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A team comprising nursing, medical staff, and administrative leaders at an urban academic orthopedic hospital in the northeastern United States sought to revise a preoperative laboratory testing protocol based on evidence and practice guidelines. The goal was to decrease unnecessary tests by 20% without negatively affecting patient outcomes. After adding the revised protocol to the electronic health record, audits revealed that the target goal was not met and additional strategies were implemented, including educational webinars for surgeon office personnel who ordered tests, additional webinars for advanced practice professionals, and the creation of scorecards to track surgeons' progress. Overall, a downward trend in the ordering of unnecessary laboratory tests for patients without identified risks was observed, but a 20% reduction was not achieved. Surgical complications during the project were not associated with laboratory tests. Clinicians continue to use the revised preoperative laboratory testing protocol at the facility. [ABSTRACT FROM AUTHOR]

Visco‐hypoplastic material model for tertiary soils in Frankfurt am Main The subsoil conditions in the city centre of Frankfurt am Main are characterized by tertiary over‐consolidated clays and clayey marls with embedded limestone banks and sand layers, whose thickness varies considerably depending on the location. In a research project, the time‐dependent material response of these tertiary clays, which significantly influence the deformation behaviour of buildings, was investigated with a comprehensive laboratory test program and a set of parameters for the visco‐hypoplastic AVISA model was determined. This article summarizes the findings obtained for the tertiary Frankfurt clays. In addition, a concept is proposed with which the system permeability and the system stiffness of the heterogeneous tertiary layers taking into account embedded limestone banks and sand layers can be realistically modelled in 3D coupled pore pressure‐displacement analyses with the finite element method. [ABSTRACT FROM AUTHOR]

Comprehensive study of local stresses at transverse stiffeners of crane runway girders based on tests and numerical calculations In practice, welded crane runway girders with greater web heights are usually designed with additional transverse stiffeners between the supports. This increases the buckling resistance of the web and limits the torsion of the top flange due to eccentric wheel load application. However, this creates additional critical design details near the welded connections between top flange and stiffeners with regard to wheel load introduction into the girder web. These details have to be accounted for in the verification against fatigue failure. Furthermore, the current version of DIN EN 1993‐6 does not contain any rules for calculating the local stresses in the web and in the transverse stiffeners for wheel load introduction near transverse stiffeners. This article therefore presents both laboratory tests and FE‐calculations that investigate the local stresses in the vicinity of transverse stiffeners in detail. Subsequently, the determined stresses are used for comparative fatigue design checks at the relevant constructional details in relation to corresponding design checks without taking the influence of the transverse stiffeners into account. Finally, deficits in the current procedure are highlighted and recommendations for design practice are derived on the basis of the results obtained. [ABSTRACT FROM AUTHOR]

This work is part of the European RFCS "FISHWALL" project entitled "Fire and Seismic performances of hybrid fire walls in case of single‐storey industrial and commercial steel buildings". The aim of the project is to design a hybrid firewall solution using sandwich panels for single‐storey buildings connected with the unprotected steel structure by means of fusible links, made of aluminium bolts. In this respect, the paper shows the results of preliminary numerical analyses performed on existing case studies of single‐storey steel buildings located in low and moderate seismicity zones and they were used: i) to estimate the seismic forces acting on the fusible links and ii) to subsequently design the specimens to be tested in the laboratory. In this respect, several finite elements models were developed in order to consider the widest range of configurations of the firewall with respect to the direction of the portal frame composing the steel buildings, i.e. firewall parallel and orthogonal to the portal frames. Based on the estimated forces, the design of the six different specimens was performed and it is thoroughly shown in the paper. [ABSTRACT FROM AUTHOR]

Experiences with the application of the needle penetrometer test in marlstone The correct assessment of Unconfined Compressive Strength represents one of the core tasks in the context of the planning and execution of civil engineering, tunneling and geotechnical engineering works. However, in weak and non‐durable rock types, sampling, preservation of the natural water content, sample preparation and finally testing with standard laboratory testing methods, such as the Uniaxial Compressive Strength test, is challenging, if not impossible. As early as 1980, the needle penetrometer was developed in Japan as a field test method for estimating the Unconfined Compressive Strength of such rocks. Although the procedure is presented in an ISRM Suggested Method published in 2014, the use of the needle penetrometer and the needle penetrometer index (NPI) is rather unusual in Germany and Central Europe. The paper resumes the results of a large number of tests carried out in the course the geotechnical investigation of pile drilling works in marlstones of the Upper Cretaceous in the vicinity of Münster/Germany. Based on this experience, the article presents an analysis of the potential area of application and comments on the correlation of testing results and Unconfined Compressive Strength. [ABSTRACT FROM AUTHOR]

Uniaxial and triaxial compression tests on frozen sands and clays – Influence of saturation and temperature Partial saturation leads to a significant decrease in the short‐ and long‐term strength of frozen sands and gravels so that the stability of the frost body can be impaired in artificial ground freezing applications. Uniaxial and triaxial compression tests with on‐unit cooling were performed on sand to determine uniaxial compressive strength, creep resistance and shear parameters. The results confirm and complete the findings from the few previous studies. Investigations on undisturbed specimens of medium and high plasticity clay using the same testing technique illustrate the influence of the consistency limits and the increase in short‐ and long‐term strength at lower temperatures. [ABSTRACT FROM AUTHOR]

The challenge of soil classification – Possibilities and advantages of the cone penetration test Geotechnical reports, which include the classification of the subsoil, represent the basis for project planning and are often essential for awarding construction services. Various standards, such as the ISO 14688‐1 and the Unified Soil Classification System (USCS), are used in practice to characterize the soil based on its particle size distribution and plasticity. In contrast, indirect classifications by means of cone penetration tests are based on soil behaviour type charts. In this paper, classification systems based on the physical properties of soils (ISO 14688‐1, USCS) and in‐situ tests are compared at different test and construction sites. The results indicate that soil behaviour type charts according to Robertson (2009, 2016) and Schneider et al. (2008) are suitable for estimating particle size distributions in alpine deposits, even though a better agreement is reached in fine‐grained soils with the USCS, compared to the ISO 14688‐1. Alternative classifications were elaborated for these soil behavior type charts, leading to an improved estimation of the particle size distribution. Further results illustrate that the estimation of particle size distribution by geotechnical engineers requires great experience in fine‐grained soils and can vary significantly. [ABSTRACT FROM AUTHOR]

The present study evaluates the structural and environmental performance of recycled fibers as a low‐cost and eco‐friendly reinforcement of segmental tunnel lining. In this research, the defect effects in the support area are investigated using three types of scaled panel samples. In addition to the fiber‐only reinforced concrete, the performance of a new hybrid design is evaluated. The axial displacements, crack widths, crack lengths, and crack depths were monitored by displacement gauges and image processing. The experimental and numerical results show that the presence of defects, in addition to increasing at least five times the opening of the spalling crack, induces the appearance of new secondary cracks. Based on the results, it was observed that recycled fibers have a good ability to reduce the opening and growth of cracks. The hybrid reinforced design showed a significant performance compared to conventional reinforced segments, even in the most critical support conditions. According to several environmental parameters, the highest environmental compatibility in continuous support conditions is related to the fiber‐only reinforced concrete design; however, with presence of defects in the support area, the new hybrid reinforced design has shown the highest environmental compatibility in most environmental parameters. It was finally concluded that the fiber‐only reinforced concrete with recycled steel fibers and the new proposed hybrid reinforced concrete designs had high efficiencies in all cases in terms of structural, environmental, and economical performances. In addition to significantly reducing the crack openings in the hybrid reinforced design, the used rebars were reduced by about 40%. [ABSTRACT FROM AUTHOR]

Influence of humic substances on the strength of binder‐improved organic soils Organogenic and organic soils are often classified as having a low bearing capacity and therefore mostly do not meet the requirements on civil engineering use for common geotechnical structures. Soil stabilization methods make it possible to increase the strength and stiffness of soft soils, e.g. by mixing binders into the soil matrix and thus, achieve the important societal goals of resource conservation and waste avoidance. However, the processes involved in cement hydration under the presence of organic components are very complex and multivariate. In particular, the soluble fraction of humic substances in the organic material can lead to the target design strength not being achieved. In order to investigate the influence of humic substances, in particular humic acids, on the strength‐determining cement hydration, the objective of the present study was to quantify the humic fractions of different organic soils in order to asses processes involved in the setting process during subsequent strength testing. In addition, a color scale was developed for the qualitative determination of humic acids, which is proposed for use in practice. The analysis of the humic fractions is based on their extraction and subsequent determination by UV/VIS spectroscopy using calibration standards. The subsequent testing of the unconfined compressive strength is based on binder‐improved sand samples, to which organic material was added in different proportions. It is shown that not only the choice of the binder nor the proportion of the organic admixtures, but in particular the composition of the organic material has an influence on the stabilization potential of organogenic and organic soils. [ABSTRACT FROM AUTHOR]

Influence of density on suffusion behaviour of binary granular packings Suffosion is a hydromechanical process that describes a rearrangement and transport of fine particles in soil as a result of water flow. In order to understand the effects of material loss due to suffosion on material behaviour, the influence of density on the mass of material loss, volumetric deformation and the change in permeability was investigated. For this purpose, the structure (contact and contact force distribution) of a soil susceptible to suffosion was qualitatively simulated and analysed with help of DEM. The effects of different densities were investigated experimentally by means of laboratory tests under isotropic load and constant flow. A decrease in material loss, a decrease in deformation and a decrease in permeability due to suffosion with increasing material density were found. In order to be able to describe the change in mechanical behaviour, drained triaxial tests were carried out on non‐eroded and eroded samples, respectively. It was shown that the drained shear strength mainly depends on the void ratio of the coarse material before shearing, regardless of whether this was created artificially or as a result of flow. [ABSTRACT FROM AUTHOR]

Failure criteria for foam‐grouted gravel under multiaxial loading Foam grouting is an innovative method for improving the mechanical properties of cohesionless, coarse‐grained soils. Despite this, only a few experimental studies have been conducted to assess the failure of foam‐injected soils under multiaxial loading. This paper aims to fill this gap in knowledge. The stiffness and strength of the natural soil, which serve as reference values for the evaluation of the improvement effect due to the injection, are derived from drained triaxial tests. The mechanical behaviour of the foam‐injected soil is investigated using uniaxial, triaxial, and splitting tensile tests. The foam‐injected soil, exhibits significantly higher strength and stiffness but lower ductility than the untreated soil. The ductility of the foam‐injected soil increases with increasing lateral pressure. The splitting tensile strength is only a small fraction of the compressive strength. The adequacy of the failure criteria Mohr‐Coulomb, Hoek‐Brown and Lade for the description of the failure of foam‐injected coarse‐grained soils is verified. All three failure criteria are basically suitable to describe the state of failure in triaxial compression. For compressive and tensile loading, the Hoek‐Brown and Lade failure criteria seem to be more appropriate compared to Mohr‐Coulomb. [ABSTRACT FROM AUTHOR]

Investigations of cell construction and evaluation of monotonic simple shear test with sand The simple shear test is a sophisticated laboratory test which has been used in several studies to investigate static and cyclic soil behaviour. Despite the wide range of possible utilization, the simple shear test is not commonly used and there is no European or German standardization for these types of test. In this article, the requirements for the boundary conditions of a simple shear test are defined and the theoretical principles for determining the stress state are presented. For this purpose, the different types of devices for simple shear tests are shown and discussed. In order to evaluate the influence of the boundary conditions, monotonic tests with sand are carried out on a device with different cell constructions. The PIV method is used to study specimen deformation. Based on the test results, various boundary conditions and their influences are shown and discussed. Furthermore, these results can be used as references for the interpretation of the simple shear tests. [ABSTRACT FROM AUTHOR]

At the Water Engineering Laboratory of the University of Perugia, Italy, a wide experimental program has been carried out in a polymeric pipe network with two 100 × 100 m square loops. The aim of this program is to analyze the dynamic response of the system to transients caused by a change in water consumption. To emphasize such a response, transients are generated by the complete and fast closure of an end‐user, located at the downstream end of a service line. During tests, the combined effect of simultaneous consumers, whose consumption is varied both deterministically and stochastically, has been analyzed. The tests allow examining the propagation of the generated pressure waves within the network for different water consumption variations and end‐user locations. The lessons learnt from the experimental results may help the water utility managers to identify the reasons for the higher frequency of occurrence and severity of faults in some specific portions of water distribution networks apparently "similar" to others where damages are less frequent and severe. Key Points: Several laboratory transient tests are carried out in a polymeric looped water distribution network (WDN) due to deterministic and stochastic consumption variationsThe results may help the water utilities to identify the reasons for the high occurrence and severity of faults in some portions of WDNsThe reasons for faults may be repetitive and fast consumption changes, especially at night, and a high small‐diameter pipe percentage [ABSTRACT FROM AUTHOR]

Many waste clay bricks have been produced when brick concrete buildings are demolished; at the same time, grouting treatment in goaf ground needs lots of cement. Waste‐clay‐brick‐powder (WCBP) is proposed to replace a large part of the cement to prepare environmentally friendly slurry suitable for ground grouting in mine goaf. Laboratory tests of replacing 50–90% of cement with WCBP are carried out. Bentonite and water‐reducing agent are used to optimize the slurry based on the performance indexes of water‐separation ratio, stone rate, viscosity, setting time, and compressive strength. Scanning electron microscopy (SEM) tests are also conducted to investigate the microscopic mechanism of some WCBP‐cement samples. Test results show that the slurry made of 20% cement, 70% WCBP, 10% bentonite, and 0.15% water‐reducing agent can meet the needs of ground grouting in mine goaf, and its stone rate is 12% higher than that of pure cement slurry. SEM results show that the WCBP in the early stage mainly exerts the microaggregate effect, and the pozzolanic activity in the later stage plays a role in supplementing the strength. [ABSTRACT FROM AUTHOR]

Determination of rock abrasivity using the LCPC test – Recommendation No. 24 of the Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e. V. The Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e. V. (German Geotechnical Society) is compiling instructions for rock testing in laboratory and in situ and for monitoring of rock masses and civil engineering structures. This recommendation No. 24 deals with the LCPC test for investigating hard rock samples in order to determine the abrasivity and the crushability of hard rock. The requirements for the test facility and sample preparation as well as the procedure for carrying out and evaluating LCPC tests are specified. The LCPC test was developed by the Laboratoire Central des Ponts et Chaussées and is used to classify the abrasivity and crushability of rock. This recommendation takes into account the French standard NF P 18‐579: 2013‐02 [1], but goes beyond it in terms of testing procedure and evaluation. The abrasivity index is determined by exposing a defined steel test plate to a granular sample at a defined speed of rotation for a defined amount of time. The material loss of the test plate is measured and applied for the calculation of an index value for the abrasivity of the original hard rock sample. In addition, an index value for the crushability can be determined from the change in grain size compared to the initial sample. [ABSTRACT FROM AUTHOR]

The equivalent quartz content – historic review and its future application in abrasivity prediction The assessment of the abrasion resistance of minerals and their influence is an important aspect in engineering geology and rock mechanics. Questions with regard to rock excavation and the expected wear parameters play a decisive role. Various test methods have been developed over the decades to assess the hardness properties and abrasiveness of minerals and rocks. These include direct tests on rock samples, hardness tests but also parameters derived from mineralogical and petrographic data, such as the equivalent quartz content FEQ. The values used today for determining the FEQu exist since more than 100 years, and are named after August Rosiwal (1860–1923), the pioneer in the field of grinding tests, referred to as Rosiwal factors. The present work deals with this approach, compiles the factors of various authors, and establishes correlations with other hardness parameters. Using laboratory data, the FEQu are calculated and compared amongst the different sources. It is also shown how the FEQu can be directly related to the widely used cerchar test, on the basis of cerchar abrasivity index (CAI) values of selected reference minerals. The FEQu cannot record structural influences, but quartz as a common reference in the cerchar test and FEQu offers the possibility of directly linking the two parameters. [ABSTRACT FROM AUTHOR]

Contribution to the geomechanical parameters of Nuremberg Keupersandstone for the intersection‐free upgrading of the Franconian rapid road Nuremberg (middle section) For upgrading the Franconian rapid road to an expressway, a tunnel with deeper gradient is planned in the middle section. The tunnel will be driven conventionally in the formation Blasensandstein of the Triassic Keuper, and mostly in the soft to medium‐hard class of this Nuremberg Keuper sandstone. Furthermore, the tunnel will cross under some of railway embankments. For warrantying the operation safety during the tunnel construction with a cover depth up to 18 m, a high demand with regard to limiting the deformation and settlement of the railway embankment has been required by the German Railway. In order to make a realistic prediction of the deformation and settlement behavior due to the tunnel construction, a lot of triaxial tests on sandstone samples in the range of from soft, medium‐hard to hard have been executed. In this process, the influence of lateral stress as well as unload‐ and reload‐loop on the stiffness of sandstone has been particularly studied. For the evaluation of the test results, the constitutive relationship of the Hardening‐Soil‐Model has been applied. Arising from these results, the applicability of the Hardening‐Soil‐Model to the Nürnberger Keuper sandstone has been checked and assessed, in dependence of sandstone class and compression strength. Then, the relevant geomechanical parameters have been determined and recommended for design. In this contribution, the essential research results are illustrated and reported. [ABSTRACT FROM AUTHOR]

Compression behavior of sand‐silt mixtures The choice of an appropriate material model for mixed‐grained soils is crucial for the design of a challenging geotechnical structe. For the development of an accurate material model, the experimental investigation of the soil is indispensable. Hereby, the compression behavior of sand‐clay mixtures is investigated on the basis of oedometer tests of mixtures with different fines contents. It can be observed that with increasing fines content, the compressibility of the material increases significantly. Nevertheless, an exponential relationship between equivalent void ratio e* and vertical strain has been established independently of the fines content. On this course, the deformation model of Ohde (1939) was generalized to mixtures by considering e*. The simulations with hypoplasticity for granular soils and with the AVISA‐model for fine‐grained soils show a need for the coupling of the preconsolidation pressure as well as the normal consolidation line at a 1:1 ratio of sand to silt depending on the fines content. [ABSTRACT FROM AUTHOR]

Appropriate local stress fields in crane runway girders due to wheel load This paper summarises the basis of design and further development of local stresses in crane runway girders. Moreover, three test series on crane runway girders in the laboratory are presented which lately have been conducted at Graz University of Technology. The following girders have been investigated: a hot‐rolled section with welded flat rail for light crane service, a welded box section for medium crane service and a welded I‐section with A 120 rail for heavy crane service. For all cases, the essential results are summarised and compared to additional finite element calculations and corresponding code regulations. Thus, the reader is able to assess the accuracy of the formulae for local stresses in crane runway girders. The presented latest findings will also be included in the second generation of EN 1993‐6, which is under development at the moment. [ABSTRACT FROM AUTHOR]

Aim: Dutch national guidelines on follow‐up of paediatric celiac disease (CD) are available. The primary aim was to evaluate guideline adherence by paediatricians during follow‐up. The secondary aim was to determine the clinical relevance and diagnostic yield of routine laboratory tests suggested by these guidelines. Methods: A retrospective, single‐centre, cohort study was performed in paediatric CD patients who visited Tergooi Hospital, the Netherlands, between January 2017 and December 2019, with follow‐up of at least twelve months after diagnosis. We analysed guideline adherence, number of outpatient visits and all laboratory data. Results: We included 91 CD children with a median follow‐up of 4.0 years (range 1–16 years) and 162 follow‐up visits. Strict adherence amongst paediatricians during follow‐up was 8.0% (13/162 cases). A total of 1570 laboratory tests were performed of which 45.4% (713/1570) was in strict compliance with the Dutch national guidelines. Clinically relevant deviations were observed in 5.3% of requested laboratory tests. Conclusion: Strict guideless adherence amongst paediatricians in follow‐up of paediatric CD was low and the clinical relevance of the suggested routine laboratory tests is limited. This underlines the increasing notion that evidence‐based guidelines on follow‐up of CD are warranted. [ABSTRACT FROM AUTHOR]

Polymer flooding technology is widely used to enhance the oil recovery, but it increases the viscosity of the produced liquid, making the subsequent water treatment more challenging. Application of polymers impacts separation performance of hydrocyclone, which is an important equipment of produced liquid preseparation and sewage treatment in oil fields. In this work, the effect of polymer solution concentrations on the separation performance of hydrocyclone was studied by using sensitivity analysis. The sensitivity was calculated by numerical simulation, and the influence of polymer concentration on velocity field, pressure field, oil volume fraction, and separation efficiency of hydrocyclone was evaluated. The prototype was processed according to the similarity principle of fluid mechanics, and the relevant laboratory tests were carried out to verify the accuracy of simulation results. Within the tested range (100‐1000 mg/L), the increase of polymer solution concentrations caused adverse impacts on the velocity field, pressure field, and oil volume fraction of the hydrocyclone. When the concentrations of polymer solution reached 800 mg/L, the separation efficiency was reduced to less than 60%. The sensitivity sequence obtained by calculation is as follows: underflow outlet pressure drop > overflow outlet pressure drop > axial velocity > radial velocity > tangential velocity > pressure drop ratio. The change of pressure drop at underflow and overflow outlets was the primary cause for poor separation performance of hydrocyclone. The work can be used to guide the design and application of hydrocyclone for efficient treatment of polymer‐containing treatment liquid. [ABSTRACT FROM AUTHOR]

The alterations in the hemostatic balance in COVID‐19 patients are strongly disturbed and contribute to a high prothrombotic status. The high rate of venous thromboembolism in COVID‐19 patients goes along with derangements in coagulation laboratory parameters. Hemostasis testing has an important role in diagnosed COVID‐19 patients. Elevated D‐dimer levels were found to be a crucial laboratory marker in the risk assessment of thrombosis in COVID‐19 patients. The diagnostic approach also includes prothrombin time and platelet count. Fibrinogen might give an indication for worsening coagulopathy. Other markers (activated partial thromboplastin time (aPTT), fibrinolysis parameters, coagulation factors, natural anticoagulants, antiphospholipid antibodies and parameters obtained by thromboelastography or thrombin generation assays) have been described as being deranged. These may help to understand the pathophysiology of thrombosis in COVID‐19 patients but have currently no place in diagnosis or management in COVID‐19 patients. For monitoring the heparin anticoagulant therapy, the anti‐Xa assay is suggested, because the severe acute‐phase reaction (high fibrinogen and high factor VIII) shortens the aPTT. [ABSTRACT FROM AUTHOR]

Behaviour of lattice towers with angle profiles Four experimental large‐scale tests on angle section lattice towers are presented that have been carried out in the frame of ANGELHY, an RFCS (Research Fund for Coal and Steel) research project. The towers were subjected to pushover loading, applied in orthogonal or diagonal direction at their top. Failure occurred due to buckling of the braces or the legs, depending on the lay‐out. This paper presents first the experimental tests. Then, the experimental tests are recalculated through the currently available design model. It is shown that this design model correctly predicts the failure modes. However, it is also shown that the Eurocode 3 provisions are very conservative and need to be improved. Therefore, a second design model has been applied to recalculate the towers. This alternative design model is more refined concerning the modelling of the tower and concerning the resistance checks. The application of the alternative design model leads to more precise results compared to the laboratory tests and to an increase in the tower resistances that are approximatively 10–30 % higher than those obtained by the current Eurocode 3 model. [ABSTRACT FROM AUTHOR]

Determination of rock abrasivity using mineralogical‐petrographical methods – Recommendation No. 25 of the Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e. V. The Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e. V. (German Geotechnical Society) is compiling suggestions for rock testing in laboratory and in‐situ and for performing monitoring of rock masses and civil engineering structures. Recommendation No. 25 deals with the determination of mineralogical‐petrographic parameters from hardrock samples in order to assess hardrock abrasivity. It specifies the requirements for testing equipment and test specimen, the procedures to perform and to evaluate thin‐section and powder X‐ray diffractometer analysis and the methods for deriving various index values for abrasivity assessment. Petrographical analysis provides information about the type and amount of a rock's mineral composition as well as on its structural properties. This information can be applied for the characterization of rock abrasivity either by use of direct values (for instance quartz content) or in the form of index values (for instance Equivalent Quartz Content, Schimazek Index or Rock Abrasivity Index). [ABSTRACT FROM AUTHOR]

Impacts on rigid barriers by flow‐like gravitational mass movements The climate‐change‐induced influences on the environment represent an increasing importance and challenge for the evaluation of flow‐like rock avalanches. Extreme conditions for settlement areas in the alpine region result in the necessity to erect protective structures. Rock avalanches increasingly threaten people and infrastructure in settlement and economic areas in Alpine regions. The design impact based on empirical models, areas of influence, deposition sites and flow depth can be roughly estimated. Very different (mostly unknown) input parameters are required for the different numerical programs based on continuum mechanics. For a more precise definition of the relevant parameters, model tests are often carried out to validate the different design models. The basis of the present model experiment is the experimental setup and the investigations at the University of British Columbia which were replicated and extended at the University of Innsbruck. [ABSTRACT FROM AUTHOR]

The behaviour of granular materials, such as sands, is controlled by the interaction of particles. This interaction can be described geometrically by orientations and statically by forces. Using x‐ray μ‐tomography and image analysis, it is possible to determine the geometrical fabric at the grain‐scale, whereas the forces still remain inaccessible in natural granular materials. This article shows how the fabric can be accessed using standard and recently proposed advanced image analysis techniques and elaborates which problems arise when describing the fabric quantitatively. These techniques were applied to a triaxial compression test on Hostun sand. The results are described in terms of a fabric tensor, a coordination number and an anisotropy and then related to the macroscopic behaviour of the sample. [ABSTRACT FROM AUTHOR]

Weathering dependent disintegration and softening processes of weak claystones Weak rocks can lose their strength within a short period of time when dried out and rewetted. In a laboratory study a new method for the classification of the disintegration behaviour of weak rocks was developed, which allows an unambiguous determination of the disintegration potential. In addition, it was investigated in more detail which rock properties influence the disintegration tendency of the rocks. It was found that the natural weathering condition strongly influences the disintegration tendency. The reason for this is a sulphate content decreasing with weathering and an increasing content of interaggregate pores. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID‐19) pandemic continues to cause significant morbidity and mortality worldwide. This study aims to identify specific lab markers, complications, and treatments that may be associated with increased mortality in COVID‐19 patients. This study is retrospective in nature; it included 217 COVID‐19 positive patients who were admitted to a ProMedica Health System hospital in Northwest Ohio, United States, between March 25 and June 16, 2020. We collected various laboratory values, complications, and treatment courses. T test and χ2 analyses were used to predict mortality. COVID‐19 test was confirmed via polymerase chain reaction. Of 217 patients included in the study, the mean age of the population was 63.13 (SD, 17.8), of which 194 (89.4%, mean age 61.7 years) survived while 23 (10.6%, mean age 74.6 years) died. Among them, 53% were females and 47% male. Laboratory values that were associated with mortality were low hemoglobin (p =.0046), elevated INR (p =.0005), low platelets (p =.0246) and elevated procalcitonin (p =.0472). Marginally significant laboratory values included elevated troponin (p =.0661), and elevated creatinine (p =.0741). Treatment with either antibiotic, antifungals, antivirals, blood transfusion, steroids, and intubation were all statistically significant for mortality. COVID‐19 related complications with either ARDS, myocarditis, elevated INR, septic shock, or age greater than 63 were significant predictors of mortality. Low hemoglobin, elevated INR, Low platelet, elevated procalcitonin, treated with either antibiotic, antifungal, antiviral, blood transfusion, steroids, and intubation are associated with high mortality related to COVID‐19 infection. Healthcare professionals must be aware of these predictors. Highlights: ‐The COVID‐19 pandemic continues to cause significant morbidity and mortality worldwide.‐Age greater than 63 has been linked to higher mortality in COVID‐19 positive patients.‐Certain lab values have been shown to be associated with higher mortality, those being low hemoglobin, elevated INR, low platelet, and elevated procalcitonin.‐Treatments with antibiotics, antifungals, antivirals, blood transfusion, steroids are also associated with higher mortality. [ABSTRACT FROM AUTHOR]

Classifying the subsoil into homogeneous areas for tunnel drives using tunnel boring machines in soft soil – parameters, tunnel sections, examples Since 2015, classifying the subsoil into homogeneous areas plays an important role for the calculation and construction of infrastructure projects. Currently, the number of projects with tunnel boring machines in soil, that consider homogeneous areas, is small, but will increase in the next couple of years. At the tunnel face in soft soils many layers could be present, that have to be considered for classifying the subsoil. The paper enlarge on essential characteristics for the division of the subsoil into homogeneous areas for TBM drives and takes into account DIN 18312:2019 and the updated recommendation for the choice of tunnel boring machines by the DAUB. In this paper, recommendations will be summarized, which tests beside the tests mentioned in DIN 18312:2019 should be done to describe the soil for the tunnel drive. Options to classify the subsoil in different soil conditions and possibilities to consider the homogeneous areas in the specifications will be shown. Based on these options, recommendations will be presented, how the consideration of geotechnical and tunneling parameter will lead to a transparent tender for projects with tunnel boring machines in soft soil. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical characteristics and laboratory test results in pregnant women with coronavirus disease 2019 (COVID-19).Methods: A retrospective study to review and compare clinical data including electronic medical records and laboratory tests from pregnant and nonpregnant patients admitted the Central Hospital of Wuhan, China from December 8, 2019 to April 1, 2020.Results: A total of 72 women (30 pregnant and 42 nonpregnant) with COVID-19 were included. No patients developed severe pneumonia during the study. Compared with the nonpregnant group, pregnant patients were admitted to hospital earlier (0.25 vs 11.00 days; P<0.001), presented milder symptoms, had a higher rate of asymptomatic infection (26.7% vs 0%), and shorter length of hospital stay (14.5 vs 17.0 days; P<0.01). Laboratory test results showed that levels of inflammation markers such as white blood cell count, neutrophil count and percentage, C-reactive protein, procalcitonin, and D-dimer were significantly higher in pregnant women, whereas mean lymphocyte percentage was significantly lower compared with nonpregnant women.Conclusion: In some respects, the clinical characteristics and laboratory test results of COVID-19 in pregnant patients seems to be distinctive from their nonpregnant counterparts. Appropriate advice and positive treatment might be critical to the prognosis when dealing with these pregnant patients. Pregnant patients with COVID-19 had their own positive clinical characteristics and special laboratory test results. Responsive medical advice and active treatment for those patients are critical to recovery. [ABSTRACT FROM AUTHOR]

Insects ensure the survival of their offspring by depositing their eggs in suitable environments. Even generalist egg‐laying insects often show preferences for specific host plants. The cocoa pod borer (CPB), Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae), successfully infests and reproduces on relatively few host plants, but has a major economic impact only on cocoa, Theobroma cacao L. (Malvaceae). Choice tests were performed in the laboratory to compare the frequency of insect visits, the duration of the visits, and the number of eggs laid on the fruits for each combination of host plants tested – that is, cocoa clones or fruits of rambutan (Nephelium lappaceum L.), Fijian longan (Pometia pinnata JR Forst & G Forst, both Sapindaceae), and langsat (Lansium domesticum Corrêa, Malvaceae). Our laboratory study showed that, when given the choice, CPB significantly favored cocoa pods over other host fruits (rambutan, langsat, or Fijian longan). Females also deposited more eggs on unripe fruits than on ripe fruits of similar size. The preference to lay eggs on specific cocoa clones in the bioassays did not reflect the level of the clone resistance to CPB damage reported from the field. Consequently, oviposition preference of female CPB does not seem to be the main factor explaining field resistance of some cocoa clones to CPB infestation. [ABSTRACT FROM AUTHOR]

Prediction of the strength evolution of cement‐treated soils by means of the Porosity/Binder‐Index The usability of marginal soils for earthwork construction purposes can be improved by employing soil treatment measures. The applicability of such measures has to be confirmed in advance by laboratory tests. Within the scope of German road construction regulations concerning such suitability tests, the quantity of binder is varied exclusively. Unfortunately, the evaluation of the data obtained from such tests does not permit any generalizations beyond the mixtures actually investigated, and the influence of dry density on strength of treated soils cannot be accounted for. The present study reports on the applicability of a method to realistically capture the relationship between compressive strength, dry density (porosity) and binder content to non‐homogeneous mixtures. The analysis is based on test results from unconfined compression tests on specimens produced from mixtures of three fine‐grained soils respectively with cement. It is shown that the method can principally be used for such mixtures and it is also shown which boundary conditions apply for a proper use. Recommendations for the application of the method within the scope of suitability testing are presented. [ABSTRACT FROM AUTHOR]

Shear behavior of acrylate gel grouted bodies – Safety‐relevant findings on the selection of the failure criterion Pore space grouting with acrylate gel is carried out to increase the strength and seal the subsoil. In order to assess the stability of a structure after the grouting process, the grouted bodies must be examined for their soil mechanical behavior. The shear strength is often described with the Mohr‐Coulomb failure criterion for soil and rock. Experimental laboratory tests on an acrylate gel grouted body have shown that the increase in shear strength is not linear with increasing normal stress and, in consequence of the Mohr‐Coulomb failure criterion, the strength of the grouted body is overestimated. Based on this knowledge, numerical comparison calculations were carried out on an excavation pit. In the calculations, the failure criteria according to Mohr‐Coulomb and Hoek‐Brown were taken into account. Based on the experimental and numerical investigations, a failure criterion relevant for the construction practice for acrylate gel grouted bodies is determined in order to correctly assess the strength and stability of a building. [ABSTRACT FROM AUTHOR]

Geotechnical investigations on modified steel slags. Extensive experimental investigations have shown that the water permeability of steel slags can be reduced by the addition of fine‐grained additives, such that they can be used as additional sealing layer, in accordance with the technical recommendations for the use of soils and building materials with environmentally relevant substances in earthworks (M TS E). The experimental investigations were carried out on three steel slags which were granulometrically modified using four fine‐grained additives. The results of the water permeability tests show that the coefficient of permeability kf ≤ 1 ⋅ 10–8 m/s can already be achieved with an addition of 8 wt.‐% fine‐grained additives. In comparison to natural soils, it should be noted that steel slags generally require a higher compaction energy (modified proctor energy) to achieve a low air void ratio with accompanying additional reduction of their water permeability and that the swelling capacity of sodium‐activated bentonite can be reduced due to the high ion concentration in the pore solution. [ABSTRACT FROM AUTHOR]

This article presents a specific procedure to control the standard test conditions (STC) power in photovoltaic (PV) modules. It also shows the results of its application on a supply of approximately 700 000 multicrystalline p‐type silicon BSF technology PV modules made by a worldwide known manufacturer (Tier‐1, Q4 2015). First, during the manufacturing process, the analysis of the STC power measurements of the whole supply carried out by the modules' manufacturer is included, where the quality of these measurements was evaluated through a comparative contrast study in an independent laboratory on a sample of 4000 modules. In addition, the light‐induced degradation (LID) on 180 modules and the resistance to the potential induced degradation (PID) in a sample of 125 modules were characterized and critically analyzed. Secondly, during operation phase, the analysis of the STC power after the first 2 years of operation of the modules in desert conditions was also included. These measurements were carried out on a sample of 2000 modules making use of an accredited mobile laboratory. The overall results showed the effectiveness of the implementation of the aforementioned procedure, which is based on the use of a set of reference modules (primary standards) with common calibration origin. It proved to be an effective way of reducing uncertainties all along the quality control process. The susceptibility to PID, as observed on the PID test (chamber method) specified in IEC TS 62804, was practically negligible, and the average LID degradation after 20 kWh/m2 of exposition to the sun was 1.5%. Finally, the degradation rate in the second year of operation was 0.32% with respect to the initial degradation occurred during the whole first year. [ABSTRACT FROM AUTHOR]

Results of a round robin test referring to DGGT testing recommendation no. 23: Cerchar test. At least since its reference in the General Technical Terms of Contract (VOB/C), the Cerchar scratch test can be regarded as standard procedure for the determination of hardrock abrasivity in Germany. The test is usually carried out with reference to testing recommendation no. 23 of the national Commission on Rock Testing (working group 3.3) of the Deutsche Gesellschaft für Geotechnik e. V. (German Geotechnical Society), which was published in 2016. In order to verify the aim of this recommendation, i.e. the standardization of the test procedure, a round robin test was organized as part of a master thesis at TU Darmstadt. In total, a number of 17 rock mechanical laboratories from Germany and Austria participated in the test and test results were evaluated according to DIN ISO 5725 in order to analyze their precision. An evaluation of the test and its results shows, that the Cerchar method, based on recommendation no. 23 can be considered as a generally suitable testing method for the assessment of hardrock abrasivity. However, the results emphasize, that an appropriate interpretation of CAI test results should always take into account the specific variation of measured values, which significantly depends on the composition and microstructure of the tested rock material. Regarding the quantification of variability, the Cerchar round robin test is able to provide valuable baselines. In addition, some recommendations for further optimization of the testing procedure were derived. [ABSTRACT FROM AUTHOR]

Anchor sticks for thin walls made out of carbon reinforced concrete Carbon reinforced concrete is no stranger anymore. Non‐corrosive properties made it popular for the use in slender and filigree structures. For example, to reduce their thickness, carbon reinforced concrete is well suitable for the wall shells of an element wall. However, thus the bonding depth is reduced and conventional built‐in parts cannot be used anymore. Therefore, a new anchor stick for the connection of the two wall shells was developed, and its mechanical and thermal properties were examined. The results of these first investigations are presented in the paper. [ABSTRACT FROM AUTHOR]

Quantitative determination of clogging potential of fine grained soils based on adhesion tensions – Current investigations and new results. Clogging on parts of the tunnel boring machine can generally occur according to the properties of the soil in case of tunnel drives with shield machines mainly in fine grain soils. Clogging could have a great influence on the advance speed and thus on the economy of a project. In previous investigations i.a. properties of the soils and the clogging potential was estimated qualitatively. The results of the own investigations are presented and a quantitative estimation of the clogging potential of different soils is possible. Further systematic investigations were done with additives. The quantitative categorization shall help to estimate the clogging potential more precisely to make the tunnel drive in clay and silt more efficient. [ABSTRACT FROM AUTHOR]

Assessment of abrasion resistance of improved soils in single wheel tester. Driving on unpaved roads during dry periods may lead to unwanted dust formation with negative consequences for traffic safety. In case of stronger rain events, insufficient surface sealing can cause erosion and uneven road surface. A cost‐effective and proven stabilization countermeasure is the addition of hydrated lime. A naturally occurring cohesive soil was improved by lime addition and examined with respect to bearing strength and swelling potential. A new, self‐developed wheel test rig for terramechanical applications was used to quantify the increase in abrasion resistance when soil is loaded by a rotating model wheel. The study confirms the significant improvement effect of binder addition. An equation for the rough estimation of the wheel indentation as a function of the number of wheel revolutions is derived from the results. [ABSTRACT FROM AUTHOR]

On the application of single‐board computers in soil mechanical research and teaching using the example of an uniaxial compression test for the investigation of unsaturated granular soils. For some years, single‐board computers and microcontrollers are increasingly applied in circles of hobbyists, in teaching at schools and universities, but also in industry and science. In this contribution, it is demonstrated, how a soil mechanical testing apparatus is developed and built, based on a practical experimental measurement project from soil mechanics research on unsaturated granular soils. The contribution focuses on the application of single‐board computers in soil mechanics research and teaching. Here, different benefits can be found, e. g., from the point of view of research, the liberty of developing new experimental apparatuses, and from the point of view of teaching, the motivation to acquaint students of soil mechanics with laboratory measurement technique and (physical) programming, a domain of civil engineering studies that rather misses out, or that is rather approached very cautiously by students despite its growing importance. [ABSTRACT FROM AUTHOR]

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Validation of a high‐cycle accumulation model based on element tests, model tests and measurements at real buildings The paper summarizes longtime experimental and numerical studies at the Institute of Soil Mechanics and Rock Mechanics (IBF) of Karlsruhe Institute of Technology (KIT) with the aim to validate the high‐cycle accumulation (HCA) model of Niemunis et al. (2005) for sand. First, the accurate reproduction of the results from drained cyclic triaxial tests by the HCA model is demonstrated. Subsequently, finite element simulations of model tests on monopile foundations for offshore wind turbines in different scales are described. For a validation in the 1:1 scale the field test on a prototype of a shallow foundation for offshore wind turbines performed by the Ed. Züblin AG is recalculated. This foundation has been subjected to a cyclic loading simulating several storm events. As another well documented boundary value problem in the 1:1 scale the ship lock Uelzen I has been studied in finite element simulations. In case of a ship lock the cyclic loading of the subsoil results from the changing water levels in the lock chamber. For all studied boundary value problems the determination of the input parameters of the simulations, i. e. the material constants and state variables of the soil, which are based on laboratory or field investigations, is explained. The results of the finite element simulations of the different problems are compared to the laboratory or field measurements. [ABSTRACT FROM AUTHOR]

Background: The overuse of medical tests leads to higher costs, wasting of resources, and the potential for overdiagnosis of disease. This study was designed to determine whether the patients of family doctors who order more routine medical tests are diagnosed with more cancers. Method: A retrospective population‐based cross‐sectional study using administrative health care data in Ontario Canada. We investigated the ordering of 23 routine laboratories and imaging tests 2008‐20012 by 6849 Ontario family physicians on their 4.9 million rostered adult patients. We compared physicians' test utilization and calculated case‐mix adjusted observed to expected (O:E) utilization ratios to categorize physicians as Typical, Higher or Lower testers. Age‐sex standardized rates (cases/10 000 patient years) and Rate Ratios were determined for cancers of the thyroid, prostate, breast, lymphoma, kidney, melanoma, uterus, ovary, lung, esophagus, and pancreas for each tester group. Results: There was wide variation in the use of the 23 tests by Ontario physicians. 26% and 24% of physicians were deemed Higher Testers for laboratory and imaging tests, while 41% and 38% were Typical Testers. The patients of higher test users were diagnosed with more cancers of thyroid (laboratory [RR 1.61, 95% CI 1.39‐1.87] and imaging [RR 2.08, 95% CI 0.88‐2.30]) and prostate (laboratory [RR 1.10, 95% CI 1.03‐1.18] and imaging [RR 1.05, 95% CI 1.00‐1.10]). Conclusion: There is a wide variation in the ordering of routine and common medical tests among Ontario family doctors. The patients of higher testers were diagnosed with more thyroid and prostate cancers. The overuse of medical tests leads to higher costs, wasting of resources and the potential for OverDiagnosis of disease. Using electronic health care data we determined the rates of 23 routine medical tests and the rates of 12 new cancer diagnoses for the 4 900 000 patients of 6849 family doctors in Ontario Canada. We found that the patients of the doctors who ordered more tests than their peers had increased rates of thyroid and prostate cancers consistent with the literature on OverDiagnosis. [ABSTRACT FROM AUTHOR]

Summary: Proper understanding of the deviatoric behaviour of peats represents a challenge in soil mechanics. Exceptional high compressibility together with extremely high friction angles distinguishes peats from classical organic soils. Considerable amount of triaxial test data on peats can be found in the literature, mostly coming from standard undrained triaxial compression tests. However, only a minor part was intended to describe their prefailure behaviour. Also, limiting the investigation to the undrained response reduces the information on those ingredients of constitutive models, which are necessary to describe the deformational behaviour. This contribution aims to provide better insight into the prefailure deformational behaviour of peats, by analysing in detail the results of non‐standard drained tests at various stress paths and undrained tests performed on reconstituted peat samples. Based on the experimental findings, an existing hypoplastic model, originally developed for fine‐grained soils, has been adapted to capture the behaviour of peats. The model is directly calibrated on selected experimental results and validated on a variety of different stress path tests. The results reveal the merits of hypoplasticity in modelling the nonlinearity of the prefailure behaviour and the directional response of peats, which both are of great importance when assessing the serviceability limit states of geotechnical structures founded on peats. [ABSTRACT FROM AUTHOR]

Classification of the weathering‐dependent disintegration behaviour of weak rocks. Weak rocks lose their cohesion within a short period of time when dehydration and rewetting occur. Understanding the disintegration behaviour of weak rocks is crucial for geotechnical engineering and construction. In the framework of this research, the weathering‐dependent tendency of Keuper Marls to disintegrate is examined in particular. The disintegration behaviour of a rock is usually investigated by means of drying‐wetting‐cycles. Various indices and approaches for classifying the disintegration tendency have been proposed in the literature. However, the approaches are only of limited use for the investigation of weathering‐dependent tendency to disintegrate. For more precise determination of the disintegration behaviour drying‐wetting‐cycles were carried out on differently weathered Keuper Marls. On the basis of these investigations, a new evaluation scheme for the assessment of weakness is derived and its applicability for the classification of the weather‐dependent disintegration tendency is verified. [ABSTRACT FROM AUTHOR]

About the extraordinary swelling behaviour of Tarras Clay. In the course of the currently ongoing variant analysis for a new fixed link across the Fehmarnsund Tarras Clay has been found at various depths. Just like 50 years ago, it presents a serious challenge to the construction measures. Especially the shrinkage and swelling behaviour of the clay as well as its very low shear strength in the area of slickensided discontinuities may cause serious problems with regard to a new bridge or tunnel construction. This article compares the composition, the microstructure and the swelling behaviour of different soil samples that were classified as pure Tarras Clay in order to point out correlations. For instance, it was shown that no reliable statement can be made about the swelling behaviour based on the grading curve of the examined clay samples. However, plasticity index and water absorbency represent much more reliable indicators. Two clay samples were tested, whose granulometric composition, clay mineralogy and settlement behaviour were almost the same, but their swelling properties were found to be very different. In this article the reasons are discussed and the microstructure of Tarras Clay is analysed in greater detail. Furthermore, the test results are compared to literature values of better researched London Clay. [ABSTRACT FROM AUTHOR]

Abstract: The Chair of Subsurface Engineering at the Montanuniversitaet Leoben is part of the Department of Mineral Resources Engineering. Regarding research and development, the chair cooperates with several departments of the university, such as the Departments of Petroleum Engineering, Environmental and Energy Technology, Product Engineering and Polymer Engineering. In addition to the construction of the ZAB, a research and development but also training and education centre at the Styrian Erzberg, some other research projects at the chair have recently been reported in this journal. These include, for example, research on segmental lining design in collaboration with with the ÖBB‐Infrastruktur AG, and also topics such as disc force and face monitoring systems for TBMs. This research is deliberately not discussed here; rather research is reported that has received less attention lately. This includes further developments mainly relating to laboratory tests, the research field of rockfall simulations, international research cooperations, and also work on BIM implementation at the ZAB‐Zentrum am Berg. [ABSTRACT FROM AUTHOR]

Abstract: Behaviour of sand under cyclic loading with direction change in simple shear test. In the present paper the results of the experimental and numerical investigations of the deformation behavior of sand under cyclic loading with polarization changes are presented. In the case of a polarization change, the accumulated strain rate rises abruptly. With the focus on this phenomenon, an extensive test program has been carried out in the simple shear device with changeable shear direction. Based on these results a new approach for describing the polarization change in the explicit accumulation model is formulated. [ABSTRACT FROM AUTHOR]

Bending tests on two clays and deformability verification for a multifunctional landfill liner. Bending tests provide a practical alternative for the indirect determination of the limit tensile strains in clayey soils as required in the deformability check of compacted clay liner (CCL) in landfills. Two clays were examined in this regard. Three- and four-point tests as well as tests with uniform loading have been performed. The back-calculation of the strains from the deflection is accomplished on the basis of a FEM model by considering the beam as continuum, and a comparison with conventional methods based on beam theory is carried out. The results are then applied to verify the deformability of a multifunctional sealing layer within a landfill-over-landfill system. The strains in the landfill are also determined via the FEM. The soil mechanical input parameters are derived from the evaluation of in-situ measurements. The paper describes the experimental techniques, the test results, the data interpretation procedure, and the individual steps of the verification. [ABSTRACT FROM AUTHOR]

Soil stabilization with binders in geotechnical engineering - laboratory testing procedures and derivation of design parameters. Soil stabilizations with binders are carried out to improve strength and load bearing capacity of soft soils in order to reuse these soils and to meet the project requirements. The main target of geotechnical soil stabilization is the increase in the strength properties of the native soil. Therefore, mostly cements and binders rich in cement are used for these applications. In this article the laboratory tests are explained, which can be used in order to determine the optimum type of binder and the minimum binder dosage that is needed to fulfill the project requirements. In addition to the standard test methods, a rapid test method is introduced, which enables a qualitative evaluation of the hardening potential of a given soil-binder-mixture. Based on the test results under support of a newly developed database forecast tool it is also possible to predict the strength development of the soil-binder-mixture quantitatively. Finally an exemplary proposal for the derivation of design parameters of soil-binder-mixtures is introduced. For this approach a database of nearly 190 compressive strength test results of various soil-binder-mixtures has been used. [ABSTRACT FROM AUTHOR]