scholarly journals Influence of Mechanical Damage under Repeated Loading on the Resistance of Geogrids against Abrasion

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3544
Author(s):  
David Miranda Carlos ◽  
Filipe Almeida ◽  
José Ricardo Carneiro ◽  
Maria de Lurdes Lopes
Keyword(s):  
Visual Inspection ◽  
Building Materials ◽  
Mechanical Damage ◽  
Tensile Tests ◽  
Strength Reduction ◽  
Soil Reinforcement ◽  
Repeated Loading ◽  
Negative Effect ◽  
Potential Negative Effect ◽  
Reduction Factors

Geogrids are building materials widely used for soil reinforcement that can be affected by the action of many degradation agents throughout their service life. The potential negative effect of the degradation agents should be properly estimated and accounted for during the design phase. The main aim of this work was to study the influence of mechanical damage under repeated loading on the resistance of geogrids against abrasion. Three geogrids (one extruded and two woven) were exposed in isolation to mechanical damage under repeated loading and abrasion tests, followed by the successive exposure to both degradation tests. The damage suffered by the geogrids was evaluated by visual inspection and by tensile tests. Based on the changes found in tensile strength, reduction factors were determined. The reduction factors obtained directly from the successive exposure were compared to those resulting from a method in which the reduction factors obtained for the isolated effect of each degradation agent were multiplied. Results indicated that the abrasion process tended to be affected by a previous exposure to mechanical damage under repeated loading and that the multiplication of the reduction factors obtained for the isolated effects of the degradation agents may not correctly represent their combined effect.

scholarly journals Resistance of Geosynthetics against the Isolated and Combined Effect of Mechanical Damage under Repeated Loading and Abrasion

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3558
Author(s):  
Filipe Almeida ◽  
David Miranda Carlos ◽  
José Ricardo Carneiro ◽  
Maria de Lurdes Lopes
Keyword(s):  
Hydraulic Properties ◽  
Construction Materials ◽  
Mechanical Damage ◽  
Tensile Tests ◽  
Repeated Loading ◽  
Short Term ◽  
Engineering Structures ◽  
Wide Range ◽  
Materials Used ◽  
Reduction Factors

The behaviour of materials used for developing engineering structures should be properly foreseen during the design phase. Regarding geosynthetics, which are construction materials used in a wide range of engineering structures, the installation on site and the action of many degradation agents during service life may promote changes in their properties, endangering the structures in which they are applied. The evaluation of the damage suffered by geosynthetics, like installation damage or abrasion, is often carried out through laboratory tests. This work studied the behaviour of five geosynthetics (three geotextiles and two geogrids) after being individually and successively exposed to two degradation tests: mechanical damage under repeated loading and abrasion. The short-term mechanical and hydraulic behaviours of the geosynthetics were analysed by performing tensile tests and water permeability normal to the plane tests. Reduction factors were determined based on the changes occurred in the tensile strength of the geosynthetics. Findings showed that mechanical damage under repeated loading and abrasion tended to affect the mechanical and hydraulic properties of the geosynthetics and that the reduction factors calculated according to the traditional method may not be able to represent accurately the damage suffered by the materials when exposed successively to the degradation mechanisms.

Digital Pollution and Its Impact on the Family and Social Interactions

2021 ◽  
pp. 0192513X2098555
Author(s):  
Shiv Ratan Agrawal
Keyword(s):  
Social Interaction ◽  
Social Interactions ◽  
Critical Dimensions ◽  
Digital Devices ◽  
The Family ◽  
Negative Effect ◽  
Potential Negative Effect ◽  
Human Attitude ◽  
Impact On Family ◽  
And Behavior

The present study was an attempt to identify the most prevailing means of digital devices and its impact as digital pollution on family and social interactions. Despite the obvious benefits of digital devices, in recent years researchers have taken more concern about its potential negative effect on human attitude and behavior, which in turn affects our society. A total of 613 usable responses were collected from Bangalore, India of excessive users of digital devices, such as a smartphone, computer/laptop, and television. All statistical analyses were performed using SPSS 23.0, AMOS 23.0, and SmartPLS 3.0. The results indicated that as the use of smartphone and computer/laptop increases, levels of digital pollution also increase, which in turn significantly triggers unfavorable impact on family and social interactions. The study indicated that digital pollution appears as an important predictor, which significantly affects social interaction unfavorably. The present study explored the various critical dimensions within this domain and delineated gaps in our knowledge of digital pollution. It was found that smartphones are more responsible for digital pollution among all the identified digital devices, followed by computer/laptop.

scholarly journals Effect of Honey and Syrup Diets Enriched with 1,3-1,6 β-Glucans on Honeybee Survival Rate and Phenoloxidase Activity (Apis mellifera L. 1758)

2021 ◽  
Vol 8 (7) ◽  
pp. 130
Author(s):  
Simona Sagona ◽  
Baldassare Fronte ◽  
Francesca Coppola ◽  
Elena Tafi ◽  
Matteo Giusti ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Survival Rate ◽  
Significant Variation ◽  
Innate Immune ◽  
Control Group ◽  
Phenoloxidase Activity ◽  
Immune Modulators ◽  
Negative Effect ◽  
Potential Negative Effect ◽  
Combined Action

β-glucans can activate the animal innate immune system by acting as immune-modulators and inducing various stimulatory effects. The aim of this study was to investigate the effect of 1,3-1,6 β-glucans administered orally for 96 h on Apis mellifera workers (newly emerged and nurse bees). β-glucans were included in honey and syrup. Survival rate and phenoloxidase activity were measured. In both newly emerged and nurse bees, β-glucans supplementation did not affect survival rate (p > 0.05). Conversely, phenoloxidase activity was higher in both newly emerged bees (p = 0.048) and nurse bees (p = 0.014) fed with a honey diet enriched with β-glucans compared to those fed with only honey. In both the newly emerged and nurse bees, no statistical differences in phenoloxidase activity were recorded between the group fed with a syrup-based diet enriched with β-glucans and the control group (p > 0.05). The absence of significant variation in survival suggests that the potential negative effect of β-glucans in healthy bees could be mitigated by their metabolism. Conversely, the inclusion of β-glucans in a honey-based diet determined an increase of phenoloxidase activity, suggesting that the effect of β-glucan inclusion in the diet of healthy bees on phenoloxidase activity could be linked to the type of base-diet. Further investigations on β-glucans metabolism in bees, on molecular mechanism of phenoloxidase activation by 1,3-1,6 β-glucans, and relative thresholds are desirable. Moreover, investigation on the combined action of honey and β-glucans on phenoloxidase activity are needed.

NON-DESTRUCTIVE EVALUATION OF MECHANICAL DAMAGE OF ADHESIVES USING MAGNETO-ELECTRIC NANOPARTICLES

2021 ◽  
Author(s):  
GONZALO SEISDEDOS ◽  
BRIAN HERNANDEZ ◽  
JULIETTE DUBON ◽  
MARIANA ONTIVEROS ◽  
BENJAMIN BOESL ◽  
...  
Keyword(s):  
Adhesive Joint ◽  
Adhesive Bonding ◽  
Mechanical Damage ◽  
Adhesive Bond ◽  
Tensile Tests ◽  
Adhesive Joints ◽  
Adhesive Bonds ◽  
Magnetic Signatures ◽  
Looper System ◽  
Lock In

Adhesive bonding has been shown to successfully address some of the main problems with traditional fasteners, such as the reduction of the overall weight and a more uniformly distributed stress state. However, due to the unpredictability of failure of adhesive bonds, their use is not widely accepted in the aerospace industry. Unlike traditional fastening methods, it is difficult to inspect the health of an adhesive joint once it has been cured. For adhesive bonding to be widely accepted and implemented, there must be a better understanding of the fracture mechanism of the adhesive joints, as well as a way to monitor the health of the bonds nondestructively. Therefore, in-field structural health monitoring is an important tool to ensure optimal condition of the bond is present during its lifetime. This project focuses on the advancement of a non-invasive field instrument for evaluation of the health of the adhesive joints. The tool developed is based on a B-H looper system where coils are arranged into a noise-cancellation configuration to measure the magnetic susceptibility of the samples with a lock-in amplifier. The B-H looper system can evaluate the state of damage in an adhesive bond by detecting changes in surface charge density at the molecular level of an epoxy-based adhesive doped with magneto-electric nanoparticles (MENs). Epoxy-based adhesive samples were doped with MENs and then scanned using the B-H looper system. To evaluate the health of the adhesive joint, microindentation and tensile tests were performed on MENs-doped adhesive samples to understand the relationship between mechanical damage and magnetic signal. Correlations between magnetic signatures and mechanical damage were minimally observed, thus future studies will focus on refining the procedure and damaging methodology.

scholarly journals The effect of ecological growing on the potatoes yield and quality

2011 ◽  
Vol 51 (No. 9) ◽  
pp. 397-402 ◽  
Author(s):  
K. Hamouz ◽  
J. Lachman ◽  
P. Dvořák ◽  
V. Pivec
Keyword(s):  
Mechanical Damage ◽  
Field Trials ◽  
Matter Content ◽  
Point Of View ◽  
Nitrate Content ◽  
Dry Matter Content ◽  
Yield And Quality ◽  
Negative Effect ◽  
Cultivated Potatoes

In the years 1995–1997 the effect of ecological growing on the yield and selected parameters of quality of consumer potatoes (in comparison with conventional way) were investigated. The ecological way of growing differed in the lack of chemical protection against diseases and pests and industrial fertilizers. Field trials were realised with seven varieties (Impala, Karin, Agria, Korela, Rosella, Santé and Ornella) on two sites (Uhříněves and Valečov). The ecological way of growing had markedly negative effect on the yield (decrease by 36%). In qualitative parameters the ecological way increased inconclusively polyphenol content (by 10.2%), decreased inconclusively nitrate content (by 11.0%) and reducing sugars (by 22%). It did not affect dry matter content, resistance of tubers to mechanical damage, table value and glycoalkaloid content. Variety Santé achieved the best results from the point of view of the yield and majority of qualitative parameters among varieties. Qualitative parameters of ecologically cultivated potatoes were significantly affected by the year of cultivation.

The Legal and Regulatory Status of Biosimilars

2015 ◽  
Vol 41 (1) ◽  
pp. 49-84 ◽  
Author(s):  
Jordan Paradise
Keyword(s):  
Price Competition ◽  
Cost Savings ◽  
The United States ◽  
Current Debate ◽  
New Paradigm ◽  
State Laws ◽  
Patient Protection ◽  
Regulatory Status ◽  
Negative Effect ◽  
Potential Negative Effect

Alongside the constitutional controversy ultimately addressed by the Supreme Court, the colossal Patient Protection and Affordable Care Act (ACA) ushered in a new paradigm for regulation of biologics by the Food and Drug Administration (FDA). Nestled within the expansive ACA, the Biologics Price Competition and Innovation Act (BPCIA) set forth an abbreviated pathway to market for “biosimilar” and “interchangeable” biological products. While the current BPCIA implementation debate focuses chiefly on the scope of scientific and technical assessments by the FDA and the effect on the emergent biosimilar industry, two issues will prove essential for determinations of access to and costs of the resulting products: how the biosimilar and interchangeable biosimilar biologics are to be named, and whether pharmacist substitution is appropriate for products the FDA deems interchangeable. This article examines the current debate surrounding the use of nonproprietary names for biosimilar biologics, as well as state efforts to reconcile automatic substitution laws for the eventual products. In particular, the article addresses the implications for patients and the United States health care system, highlighting the potential negative effect on anticipated cost-savings, hindrances for effective tracking and reporting of adverse events, and a general lack of consistency in state laws.

The Environmental Impact of Coral Mining on Coral Reefs in the Maldives

1988 ◽  
Vol 15 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Barbara E. Brown ◽  
Richard P. Dunne
Keyword(s):  
Building Materials ◽  
Research Work ◽  
Mechanical Damage ◽  
Cost Effective ◽  
Reef Fishes ◽  
Living Coral ◽  
Biological Surveys ◽  
Concrete Blocks ◽  
Coral Rock ◽  
The Government

Demand of the construction industry for coral rock in the Maldives will soon reach the limit of supply capacity using existing collection techniques. It is estimated that, at the current rate of consumption, the supply of living coral rock from inner atoll ‘faros’ in North Malé will be exhausted within 30 years. Current mining practice has already necessitated the collection of living coral rock from outer atoll ‘faros’ which actually protect the integrity of the islands against the erosive influences of monsoon storms.Biological surveys of mined sites (compared with controls where no mining activity has taken place) indicate a dramatic reduction in coral variety and abundance and in some cases an almost total depletion of living coral after mining. At intensively-mined sites, diversity and abundance of coral-reef fishes is also markedly reduced, with some reef species commonly used as baitfish entirely absent. The time taken for reefs to recover from mechanical damage has been shown by other research work to be extremely variable, with some cases showing no recovery in some circumstances. Shallow-water reefs that have been colonized by slow-growing ‘massive’ corals, such as those which have been mined in the Maldives, may take a minimum of 50 years to recover to their former state—under optimum conditions.Observations on mined reefs in the Maldives show that recovery over the last 10 years has been minimal, and therefore suggest that recovery times may be much in excess of 50 years. Indeed many of these reefs may not recover at all unless some attempts are made to re-establish corals at these sites. It is also clear from the study of reclaimed and dredged sites and those where less-intensive mining has taken place, that regeneration of corals is occurring. It is quite probable that the rate of recovery is dependent on the intensity of the disturbance which initially took place.Alternative building materials are available in the form of concrete blocks. Use of these blocks is more cost-effective than use of coral rock; however, there is a lack of any quality control, which would be needed to promote the widespread use of concrete blocks as a substitute for coral. Recently, recommendations have been approved by the Government of Maldives for the execution of a feasibility study on mining an inner atoll faro which could potentially provide building material for as long as the next 500 years.

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