Determining the dissipative properties of a flexible pipeline’s material at stretching in the transverse direction taking its structural elements into consideration

This paper reports an experimental study that determines the dissipative properties of a pressure fire hose, the type of «T», whose inner diameter is 77 mm, under the static load conditions, taking into consideration the structural elements of the hose in the transverse direction. For this study, experimental samples were separated from the different sections of the hose. The study involved both the outer fabric reinforced frame and the internal waterproofing rubber layer of the pressure fire hose. A series of field experiments were carried out while stretching the samples under the conditions of static loading-unloading cycles. The tests included 7 cycles, which were carried out in a two-minute interval for the material of the hose. The study results showed that during the first two to three cycles, the materials manifest a short-term creep that stabilizes under modes 4‒7. The results from experimental research were approximated by polynomial trend lines. The deformation of samples demonstrated the curves that, under the conditions of cyclic loading and unloading, formed hysteresis loops. When analyzing the appropriate curves, it was found that, first, during the first two-three loading-unloading cycles the area of the hysteresis loops decreases, second, the inclination angle of hysteresis loops also decreased during each subsequent loading-unloading cycle. It was established that the dissipation coefficients of the hose material stretched in the transverse direction are significantly reduced under the first three test modes in the range from 0.49 to 0.37. At subsequent tests (cycles 4–7), dissipation coefficients stabilize at the level of 0.18 for the reinforced frame, and 0.316 for the rubber layer

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684. Cardiac Safety in Adults with Community-Acquired Bacterial Pneumonia (CABP) Treated with Lefamulin (LEF) or Moxifloxacin (MOX): Analysis of Lefamulin Evaluation Against Pneumonia (LEAP) 1 and LEAP 2 Study Results

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.752 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S311-S311

Author(s):

Borje Darpo ◽

Anita F Das ◽

Daniel Stein ◽

Jennifer Schranz ◽

Steven P Gelone

Keyword(s):

Torsade De Pointes ◽

Significant Risk ◽

Study Drug ◽

Qt Prolongation ◽

Drug Discontinuation ◽

Cardiac Safety ◽

Study Results ◽

Minute Interval ◽

Clinically Significant ◽

Study Drug Discontinuation

Abstract Background Preclinical data suggest potential effects of LEF on cardiac interval parameters. We therefore assessed LEF cardiac safety from the LEAP 1/2 trials. Methods In LEAP 1, PORT III–V patients received LEF 150mg IV q12h for 5–7 days or MOX 400mg IV q24h for 7 days, with optional IV-to-oral switch (600mg LEF q12h or 400 mg MOX q24h). In LEAP 2, PORT II–IV patients received oral LEF 600mg q12h for 5 days or oral MOX 400mg q24h for 7 days. Patients with known QT prolongation or on medication with potential to prolong the QT interval were excluded as per MOX label. After 5 minutes of rest in the supine position, triplicate 12-lead ECGs were obtained within a 5-minute interval at Screening in both studies, on Days 1/3 in LEAP 1 (predose and ≤15 minutes after first IV dose), and on Days 1/4 in LEAP 2 (predose and 1–3 hours after first oral dose), and sent to a central ECG reader for adjudication. Results Of 1,282 randomized/treated patients (n = 641/group), 1,274 had baseline (BL) and post-BL ECG data (n = 636 LEF, n = 638 MOX). Consistent with the resolution of infection, ECGs revealed mean reductions of 7–8 beats/minute for both groups in both studies. The largest mean change in QTcF from BL to post-BL was on Day 3 in LEAP 1 (13.6 and 16.4 msec with IV LEF and MOX, respectively) and on Day 4 in LEAP 2 (9.3 and 11.6 msec with oral LEF and MOX, respectively). The proportion of patients meeting potentially important post-BL QTcF values/changes was comparable between treatment groups (table). In the standardized MedDRA query of Torsade de pointes/QT prolongation (broad), the most common treatment-emergent adverse event was ECG QT prolonged (n = 4 LEF, n = 5 MOX). All events were nonserious and mild or moderate in severity. 6 events were considered study drug related (n = 4 LEF, n = 2 MOX). 5 events led to study drug discontinuation (n = 2 LEF, n = 3 MOX). In 2 patients with cardiovascular disease, 1 had ventricular arrhythmia on Day 20 (18 days after last LEF dose) and 1 had cardiac arrest on Day 18 (9 days after last MOX dose); both events were fatal and considered unrelated to study drug by investigator. Conclusion Mild prolongation of the QTcF interval was seen with LEF and MOX, with somewhat smaller effects seen with LEF. Given the small effect, LEF is unlikely to pose a clinically significant risk of ventricular proarrhythmia with appropriate precautions and use. Disclosures All authors: No reported disclosures.

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Plastic deformation and fracture of masonry under biaxial stresses

Vestnik MGSU ◽

10.22227/1997-0935.2016.2.34-48 ◽

2016 ◽

pp. 34-48

Author(s):

Oleg Vasil’evich Kabantsev

Keyword(s):

Plastic Deformation ◽

Stress State ◽

Dissimilar Materials ◽

Structural Elements ◽

Plastic Properties ◽

Linear Behavior ◽

Deformation Phase ◽

Study Results ◽

Brick And Mortar ◽

Multicomponent Composite

Masonry is a complex multicomponent composite composed of dissimilar materials (brick / stone and mortar). The process of masonry deformation under load depends on the mechanical characteristics of the basic composite materials, as well as of the parameters belonging to the elements, which define the link between brick and mortar being the structural elements. The paper provides an analysis of the experimental study results of masonry behaviour in two-dimensional stress state at primary stresses of opposite signs; identifies the mechanisms of masonry failure that are in compliance with the conditions of stress state. The work shows the key role that structural elements play in the formation of masonry failure processes. On the basis of failure mechanisms educed from the experiments, there was developed a discrete model of masonry. The processes and the corresponding strength criteria, which play a key role in the implementation of plastic deformation phase, have been detected. It has been shown that the plastic deformation of masonry under biaxial stresses occurs in case of the physical linear behavior of the basic materials (brick and mortar). It has been also substantiated that the plastic properties of masonry under biaxial stresses are determined by the processes occurring at the contact interaction nodes between brick and mortar in bed and cross joints. The values of the plasticity coefficients for masonry depending on the mechanical properties of a brick, a mortar and adhesive strength in their interaction have been obtained basing on the results of the performed numerical investigations.

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Viscoelastic Models Describing Stress Relaxation and Creep in Soft Tissues

MRS Proceedings ◽

10.1557/proc-874-l5.1 ◽

2005 ◽

Vol 874 ◽

Cited By ~ 1

Author(s):

Alexa V. Kobelev ◽

Rimma M. Kobeleva ◽

Yuri L. Protsenko ◽

Irina V. Berman ◽

Oleg A. Kobelev

Keyword(s):

Stress Relaxation ◽

Soft Tissues ◽

Hysteresis Loops ◽

Response Functions ◽

Structural Elements ◽

Deformation Curves ◽

Pulse Column ◽

Time Dependencies ◽

Creep Time ◽

Time Courses

AbstractThe review of our approach to the specific rheological properties modeling of myocardium has been given. We are working on the level of ‘fascicule’ as a tissue element, which consists of several cardiomyocytes surrounded by a connective tissue shell. Actually, these properties are characteristic of large majority of living soft tissues. In order to describe essentially nonlinear static ‘force-deformation’ curves and quasi-static hysteresis loops together with non-exponential stress relaxation and creep time courses we suggest a set of 2D graphs with different topology composed of classical linear Hook's springs and Newtonian damps. Each spring and dashpot represents a group of 3D tissue structural elements. The stress response functions of these models are found for the uniaxial step-wise, or pulse (column-like) external stretching. The inverse response functions of the longitudinal displacement for the external stress loading of the pulse shape time dependencies were also found. The values of elastic modules and viscous coefficients are estimated by comparison theoretical curves of relaxation, creep and recovery with the experimental data. The latter are obtained on rather different objects, passive muscle preparations (the stress relaxation response) and endothelium cells (the creep response). It has been stated that the proposed 2D models appear to be quite general to describe nonlinear relaxation and creep properties, which are lacking in the traditionally used uniaxial 1D models.

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Does Taking a Short Break from Social Media Have a Positive Effect on Well-being? Evidence from Three Preregistered Field Experiments

Journal of Technology in Behavioral Science ◽

10.1007/s41347-020-00189-w ◽

2021 ◽

Author(s):

Andrew K. Przybylski ◽

Thuy-vy T. Nguyen ◽

Wilbert Law ◽

Netta Weinstein

Keyword(s):

Social Media ◽

Negative Affect ◽

Field Experiments ◽

Well Being ◽

Positive And Negative Affect ◽

Social Relatedness ◽

Positive Effects ◽

Study Results ◽

Social Media Platforms ◽

Positive Effect

AbstractConcerns about the consequences of social media use on well-being has led to the practice of taking a brief hiatus from social media platforms, a practice known as “digital detoxing.” These brief “digital detoxes” are becoming increasingly popular in the hope that the newly found time, previously spent on social media, would be used for other, theoretically more rewarding, activities. In this paper, we test this proposition. Participants in three preregistered field experiments (ntot = 600) were randomly assigned to receiving each of two conditions on each of two different days: a normal-use day or an abstinence day. Outcomes (social relatedness, positive and negative affect, day satisfaction) were measured on each of the two evenings of the study. Results did not show that abstaining from social media has positive effects on daily well-being (in terms of social relatedness, positive and negative affect, day satisfaction) as suggested by the extant literature. Participants reported similar well-being on days when they used social media and days when they did not. Evidence indicated that abstinence from social media had no measurable positive effect on well-being, and some models showed significant deficits in social relatedness and satisfaction with one’s day. We discuss implications of the study of social media hiatus and the value of programmatic research grounded in preregistered experimental designs.

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Resistance response of fifteen sweet potato genotypes to scab disease (Sphaceloma batatas) in two growing sites in East Nusa Tenggara, Indonesia

Tropical Drylands ◽

10.13057/tropdrylands/t020102 ◽

2018 ◽

Vol 2 (1) ◽

pp. 5-11 ◽

Cited By ~ 2

Author(s):

YOSEP SERAN MAU

Keyword(s):

Disease Severity ◽

Sweet Potato ◽

Field Experiments ◽

Block Design ◽

Scab Resistance ◽

Resistance Level ◽

Resistance Response ◽

Progress Curve ◽

Randomized Block Design ◽

Study Results

Mau YS. 2018. Resistance response of fifteen sweet potato genotypes to scab disease (Sphaceloma batatas) in two growing sites in East Nusa Tenggara, Indonesia. Trop Drylands 2: 5-11. Field experiments were carried out in two growing locations involving potential sweet potato clones from East Nusa Tenggara Province, Indonesia to: (i) evaluate scab resistance levels of the sweet potato clones, and (ii) identify sweet potato clones with good resistance level to scab disease. The experiment was carried out in the fields employing a Randomized Block Design with a mono-factorial treatment design in each location. The treatment assigned was sweet potato genotype, each consisted of two replicates. The variables observed were disease severity that was assessed at 2, 4, 6, and 8 weeks after inoculation (WAI), which then was used to calculate the Area Under the Disease Progress Curve (AUDPC) of the disease severity. The ANOVA of AUDPC was used to determine the treatment effect, and the disease severity at 8 WAI was used to assess scab resistance level of the sweet potato genotypes tested. The study results showed highly significant differences of disease severities among the tested sweet potato genotypes within each trial location. The majority of the genotypes tested were classified "resistant" or "moderately resistant" to scab disease, except the check clone SLM-01 and KRA-01 that were, respectively, "susceptible" and "moderately susceptible" to scab disease. The majority of sweet potato genotypes evaluated were consistent in their resistance performance in the two trial locations.

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A Low-Cost Automated Test Column to Estimate Soil Hydraulic Characteristics in Unsaturated Porous Media

Geofluids ◽

10.1155/2017/6942736 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

J. Salas-García ◽

J. Garfias ◽

R. Martel ◽

L. Bibiano-Cruz

Keyword(s):

Water Flow ◽

Electrical Resistance ◽

Field Experiments ◽

Full Range ◽

Acquisition Time ◽

Simultaneous Estimation ◽

Study Results ◽

Automated Test ◽

Soil Hydraulic ◽

Infiltration Tests

The estimation of soil hydraulic properties in the vadose zone has some issues, such as accuracy, acquisition time, and cost. In this study, an inexpensive automated test column (ATC) was developed to characterize water flow in a homogeneous unsaturated porous medium by the simultaneous estimation of three hydraulic state variables: water content, matric potential, and water flow rates. The ATC includes five electrical resistance probes, two minitensiometers, and a drop counter, which were tested with infiltration tests using the Hydrus-1D model. The results show that calibrations of electrical resistance probes reasonably match with similar studies, and the maximum error of calibration of the tensiometers was 4.6% with respect to the full range. Data measured by the drop counter installed in the ATC exhibited a high consistency with the electrical resistance probes, which provides an independent verification of the model and indicates an evaluation of the water mass balance. The study results show good performance of the model against the infiltration tests, which suggests a robustness of the methodology developed in this study. An extension to the applicability of this system could be successfully used in low-budget projects in large-scale field experiments, which may be correlated with resistivity changes.

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Field Experiments and Numerical Analysis of the Ground Vibration Isolation of Shock Wave Propagation under Explosion Shock Loading

Vibration ◽

10.3390/vibration2040019 ◽

2019 ◽

Vol 2 (4) ◽

pp. 300-310 ◽

Cited By ~ 2

Author(s):

Wang

Keyword(s):

Finite Element ◽

Numerical Analysis ◽

Vibration Isolation ◽

Field Experiments ◽

Structural Model ◽

Ground Vibration ◽

Blast Waves ◽

Blast Effects ◽

Study Results ◽

The Impact

Because blast effects can jeopardize the safety of facilities, controlling blast hazards is critical in engineering design and construction. The attenuation and amplification effects generated by blast waves are affected by the topography and terrain of the blast area. This study examined the effects of topography on the propagation of seismic waves induced by explosions. From the perspective of explosion control, this study adopted explosion mechanics theories and conducted in situ explosion tests to verify finite element numerical simulation results. This study employed the finite element analysis program, to construct a 3D solid structural model to examine fluid–solid coupling, and the Multi-Material Arbitrary Lagrangian–Eulerian algorithm was adopted to develop a dynamic numerical analysis model. By analyzing the propagation of blast waves and ground vibration effects, this study examined the impact of topographical differences on blast effects. The study results may provide a reference for controlling vibration hazards subject to shock waves from explosions, in order to reduce vibrations.

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Design and Testing of a Punching-on-Film Precision Hole Seeder for Peanuts

Transactions of the ASABE ◽

10.13031/trans.13967 ◽

2020 ◽

Vol 63 (6) ◽

pp. 1685-1696

Author(s):

Jianming Kang ◽

Qiangji Peng ◽

Chunyan Zhang ◽

Ningning Zhang ◽

Huimin Fang

Keyword(s):

Vacuum Chamber ◽

Field Experiments ◽

Operating Principle ◽

Chamber Pressure ◽

List Type ◽

Study Results ◽

Irrigation Pipes ◽

Precision Hole ◽

Seed Metering Device ◽

Design And Testing

HighlightsThe designed precision seeder meets the agronomic requirements for on-film hole seeding.Influencing factors were found by studying the operating principle and key parameters.A response model was successfully built and verified by experiments.This study provides technical support for punching-on-film hole seeding technology.Abstract. To satisfy the agronomic requirements for punching-on-film precision seeding of peanuts, a precision hole seeder was designed in this study. The seeder can perform simultaneous functions of film mulching, film punching, pipe laying, precision hole seeding, and seed covering. The overall structure and operating principle of the device were analyzed, and its major components, including a seed-metering device, soil-covering roller, and drip irrigation pipes, were theoretically studied. To optimize the operating parameters and achieve favorable performance, a three-factor quadratic orthogonal test was performed to test the effects of the vacuum chamber pressure, advancing speed of the seeder, and height of the type hole boss on the seeding performance; the variance and range of the test results were analyzed accordingly. Through the field experiments, when the vacuum chamber pressure, advancing speed of the seeder, and height of the type hole boss were optimized to 7.5 kPa, 4.2 km h-1, 5.3 mm, respectively, the qualification index, re-seeding index, and miss-seeding index of the seeder were 92.7%, 3.8%, and 3.5%, respectively. Thus, the developed seeder satisfies the agronomic requirements, and the study results provide a technical reference for the punching-on-film precision seeding of peanuts. Keywords: Model, Peanut, Precision seeding of peanut, Punching-on-film hole, Seeder.

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Critical Period for Weed Control in Grafted and Nongrafted Watermelon Grown in Plasticulture

Weed Science ◽

10.1017/wsc.2018.76 ◽

2018 ◽

Vol 67 (2) ◽

pp. 221-228 ◽

Cited By ~ 1

Author(s):

Matthew B. Bertucci ◽

Katherine M. Jennings ◽

David W. Monks ◽

Jonathan R. Schultheis ◽

Frank J. Louws ◽

...

Keyword(s):

Weed Control ◽

Critical Period ◽

Field Experiments ◽

Citrullus Lanatus ◽

Weed Species ◽

Yellow Nutsedge ◽

Study Results ◽

Seedless Watermelon ◽

Common Purslane ◽

Weed Removal

AbstractField experiments determined the critical period for weed control (CPWC) in grafted and nongrafted watermelon [Citrullus lanatus(Thumb.) Matsum. & Nakai] grown in plasticulture. Transplant types included ‘Exclamation’ seedless watermelon as the nongrafted control as well as Exclamation grafted onto two interspecific hybrid squash (ISH) rootstocks, ‘Carnivor’ and ‘Kazako’. To simulate weed emergence throughout the season, establishment treatments (EST) consisted of two seedlings each of common purslane (Portulaca oleraceaL.), large crabgrass [Digitaria sanguinalis(L.) Scop.], and yellow nutsedge (Cyperus esculentusL.) transplanted in a 15 by 15 cm square centered on watermelon plants at 0, 2, 3, 4, and 6 wk after watermelon transplanting (WATr) and remained until the final watermelon harvest at 11 WATr. To simulate weed control at different times in the season, removal treatments (REM) consisted of two seedlings of the same weed species transplanted in a 15 by 15 cm square centered on watermelon plants on the same day of watermelon transplanting and allowed to remain until 2, 3, 4, 6, and 11 WATr, at which time they were removed. Season-long weedy and weed-free controls were included for both EST and REM studies in both years. For all transplant types, aboveground biomass of weeds decreased as weed establishment was delayed and increased as weed removal was delayed. The predicted CPWC for nongrafted Exclamation and Carnivor required only a single weed removal between 2.3 and 2.5 WATr and 1.9 and 2.6 WATr, respectively, while predicted CPWC for Kazako rootstock occurred from 0.3 to 2.6 WATr. Our study results suggest that weed control for this mixed population of weeds would be similar between nongrafted Exclamation and Exclamation grafted onto Carnivor. But the observed CPWC of Exclamation grafted onto Kazako suggests that CPWC may vary with specific rootstock–scion combinations.

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Snow Interception Modeling: Isolated Observations have led to Land Surface Models Lacking Appropriate Climate Sensitivities

10.22541/au.161443094.42414018/v1 ◽

2021 ◽

Author(s):

Jessica Lundquist ◽

Susan Dickerson-Lange ◽

Ethan Gutmann ◽

Tobias Jonas ◽

Cassie Lumbrazo ◽

...

Keyword(s):

Literature Review ◽

Land Surface ◽

Field Data ◽

Forest Cover ◽

Field Experiments ◽

Field Measurements ◽

Hydrologic Model ◽

Force Balance ◽

Liquid Form ◽

Study Results

When formulating a hydrologic model, scientists rely on parameterizations of multiple processes based on field data, but literature review suggests that more frequently people select parameterizations that were included in pre-existing models rather than re-evaluating the underlying field experiments. Problems arise when limited field data exist, when “trusted” approaches do not get reevaluated, and when processes fundamentally change in different environments. The physics and dynamics of snow interception by conifers, including both loading and unloading of snow, is just such a case. The most commonly used interception parameterization is based on data from four trees from one site, but field study results are not directly transferable between environments. The process varies dramatically between locations with relatively warmer versus colder winters. Here, we combine a comprehensive literature review with a model to demonstrate essential improvements to model representations of snow interception. We recommend that, as a first and essential step, all models include increased loading due to increased adhesion and cohesion when temperatures rise from -3 and 0°C. The commonly used parameters of a fixed maximum value for loading and an e-folding time for unloading are not supported by observations or physical understanding and are not necessary to reproduce observations. In addition to unloading based on physical processes, such as wind or canopy warming, all models must represent melting of in-canopy snow so that it can be unloaded in liquid form. As a second step, we propose field experiments across climates and forest types to investigate: a) a representation of the force balance between adhesion and cohesion versus gravity for both interception efficiency and rates of unloading, b) wind effects during and between storms, and c) lubrication when snow melts. For greatest impact, this framework requires dedicated field measurements. These processes are essential for models to accurately represent the impacts of dynamically changing forest cover and snow cover on both global albedo and water supplies.

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