Analysis of a bicyclist’s head injury in lateral and frontal impact using the human full-body model

2017 ◽  
Vol 231 (3) ◽  
pp. 220-231 ◽  
Author(s):  
Tso-Liang Teng ◽  
Cho-Chung Liang ◽  
Van-Hai Nguyen
Keyword(s):  
Brain Injuries ◽  
Tangential Velocity ◽  
Material Design ◽  
Normal Velocity ◽  
Test Procedures ◽  
Bicycle Helmets ◽  
General Terms ◽  
Impact Protection ◽  
The Impact ◽  
Full Body

Helmets reduce the frequency and severity of head and brain injuries resulting from bicycle crashes. To ensure that all bicycle helmets provide a certain level of effectiveness, helmets are required to satisfy certain standards of construction and material design before they can be sold in the market. Impact protection is the primary consideration of nearly every helmet standard. The general terms for a test for assessing impact protection involve shock absorption. A helmeted headform is dropped onto an anvil and the headform acceleration is measured. However, the test procedures of the existing standards do not properly assess the protection level of helmets against oblique impacts. To investigate bicycle helmets in a real accident scenario, this study simulated the full body of a bicyclist when free falling onto a road. This study considered the normal velocity (VN) of 5.66 m/s and tangential velocity (VT) values of 0, 5, and 10 m/s. Finite element analyses of helmet impact tests were conducted using LS-DYNA software. Moreover, the impact responses obtained using full-body and detached-headform models were compared under identical impact conditions. The analysis results obtained herein can be useful for evaluating helmet quality and guiding future developments in helmet innovation.

scholarly journals Hierarchical Morphology and Formation Mechanism of Collision Surface of Al/Steel Dissimilar Lap Joints via Electromagnetic Pulse Welding

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1468
Author(s):  
Puquan Wang ◽  
Daolun Chen ◽  
Yunqi Yan ◽  
Xinwei She ◽  
Bo Feng ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Electromagnetic Pulse ◽  
Weld Zone ◽  
Tangential Velocity ◽  
Lap Joints ◽  
Normal Velocity ◽  
Porous Structures ◽  
Pulse Welding ◽  
The Impact ◽  
Bonding Characteristics

The aim of this study was to characterize detailed microstructural changes and bonding characteristics and identify the formation mechanism of collision surface of Al6061–Q355 steel dissimilar welded joints via electromagnetic pulse welding (EMPW). The collision surface was observed to consist of five zones from the center to the outside. The central non-weld zone exhibited a concave and convex morphology. The welding-affected zone mainly included melting features and porous structures, representing a porous joining. The secondary weld zone presented an obvious mechanical joining characterized by shear plateaus with stripes. The primary weld zone characterized by dimples with cavity features suggested the formation of diffusion or metallurgical bonding. The impact-affected zone denoted an invalid interfacial bonding due to discontinuous spot impact. During EMPW, the impact energy and pressure affected the changes of normal velocity and tangential velocity, and in turn, influenced the interfacial deformation behavior and bonding characteristics, including the formation of micropores which continued to grow into homogeneous or uneven porous structures via cavitation, surface tension, and depressurization, along with the effect of trapped air.

Eating Out in the Nineteenth and Twentieth Centuries: Changes in Food and in Social Identities

2018 ◽  
Author(s):  
Christel Lane
Keyword(s):  
Twentieth Century ◽  
Social Identities ◽  
Rapid Urbanization ◽  
General Terms ◽  
Quality Of Food ◽  
Nineteenth And Twentieth Centuries ◽  
Eating Out ◽  
Gender And Nation ◽  
The Impact

This chapter examines the impact of rapid urbanization and industrialization on food and eating out. It draws attention to the growing standardization of food and, with greater class differentiation, to the growing diversity in eating-out venues. Class, gender, and nation are again used as lenses to understand the different eating-out habits and their symbolic significance. Towards the end of the twentieth century, pubs moved more fully towards embracing dining. However, the quality of food, in general terms, began to improve significantly only towards the end of the century, and hospitality venues also moved towards selling food from diverse national origins.

scholarly journals Numerical simulation of variable thermal conductivity on 3D flow of nanofluid over a stretching sheet

2020 ◽  
Vol 9 (1) ◽  
pp. 233-243 ◽  
Author(s):  
Nainaru Tarakaramu ◽  
P.V. Satya Narayana ◽  
Bhumarapu Venkateswarlu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stretching Sheet ◽  
Three Dimensional ◽  
Variable Thermal Conductivity ◽  
Normal Velocity ◽  
Transfer Coefficients ◽  
Similarity Transformations ◽  
Frictional Coefficients ◽  
The Impact

AbstractThe present investigation deals with the steady three-dimensional flow and heat transfer of nanofluids due to stretching sheet in the presence of magnetic field and heat source. Three types of water based nanoparticles namely, copper (Cu), aluminium oxide (Al2O3), and titanium dioxide (TiO2) are considered in this study. The temperature dependent variable thermal conductivity and thermal radiation has been introduced in the energy equation. Using suitable similarity transformations the dimensional non-linear expressions are converted into dimensionless system and are then solved numerically by Runge-Kutta-Fehlberg scheme along with well-known shooting technique. The impact of various flow parameters on axial and transverse velocities, temperature, surface frictional coefficients and rate of heat transfer coefficients are visualized both in qualitative and quantitative manners in the vicinity of stretching sheet. The results reviled that the temperature and velocity of the fluid rise with increasing values of variable thermal conductivity parameter. Also, the temperature and normal velocity of the fluid in case of Cu-water nanoparticles is more than that of Al2O3- water nanofluid. On the other hand, the axial velocity of the fluid in case of Al2O3- water nanofluid is more than that of TiO2nanoparticles. In addition, the current outcomes are matched with the previously published consequences and initiate to be a good contract as a limiting sense.

Pure Design Method for Aerofoils in Cascade

1969 ◽  
Vol 11 (5) ◽  
pp. 454-467 ◽  
Author(s):  
K. Murugesan ◽  
J. W. Railly
Keyword(s):  
Exact Solution ◽  
Velocity Distribution ◽  
Design Problem ◽  
Design Method ◽  
Tangential Velocity ◽  
Surface Velocity ◽  
Normal Velocity ◽  
Blade Design ◽  
Blade Shape

An extension of Martensen's method is described which permits an exact solution of the inverse or blade design problem. An equation is derived for the normal velocity distributed about a given contour when a given tangential velocity is imposed about the contour and from this normal velocity an initial arbitrarily chosen blade shape may be successively modified until a blade is found having a desired surface velocity distribution. Five examples of the method are given.

Footwear and Elevated Heel Influence On Barbell Back Squat: a Review

2021 ◽  
Author(s):  
Aaron Michael Pangan ◽  
Matthew J Leineweber
Keyword(s):  
Ground Reaction Forces ◽  
Specific Effects ◽  
Back Squat ◽  
Running Shoes ◽  
Different Types ◽  
Reaction Forces ◽  
Joint Loads ◽  
The Impact ◽  
Kinematics And Kinetics ◽  
Full Body

Abstract The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular clinical exercise during rehabilitation and was shown to provide similar effects to WLS. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to non-athlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

Designing the landscape for technological development in neonatal neurocritical care

2018 ◽  
Vol 4 (4) ◽  
pp. 163-171
Author(s):  
Colin Hamilton ◽  
Robert Phaal ◽  
Mita Brahmbhatt ◽  
Peter Jarritt ◽  
Topun Austin
Keyword(s):  
Real Time ◽  
Neurocritical Care ◽  
Brain Injuries ◽  
Unmet Needs ◽  
Technology Development ◽  
Clinical Skills ◽  
Technological Development ◽  
Newborn Infants ◽  
Patient Pathway ◽  
The Impact

ObjectivesTo identify current ‘gaps’ in clinical practice or therapeutic knowledge of the care of neonatal neurointensive care patients and to determine the impact healthcare technologies can have on improving outcomes.DesignThe Cambridge Institute for Manufacturing’s (IfM) roadmapping methodology.SettingCambridge, UK.Participants16 delegates were selected through professional networks. They provided coverage of academia and clinical skills, as well as expertise in neonatology, engineering and technology development.Main outcome measuresA ‘strategic landscape’ has been developed with ‘landmarks’ identified as ‘trends or drivers’, ‘patient pathway experience and unmet needs’ and ‘enabling project or resources’. Priorities were voted on by delegates.Results26 strategic ‘landmarks’ were identified, and of these 8 were considered ‘trends or drivers’, 8 ‘patient pathway experience and unmet needs’ and 10 as ‘enabling project or resources’. Of these, five priorities for the future of neonatal neurocritical care were identified by a voting process: real-time video monitoring for parents; individualised management of preterm infants in neonatal neurocritical care based on real-time multimodal monitoring; continuous electroencephalogram monitoring for early seizure diagnosis; neuroprotection: understanding basic mechanisms; and sleep measurement.ConclusionsThrough the use of the IfM methodology, a list of priorities has been developed for future work into improving the experience and possible outcomes of newborn infants with brain injuries and their families. While not an exhaustive list, it provides the beginning for a national conversation on the topic.

scholarly journals Risk compensation and bicycle helmets: a false conclusion and uncritical citations

2018 ◽  
Author(s):  
Igor Radun ◽  
Jenni Radun ◽  
Mahsa Esmaeilikia ◽  
Timo Lajunen
Keyword(s):  
General Public ◽  
Head Injuries ◽  
Experimental Studies ◽  
Research Area ◽  
Risk Compensation ◽  
Policy Makers ◽  
Bicycle Helmets ◽  
False Conclusion ◽  
Helmet Laws ◽  
The Impact

Some researchers and many anti-helmet advocates often state that because cyclists are wearing a helmet they feel safer and take more risks. This hypothesis - risk compensation – if true, would reduce, annul or even reverse the assumed benefits of helmets in reducing head injuries. Consequently, this hypothesis is often used to oppose mandatory helmet laws. In this article, we illustrate how one of the few studies that attempted to experimentally test the hypothesis in relation to bicycle helmets arrives at a false conclusion. As a result it is often cited as evidence of risk compensation. Given the lack of experimental studies in this research area, the impact of a single study in shaping the opinions of the general public and of policy makers can be significant.

scholarly journals The Archetype of the Trickster in the Writings of C.G. Jung

2020 ◽  
Vol 53 (3) ◽  
pp. 227-238
Author(s):  
Ilona Błocian
Keyword(s):  
Human Development ◽  
Development Process ◽  
The Unconscious ◽  
General Terms ◽  
The Impact ◽  
Individual Human

Jung dealt with the concept of the trickster archetype in many of his works. References to his interpretations of the impact of this archetype and the myths associated with this figure are also scattered in many places of his works devoted to various issues. The notion of the archetype is extremely complex in his grasp, and the ways of understanding it are evolving, similarly to the concept of the unconscious. These evolutions are related to the transition from the plan of patterns of individual human development, to the development of the species, to the recognition of the very patterns of the development of reality, so they contain references to the psychological, anthropological, and philosophical levels. According to Jung, the trickster archetype expresses –in the most general terms –the conflict of these patterns, which introduces a certain factor to the development process that is both disharmonizing and dynamizing at the same time.

scholarly journals The Effect of Cell Compression and Cathode Pressure on Hydrogen Crossover in PEM Water Electrolysis

2021 ◽  
Author(s):  
Agate Martin ◽  
Patrick Trinke ◽  
Markus Stähler ◽  
Andrea Stähler ◽  
Fabian Scheepers ◽  
...  
Keyword(s):  
Mass Transport ◽  
Cell Voltage ◽  
Water Electrolysis ◽  
Material Design ◽  
Operating Conditions ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Current Densities ◽  
Hydrogen Crossover ◽  
The Impact

Abstract Hydrogen crossover poses a crucial issue for polymer electrolyte membrane (PEM) water electrolysers in terms of safe operation and efficiency losses, especially at increased hydrogen pressures. Besides the impact of external operating conditions, the structural properties of the materials also influence the mass transport within the cell. In this study, we provide an analysis of the effect of elevated cathode pressures (up to 15 bar) in addition to increased compression of the membrane electrode assembly on hydrogen crossover and the cell performance, using thin Nafion 212 membranes and current densities up to 3.6 A cm-2. It is shown that a higher compression leads to increased mass transport overpotentials, although the overall cell performance is improved due to the decreased ohmic losses. The mass transport limitations also become visible in enhanced anodic hydrogen contents with increasing compression at high current densities. Moreover, increases in cathode pressure are amplifying the compression effect on hydrogen crossover and mass transport losses. The results indicate that the cell voltage should not be the only criterion for optimizing the system design, but that the material design has to be considered for the reduction of hydrogen crossover in PEM water electrolysis.

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