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Highlights • We performed a validity test of the Renal Graded Prognostic Assessment. • Therefore, we developed a new grading index. These results were validated using another dataset including 397 renal cancer patients with BMs. • This new grading system was clearly useful for predicting post-SRS outcomes of BM patients with renal cancer., Background and purpose The Renal Graded Prognostic Assessment (GPA) is relatively new and has not been sufficiently validated using a different dataset. We thus developed a new grading index, the Renal Brain Metastasis Score (Renal-BMS). Materials and methods Using our dataset including 262 renal cancer patients with brain metastases (BMs) undergoing stereotactic radiosurgery (SRS) (test series), we validity tested the Renal-GPA. Next, we applied clinical factor-survival analysis to the test series and thereby developed the Renal-BMS. This system was then validated using another series of 352 patients independently undergoing SRS at nine gamma knife facilities in Japan (verification series). Results Using the test series, with the Renal-GPA, 95% confidence intervals (CIs) of the post-SRS median survival times (MSTs) overlapped between pairs of neighboring subgroups. Among various pre-SRS clinical factors of the test series, six were highly associated with overall survival. Therefore, we assigned scores for six factors, i.e., “KPS ≥ 80%/

The application of Al or Si as antioxidants in MgO-C refractories leads to the in situ formation of new phases. Due to uncertainties regarding phase formation in some references four different test series were heat treated from 800 to 1600 °C under reducing conditions in 200 °C steps. The antioxidant systems investigated were pure Al, Al and Si in two different ratios and SiC. The addition of SiC did not lead to the formation of new phases but in case of Al and Si addition carbides, nitrides, oxycarbonitrides and oxynitrides were formed. The reaction series, its reason and its relation to equilibrium phase composition have been revealed.

The Guardian Cap NXT (GC NXT) and the ProTech Helmet Cap (ProTech) are commercially available aftermarket products designed to augment the energy attenuation characteristics of American football helmets. The ability of these helmet shell add-on products to mitigate the severity of impacts typically experienced by professional offensive and defensive linemen was evaluated for seven helmet models using two test series. In linear impactor tests, the GC NXT reduced head impact severity as measured by the head acceleration response metric (HARM) by 9% relative to the helmets only, while the ProTech reduced HARM by 5%. While both products significantly improved the performance of the football helmets tested overall, effects varied by impact condition and helmet model with the add-ons worsening helmet performance in some conditions. The GC NXT had a strong effect size (Cohen’s d = 0.8) whereas the ProTech had a medium effect (Cohen’s d = 0.5). A second study investigated add-on performance for helmet-to-helmet impacts with eccentric impact vectors and resulted in a mixture of increased and decreased HARM when either add-on was placed on one or both helmets. Estimated risk for serious neck injury with add-ons and without differed by less than 4% for these eccentric impacts.

Whole-body PMHS (Post Mortem Human Surrogate) testing was conducted on the Accelerative Loading Fixture (ALF), which is designed to generate floor and seat loading conditions at the level, rate, location, direction, and extent seen in UBB (Underbody Blast). The overarching goal of this research effort was to examine potential differences in the lower extremity response of females and males under UBB conditions. The ALF consists of an occupant platform that is driven upward by the detonation of an explosive charge. The floor plate undergoes plastic deformation. The occupant platform supports two rigid seats for surrogates. Twenty un-embalmed PMHS were tested, including 50th-percentile males, 75th-percentile females, and 5th-percentile females. Two test series were conducted. Series A had a target floor speed of 8 m/s (2-ms time-to-peak) with a target seat speed of 5 m/s (4-ms time-to-peak). Series B had a target floor speed of 20 m/s (2-ms time-to-peak) with a target seat speed of 4 m/s (7-ms time-to-peak). Major damage occurred to the femur, tibia, fibula, talus, and calcaneus. Lower extremity damage type, incidence, and extent varied between the two sexes. Fifty-percent probability of calcaneus fracture for less than 3-ms time-to-peak is associated with a 781-g peak tibia vertical acceleration for 50th-percentile males, 650-g for 75th-percentile females, and 396-g for 5th-percentile females. Fifty-percent probability of calcaneus fracture, regardless of time-to-peak, is associated with a 368-g peak femur vertical acceleration for 50th-percentile males, 332-g for 75th-percentile females, and 218-g for 5th-percentile females. These results show differences in kinematics and damage outcome between female and male PMHS in UBB conditions. These findings will inform future decisions regarding the requirements for test capabilities that incorporate the female Warfighter. Ultimately, advancements can be made in injury assessment tools such as improved physical surrogates, injury assessment and prediction criteria, modeling and simulation capabilities, test methods, and the optimization of military ground vehicles, personal protective equipment, and injury countermeasures.

This study contributes to the Collaborative Computational Project in Wave–Structure Interaction blind test series 2 by numerically investigating the dynamic response of two simplified point absorber wave energy converters (WECs – a hemispherical-bottom cylinder and a cylinder with moon-pool) under the action of focused waves of varying steepness. The open source toolbox OpenFOAM along with its new overset grid functionality is applied and evaluated for the complex flow problem involving both large free surface deformations and large-amplitude motions of floating objects. The quality of the numerically generated focused wave groups is first examined and validated against the experimental data. The effects of both wave steepness and the moon-pool on the dynamic responses and mooring loads of the simplified WECs are then analysed.

To prevent coal dust explosion propagations, rock dust needs to be lifted and suspended in the air with the coal dust during an explosion. The addition of anti-caking agents prevents caking of rock dust in the presence of water. Mining and rock dusting processes can frequently create alternating layers of rock dust and float coal dust on mine surfaces. For this test series, a thin layer of coal dust was distributed on top of a layer of either treated or non-treated rock dust in the Experimental Mine Barbara, Poland. The experimental results compare the effectiveness of treated and non-treated rock dusts to attenuate a propagating coal dust explosion initiated with either strong or weak methane explosions. Experimental results indicate that the treated rock dust performs better than non-treated rock dust in arresting a propagating explosion, especially in the presence of moisture.

Structural PET foam has a plethora of industry applications, such as inlays for wind turbine blades. However relevant material properties, especially mechanical characteristics, vary significantly between foam types. With new foam compositions being continuously developed by leading vendors, there naturally is limited empirical data in literature on optimal milling parameters for these novel foams. To investigate the milling behavior, raw machine tool data was collected for a test series. Using these data, several distinct process features were calculated. The features were then used to evaluate the performance of several machine learning algorithms in regard to their predictive accuracy.

In the course of this study, several test series were carried out to investigate the triboelectrostatic charging behaviour of various oxides. At the beginning, the influence of the degree of aging and the influence of the sample storage on the charging efficiency of the oxide samples was analysed. For this purpose, two oxide samples were stored under different environmental conditions and then sorted using triboelectrostatic belt separation. Results of a previous series of tests showed that an increased feed temperature has a negative effect on the charging behaviour of calcium and magnesium oxide. Therefore, the effects of a reduced feed temperature were also examined. For these experiments, samples were stored at 8 °C under exclusion of air. In addition, a series of tests was carried out with a gradual increase of the voltage on the triboelectrostatic belt separator in order to determine possible differences in the charging efficiency of calcium oxide and magnesium oxide and to subsequently use them for the separation.

Previous studies indicate that seatbelts may require supplementary restraints to increase their effectiveness in far-side impacts. This study aimed to evaluate the effectiveness of a novel, far-side-specific airbag in restraining and preventing injuries in far-side impacts, and to evaluate the WorldSID’s response to the presence of a far-side airbag. A series of tests with three Post-Mortem Human Subjects and the WorldSID was conducted in a vehicle-based sled environment equipped with a far-side airbag. Results of these tests were evaluated and compared to a previous test series conducted without the airbag. All of the PMHS retained the shoulder belt on the shoulder. The airbag significantly reduced PMHS injury severity and maximum lateral head excursion. While the WorldSID exhibited a similar decrease in lateral excursion, it was unable to represent PMHS thoracic deflection or injury probability, and it consistently slipped out of the shoulder belt. This indicates that the WorldSID is limited both in its ability to evaluate the effect of changes in the seatbelt system and in its ability to predict thoracic injury risk and assess airbag-related injury mitigation countermeasures.

This article examines the use of fiber Bragg grating sensors for cure monitoring purposes in resin transfer molding processes. Within a resin transfer molding test series a thermoset epoxy-amine resin system was used in combination with a woven flax fiber reinforcement. Particular attention was paid on the location of the optical fiber sensor and its sensitive Bragg grating element inside the mold cavity. Three different installation approaches were tested and the correlation of the corresponding strain response with the actual cure state of the resin system was investigated at 50°C and 70°C isothermal cure temperature, respectively. We could demonstrate that characteristic, conspicuous strain changes are directly related to the sol–gel conversion of the thermoset polymer, which was analyzed considering different approaches for the gel-point detection based on rheological measurements. With the installation of the sensor inside a controllable, capsuled resin volume, we could achieve the most reliable strain response that provides capabilities to give in-situ information of the cure state beyond the gelation point.

The purpose of this parameter test is to equip persik trainers with themselves and their staff in order to know the physical condition of the U-20 persik kediri athlete so that the training program can be on target. In addition, the parameter test is also used to evaluate the progress of training towards achievement in each match. This parameter test also has the benefit of setting methods for preparing parameter tests and compiling test guidelines, or SOP so that parameter tests carried out in the field have valid and reliable test prerequisites, and have the same interpretation throughout Indonesia, especially in the Football Sports Branch . For the method here, it uses the field practice method through the persik kediri athlete U-20 to carry out a series of parameter tests in soccer Athletes are asked to carry out the test series in accordance with SOPs that have been determined. The results of this parameter test are that the persik kediri athlete U-20 has physical conditions in categories or good norms in each form of test that is directed at the physical condition of soccer athletes

The detection of accident scenarios is essential for a timely deployment of restraint devices and therefore for optimum protection of the vehicle occupants. Based on an innovative concept for crash detection, which involves measuring component-related local decelerations, this paper presents an entirely new method for the simulation and evaluation and estimates this with of a comprehensive set of crash load cases. With this approach, decelerations are detected directly at numerous individual components in the vehicle front end and are integrated in a velocity reduction using small time intervals. An evaluation based on multivariate statistical methods shows that the information content which results from exceedance of one defined velocity reduction threshold per measuring point is sufficient to safely distinguish between and classify all relevant load cases with a high level of independence. The concept has therefore proven to be functional and will be transferred to initial test series.

The application of pelvic binders in the preclinical and early clinical phase is advisable to avoid or treat C-problems in unstable and potential bleeding pelvic ring fractures, even if the clinical effectivity is not completely proved. The use for pathologies in the posterior pelvic ring is still debatable. We determined if there is a difference in achievable compression in the dorsal pelvic ring depending on position and pelvic binder model. Can this effect be tested with a simplified artificial model? We simulated a Tile type C fracture within the established pelvic emergency trainer and measured in a test series the effectivity of reduction with a non-invasive stabilization technique using 3 different pelvic binders. Any therapeutic effect of a pelvic binder with compression to the posterior pelvic ring requires at first a reduction maneuver. While the compression effect in the symphysis depends only on positioning of the binder, in the posterior pelvic ring, the result varies with the used model. The achievable pressure in the SI joint with a pelvic binder is only 20–25% (33.5–47 N) compared to the C-Clamp values (156 N). The use of pelvic binders for non-invasive pelvic ring stabilization, even with a posterior pathology, could be proven in a simplified fracture model. A proper fracture reduction and an adequate device positioning influence the effectiveness. The use of an emergency pelvic trainer even for a non-invasive maneuver is advisable.

Background Nickel is a ubiquitous element used in many everyday items. In recent decades nickel has become a leading allergen, which has become a public health problem. Objective To evaluate frequently used nickel products in Brazil. We investigated if these objects release nickel that is capable of inducing sensitization or cause clinical manifestations in terms of allergic contact dermatitis (ACD). Methods Dimethylglyoxime (DMG) spot tests assessed nickel release from several common utensils used in everyday life in Sao Paulo and Rio de Janeiro, Brazil. Results We tested 46 coins (two denominations) and 90 common utensils. Approximately 91.1% produced nickel-positive results using the DMG spot test. Conclusions The DMG limit of detection was 1.67 ppm of nickel. We observed that many objects in our test series released nickel above the DMG test limit. This observation suggests that nickel-sensitive individuals may be exposed to nickel, representing a public health issue.

Purpose: To (1) compare the power output (PO) for both the 20-minute functional threshold power (FTP20) field test and the calculated 95% (FTP95%) with PO at maximal lactate steady state (MLSS) and (2) evaluate the sensitivity of FTP95% and MLSS to training-induced changes. Methods: Eighteen participants (12 males: 37 [6] y and 6 females: 28 [6] y) performed a ramp-incremental cycling test to exhaustion, 2 to 3 constant-load MLSS trials, and an FTP20 test. A total of 10 participants returned to repeat the test series after 7 months of training. Results: The PO at FTP20 and FTP95% was greater than that at MLSS (P = .00), with the PO at MLSS representing 88.5% (4.8%) and 93.1% (5.1%) of FTP and FTP95%, respectively. MLSS was greater at POST compared with PRE training (12 [8] W) (P = .002). No increase was observed in mean PO at FTP20 and FTP95% (P = .75). Conclusions: The results indicate that the PO at FTP95% is different to MLSS, and that changes in the PO at MLSS after training were not reflected by FTP95%. Even when using an adjusted percentage (ie, 88% rather than 95% of FTP20), the large variability in the data is such that it would not be advisable to use this as a representation of MLSS.

During the development and optimisation of wave energy converters, numerical wave tanks are useful tools, providing detailed insight into the hydrodynamic performance of devices. Specifically, computational fluid dynamics (CFD)-based numerical wave tanks (CNWTs) can deliver high-fidelity, high-resolution results for a wide range of test conditions. However, CNWTs come at significant computational cost and require more man-hours during model setup, compared to lower-fidelity, frequency domain-based models. The computational costs can only be significantly decreased by improving the numerical solvers or by increasing expenditure on computational power. The required man-hours for the model setup, however, can be reduced by streamlining the setup of CNWTs. To this end, the formulation of best-practice guidelines can expedite this streamlining. A step toward such best-practice guidelines is blind tests. This paper presents the CNWT used for the authors’ contribution to the Collaborative Computational Project in Wave–Structure Interaction (CCP-WSI) Blind Test Series 3. In the employed numerical wave tanks, a self-calibrating impulse source wave maker is implemented for wave generation. In addition to the numerical results, and the comparison with the recently disclosed experimental data, the paper presents the spatial and temporal convergence studies, as well as results for the numerical wave maker calibration. The numerical results show average deviations with the experimental data of less than 10%. Furthermore, a correlation between the accuracy of the numerical replication of the wave and the agreement between numerical and experimental device motion is highlighted.

When coating and repairing operations demand the deposition of stainless steel material, the Cold Spray (CS) device needs to be run in high-pressure gas conditions requiring complex and heavy system architecture. The processing condition together with the system setup make prohibitive the adoption of high-pressure CS for in-situ operations. The design of a new CS solution for reaching the deposition of stainless steel alloy with low-pressure gas condition together with transportable-wise system for in-situ operation is presented. The performance of the proposed solution is validated with a test series and the results compared with the State of the Art (SoA).

53rd CIRP Conference on Manufacturing Systems 2020, CIRP CMS 2020, onlne, 1 Jul 2020 - 3 Jul 2020; Procedia CIRP 93, 20-25 (2020). doi:10.1016/j.procir.2020.04.013 special issue: "53rd CIRP Conference on Manufacturing Systems 2020 : 53rd CIRP Conference on Manufacturing Systems / Edited by Robert X. Gao, Kornel Ehmann", Published by Elsevier, Amsterdam [u.a.]

Experiments on bentonite slurry infiltration into saturated sand have been carried out in a modified laboratory set-up that provides a hydraulic gradient comparable to real tunnels. Test series 1 investigated the characteristics of mud spurt and filter cake formation during water–bentonite slurry infiltration, before and after removing the external filter cake formed on the original boundary between the slurry and the sand. Test series 2 examined the conditions of filter cake formation during water–bentonite–sand slurry infiltration. The experimental results of series 1 indicate that, in the second infiltration, a new external filter cake will be formed for low concentrations of slurries (40 and 50 g/l), whereas hardly any new external filter cake formed for high concentration of slurry (60 g/l) owing to the formation of an internal filter cake in the sand during the first infiltration. The formation of this internal filter cake meant that the infiltration distance was much smaller for the second infiltration than that in the first for 60 g/l slurry. The experimental results of series 2 with a water–bentonite–sand slurry showed no external filter cake formation, but depth filtration was observed for high-density slurry (1300 and 1500 kg/m3). For low-density slurries (1050 and 1100 kg/m3), a thicker external filter cake, but with a higher permeability, than that in series 1 was observed on the sand surface, because the cake consisted to a large extent of sand particles. Mechanisms of mud spurt and filter cake formation are discussed, with a new solution for mud spurt and the theory of depth filtration.

Steadily increasing traffic volumes and traffic loads lead to a continuously growing demand for bridge rehabilitation, strengthening and replacement projects. For existing steel girder bridges with non-composite concrete decks, the traffic load capacity can often be increased significantly if composite action can be created afterwards. Different kinds of shear connectors are more or less suitable for post-installation. Coiled spring pins are one type of interference fit connector that can be installed from below the bridge deck during traffic, in order to minimize the impact on road users. This paper describes an experimental study on the static capacity and stiffness of coiled spring pins used as shear connectors at steel-concrete interfaces. Six push-out test series are presented, with a total of 28 tests, together with an alternative type of test set-up. The results show that the failure of the coiled spring pins is very ductile and that the load capacity is predictable and sufficient for a cost-effective application. The tests also indicate a significantly lower stiffness of the connectors in comparison to welded headed studs of similar dimensions, which might be of great importance if an existing shear connection is strengthened.

BACKGROUND Cases of allergic contact dermatitis (ACD) caused by isobornyl acrylate (IBOA) in the Omnipod® insulin pump have previously been reported. OBJECTIVES To present three cases of patients with ACD caused by a new allergen in the pump, and results from chemical analyses. METHODS Omnipod pumps from different batches were analysed by gas chromatography-mass spectrometry. Aimed testing, with the department's medical device (MD) series and substances identified in the pump including dipropylene glycol diacrylate (DPGDA) at 0·01% and 0·1% in petrolatum (pet.), was performed. Patch testing also included extracts from the device, the adhesive patch as is, and allergens from baseline series. RESULTS All patients tested positive to 0·1% DPGDA in pet., and two patients additionally to a 0·01% concentration. DPGDA was found in extracts of the Omnipod pumps brought by the patients. An Omnipod pump from an earlier batch contained tripropylene glycol diacrylate, IBOA, N,N-dimethylacrylamide, di(ethylene glycol)ethyl ether acrylate (DEGEA) but no DPGDA. One of the patients reacted positively to all of these allergens except DEGEA, which was not tested. CONCLUSIONS When suspecting ACD to MDs, DPGDA at 0·1% in pet. should be tested. The contents of Omnipod have changed over time. Patch testing with updated test series and relevance assessment of positive reactions is a delicate task. Children, with lifelong use of MDs, risk contracting many allergies with potential cross-allergies. A question should be raised as to whether these low molecular weight acrylates should be used at all in devices constantly worn on the skin.

Equations for calculating evapotranspiration in technical soils show great differences regarding their results. Causes are the different climatic conditions and vegetation specifics during their development. Every equation of evapotranspiration only delivers 100% correct results if it is used under the same climatic condition as it was developed in. To determine the evapotranspiration, the loss of weight of different technical soils and plants was measured in a test series on load cells in a climate chamber. The result of these test series is the development of an easy-to-use equation. An equation for calculating evapotranspiration at any temperature is possible while using a polynomial correlation. To determine the evapotranspiration rate (in mm/m² per 24 h), only temperature, vegetation type, and technical soil have to be defined to obtain an output of evapotranspiration in mm/day. Using the well-known equation by Makkink, evapotranspiration in technical soils is 0.12 mm/day, whereas the newly developed equation calculates (1) 2.59–5.58 mm/day for the variant with no vegetation, (2) 3.15–4.00 mm/day for Sedum floriferum, (3) 4.40–4.55 mm/day for Geranium x cantabrigiense. The application of this equation will help to determine the evapotranspiration in chosen technical soils (used in the sector of rainwater management) with or without vegetation.

The fatigue limits of shafts and shaft-hub connections are subject to a probability distribution. This distribution can be described by the mean value and the scatter of the fatigue limit. The mean fatigue limit can be determined with very few samples, whereas the scatter cannot be determined precisely. In order to develop a reliable design of shafts and shaft-hub connections, it is certainly necessary to know the scatter of the fatigue limit. Parameters that may influence the scatter are investigated on the basis of evaluated test series from literature, for shafts with failure at the free surface and shaft-hub connections. The analysis focuses on the type of load, the highly stressed surface or the shaft-hub connection type. A calculation method for determining the fatigue limit for a given survival probability will be presented.

At the French-German Research Institute (ISL), several railgun setups are used to investigate different military scenarios. One compelling scenario for a railgun application is the long-range artillery. For this, it is required to be able to handle multimegaampere currents to accelerate heavy launch packages of velocities above 2 km/s and to do so as efficient as possible. The NGL-60 is a 6-m-long open-barrel breech-fed railgun with a square caliber of 60 mm. With this railgun, it will be possible to fully utilize the currently available 10-MJ capacitor-based power supply unit (PSU). To validate the concept of the NGL-60 design, a 2-m-long prototype was installed. Subsequent tests showed that the railgun design is able to handle currents above 2 MA without structural damages or electrical failures. After the successful test series with the prototype, the construction of the full NGL-60 started and is finished by now. In this report, results from the prototype tests are reported, and the first experiments with the 6-m-long NGL-60 are presented.

This paper describes a second stage of a comprehensive experimental study of the fragment damage effect on the mechanical properties of reinforced concrete (RC) elements. In the first stage, RC elements were exposed to fragmentation impact in a field test series. These specimens were then brought to the laboratory together with reference undamaged specimens, to experimentally study their structural behavior in three-point bending static tests. All specimens exhibited a flexural failure mode and the characteristics of the resulting load-deflection curves are presented and analyzed. The effects of the fragmentation impact from the preceding field tests show differences between the behavior of the undamaged and damaged specimens with respect to their flexural moment capacity, stiffness, deflection capacity and structural ductility. Additionally, evaluation of an equivalent cross-section height is presented, which enables flexural analysis of RC elements under a combined loading of blast and fragments, in cases where the fragments reach the element before the blast (or at the same time). The quantitative results that have been obtained in this study emphasize the importance of considering the damage due to the fragmentation impact, which cannot be neglected, at least within a certain standoff distance.

This paper describes an experimental investigation on a pair of spur gears in which wear and pitting were intentionally allowed to occur, namely, moisture corrosion pitting, acid-induced corrosion pitting, hard contaminant-related pitting and mechanical induced wear. A back to back spur gear test rig was used throughout 32 test series. The tests samples of wear debris were collected and assessed through the utilization of an optical microscope in order to correlate and compare the debris morphology to pitting and wear degradation of the worn gears. In addition, weight loss from all test gear pairs were assessed with utilization of statistical design. It was observed that there were significant distinctions between both weight losses, wear debris morphology generated from each induced pitting conditions and worn surface characteristics. It can be deduced that wear debris characteristics exhibited a direct relationship with different pitting and wear modes. Thus, it should be possible to detect and diagnose gear pitting and wear utilization of worn surfaces, generated wear debris and quantitative measurement such as weight loss.

The paper presents the detailed test setup and results of a test series on bolted single steel angles in compression with varying end support conditions and slenderness ratios. For all tests FEM-calculations were done, which are also presented. In total 27 specimens with one-bolt and two-bolt connections with and without preload are tested. Three different boundary conditions on both ends are investigated: Boundary condition 1 (BC1) is a clamped support. BC2 is a knife edge support that allows only for rotations about the axis parallel to the connected leg. BC3 is a fully hinged support. In addition to the results of the member tests, imperfection measurements and results of material tests are presented in order to carry out the FEM-calculations and to allow for comparison with current design standards.

An important characteristic of self-healing concrete is its ability to regain liquid tightness after it has been damaged. This ability can be tested using water permeability setups. However, a lack of standardized test methods makes it difficult to compare results between different studies. Additionally, the large variation on crack widths between specimens results in a large spread of the permeability results. This, together with all other factors (e.g. internal crack geometry) contributing to the variability of permeability results, should be clearly assessed in order to develop a standardized permeability test. In this study a new active crack width control technique has been developed to significantly reduce the variation on the crack width within a series of specimens, resulting in more consistent permeability results. By analysing permeability results of specimens from test series with different nominal crack widths the factors contributing to variability could be assessed. The two main contributors are the variability on the mean crack width at the crack mouth and the variability on the internal crack geometry. The variability of the mean crack width can induce a 3 times higher variability of the permeability results. In contrast to the crack width, the internal geometry of a crack cannot be determined directly, yet it can cause a difference in permeability of more than 25% for specimens with an identical nominal surface crack width. It can be concluded that when crack widths are actively controlled, the main source of variability on permeability results is the internal geometry which cannot be controlled, regardless of the chosen cracking technique. In order to reduce the variance on the mean permeability, it is proposed to use at least six specimens per series.

Self-tapping screws are fasteners that are versatilely applicable in timber engineering. For the design of such screw connections, preferential axial-loading, all possible failure mechanisms have to be considered. Recently, in compact groups of axially-loaded screws the block shear failure mechanism, which has not been investigated so far, turned out to fail rather brittle at load levels lower than currently allowed. This failure mechanism is defined as failure of (rolling) shear and/or tension perpendicular to grain planes encompassing the group of screws. This failure mechanism was observed in groups given a number of different parameter settings, i.e. thread-fibre angles of 90° and 45°, glulam, structural timber and cross laminated timber and various group designs. This paper focuses on groups of axially-loaded screws in glulam and solid timber of Norway spruce (Picea abies) and inserted at a thread-fibre angle of 90°. Varying group sizes, loading and supporting distances and group designs, i.e. various penetration lengths lef and spacing in and perpendicular to grain, a1 and a2, respectively, are analysed by two different “push-pull”-test setups. To predict the block shear capacity and failure characteristics of such groups of screws and to separate this failure mechanism from other failure mechanisms, a mechanical-based block shear model was established. This parallel acting spring model considers load sharing and redistribution between concerned failure planes and depends on a number of material, geometrical and stress distribution parameters. To ensure a reasonable parameter setting, background and potential influencing parameters on each model parameter are discussed. In validation, the model shows overall good predictions of capacities, failure mechanisms and failure sequence for all test series involved. It turned out that the current regulations, comprising the definition of minimum spacing together with minimum edge and end distances, are not sufficient for controlling this three-dimensional block shear failure. In addition, the consideration of the number of screws in the group as well as the penetration length is required.

Monotonic and cyclic direct simple shear tests with shear wave velocity measurements were conducted on a series of silica sand gradations to examine the effect of both fines content and grain size distribution. Two test series were considered, one with parallel gradations with decreasing D50 and constant Cc, Cu values (N-series), and a second one where Cc was kept constant and Cu, D50 values varied (W-series). In both series, the fines content varied from 0 to 50%. The most dramatic effects were noted for the clean sands as the Cu value increased and for the silty sands as fines content increased from 1 to 50%. In general, static and dynamic behavior was observed to depend on the amount of fines, Cu and D50 values. The same was true for pre-cycling and post liquefaction shear wave velocities. Post-liquefaction shear wave velocities were on the order of 8–13% of the pre-cycling values.

BACKGROUND AND PURPOSE: MR imaging rescans and recalls can create large hospital revenue loss. The purpose of this study was to develop a fast, automated method for assessing rescan need in motion-corrupted brain series. MATERIALS AND METHODS: A deep learning–based approach was developed, outputting a probability for a series to be clinically useful. Comparison of this per-series probability with a threshold, which can depend on scan indication and reading radiologist, determines whether a series needs to be rescanned. The deep learning classification performance was compared with that of 4 technologists and 5 radiologists in 49 test series with low and moderate motion artifacts. These series were assumed to be scanned for 2 scan indications: screening for multiple sclerosis and stroke. RESULTS: The image-quality rating was found to be scan indication– and reading radiologist–dependent. Of the 49 test datasets, technologists created a mean ratio of rescans/recalls of (4.7 ± 5.1)/(9.5 ± 6.8) for MS and (8.6 ± 7.7)/(1.6 ± 1.9) for stroke. With thresholds adapted for scan indication and reading radiologist, deep learning created a rescan/recall ratio of (7.3 ± 2.2)/(3.2 ± 2.5) for MS, and (3.6 ± 1.5)/(2.8 ± 1.6) for stroke. Due to the large variability in the technologists9 assessments, it was only the decrease in the recall rate for MS, for which the deep learning algorithm was trained, that was statistically significant (P = .03). CONCLUSIONS: Fast, automated deep learning–based image-quality rating can decrease rescan and recall rates, while rendering them technologist-independent. It was estimated that decreasing rescans and recalls from the technologists9 values to the values of deep learning could save hospitals $24,000/scanner/year.

The innovative RPM-Synchronous Grinding process enables highly efficient manufacturing of various geometries in an ordinary plunge grinding process. An oscillation of the infeed axis, which is coupled to the rotary workpiece spindle axis, like in conventional non-circular grinding approaches is not required. This is achieved by using a fixed ratio of grinding wheel- and workpiece speed and also a non-circular grinding wheel geometry. In this first test series, practice-orientated circular steel-workpieces are Synchro-Finish ground with conventional vitrified grinding wheels for finishing applications. The surface topography of the Synchro-Finished parts is evaluated and compared with conventionally ground workpieces.

The primary function of shaft-hub connections is the transmitting of torsional moments. The polygon-shaft-hub connection is a type of shaft-hub connection with increasing importance. Compared to conventional press fits, a main advantage of this type of connection is the additional normal force in the contact joint due to the eccentricity of the polygonal profile. This results in the possibility of transmitting high static torsional moments. These static torsional moments often occur with rotating bending. Due to this aspect, the combined load case is of particular importance for the durability of shaft-hub connections. Therefore, the currently unknown static load capacity and high cycle fatigue strength of polygon-shaft-hub connections were investigated in this paper. Part of the investigations were polygon-shaft-hub connections with a hypotrochoidal profile shape manufactured from the materials C45E or 42CrMo4. The static tests aimed at evaluating the transmissible torsional moment up to the point of permanent deformation. The different test series in the field of fatigue strength were evaluated under rotating bending or rotating bending with static torsion as mean stress. Based on the evaluated fatigue strengths, notch factors were calculated. Using the notch factors, an approach for a calculation method for the fatigue strengths of polygon-shaft-hub connections was developed.

An experimental study was performed to determine the influence of centre bow length and tunnel height on the magnitude of the wave slamming loads and bending moments acting on a 112 m Incat wave-piercer catamaran vessel. A 2.5 m hydroelastic segmented catamaran model was tested in regular head sea waves at a high model speed in multiple test series, whilst five centre bow (CB) and wet-deck configurations were considered, designated here as the parent, low, high, long and short CBs. The model global motions, centre bow slam loads, accelerations, and slam induced vertical bending moments of the catamaran model in waves were measured. It was found that the slamming force, the centre bow entry force and slam induced bending moment all increase as the centre bow length increases. Increasing the wet-deck height increased the motions but reduced the maximum slam load in moderate waves. It was seen that the short CB was the best design for the alleviation of slam loads. The high CB was the second best choice for operation in moderate waves but it was the worst configuration in terms of heave and pitch motions among various CB configurations tested.

The Part II of this two-part paper evaluates the results of the experimental test series introduced in Part I. This research aimed to examine the major influencing parameters of stressed skin effect in industrially applied, nonstandard diaphragm configurations. As no international study was executed in state of art, in order to study the role of different variables to shear flexibility, a full-scale test series was executed at the Budapest University of Technology and Economics, Structural Engineering Department. In Part I the experimental test arrangement and shear flexibility results are introduced in comparison with the results derived from the ECCS formulae. This paper, denoted as Part II details the evaluation of full-scale test results by underlining conclusions regarding the effect of change in section size of structural components and the number of fixings, and the effect of variation in structural arrangements. The results of this investigation shows that in nonstandard cases the stiffening effect of diaphragms are comparable to the stiffening effect of bracing.

Shear strength is one of the most widely investigated parameter in reinforced concrete (RC) beams. Numerous papers are published in last 66 years which investigate experimentally and theoretically the shear strength of RC beams without shear reinforcement. In this paper a database on shear strength of 719 RC beams without transverse reinforcement is generated from experimental results published between 1952 and 2018. Well-known shear strength models proposed in the literature are summarized and evaluated through comparison with the experimental results of generated database. It was found that models proposed by Niwa et al. (1986) and Zararis and Papadakis (2001) predicts shear strength of RC beams more accurately than the other models. The former model gives an average strength ratio of 1.05 with a coefficient of variation of 29% while the latter yielded an average strength ratio of 1.10 with a coefficient of variation of 29%. A detailed evaluation in various ranges of parameters revealed that both the models gives unconservative results of shear strength for beams with concrete compressive strength >90 MPa. Parametric study of the two models within the individual test series showed that model of Niwa et al. does not capture the size effect in RC beams very effectively while the model of Zararis and Papadakis yields uniform results over the whole range of experimental data.

Frequency falls in the elderly still a problem that often happens in Indonesiaespecially in the Village of Rumah Great Kec Biru-Biru Kabupaten Deli Serdang. High prevalence rates incident falls in the elderly, which makes researchers want to apply the TUG (Timed Up And Go) test through the amount of time provided and the ability of the elderly complete the test series with the time needed by the elderly themselves. This research aims to knowing Relationship of the TUG Test (Timed Up And Go) with Frequency of falls In the elderly in Rumah Great Kec Biru-Biru Kabupaten Deli Serdang. Where is this TUG test used for knowing balance and disruption of walking in the elderly. Data collection begins from March to June 2017 with a total of 64 respondent by using categorical analytic research and cross sectional approach as a sampling method. Research instrument used in the form of a demographic data questionnaire, a TUG (Timed Up And Go) test questionnaire and a Meter Meter. The results showed that the sign value was 0.002

Two test series were carried out on angle cleat connections between cold-formed channels as beams and rectangular hollow sections as support members. The objective of the tests was to deter...