks. We also report on inductance measurement results providing information on interlayer dielectric thickness for planarized layers; confirming a good uniformity over the wafer. Basic components of superconducting logic such as dc/SFQ, SFQ/dc converters, Josephson transmission lines (JTLs), and simple digital circuits such as half-adder (HA) have been designed, fabricated and tested using either conventional (RSFQ) or energy-efficient (ERSFQ) approach. The ERSFQ HA cells with bias inductors fabricated in two planarized layers were shown to function with the operational margins of +/-22%.

The Platelet Function Analyser (PFA)-100 and von Willebrand disease: a story well over 16 years in the making.

The Platelet Function Analyser (PFA)-100 and von Willebrand disease: a story well over 16 years in the making.

Experimental study on the thermal performance and pressure drop of a solar air collector based on flat micro-heat pipe arrays

A new solar air collector that combines the use of flat micro-heat pipe arrays (FMHPA) and evacuated tube is developed and investigated. Using FMHPA as the central transporting component in a solar air collector is an effective approach to improve the collector’s thermal properties and reduce its pressure drop. The thermal properties and pressure drop of the FMHPA solar air collector are analyzed in detail. The main objective of this paper is to report test results of the FMHPA solar air collectors which includes the effects of different seasons and airflow rates on the thermal efficiency and the pressure drop of the air collector. In summer, the thermal efficiency of the collector reaches 73% under stable operation. In the testing airflow range condition, the pressure drop is less than 25Pa when the flow rate is below 201.6m3/h. The relative uncertainty of thermal efficiency is approximately 7.73%.

Performance investigation on solar thermal conversion of a conical cavity receiver employing a beam-down solar tower concentrator

Development of a beam-down solar tower (BST) with strong wind-resistance heliostats is a particular topic of active research. A BST system, equipped with three linear Fresnel heliostat modules, corresponding beam-down concentrators, and a central cavity receiver with a spiral tube, has been introduced, experimentally investigated and theoretically analyzed in this paper. The elaborate derivation process of sun-tracking formulas for the BST collector has been implemented. In addition, detailed numerical models for thermal behaviors of the conical cavity receiver with the spiral tube, on the basis of three-dimensional Computing Finite Dynamics (CFD) method, have been developed and validated with experimental data. The objective of this paper is to report test results of the conical receiver equipped the BST concentrator, and to numerically evaluate conversion performance of the solar thermal process including the heat flux distribution on the absorber surface, heat losses, as well as instantaneous thermal efficiencies, thereby providing useful data for the optimization of the cavity receiver. Experimental results and numerical prediction indicate that instantaneous thermal efficiencies of about 60% and 39% can be reached at differences of 81K and 181K between inlet and ambient temperatures under water and Therminol VP-1 flow rates of 0.5l/s, respectively. The operational volume flow rates of 0.25l/s and 0.35l/s are respectively suggested to the conical cavity receiver using water and Therminol VP-1 under the geometry and operational conditions in this paper. The optimal conical angle of 100° has a minimum heat loss leading to obtain a maximum thermal efficiency.

Effect of Arc Electrode Geometry and Distance on Cotton Shirt Ignition

The results of experimental arc testing of a nontreated cotton T-shirt with three different geometrical arc electrode arrangements are presented and discussed. Different geometries of arc electrodes result in different electromagnetic interactions of an arc current with current flowing in arc electrodes, which, in turn, cause very different arc behaviors. The ignition threshold of a T-shirt (arc energy attributed to 50% probability of ignition) was determined using the following: 1) apparatus for mannequin arc test methods ASTM F2621 and IEC 61482-1-1 (Method B) with vertical butted arc electrodes in open air (open arc); 2) apparatus for arc-in-a-box (box) test method IEC 61482-1-2 with vertical butted arc electrodes placed in a box; and 3) nonstandard end-of-line (ejected arc) apparatus with parallel horizontal arc electrodes in open air. Test parameters for the ignition threshold included the following: 1) 4-, 8-, and 16-kA arc current levels for each test apparatus; 2) same distance of 18 in from arc electrodes to the tested T-shirt for all apparatuses; and 3) same arc gap (distance between arc electrodes) except the arc in a box. A strong dependence of the ignition threshold on the electromagnetics was demonstrated by the tests. The T-shirt ignition for the ejected arc demonstrated a longer arc flash boundary distance than that calculated by NFPA 70E or IEEE 1584 calculations, raising a need for strong caution in using non-fire retardant (FR) cotton in arc flash conditions. It is suggested that the electrode configuration should be considered in risk analysis. Reported test results could provide a framework in developing arc flash boundary for ejected arc applications. It is shown that, unlike most cases where the IEEE 1584 calculations and NFPA 70E tables were observed to be conservative, in the ejected arc, calculation results should be used with caution as they are less than conservative.