scholarly journals Evolution of mantis shrimp telson armour and its role in ritualized fighting

2019 ◽  
Vol 16 (157) ◽  
pp. 20190203 ◽  
Author(s):  
Jennifer R. A. Taylor ◽  
Nina I. Scott ◽  
Greg W. Rouse
Keyword(s):  
Comparative Analysis ◽  
Impact Resistance ◽  
High Impact ◽  
Mantis Shrimp ◽  
Impact Forces ◽  
Drop Tests ◽  
Impact Parameters ◽  
Ritualized Combat ◽  
Stiff Spring ◽  
The Impact

Mantis shrimp possess both formidable weapons and impact-resistant armour that clash during ritualized combat. The telson is one of few biological structures known to withstand the repeated high impact forces of smashing mantis shrimp strikes, and it is hypothesized that this pairing of armour and weapon is associated with the evolution of telson sparring. We carried out a comparative analysis of telson impact mechanics across 15 mantis shrimp species to assess if the telsons of sparring species (i) are consistently specialized for impact-resistance, (ii) are more impact-resistant than those of non-sparring species, and (iii) have impact parameters that correlate with body size, and thereby useful for assessment. Our data from ball drop tests show that the telsons of all species function like a stiff spring that dissipates most of the impact energy, but none of the measured impact parameters are correlated with the occurrence of sparring behaviour. Impact parameters were correlated with body mass for only some species, suggesting that it is not broadly useful for size assessment during ritualized fighting. Contrary to expectation, sparring mantis shrimp do not appear to have coevolved telson armour that is more robust to impact than non-sparring species. Rather, telson structure is inherently impact-resistant.

scholarly journals Main Factors for Understanding High Impacts on CSR Dimensions in the Finance Industry

2020 ◽  
Vol 12 (6) ◽  
pp. 2395 ◽  
Author(s):  
Belen Lopez ◽  
Alfonso Torres ◽  
Alberto Ruozzi ◽  
Jose Antonio Vicente
Keyword(s):  
Corporate Governance ◽  
Comparative Analysis ◽  
Qualitative Comparative Analysis ◽  
Financial Sector ◽  
High Impact ◽  
Financial Firms ◽  
Finance Industry ◽  
Corporate Social ◽  
High Degree ◽  
The Impact

The objective of this study is to explore empirically the dimensions that generate high impact in the finance industry to better understand its contribution from a Corporate Social Responsibility (CSR) perspective. We analyze data concerning impacts of finance sector firms certified by B Corp in order to identify the combinations that are necessary and/or sufficient to obtain a recognition of their high impact generation. The methodology followed to identify the impact dimensions is fsQCA, (fuzzy set Qualitative Comparative Analysis), a qualitative comparative analysis method applied to a sample of finance firms (n-181). The results indicate that financial sector firms exhibited four combinations focusing on different impact dimensions. Specifically, the first route indicates that a high degree of focus on customers and communities is sufficient to obtain a high impact score. The second path signals that the combination of the impacts on customers and corporate governance could lead to the same result, while in the third pathway the focus would be on the employees. Finally, the fourth route indicates that some financial firms focus strongly on their communities, corporate governance and their employees, but very weakly on the environmental dimension. Consequently, diverse combinations of CSR dimensions characterize financial sector contributions to impact generation and sustainable development.

scholarly journals Jumping with adhesion: landing surface incline alters impact force and body kinematics in crested geckos

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy E. Higham ◽  
Mara N. S. Hofmann ◽  
Michelle Modert ◽  
Marc Thielen ◽  
Thomas Speck
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Three Dimensional ◽  
Adhesive System ◽  
Vertical Surface ◽  
High Impact ◽  
Body Movements ◽  
Impact Forces ◽  
Landing Platform ◽  
The Impact

AbstractArboreal habitats are characterized by a complex three-dimensional array of branches that vary in numerous characteristics, including incline, compliance, roughness, and diameter. Gaps must often be crossed, and this is frequently accomplished by leaping. Geckos bearing an adhesive system often jump in arboreal habitats, although few studies have examined their jumping biomechanics. We investigated the biomechanics of landing on smooth surfaces in crested geckos, Correlophus ciliatus, asking whether the incline of the landing platform alters impact forces and mid-air body movements. Using high-speed videography, we examined jumps from a horizontal take-off platform to horizontal, 45° and 90° landing platforms. Take-off velocity was greatest when geckos were jumping to a horizontal platform. Geckos did not modulate their body orientation in the air. Body curvature during landing, and landing duration, were greatest on the vertical platform. Together, these significantly reduced the impact force on the vertical platform. When landing on a smooth vertical surface, the geckos must engage the adhesive system to prevent slipping and falling. In contrast, landing on a horizontal surface requires no adhesion, but incurs high impact forces. Despite a lack of mid-air modulation, geckos appear robust to changing landing conditions.

scholarly journals Solid–Liquid Composites with High Impact Resistance

2021 ◽  
Author(s):  
Miao Yu ◽  
Xiying Li ◽  
Pengyu Lv ◽  
Huiling Duan
Keyword(s):  
Energy Dissipation ◽  
High Speed ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Impact Resistance ◽  
High Impact ◽  
Strain Rates ◽  
Dynamic Impact ◽  
Solid Liquid ◽  
The Impact

AbstractSolid–liquid composites (SLCs) with novel thermal/electronic/mechanical properties imparted by programmable and functional liquid inclusions have attracted considerable research interest in recent years, and are widely used in smart electronics and soft robotics. The feasible application of SLCs requires that they exhibit excellent static physical properties as well as dynamic impact resistance to satisfy complex service conditions, such as drops and impacts. This paper examined the impact resistance of SLCs fabricated by using microfluidic 3D printing. The results of dynamic split-Hopkinson pressure bar (SHPB) tests showed that the performance of the fabricated SLCs improved in terms of energy dissipation and impact resistance compared with pristine materials. In case of dynamic impact in the strain rates ranging from 100 to $$400\,\hbox {s}^{-1}$$ 400 s - 1 , the SLC specimen deformed without fracture, and its energy dissipation was dominated by the viscosity of the liquid inclusions. For dynamic impact in the strain rates ranging from 500 to $$800\,\hbox {s}^{-1}$$ 800 s - 1 , the SLC specimen fractured and its energy dissipation was determined by the volume fraction of the liquid inclusions. Thus, the energy dissipation of the SLCs could be tuned by regulating the viscosity and volume fraction of the liquid inclusions to satisfy the requirements of protection against different strain rates. Furthermore, the process of fracture of the SLCs under the dynamic SHPB tests was recorded and analyzed by using a high-speed camera. The results showed that distributed liquid inclusions changed the paths of crack propagation to enhance energy dissipation in the SLCs. This study experimentally verified the enhancement in the energy dissipation of SLCs, and provided design strategies for developing multifunctional SLCs with high impact resistance.

Effects of Sb and Zn Addition on Impact Resistance Improvement of Sn-Bi Solder Joints

2013 ◽  
Vol 2013 (1) ◽  
pp. 000104-000108 ◽  
Author(s):  
Keishiro Okamoto ◽  
Kenji Nomura ◽  
Shuichi Doi ◽  
Toshiya Akamatsu ◽  
Seiki Sakuyama ◽  
...  
Keyword(s):  
High Temperature ◽  
Solder Joints ◽  
Impact Resistance ◽  
The Other ◽  
Joint Interface ◽  
Resistance Increase ◽  
Zn Addition ◽  
Drop Tests ◽  
The Impact ◽  
Resistance Improvement

We investigated the effect of adding Sb and Zn on improving the impact resistance of Sn-Bi solder joints. Sn-57Bi-0.5Sb-0.5Zn showed a better resistance property than did Sn-58Bi, Sn-57Bi-1Ag, and Sn-57.5Bi-0.5Sb against package drop tests. Sn-57Bi-0.5Sb-0.5Zn had a resistance increase of less than 10% even when annealed at 125 °C, and the other three had an increase of more than 200 %. It is thought that the fall-proof characteristic greatly improved because the formation of a brittle Bi rich layer was controlled by the existing Cu5Zn8 layer formed at the joint interface after high temperature soaking.

Quantitative Prediction of Impact Forces In Elastomers

1999 ◽  
Vol 121 (3) ◽  
pp. 294-304 ◽  
Author(s):  
Suresh Goyal ◽  
Ronald G. Larson ◽  
Charles J. Aloisio
Keyword(s):  
Rational Design ◽  
Quantitative Prediction ◽  
Impact Surface ◽  
Impact Forces ◽  
Wide Range ◽  
Elastomeric Materials ◽  
Drop Tests ◽  
Linear Viscoelastic ◽  
Viscoelastic Characteristics ◽  
The Impact

We measure the impact forces and deflections resulting from drop tests of a mass with a flat impact surface onto flat pads of various elastomeric materials, and show that the forces can be predicted quantitatively with no adjustable parameters by using a theory whose only inputs are the linear viscoelastic characteristics of the materials, measured in small-amplitude oscillatory deformations. The theory, which models the elastomer as a nonlinear neo-Hookean material, is accurate for several elastomeric solids including polyurethanes, polynorbomene, and poly-vinyl-chlorides (PVCs), over a wide range of impact velocities, masses, temperatures and pad thicknesses. Some steps are taken to extend the model to surfaces which are not flat. The application in mind is the rational design of elastomeric components in impact-tolerant portable electronic equipment.

scholarly journals IMPACT FORCE ANALYSIS ON WAVE DISSIPATING CONCRETE BLOCKS DURING ROCKING MOTION

2011 ◽  
Vol 1 (32) ◽  
pp. 44
Author(s):  
Jun Mitsui ◽  
Masato Yamamoto ◽  
Satoshi Noboru ◽  
Ichiro Nishiwaki
Keyword(s):  
Impact Velocity ◽  
Impact Force ◽  
Scale Effects ◽  
Force Analysis ◽  
Impact Forces ◽  
Concrete Blocks ◽  
Rocking Motion ◽  
Drop Tests ◽  
Properties Of Materials ◽  
The Impact

Breakage of wave dissipating concrete blocks occasionally occurs due to collision with other blocks during rocking motion under wave action. Therefore, an understanding of the impact forces induced by rocking blocks is important to solve this problem. The authors formulated impact forces using impact velocity, properties of materials, and dimensionless parameters depending on the shape of blocks to propose a theory to predict the magnitude of impact force. Fundamental drop tests using tetrapods were also conducted to confirm the proposed formula. Various sizes of blocks were used in the drop tests to reveal the scale effects. It is shown that predicted impact forces agree well with measured ones and that no scale effects concerning impact force seem to exist in the range of this study.

Corruption as “one‑stop‑shop”: theory and empirical analysis

2018 ◽  
pp. 32-51
Author(s):  
R. Yu. Kochnev ◽  
L. I. Polishchuk ◽  
A. Yu. Rubin
Keyword(s):  
Comparative Analysis ◽  
Business Environment ◽  
Enterprise Performance ◽  
Double Jeopardy ◽  
One Stop ◽  
The Commons ◽  
Public Production ◽  
Performance Project ◽  
The Impact ◽  
Sector Theory

We present the comparative analysis of the impact of centralized and decentralized corruption for private sector. Theory and empirical evidence point out to a “double jeopardy” of decentralized corruption which increases the burden of corruption upon private firms and weakens the incentives of bureaucracy to provide public production inputs, such as infrastructure. These outcomes are produced by simultaneous free-riding and the tragedy of the commons effects. The empirical part of the paper utilizes data of the Business Environment and Enterprise Performance project.

Assessment of small businesses activities in Ukraine

2019 ◽  
pp. 40-47
Author(s):  
Igor Ponomarenko ◽  
Kateryna Volovnenko
Keyword(s):  
Comparative Analysis ◽  
Statistical Analysis ◽  
Small Business ◽  
Small Businesses ◽  
Government Agencies ◽  
Small Enterprises ◽  
The Subject ◽  
Business Entities ◽  
The Impact ◽  
Micro Enterprises

The subject of the research is a set of approaches to the statistical analysis ofthe activities of small business entities in Ukraine, including micro-enterprises. The purpose of writing this article is to study of the features of functioningof small business entities in Ukraine. Methodology. The research methodology isto use a system-structural and comparative analysis (to study the change in thenumber of small enterprises by major components); monographic (when studyingmethods of statistical analysis of small businesses); economic analysis (when assessing the impact of small business entities on socio-economic phenomena andprocesses in Ukraine). The scientific novelty consists to determine the features ofthe functioning of small businesses in Ukraine in modern conditions. The influenceof the activities of the main socio-economic and political indicators on the activities of small enterprises in recent periods of time has been identified. It has beenestablished that there is flexibility in the development of strategies by small businesses in conditions of significant competition, which makes it possible to quicklyrespond to changing situations in specific markets. Conclusions. The use of acomprehensive statistical analysis of small businesses functioning in Ukraine willallow government agencies to develop a set of measures to optimize the activitiesof these enterprises, which ultimately will positively affect the strengthening oftheir competitiveness and will contribute to the growth of the national economicsystem.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

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