Microstructures and aerodynamics of commercial swimsuits

Procedia Engineering, 2011

Hydrodynamics plays an important role in swimming. Recently, swimsuits have been aggressively marketed, principally as a means for reducing the skin friction component of the total drag, thereby conferring a competitive advantage over other swimmers. Currently a range of swimsuits are available in the market however their aerodynamic data is hardly available in the public domain. Additionally, there is no standard methodology for the evaluation of hydrodynamic performance of swimsuits. The primary purpose of this work is to evaluate the hydrodynamic properties of a series of swimsuits at a macroscopic level. A standard cylindrical methodology has been developed in wind tunnel measurement of aero/hydrodynamic properties (drag and lift). Current production swimsuits including Diana and Spalding have been tested. All tests were conducted at a range of speeds. The findings indicate that there is a notable variation in aerodynamic properties among swimsuits.

Procedia Engineering, 2010

Swimsuit is believed to play an important role in swimmer's performance. In competitive swimming (national, world and Olympic events) it is usually a very short winning time margins that often requires the help of advanced technology to determine the time difference between the winner and loser. Almost over 90% of swimmer's energy is spent to overcome hydrodynamic resistance during forward motion. Hence, the swimsuits might play an important role in reducing the hydrodynamic resistance and its associated energy loss during the swimming and can contribute positively to the final outcome. Development of efficient swimsuits is an on going process and the performance of swimsuit is believed to be getting better progressively. Currently, swimsuit manufacturers spend huge resources to design swimsuits using new materials and techniques. Very often swimsuit manufacturers claim and counterclaim about the performance of the swimsuits. However, there is no independent study that can verify these claims and counter claims. This paper describes a hydrodynamics comparative evaluation of two commercially available swimsuits and their role that might be played in swimsuit aerodynamics.

Brazilian Archives of Biology and Technology, 2012

The purpose of this study was to analyse the effect of wearing a swimsuit on swimmer's passive drag. A computational fluid dynamics analysis was carried out to determine the hydrodynamic drag of a female swimmer's model (i) wearing a standard swimsuit; (ii) wearing a last generation swimsuit and; (iii) with no swimsuit, wearing light underwear. The three-dimensional surface geometry of a female swimmer's model with different swimsuit/underwear was acquired through standard commercial laser scanner. Passive drag force and drag coefficient were computed with the swimmer in a prone position. Higher hydrodynamic drag values were determined when the swimmer was with no swimsuit in comparison with the situation when the swimmer was wearing a swimsuit. The last generation swimsuit presented lower hydrodynamic drag values, although very similar to standard swimsuit. In conclusion, wearing a swimsuit could positively influence the swimmer's hydrodynamics, especially reducing the pressure drag component.

2009

Hydrodynamic resistance, also called water drag, is one of the most discussed issues in swimming sport and recognized as a major factor in terms of swimming performance. Different authors tried to demonstrate that body compression is responsible for a better result in swimming, ...

Journal of Southeast Asian Studies, 1999

Book review of "Inventing a Hero: The Posthumous Re-Creation of Andres Bonifacio. By Glenn Anthony May." Madison: University of Wisconsin Center for Southeast Asian Studies, 1996. Pp. xii, 200. Index.

Eric, 2019

Sociological effects of social media use The eruption of social media platforms such as Facebook, Twitter, Instagram, Whatsapp among others have had both positive and negative effects on their users. According to a research conducted by Urista, Dong and Day (2009), in the United States, over 80% of all internet users are on Facebook with almost a quarter of the population around the world also believed to be on this platform. Positively, social media has promoted diverse interactions among the people around the globe. This interaction has seen social media platforms experience rapid growth over the last few years. With interactions, through social media platforms, people have had diverse social benefits. People from diverse background, ethnicity and race have been encouraged by social media to cherish and form artificial relationship bonds over actual friendship. For example, through social media platforms, the patients have been able to meet and interact with their patients, teachers have been able to facilitate learning and further people have also been able to meet their spouses. In addition, people with marginal views are able to interact and meet each other over the social media platforms, fins one another, create publications and memes that bolster their worldview thus assisting them to break into the mainstream. Despite the positive effects of social media, the platforms also have negative sociological effects. According to Mehraj, Bhat & Mehraj (2014) without the existence of social media, the political, ethical and social ills experienced in our society today would have minimal visibility. Social media is currently promoting slacktivism as it kills real activism slowly. This is evident by the social media platforms contribution towards an increased awareness about societal awareness while little real change is being experienced. Social media has also brought about the issue of cyberbullying. According to a research conducted by Lowry, Zhang, Wang & Siponen (2016) the effect of social media on bullying have grown significantly with hundreds of people reporting the cases of cyberbullying from social media every day. Furthermore, many people around the world are misusing social media platforms to blackmail others, share video which brings about social issues and also spread of rumours. In addition, social media have also led to lack of privacy. Misuse of information, personal attacks, identity thefts and stalking are the most common threats that diverse users of social media platforms use. The information shared through social media spread fast around the world, by the time the posts or information is pulled down, it could have caused massive problems to the professional and personal lives of people. Social media platforms have also resulted in addiction and depression among their users. The social media has facilitated to young generation to over-analyze and criticize themselves and their own problems. Depression in the social media context means behaviour that users develop after spending much time on social media platforms such as Twitter, Snap chat, Whatsapp, Twitter and abruptly begin to demonstrate some symptoms of depression. Although, staying connected with peer is an essential aspect of social life, the social media intensity that demands constant engagement can create self-awareness factors and further might trigger depression in young generations. Due to online addition, when additions of social media are offline, they are likely to suffer social isolation, turn to restricted blogs and websites for them to stay online which in long run can result to social ills such as self-destructive and aggressive behaviours, unsafe sexual practices and substance abuse. Currently, social media has turned to be the main channel for young generation to vent current problems in their lives. For example, one a post is posted on social media, it can never be taken back, and although it can be deleted by the user it can be found anywhere else like other websites or screenshots on other devices. In addition, the post is also likely to receive negative comments which fuel depression and anxiety among the sender. Other sociological effects of social media include disability to think independently as people are influenced to think according to their online cycle or think according to majority rule. For example, people are fears to implement their own ideas due to fear of criticism from colleagues. This leads to low self-esteem. Other common effects include isolation, loneliness, suicidal, stress and anxiety. The personality of people who use/attracted to social media The personality of people who use and attracted to social media is combination of extravert and agreeableness. According to Zeichner (2019), extrovert is a personality type in psychology that describes a class of people who are sociable, assertive, draw energy from crowds, chatty and cheerful in their social interactions. Most of social media are extroverts meaning they are concerned with how other people, feel and feel. In addition, users are also quick to share their beliefs and ideas with other familiar or unfamiliar people through social media platforms. The users dislike impersonal analysis, sees everything from the human angle, interest in getting information of what going on around the world through feeds and some are very effective in leading group discussions and managing issues of others as expressed through social media.

Arktos Media, 2025

This book will be published by Arktos Media in 2025. Its subtitle is: Religion, Ethnicity, and Kingship: From Biblical Israel to the Post-Christian Collapse of British Race Patriotism. It is a collection of sixteen closely related essays which cross the disciplinary boundaries between history, politics, and theology. Together, they shed much-needed light on contemporary controversies surrounding the sometimes oxymoronic phenomenon of "Christian nationalism," past and present, as problem and as solution.

Disaster Mental Health , 2023

Springer proceedings in energy, 2023

This study focused on quantitative damage severity assessment in composite materials using Acousto-Ultrasonics (AU), an in-service and active nondestructive inspection technique in which Lamb waves are communicated through a damaged zone. This was done by activating a signal onto the composite material surface and acquiring the received waves after their interactions with the damage. It relied on early research that presented a series of stress wave factors (SWFs) derived from the frequency-domain of the AU data, as quantitative identifiers of the received signal. Although, the SWFs have previously been proven to determine the understanding of the spatial arrangements of the impact damage, the degree or severity of the damage inside the impact damage area has not been assessed. Therefore, the current research was a step in the right way toward that aim. AU waves were generated via a laminate with increasing concentrations of ply faults, across longitudinal length. The stress wave factors were first examined for an undamaged composite, and the SWFs were then connected with the fault concentration. The significance of the found linkages and the possible futures of quantitative assessment of the degree of damage by such relationships were examined. The stress wave factors showed clear and consistent patterns, as the fault concentration increased. With a rise in fault density, an element measuring the energy content of the waves significantly changed with R-sq(adj) = 91.33% and almost linearly, and provided a robust measurable trend, while other parameter exhibited lesser shifts with R-sq(adj) = 51.86%. The result obtained from the presented work provided a base to cost-effective and inservice measure to early detection of catastrophic failures in composite structures, including the wind turbine blades for renewable and sustainable energy generation.

Wear, 2019

effects of the ingredients of brake friction materials on friction and wear: A case study on phenolic resin and potassium titanate, Wear (2019), doi: