WorldWideScience

Sample records for sand volleyball rules

  1. NAGWS Volleyball Rulebook, 1993. Official Rules & Interpretations/Officiating.

    Science.gov (United States)

    1993

    The National Association for Girls and Women in Sport (NAGWS) Volleyball Rules are based on the United States Volleyball Rules, which in turn are adopted from the rules and interpretations of the International Volleyball Federation Rules. Following a foreword by Robertha Abney, NAGWS President, the publication is organized into six sections as…

  2. Volleyball Guide with Official Rules. July 1971 - July 1973.

    Science.gov (United States)

    Wilde, Jackie, Ed.

    This guide for playing women's volleyball dated July 1971 - July 1973 details rules and standards as well as the Division for Girls and Women's Sports (DGWS) statement of beliefs. Specific articles dealing with teamwork, basic fundamentals, suggestions for beginners, a volleyball mini unit, and volleyball visual aids are included. The booklet…

  3. The Changing Rules of the Game, Volleyball Player Systematic Structure and Effects in Applying

    Directory of Open Access Journals (Sweden)

    Özgür DİNÇER

    2015-08-01

    Full Text Available Purpose: We the purpose of this study, ranging from past to present and play volleyball rule changes that occur related to industry structure, how structure affects in applying with a systematic trial. Method: Volleyball, starting from the date of the present day sports entertainment, sport has become a subject performance. . As regards; the changing rules of the game, in terms of volleyball player systematic structure and effects on performance. The changing rules of the game, volleyball player systematic structure and effects the exhibition of the game, tactical understanding of the game is to combine the implementation of different systems to meet the needs of training and competition has created situations. Volleyball to purpose of changing the rules of the game, service, location and block combinations to improve defense, reducing the effect of conditions of service coverage and attack the ball to extend the duration of stay in the game. Thus, the visuals might volleyball, in terms of spectators and media will become attractive. While this study, scan was used during the research literature. Results: According to the data obtained from the literature, that the structural changes in the volleyball is thought to cause the positive and negative impact in the volleyball. Conclusion: Result of this research, the changing rules of the game affected the players' and the exhibition of the game and the diversity of training, volleyball game speed has increased, and became the focus of visual winning. The conclusion of every move made in the field with a number of players has increased and with it the responsibility of the importance of individual tactical exercises may have gained more importance.

  4. Biomechanical differences of arm swing countermovement jumps on sand and rigid surface performed by elite beach volleyball players.

    Science.gov (United States)

    Giatsis, George; Panoutsakopoulos, Vassilios; Kollias, Iraklis A

    2018-05-01

    The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p volleyball.

  5. Effects of Experimental Volleyball Rules Quantified by Type and Number of Jumps, Hits and Contacts

    Directory of Open Access Journals (Sweden)

    Mladen Stankovic

    2017-10-01

    Full Text Available The purpose of this study was to determine the influence of the two new rules tested at the inaugural U23 Men’s Volleyball World Championship (21-point set excluding the fifth set, and 15 seconds between rallies–10 seconds from the finished point until the referee’s whistle for serve and five seconds for performing the serve on number and types of jumps and number of contacts and hits. The analysis comprised 25,930 jumps (an essential physical activity for volleyball, 15,706 contacts and 10,224 hits during 36 matches played by 144 males aged under 23 at the first Under 23 Men’s World Championships organized in Uberlandia, Brazil, in 2013. Two investigations were conducted: 1 Analysis of jumps by Jump type, In-game role and Level of set win; 2 Analysis of contacts (reception, setting, block, defense and hits (serve and attack by Type, In-game role and Set outcome. Significant differences (p=0.000 were found between in-game role and jump type, as Middle blocker performed the most (34.7%, followed by Outside hitter (24.9%, Setter (24.6% and Opposite (15.8%. Significant differences were found for number and types of Hits between set Winner and Loser teams only for serves by Setter (p<0.001 and Middle blocker (p<0.05. The results showed major differences in jumps, hits and contacts between in-game roles: Middle blocker was the most frequent jumping position, followed by Outside hitter and Setter. The Libero showed a new tendency of being Setter with a jump after the initial Setter defense.

  6. Ecosystem-based design rules for marine sand extraction sites

    NARCIS (Netherlands)

    Jong, de Maarten F.; Borsje, Bas W.; Baptist, Martin J.; Wal, van der Jan Tjalling; Lindeboom, Han J.; Hoekstra, Piet

    2016-01-01

    The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch

  7. Ecosystem-based design rules for marine sand extraction sites

    NARCIS (Netherlands)

    de Jong, Maarten F.; Borsje, Bas W.; Baptist, Martin J.; van der Wal, Jan Tjalling; Lindeboom, Han J.; Hoekstra, Piet

    2016-01-01

    The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch

  8. Strategies for Competitive Volleyball.

    Science.gov (United States)

    Fraser, Stephen D.

    This book deals with strategies and team tactics involved in the game of volleyball. It is not intended to be an instructional book on how to execute the various skills required to play volleyball but instead endeavors to detail and explain basic tactics and strategies involved in volleyball team play. Each chapter deals with major areas of team…

  9. Volleyball. August 1975 - August 1977.

    Science.gov (United States)

    Polvino, Geri, Ed.

    This guide is part of a series published by the National Association for Girls and Women in Sport. It contains 16 articles written on various aspects of volleyball, such as (1) volleyball visual aids, (2) a volleyball bibliography, (3) training for volleyball, (4) key visual cues in volleyball, (5) basic agility for beginners, and (6) solving…

  10. Volleyball Scoring Systems.

    Science.gov (United States)

    Calhoun, William; Dargahi-Noubary, G. R.; Shi, Yixun

    2002-01-01

    The widespread interest in sports in our culture provides an excellent opportunity to catch students' attention in mathematics and statistics classes. One mathematically interesting aspect of volleyball, which can be used to motivate students, is the scoring system. (MM)

  11. Landing Techniques in Beach Volleyball

    Science.gov (United States)

    Tilp, Markus; Rindler, Michael

    2013-01-01

    The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ2(2) = 18.19, p volleyball revealed overall differences both in men (χ2(2) = 161.4, p volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key Points About 1/3 of all jumping actions in beach volleyball result in a landing on one foot. Especially following block situations men land on one foot more often than women. Landing techniques are related to different techniques and positions. Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150

  12. HAND INJURIES IN VOLLEYBALL

    NARCIS (Netherlands)

    BHAIRO, NH; NIJSTEN, MWN; VANDALEN, KC; TENDUIS, HJ

    We studied the long-term sequelae of hand injuries as a result of playing volleyball. In a retrospective study, 226 patients with injuries of the hand who were seen over a 5-year period at our Trauma Department, were investigated. Females accounted for 66 % of all injuries. The mean age was 26

  13. Comparative analysis of the physique of volleyball players selected from different volleyball clubs

    Directory of Open Access Journals (Sweden)

    Adrian Sieroń

    2017-12-01

    Full Text Available In recent years we have seen a steady increase in interest in sport among the public. This is due primarily to the deepening of knowledge about the health-promoting aspects for people who practice it regularly. Considerable interest primarily characterized by team games, which due to their accessibility, clearly defined rules, the variety of forms of movement, or finally, the interaction between human are the most popular sport disciplines. In Poland, one of the most popular team sports of football is next to volleyball. From year to year, this form of recreation is more and more supporters.  For many years, extremely important for researchers from around the world was to find the factors that determine the achievement of high results volleyball. This problem is steadily gaining in importance, because modern training methods contribute to maximizing the potential of each player. Many researchers believe that making attempts to find factors that are of potential players is one of the few areas where you can find the reserves to increase results. The aim of this study is to compare intergroup somatic athletes practicing volleyball, playing and trainees in four different teams in Lower Silesia. The study enrolled 54 men aged 12-15 years with a group of four volleyball players representing the same level of sports preparation. The study used data measuring 17 somatic features. The results show that the somatic features of individual players in all four teams are similar and homogeneous.

  14. LANDING TECHNIQUES IN BEACH VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Markus Tilp

    2013-09-01

    Full Text Available The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ²(2 = 18.19, p < 0.01 but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (χ²(2 = 161.4, p < 0.01 and women (χ²(2 = 84.91, p < 0.01. Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball

  15. Differentiating Experts' Anticipatory Skills in Beach Volleyball

    Science.gov (United States)

    Canal-Bruland, Rouwen; Mooren, Merel; Savelsbergh, Geert J. P.

    2011-01-01

    In this study, we examined how perceptual-motor expertise and watching experience contribute to anticipating the outcome of opponents' attacking actions in beach volleyball. To this end, we invited 8 expert beach volleyball players, 8 expert coaches, 8 expert referees, and 8 control participants with no beach volleyball experience to watch videos…

  16. Predicting Volleyball Serve-Reception

    NARCIS (Netherlands)

    Paulo, Ana; Zaal, Frank T J M; Fonseca, Sofia; Araujo, Duarte

    2016-01-01

    Serve and serve-reception performance have predicted success in volleyball. Given the impact of serve-reception on the game, we aimed at understanding what it is in the serve and receiver's actions that determines the selection of the type of pass used in serve-reception and its efficacy. Four

  17. Relationship between sitting volleyball performance and field fitness of sitting volleyball players in Korea

    Science.gov (United States)

    Jeoung, Bogja

    2017-01-01

    The purpose of this study was to evaluate the relationship between sitting volleyball performance and the field fitness of sitting volleyball players. Forty-five elite sitting volleyball players participated in 10 field fitness tests. Additionally, the players’ head coach and coach assessed their volleyball performance (receive and defense, block, attack, and serve). Data were analyzed with SPSS software version 21 by using correlation and regression analyses, and the significance level was set at Pvolleyball performance. PMID:29326896

  18. MOTIVES OF JUNIOR VOLLEYBALL PLAYERS TO START AND CONTINUE VOLLEYBALL AND THEIR EXPECTATIONS FOR THE FUTURE

    OpenAIRE

    BİNBOĞA, Meltem; KILIÇ, İbrahim; GÖKDEMİR, Kadir

    2013-01-01

    ABSTRACT The goal of this research is to analyze the reasons why junior volleyball players start and continue volleyball and their expectations from future. The study sample includes 359 sportsmen that have participated in the finals of Turkey Junior Volleyball championship in 2010-2011 volleyball seasons in Afyonkarahisar and Isparta cities. Data collection tool of the research is a survey made of three scales and personal features. Reliability analysis, frequency and percenta...

  19. Shaping decisions in volleyball An ecological approach to decision-making in volleyball passing

    NARCIS (Netherlands)

    Barsingerhorn, Annemiek D.; Zaal, Frank T. J. M.; De Poel, Harjo J.; Pepping, Gert-Jan

    2013-01-01

    To extend research on decision-making in sport we addressed the choices volleyball-players are faced with in a simple volleyball pass-return task. We manipulated the distance that eight experienced volleyball players had to cover for successful ball passing, and mapped their passing technique (i.e.,

  20. Postural Variables in Girls Practicing Volleyball

    Science.gov (United States)

    Grabara, Malgorzata; Hadzik, Andrzej

    2009-01-01

    Study aim: To assess body posture of young female volleyball players in relation to their untrained mates. Material and methods: A group of 42 volleyball players and another of 43 untrained girls, all aged 13-16 years were studied with respect to their body posture indices by using computer posturography. Spinal angles and curvatures were…

  1. Differentiating experts’ anticipatory skills in beach volleyball

    NARCIS (Netherlands)

    Canal Bruland, R.; Mooren, M.; Savelsbergh, G.J.P.

    2011-01-01

    In this study, we examined how perceptual-motor expertise and watching experience contribute to anticipating the outcome of opponents' attacking actions in beach volleyball. To this end, we invited 8 expert beach volleyball players, 8 expert coaches, 8 expert referees, and 8 control participants

  2. Menstrual cycle disorders in female volleyball players.

    Science.gov (United States)

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  3. Physical and technical demands of elite beach volleyball according to playing position and gender.

    Science.gov (United States)

    Natali, Simone; Ferioli, Davide; LA Torre, Antonio; Bonato, Matteo

    2017-12-01

    Beach volleyball is a team sport played by two teams of two players on a sand court divided by a net. To date, research has mainly focused on male beach volleyball players. Therefore, the aim of this study was to assess work-rest ratio and physical actions between males and females according to their role. Forty-two elite beach volley players (24 males and 18 females) were filmed during 12 beach volleyball matches of the Swatch Major Series 2016 of the beach volleyball World Tour in Poreč in (Croatia). Duration of point rallies, work rest ratio and the number of jumps and hits performed by the players according to their role (blockers and defenders) were recorded. Twenty-one teams (12 males and 9 females) were recorded during a total of 12 matches comprising 11 sets for males and 9 sets for females. Males scored a total of 428 points whereas females scored 440 points. Un-paired t-test did not show significant differences between males and females. Two-way analysis of variance showed a significant difference in the jumps performed between blockers and defenders and not between males and females. No significant differences in the other variables were detected. The present study provides new inside into female beach volleyball matches, giving preliminary normative data. Technical and physical aspects of beach volleyball performance appear not to be influenced by gender and to be only partially different according to playing positions. These results should be considered during the daily training scheduling.

  4. Upgrading model for the Volleyball teachers

    Directory of Open Access Journals (Sweden)

    Tania Rosa García Hernández

    2017-07-01

    Full Text Available The nowadays society in this XXI century influenced by the progressive development of technologies of information and communication and the knowledge management demands a creative man, transformer of the context in which he takes place, an individual who accepts the challenges of the modern society and that at the same time takes the best of this development. Meeting this goal, the higher education holds the mission of preparing in a continuous and permanent way to the professionals according to the activity they carry out, updating the knowledge in the science they work on. The sport professionals are not the exception in this endeavor due to the formative role they play in the society, it is also caused by the dynamics and the current competitions, the steady changes of the sport rules and the gradual improvement of the athlete’s performance, the venues equipment and the competition itself worldwide. This work is aimed at proposing an upgrading course for the Volleyball professionals in the sport formation school (EIDE Ormani Arenado Llonchimplemented through a strategy based on the difficulties taken from the application of the scientific methods which facilitate a viable, flexible and feasible outcome and with a high social meaning, as it contributes to rise the professional profile of the individuals involved in the study.

  5. Psycho-social attributes of elite African women volleyball players ...

    African Journals Online (AJOL)

    Psycho-social attributes of elite African women volleyball players. ... 78% of them were influenced by family members to play volleyball, 81% continued to play the game due to success, and 64% envisaged that ... AJOL African Journals Online.

  6. Training strategy of explosive strength in young female volleyball players

    Directory of Open Access Journals (Sweden)

    Ana Pereira

    2015-01-01

    Conclusions: The 8-week combined jump and ball throwing training can significantly improve muscular performance in young female volleyball players. These findings may be useful for all physical education teachers and volleyball coaches.

  7. Sports injuries in Plus League volleyball players.

    Science.gov (United States)

    Cieśla, E; Dutkiewicz, R; Mgłosiek, M; Nowak-Starz, G; Markowska, M; Jasiński, P; Dudek, J

    2015-06-01

    Although physical activity brings a range of lifelong health benefits, it may also lead to injuries that pose a significant threat to health. It is particularly noticeable in people involved in professional sports where sport-related injuries commonly occur and are associated with intense exercise which aims to improve physical fitness. The article attempts to determine incidence of sports injuries reported by Plus League volleyball players, as well as to identify their most common types and causes. The research project involved 90 Plus League volleyball players aged 18-37 with the average age of 25.11 (SD±5.378). A method of diagnostic survey was applied to collect empirical data by means of questionnaire developed by the authors (researchers). The results were statistically analysed and verified with the analysis of variance (ANOVA) and χ2 test at the significance level (or critical P-value) of P≤0.05. Over 87% of the respondents suffered from at least one sport-related injury. In total, 362 injuries occurred, on average 4.02 injuries per one volleyball player. The most common sports injuries involved ankle or talocrural joint (46 injuries), knee and lower leg muscles (30), interphalangeal articulations of fingers (30) as well as shoulder joint. More than half of the injuries (57%) occurred twice or three times. Volleyball players commonly sustain injuries through contact with an opposing player in competition. Sport-specific injuries may also occur due to exhaustion, lack of rest and undertreated injuries. The most common volleyball-related injuries are primarily talocrural joint, hand and shoulder injuries. Common types of injuries that can affect volleyball players include muscles, joints and ligaments injuries, sprains and strains as well as bruises. Most of these injuries are caused by exhaustion, contact with an opposing player during competition and fatigue. The incidence of sport-related injuries seems to be influenced by such factors as somatic

  8. EFFECTS OF WHOLE BODY VIBRATION ON STRENGTH AND JUMPING PERFORMANCE IN VOLLEYBALL AND BEACH VOLLEYBALL PLAYERS

    Science.gov (United States)

    Zmijewski, P.; Jimenez-Olmedo, J.M.; Jové-Tossi, M.A.; Martínez-Carbonell, A.; Suárez-Llorca, C.; Andreu-Cabrera, E.

    2014-01-01

    The primary aim of this study was to examine the effects of 6-week strength training with whole body vibration (WBV) on leg strength and jumping performance in volleyball and beach volleyball players. Twenty-three sub-elite male volleyball (VB; n=12) and beach volleyball players (BVB; n=11) aged 21.2±3.0 years were divided into two groups and subjected to 6 weeks of strength training (three one-hour sessions per week): (I) 12 players (6 VB and 6 BVB players) underwent training with WBV (30-40 Hz, 1.7-2.5 mm, 3.0-5.7 g), and (II) 11 players (6 VB and 5 BVB players) underwent traditional strength training. Squat jump (SJ) and countermovement squat jump (CMJ) measurements by the Ergo Tester contact platform and maximum leg press test (1RM) were conducted. Three-factor (2 time x 2 WBV use x 2 discipline) analysis of variance for SJ, CMJ and 1RM revealed a significant time main effect (pvolleyball and beach volleyball players increases leg strength more and leads to greater improvement in jump performance than traditional strength training, but greater improvements can be expected in beach volleyball players than in volleyball players. PMID:25187676

  9. Word play, ritual insult, and volleyball in Peru.

    Science.gov (United States)

    Perez, Justin

    2011-01-01

    Many gay men in the popular sectors of Lima, Peru participate in vóley callejero, or street volleyball. The ethnographic data presented in this article describes verbal and corporal mechanisms through which gay identity emerges within the particular context of the street volleyball game, ultimately highlighting the contextual nature of identity. The volleyball players are not just hitting a ball back and forth, they are engaging in a meaningful activity that illuminates intersections of language, sexuality, and identity. Through the manipulation of the street into a volleyball court, the volleyball players create a space conducive to the articulation of particular verbal and embodied practices that index gay identity. The challenge to the regulations of "proper" volleyball through the practice of ritual insulting and the cultivation of gay volleyball technique are playful reconfigurations of gendered practices prominent in the sites where fieldwork was carried out.

  10. [Dietary behaviours of volleyball and basketball players].

    Science.gov (United States)

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

    In sports, such as basketball and volleyball, players must demonstrate the speed, strength, stamina and concentration. Correct nutrition affects the strength of the muscles and the extension of capacity. It is also necessary for the proper functioning of the nervous system and determines the rate of regeneration after physical effort. The aim of this study was to assess dietary behaviours of professional volleyball and basketball players and compare the prevalence of correct behaviours in both groups. 209 professional volleyball and basketball players from sports clubs localized in six Silesian cities were survived with the mean of author questionnaire. The chi-square test was used to examine differences in the prevalence of the correct behaviours among players. Analysis of the results obtained showed that 52% of the players had 4-5 meals a day. 35% of respondents had wholemeal bread and/or groats daily. Milk and dairy products daily ate 71% of surveyed players, meat and sausages 70% respectively. 41% of respondents had cottage cheese and 28% had fish several times a week. Vegetables and fruit were eaten by 21% and respectively 23% of respondents. Sweets were eaten daily by 40% of surveyed, while fast-food were eaten several times a week by 17% of players. Nutrients for athletes were used by 32%, and vitamin supplementation by 48% of respondents. Prevalence of correct dietary behaviour in the group of professional volleyball and basketball players differed. Basketball players statistically more frequently than volleyball players had 4-5 meals a day, had wholemeal bread and/or thick groats, milk and dairy products, meat and sausages, especially poultry. They had raw vegetables and fruit several times a day. They drank more than 2.5 liters of fluids per day. They also significantly more frequently than volleyball players consumed the fast-food occasionally or never. Dietary behaviours of surveyed players were incorrect. Comparison of prevalence of proper behaviours

  11. Physics of volleyball: Spiking with a purpose

    Science.gov (United States)

    Behroozi, F.

    1998-05-01

    A few weeks ago our volleyball coach telephoned me with a problem: How high should a player jump to "spike" a "set" ball so it would clear the net and land at a known distance on the other side of the net?

  12. Modeling attacking of high skills volleyball players

    Directory of Open Access Journals (Sweden)

    Vladimir Gamaliy

    2014-12-01

    Full Text Available Purpose: to determine the model indicators of technical and tactical actions in the attack highly skilled volleyball players. Material and Methods: the study used statistical data of major international competitions: Olympic Games – 2012 World Championships – 2010, World League – 2010–2014 European Championship – 2010–2014. A total of 130 analyzed games. Methods were used: analysis and generalization of scientific and methodological literature, analysis of competitive activity highly skilled volleyball players, teacher observation, modeling technical and tactical actions in attacking highly skilled volleyball players. Results: it was found that the largest volume application of technical and tactical actions in the attack belongs to the group tactics «supple movement», whose indicator is 21,3%. The smallest amount of application belongs to the group tactics «flight level» model whose indicators is 5,4%, the efficiency of 3,4%, respectively. It is found that the power service in the jump from model parameters used in 51,6% of cases, the planning targets – 21,7% and 4,4% planning to reduce. Attacks performed with the back line, on model parameters used in the amount of 20,8% efficiency –13,7%. Conclusions: we prove that the performance of technical and tactical actions in the attack can be used as model in the control system of training and competitive process highly skilled volleyball players

  13. SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

    Directory of Open Access Journals (Sweden)

    GOH PIN SIANG

    2013-12-01

    Full Text Available The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to the Malaysian volleyball players throughout several volleyball tournament venues in Malaysia. The experiment will be conducted by comparing two groups of respondents, including volleyball players and non-volleyball players. This study is limited to several independent variables such as endorsement, advertising, pricing and electronic word-of-mouth. This study is significant for marketers for solving the challenges faced in the sport industry. It also helps to identify consumers’ purchase preferences for sport shoes. The marketer would understand more about their targeted customers’ intentions to purchase, thus the sport industry related with sport marketing in Malaysia might gain more profit.

  14. Fontainebleau Sand

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    2006-01-01

    The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

  15. Match Analysis in Volleyball: a systematic review

    Directory of Open Access Journals (Sweden)

    Miguel Silva

    2016-03-01

    Full Text Available The present article aims to review the available literature on match analysis in adult male Volleyball. Specific key words "performance analysis", "match analysis", "game analysis", "notational analysis", "tactical analysis", "technical analysis", "outcome" and "skills" were used to search relevant databases (PubMed, Web of Science, SportDiscus, Academic Search Complete and the International Journal of Performance Analysis in Sport. The research was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta analyses guidelines. Of 3407 studies initially identified, only 34 were fully reviewed, and their outcome measures extracted and analyzed. Studies that fit all inclusion criteria were organized into two levels of analysis, according to their research design (comparative or predictive and depending on the type of variables analyzed (skills and their relationship with success, play position and match phase. Results show that from a methodological point of view, comparative studies where currently complemented with some predictive studies. This predictive approach emerged with the aim to identify the relationship between variables, considering their possible interactions and consequently its effect on team performance, contributing to a better understanding of Volleyball game performance through match analysis. Taking into account the limitations of the reviewed studies, future research should provide comprehensive operational definitions for the studied variables, using more recent samples, and consider integrating the player positions and match phase contexts into the analysis of Volleyball.

  16. Study of attack in college volleyball

    Directory of Open Access Journals (Sweden)

    Yordan Portela Pozo

    2014-03-01

    This work is done in order to analyze the positive and negative aspects that affected the performance of the auction action in volleyball players performing this action (in this case male in the Provincial University Games in 2012 in Havana , for which I take as a case study to the players of the University of Information Sciences and its opponents in those games, completing a total of 268 shares auctions in 7 games with a total of 15 September analyzed taking account of changes in the sport of Volleyball university in Cuba, data recorded by an observation sheet previously completed by the authors. The main results in this paper show that the greatest amount of shots that were done in these games were diagonal and a good percentage of positive linear auctions however were few and with very poor results. The primary role of the auction for the game's success is fully confirmed in this work because this action is achieved through many points in the game of volleyball and thus leads to a better result.

  17. Relationship between landing strategy and patellar tendinopathy in volleyball

    NARCIS (Netherlands)

    Bisseling, Rob W.; Hof, At L.; Bredeweg, Steef W.; Zwerver, Johannes; Mulder, Theo

    Objective: The aetiology of patellar tendinopathy ( jumper's knee) remains unclear. To see whether landing strategy might be a risk factor for the development of this injury, this study examined whether landing dynamics from drop jumps differed among healthy volleyball players ( CON) and volleyball

  18. A one season prospective cohort study of volleyball injuries

    NARCIS (Netherlands)

    Verhagen, E.A.L.M.; van der Beek, A.J.; Bouter, L.M.; Bahr, R.; van Mechelen, W.

    2004-01-01

    Objective: To estimate the overall incidence of acute and overuse volleyball injuries, and to describe factors associated with ankle sprains. Methods: 486 players from the second and third Dutch national volleyball divisions participated in the study and were followed prospectively during a whole

  19. Evaluation of Game Performance in Elite Male Sitting Volleyball Players.

    Science.gov (United States)

    Molik, Bartosz; Morgulec-Adamowicz, Natalia; Marszałek, Jolanta; Kosmol, Andrzej; Rutkowska, Izabela; Jakubicka, Alicja; Kaliszewska, Ewelina; Kozłowski, Robert; Kurowska, Monika; Ploch, Elwira; Mustafins, Pavel; Gómez, Miguel-Ángel

    2017-04-01

    The aims of the current study were (a) to analyze the differences in game performances of sitting volleyball athletes representing the different types of disabilities and (b) to assess whether the seated position vertical reach is one of the crucial factors in the game performance level of sitting volleyball athletes. One hundred male athletes from various national teams participating in the European Championships in Sitting Volleyball (2009) took part in this study. The athletes were categorized according to type of disability and the results of the vertical reach in a seated position. Thirtysix games were analyzed using the Game Performance Sheet for Sitting Volleyball. Twenty-three game performance parameters were studied. In addition, the sum and effectiveness of attacks, blocks, block services, services, ball receiving, and defensive actions were calculated. The main results indicated significant differences between athletes with minimal disability and athletes with single amputations from above the knee in the level of defensive performances and the summation of defensive actions. There was also a significant difference between athletes in relation to their vertical reach during activity and attacking actions, blocks, and ball receiving. In addition, there were strong relationships between the players' vertical reach scores and their activity and effectiveness in sitting volleyball. In conclusion, the accuracy of the World Organization Volleyball for Disabled classification systems for sitting volleyball players was confirmed. There is a strong relationship between players' vertical reach and their effectiveness in sitting volleyball.

  20. [Muscular trunk stability in professional and amateur volleyball players].

    Science.gov (United States)

    Miltner, O; Siebert, C; Tschaepe, R; Maus, U; Kieffer, O

    2010-03-01

    The aim of this study was to analyse the efficiency of muscular activity in the trunk stabilisation of professional volleyball players compared to a group of amateur hobby players. The results were compared amongst the groups as well as with a reference group consisting of asymptomatic individuals. The question to be answered was whether or not professional volleyball players possess a characteristic strength profile in their trunk musculature and if differences exist with regard to the individuals' competitive playing level. In this comparative study 12 professional volleyball players (German Bundesliga) and 18 non-professional volleyball players were analysed with regard to their isometric strength profile in all three planes. The reference group was provided by the Proxomed company, which had previously analysed healthy untrained individuals (n = 1045) of various age groups. A sports-specific profile for the musculature of volleyball players revealed a significant reduction in the flexion and rotation strength as well as a well-developed lateral flexion strength (highly significant when compared to the reference group). With reference to the level played, better strength values in flexion and lateral flexion were found among the professional athletes. Professional volleyball players present with a characteristic trunk musculature strength profile. A detailed analysis of the muscle strength of the spine as part of a sports medicine work-up could prove helpful in preventing injuries and overuse problems in professional and hobby volleyball players.

  1. Strength asymmetry of the shoulders in elite volleyball players.

    Science.gov (United States)

    Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

    2014-01-01

    Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Descriptive laboratory study. A sample of 183 volleyball players (99 men, 84 women). We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk

  2. Validity, Reliability, and Sensitivity of a Volleyball Intermittent Endurance Test.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Medina-Carrillo, Javier; García-López, Juan; Morante, Juan C; Villa, José G; Foster, Carl

    2017-03-01

    To analyze the concurrent and construct validity of a volleyball intermittent endurance test (VIET). The VIET's test-retest reliability and sensitivity to assess seasonal changes was also studied. During the preseason, 71 volleyball players of different competitive levels took part in this study. All performed the VIET and a graded treadmill test with gas-exchange measurement (GXT). Thirty-one of the players performed an additional VIET to analyze the test-retest reliability. To test the VIET's sensitivity, 28 players repeated the VIET and GXT at the end of their season. Significant (P volleyball players.

  3. Methodological alternative for volleyball technic tactical preparation

    Directory of Open Access Journals (Sweden)

    Tania Rosa García Hernández

    2014-12-01

    Full Text Available At the moment, the humanity has travelled an impressive road. The man, that thousands of years ago used to obtain the existence means with primitive stone instruments that horrified him and used to invoke to God before any natural phenomenon, has penetrated in the world of the micro and macrocosms, and has created admirable works in all the aspects of the life. Besides, he has built and transformed many things in search of the truth and through the development of the science; however, the most important thing is that he has demonstrated that his creative possibilities and intellectuals are unlimited. The sport and the physical culture as part of the human creation have also to travel long road influenced by the development of the technology and the science. In order to contextualize these aspects we will go into the concepts of science and technology given by different authors. The present article offers a methodological alternative proposal for the improvement of the technical tactical evaluation of the volleyball base practitioners' during the process of training starting from a reorganization of the technical tactical indicators of the game, it has implicit the understanding of the structural elements of the volleyball game that allow to readjust in an integrated way the technical tactical elements for its evaluation during the process of training and its behaviour in the competition.

  4. A harmonic oscillator having “volleyball damping”

    Science.gov (United States)

    Mickens, R. E.; Oyedeji, K.; Rucker, S. A.

    2006-05-01

    Volleyball damping corresponds to linear damping up to a certain critical velocity, with zero damping above this value. The dynamics of a linear harmonic oscillator is investigated with this damping mechanism.

  5. SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

    OpenAIRE

    GOH PIN SIANG; ZURAIDAH SULAIMAN

    2013-01-01

    The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth) and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to...

  6. Alberta oil sands royalty regime

    International Nuclear Information System (INIS)

    Asgarpour, S.

    2004-01-01

    The long term objective of the Oil Sands Business Unit of Alberta Energy is to pave the way for Alberta's bitumen production to reach 3 million barrels per day by 2020. This presentation described the national government's role in resource development. It was emphasized that since the Crown is the owner of the oil sands resource, it would benefit by providing strategic leadership and by generating a larger royalty base. The oil sands fiscal regime was described with reference to generic royalty, risk sharing, investment, and project economics. Business rule principles were also outlined along with criteria for project expansions. Both upstream and downstream challenges and opportunities were listed. 4 figs

  7. Observational tool to evaluate technician-tactical behavior in volleyball athletes in the base sport areas of Pinar del Rio

    Directory of Open Access Journals (Sweden)

    Tania Rosa García-Hernández

    2014-08-01

    Full Text Available The volleyball, collective sport characterized by the cooperation-opposition in the obtaining of an ideal competitive performance level, has proven in the last decades a continuous and quick development based on the rules´ transformation that govern them; promoting changes in the methods and procedures trainings conception with reach that it consider the methodological systems for the technical and preparation tactics. The following research intend to search an own relevancy in the context of the initial formation and of the technical and tactical improvement in the high-performance levels that, it has the purpose to offer the volleyball trainers an evaluation tool to check the technician-tactical level of 10 and 12 years children in the base sport areas. In the same way, it hopes to contribute to the achievement of a bigger effectiveness in the technical-tactics evaluation in the initiation volleyball and to improve the theoretical - methodological conception of this evaluation component in the sportsman's preparation, as well as to incorporate instruments that provide it.

  8. Incidence, aetiology and prevention of musculoskeletal injuries in volleyball : A systematic review of the literature

    NARCIS (Netherlands)

    Kilic, O.; Maas, M.; Verhagen, E.; Zwerver, J.; Gouttebarge, V.

    2017-01-01

    Currently, there is no overview of the incidence and (volleyball-specific) risk factors of musculoskeletal injuries among volleyball players, nor any insight into the effect of preventive measures on the incidence of injuries in volleyball. This study aimed to review systematically the scientific

  9. Bridging the Gap in Volleyball. From Basic Instruction to Game Play.

    Science.gov (United States)

    Dawson, Linda; Polvino, Geri

    1982-01-01

    Using volleyball "mini games," which emphasize, one at a time, skills needed to play volleyball, helps students to develop skills needed to play. Mini games described are: (1) forearm pass; (2) overhand pass; (3) overhand pass; (4) overhand serve; (5) mini volleyball; and (6) alternate court set-up. (CJ)

  10. Incidence, aetiology and prevention of musculoskeletal injuries in volleyball: A systematic review of the literature

    NARCIS (Netherlands)

    Kilic, O.; Maas, M.; Verhagen, E.; Zwerver, J.; Gouttebarge, V.

    2017-01-01

    Currently, there is no overview of the incidence and (volleyball-specific) risk factors of musculoskeletal injuries among volleyball players, nor any insight into the effect of preventive measures on the incidence of injuries in volleyball. This study aimed to review systematically the scientific

  11. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    Science.gov (United States)

    Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

    1995-01-01

    OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. RESULTS--54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. CONCLUSIONS--Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball. PMID:8520333

  12. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    Science.gov (United States)

    Kujala, U M; Taimela, S; Antti-Poika, I; Orava, S; Tuominen, R; Myllynen, P

    1995-12-02

    To determine the acute injury profile in each of six sports and compare the injury rates between the sports. Analysis of national sports injury insurance registry data. Finland during 1987-91. 621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. 54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball.

  13. Prospective study of injury in volleyball players: 6 year results.

    Science.gov (United States)

    Pastor, M F; Ezechieli, M; Classen, L; Kieffer, O; Miltner, O

    2015-01-01

    The volleyball game has a high complexity and thus entails a lot of strain to the players. Due to this high and different training and competition strain comprehensive and individual training plans should be developed with competing training objectives in order to prevent injuries. The aim of the study was to analyse prospectively over six seasons the acute and overuse injuries of a German male professional volleyball team. The study included 34 male national league players from season the 2007/08 to 2012/13. All players received a sport medicine examination and a functional diagnosis before each season. Based on the results the players received an individual training plan. The players suffered 186 injuries. The prevalence of acute injuries was 1.94 per player and overuse injuries 0.64 per player. The incidence of acute injuries was 3.3/1000 h volleyball and overuse injuries 1.08/1000 h volleyball. The largest number of injuries was found in the spine. The players had most likely minor injuries. The players had significantly fewer injuries in their second season (1.92) than in their first season (3.25; p= 0.004). It could be concluded that volleyball is a sport with a relative low prevalence of injuries compared to other team sports. The prevalence of injury is 2.58 per player. Due to an injury a player dropped out 16.91 days per season. An individual training program seems to reduce the incidence of injury.

  14. The volleyball athlete's shoulder: biomechanical adaptations and injury associations.

    Science.gov (United States)

    Challoumas, Dimitrios; Stavrou, Antonio; Dimitrakakis, Georgios

    2017-06-01

    In volleyball, the dominant shoulder of the athlete undergoes biomechanical and morphological adaptations; however, definitive conclusions about their exact nature, aetiology, purpose and associations with shoulder injury have not been reached. We present a systematic review of the existing literature describing biomechanical adaptations in the dominant shoulders of volleyball players and factors that may predispose to shoulder pain/injury. A thorough literature search via Medline, EMBASE and SCOPUS was conducted for original studies of volleyball players and 15 eligible articles were identified. Assessment of study quality was performed using the STROBE statement. The reviewed literature supports the existence of a glenohumeral internal rotation deficit (GIRD) and a possible (and less pronounced) external rotation gain in the dominant vs. the non-dominant shoulder of volleyball athletes. Unlike other overhead sports, the GIRD in volleyball athletes appears to be anatomical as a response to the repetitive overhead movements and not to be associated with shoulder pain/injury. Additionally, the dominant shoulder exhibits muscular imbalance, which appears to be a significant risk factor for shoulder pain. Strengthening of the external rotators should be used alongside shoulder stretching and joint mobilisations, core strengthening and optimisation of spike technique as part of injury management and prevention programmes.

  15. Experiences of returning to elite beach volleyball after shoulder injury.

    Science.gov (United States)

    Bele, Sofie; Östenberg, Anna Hafsteinsson; Sjöström, Rita; Alricsson, Marie

    2015-08-01

    The purpose of this study was to examine beach volleyball players' experience regarding shoulder injury and how it affects their return to play. To achieve the research aims a qualitative design with semi-structured interviews had been conducted, five elite beach volleyball players, four men and one woman aged 27-42 participated in the study. All participants had suffered a severe shoulder injury, with absence from training and competing for at least 28 days. The findings of this study indicate that it is the individual's inner motivation, together with a clear goal and support from the community, family, teammate and coach that are the most important factors when going through rehabilitation and getting back to playing beach volleyball after a shoulder injury. All participants had been affected by their injury in some way; some of the participants had been affected in a positive way since they had become mentally stronger and had developed better volleyball technique after rehabilitation. The conclusions of this study indicate that there are three distinct factors that increase the chances of getting back to playing beach volleyball after shoulder injury; it is the players' self motivation, together with a clear goal and support from the community.

  16. Sand consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Spain, H H

    1965-01-21

    In a sand consolidation method in which there is injected a mixture of resin-forming liquids comprising an aryl-hydroxy low molecular weight compound, a water- soluble aldehyde, and a catalyst, an improvement is claimed which comprises diluting the resin-forming liquids with a diluent and with water so that the yield of the resin is sufficient to consolidate the sand particles with the minimum desirable pressure. The diluent may be mutually soluble in water and in the resin-forming liquids, and does not affect the setting time of the polymer. The aldehyde and the aryl-hydroxy compound may be in ratio of 5:1, and the diluent, methyl alcohol, is present in a ratio of 2:1 with reference to the water.

  17. METRIC TESTS CHARACTERISTIC FOR ESTIMATING JUMPING FOR VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Toplica Stojanović

    2008-08-01

    Full Text Available With goal to establish metric tests characteristics for estimating jumping for volleyball players, it was organized a pilot research on pattern of 23 volleyball players from cadet team and 23 students from high-school. For needs of this research four tests are valid for estimation, jump in block with left and right leg and jump in spike with left and right leg. Each test has been taken three times, so that we could with test-re test method determine their reliability, and with factor analysis their validity. Data were processed by multivariate analysis (item analysis, factor analysis from statistical package „Statistica 6.0 for windows“. On the results of research and discussion we can say that the tests had high coefficient of reliability, as well as factor validity, and these tests can be used to estimate jumping for volleyball players.

  18. Caffeinated energy drinks improve volleyball performance in elite female players.

    Science.gov (United States)

    Pérez-López, Alberto; Salinero, Juan José; Abian-Vicen, Javier; Valadés, David; Lara, Beatriz; Hernandez, Cesar; Areces, Francisco; González, Cristina; Del Coso, Juan

    2015-04-01

    The objective of this study is to determine the effects of a caffeine-containing energy drink on female volleyball players' performance. Thirteen elite female volleyball players ingested 3 mg·kg of caffeine with an energy drink or the same drink without caffeine (placebo drink) in a double-blind and randomized study. Then, participants performed the following: standing spike, jumping spike, spike jump, blocking jump, squat jump, countermovement jump, manual dynamometry, and the agility t-test. A simulated volleyball game was played, videotaped, and notated afterward. In comparison to the placebo drink, the ingestion of the caffeinated energy drink increased the ball velocity in the standing spike (19.2 ± 2.1 vs 19.7 ± 1.9 m·s, P = 0.023) and in the jumping spike (17.9 ± 2.2 vs 18.8 ± 2.2 m·s, P = 0.038) and the jump height in the squat jump (28.1 ± 3.2 vs 29.4 ± 3.6 cm, P = 0.028), countermovement jump (32.0 ± 4.6 vs 33.1 ± 4.5 cm, P = 0.018), spike jump (43.3 ± 4.7 vs 44.4 ± 5.0 cm, P = 0.025), and block jump (35.2 ± 5.1 vs 36.1 ± 5.1 cm, P = 0.044). Furthermore, the caffeinated energy drink decreased the time needed to complete the agility t-test (11.1 ± 0.5 vs 10.9 ± 0.3 s, P = 0.036). During the game, the volleyball actions categorized as successful were more frequent with the caffeinated energy drink (34% ± 9% vs 45% ± 9%, P volleyball players. Increased physical performance led to improved accuracy during an actual volleyball match.

  19. Training strategy of explosive strength in young female volleyball players.

    Science.gov (United States)

    Pereira, Ana; Costa, Aldo M; Santos, Patricia; Figueiredo, Teresa; João, Paulo Vicente

    2015-01-01

    The aim of this study was to examine the effect of an 8-week combined jump and ball throwing training program in the performance of upper and lower extremities among young female volleyball players of the high school. A total of 20 young female volleyball players playing at Scholar Sport in High School at the district level were divided in two groups: the experimental group (n=10; 14.0±0.0 years; 1.6±0.1 m; 52.0±7.0 kg and 20.7±2.4% body mass) and the control group (n=10; 13.8±0.4 years, 1.6±0.1 m; 53.5±4.7 kg and 20.3±1.7% body mass). The experimental group received additional plyometric and ball throwing exercises besides their normal volleyball practice. The control group underwent only their regular session of training. Strength performance in the experimental group significantly improved (medicine ball and volleyball ball throwing: P=0.00; and counter movement jump: P=0.05), with the improvement ranging from 5.3% to 20.1%. No significant changes in strength performance were observed in the control group (P>0.05). The 8-week combined jump and ball throwing training can significantly improve muscular performance in young female volleyball players. These findings may be useful for all physical education teachers and volleyball coaches. Copyright © 2015 Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  20. A Profile of Fitness Parameters and Performance of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Govind B. Taware

    2013-07-01

    Full Text Available Background: Ball games require comprehen-sive ability including physical, technical, men-tal and tactical abilities. Among them, physicalabilities of players exert marked effects on theskill of the players themselves and the tacticsof the team. Therefore players must have thephysical abilities to meet the demand of thesport. Volleyball is one of the most popularlyplayed games in the world. Unfortunately, thelevel of performance of the Indian volleyballplayers lags far behind the international stan-dards. Aim of the Study: The present study wasaimed to assess flexibility, muscular endurance,power and cardio-respiratory endurance of vol-leyball players and to compare the results withage matched controls. Also, to compare thefindings of the volleyball players with that ofthe international norms from the available lit-erature and to make some suggestions for theimprovement in their performance level. Ma-terial and Methods: The study was carried outin 40 male volleyball players aged between 17to 26 years and 40 ages matched male controls.Physical fitness parameters namely flexibility,muscular endurance, power and cardio-respi-ratory endurance were measured, data was ana-lyzed using unpaired ‘t’-test. Results: It was ob-served that all physical fitness parameters weresignificantly more in players as compared totheir aged-matched controls but when values ofthe subjects were compared to internationalstandards; our subjects were behind the recom-mended norms for the elite volleyball players.Conclusion: The volleyball players have moreadvantage of flexibility muscular endurance,power and cardio-respiratory endurance.

  1. Mineral sands

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper presents an outlook of the Australian mineral sand industry and covers the major operators. It is shown that conscious of an environmentally minded public, the Australian miners have led the way in the rehabilitation of mined areas. Moreover the advanced ceramic industry is generating exciting new perspectives for zircon producers and there is a noticeable growth in the electronic market for rare earths, but in long term the success may depend as much on environmental management and communication skills as on mining and processing skills

  2. Considerations on the constitutional type of the central hitter in volleyball

    Directory of Open Access Journals (Sweden)

    Sorin GRĂDINARU

    2017-03-01

    Full Text Available The last major volleyball men competition was within the London 2012 Summer Olympics, which gathered 12 volleyball teams thoroughly selected during trial tournaments. On this occasion, they recorded the evolution of all participants and supplied volleyball methodologists and technicians with data on the various aspects of volleyball game (physical, technical, and tactical. We aimed at establishing the defining elements of a central hitter parameter dynamics in this competition. The subjects of our research were central hitters of all the participating volleyball teams. We also identified central hitters of the “Universitatea” Timişoara men volleyball team. The mean central hitter is, according to the data collected by the specialists of the London 2012 Summer Olympics, 27.93 years old and 203.8 cm tall, and weighs 94 kg. The central hitters of the volleyball team of Russia had particular values in all studied parameters: this position is relevant for the potential of the team and for the high level of the game. The mean values of the studied parameters are relevant in establishing the final hierarchy (Russia, Brazil, and Italy. We found obvious differences between the mean values of these parameters in the men volleyball players participating in the London 2012 Summer Olympics and the men volleyball players of the “Universitatea” Timişoara volleyball team.

  3. Foot Posture and Patellar Tendon Pain Among Adult Volleyball Players

    NARCIS (Netherlands)

    de Groot, Reinier; Malliaras, Peter; Munteanu, Shannon; Payne, Craig; Morrissey, Dylan; Maffulli, Nicola

    Objective: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. Design: Observational study. Setting: Field-based study among competing athletes. Participants: Volleyball

  4. TRAUMATISM IN TRAINING PROCESS OF STUDENTS - VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    V.Ya. Kovalchuk

    2017-01-01

    Full Text Available Purpose: to analyze traumas in training process of students-volleyball players. Material: 42 students participated in the research. Students’ medical records were analyzed in the research. Results: with every year of study in university the quantity of traumas decreased. In 1st year students we found 10 traumas, in 4th year - 5. Ligament sprains are the most frequent kinds of traumas. In total we found 33.3%. Their main part covers ankle joint traumas. The reasons of them are bursts, stops, changes of movements’ direction. Rather frequents (30% are maims of knee and elbow joints, caused by falling down. The degree of joints’ injury is, as usually, negligible. The highest quantity of moderate and heavy traumas was among 1st year students (9 from 10 and 2nd year students (8 from 8. Conclusions: prophylaxis complex for prevention of volleyball traumas has been offered. Volleyball traumas’ prevention implies improvement methodic and technique of students-volleyball players’ training. The main reasons of traumatism are the following: non observation of sports training principles; poor organizational and logistical support of training process.

  5. Teaching Strategies for the Forearm Pass in Volleyball

    Science.gov (United States)

    Casebolt, Kevin; Zhang, Peng; Brett, Christine

    2014-01-01

    This article shares teaching strategies for the forearm pass in the game of volleyball and identifies how they will help students improve their performance and development of forearm passing skills. The article also provides an assessment rubric to facilitate student understanding of the skill.

  6. Tales of the Unexpected: Coping among Female Collegiate Volleyball Players

    Science.gov (United States)

    Holt, Nicholas L.; Berg, Kylie-Joy; Tamminen, Katherine A.

    2007-01-01

    The purpose of this study was to examine patterns of appraisal, coping, and coping effectiveness in sport. Ten players from a collegiate female volleyball team were interviewed on two occasions, first in the week before a provincial final playoff tournament and in the week following the tournament. Data were transcribed verbatim and subjected to…

  7. Effectiveness of the Call in Beach Volleyball Attacking Play

    Directory of Open Access Journals (Sweden)

    Künzell Stefan

    2014-12-01

    Full Text Available In beach volleyball the setter has the opportunity to give her or his hitter a “call”. The call intends that the setter suggests to her or his partner where to place the attack in the opponent’s court. The effectiveness of a call is still unknown. We investigated the women’s and men’s Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% of attacks. If the male players followed a given call, 63% of the attacks were successful. The success rate of attacks without any call was 55.8% and 47.6% when the call was ignored. These differences were not significant (χ2(2 = 4.55, p = 0.103. In women’s beach volleyball, the rate of successful attacks was 61.5% when a call was followed, 35% for attacks without a call, and 42.6% when a call was ignored. The differences were highly significant (χ2(2 = 23.42, p < 0.0005. Taking into account the findings of the present study, we suggested that the call was effective in women’s beach volleyball, while its effect in men’s game was unclear. Considering the quality of calls we indicate that there is a significant potential to increase the effectiveness of a call.

  8. Foot posture and patellar tendon pain among adult volleyball players.

    NARCIS (Netherlands)

    Groot, R. de; Malliaras, P.; Munteanu, S.; Payne, C.; Morrissey, D.; Maffulli, N.

    2012-01-01

    OBJECTIVE: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. DESIGN: Observational study. SETTING: Field-based study among competing athletes. PARTICIPANTS: Volleyball

  9. Analysis of Severe Injuries Associated with Volleyball Activities.

    Science.gov (United States)

    Gerberich, Susan Goodwin; And Others

    1987-01-01

    Evaluation of 106 persons treated for injuries related to volleyball revealed that nearly 90 percent of injuries were concentrated in the lower extremities. Knee injuries accounted for 59 percent of injuries and ankle injuries accounted for about 23 percent of injuries. The mechanisms of jumping, landing, or twisting upon impact were highly…

  10. Predicting stay/leave behavior among volleyball referees

    NARCIS (Netherlands)

    Van Yperen, N.W.

    1998-01-01

    This study aimed to predict stay/leave behavior among volleyball referees. The predictor variables reflect commitment aspects from the literature: attraction, perceived lack of alternatives, personal investments, and feelings of obligation to remain. Intent to quit was assumed to mediate the link

  11. Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys.

    Science.gov (United States)

    Zouch, Mohamed; Chaari, Hamada; Zribi, Anis; Bouajina, Elyès; Vico, Laurence; Alexandre, Christian; Zaouali, Monia; Ben Nasr, Hela; Masmoudi, Liwa; Tabka, Zouhair

    2016-01-01

    The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10-12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm(2)) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  12. Defence tactic in volleyball: the analysis of the results of the pedagogic supervising. The competitive activity of the volleyball players

    Directory of Open Access Journals (Sweden)

    A A Lobanov

    2009-06-01

    Full Text Available The article analyses the technical and tactical actions that are used by volleyball players of high qualification during the competition. Taking into account this information in the studying and training process contributes to the increase of its effectiveness.

  13. Pediatric volleyball-related injuries treated in US emergency departments, 1990-2009.

    Science.gov (United States)

    Pollard, Katherine A; Shields, Brenda J; Smith, Gary A

    2011-09-01

    This study describes the epidemiology of pediatric volleyball-related injuries treated in US hospital emergency departments. Data for children younger than 18 years obtained from the National Electronic Injury Surveillance System of the US Consumer Product Safety Commission from 1990 through 2009 were analyzed. An estimated 692 024 volleyball-related injuries to children younger than 18 years occurred during the study period. The annual number of injuries declined significantly by 23% during the study period; however, the annual injury rate remained unchanged, and the number of volleyball-related concussions/closed head injuries increased significantly. Upper (48%) and lower (39%) extremity injuries occurred most frequently, as did strains/sprains (54%). Contact with the net/pole was associated with concussions/closed head injury our findings indicate opportunities for making volleyball an even safer sport for children. Protective padding, complying with US volleyball standards, should cover all volleyball poles and protruding hardware to prevent impact-related injuries.

  14. THE DIFFERENCE BETWEEN TWO VOLLEYBALL TEAMS IN SOME ANTHROPOMETERIC AND MOTOR ABILITIS

    OpenAIRE

    Bahri Gjinovci; Valon Nikqi; Florian Miftari

    2014-01-01

    Introduction: In this research we are deal with two teams of the super league of Kosovo in volleyball. The goal of this study is to verify the differences between the two teams in volleyball in some anthropometric characteristics, basic motor skills and situational tests. Methods: For the realization of this research, there were included 12 volleyball player from the team KV “Prishtina" and 12 from the team KV "Universiteti AAB". There are applied 4 anthropometric variables (body weight, body...

  15. Physical and physiological attributes of female volleyball players--a review.

    Science.gov (United States)

    Lidor, Ronnie; Ziv, Gal

    2010-07-01

    The main objective of this article was to review a series of studies (n = 31) on physical attributes, physiological attributes, and on-court performances of female volleyball players. Empirical and practical knowledge emerging from studies on training-related issues in volleyball, such as body mass, fat-free mass, aerobic profile, strength, and agility and speed, should be integrated and applied when planning annual training programs for volleyball players. Based on our review, it was found that (a) players of a higher skill level are taller, somewhat heavier, and have higher vertical jump values than players of a lower level; (b) the aerobic profile of female volleyball players is similar to that of female basketball players; (c) ballistic resistance training can increase vertical jump values in female volleyball players; and (d) preseason conditioning should be conducted to prevent fatigue and reduced performance at the beginning of the season. Among the research concerns discussed in the article are that there is a lack data for on-court performance and time-motion analysis in female volleyball players and that more experimental/manipulative studies are needed to examine the effectiveness of different training programs on physiological attributes of female volleyball players. Two practical implications are suggested for volleyball and strength and conditioning coaches: (a) functional and nonfunctional overreaching should be carefully monitored when planning strength and conditioning programs, and (b) volleyball programs should include ballistic-type training.

  16. Kinanthropometric profile of Cuban women Olympic volleyball champions.

    Science.gov (United States)

    Carvajal, Wiliam; Betancourt, Hamlet; León, Sofia; Deturnel, Yanel; Martínez, Miriam; Echevarría, Ivis; Castillo, María Eugenia; Serviat, Noemí

    2012-04-01

    Athletes' kinanthropometric profiles are widely addressed in the scientific literature. Such profiles are particularly important in volleyball because absolute size contributes a significant percentage of total variance associated with athletic success. As in other team sports, volleyball players' kinanthropometric attributes correlate with the game's tactical demands. From 1992 through 2000, the Cuban women's volleyball team achieved top global performance, winning first place in three successive Summer Olympic Games. Describe the kinanthropometric profiles of Cuban women Olympic volleyball champions during 1992-2000 and compare these by position played. Measurements were taken of body composition, somatotype, proportionality and several anthropometric indicators in 41 Cuban women volleyball players, grouped by playing position. All were members of the national team that participated in the Summer Olympic Games in Barcelona (1992), Atlanta (1996) and Sydney (2000). Mean and standard deviations were calculated for all study variables. Analysis of variance was used to compare means for different positions for the variables weight; height; percent adipose, muscle and bone mass; body mass index; and muscle-to-bone ratio. Discriminant analysis was performed to identify anthropometric dimensions differentiating playing positions (center, spiker and setter), using pvolleyball players was balanced mesomorphic (2.7-3.6-2.9). Classified by position, centers (2.9-3.4-3.4) and spikers (2.8-3.6-2.9) presented an average mesomorphic-ectomorphic somatotype, and setters (2.6-3.7-2.6) were balanced mesomorphic. On assessing Somatotype Attitudinal Mean (SAM), centers and spikers showed more intrapositional homogeneity than that of setters. Centers were significantly taller (187.1±2.5 cm) than players in other positions. Centers' percent adipose tissue mass (28.9±2.7%) was significantly higher than that of setters (24.3±2.7%), who were leanest of all positions. The

  17. Transition I efficiency and victory in volleyball matches

    Directory of Open Access Journals (Sweden)

    Herbert Ugrinowitsch

    2014-03-01

    Full Text Available The present study investigated the correlation between Transition Iwith victory in volleyball matches. The 2002 South-American Youth Men's Championship was recorded and the Transition I was analyzed and classified as negative, null or positive. Results of the efficiency in Transition I was calculated using t test for independent samples and compared to the efficiency between teams during each set and matches. Spearman correlation assessed the relationship between efficiency in each set and results of the matches with the final ranking in the championship. The results showed that the winning teams exhibited higher efficiency in Transition I, as well as a positive relationship of higher efficiency in Transition I with all of their results. The higher efficiency in Transition I is related to victory in volleyball matches.

  18. Predicting Factors of Zone 4 Attack in Volleyball.

    Science.gov (United States)

    Costa, Gustavo C; Castro, Henrique O; Evangelista, Breno F; Malheiros, Laura M; Greco, Pablo J; Ugrinowitsch, Herbert

    2017-06-01

    This study examined 142 volleyball games of the Men's Super League 2014/2015 seasons in Brazil from which we analyzed 24-26 games of each participating team, identifying 5,267 Zone 4 attacks for further analysis. Within these Zone 4 attacks, we analyzed the association between the effect of the attack carried out and the separate effects of serve reception, tempo and type of attack. We found that the reception, tempo of attack, second tempo of attack, and power of diagonal attack were predictors of the attack effect in Zone 4. Moreover, placed attacks showed a tendency to not yield a score. In conclusion, winning points in high-level men's volleyball requires excellent receptions, a fast attack tempo and powerfully executed of attacks.

  19. Volleyball and emotional health of students of pedagogical university

    Directory of Open Access Journals (Sweden)

    Y.Y. Muskharina

    2013-07-01

    Full Text Available The features of valueological pedagogical influence of volleyball lessons on the emotional state of pedagogical university students. In the experiment involved 96 students aged 18-20 years. It was found that 72% of students feel the satisfaction of most emotional needs during the game, 86.4% indicate a bright splash of feelings and a sense of mutual aid during the game, 24% of students met the best friends among the players section. 89.3% of students say that skill, sense of humor, energy, example and support of teacher (trainer during exercise can affect the emotional state of the team and each student. Professional and personal qualities of the coach, to encourage students to employment volleyball positive impact on the physical, mental performance, improve attention, ability to work in a team, to overcome emotional stress, feelings of fatigue, improves emotional state of students.

  20. Assessment of mental training in improving performance serve in volleyball

    Directory of Open Access Journals (Sweden)

    José Maria Montiel

    2013-09-01

    Full Text Available This article aimed to investigate the effects of mental training on volleyball players service performance. Six male volleyball players aged from 18 to 25 years old of a team from the interior of São Paulo’s state were studied. The service performance was evaluated in three different championships of the same season. The services were scored in game situations at the same time of the intervention process. The measure means indicated service performance increased with the mental training practice, with more services performed correctly and less mistakes at the end of the intervention process. The mistakes dimished significantly from the baseline to the final of the intervention process and from the start of the intervention process to its final.

  1. Volleyball and emotional health of students of pedagogical university

    Directory of Open Access Journals (Sweden)

    Muskharina Y.Y.

    2013-06-01

    Full Text Available The features of valueological pedagogical influence of volleyball lessons on the emotional state of pedagogical university students. In the experiment involved 96 students aged 18-20 years. It was found that 72% of students feel the satisfaction of most emotional needs during the game, 86.4% indicate a bright splash of feelings and a sense of mutual aid during the game, 24% of students met the best friends among the players section. 89.3% of students say that skill, sense of humor, energy, example and support of teacher (trainer during exercise can affect the emotional state of the team and each student. Professional and personal qualities of the coach, to encourage students to employment volleyball positive impact on the physical, mental performance, improve attention, ability to work in a team, to overcome emotional stress, feelings of fatigue, improves emotional state of students.

  2. Morphological classification of novice female volleyball players

    Directory of Open Access Journals (Sweden)

    José António Ribeiro Maia

    2003-12-01

    Full Text Available The characteristics of physique have been the subject of several studies in sport sciences because high-level competitive sports place maximum demands on the physical constitution of players. Furthermore, the specifi c function performed by a player in a game may be related to a particular modality. The goals of this study were: (1 to describe and to compare, from a somatic point of view, the physiques of 71 female volleyball players at beginner levels A and B (aged 12-14 years; and (2 to identify the components of somatic structure that best differentiate the athletics by level of experience. In order to evaluate the players’ somatic structure,we performed 21 measurements including: weight and height, diameters, circumferences, upper and lower limb measurements and skinfolds thicknesses. Discriminant function analysis (DFA was used to identify the power of variables classifi cation. No difference was found in physique between level A and level B players. They were classifi ed by somatotype as mesomorphic endomorphs (A = 4.76 - 3.78 - 1.85; and B = 4.37 - 4.02 - 1.88. RESUMO As características morfológicas têm sido objeto de vários estudos em Ciências Desporto, pelo fato de o fenômeno do desporto de alta competição exigir o máximo da estrutura física dos atletas e pela expectativa da função que o atleta desempenha em jogo. O presente estudo teve como objetivo: (1 descrever e comparar, do ponto de vista somático, a estrutura morfológica de 71 atletas de voleibol do sexo feminino dos escalões de formação A e B (entre os 12 e 14 anos de idade; (2 identifi car os componentes da estrutura somática que melhor diferenciam as atletas de níveis distintos. Para a avaliação da estrutura somática das atletas foram efetuadas 21 avaliações, incluindo além do peso e altura, comprimento dos membros, perímetros, diâmetros e pregas de adiposidade subcutâneas. Com o intuito de verifi car o poder discriminatório das variáveis na

  3. Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players

    NARCIS (Netherlands)

    van de Pol, Daan; Alaeikhanehshir, Sena; Maas, Mario; Kuijer, P. Paul F. M.

    2016-01-01

    The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and

  4. The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force during Landing from Volleyball Block Jumps

    Science.gov (United States)

    Hughes, Gerwyn; Watkins, James; Owen, Nick

    2010-01-01

    The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis…

  5. An economic evaluation of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball

    NARCIS (Netherlands)

    Verhagen, E.A.L.M.; van Tulder, M.; van der Beek, A.J.; Bouter, L.M.; van Mechelen, W.

    2005-01-01

    OBJECTIVES: To evaluate the cost effectiveness of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball. METHODS: A total of 116 volleyball teams participated in this study which was carried out during the 2001-2002 volleyball season. Teams were randomly

  6. Physical performance and positional differences among young female volleyball players.

    Science.gov (United States)

    Paz, Gabriel A; Gabbett, Tim J; Maia, Marianna F; Santana, Haroldo; Miranda, Humberto; Lima, Vicente

    2017-10-01

    The purpose of this study was to investigate the association among anthropometric, physical performance parameters, and dynamic postural control attributes of young female volleyball athletes, and to determine if differences exist in these attributes according to playing position. Forty-three young female volleyball players participated in this study. Players were divided by position into hitters (N.=17), middle blockers (N.=8), setters (N.=10), and liberos (N.=8). Stature, body mass, vertical jump (VJ), peak power, horizontal jump (HJ), sit-and-reach (SRT), star excursion balance (SEBT), and agility (e.g. shuttle run and Illinois agility test) tests were assessed on non-consecutive days in randomized order. No difference was found between groups for SRT, peak power, VJ, and HJ (P≤0.05). Middle blockers and hitters were taller than setters (P≤0.05). Middle blockers were also taller than liberos (P=0.017). Significant differences were observed among groups for agility tests, with hitters significantly faster than setters (P=0.023) and middle blockers (P=0.037). In addition, liberos were significantly faster than setters (P=0.032) and middle blockers (P=0.046), during the Illinois agility test. No difference was observed between groups for reach distance scores in the SEBT. These results demonstrate important positional differences in agility measures of young female volleyball players. Coaches can use this information to determine the type of physical profile that is needed for specific positions and to design training programs to maximize strength, power, and neuromuscular development of young female volleyball athletes.

  7. Cardiovascular and Musculoskeletal Assessment of Elite US Volleyball Players.

    Science.gov (United States)

    Davis, Christopher K; Dyar, Dan A; Vargas, Lisa A; Grossfeld, Paul D

    2015-11-01

    The aim of this study was to characterize the cardiovascular and musculoskeletal systems of elite volleyball players, including aortic dimensions. Previous studies have shown that the upper limit of normal aortic sinus diameter for male and female athletes is 4 and 3.4 cm, respectively. Cross-sectional analysis. United States Olympic Volleyball Training Facility and Rady Children's Hospital San Diego. Seventy (37 male) members of the US national volleyball team. Athletes underwent evaluation that included medical and family histories, targeted physical examinations specifically focusing on abnormalities present in Marfan syndrome (MFS), and transthoracic echocardiograms. Cardiac chamber and great artery size, valve function, and coronary artery origins were assessed. Three male athletes (8%) had an aortic sinus diameter ≥4 cm, one of whom also had an ascending aorta >4 cm. Two female athletes (6%) had aortic sinus diameter ≥3.4 cm, and another had an ascending aorta of 3.4 cm. There were no other intracardiac or arterial abnormalities. Individual musculoskeletal characteristics of MFS were common among the athletes but not more frequent or numerous in those with aortic dilation. The prevalence of aortic root dilation in this population of athletes was higher than what has previously been reported in other similar populations. Further study is needed to determine whether these represent pathological changes or normal variations in tall athletes. This study adds to the existing knowledge base of athlete's heart, with specific attention to aortic dimensions in elite volleyball players. The data are relevant to similar athletes' medical care and to preparticipation cardiac screening in general.

  8. Y-balance normative data for female collegiate volleyball players.

    Science.gov (United States)

    Hudson, Christy; Garrison, J Craig; Pollard, Kalyssa

    2016-11-01

    The Lower Quarter Y Balance (YBT-LQ) Test performance varies depending on competitive level, sport, gender, and age; therefore, determining normative scores specific to a population may be helpful in identifying injury-risk thresholds and return-to-play criteria following an injury. The purpose of this study was to determine normative YBT-LQ scores by assessing a subset of female, Division I volleyball players. A descriptive analysis cohort study. Ninety healthy (19.6 ± 1.2 y/o), collegiate female volleyball players. YBT-LQ was measured in 3 distinct directions of anterior (ANT), posteromedial (PM) and posterolateral (PL) on both the dominant and non-dominant limbs. In addition, a one way ANOVA was performed to determine mean group differences of YBT-LQ dominant and non-dominant limb composite score across position. Baseline values for this population were 94.1 ± 6.6% on the dominant limb and 93.9 ± 6.2% on the non-dominant limb. There were no significant differences for YBT-LQ composite scores on dominant (P = 0.867) and non-dominant (P = 0.989) limbs between position. This study identified normative YBT-LQ composite scores for healthy, female, collegiate volleyball players. Participants performed similarly despite their position. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Lower Limb Neuromuscular Asymmetry in Volleyball and Basketball Players.

    Science.gov (United States)

    Fort-Vanmeerhaeghe, Azahara; Gual, Gabriel; Romero-Rodriguez, Daniel; Unnitha, Viswanath

    2016-04-01

    The primary objective of the present study was to evaluate the agreement between the dominant leg (DL) (determined subjectively) and the stronger leg (SL) (determined via a functional test) in a group of basketball and volleyball players. The secondary objective was to calculate lower limb neuromuscular asymmetry when comparing the DL vs the non-dominant leg (NDL) and the SL vs the weaker (WL) leg in the whole group and when differentiating by sex. Seventy-nine male and female volleyball and basketball players (age: 23.7 ± 4.5 years) performed three single-leg vertical countermovement jumps (SLVCJ) on a contact mat. Vertical jump height and an inter-limb asymmetry index (ASI) were determined. Only 32 (40%) of the subjects had a concordance between the perception of their dominant leg and the limb reaching the highest jump height. Using the DL as the discriminating variable, significant (pjump performance. Vertical jump asymmetry of 10-15% exists and this can be considered as a reference value for male and female basketball and volleyball players.

  10. Landing-related ankle injuries do not occur in plantarflexion as once thought: a systematic video analysis of ankle injuries in world-class volleyball.

    Science.gov (United States)

    Skazalski, Christopher; Kruczynski, Jacek; Bahr, Martin Aase; Bere, Tone; Whiteley, Rod; Bahr, Roald

    2018-01-01

    Ankle injuries are prevalent in elite volleyball and suggested to result from player contact at the net. Traditionally, ankle sprains are thought to happen in a plantarflexed position, but case studies suggest plantarflexion may not be involved. Describe the injury situations and mechanisms of ankle injuries in world-class volleyball based on systematic video analysis of injuries reported through the Fédération Internationale de Volleyball (FIVB) Injury Surveillance System. Videos of 24 injuries from major FIVB tournaments were included for analysis (14 men, 10 women). Five analysts reviewed the videos to determine specific situations and mechanisms leading to injuries. The majority of injuries occurred during two volleyball situations, blocking (n=15) and attacking (n=6). Injuries to blockers were the result of landing on an opponent (n=11) or teammate (n=4). Attacking injuries most frequently occurred when a back-row player landed on a front-row teammate (n=4 of 6). When landing on an opponent under the net, the attacker landed into the opponent's court in 11 of 12 situations but without violating the centre line rule. Injuries mostly resulted from rapid inversion without any substantial plantarflexion. The majority of injuries occur while blocking, often landing on an opponent. The attacker is overwhelmingly to blame for injuries at the net secondary to crossing the centre line. Injuries while attacking often result from a back-row player landing on a front-row teammate. Landing-related injuries mostly result from rapid inversion with the absence of plantarflexion. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Students' Game Performance Improvements during a Hybrid Sport Education-Step-Game-Approach Volleyball Unit

    Science.gov (United States)

    Araújo, Rui; Mesquita, Isabel; Hastie, Peter; Pereira, Cristiana

    2016-01-01

    The purpose of this study was to examine a hybrid combination of sport education and the step-game-approach (SGA) on students' gameplay performance in volleyball, taking into account their sex and skill-level. Seventeen seventh-grade students (seven girls, 10 boys, average age 11.8) participated in a 25-lesson volleyball season, in which the…

  12. High intensity training improves exercise performance in elite women volleyball players during a competitive season

    DEFF Research Database (Denmark)

    Purkhús, Elisabeth; Krustrup, Peter; Mohr, Magni

    2016-01-01

    Elite women volleyball players (n=25; age; 19±5 yrs, height; 171±7 cm, weight; 63±10 kg; means±SD) volunteered to participate in the study. They were randomized into a high intensity training group (HIT; n=13) and a control group (CON; n=12). In addition to the normal team training and games, HIT...... women volleyball players....

  13. Collaboration with Sport Psychologists as Viewed by Female Volleyball Junior Teams

    Science.gov (United States)

    Otrebski, Wojciech; Rutkowska, Katarzyna

    2008-01-01

    Study aim: To determine the need of female junior volleyball players to collaborate with a psychologist, considering previous sport career of those players. Material and methods: A group of 78 female volleyball players aged 14-17 years from 7 top Polish junior teams participated in the study. They were requested to fill questionnaires on their…

  14. Physical Fitness Profiles of Sitting Volleyball Players of the Turkish National Team

    Science.gov (United States)

    Yüksel, Mehmet Fatih; Sevindi, Tarik

    2018-01-01

    This research is conducted to determine the physical profiles of sitting volleyball players of the Turkish National Team. 12 male players from Turkish Sitting Volleyball National Team volunteered to participate in the study. The anthropometric measurements were taken over dominant extremity. In order to determine the physical features of the…

  15. How do we learn to "kill" in volleyball?: The role of working memory capacity and expertise in volleyball motor learning.

    Science.gov (United States)

    Bisagno, Elisa; Morra, Sergio

    2018-03-01

    This study examines young volleyball players' learning of increasingly complex attack gestures. The main purpose of the study was to examine the predictive role of a cognitive variable, working memory capacity (or "M capacity"), in the acquisition and development of motor skills in a structured sport. Pascual-Leone's theory of constructive operators (TCO) was used as a framework; it defines working memory capacity as the maximum number of schemes that can be simultaneously activated by attentional resources. The role of expertise in motor learning was also considered. The expertise of each athlete was assessed in terms of years of practice and number of training sessions per week. The participants were 120 volleyball players, aged between 6 and 26 years, who performed both working memory tests and practical tests of volleyball involving the execution of the "third touch" by means of technical gestures of varying difficulty. We proposed a task analysis of these different gestures framed within the TCO. The results pointed to a very clear dissociation. On the one hand, M capacity was the best predictor of correct motor performance, and a specific capacity threshold was found for learning each attack gesture. On the other hand, experience was the key for the precision of the athletic gestures. This evidence could underline the existence of two different cognitive mechanisms in motor learning. The first one, relying on attentional resources, is required to learn a gesture. The second one, based on repeated experience, leads to its automatization. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Previously identified patellar tendinopathy risk factors differ between elite and sub-elite volleyball players.

    Science.gov (United States)

    Janssen, I; Steele, J R; Munro, B J; Brown, N A T

    2015-06-01

    Patellar tendinopathy is the most common knee injury incurred in volleyball, with its prevalence in elite athletes more than three times that of their sub-elite counterparts. The purpose of this study was to determine whether patellar tendinopathy risk factors differed between elite and sub-elite male volleyball players. Nine elite and nine sub-elite male volleyball players performed a lateral stop-jump block movement. Maximum vertical jump, training history, muscle extensibility and strength, three-dimensional landing kinematics (250 Hz), along with lower limb neuromuscular activation patterns (1500 Hz), and patellar tendon loading were collected during each trial. Multivariate analyses of variance (P volleyball players. Interventions designed to reduce landing frequency and improve quadriceps extensibility are recommended to reduce patellar tendinopathy prevalence in volleyball players. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Vortex-induced dynamic loads on a non-spinning volleyball

    Science.gov (United States)

    Qing-ding, Wei; Rong-sheng, Lin; Zhi-jie, Liu

    1988-09-01

    An experiment on vortex-induced dynamic loads on a non-spinning Volleyball was conducted in a wind tunnel. The flow past the Volleyball was visualized, and the aerodynamic load was measured by use of a strain gauge balance. The separation on the Volleyball was measured with hot-film. The experimental results suggest that under the action of an unstable tail vortex system the separation region is changeable, and that the fluctuation of drag and lateral forces is the same order of magnitude as the mean drag, no matter whether the seam of the Volleyball is symmetric or asymmetric, with regard to the flow. Based on the experimental data a numerical simulation of Volleyball swerve motion was made.

  18. Biomotor status and kinesiological education of girls aged 10 to 12 years--example: volleyball.

    Science.gov (United States)

    Milić, Mirjana; Grgantov, Zoran; Katić, Ratko

    2012-09-01

    The aim of this study was to define processes of orientation and/or selection towards sports game of volleyball in schoolgirls of Kastela, aged 10-12, by examining the relations between regular classes of physical education (PE) and extracurricular sport activities. For this purpose, two morphological measures were used (body height and body mass) and a set of 11 motor tests (6 basic motor abilities tests and 5 motor achievement tests) on a sample of 242 girls aged 10-12 was used, divided into a subsample of 42 girls participating in volleyball training (Volleyball players) and a subsample of 200 girls who do not participate in volleyball training (volleyball non-players). Based on the comparison of test results of schoolgirls from Kastela and Croatian norms, factor analysis of applied variables and discriminant analysis of these variables between volleyball players and non-players, processes and/or phases of selection in forming quality volleyball players were defined. Selection processes are preceded by orientation processes in physical education classes, i.e. choosing those sport activities which are in accordance with the biomotor status of students. Results have shown that orientation and initial selection in female volleyball needs to be executed based on the motor set of psychomotor speed, repetitive strength of the trunk and flexibility (muscle tone regulation), and body height. Volleyball training has affected the muscle mass development and the development of strength factors, so that explosive strength of jumping and/or takeoff along with body height, has predominantly differentiated female volleyball players from non-players, aged 10 to 12, and serve and spike quality will have dominant influence on the match outcome.

  19. A simple method for quantifying jump loads in volleyball athletes.

    Science.gov (United States)

    Charlton, Paula C; Kenneally-Dabrowski, Claire; Sheppard, Jeremy; Spratford, Wayne

    2017-03-01

    Evaluate the validity of a commercially available wearable device, the Vert, for measuring vertical displacement and jump count in volleyball athletes. Propose a potential method of quantifying external load during training and match play within this population. Validation study. The ability of the Vert device to measure vertical displacement in male, junior elite volleyball athletes was assessed against reference standard laboratory motion analysis. The ability of the Vert device to count jumps during training and match-play was assessed via comparison with retrospective video analysis to determine precision and recall. A method of quantifying external load, known as the load index (LdIx) algorithm was proposed using the product of the jump count and average kinetic energy. Correlation between two separate Vert devices and three-dimensional trajectory data were good to excellent for all jump types performed (r=0.83-0.97), with a mean bias of between 3.57-4.28cm. When matched against jumps identified through video analysis, the Vert demonstrated excellent precision (0.995-1.000) evidenced by a low number of false positives. The number of false negatives identified with the Vert was higher resulting in lower recall values (0.814-0.930). The Vert is a commercially available tool that has potential for measuring vertical displacement and jump count in elite junior volleyball athletes without the need for time-consuming analysis and bespoke software. Subsequently, allowing the collected data to better quantify load using the proposed algorithm (LdIx). Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  20. Superolateral Hoffa's Fat Pad Edema in Collegiate Volleyball Players.

    Science.gov (United States)

    Mehta, Kaushal; Wissman, Robert; England, Eric; Dʼheurle, Albert; Newton, Keith; Kenter, Keith

    2015-01-01

    Superolateral Hoffa's fat pad (SHFP) edema is a previously described magnetic resonance (MR) finding located between the patellar tendon and the lateral femoral condyle. The purpose of our study was to determine the prevalence and clinical significance of SHFP edema in female collegiate volleyball players. Sixteen female collegiate volleyball players were consented for bilateral knee evaluations which consisted of history, physical examination and MR imaging. Each MR study was reviewed for the presence of SHFP edema, and 6 patellar maltracking measurements were done. These were tibial tuberosity-trochlear groove distance, patellar translation, lateral patellofemoral angle, trochlear depth, trochlear sulcus angle, and lateral trochlear inclination angle. A total of 16 athletes, 32 knees (16 girls; age range, 18-22 years; mean, 19.9) were enrolled in the study. Sixteen knees (50%) in 8 athletes had SHFP edema, with 100% bilaterality; 16 knees in 8 athletes had no evidence of SHFP edema (50%). Functional outcomes and physical examination findings were within normal limits for all athletes with no difference noted between SHFP edema-positive and -negative individuals. There was a statistically significant difference in the tibial tuberosity-trochlear groove distance, patellar translation, and patellofemoral angle (P value of volleyball athletes have a very high prevalence of SHFP edema, which is always bilateral. Although the exact etiology of SHFP edema remains inconclusive, it could potentially be a sensitive indicator of subtle patellar maltracking which cannot be distinguished by history and physical examination findings. Given the very high prevalence of SHFP edema and this being an asymptomatic finding, there is likely little clinical significance of this in majority of high-performance athletes.

  1. Lower Limb Neuromuscular Asymmetry in Volleyball and Basketball Players

    Directory of Open Access Journals (Sweden)

    Fort-Vanmeerhaeghe Azahara

    2016-04-01

    Full Text Available The primary objective of the present study was to evaluate the agreement between the dominant leg (DL (determined subjectively and the stronger leg (SL (determined via a functional test in a group of basketball and volleyball players. The secondary objective was to calculate lower limb neuromuscular asymmetry when comparing the DL vs the non-dominant leg (NDL and the SL vs the weaker (WL leg in the whole group and when differentiating by sex. Seventy-nine male and female volleyball and basketball players (age: 23.7 ± 4.5 years performed three single-leg vertical countermovement jumps (SLVCJ on a contact mat. Vertical jump height and an inter-limb asymmetry index (ASI were determined. Only 32 (40% of the subjects had a concordance between the perception of their dominant leg and the limb reaching the highest jump height. Using the DL as the discriminating variable, significant (p<0.05 inter-limb differences were found in the total group of players. When comparing between sexes, significant differences (p<0.05 arose in the female group only. With regard to the WL vs. the SL, significant (p<0.05 differences were noted in the whole group and when stratified into males and females. The mean ASI ranged from 9.31% (males to 12.84% (females and from 10.49% (males to 14.26% (females, when comparing the DL vs. the NDL and the SL vs. the WL, respectively. Subjective expression of leg dominance cannot be used as a predictor of limb jump performance. Vertical jump asymmetry of 10-15% exists and this can be considered as a reference value for male and female basketball and volleyball players.

  2. Lower Extremity Kinematics Differed Between a Controlled Drop-Jump and Volleyball-Takeoffs.

    Science.gov (United States)

    Beardt, Bradley S; McCollum, Myranda R; Hinshaw, Taylour J; Layer, Jacob S; Wilson, Margaret A; Zhu, Qin; Dai, Boyi

    2018-04-03

    Previous studies utilizing jump-landing biomechanics to predict anterior cruciate ligament injuries have shown inconsistent findings. The purpose of this study was to quantify the differences and correlations in jump-landing kinematics between a drop-jump, a controlled volleyball-takeoff, and a simulated-game volleyball-takeoff. Seventeen female volleyball players performed these three tasks on a volleyball court while three-dimensional kinematic data were collected by three calibrated camcorders. Participants demonstrated significantly increased jump height, shorter stance time, increased time differences in initial contact between two feet, increased knee and hip flexion at initial contact and decreased peak knee and hip flexion for both left and right legs, and decreased knee-ankle distance ratio at the lowest height of mid-hip for the two volleyball-takeoffs compared with the drop-jump (p jump and two volleyball-takeoffs. Controlled drop-jump kinematics may not represent jump-landing kinematics exhibited during volleyball competition. Jump-landing mechanics during sports-specific tasks may better represent those exhibited during sports competition and their associated risk of ACL injury compared with the drop-jump.

  3. Comparison of posture among adolescent male volleyball players and non-athletes

    Science.gov (United States)

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

  4. Enhancing physical performance in male volleyball players with a caffeine-containing energy drink.

    Science.gov (United States)

    Del Coso, Juan; Pérez-López, Alberto; Abian-Vicen, Javier; Salinero, Juan Jose; Lara, Beatriz; Valadés, David

    2014-11-01

    There are no scientific data about the effects of caffeine intake on volleyball performance. The aim of this study was to investigate the effect of a caffeine-containing energy drink to enhance physical performance in male volleyball players. A double-blind, placebo-controlled, randomized experimental design was used. In 2 different sessions separated by 1 wk, 15 college volleyball players ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo). After 60 min, participants performed volleyball-specific tests: standing spike test, maximal squat jump (SJ), maximal countermovement jump (CMJ), 15-s rebound jump test (15RJ), and agility T-test. Later, a simulated volleyball match was played and recorded. In comparison with the placebo drink, the ingestion of the caffeinated energy drink increased ball velocity in the spike test (73 ± 9 vs 75 ± 10 km/h, P volleyball actions more frequently (24.6% ± 14.3% vs 34.3% ± 16.5%, P volleyball players.

  5. Incidence, aetiology and prevention of musculoskeletal injuries in volleyball: A systematic review of the literature.

    Science.gov (United States)

    Kilic, O; Maas, M; Verhagen, E; Zwerver, J; Gouttebarge, V

    2017-07-01

    Currently, there is no overview of the incidence and (volleyball-specific) risk factors of musculoskeletal injuries among volleyball players, nor any insight into the effect of preventive measures on the incidence of injuries in volleyball. This study aimed to review systematically the scientific evidence on the incidence, prevalence, aetiology and preventive measures of volleyball injuries. To this end, a highly sensitive search strategy was built based on two groups of keywords (and their synonyms). Two electronic databases were searched, namely Medline (biomedical literature) via Pubmed, and SPORTDiscus (sports and sports medicine literature) via EBSCOhost. The results showed that ankle, knee and shoulder injuries are the most common injuries sustained while playing volleyball. Results are presented separately for acute and overuse injuries, as well as for contact and non-contact injuries. Measures to prevent musculoskeletal injuries, anterior knee injuries and ankle injuries were identified in the scientific literature. These preventive measures were found to have a significant effect on decreasing the occurrence of volleyball injuries (for instance on ankle injuries with a reduction from 0.9 to 0.5 injuries per 1000 player hours). Our systematic review showed that musculoskeletal injuries are common among volleyball players, while effective preventive measures remain scarce. Further epidemiological studies should focus on other specific injuries besides knee and ankle injuries, and should also report their prevalence and not only the incidence. Additionally, high-quality studies on the aetiology and prevention of shoulder injuries are lacking and should be a focus of future studies.

  6. Comparison of posture among adolescent male volleyball players and non-athlete

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-10-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  7. Comparison of posture among adolescent male volleyball players and non-athletes

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-11-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  8. High Prevalence of Nontraumatic Shoulder Pain in a Regional Sample of Female High School Volleyball Athletes

    Science.gov (United States)

    Frisch, Kayt E.; Clark, Jacob; Hanson, Chad; Fagerness, Chris; Conway, Adam; Hoogendoorn, Lindsay

    2017-01-01

    Background: Shoulder pain is becoming increasingly problematic in young players as volleyball gains popularity. Associations between repetitive motion and pain and overuse injury have been observed in other overhand sports (most notably baseball). Studies of adult athletes suggest that there is a shoulder pain and overuse problem present in volleyball players, but minimal research has been done to establish rates and causes in juvenile participants. Purpose: To establish rates of shoulder pain, regardless of whether it resulted in a loss of playing time, in female high school volleyball players. A secondary goal was to determine whether high repetition volumes correlated with an increased likelihood of experiencing pain. Study Design: Descriptive epidemiology study. Methods: A self-report survey focusing on the prevalence of pain not associated with a traumatic event in female high school youth volleyball players was developed. Survey questions were formulated by certified athletic trainers, experienced volleyball coaches, and biomechanics experts. Surveys were received from 175 healthy, active high school volleyball players in Iowa, South Dakota, and Minnesota. Results: Forty percent (70/175) of active high school volleyball players remembered experiencing shoulder pain not related to traumatic injury, but only 33% (23/70) reported taking time off to recover from the pain. Based on these self-reported data, activities associated with significantly increased risk of nontraumatic shoulder pain included number of years playing competitive volleyball (P = .01) and lifting weights out of season (P = .001). Players who reported multiple risk factors were more likely to experience nontraumatic shoulder pain. Conclusion: When using time off for recovery as the primary injury criterion, we found that the incidence of shoulder pain is more than twice as high as the incidence of injury reported by previous studies. Findings also indicated that the incidence of shoulder pain

  9. Preventing musculoskeletal injuries among recreational adult volleyball players: design of a randomised prospective controlled trial.

    Science.gov (United States)

    Gouttebarge, Vincent; Zwerver, Johannes; Verhagen, Evert

    2017-08-02

    Both acute and overuse injuries are common among recreational volleyball players, especially finger/wrist, ankle, shoulder and knee injuries. Consequently, an intervention ('VolleyVeilig') was developed to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational volleyball players. This article describes the design of a study evaluating the effectiveness of the developed intervention on the one-season occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational adult volleyball players. A randomized prospective controlled trial with a follow-up period of one volleyball season will be conducted. Participants will be healthy recreational adult volleyball players (18 years of age or older) practicing volleyball (training and/or match) at least twice a week. The intervention ('VolleyVeilig') consists of a warm-up program based on more than 50 distinct exercises (with different variations and levels). The effect of the intervention programme on the occurrence of injuries will be compared to volleyball as usual. Outcome measures will be incidence of acute injury (expressed as number of injuries per 1000 h of play) and prevalence of overuse injuries (expressed as percentage). This study will be one of the first randomized prospective controlled trials evaluating the effectiveness of an intervention on the occurrence of both acute and overuse injuries among recreational adult volleyball players. Outcome of this study could possibly lead to the nationwide implementation of the intervention in all volleyball clubs in The Netherlands, ultimately resulting in less injuries. Dutch Trial Registration NTR6202 , registered February 1st 2017. Version 3, February 2017.

  10. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    Science.gov (United States)

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  11. High Prevalence of Nontraumatic Shoulder Pain in a Regional Sample of Female High School Volleyball Athletes.

    Science.gov (United States)

    Frisch, Kayt E; Clark, Jacob; Hanson, Chad; Fagerness, Chris; Conway, Adam; Hoogendoorn, Lindsay

    2017-06-01

    Shoulder pain is becoming increasingly problematic in young players as volleyball gains popularity. Associations between repetitive motion and pain and overuse injury have been observed in other overhand sports (most notably baseball). Studies of adult athletes suggest that there is a shoulder pain and overuse problem present in volleyball players, but minimal research has been done to establish rates and causes in juvenile participants. To establish rates of shoulder pain, regardless of whether it resulted in a loss of playing time, in female high school volleyball players. A secondary goal was to determine whether high repetition volumes correlated with an increased likelihood of experiencing pain. Descriptive epidemiology study. A self-report survey focusing on the prevalence of pain not associated with a traumatic event in female high school youth volleyball players was developed. Survey questions were formulated by certified athletic trainers, experienced volleyball coaches, and biomechanics experts. Surveys were received from 175 healthy, active high school volleyball players in Iowa, South Dakota, and Minnesota. Forty percent (70/175) of active high school volleyball players remembered experiencing shoulder pain not related to traumatic injury, but only 33% (23/70) reported taking time off to recover from the pain. Based on these self-reported data, activities associated with significantly increased risk of nontraumatic shoulder pain included number of years playing competitive volleyball ( P = .01) and lifting weights out of season ( P = .001). Players who reported multiple risk factors were more likely to experience nontraumatic shoulder pain. When using time off for recovery as the primary injury criterion, we found that the incidence of shoulder pain is more than twice as high as the incidence of injury reported by previous studies. Findings also indicated that the incidence of shoulder pain may be correlated with volume of previous volleyball experience.

  12. Structural and electronic stability of a volleyball-shaped B80 fullerene

    Science.gov (United States)

    Wang, Xiao-Qian

    2010-10-01

    We have studied the structural and electronic characteristics of a volleyball-shaped B80 cage using first-principles density-functional calculations. In contrast to the popularly ratified “magic” B80 buckyball with 20 hexagonal pyramids and 12 hollow pentagons, the volleyball-shaped B80 constitutes 12 pentagonal pyramids, 8 hexagonal pyramids, and 12 hollow hexagons. The B80 volleyball is markedly more stable than the previously assumed magic B80 buckyball, which is attributed to the improved aromaticity associated with the distinct configuration.

  13. Strength of the Shoulder Rotators in Second-League Volleyball Players

    Directory of Open Access Journals (Sweden)

    Popieluch Aneta

    2015-12-01

    Full Text Available Introduction. The main aim of the study was to assess the strength of the shoulder rotator muscles of a group of second-league volleyball players. These muscles are assumed to have a crucial impact on attack effectiveness in volleyball. Strength was assessed based on peak torque values obtained for the rotator muscles measured using the maximal voluntary contraction (MVC method. Torque was measured in both limbs and the differences between the two limbs were examined. The torque values obtained for the volleyball players were also compared against those measured in a group of students who had never trained any sports.

  14. Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players.

    Science.gov (United States)

    Van De Pol, Daan; Alaeikhanehshir, Sena; Maas, Mario; Kuijer, P Paul F M

    2016-01-01

    The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30-15.07) and sex (female) (OR 4.62, 90% CI 1.15-18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.

  15. Systematic review on sports performance in beach volleyball from match analysis

    Directory of Open Access Journals (Sweden)

    Alexandre Igor Araripe Medeiros

    2014-10-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2014v16n6p698   The present article aimed to perform a systematic review of the available literature in relation to the analysis of sports performance in beach volleyball from match analysis. Web of Science, SportDiscus®, PubMed, Scopus and Academic Search Complete databases were used to identify peer-reviewed published articles. The authors conducted a content analysis according to goals, variables of analysis and methods used in studies. In general, three research lines were determined: analysis of the functional dependence of the game actions and their relation with success, performance according to gender, and the effect of changing the rules on the game performance. In relation to methodology, an evolution from descriptive studies to studies of comparative nature can be seen and, more recently, there has been a focus on predictive nature. This new trend breaks with the research based on simple cause and effect relations, and focuses on the analysis of the game events, namely related to tactical-technical performance indicators, in a non-linear and interactive way, considering the game as a complex and dynamic system. The limitations of the studies analyzed show the need for further studies to investigate the identification of game patterns for the different game levels; integration of situational variables in the study of the performance of teams (such as match status and the quality of opposition.

  16. Eastern Scheldt Sand, Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

    The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...... will described. In this connection, the procedure for preparation of the soil specimens will be presented, and the actual performance of the tests will be briefly outlined. Finally, the procedure for processing of the measurements from the laboratory in order to obtain usable data will be described. The final...

  17. Overload and neovascularization of shoulder tendons in volleyball players

    Science.gov (United States)

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  18. ANTHROPOMETRIC AND MOTOR CHARACTERISTICS IN VOLLEYBALL AND BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Enver Tahiraj

    2011-09-01

    Full Text Available The purpose of this study is the morphological and motor status players for both teams, and then based on the results of anthropometric and motor status of this work can also do a comparative analysis between these two sports, volleyball and basketball. Therefore, the present study is in the results (achieved of the differences and their special achievement and to skills top players. In this research, we have participation 30 players (15 for each team volleyball and basketball, the teams is from Pristina. It should be noted that all players are fully able to follow regular exercise in their clubs. Those two clubs in Pristina, have the training five days a week, the clubs are in super league and the current champion in country. We as a coach interesed about the comparisons and differences of these two sports for anthropometric and motor characteristics, and in these sports, in those two sports players have a special that is characterized by height body and explosive power. We think, that this research work serves as a continuation of the way and further research on these two sports that have a significant increase from the psycho-physical and anthropometric aspects

  19. MEANING TO BE VOLLEYBALL PLAYER IN CAREER TRANSITION PHASE

    Directory of Open Access Journals (Sweden)

    Adriana Justino

    2016-09-01

    Full Text Available The objective of this study is to assess the meaning of being that a volleyball player for the under-19 players who are experiencing a transition in their in career. Sixteen male players aged 17 and 18 were evaluated, by being asked the triggering question “What does being a volleyball player mean to you?” The analysis of the discourses was carried out according to the procedures recommended by Miles & Huberman (2004. Four response categories resulted: psychoemotional and behavioral skills, emotions in sport, recognition and financial return, skills as an athlete/player. The athletes showed that the meaning of sport lies especially in the passion for practice, but also, in the improving of their tactics and techniques, in the development of psychoemotional and behavioral skills, in the professional recognition and, to a lesser degree, in the financial aspect. Most athletes state they intend to continue in the juvenile sports categories, therefore, understanding the meaning of this activity in their life can be the key to the elaboration of a plan of psychological preparation whose aim is to provide support to their needs in this moment of professional choice.

  20. Physical actions and work-rest time in men's beach volleyball

    Directory of Open Access Journals (Sweden)

    José Manuel Palao

    2014-09-01

    Full Text Available The purpose of this study was to assess the ball contacts, jumps, hits, work time, and rest ratio in male beach volleyball players in relation to their tactical roles. The sample of this study included 6970 rallies played by 91 beach volleyball players, which corresponded to 179 sets of the 2008 Men's Beach Volleyball World Tour (FIVB. We analyzed: ball contacts, jumps, hits, work time, rest time, set (first, second or third, and player's tactical role (e.g., defense specialist, blocker, or no specialization. A significantly higher number of jumps were executed by blockers. No differences were found in the third set for any of the physical variables studied. This paper provides references about the physical demands (e.g., contacts, jumps, and hits for blockers and defense specialists and temporal patterns of the beach volleyball game (i.e., work and rest time for two-set matches and three-set matches.

  1. Neuromechanical evidence of improved neuromuscular control around knee joint in volleyball players.

    Science.gov (United States)

    Masci, Ilaria; Vannozzi, Giuseppe; Gizzi, Leonardo; Bellotti, Pasquale; Felici, Francesco

    2010-02-01

    The aim of the present work was to verify that skilled volleyball players present specific adaptations in both neuromuscular control and movement biomechanics, showing an improved neuromuscular control around the knee joint than in non-jumper athletes. Seven male volleyball players and seven male non-jumper athletes were recruited for this study. The following tests were performed in a random order: single countermovement jump (CMJ), single squat jump. At the end of the series, subjects performed a repetitive CMJ test. Electromyographic signals were recorded from vastus lateralis and biceps femoris muscles on both sides. Ground reaction forces and moments were measured with a force plate. Volleyball athletes performed better in all tests and were more resistant to fatigue than non-jumper athletes. Furthermore, volleyball athletes showed a reduced co-activation of knee flexor/extensor muscles. The present results seem to stand for a neural adaptation of the motor control scheme to training.

  2. Sex differences in discriminative power of volleyball game-related statistics.

    Science.gov (United States)

    João, Paulo Vicente; Leite, Nuno; Mesquita, Isabel; Sampaio, Jaime

    2010-12-01

    To identify sex differences in volleyball game-related statistics, the game-related statistics of several World Championships in 2007 (N=132) were analyzed using the software VIS from the International Volleyball Federation. Discriminant analysis was used to identify the game-related statistics which better discriminated performances by sex. Analysis yielded an emphasis on fault serves (SC = -.40), shot spikes (SC = .40), and reception digs (SC = .31). Specific robust numbers represent that considerable variability was evident in the game-related statistics profile, as men's volleyball games were better associated with terminal actions (errors of service), and women's volleyball games were characterized by continuous actions (in defense and attack). These differences may be related to the anthropometric and physiological differences between women and men and their influence on performance profiles.

  3. STRUCTURE OF ISOLATED PRECISION FACTORS OF THE MALE STUDENT ON VOLLEYBALL

    OpenAIRE

    Bahri Gjinovci; Malsor Gjonbalaj; Besnik Morina; Florian Miftari

    2015-01-01

    The aim of this study was to verify the current status of accuracy in volleyball for the students of the faculty of physical education and sports of the University of Prishtina, all the students have successfully passed the exam in volleyball. Also, another aim was to observe whether there are significant statistical differences between both generations of students. In the study were included 70 students (35 from the second academic year and 35 from the fourth academic year). To achieve the a...

  4. The patellar tendon in junior elite volleyball players and an Olympic elite weightlifter

    OpenAIRE

    Gisslén, Karl

    2006-01-01

    The principal aim of the present thesis was to prospectively follow (clinical status and ultrasound + Doppler findings) the patellar tendons in the young elite volleyball players at the Swedish National Centre for high school volleyball in Falköping. In an Olympic weightlifter with chronic painful jumper´s knee, the effects of treatment with sclerosing injections followed by early instituted very heavy weightlifting training, was also evaluated. First, in a prevalence study, we demonstrated t...

  5. Rotational Angles and Velocities During Down the Line and Diagonal Across Court Volleyball Spikes

    OpenAIRE

    Justin R. Brown; Bader J. Alsarraf; Mike Waller; Patricia Eisenman; Charlie A. Hicks-Little

    2014-01-01

    The volleyball spike is an explosive movement that is frequently used to end a rally and earn a point. High velocity spikes are an important skill for a successful volleyball offense. Although the influence of vertical jump height and arm velocity on spiked ball velocity (SBV) have been investigated, little is known about the relationship of shoulder and hip angular kinematics with SBV. Other sport skills, like the baseball pitch share similar movement patterns and suggest trunk rotation is i...

  6. High Prevalence of Nontraumatic Shoulder Pain in a Regional Sample of Female High School Volleyball Athletes

    OpenAIRE

    Frisch, Kayt E.; Clark, Jacob; Hanson, Chad; Fagerness, Chris; Conway, Adam; Hoogendoorn, Lindsay

    2017-01-01

    Background: Shoulder pain is becoming increasingly problematic in young players as volleyball gains popularity. Associations between repetitive motion and pain and overuse injury have been observed in other overhand sports (most notably baseball). Studies of adult athletes suggest that there is a shoulder pain and overuse problem present in volleyball players, but minimal research has been done to establish rates and causes in juvenile participants. Purpose: To establish rates of shoulder pai...

  7. Anthropometric characteristics and motor abilities in 13-15 year old female volleyball players

    OpenAIRE

    Nešić, Goran; Majstorović, Nikola; Sikimić, Milan; Marković, Srđan; Ilić, Dejan; Grbić, Vladimir; Osmankač, Nedžad; Savić, Zoran

    2014-01-01

    The goal of this research was to determine whether there is a difference in the manifestation of measured anthropometric characteristics and tested motor abilities of female volleyball players that are 13-15 years old. The sample of participants consists of 62 female volleyball players divided into three groups according to their age. The sample of variables has two sub-samples: 18 variables belonging to anthropometric space and 14 variables belonging to the space of motor skills. A variance ...

  8. The effect of ankle bracing on knee kinetics and kinematics during volleyball-specific tasks.

    Science.gov (United States)

    West, T; Ng, L; Campbell, A

    2014-12-01

    The purpose of this study was to examine the effects of ankle bracing on knee kinetics and kinematics during volleyball tasks. Fifteen healthy, elite, female volleyball players performed a series of straight-line and lateral volleyball tasks with no brace and when wearing an ankle brace. A 14-camera Vicon motion analysis system and AMTI force plate were used to capture the kinetic and kinematic data. Knee range of motion, peak knee anterior-posterior and medial-lateral shear forces, and peak ground reaction forces that occurred between initial contact with the force plate and toe off were compared using paired sample t-tests between the braced and non-braced conditions (P volleyball tasks. However, ankle bracing was demonstrated to reduce knee lateral shear forces during all of the lateral movement volleyball tasks. Wearing the Active Ankle T2 brace will not impact knee joint range of motion and may in fact reduce shear loading to the knee joint in volleyball players. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Risk factors for patellar tendinopathy in basketball and volleyball players: a cross-sectional study.

    Science.gov (United States)

    van der Worp, H; van Ark, M; Zwerver, J; van den Akker-Scheek, I

    2012-12-01

    Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. The findings are conflicting, though, and most research has been conducted on elite athletes. The aim of the current study is to determine the risk factors for PT in a large representative sample of basketball and volleyball players. Separate risk factors for men and women, basketball and volleyball players, and athletes with unilateral and bilateral PT were identified. All basketball and volleyball players between ages 18 and 35 from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete an online questionnaire on knee complaints and risk factors for PT. The logistic regression analyses included 2224 subjects. The risk factors for PT were age, playing at the national level, being male and playing volleyball (compared with playing basketball). The risk factors for men and women were comparable. Among volleyball players, outside hitters and middle blockers/hitters had an increased risk compared with setters. For basketball players, no risk factors could be identified. No differences in the risk factors were found between athletes with unilateral and bilateral PT. These findings should be taken into account for prevention and rehabilitation purposes. © 2011 John Wiley & Sons A/S.

  10. Level of Transformation of Motor Skills in Female Volleyball Players Influenced by Training Operators

    Directory of Open Access Journals (Sweden)

    Ifet Mahmutović

    2016-06-01

    Full Text Available The aim of this paper is to determine the level of improvement of motor skills of female volleyball players influenced by kinesiology operators in a period of 6 months. Research was conducted on sample subject of 130 female volleyball players aged from 13±0.6 (mean±SD. Sample variables are divided in two groups: 9 variables of assessment of basic motor skills and 5 variables of assessment of situational motor skills. Analysing difference of arithmetic means between of initial and final measures of treated variables it is determined that there is statistically significant difference on the level Sig=0.001, except for variables of Jelka test which determinates speed duration of female volleyball players. Analysis of quantity changes of basic motor skills, shows that the most important projections on selected discriminative function of basic motor skills have the following variables: body lifting in 30 sec; dynamometry of a hand, hand tapping; pull-up; throwing a 1 kg ball from lying position; side defence movement; push-up on bars and situational motor skill are the variables: precision of tactic serving; consecutive bumping; wall-spikes. Comprehensive development of female volleyball players and diversity in the level of volleyball specialization of the development will depend on systematic work on treated motor skills. This program appeared to be efficient. However, it is necessary to gradually increase the demands for the female volleyball players and to put the accent on performance of acquired situational motor skills in future work.

  11. Pedagogical characteristics of the systems for assessing the technical and tactical skills of qualified volleyball players

    Directory of Open Access Journals (Sweden)

    Мykhailo Oliinyk

    2017-12-01

    Full Text Available Purpose: on the basis of the analysis of the special literature and their own experimental studies, to determine the characteristics of the systems for assessing the technical and tactical skills of qualified volleyball players. Material & Methods: study was conducted on the basis of the material of the national team of Zaporozhye State Medical University on volleyball. Analysis and generalization of the data of scientific and methodical literature are used; registration, analysis and interpretation of indicators of technical and tactical actions of qualified volleyball players in training and competitive processes; pedagogical observations; algorithms for calculating the quantitative and qualitative indicators of technical and tactical skill in volleyball; methods of mathematical statistics. Results: data on the existence of a strong statistical relationship between the systems of assessment of technical and tactical skills of qualified volleyball players, taking into account the specificity of the game role. Conclusion: shows the specifics of the application of various systems for assessing the technical and tactical skills of qualified volleyball players, taking into account the factors of the game role, noted the methodological features of special analysis and interpretation of indicators of technical and tactical actions in the adversarial process.

  12. Influence green sand system by core sand additions

    Directory of Open Access Journals (Sweden)

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  13. Lateral Scapular Slide Test and Scapular Mobility in Volleyball Players

    Science.gov (United States)

    Ozunlu, Nihan; Tekeli, Hatice; Baltaci, Gul

    2011-01-01

    Context: The stability of the scapula in relation to the entire moving upper extremity is the key in the throwing sequence. The importance of scapular positioning in volleyball players has been well documented in the literature, but no one has compared scapular positioning between volleyball players and sedentary people. Objective: To compare measurements of scapular mobility obtained using the lateral scapular slide test between volleyball players and sedentary participants without shoulder impairments and to compare changes in scapular mobility in players according to the number of years of sport participation. Design: Cross-sectional study. Setting: University research laboratory. Patients or Other Participants: A total of 121 people at a single university volunteered. Of these, 67 were sedentary (age = 24.3 ± 2.34 years, height = 1.69 ± 0.09 m, mass = 65.1 ± 11.91 kg); 54 were volleyball players from 4 professional teams and were separated into 2 groups according to their years of sport participation. The first group was named young players (n = 31; age = 17.7 ± 2.58 years, height = 1.83 ± 0.10 m, mass = 68.3 ± 12.21 kg, sport participation ≤ 9 years), and the second group was named old players (n = 23; age = 26.9 ± 3.39 years, height = 1.95 ± 4.38 m, mass = 90.7 ± 5.75 kg, sport participation ≥ 10 years). Main Outcome Measure(s): Study participants completed a rating scale for pain and a questionnaire about demographic and shoulder problems. One assessor performed the lateral scapular slide test and additional flexibility measurements around the shoulder girdle. Flexibility (external rotation, internal rotation) and scapular position (1, 2, 3) were compared among groups (young players, old players, sedentary people) and between sides (dominant, nondominant). Results: In sedentary participants, we found differences for position 1 (t66 = 3.327, P = .002), position 2 (t66 = 2.491, P = .004), position 3 (t66 = 2.512, P = .006), and internal rotation

  14. Are Tendinopathies really a common injury in volleyball?

    Science.gov (United States)

    Bustos, Aldo; Locaso, Fernando

    2017-01-01

    Objectives: To perform a description of tendinopathies as an injury in volleyball high performance. Methods: An observational and prospective study was conducted from 2014-2016 in the senior Argentinian volleyball team. The same was held by two observers. Moreover, 78 athletes were evaluated. We support Dvorak’s claims that an injury is determined by the loss of at least one training session or a match. Results: 78 players were exposed to 21812 hours of training and matches. As a result 37 injuries were evaluated in 31 players. Taking into account tendinopathies, it can be said that 34 players consulted 412 times, showing a prevalence of 43.5% of the whole enquires but when we refer to the same pathology as injury the average lowers, presenting 8 lesions in 6 players and showing a prevalence of 7.6% as injuries. Incidence of tendon injuries is 0.32 per 1000 hours of exposure Tendon Injuries: 5 were patellar, 2 supraspinatus, 1 aquiles. 5 Slight, 2 moderate, 1 severe. Conclusion: Clearly, tendinopathy is a common problem in this sport but it is not a common cause of injury. This is demonstrated in prevalence rates whereas 43.5 % just consulted and 7,6 % suffer from real injuries. We think this might be due to several factors such as, advances in medical therapy, preventive protocols and increase in thresholds of pain that high-performance athletes can bear. In our experience this pathology was shown to be the third leading cause of injuries. In 2016 we did not deal with any case of injury for tendinopathy.

  15. Singing Sand Dunes

    Indian Academy of Sciences (India)

    ble low-frequency (s. 75–105 Hz), that can some- times be heard up to 10 km away. Scientific in- vestigations suggest that the sustained low fre- quency sound of sand dunes that resembles a pure note from a musical instrument, is due to the synchronized motion of well-sorted dry sand grains when they spontaneously ...

  16. Catch-Up: A Rule That Makes Service Sports More Competitive

    OpenAIRE

    Brams, Steven J.; Ismail, Mehmet S.; Kilgour, D. Marc; Stromquist, Walter

    2016-01-01

    Service sports include two-player contests such as volleyball, badminton, and squash. We analyze four rules, including the Standard Rule (SR), in which a player continues to serve until he or she loses. The Catch-Up Rule (CR) gives the serve to the player who has lost the previous point—as opposed to the player who won the previous point, as under SR. We also consider two Trailing Rules that make the server the player who trails in total score. Surprisingly, compared with SR, only CR gives th...

  17. Catch-Up:A Rule that Makes Service Sports More Competitive

    OpenAIRE

    Brams, Steven; Ismail, Mehmet; Kilgour, Marc; Stromquist, Walter

    2018-01-01

    Service sports include two-player contests such as volleyball, badminton, and squash. We analyze four rules, including the Standard Rule (SR), in which a player continues to serve until he or she loses. The Catch-Up Rule (CR) gives the serve to the player who has lost the previous point—as opposed to the player who won the previous point, as under SR. We also consider two Trailing Rules that make the server the player who trails in total score. Surprisingly, compared with SR, only CR gives th...

  18. Evaluation of the Effect of Core Training on the Leap Power and Motor Characteristics of the 14-16 Years Old Female Volleyball Players

    Science.gov (United States)

    Bilici, Ömer Faruk; Selçuk, Muzaffer

    2018-01-01

    In this study, it was aimed to assess the effects of core training on the vertical jump strength and some motor characteristics of 14-16 aged female volleyball players. Thirty-four female athletes playing volleyball in Van province participated in the study voluntarily. The average age of volleyball players is 15.47, the weight average is 53.66 kg…

  19. New generation expandable sand screens

    OpenAIRE

    Syltøy, Christer

    2014-01-01

    Master's thesis in Petroleum engineering This thesis aims to give a general insight into sand control and various sorts of sand control measures and applications of sand control tools. Special focus will be given to expandable sand screens – a technology which came about in the late 1990’s through the use of flexible, expandable tubulars as base pipe in sand screens. More specifically Darcy’s Hydraulic Endurance Screens, a compliant sand screen system using hydraulic activation, and the fu...

  20. Physiologic performance test differences in female volleyball athletes by competition level and player position.

    Science.gov (United States)

    Schaal, Monique; Ransdell, Lynda B; Simonson, Shawn R; Gao, Yong

    2013-07-01

    The purpose of this study was to examine physiologic performance test differences by competition level (high school and Division-I collegiate athletes) and player position (hitter, setter, defensive specialist) in 4 volleyball-related tests. A secondary purpose was to establish whether a 150-yd shuttle could be used as a field test to assess anaerobic capacity. Female participants from 4 varsity high school volleyball teams (n = 27) and 2 Division-I collegiate volleyball teams (n = 26) were recruited for the study. Participants completed 4 performance-based field tests (vertical jump, agility T-test, and 150- and 300-yd shuttle runs) after completing a standardized dynamic warm-up. A 2-way multivariate analysis of variance with Bonferroni post hoc adjustments (when appropriate) and effect sizes were used for the analyses. The most important findings of this study were that (a) college volleyball athletes were older, heavier, and taller than high school athletes; (b) high school athletes had performance deficiencies in vertical jump/lower-body power, agility, and anaerobic fitness; (c) lower-body power was the only statistically significant difference in the performance test measures by player position; and (d) the correlation between the 150- and 300-yd shuttle was moderate (r = 0.488). Female high school volleyball players may enhance their ability to play collegiate volleyball by improving their vertical jump, lower-body power, agility, and anaerobic fitness. Furthermore, all player positions should emphasize lower-body power conditioning. These physical test scores provide baseline performance scores that should help strength and conditioning coaches create programs that will address deficits in female volleyball player performance, especially as they transition from high school to college.

  1. Relations of competitive state anxiety and efficacy of young volleyball players.

    Science.gov (United States)

    Milavić, Boris; Jurko, Damir; Grgantov, Zoran

    2013-05-01

    With the aim of validating the Competitive State Anxiety Inventory on a population of young Croatian volleyball players, 286 examinees, 106 male and 180 female volleyball players (average age of 16.09+/-1.83), filled out the CSAI-2, constructed by Martens, Vealey, Burton, Bump and Smith (1990)1. Given the fact that all scales of the Competitive State Anxiety Inventory have good homogeneity, reliability and sensitivity, it can be concluded that they represent high-quality measuring instruments for measuring psychological characteristics of young volleyball players. Young male and female volleyball players generally have a moderate level of self-confidence, and their cognitive anxiety is more prominent that somatic anxiety. In order to determine the age and gender differences in somatic and cognitive anxiety and self-confidence, parametric analysis of differences was performed and coefficients of the independent samples t-test were calculated. By analysis of differences according to age, it has been established that female junior players, in relation to female youth players, express a significantly lower level of somatic and cognitive anxiety and a significantly higher level of self-confidence. As opposed to female players, male youth and junior players do not differ in any of the analysed variables. By analysis of differences according to gender, it has been established that male youth players have a significantly higher level of self-confidence in comparison to female youth players. No significant differences were found in the level of competitive anxiety and self-confidence by analysis of variance between different player roles. No significant differences were found by discriminant analysis in somatic and cognitive anxiety, and self-confidence of female volleyball players of different situational efficacy. The group of least efficient male volleyball players is characterized by a very low level of self-confidence, while the most efficient group of volleyball

  2. Are the take-off and landing phase dynamics of the volleyball spike jump related to patellar tendinopathy?

    NARCIS (Netherlands)

    Bisseling, R.W.; Hof, A.L.; Bredeweg, S.W.; Zwerver, J.; Mulder, T.

    Objective: The causal mechanism of the chronic sports injury patellar tendinopathy is not well understood. The aim of the present study was to compare ankle and knee joint dynamics during the performance of the volleyball spike jump between healthy volleyball players (n = 8) and asymptomatic

  3. Pre-Activity and Post-Activity Stretching Perceptions and Practices in NCAA Division I Volleyball Programs

    Science.gov (United States)

    Judge, Lawrence W.; Bodey, Kimberly J.; Bellar, David; Bottone, Adam; Wanless, Elizabeth

    2010-01-01

    The purpose of this study was to determine if NCAA Division I women's volleyball programs were in compliance with suggested current pre- and post-activity stretching protocols. Questionnaires were sent to NCAA division I women's volleyball programs in the United States. Fifty six coaches (23 males & 33 females) participated in the study. Some…

  4. Risk factors associated with self-reported symptoms of digital ischemia in elite male volleyball players in the Netherlands

    NARCIS (Netherlands)

    van de pol, D.; Kuijer, P. P. F. M.; Langenhorst, T.; Maas, M.

    2014-01-01

    One in every four elite male volleyball players in the Netherlands reported blue or pale digits in the dominant hand. Little is known about risk factors. To assess whether personal-, sports-, and work-related risk factors are associated with these symptoms in these volleyball players, a survey was

  5. Examination of the Relationship between Coach-Athlete Communication Levels and Perceived Motivational Climate for Volleyball Players

    Science.gov (United States)

    Avci, Kübra Seden; Çepikkurt, Fatma; Kale, Esen Kizildag

    2018-01-01

    The aim of this study was to reveal the relationship between the athlete-coach relationship and the motivational climate created by the coach. In this study, relational survey model was used. The study sample included 96 female volleyball players who are active players at Turkey Women Volleyball 3rd League. "The Coach-Athlete Relationship…

  6. Como pensar o voleibol de praia sociologicamente How to think beach volleyball sociologicaly

    Directory of Open Access Journals (Sweden)

    Gilmar Francisco Afonso

    2012-03-01

    Full Text Available Este artigo trata de uma análise sociológica da história do Voleibol de Praia. Aqui procuramos responder: por que o desenvolvimento internacional da modalidade ocorreu no Brasil e não nos EUA? Como hipótese apresentamos que a estrutura do campo Voleibol de Praia vem sendo determinada pela disputa de duas instituições, a Federação Internacional de Voleibol (FIVB e a Association of Volleyball Professionals (AVP. Os objetivos foram investigar por que o Brasil foi o local onde o Voleibol de Praia se transformou em show business internacional e analisar as configurações entre os agentes/estruturas que compõem o campo. O recorte compreendeu o intervalo de 1985 a 2004. Como referencial teórico metodológico de análise, buscamos na teoria dos campos de Pierre Bourdieu o instrumental capaz de explicitar as relações que se estabelecem no contexto socioeconômico contemporâneo, aplicando-o na leitura do desenvolvimento do Voleibol de Praia. Constatamos que a FIVB assumiu o controle do campo e o Brasil passou a ser uma estrutura estruturante da modalidade.This study carried out a sociological analysis of the history of Beach Volleyball. The problem was: why has the development of Beach Volleyball as an international sport occurred in Brazil rather than in the USA? The hypothesis proposed that the framework of the field of Beach Volleyball has been defined by the dispute between two institutions, the Fèdèration Internationale de Volleyball (FIVB and the Association of Volleyball Professionals (AVP. The outlined goals were to investigate why Brazil came to be where Beach Volleyball was transformed into International Show Business and analyze the structure of the interdependent relationships among the sub components that make up the field. The proposed period included the years 1985 to 2004. The instrument capable of expounding the relationships that are established in the contemporary socioeconomic context was found in the 'theory of fields

  7. Vertical Jumping Tests versus Wingate Anaerobic Test in Female Volleyball Players: The Role of Age

    Science.gov (United States)

    Nikolaidis, Pantelis Theodoros; Afonso, Jose; Clemente-Suarez, Vicente Javier; Alvarado, Jose Rafael Padilla; Driss, Tarak; Knechtle, Beat; Torres-Luque, Gema

    2016-01-01

    Single and continuous vertical jumping tests, as well as the Wingate anaerobic test (WAnT), are commonly used to assess the short-term muscle power of female volleyball players; however, the relationship among these tests has not been studied adequately. Thus, the aim of the present study was to examine the relationship of single and continuous vertical jumps with the WAnT in female volleyball players. Seventy adolescent (age 16.0 ± 1.0 years, body mass 62.5 ± 7.1 kg, height 170.4 ± 6.1 cm, body fat 24.2% ± 4.3%) and 108 adult female volleyball players (age 24.8 ± 5.2 years, body mass 66.5 ± 8.7 kg, height 173.2 ± 7.4 cm, body fat 22.0% ± 5.1%) performed the squat jump (SJ), countermovement jump (CMJ), Abalakov jump (AJ), 30 s Bosco test and WAnT (peak power, Ppeak; mean power, Pmean). Mean power in the Bosco test was correlated (low to large magnitude) with Pmean of the WAnT (r = 0.27, p = 0.030 in adolescents versus r = 0.56, p volleyball players. These findings should be taken into account by volleyball coaches and fitness trainers during the assessment of short-term muscle power of their athletes.

  8. Dynamic trunk stabilization: a conceptual back injury prevention program for volleyball athletes.

    Science.gov (United States)

    Smith, Chad E; Nyland, John; Caudill, Paul; Brosky, Joseph; Caborn, David N M

    2008-11-01

    The sport of volleyball creates considerable dynamic trunk stability demands. Back injury occurs all too frequently in volleyball, particularly among female athletes. The purpose of this clinical commentary is to review functional anatomy, muscle coactivation strategies, assessment of trunk muscle performance, and the characteristics of effective exercises for the trunk or core. From this information, a conceptual progressive 3-phase volleyball-specific training program is presented to improve dynamic trunk stability and to potentially reduce the incidence of back injury among volleyball athletes. Phase 1 addresses low-velocity motor control, kinesthetic awareness, and endurance, with the clinician providing cues to teach achievement of biomechanically neutral spine alignment. Phase 2 focuses on progressively higher velocity dynamic multiplanar endurance, coordination, and strength-power challenges integrating upper and lower extremity movements, while maintaining neutral spine alignment. Phase 3 integrates volleyball-specific skill simulations by breaking down composite movement patterns into their component parts, with differing dynamic trunk stability requirements, while maintaining neutral spine alignment. Prospective research is needed to validate the efficacy of this program.

  9. Association of anthropometric qualities with vertical jump performance in elite male volleyball players.

    Science.gov (United States)

    Aouadi, R; Jlid, M C; Khalifa, R; Hermassi, S; Chelly, M S; Van Den Tillaar, R; Gabbett, T

    2012-02-01

    The objective of this study was to examine the association between physical and anthropometric profiles and vertical jump performance in elite volleyball players. Thirty-three elite male volleyball players (21±1 y, 76.9±5.2 kg, 186.5±5 cm) were studied. Several anthropometric measurements (body mass, stature, body mass index, lower limb length and sitting height) together with jumping height anaerobic power of counter movement jump with arm swing (CMJarm) were obtained from all subjects. Forward stepwise multiple linear regression analysis was performed to determine if any of the anthropometric parameters were predictive of CMJarm. Anaerobic power was significantly higher (P≤0.05) in the tallest players relative to their shorter counterparts. A significant relationship was observed between CMJarm and lower limb length (r2=0.69; P0.05) predictors of CMJarm performance. This study demonstrates that lower limb length is correlated with CMJarm in elite male volleyball players. The players with longer lower limbs have the better vertical jump performances and their anaerobic power is higher. These results could be of importance for trained athletes in sports relying on jumping performance, such as basketball, handball or volleyball. Thus, the measurement of anthropometric characteristics, such as stature and lower limb length may assist coaches in the early phases of talent identification in volleyball.

  10. Measurement of talent in volleyball: 15-month follow-up of elite adolescent players.

    Science.gov (United States)

    Lidor, R; Hershko, Y; Bilkevitz, A; Arnon, M; Falk, B

    2007-06-01

    The purpose of this study was two-fold: first, to examine the contribution of a battery of physical and motor tests to early phases of talent detection and early development in volleyball, and second, to differentiate between and compare the motor ability of 16-year-old starter (S) and non-starter (NS) volleyball players. Fifteen male adolescent volleyball players underwent assessment of physical and motor ability 6 times during a 15-month training program; however, not all of them took part in each testing phase. The battery was composed of 8 physical and motor tests and 2 skill tests. The physical and motor tests included 2 speed tests, an agility run, 4 explosive power tests, and an endurance test. The skill tests evaluated service accuracy at rest and following effort. All participants improved their results in all but 2 tests (endurance and skill tests) across testing phases. Comparisons between the S (n=8) and NS (n=7) revealed that only one physical explosive power test (vertical jump with approach), was found to be a good indicator for distinguishing between the 2 groups of players. It was concluded that the volleyball battery of tests was not sensitive enough to distinguish between the ''good'' and ''very good'' players suggesting that physical and motor tests do not reflect open skill ability in volleyball.

  11. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  12. Sand and Gravel Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  13. Influence of the level of speed-strength preparedness on the agility of volleyball players 12–13 years old

    Directory of Open Access Journals (Sweden)

    Oleg Shevchenko

    2018-02-01

    Full Text Available Purpose: determine the impact level of indicators of speed-strength preparedness for the agility of young volleyball players 12–13 years. Material & Methods: analysis of scientific and methodological literature, pedagogical testing of speed-strength qualities and agility, pedagogical experiment, methods of mathematical statistics. The study involved 25 volleyball players aged 12–13 years, training in the basic training group of the second year of training of the sports club "Lokomotiv" in Kharkov. Young athletes were divided into an experimental – 13 people and a control –12 volleyball team. Results: after the introduction of the experimental methodology, a link was found between the level of speed-strength abilities and the agility of volleyball players. Conclusion: the positive influence of development of speed-strength qualities on indicators of agility of volleyball players that is necessary for selection of means and methods in training process of young athletes is proved.

  14. Performance indicators analysis at Brazilian and Italian women's volleyball leagues according to game location, game outcome, and set number.

    Science.gov (United States)

    Campos, Fabio A D; Stanganélli, Luiz C R; Campos, Leandra C B; Pasquarelli, Bruno N; Gómez, Miguel-Angel

    2014-04-01

    This study was done to investigate the advantage of playing at home in elite women's volleyball leagues and the influence of performance indicators in the game score according to set number. The sample consisted of 240 games of the Brazilian Volleyball League (n = 132 games) and the Italian Volleyball League (n = 108 games) from the 2011-2012 season. The relationship of performance indicators (including serve, attack, block, and opponents' errors) with the game outcome (win or lose) was assessed. The results showed that there was a home advantage effect in women's volleyball leagues, with a higher prevalence of victory for the home teams in Brazilian and Italian leagues (58 and 56%, respectively). When related to the performance indicators and among the aspects that were most highly correlated with victory, the attack was the technical indicator that explained most of the results of volleyball games.

  15. Influence of dorsiflexion shoes on neuromuscular fatigue of the plantar flexors after combined tapping-jumping exercises in volleyball players.

    Science.gov (United States)

    Lapole, Thomas; Ahmaidi, Said; Gaillien, Benjamin; Leprêtre, Pierre-Marie

    2013-07-01

    Dorsiflexion shoes could be useful to increase jumping performance. The aim of the present study was to investigate the impact of wearing shoes inducing moderate dorsiflexion (2°) on neuromuscular fatigue induced by volleyball exercises involving multiple stretch-shortening cycles. Squat jump (SJ) and countermovement jump (CMJ) performance, and plantar flexors isometric voluntary and evoked contractile properties were assessed in 10 unfamiliarized trained volleyball players before and after a 10-minute intensive combined tapping-jumping volleyball exercise performed, in blinded randomized conditions, with neutral (0°) or moderate dorsiflexion (2°). No significant difference was observed on SJ performance in neutral and moderate dorsiflexion conditions. However, CMJ height was initially lower with 2° dorsiflexion compared with 0° (p volleyball exercise also induced a significant decrease in maximal voluntary contraction (p volleyball players.

  16. Retorting of bituminous sands

    Energy Technology Data Exchange (ETDEWEB)

    Chaney, P E; Ince, R W; Mason, C M

    1872-09-26

    This method of recovering oil from mined tar sands involves forming compacted tar sands pieces by special conditioning treatment that provides low internal permeability. The compacted pieces are then retorted in fixed bed form. The conditioning treatment can involve rolling of preformed pellets, compaction in a mold or pressure extrusion. Substantial collapsing of the bed during retorting is avoided. (9 claims) (Abstract only - original article not available from T.U.)

  17. 78 FR 76060 - Pacific Ocean off the Pacific Missile Range Facility at Barking Sands, Island of Kauai, Hawaii...

    Science.gov (United States)

    2013-12-16

    ... the Pacific Missile Range Facility at Barking Sands, Island of Kauai, Hawaii; Danger Zone. AGENCY: U.S... Barking Sands, Island of Kauai, Hawaii. The U.S. Navy conducts weapon systems testing and other military... Sands, Island of Kauai, Hawaii. The proposed rule was published in the July 1, 2013 issue of the Federal...

  18. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  19. Cognitive and somatic anxiety and self-confidence in athletic performance of beach volleyball.

    Science.gov (United States)

    Kais, Kristjan; Raudsepp, Lennart

    2004-04-01

    This study considered the influence of competitive anxiety and self-confidence state responses upon athletic performance. 66 male beach volleyball players completed the translated and modified Competitive State Anxiety Inventory-2 which included the original intensity scale and a direction scale of Jones and Swain. Players' performance was scored from the video records using a standard rating scales. Correlations indicated scores on Direction subscale of modified Competitive State Anxiety Inventory-2 and Self-confidence were moderately positively (r=.27 to .51) correlated with different skill components and sum of skill components of beach volleyball. Stepwise multiple regressions indicated that, as anticipated, directional perceptions of cognitive and somatic anxiety and self-confidence were significant predictors of beach volleyball performance but accounted for only 42% of variance. Original Intensity subscales of somatic and cognitive anxiety did not predict performance. Findings support the notion that direction of anxiety responses must be taken into consideration when examining anxiety-performance association in sport.

  20. Factors associated to performance efficacy of technical-tactical actions in volleyball

    Directory of Open Access Journals (Sweden)

    William das Neves Salles

    2017-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n1p74   The aim of the study was to investigate the factors associated to performance efficacy of technical-tactical actions in volleyball. Based on the protocol of the Instrument for Technical and Tactical Performance Assessment in Volleyball (IAD-VB, 44.025 match actions performed by male and female athletes from u-15, u-16 and u-17 finalist teams of the 2010 Santa Catarina Volleyball Championship in Brazil were observed. Data were analyzed on SPPS 21 software using the logistic regression technique, adopting 5% significance level for the interpretation of results. Adjusted model explained 51.40% efficacy variance, and the factors associated with this variable were decision making, adjustment, efficiency, and competition level.

  1. Isolated and painless (? atrophy of the infraspinatus muscle: left handed versus right handed volleyball players

    Directory of Open Access Journals (Sweden)

    Thiago D. Gonçalves Côelho

    1994-12-01

    Full Text Available The suprascapular nerve originates from the upper trunk of the brachial plexus or less frequently from the root of C5. It runs a short way and crosses the suprascapular notch. It innervates the supraspinatus muscle and the acromioclavicular and glenohumeral joints. Then, it crosses the lateral edge of the spine of the scapula passing through the spinoglenoid notch, and innervates the infraspinatus muscle. These are potential sites of injury to the suprascapular nerve. Three cases of suprascapular nerve entrapment causing an isolated infraspinatus muscle atrophy in volleyball players were studied. It is suggested the hypothesis that the nature of the smash, in which the athlete uses the arm violently, more than does in volleyball service or in the art of reception, is the key to the pathogenesis of the lesion in volleyball players.

  2. Contact psychophysiological and neural functions with technical and tactical readiness volleyball

    Directory of Open Access Journals (Sweden)

    I.D. Glazyrin

    2013-06-01

    Full Text Available Set the level of neural development, psycho-physiological functions in highly skilled volleyball players. Defined technical and tactical preparedness highly skilled volleyball players in the competitive period of the annual cycle of training. The study involved six masters of sport and 8 candidates for the master of sports. That the quality of play activities and the successful execution of technical elements depend on functional mobility, strength and reactivity of nerve processes, associative thinking, memory and attention. The results, which may have a prognostic value. It is shown that the neurodynamic functions are genetically determined. It is recommended to use them for the initial recruitment and selection stages for sports improvement. The necessity influence the types of thinking, memory and attention in the training process of volleyball players.

  3. Analysis of male volleyball players' motor activities during a top level match.

    Science.gov (United States)

    Mroczek, Dariusz; Januszkiewicz, Aleksander; Kawczyński, Adam S; Borysiuk, Zbigniew; Chmura, Jan

    2014-08-01

    The present study aims to assess motor activity of volleyball players using an original video recording method developed by the authors. Twenty-eight volleyball players taking part in 4 matches of the Polish Volleyball League were examined. The recorded data were analyzed in view of the mean total distance covered by volleyball players on different court positions during a match, set, and rally. The results showed that volleyball players cover the mean total distance of 1221 ± 327 m (mean ± SD) in a 3-set match, and 1757 ± 462 m in a 4-set match. A statistically significant difference (p ≤ 0.005) was found between the distance covered by the middle blockers and setters, defenders, spikers, and libero players in a match and in a set. The study revealed a tendency to lengthen the distance by the players in the final sets, which is indicative of the extended time of individual rallies. The mean distance covered in a single rally amounted to 10.92 ± 0.9 m in 4 matches (between 9.12 and 12.56 m). Considering the limited size of the field of play, volleyball players cover relatively long distances during a match and individual sets, with the shortest distance covered by middle blockers, and the longest by setters. From a practical application point of view, detailed topographic analysis of a player's movements on the court as well as precise data on the time of activity and rest breaks provide the coach with valuable information on the ways of development of arrhythmic, changing and dynamic training loads.

  4. Training reduces catabolic and inflammatory response to a single practice in female volleyball players.

    Science.gov (United States)

    Eliakim, Alon; Portal, Shawn; Zadik, Zvi; Meckel, Yoav; Nemet, Dan

    2013-11-01

    We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Thirteen female, national team level, Israeli volleyball players (age 16.0 ± 1.4 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60 minutes of volleyball practice, before and after 7 weeks of training during the initial phase of the season. Training involved tactic and technical drills (20% of time), power and speed drills (25% of time), interval sessions (25% of time), endurance-type training (15% of time), and resistance training (15% of time). To achieve greater training responses, the study was performed during the early phase (first 7 weeks) of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor-I (IGF-I) and IGF-binding protein-3, the catabolic hormone cortisol, the proinflammatory marker interleukin-6 (IL-6), and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of vertical jump, anaerobic properties (peak and mean power by the Wingate Anaerobic Test), and predicted VO2max (by the 20-m shuttle run). Volleyball practice, both before and after the training intervention, was associated with a significant increase of serum lactate, GH, and IL-6. Training resulted in a significantly reduced cortisol response ([INCREMENT]cortisol: 4.2 ± 13.7 vs. -4.4 ± 12.3 ng · ml, before and after training, respectively; p volleyball practice. The results suggest that along with the improvement of power and anaerobic and aerobic characteristics, training reduces the catabolic and inflammatory response to exercise.

  5. Vertical jumping tests in volleyball: reliability, validity, and playing-position specifics.

    Science.gov (United States)

    Sattler, Tine; Sekulic, Damir; Hadzic, Vedran; Uljevic, Ognjen; Dervisevic, Edvin

    2012-06-01

    Vertical jumping is known to be important in volleyball, and jumping performance tests are frequently studied for their reliability and validity. However, most studies concerning jumping in volleyball have dealt with standard rather than sport-specific jumping procedures and tests. The aims of this study, therefore, were (a) to determine the reliability and factorial validity of 2 volleyball-specific jumping tests, the block jump (BJ) test and the attack jump (AJ) test, relative to 2 frequently used and systematically validated jumping tests, the countermovement jump test and the squat jump test and (b) to establish volleyball position-specific differences in the jumping tests and simple anthropometric indices (body height [BH], body weight, and body mass index [BMI]). The BJ was performed from a defensive volleyball position, with the hands positioned in front of the chest. During an AJ, the players used a 2- to 3-step approach and performed a drop jump with an arm swing followed by a quick vertical jump. A total of 95 high-level volleyball players (all men) participated in this study. The reliability of the jumping tests ranged from 0.97 to 0.99 for Cronbach's alpha coefficients, from 0.93 to 0.97 for interitem correlation coefficients and from 2.1 to 2.8 for coefficients of variation. The highest reliability was found for the specific jumping tests. The factor analysis extracted one significant component, and all of the tests were highly intercorrelated. The analysis of variance with post hoc analysis showed significant differences between 5 playing positions in some of the jumping tests. In general, receivers had a greater jumping capacity, followed by libero players. The differences in jumping capacities should be emphasized vis-a-vis differences in the anthropometric measures of players, where middle hitters had higher BH and body weight, followed by opposite hitters and receivers, with no differences in the BMI between positions.

  6. Comparison of Angiotensin Converting Enzyme (ACE gene polymorphisms elite basketball players and volleyball players

    Directory of Open Access Journals (Sweden)

    Emin Süel

    2015-09-01

    Full Text Available Aim: The purpose of this study is to research the differences of genotype polymorphism between the elite male and elite female basketball player, volleyball player and control group. Material and Methods: 58 basketball players (ages 24.25±4.99 years, height 188.22±12.31 cm and weight 80.62±16.34 kg, 64 volleyball players (ages 22.82±5.40 years, height 188.67±9.69 cm and weight 77.82±12.14 kg and 122 sedentary subjects (control group were participated randomly in the study. 5cc blood was taken control and control groups for measuring the ACE gene polymorphism. Chi-square and analysis of variance (ANOVA, Levene’s Tests, and frequencies of allele were used for statistical evaluation at significance level p0.05, basketball, volleyball and control group (p>0.05, male basketball, volleyball and control group (p>0.05, female basketball, volleyball and control group (p>0.05 and male and female athletes (p>0.05 respectively. There were no significance differences in male athletes between the genotype distribution and physical performance tests, such as 20m shuttle-run (F=1.31, vertical jump (F=0.22, and 20m sprint test (F=0.44. There were also no significance differences in female athletes between the genotype distribution and physical performance tests, such as 20m shuttle-run (F=2.03, vertical jump (F=0.10, and 20m sprint test (F=1.17. Conclusion: ACE polymorphism genotype distribution in terms of elite female and male volleyball players with elite female and male basketball players are the same.

  7. Tracking of ball and players in beach volleyball videos.

    Directory of Open Access Journals (Sweden)

    Gabriel Gomez

    Full Text Available This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points.

  8. Tracking of Ball and Players in Beach Volleyball Videos

    Science.gov (United States)

    Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

    2014-01-01

    This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

  9. [Eating habits of a group of professional volleyball players].

    Science.gov (United States)

    Gacek, Maria

    2011-01-01

    The aim of the research was an analysis of the eating habits of professional volleyball players according to their sex and age. The research has been carried out on a group of 210 men players and women players at the age of 13-25, representatives of sports clubs in Ostrołeka, Myślenice, Bydgoszcz and Warszawa. The research has revealed a limited realisation of rational diets by both men and women players. The most common mistakes made by them include a smaller number of meals during the day than recommended (especially among men), taking up training on empty stomach and insufficient frequency of consumption of dairy products, fish, vegetables and fruit. The research has also revealed excessive consumption of sweets, sweet sparkling drinks and fast food (mainly among men). The examined players to some extent only apply regular strategies of rehydration of their organisms. A high percentage of them do not pay attention to supplementation of liquids after an effort or they drink a lot of liquids at one time. The most frequently chosen drinks were mineral water and isotonic drinks. Supplementation was applied by a small percentage of the players, mainly men, who most often chose vitamins, Izostar, creatine, L-carnitine and HMB.

  10. Mineral legislations applicable to beach sand industry

    International Nuclear Information System (INIS)

    D'Cruz, Eric

    2016-01-01

    India has got a wealth of natural resources in different geological environs and shoreline placers form an important constituent of the natural resources. Large reserves of beach sand minerals, viz. imenite, rutile, leucoxene, zircon, sillimanite, garnet and monazite are the economic minerals in the coastal and inland placer sands. In the federal structure of India, the State Governments are the owners of minerals located within their respective boundaries. The State Governments grant the mineral concessions for all the minerals located within the boundary of the State, under the provisions of the Acts and Rules framed for the purpose. Though the mineral wealth is under the control of the State, the power for framing the rules for the grant of mineral concessions vastly rest with the Central Government. Since mineral concessions are often granted for a longer duration of thirty to fifty years or more, a historical perspective of these rules are imperative in understanding the issues involved with BSM mining industry. Under the Govt. of India Act, 1935, Regulation of Mines and Oilfields and Mineral Development was kept under Federal control, declared by Federal Law. The word 'Federal' was substituted by the word 'Dominion' by the India (Provincial Constitution) Order, 1947. No legislation was, however, enacted in pursuance of above power until after Independence. However, the Govt. on India made the Mining Concession (Central) Rules, 1939 for regulating grants of prospecting license

  11. Evaluation of the body bearing of high performance female volleyball players

    Directory of Open Access Journals (Sweden)

    Stech M.

    2010-09-01

    Full Text Available In the present paper the results of the study of body bearing in 12 high performance female volleyball players of polish team (TPS Rumia are presented. To estimate body bearing the New-York's test of the body bearing classification was used. The results of the study have shown that asymmetrical positions of volleyball players in the time of services and attacks are contributed to formed some asymmetrical disturbances of body bearing. At the majority of sportsmen it is exhibited in omitting the left brachium and the left blade, in a right-hand scoliosis, in the tendency to a platypodia. It requires use of special preventive and adjusting exercises.

  12. Biomechanical Assessment of the Strength of Volleyball Players in Different Stages of the Training Macrocycle

    Directory of Open Access Journals (Sweden)

    Śliwa Marcin

    2015-09-01

    Full Text Available Introduction. In order to help volleyball players achieve superior results, their coaches are constantly seeking new training methods. One of the methods used to improve the effectiveness of the training that is being implemented is conducting tests which make it possible to assess the player’s locomotor system in terms of its motor and biomechanical functions. The aim of the study was to determine the torque of the knee flexor and extensor muscles of volleyball players in three stages of the annual macrocycle.

  13. Oil sands tax expenditures

    International Nuclear Information System (INIS)

    Ketchum, K; Lavigne, R.; Plummer, R.

    2001-01-01

    The oil sands are a strategic Canadian resource for which federal and provincial governments provide financial incentives to develop and exploit. This report describes the Oil Sands Tax Expenditure Model (OSTEM) developed to estimate the size of the federal income tax expenditure attributed to the oil sands industry. Tax expenditures are tax concessions which are used as alternatives to direct government spending for achieving government policy objectives. The OSTEM was developed within the business Income Tax Division of Canada's Department of Finance. Data inputs for the model were obtained from oil sands developers and Natural Resources Canada. OSTEM calculates annual revenues, royalties and federal taxes at project levels using project-level projections of capital investment, operating expenses and production. OSTEM calculates tax expenditures by comparing taxes paid under different tax regimes. The model also estimates the foregone revenue as a percentage of capital investment. Total tax expenditures associated with investment in the oil sands are projected to total $820 million for the period from 1986 to 2030, representing 4.6 per cent of the total investment. 10 refs., 2 tabs., 7 figs

  14. Bituminous sands : tax issues

    International Nuclear Information System (INIS)

    Patel, B.

    2004-01-01

    This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs

  15. Risk factors associated with self-reported symptoms of digital ischemia in elite male volleyball players in the Netherlands.

    Science.gov (United States)

    van de Pol, D; Kuijer, P P F M; Langenhorst, T; Maas, M

    2014-08-01

    One in every four elite male volleyball players in the Netherlands reported blue or pale digits in the dominant hand. Little is known about risk factors. To assess whether personal-, sports-, and work-related risk factors are associated with these symptoms in these volleyball players, a survey was performed among elite male volleyball players in the Dutch national top league and in the Dutch beach volleyball team. The questionnaire assessed the presence of symptoms and risk factors. Binary logistic regression was performed to calculate odds ratios (ORs). A total of 99 of the 107 athletes participated - a response rate of 93%. Two sports-related risk factors were associated with symptoms of blue or pale digits: 18-30 years playing volleyball [OR = 6.70; 95% confidence interval (CI) 1.12-29.54] and often/always performing weight training to increase dominant limb strength (OR = 2.70; 95% CI 1.05-6.92). No significant other sports-, personal-, or work-related risk factors were found. Playing volleyball for more than 17 years and often/always performing weight training to increase dominant limb strength were independently associated with an increased risk on ischemia-related complaints of the dominant hand in elite male volleyball players. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Effects of prolonged intensive training on the resting levels of salivary immunoglobulin A and cortisol in adolescent volleyball players.

    Science.gov (United States)

    Li, T L; Lin, H C; Ko, M H; Chang, C K; Fang, S H

    2012-10-01

    Concerns have been raised regarding the effects of prolonged intensive training on adolescent athletes. This study investigated the differences in mucosal immune functions and stress responses between intensively trained male adolescent volleyball players and age-matched sedentary controls. Twelve male volleyball players (16.5 [0.7] years of age) and sixteen healthy sedentary male volunteers (17.1 [0.6] years of age) participated in this study. Volleyball players were engaged in regular and year-round training. Unstimulated saliva samples were collected from volleyball players during the high-intensity training period and from the counterparts at the same timepoints after at least 18 hours of rest. Concentrations of salivary total protein, secretory immunoglobulin A (SIgA), cortisol, and lactoferrin were measured. Results of this study revealed that the SIgA concentrations and the ratio of SIgA/total protein in volleyball players were significantly lower compared with those in sedentary controls. However, the salivary cortisol concentrations and the ratio of cortisol/total protein in volleyball players were markedly higher compared with those in sedentary controls. No significant difference was observed in lactoferrin levels between volleyball players and sedentary controls. The findings of this study suggest that the prolonged intensive training may elicit a sustained stress and induce a suppressive effect on mucosal immunity in regularly and intensively trained adolescent athletes.

  17. Sand Dunes with Frost

    Science.gov (United States)

    2004-01-01

    9 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of frost-covered sand dunes in the north polar region of Mars in early spring, 2004. The dunes indicate wind transport of sand from left to right (west to east). These landforms are located near 78.1oN, 220.8oW. This picture is illuminated by sunlight from the lower left and covers an area about 3 km (1.9 mi) across.

  18. Management of Sport Injuries with Korean Medicine: A Survey of Korean National Volleyball Team

    Directory of Open Access Journals (Sweden)

    Changsop Yang

    2016-01-01

    Full Text Available The purpose of this study was to report the current state of Korean medicine (KM treatment on sports injury by implementing survey with volleyball team medical doctors participating in 2013-2014 season. Six KM doctors completed a questionnaire that includes injury parameters: type, location, situation, and pain scores. We collected 166 injury cases from 94 Korean male and female national volleyball players. Knee (25.9%, low back (13.3%, elbow, and ankle (8.4% injuries were most common. Joint (41.6% and muscle (30.7% were major injured tissues. KM team medical doctors utilized acupuncture (40.4%, chuna manual therapy (16.0%, physical therapy (15.2%, taping (9.0%, and cupping (7.8% to treat volleyball injuries. Any types of medications were used infrequently. Additional physical and exercise therapy were preferred after receiving acupuncture (both 46.9%. This study presented the preliminary injury profile of Korean elite volleyball players. Injury and treatment parameters could be useful to build advanced KM model in sport medicine.

  19. Blocking landing techniques in volleyball and the possible association with anterior cruciate ligament injury.

    Science.gov (United States)

    Zahradnik, David; Jandacka, Daniel; Holcapek, Michal; Farana, Roman; Uchytil, Jaroslav; Hamill, Joseph

    2018-04-01

    The number and type of landings performed after blocking during volleyball matches has been related to the potential risk of ACL injury. The aim of the present study was to determine whether gender affects the frequency of specific blocking landing techniques with potential risk of ACL injury from the perspective of foot contact and subsequent movement after the block used by volleyball players during competitive matches. Three matches involving four female volleyball teams (fourteen sets) and three matches involving four male volleyball teams (thirteen sets) in the Czech Republic were analyzed for this study. A Pearson chi-square test of independence was used to detect the relationship between gender and different blocking techniques. The results of the present study showed that gender affected single-leg landings with subsequent movement in lateral direction and double-leg landings. Although the total number of landings was lower for male athletes than for female athletes, a larger portion of male athletes demonstrated single leg landings with a subsequent movement than female athletes. Single leg landings with a subsequent movement have a higher potential risk of ACL injury.

  20. Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

    Science.gov (United States)

    Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

    2015-03-01

    This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

  1. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    Science.gov (United States)

    van Ark, M; Docking, S I; van den Akker-Scheek, I; Rudavsky, A; Rio, E; Zwerver, J; Cook, J L

    2016-02-01

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. The prevention of musculoskeletal injuries in volleyball : the systematic development of an intervention and its feasibility

    NARCIS (Netherlands)

    Gouttebarge, Vincent; van Sluis, Marije; Verhagen, Evert; Zwerver, Johannes

    2017-01-01

    BACKGROUND: A scientific research project has started in the Netherlands with the aim of developing and implementing an evidence-based intervention to prevent the occurrence of musculoskeletal injuries among young and adult recreational volleyball players. This article describes (i) the systematic

  3. Different temporal bases for body and arm movements in volleyball serve reception

    NARCIS (Netherlands)

    Benerink, N. H.; Bootsma, R. J.; Zaal, F. T. J. M.

    2015-01-01

    In many sports, successfully intercepting a ball requires players to move both their body and their arms. Yet, studies of interception typically focus on one or the other. We performed an analysis of the moments of first foot and arm movements of elite-level volleyball players during serve

  4. Effects of Classwide Peer Tutoring on the Performance of Sixth Grade Students during a Volleyball Unit

    Science.gov (United States)

    Ayvazo, Shiri; Ward, Phillip

    2009-01-01

    This investigation examined the effects of Classwide Peer Tutoring (CWPT), a variation of peer tutoring on the volleyball skills of four 6th grade middle school students purposefully selected from an intact class of 21 students. Participants were average to low skilled males and females. A single subject A-B-A-B withdrawal design was used to…

  5. Role of Uniforms in the Body Image of Female College Volleyball Players

    Science.gov (United States)

    Steinfeldt, Jesse A.; Zakrajsek, Rebecca A.; Bodey, Kimberly J.; Middendorf, Katharine G.; Martin, Scott B.

    2013-01-01

    Female student athletes often desire a muscular body to be successful in sport, but this body type does not conform to traditional cultural norms of femininity. In this study, the authors qualitatively examined the experiences of female intercollegiate volleyball players to better understand their beliefs about their bodies--both as athletes and…

  6. Preventing musculoskeletal injuries among recreational adult volleyball players : design of a randomised prospective controlled trial

    NARCIS (Netherlands)

    Gouttebarge, Vincent; Zwerver, Johannes; Verhagen, Evert

    2017-01-01

    BACKGROUND: Both acute and overuse injuries are common among recreational volleyball players, especially finger/wrist, ankle, shoulder and knee injuries. Consequently, an intervention ('VolleyVeilig') was developed to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle

  7. The prevention of musculoskeletal injuries in volleyball: the systematic development of an intervention and its feasibility

    NARCIS (Netherlands)

    Gouttebarge, Vincent; van Sluis, Marije; Verhagen, Evert; Zwerver, Johannes

    2017-01-01

    A scientific research project has started in the Netherlands with the aim of developing and implementing an evidence-based intervention to prevent the occurrence of musculoskeletal injuries among young and adult recreational volleyball players. This article describes (i) the systematic development

  8. Shoulder pain among high-level volleyball players and preseason features.

    Science.gov (United States)

    Forthomme, Benedicte; Wieczorek, Valerie; Frisch, Anne; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2013-10-01

    The main goal of this prospective study was to identify the most significant intrinsic risk factors for shoulder pain by measuring strength developed by shoulder rotators and by carrying out various morphostatic assessments. Sixty-six players (mean ± SD age = 24 ± 5 yr) were recruited from nine volleyball teams from the first and second divisions (34 men and 32 women) to participate in the study. Before the start of the volleyball season, all the participants completed a preseason questionnaire and underwent both a bilateral isokinetic evaluation of the shoulders and morphostatic measurements. During the subsequent 6 months of the competition period, the players reported through a weekly questionnaire any shoulder pain experienced. During the ongoing season, 23% (15 of 66 players) of the volleyball players experienced dominant shoulder pain. Interestingly, participants who reported a history of dominant shoulder pain were found to have nine times higher risk of suffering further pain in their dominant shoulder. The eccentric maximal strength developed by the internal and external rotators was found to represent a protective factor in the volleyball players (respective odds ratios = 0.946, P = 0.01 and 0.94, P = 0.05). No risk factors were found among the shoulder morphostatic measurements. In our study, the evaluation of shoulder rotator muscle strength through isokinetic assessment, especially eccentric mode, appeared to be the most contributing parameter to identify risk factors for shoulder pain. This evaluation should allow to better identify players at risk.

  9. A COMPARATIVE STUDY OF PERSONALITY OF INTERNATIONAL VOLLEYBALL PLAYERS OF BRAZIL AND INDIA

    Directory of Open Access Journals (Sweden)

    Govind Kadam

    2010-06-01

    Full Text Available The main objective was to study the personality of the volleyball players of India. All the players of Indian team and the players of Brazil team, who came for FIVB Men Volleyball World Championship held at Pune in August 2009, were selected for the study. They were administered the Cattell’s 16 PF questionnaire. The results wereanalyzed with the help of ‘t’ test which showed that there are significant differences found between Indian volleyball players and Brazilian Volleyball players on seven factors but not on nine factors of 16 PF Questionnaire. Indian players scored high on factor ‘F’, factor ‘I’ and factor ‘M’ whereas Brazilian players have scored high on factor ‘B’, factor ‘G’, factor ‘H’ and factor ‘L’. Indian players scored low on Factor B which means that they tend to be slow to learn and grasp and they were dull as compared with Brazilian team, and gives concrete and literal interpretation. This dullness simply represents poor functioning.

  10. Preventing musculoskeletal injuries among recreational adult volleyball players: design of a randomised prospective controlled trial

    NARCIS (Netherlands)

    Gouttebarge, Vincent; Zwerver, Johannes; Verhagen, Evert

    2017-01-01

    Background: Both acute and overuse injuries are common among recreational volleyball players, especially finger/wrist, ankle, shoulder and knee injuries. Consequently, an intervention ('VolleyVeilig') was developed to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle

  11. Rehabilitation protocol for patellar tendinopathy applied among 16- to 19-year old volleyball players.

    Science.gov (United States)

    Biernat, Ryszard; Trzaskoma, Zbigniew; Trzaskoma, Lukasz; Czaprowski, Dariusz

    2014-01-01

    The aim of the study was to investigate the efficacy of rehabilitation protocol applied during competitive period for the treatment of patellar tendinopathy. A total of 28 male volleyball players were divided into two groups. Fifteen from experimental group (E) and 13 from control group (C) fulfilled the same tests 3 times: before the training program started (first measurement), after 12 weeks (second measurement) and after 24 weeks (third measurement). The above-mentioned protocol included the following: USG imagining with color Doppler function, clinical testing, pain intensity evaluation with VISA-P questionnaire, leg muscle strength and power and jumping ability measurements. The key element of the rehabilitation program was eccentric squat on decline board with additional unstable surface. The essential factor of the protocol was a set of preventive functional exercises, with focus on eccentric exercises of hamstrings. Patellar tendinopathy was observed in 18% of the tested young volleyball players. Implementation of the presented rehabilitation protocol with eccentric squat on decline board applied during sports season lowered the pain level of the young volleyball players. Presented rehabilitation protocol applied without interrupting the competitive period among young volleyball players together with functional exercises could be an effective method for the treatment of patellar tendinopathy.

  12. Exploring Changes to a Teacher's Teaching Practices and Student Learning through a Volleyball Content Knowledge Workshop

    Science.gov (United States)

    Kim, Insook

    2016-01-01

    This paper describes how improving a teacher's content knowledge changes his teaching practices and its subsequent effects on student learning during a middle school volleyball instructional unit. The study was designed to challenge teacher educators' thinking about the importance of in-depth content knowledge for effective teaching by…

  13. Spike the PCHA! Overuse injury of the Posterior Circumflex Humeral Artery in elite volleyball

    NARCIS (Netherlands)

    van de Pol, D.

    2016-01-01

    In 1993, professor Reekers of the Academic Medical Center (AMC) Radiology department was the first to describe a traumatic aneurysm of the posterior circumflex humeral artery (PCHA) in a volleyball player, suggesting a causal relationship. Fifteen years later, between 2008 and 2010, several elite

  14. The Effect of Movement Imagery Training on Learning Forearm Pass in Volleyball

    Science.gov (United States)

    Ay, Khitam Mousa; Halaweh, Rami Saleh; Al-Taieb, Mohammad Abu

    2013-01-01

    This study investigates the effect of movement imagery on learning the forearm pass in volleyball. Twenty four mail students from Physical Education Factuly at Jordan University (19 ± 0.5) years of age. After Completed the Movement Imagery Questionnaire-Revised (MIQ-R; Hall & Martin, 1997) the subjects randomly divided into two groups,…

  15. Comparison of Total Antioxidant Capacity Oxidative Stress and Blood Lipoprotein Parameters in Volleyball Players and Sedentary

    Science.gov (United States)

    Gokhan, Ismail

    2013-01-01

    This study aims to measure, then compare sedentary blood lipoproteins, oxidant- antioxidant state and oxidative stress index in volleyball players. The experimental group of the research consists of regularly practising 20 boys between the ages of 12 and 17, and the control group comprises 32 children practising no particular sports branch, 12 of…

  16. Comparison of Three Instructional Approaches to Enhance Tactical Knowledge in Volleyball among University Students

    Science.gov (United States)

    Vande Broek, Gert; Boen, Filip; Claessens, Manu; Feys, Jos; Ceux, Tanja

    2011-01-01

    This study investigated the decision-making process of three instructional groups (i.e., teacher-centered, student-centered with tactical questioning and student-centered without tactical questioning) in practical courses in volleyball among university students. All students (N = 122) performed a Tactical Awareness task on the correctness of the…

  17. Cohesion and Trauma: An Examination of a Collegiate Women's Volleyball Team

    Science.gov (United States)

    Fletcher, Teresa B.; Meyer, Barbara B.

    2009-01-01

    This study examined the effects of Adventure Based Counseling (i.e., a low-element challenge program) on the cohesion of a collegiate women's volleyball team. Results suggest postintervention improvements in team cohesion. The support created in the challenge experience also transferred to the players helping one another to grieve the untimely…

  18. Features of use of combinational circuits play in attack during volleyball matches

    Directory of Open Access Journals (Sweden)

    B. O. Artemenko

    2013-12-01

    Full Text Available Purpose : To characterize tactical formation game action in the attack and the frequency of execution of power and tactical (planning innings volleyball players of different skill levels. Material and methods: The analyzed video recordings of volleyball matches with the strongest teams of the world: Brazil, Russia, USA, Cuba, Italy, the leading volleyball championship teams of Russia and Ukraine. The features of tactical formation game. Results: It was established that the binders players strongest teams and club teams in the world is used in the organization of attack more variety of tactical combinations. So almost equally, the following combinations: Rise, Pipe and Zone (13.4 % 12.6 % 11.5%. Ukrainian binders players prefer only combinations Rise - 23%; Pipe - 2%; Zone - 2.5%, respectively. Distribution innings for planning and power for Ukrainian teams: 59.7 % versus 40.3% and 27.5 % versus 72.5 %, respectively, the strongest national teams in the world. Conclusions: The features of tactical formation attack suggest the best technical - tactical training players tie the strongest teams in the world and the whole team. Also leading the team to the world is much more likely to use the power supply, which indicates the nature of the power of world volleyball.

  19. THE MODEL CHARACTERISTICS OF JUMP ACTIONS STRUCTURE OF HIGH PERFORMANCE FEMALE VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Stech M.

    2012-12-01

    Full Text Available The purpose of this study was to develop generalized and individual models of the jump actions of skilled female volleyball players. The main prerequisite for the development of the jump actions models were the results of our earlier studies of factor structure of jump actions of 10 sportswomen of the Polish volleyball team "Gedania" (Premier League in the preparatory and competitive periods of the annual cycle of preparation. The athletes age was 22.0 +- 2.9 years, the sports experience - 8.1 +- 3.1 years, body height - 181.9 +- 8.4 years and body weight - 72.8 +- 10.8 kg. Mathematical and statistical processing of the data (the definition of M ± SD and significant differences between the samples was performed using a standard computer program "STATISTICA 7,0". Based on the analysis of the factor structure of 20 jump actions of skilled women volleyball players determined to within 5 of the most informative indexes and their tentative values recommended for the formation of a generalized model of this structure. Comparison of individual models of jump actions of skilled women volleyball players with their generalized models in different periods of preparation can be used for the rational choice of means and methods for the increasing of the training process efficiency.

  20. Nonoperative Management and Novel Imaging for Posterior Circumflex Humeral Artery Injury in Volleyball

    NARCIS (Netherlands)

    van de Pol, Daan; Planken, R. Nils; Terpstra, Aart; Pannekoek-Hekman, Marja; Kuijer, P. Paul F. M.; Maas, Mario

    2017-01-01

    We report on a 34-yr-old male elite volleyball player with symptomatic emboli in the spiking hand from a partially thrombosed aneurysm of the posterior circumflex humeral artery (PCHA) in his dominant shoulder. At initial diagnosis and follow-up, a combination of time-resolved and high-resolution

  1. Identification of a effective cooperation model in the game positioning in a volleyball game

    Directory of Open Access Journals (Sweden)

    Leszek Mazur

    2017-06-01

    Full Text Available Purpose: The paper is aimed at identification of a model which shows the effective cooperation in the game positioning (exactly in receiving-passing the ball in a volleyball game. Design/methodology/approach: The original research method is used in this thesis which is called pragmatic unique case study. The research is aimed at observation USA team playing volleyball during The Olympic Games in Rio de Janeiro 2016.  Findings: There is a cooperation model in receiving and passing the ball among USA volleyball team players found, based on the observation. There are also other cooperation models used by teams.                     Research and practical limitations/implications: Based in the research I can tell that there are different models of cooperation in the game positioning in volleyball. The teams which are the most effective use different models of cooperation while playing.                     Originality/value: The paper is original and leads to think about the identification of the process of cooperation in team games. More research in this field is recommended.

  2. Comparative study of anthropometric variables in female classical ballet dancers, volleyball players and physically active subjects

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Vaz

    2009-01-01

    Full Text Available The objective of this study was to compare anthropometric variables (body weight, height, and percent body fat and plantarflexion and dorsiflexion range of motion (ROM between three different groups of women: classical ballet dancers (n=14, volleyball players (n=22 and physically active subjects (n=13. The assumption was that different functional requirements should produce differences in the anthropometric variables and ROM between the three groups. Body weight and height were higher in volleyball players (66.42 ± 5.8 kg; 174.77 ± 5.6 cm, followed by physically active women (59.93 ±10.3 kg; 164 ± 7.5 cm and ballet dancers (49.25 ± 4.5 kg; 157.03 ± 3.6 cm (p<0.05. Percent body fat was higher in physically active women (30.67 ± 4.6% compared to theother two groups, which showed similar percentages (volleyball players: 24.93 ± 4.1%; ballet dancers: 21.94 ± 4.3%. The three groups were similar in terms of total ankle ROM and active dorsiflexion ROM between the right and left sides. However, plantarflexion ROM was higher in ballet dancers (~83°, followed by physically active women (~68° and volleyball players who presented the smallest ROM (~60°. The different requirements imposed by the three distinct physical activities seem to be responsible for changes in some of the anthropometric variables and ankle joint ROM.

  3. Sand (CSW4)

    CSIR Research Space (South Africa)

    Estuarine and Coastal Research Unit

    1982-12-01

    Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

  4. Inland drift sand landscapes

    NARCIS (Netherlands)

    Fanta, J.; Siepel, H.

    2010-01-01

    Man has had a complex relationship with inland drift sands through the ages. For some centuries these landscapes were seen as a threat to society, especially agriculture and housing. At present we conserve these landscapes as important Natura 2000 priority habitats. In this book you may find these

  5. "Ballistic Six" Upper-Extremity Plyometric Training for the Pediatric Volleyball Players.

    Science.gov (United States)

    Turgut, Elif; Cinar-Medeni, Ozge; Colakoglu, Filiz F; Baltaci, Gul

    2017-09-19

    The Ballistic Six exercise program includes commonly used upper-body exercises, and the program is recommended for overhead throwing athletes. The purpose of the current study was to investigate the effects of a 12-week the Ballistic Six upper-extremity plyometric training program on upper-body explosive power, endurance, and reaction time in pediatric overhead athletes. Twenty-eight female pediatric volleyball players participated in the study. The participants were randomly divided into 2 study groups: an intervention group (upper-extremity plyometric training in addition to the volleyball training; n = 14) and a control group (the volleyball training only; n = 14). All the participants were assessed before and after a 12-week training program for upper-body power, strength and endurance, and reaction time. Statistical comparison was performed using an analysis of variance test. Comparisons showed that after a 12-week training program, the Ballistic Six upper-body plyometric training program resulted in more improvements in an overhead medicine ball throwing distance and a push-up performance, as well as greater improvements in the reaction time in the nonthrowing arm when compared with control training. In addition, a 12-week training program was found to be effective in achieving improvements in the reaction time in the throwing arm for both groups similarly. Compared with regular training, upper-body plyometric training resulted in additional improvements in upper-body power and strength and endurance among pediatric volleyball players. The findings of the study provide a basis for developing training protocols for pediatric volleyball players.

  6. On Pluvial Compaction of Sand

    DEFF Research Database (Denmark)

    Jacobsen, Moust

    At the Institute of Civil Engineering in Aalborg model tests on dry sand specimens have been carried out during the last five years. To reduce deviations in test results, the sand laying technique has been carefully studied, and the sand mass spreader constructed. Preliminary results have been...

  7. Environmental Impacts of Sand Exploitation. Analysis of Sand Market

    Directory of Open Access Journals (Sweden)

    Marius Dan Gavriletea

    2017-06-01

    Full Text Available Sand is an indispensable natural resource for any society. Despite society’s increasing dependence on sand, there are major challenges that this industry needs to deal with: limited sand resources, illegal mining, and environmental impact of sand mining. The purpose of this paper is twofold: to present an overview of the sand market, highlighting the main trends and actors for production, export and import, and to review the main environmental impacts associated with sand exploitation process. Based on these findings, we recommend different measures to be followed to reduce negative impacts. Sand mining should be done in a way that limits environmental damage during exploitation and restores the land after mining operations are completed.

  8. Dynamic load indicators for take-off-landing sequence in blocks and attacks of elite female volleyball players.

    Science.gov (United States)

    Kabaciński, Jarosław; Dworak, Lechosław Bogdan; Murawa, Michał; Rzepnicka, Agata

    2016-01-01

    Dynamic loads during landings determined by the ground reaction forces (GRFs) may elaborate internal loads and increase the risk of overload knee injuries as a result of performing volleyball jumps many times. The study dealt with a biomechanical assessment of dynamic load indicators in female volleyball players for the motion sequence of take-off-landing in blocks and attacks. Twelve professional female volleyball players participated in the study. Blocks and attacks were filmed by two cameras. GRFs vs. time graphs were recorded with the use of a force platform. Values of dynamic load indicators in terms of the relations of peak of vertical component of GRF, build-up index of this force (BIF), and power output (P) during landing to the vGRF, BIF and P during take-off (L/T) were calculated. The statistically significant ( p volleyball players.

  9. High prevalence of jumper's knee and sonographic changes in Swedish elite junior volleyball players compared to matched controls

    OpenAIRE

    Gisslen, K; Gyulai, C; Soderman, K; Alfredson, H

    2005-01-01

    Background: Jumper's knee is a common and troublesome condition among senior volleyball players, but its prevalence among elite junior players compared to matched non-sports active controls is not known.

  10. SandBlaster: Reversing the Apple Sandbox

    OpenAIRE

    Deaconescu, Răzvan; Deshotels, Luke; Bucicoiu, Mihai; Enck, William; Davi, Lucas; Sadeghi, Ahmad-Reza

    2016-01-01

    In order to limit the damage of malware on Mac OS X and iOS, Apple uses sandboxing, a kernel-level security layer that provides tight constraints for system calls. Particularly used for Apple iOS, sandboxing prevents apps from executing potentially dangerous actions, by defining rules in a sandbox profile. Investigating Apple's built-in sandbox profiles is difficult as they are compiled and stored in binary format. We present SandBlaster, a software bundle that is able to reverse/decompile Ap...

  11. Physical parameters and performance values in starters and non-starters volleyball players: A brief research note

    OpenAIRE

    Marques, M.C.; Marinho, D.A.

    2009-01-01

    The aim of this paper was to investigate the anthropometric and strength characteristics of elite male volleyball athletes and determines if differences exist in these characteristics between starters (S) and non-starters players (NS). A group of 22 professional male team volleyball players participated in the study and the players were categorized as S (n= 13) and NS (n= 9). Anthropometric characteristics, countermovement jump, overhead medicine ball throwing and maximal dynamic strength wer...

  12. Evaluation of the impact of the filing on the match results in qualifying for ME 2017 men's volleyball.

    OpenAIRE

    Dopita, Michal

    2017-01-01

    Title of the thesis Evaluation of the impact of service on the match result in qualification for Men's European Volleyball Championship 2017 Abstract The aim of this thesis is to evaluate the influence of service on the match result in qualification for the 2017 Men's Volleyball European Championship, using indirect video monitoring, and trace the success rate and frequency of individual types of services. Our intention is to show the importance of this individual game activity in a match wit...

  13. Oil sands supply outlook

    International Nuclear Information System (INIS)

    Dunbar, R.

    2004-01-01

    In March 2004, The Canadian Energy Research Institute released a report on the expected future supply from Alberta's oil sands. The report indicates that the future for the already well-established oil sands industry is promising, particularly given the outlook for oil prices. The challenges facing the industry include higher industry supply costs and the need for innovative commercial and technological solutions to address the risks of irregularities and changes in crude oil prices. In 2003, the industry produced 874 thousand barrels per day of synthetic crude oil and unprocessed crude bitumen. This represents 35 per cent of Canada's total oil production. Current production capacity has increased to 1.0 million barrels per day (mbpd) due to new projects. This number may increase to 3.5 mbpd by 2017. Some new projects may be deferred due to the higher raw bitumen and synthetic crude oil supply costs. This presentation provided supply costs for a range of oil sands recovery technologies and production projections under various business scenarios. tabs., figs

  14. Liquefaction resistance of calcareous sands

    International Nuclear Information System (INIS)

    Sandoval Vallejo, Eimar

    2012-01-01

    Calcareous sands are unique in terms of their origin, mineralogy, shape, fragility and intra particle porosity. This article presents results from an experimental program carried out to study the liquefaction resistance of a calcareous sand retrieved from Cabo Rojo at Puerto Rico. The experimental program included mineralogical characterization, index properties, and undrained cyclic triaxial tests on isotropically consolidated reconstituted samples. Due to the large variation in the calcareous sand properties, results are compared with previous researches carried out on other calcareous sands around the world. Results showed a wide range in the liquefaction resistance of the studied calcareous sands. Cabo Rojo sand experienced greater liquefaction resistance than most of the calcareous sands used for comparison. Important differences in the excess pore pressure generation characteristics were also found.

  15. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

  16. Oil sands development update

    International Nuclear Information System (INIS)

    1999-01-01

    A detailed review and update of oil sands development in Alberta are provided covering every aspect of the production and economic aspects of the industry. It is pointed out that at present oil sands account for 28 per cent of Canadian crude oil production, expected to reach 50 per cent by 2005. Based on recent announcements, a total of 26 billion dollars worth of projects are in progress or planned; 20 billion dollars worth of this development is in the Athabasca area, the remainder in Cold Lake and other areas. The current update envisages up to 1,800,000 barrels per day by 2008, creating 47,000 new jobs and total government revenues through direct and indirect taxes of 118 billion dollars. Provinces other than Alberta also benefit from these development, since 60 per cent of all employment and income created by oil sands production is in other parts of Canada. Up to 60 per cent of the expansion is for goods and services and of this, 50 to 55 per cent will be purchased from Canadian sources. The remaining 40 per cent of the new investment is for engineering and construction of which 95 per cent is Canadian content. Aboriginal workforce by common consent of existing operators matches regional representation (about 13 per cent), and new developers are expected to match these standards. Planned or ongoing development in environmental protection through improved technologies and optimization, energy efficiency and improved tailings management, and active support of flexibility mechanisms such as emission credits trading, joint implementation and carbon sinks are very high on the industry's agenda. The importance of offsets are discussed extensively along with key considerations for international negotiations, as well as further research of other options such as sequestration, environmentally benign disposal of waste, and enhanced voluntary action

  17. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  18. The effect of spiritual intelligence on quality of sleep and attention of skilled volleyball players

    Directory of Open Access Journals (Sweden)

    sodabeh ghadami

    2017-05-01

    Full Text Available Spiritual intelligence is something more than mental ability and connects an individual to beyond. The aim of this study was to assess the effect of spiritual intelligence on sleep quality and attention of skilled volleyball players.  Therefore 116 (76 female, 40 male volleyball players of Mobarakeh county in Isfahan who had participated in regional competitions were selected. Abdollazadeh’s Spiritual Intelligence Questionnaire, Pittsburgh Sleep Quality, and Mari shook Test were used to measure the data.  Results of path analysis showed that spiritual intelligence affects both sleep quality and attention. Moreover, the quality of sleep mediated the effect of spiritual intelligence on attention, and the results showed the appropriateness of structural equation model fit.

  19. Analysis the percentage frequency to estimate Volleyball´s performance

    Directory of Open Access Journals (Sweden)

    Santiago Calero-Morales

    2012-12-01

    Full Text Available The study analyzes the percentage frequency as a mathematical model used to estimate the international volleyball performance. Based on the description of its practical objectives, the paper shows some positive and negative characteristics of the equation, characteristics that affect decision making by the coach. Three studies were conducted involving a population of 42 games in volleyball, men's youth category, 10 game of 13 possible belonging to the Final round of 2006 FIVB World League, and a ranked players in the qualifying phase of the 2006 World League with 48 games as population. The investigation determined that the percentage frequency is a simple computer model that defines a value perfectly isolated from reality, but does not model correctly all variables that significantly influence the final performance, creating false interpretations of reality.

  20. DIFFERENCES IN MOTOR STATUS OF CHILDREN OF DIFFERENT SEX IN SCHOOL VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Maja Batez

    2013-07-01

    Full Text Available On a sample of 45 children (25 girls and 20 boys age of 9 to 11, who have been training volleyball (one to three years in the club "Sportisimo pajp" in Novi Sad, were applied four motor tests. The aim of this research was to determine differences in the motor status of children of different sex in the school volleyball. Multivariate analysis of variance (MANOVA determined a statistically significant difference in the whole system of analyzed motor variables depending on the sex on studied sample of child¬ren. Univariate analysis of variance (ANOVA showed that girls had better results in va¬riables of flexibility and agility. Boys are better in standing long jump, while sta¬tistically significant differences between means in the speed of alternative movements between girls and boys the not found.

  1. Effect of Age Group on Technical-Tactical Performance Profile of the Serve in Men's Volleyball.

    Science.gov (United States)

    García-de-Alcaraz, Antonio; Ortega, Enrique; Palao, José M

    2016-10-01

    The aim of this study was to analyze the technical-tactical performance profile of the serve for various age groups and categories of competition in men's volleyball. The sample comprised 13,262 serves performed by 986 players in 299 sets observed in various categories of competition (U-14, U-16, U-19, national senior, and international senior). An observational design was used. The variables studied were category of competition, type of execution, and serve performance. The results showed that for higher age groups (senior categories), there were significantly fewer jump serves and poorer serve performance, regardless of players' maturity and training development. The use of the jump serves increased the serve risk while attempting to hinder the organization of the opponent attack. This paper discusses the serve evolution and the implications on the training process at the different age groups in men's volleyball. © The Author(s) 2016.

  2. Use of Nutritional Supplements by High School Football and Volleyball Players

    Science.gov (United States)

    Mason, Melanie A; Giza, Matthew; Clayton, Lori; Lonning, Jim; Wilkerson, Rick D

    2001-01-01

    The known use of performance enhancing agents by athletes has occurred throughout history. In the 1960s and 1970s steroids and amphetamines were the supplements most often used. Now athletes are turning to supplements that are either natural or stimulate the release of natural hormones. The purpose of this study is to evaluate the prevalence of use of nutritional supplements among high school football and volleyball players. This study surveyed 495 male football players and 407 female volleyball players from 20 high schools in Northwest Iowa. These athletes completed anonymous surveys and returned them to their coaches. Results showed that 8% of the male athletes and 2% of the female athletes were using supplementation. Supplements used included creatine, androstiendione, HMB, amino acids, DHEA, phosphogen, weight gainer 1850, Tribulus, muscle plus, multivitamins, calcium, GABA, and Shaklee Vita Lea and Physique. PMID:11813950

  3. THE IMPACT OF ANTHROPOMETRIC CHARACTERISTICS ON MANIFESTATION OF EXPLOSIVE STRENGTH IN VOLLEYBALL PLAYERS AGED 13 YEARS

    Directory of Open Access Journals (Sweden)

    Goran Nesic

    2006-04-01

    Full Text Available With the aim to investigate the plyometric training model used for the increase of explosive strength type (the vertical jump, an experimental research was carried out, drawing a sample of 40 volleyball players at the cadet level. For the purpose of this research, we applied nine anthropometric characteristics, which made the predictor system of variables. For the assessment of explosive strength, three tests were performed. The data were processed by descriptive and regression analyses. Based on the findings of the research and the discussion, one could unfailingly conclude that the applied system of anthropometric characteristics, as a predictor, has a significant impact on manifestation of explosive strength in volleyball players, aged 13 years, that is, it is possible to predict results of the tests of explosive strength based on the measures of anthropometric status of examinees.

  4. Effect Of Plyometric Training On Vertical Jump Performance And Neuromuscular Adaptation In Volleyball Player

    Directory of Open Access Journals (Sweden)

    Dara Hosseini

    2012-12-01

    Full Text Available The purpose of this study was to examine the effectiveness of 12-week plyometric training on vertical jump performance (Vj, maximal surface EMG, M-wave amplitude, M�wave latency, and nerve conduction velocity (NCV in men volleyball player. Thirty junior high school volleyball players' volunteers (age: 17.53� 0.74; Height: 177.67� 3.14; Weight: 61.31 � 5.32 were divided into plyometric training [PT] (n=15 and control group[c] (n=15. PT group trained so.w' but C group didn't participate in this training. Both groups were pre- and post tested in EMG, M-wave parameters, NCV and Vj test. Tow way ANOVA (group*time interaction and Bonferroni post hoes test demonstrated significant differences (P

  5. [Anthropometrical profile of Brazilian junior volleyball players for different sports requirement levels].

    Science.gov (United States)

    Fonseca-Toledo, Cláudio; Roquetti, Paula; Fernandes-Filho, José

    2010-12-01

    This study was aimed at investigating the anthropometrics characteristics of male Brazilian junior volleyball players, organised into 3 sports requirement groups: high qualification (HQ) formed by the national team, middle qualification (MQ) formed by athletes playing in the Brazilian national championships and low qualification (LQ) formed by players at school level. 101 athletes were observed, HQ (n=16), MQ (n=68) and LQ (n=17), aged 16.7 ± 0.5; 16.6 ± 0.5 and 16.2 ± 0.7 years, respectively. There following were evaluated: body mass, height, standing reach height, % body fat and Heath & Carter somatotype. The statistical analysis was descriptive and inferential, the Kruskal Wallis test being used for detecting differences between groups (pcharacteristics and requirement levels, considering psports' selection instrument for young talented volleyball players.

  6. The jumping action's indices of female volleyball players and their relation at some somatic characteristics

    Directory of Open Access Journals (Sweden)

    Stech M.

    2010-02-01

    Full Text Available In the paper the results of correlation analysis between of most significance jumping action's indices of high performance polish female volleyball players and their some somatic characteristics (stature, weight and body composition indices: BMI, FATkg, FAT%, FFMkg,FFM%, TBWkg and TBW% are presented. It has been found close correlation between of height of attack jump and stature (r=0,98, weight (r=0,76, FFMkg(r=0,88 and TBWkg (r=0,88. But correlation of height of attack jump with FFM% and TBW% was nonessential. Statistical essential correlation between basic indices of plyometric factor and FAT%, FFM% and TBW% indices (accordingly r = -0,65; 0,65 and 0,66 has been found. The results of the study may be taking into consideration in order to elaboration of effective jumping methods for volleyball players.

  7. CUE USAGE IN VOLLEYBALL: A TIME COURSE COMPARISON OF ELITE, INTERMEDIATE AND NOVICE FEMALE PLAYERS

    Directory of Open Access Journals (Sweden)

    P Vansteenkiste

    2015-01-01

    Full Text Available This study compared visual search strategies in adult female volleyball players of three levels. Video clips of the attack of the opponent team were presented on a large screen and participants reacted to the final pass before the spike. Reaction time, response accuracy and eye movement patterns were measured. Elite players had the highest response accuracy (97.50 ± 3.5% compared to the intermediate (91.50 ± 4.7% and novice players (83.50 ± 17.6%; p<0.05. Novices had a remarkably high range of reaction time but no significant differences were found in comparison to the reaction time of elite and intermediate players. In general, the three groups showed similar gaze behaviour with the apparent use of visual pivots at moments of reception and final pass. This confirms the holistic model of image perception for volleyball and suggests that expert players extract more information from parafoveal regions.

  8. THE EFFECT OF MEDIA LITERACY ON THE SOCIAL IDENTITY OF VOLLEYBALL SPECTATORS THROUGH PERSONAL IDENTITY

    OpenAIRE

    Mahsa Nematzadeh

    2017-01-01

    This research aim was investigating the effect of media literacy on volleyball spectator's social identity through personal identity. The present study, psychologically, is divided in to 8 layers of view paradigm, the main type of applied research: deductive research approaches, quantity research strategies theories, field research tone, cross sectional survey methods, research objectives, description and finally data collection methods, library resource reviews, and questionnaires. The stati...

  9. A COMPARISON OF THE ANTHROPOMETRIC PARAMETERS BETWEEN BASKETBALL PLAYERS, HANDBALL PLAYERS AND VOLLEYBALL PLAYERS

    OpenAIRE

    Florian Miftari; Juel Jarani; Dhimitraq Stratoberdha; Hazir Salihu

    2017-01-01

    The purpose of this study was to compare the anthropometric measurement to the professional players of the three different disciplines of basketball, handball and volleyball. . For each player anthropometric measurements such as weight, body height, waist circumference, BMI and skinfold calculation on different sports are performed. Differences in terms of anthropometric measurements were assessed by independent static tests and the differences for each variable for each sport were evaluated ...

  10. STRUCTURE OF ISOLATED PRECISION FACTORS OF THE MALE STUDENT ON VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Bahri Gjinovci

    2015-06-01

    Full Text Available The aim of this study was to verify the current status of accuracy in volleyball for the students of the faculty of physical education and sports of the University of Prishtina, all the students have successfully passed the exam in volleyball. Also, another aim was to observe whether there are significant statistical differences between both generations of students. In the study were included 70 students (35 from the second academic year and 35 from the fourth academic year. To achieve the aim, were applied standard tests of accuracy in volleyball, such as the following: overhand pass, underhand pass, as well as underhand serve on the six positions and float (tactic serve on three positions. From the basic statistical parameters, it has been noticed that grouping of results from the students of forth academic year are more homogenous, and for this group showed that results are better than at students of first year of studying. While, in the variables is noticed that there are changes into the favour of students of fourth academic year, it has also been noticed that standard deviation is smaller with this group, which shows even more homogenous groups, for example, SFIP group 1 mean 21.65 ±6.48 SD, gr.2 mean 23.68 ±5.76 SD. The obtained results from T-test shows significant statistical changes in both applied tests. The best obtained results are a derivate of continuous professional work, as well as result of “selection”, due to continuous testing and completion of both exams of hand sports and volleyball as an elective subject.

  11. INVESTIGATION THE JOB SATISFACTION LEVELS OF HANDBALL, BASKETBALL AND VOLLEYBALL CLASSIFYING REFEREES

    OpenAIRE

    KARATAŞ, Özgür; SAVUCU, Yüksel; BİÇER, Yonca; YILDIRIM, Eyyup; ÇEVRİM, Hakan

    2013-01-01

    This study was performed to determine the level of job satisfaction (gender, age, marital status, class status, branch, other job, duration of referee, duration of playing the branch, and revenue status) on totally 222 Handball, Basketball and Volleyball referees who working in federation leagues. One-way variance analysis (ANOVA) and LSD test was performed to determine the differences between the groups for the statistical data. Measuring tool has two sections in the study. In the first sect...

  12. Assessment of nutrition, supplementation and body composition parameters on the example of professional volleyball players.

    Science.gov (United States)

    Zapolska, Joanna; Witczak, Katarzyna; Mańczuk, Angelika; Ostrowska, Lucyna

    2014-01-01

    Volleyball is a team game belonging to a group of sports disciplines that involve indirect fighting. Adequate energy coverage in athletes is a crucial issue. It depends primarily on the type, intensity and duration of physical activity related to the sports discipline practiced and to the training cycle duration. The average energy requirement in sportsmen is 50% higher than that of adults. The aim of the study was to characterize the mode of nutrition, including dietary supplements and to assess somatic indices in female volleyball players of the AZS Bialystok team. The study involved 17 women. Research tools included a questionnaire consisting of 24-hour recall, a questionnaire survey concerning supplement intake and body composition analysis performed using a bioimpedance analyzer InBody 220. Data analysis indicates that the anthropometric characteristics and body composition of the AZS Bialystok players meet the recommendations associated with the somatic features in volleyball. Daily diet of the volleyball players were of low-energy with regard to the recommendations for physically active people, with very low supply of carbohydrates and dietary fiber, excessive proportion of saturated fatty acids and dietary cholesterol, and too low content of monounsaturated and polyunsaturated fatty acids. Supply of vitamins and minerals was found to be alarmingly low, especially of iron and calcium; diet supplementation was insufficient. No significant abnormalities were noted in body composition of the study athletes. However, they are recommended to increase muscle mass and slightly reduce body fat. Results of diet evaluation show the need for education in the field of nutrition and the necessity of further research into dietary habits among sportsmen.

  13. Relationships Among Two Repeated Activity Tests and Aerobic Fitness of Volleyball Players.

    Science.gov (United States)

    Meckel, Yoav; May-Rom, Moran; Ekshtien, Aya; Eisenstein, Tamir; Nemet, Dan; Eliakim, Alon

    2015-08-01

    The purpose of the study was to determine performance indices of a repeated sprint test (RST) and to examine their relationships with performance indices of a repeated jump test (RJT) and with aerobic fitness among trained volleyball players. Sixteen male volleyball players performed RST (6 × 30 m sprints), RJT (6 sets of 6 consecutive jumps), and an aerobic power test (20-m Shuttle Run Test). Performance indices for the RST and the RJT were (a) the ideal 30-m run time (IS), the total run time (TS) of the 6 sprints, and the performance decrement (PD) during the test and (b) the ideal jump height (IJ), the total jump height (TJ) of all the jumps, and the PD during the test, respectively. No significant correlations were found between performance indices of the RST and RJT. Significant correlations were found between PD, IS, and TS in the RST protocol and predicted peak V[Combining Dot Above]O2 (r = -0.60, -0.75, -0.77, respectively). No significant correlations were found between performance indices of the RJT (IJ, TJ, and PD) and peak V[Combining Dot Above]O2. The findings suggest that a selection of repeated activity test protocols should acknowledge the specific technique used in the sport, and that a distinct RJT, rather than the classic RST, is more appropriate for assessing the anaerobic capabilities of volleyball players. The findings also suggest that aerobic fitness plays only a minor role in performance maintenance throughout characteristic repeated jumping activity of a volleyball game.

  14. Effects of habitual loading on patellar tendon mechanical and morphological properties in basketball and volleyball players.

    Science.gov (United States)

    Zhang, Z J; Ng, G Y F; Fu, S N

    2015-11-01

    Tendon mechanical properties are linked to sports performance and tendon-related injuries, such as tendinopathy. Whether habitual loading, such as participation in regular jumping activities, would induce adaptation on tendon mechanical properties remains unclear. Forty healthy subjects (10 sedentary, 15 volleyball players, and 15 basketball players) aged between 18 and 35 years were recruited. Supersonic shearwave imaging was used to measure the shear elastic modulus and thickness and cross-sectional area (CSA) of the proximal patellar tendons of both knees at 30° of flexion. Significant group differences in tendon shear elastic modulus were found among the three groups. In the dominant leg, reduction in tendon shear elastic modulus by 18.9 % (p = 0.018) and 48.7 % (p = 0.000) were observed in the basketball and volleyball players, respectively, when compared with sedentary subjects. In the non-dominant leg, reduction in tendon shear elastic modulus were 27.3 % (p = 0.034) and 47.1 % (p = 0.02) in the basketball and volleyball players, respectively. The athlete groups were found to have larger CSA but with similar tendon thickness than sedentary group. The CSA were larger by 24-29 % and by 22-24 % in the basketball players and volleyball players, for the dominant and non-dominant legs, respectively (all p < 0.05). Age and body mass are related to tendon stiffness and CSA, particularly in the sedentary subjects. The proximal patellar tendon can undergo substantial adaptation on tendon mechanical and morphological properties when exposed in jumping sports. Intrinsic factors such as age and body mass could influence tendon properties.

  15. Heart rate variability during pre-competition and competition periods in volleyball players

    OpenAIRE

    Podstawski Robert; Boraczyński Michał; Nowosielska-Swadźba Danuta; Zwolińska Danuta

    2014-01-01

    Study aim: Regular exercise training is thought to modify cardiac autonomic control. One of the body’s responses to training stimuli is heart rate variability (HRV). The use of HRV in the management of sport training is a common practice. The objective of the present study was to assess the impact of the physical activity level on HRV of 1st league national volleyball players prior to and during the competition period.

  16. Heart rate variability during pre-competition and competition periods in volleyball players

    Directory of Open Access Journals (Sweden)

    Podstawski Robert

    2014-01-01

    Full Text Available Study aim: Regular exercise training is thought to modify cardiac autonomic control. One of the body’s responses to training stimuli is heart rate variability (HRV. The use of HRV in the management of sport training is a common practice. The objective of the present study was to assess the impact of the physical activity level on HRV of 1st league national volleyball players prior to and during the competition period.

  17. The positioning of federate sports in Portugal: handball, basketball, roller hockey and volleyball

    OpenAIRE

    Gonçalves, Celina; Correia, Abel

    2005-01-01

    Sport is constituted by a multiplicity of activities with different purposes, concepts and cultural representations. Before the increase of supply, Sports Federations need to understand the practitioners in relation to the several possibilities of practice and to position their sports according to their competitors. In this context, the purpose of this study is the positioning of team federate sports (handball, basketball, roller hockey and volleyball). According to Lindon et al.,...

  18. Rotational Angles and Velocities During Down the Line and Diagonal Across Court Volleyball Spikes

    Directory of Open Access Journals (Sweden)

    Justin R. Brown

    2014-05-01

    Full Text Available The volleyball spike is an explosive movement that is frequently used to end a rally and earn a point. High velocity spikes are an important skill for a successful volleyball offense. Although the influence of vertical jump height and arm velocity on spiked ball velocity (SBV have been investigated, little is known about the relationship of shoulder and hip angular kinematics with SBV. Other sport skills, like the baseball pitch share similar movement patterns and suggest trunk rotation is important for such movements. The purpose of this study was to examine the relationship of both shoulder and hip angular kinematics with ball velocity during the volleyball spike. Methods: Fourteen Division I collegiate female volleyball players executed down the line (DL and diagonally across-court (DAC spikes in a laboratory setting to measure shoulder and hip angular kinematics and velocities. Each spike was analyzed using a 10 Camera Raptor-E Digital Real Time Camera System.  Results: DL SBV was significantly greater than for DAC, respectively (17.54±2.35 vs. 15.97±2.36 m/s, p<0.05.  The Shoulder Hip Separation Angle (S-HSA, Shoulder Angular Velocity (SAV, and Hip Angular Velocity (HAV were all significantly correlated with DAC SBV. S-HSA was the most significant predictor of DAC SBV as determined by regression analysis.  Conclusions: This study provides support for a relationship between a greater S-HSA and SBV. Future research should continue to 1 examine the influence of core training exercise and rotational skill drills on SBV and 2 examine trunk angular velocities during various types of spikes during play.

  19. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    OpenAIRE

    Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

    1995-01-01

    OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and...

  20. The differences in acceleration, maximal speed and agility between soccer, basketball, volleyball and handball players

    OpenAIRE

    Šimonek, Jaromír; Horička, Pavol; Hianik, Ján

    2017-01-01

    Complex reaction speed, acceleration, maximum speed, speed of whole-body change of direction and agility represent the basic components of sport performance mainly in sport games and combat sports. However, contradictory findings have been reported as to the extent of the relationship between the different speed and agility components. This study comprised 117 players (soccer – 56, basketball – 17, volleyball – 20, and handball – 24) playing youth leagues U15-U17 who were assessed for 10-m sp...

  1. Anthropometric and fitness profile of high-level basketball, handball and volleyball players

    OpenAIRE

    J. Peña; D. Moreno-Doutres; J. Coma; M. Cook; B. Buscà

    2018-01-01

    Objective: The aim of this study was to compare several anthropometric and physiological variables between high-level basketball, handball and volleyball players. Method: Forty-six Spanish first division professional players took part in our study. Height, standing reach, body weight, body fat percentages (by using Jackson & Pollock equation), vertical jumps (assessed by Bosco tests), 4 m × 5 m agility test and maximal power output in a bench press exercise were assessed. Results: A one...

  2. Relationships Between Anaerobic Performance, Field Tests and Game Performance of Sitting Volleyball Players

    Directory of Open Access Journals (Sweden)

    Marszalek Jolanta

    2015-12-01

    Full Text Available The aim of this study was to evaluate relationships between anaerobic performance, field tests, game performance and anthropometric variables of sitting volleyball players. Twenty elite Polish sitting volleyball players were tested using the 30 s Wingate Anaerobic Test for arm crank ergometer and participated in six physical field tests. Heights in position to block and to spike, as well as arm reach were measured. Players were observed during the game on the court in terms of effectiveness of the serve, block, attack, receive and defense. Pearson analysis and the Spearman's rank correlation coefficient were used. The strongest correlations were found between the chest pass test and mean power and peak power (r=.846; p=.001 and r=.708; p=.0005, respectively, and also between the T-test and peak power (r= −.718; p=.001. Mean power correlated with the 3 m test (r= −.540; p=.014, the 5 m test (r= −.592; p=.006, and the T-test (r= −.582; p=.007. Peak power correlated with the 3 m test (r= −.632; p=.003, the 5 m test (r= −.613; p=.004, speed & agility (r= −.552; p=.012 and speed & endurance (r=−.546; p=.013. Significant correlations were observed between anthropometric parameters and anaerobic performance variables (p≤.001, and also between anthropometric parameters and field tests (p≤.05. Game performance and physical fitness of sitting volleyball players depended on their anthropometric variables: reach of arms, the position to block and to spike. The chest pass test could be used as a non-laboratory field test of anaerobic performance of sitting volleyball players.

  3. A valid and reliable method to measure jump-specific training and competition load in elite volleyball players.

    Science.gov (United States)

    Skazalski, C; Whiteley, R; Hansen, C; Bahr, R

    2018-05-01

    Use of a commercially available wearable device to monitor jump load with elite volleyball players has become common practice. The purpose of this study was to evaluate the validity and reliability of this device, the Vert, to count jumps and measure jump height with professional volleyball players. Jump count accuracy was determined by comparing jumps recorded by the device to jumps observed through systematic video analysis of three practice sessions and two league matches performed by a men's professional volleyball team. Jumps performed by 14 players were each coded for time and jump type and individually matched to device recorded jumps. Jump height validity of the device was examined against reference standards as participants performed countermovement jumps on a force plate and volleyball-specific jumps with a Vertec. The Vert device accurately counted 99.3% of the 3637 jumps performed during practice and match play. The device showed excellent jump height interdevice reliability for two devices placed in the same pouch during volleyball jumps (r = .99, 95% CI 0.98-0.99). The device had a minimum detectable change (MDC) of 9.7 cm and overestimated jump height by an average of 5.5 cm (95% CI 4.5-6.5) across all volleyball jumps. The Vert device demonstrates excellent accuracy counting volleyball-specific jumps during training and competition. While the device is not recommended to measure maximal jumping ability when precision is needed, it provides an acceptable measure of on-court jump height that can be used to monitor athlete jump load. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Vertical jump performance of professional male and female volleyball players: effects of playing position and competition level.

    Science.gov (United States)

    Sattler, Tine; Hadžić, Vedran; Dervišević, Edvin; Markovic, Goran

    2015-06-01

    Vertical jump (VJ) performance is an important element for successful volleyball practice. The aims of the study were (a) to explore the overall VJ performance of elite volleyball players of both sexes, (b) to explore the differences in VJ performance among different competition levels and different playing positions, and (c) to evaluate the sex-related differences in the role of the arm swing and 3-step approach with arm swing on the jump height. We assessed the VJ capacity in 253 volleyball players (113 males and 140 females) from Slovenian first and second Volleyball Division. The height of squat jump (SJ), countermovement jump, block jump, and attack jump was tested using an Optojump system. We observed significant differences (p ≤ 0.05) in VJ height between different levels of play that were most pronounced in the SJ. Position-related differences in VJ performance were observed in male players between receivers and setters (p ≤ 0.05), whereas in females, VJ performance across different playing positions seems equal. Finally, we found that male players significantly better use the arm swing during VJ than females (p ≤ 0.05), whereas the use of eccentric part of the jump and approach before the spike to improve VJ performance seem to be equally mastered activity in both sexes. These results could assist coaches in the development of jumping performance in volleyball players. Furthermore, presented normative data for jump heights of elite male and female volleyball players could be useful in selection and profiling of young volleyball players.

  5. Design and validation of an observational instrument for technical and tactical actions in beach volleyball

    Directory of Open Access Journals (Sweden)

    José Manuel Palao

    2015-06-01

    Full Text Available Technical and tactical actions determine performance in beach volleyball. This research develops and tests an instrument to monitor and evaluate the manner of execution and efficacy of the actions in beach volleyball. The purpose of this paper was to design and validate an observational instrument to analyze technical and tactical actions in beach volleyball. The instrument collects information regarding: a information about the match (context, b information about game situations, c information about technical situations (serve, reception, set, attack, block, and court defense in relation to player execution, role, manner of execution, execution zone, and efficacy, and d information about the result of the play (win-lose and way point is obtained. Instrument design and validation was done in seven stages: a review of literature and consultation of experts; b pilot observation and data analysis; c expert review of instrument (qualitative and quantitative evaluation; d observer training test; e expert review of instrument (content validity; f measurement of the ability of the instrument to discriminate the result of the set; and g measurement of the ability of the instrument to differentiate between competition age groups. The results show that the instrument allows for obtaining objective and valid information about the players and team from offensive and defensive technical and tactical actions, as well as indirectly from physical actions. The instrument can be used, in its entirety or partially, for researching and coaching purposes.

  6. Loaded and unloaded jump performance of top-level volleyball players from different age categories.

    Science.gov (United States)

    Kitamura, Katia; Pereira, Lucas Adriano; Kobal, Ronaldo; Cal Abad, Cesar Cavinato; Finotti, Ronaldo; Nakamura, Fábio Yuzo; Loturco, Irineu

    2017-09-01

    The aim of this study was to investigate the differences in loaded and unloaded jump performances between different age categories of top-level volleyball players from the same club. Forty-three volleyball players were divided into four age groups: under-17, under-19, under-21 and professional. Vertical jumping height for squat jump (SJ), countermovement jump (CMJ) and CMJ with arm swing (CMJa) and mean propulsive velocity (MPV) in the loaded jump squat exercise with 40% of the athlete's body mass were compared among the different age categories, considering body mass as a covariate. SJ and CMJ jump height values were higher for professional and under-21 players than under-17 players (pjump squat was higher for under-21 players than under-17 players (pjump performances across different age categories of top-level volleyball players. Therefore, to increase the vertical jumping ability of these team sport athletes throughout their long-term development, coaches and strength and conditioning professionals are encouraged to implement consistent neuromuscular training strategies, in accordance with the specific needs and physiological characteristics of each age group.

  7. DIFFERENCES IN FUNCTIONAL AND MOTOR ABILITIES OFYOUNG FOOTBALL PLAYERS, BASKETBALL AND VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Franja Fratrić

    2009-11-01

    Full Text Available The main goal of this research is to determine whether and what differences exist between the three groups of subjects (high-quality football, volleyball and basketball cadets and youth age, in the motoric and functional abilities, as well as to identify dif- ferences between subgroups within each sport. The sample consists of 61 volleyball, 31 basketball player and football player 31 (total n = 123 male, cadet and youth age are members of local clubs. Subjects were born between 01.01.1991 and 12.12.1994. The sample of variables are the values of 17 tests for the evaluation of functional and mobile status. The Motor-functional status on the basis of the results of secondary value of foot- ball, basketball and volleyball make a clear conclusion that the football players showed the best results in almost all the tests and that they had the smallest disbalance in the power of certain groups of muscles.The football players hve the highest homogeneity.

  8. Nonoperative Management and Novel Imaging for Posterior Circumflex Humeral Artery Injury in Volleyball.

    Science.gov (United States)

    van de Pol, Daan; Planken, R Nils; Terpstra, Aart; Pannekoek-Hekman, Marja; Kuijer, P Paul F M; Maas, Mario

    We report on a 34-yr-old male elite volleyball player with symptomatic emboli in the spiking hand from a partially thrombosed aneurysm of the posterior circumflex humeral artery (PCHA) in his dominant shoulder. At initial diagnosis and follow-up, a combination of time-resolved and high-resolution steady state contrast-enhanced magnetic resonance angiography (CE-MRA) enabled detailed visualization of: (1) emboli that were not detectable by vascular ultrasound; and (2) the PCHA aneurysm, including compression during abduction and external rotation (ABER provocation). At 15-month follow-up, including forced cessation of volleyball activities over the preceding 9 months, the PCHA aneurysm remained unchanged. Central filling defects in the palmar arch and digital arteries resolved over time and affected arterial vessel segments showed postthrombotic changes. Digital blood pressure values improved substantially and almost normalized during follow-up. In conclusion, this case report is the first to show promising results of nonoperative management for a vascular shoulder overuse injury in a professional volleyball player as an alternative to invasive therapeutic options.

  9. Ultrasonographic evaluation of the shoulder in elite Italian beach volleyball players.

    Science.gov (United States)

    Monteleone, G; Tramontana, A; Mc Donald, K; Sorge, R; Tiloca, A; Foti, C

    2015-10-01

    Beach volleyball is an overhead sport that subjects the hitting shoulder to intense functional loads. The purpose of this study is to identify ultrasonographically the prevalence of myotendinous alterations in professional Italian beach volleyball players at the Italian championship and to look for associations between ultrasound findings and the other data collected. Fifty-three beach volleyball players (31 women, 22 men) were recruited during the second stage of the Italian championship held in July 2012 in Rome, Italy. Clinical history was obtained from all subjects, followed by physical exam. Each athlete completed a questionnaire regarding sports activities. Bilateral ultrasonographic evaluation of the shoulders was then performed. Calcific tendinopathy of the rotator cuff of the hitting shoulder was identified ultrasonographically in 30% of the athletes. The mean age of the athletes with calcific tendinopathy was older than subjects with other abnormalities on ultrasonographic examination (33.1 years vs. 25.8 years, t-test; Pvolleyball players has a prevalence of 30% ultrasonographically, greater than that reported in the general population. In these athletes, the presence of calcific tendinopathy correlates positively with age.

  10. Shoulder-Rotator Strength, Range of Motion, and Acromiohumeral Distance in Asymptomatic Adolescent Volleyball Attackers.

    Science.gov (United States)

    Harput, Gulcan; Guney, Hande; Toprak, Ugur; Kaya, Tunca; Colakoglu, Fatma Filiz; Baltaci, Gul

    2016-09-01

    Sport-specific adaptations at the glenohumeral joint could occur in adolescent athletes because they start participating in high-performance sports in early childhood. To investigate shoulder-rotator strength, internal-rotation (IR) and external-rotation (ER) range of motion (ROM), and acromiohumeral distance (AHD) in asymptomatic adolescent volleyball attackers to determine if they have risk factors for injury. Cross-sectional study. University laboratory. Thirty-nine adolescent high school-aged volleyball attackers (22 boys, 17 girls; age = 16.0 ± 1.4 years, height = 179.2 ± 9.0 cm, mass = 67.1 ± 10.9 kg, body mass index = 20.7 ± 2.6 kg/m 2 ). Shoulder IR and ER ROM, total-rotation ROM, glenohumeral IR deficit, AHD, and concentric and eccentric strength of the shoulder internal and external rotators were tested bilaterally. External-rotation ROM was greater (t 38 = 4.92, P 18°). We observed greater concentric internal-rotator (t 38 = 2.89, P = .006) and eccentric external-rotator (t 38 = 2.65, P = .01) strength in the dominant than in the nondominant shoulder. The AHD was less in the dominant shoulder (t 38 = -3.60, P volleyball attackers demonstrated decreased IR ROM, total ROM, and AHD and increased ER ROM in their dominant shoulder. Therefore, routine screening of adolescent athletes and designing training programs for hazardous adaptive changes could be important in preventing shoulder injuries.

  11. SPECIFIC SITES OF BONE EXPANSION DEPEND ON THE LEVEL OF VOLLEYBALL PRACTICE IN PREPUBESCENT BOYS

    Directory of Open Access Journals (Sweden)

    Hamada Chaari

    2013-06-01

    Full Text Available The purpose of this study was to investigate the effect of 18 months of high and low levels of volleyball practice on bone acquisition. 130 prepubescent boys (mean age 11.4 ± 0.7 were divided into a high-level training group (HLG, low-level training group (LLG, and controls. Bone mineral content (BMC and bone area at the whole body, lumbar spine L2-L4, femoral neck of the dominant leg, and right and left radius were measured using dual-photon X-ray absorptiometry. Enhanced BMC resulted from high-training volleyball activity in all measured sites except the third left and right distal radius, which is not modified by low-level training in prepubescent players but it was accompanied by a bone area expansion in radius and weight-bearing sites for the HLG, and in legs, whole right and left radius for the LLG. Significant improvement of skeletal tissues is associated with the intensity and duration of volleyball training.

  12. Which skills and factors better predict winning and losing in high-level men's volleyball?

    Science.gov (United States)

    Peña, Javier; Rodríguez-Guerra, Jorge; Buscà, Bernat; Serra, Núria

    2013-09-01

    The aim of this study was to determine which skills and factors better predicted the outcomes of regular season volleyball matches in the Spanish "Superliga" and were significant for obtaining positive results in the game. The study sample consisted of 125 matches played during the 2010-11 Spanish men's first division volleyball championship. Matches were played by 12 teams composed of 148 players from 17 different nations from October 2010 to March 2011. The variables analyzed were the result of the game, team category, home/away court factors, points obtained in the break point phase, number of service errors, number of service aces, number of reception errors, percentage of positive receptions, percentage of perfect receptions, reception efficiency, number of attack errors, number of blocked attacks, attack points, percentage of attack points, attack efficiency, and number of blocks performed by both teams participating in the match. The results showed that the variables of team category, points obtained in the break point phase, number of reception errors, and number of blocked attacks by the opponent were significant predictors of winning or losing the matches. Odds ratios indicated that the odds of winning a volleyball match were 6.7 times greater for the teams belonging to higher rankings and that every additional point in Complex II increased the odds of winning a match by 1.5 times. Every reception and blocked ball error decreased the possibility of winning by 0.6 and 0.7 times, respectively.

  13. Foveal and peripheral fields of vision influences perceptual skill in anticipating opponents' attacking position in volleyball.

    Science.gov (United States)

    Schorer, Jörg; Rienhoff, Rebecca; Fischer, Lennart; Baker, Joseph

    2013-09-01

    The importance of perceptual-cognitive expertise in sport has been repeatedly demonstrated. In this study we examined the role of different sources of visual information (i.e., foveal versus peripheral) in anticipating volleyball attack positions. Expert (n = 11), advanced (n = 13) and novice (n = 16) players completed an anticipation task that involved predicting the location of volleyball attacks. Video clips of volleyball attacks (n = 72) were spatially and temporally occluded to provide varying amounts of information to the participant. In addition, participants viewed the attacks under three visual conditions: full vision, foveal vision only, and peripheral vision only. Analysis of variance revealed significant between group differences in prediction accuracy with higher skilled players performing better than lower skilled players. Additionally, we found significant differences between temporal and spatial occlusion conditions. Both of those factors interacted separately, but not combined with expertise. Importantly, for experts the sum of both fields of vision was superior to either source in isolation. Our results suggest different sources of visual information work collectively to facilitate expert anticipation in time-constrained sports and reinforce the complexity of expert perception.

  14. Correspondence between training load executed by volleyball players and the one observed by coaches.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Medina, Javier; García-López, Juan; García-Tormo, José V; Foster, Carl

    2014-06-01

    The main aim of this study was to compare the training load (TL) executed by volleyball players with that observed by coaches. Second, we analyzed the influence of the coaches' experience in the estimated TL. Twelve female volleyball players and 4 male coaches participated in this study. During a period of 15 weeks, physical (PT) and technical-tactical training sessions and matches were monitored. In each session, the session rating of perceived exertion (sRPE) was recorded to analyze the players' exercise intensity and TL(RP)E. Coaches were present in all sessions and rated their estimate of sRPE at the same time as the players to calculate the coaches' TL(RPE). Both players' and coaches' mean sRPE (4.0 ± 1.1, 3.7 ± 1.1, and 3.8 ± 1.0 in players and expert and beginning coaches, respectively) and TLRPE (380.1 ± 106.8, 358.3 ± 110.5, and 359.7 ± 108.0 in players and expert and beginning coaches, respectively) were similar. However, a higher (p volleyball.

  15. Characteristics and contributing factors related to sports injuries in young volleyball players

    Science.gov (United States)

    2013-01-01

    Background The participation of young in volleyball is becoming increasingly common, and this increased involvement raises concerns about the risk of installation of sports injuries. Therefore, the objectives the study were identify the characteristics of sports injuries in young volleyball players and associate anthropometric and training variables with contributing factors for injuries. Methods A total of 522 volleyball players participating in the High School Olympic Games of the State of São Paulo (Brazil) were interviewed. A reported condition inquiry was used to gather information on injuries, such as anatomic site affected, mechanism and moment of injury, as well as personal and training data. The level of significance was set at 5%. Results A 19% frequency of injuries was found. Higher age, weight, height, body mass index and training duration values were associated with the occurrence of injuries. The most affected anatomic site was the ankle/foot complex (45 injuries, 36.3%). Direct contact and contactless mechanisms were the main causes of injuries (61 injuries; 49.2% and 48 injuries; 38.7%, respectively). Training was the moment in which most injuries occurred (93 injuries; 75%), independently of personal and training characteristics. Conclusion Injuries affected the ankle/foot complex with a greater frequency. Direct contact and contactless mechanisms were the most frequently reported and injuries occurred mainly during training sessions. Personal and training characteristics were contributing factors for the occurrence of injuries. PMID:24124803

  16. EFFECTS OF PLYOMETRIC TRAINING ON THE DEVELOPMENT THE VERTICAL JUMP IN VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Soundara rajan R

    2010-08-01

    Full Text Available Abstract:The present study investigated the effect of plyometric training on development of the vertical jump of volleyball players. The study consisted of 30 male volleyball players from PSG College of Arts & Science, Coimbatore, their age ranged from 18 to 25 years. Participants articipants were randomly assigned Group I underwent plyometric training group and Group II control group. The plyometric training group carried out a set of plyometric exercises also designed by the researcher twice a week for six weeks. The control group was allowed to play their game, but they were not given any treatments. For the purpose of this research, two tests forthe evaluation of the volleyball vertical jump were validated: the block jump and spike jump. The data was analysed using Paired t-tests which were used to test the effect of treatment groups individually between pre and post –tests, of all the groups, on variables used in the present study. The analysis of covariance was used toanalsze the collected data. The result of the study reveals that there was significant difference in 0.05 levels.Based on the findings of the research and the discussion, one could conclude that the exercise model for the development of the vertical jump that had been used, as the fundamental factor of the experimental group, has contributed to the statistically significant difference in the increase of the vertical jump in comparison to thecontrol group, which had used technically tactical contents to develop the vertical jump.

  17. Variables that Predict Serve Efficacy in Elite Men's Volleyball with Different Quality of Opposition Sets.

    Science.gov (United States)

    Valhondo, Álvaro; Fernández-Echeverría, Carmen; González-Silva, Jara; Claver, Fernando; Moreno, M Perla

    2018-03-01

    The objective of this study was to determine the variables that predicted serve efficacy in elite men's volleyball, in sets with different quality of opposition. 3292 serve actions were analysed, of which 2254 were carried out in high quality of opposition sets and 1038 actions were in low quality of opposition sets, corresponding to a total of 24 matches played during the Men's European Volleyball Championships held in 2011. The independent variables considered in this study were the serve zone, serve type, serving player, serve direction, reception zone, receiving player and reception type; the dependent variable was serve efficacy and the situational variable was quality of opposition sets. The variables that acted as predictors in both high and low quality of opposition sets were the serving player, reception zone and reception type. The serve type variable only acted as a predictor in high quality of opposition sets, while the serve zone variable only acted as a predictor in low quality of opposition sets. These results may provide important guidance in men's volleyball training processes.

  18. Effect of an Arm Swing on Countermovement Vertical Jump Performance in Elite Volleyball Players

    Directory of Open Access Journals (Sweden)

    Vaverka Frantisek

    2016-12-01

    Full Text Available The aim of this study was to determine how elite volleyball players employed the arm swing (AS to enhance their jump performance. The study assessed how the AS influenced the duration and magnitude of the vertical ground reaction force (VGRF during the main phases (preparatory, braking and accelerating of the countermovement vertical jump (CMVJ, the starting position of the body at the beginning of the accelerating phase and the moment when the AS began contributing to increasing the jump height. Eighteen elite volleyball players performed three CMVJs with and without an AS. Kinetics and kinematics data were collected using two Kistler force plates and the C-motion system. The time and force variables were evaluated based on the VGRF, and the position of the body and the trajectory of the arm movement were determined using kinematic analysis. The AS improved the CMVJ by increasing the jump height by 38% relative to jumping without an AS. The AS significantly shortened the braking phase and prolonged the accelerating phase, however, it did not influence the preparatory phase or the overall jump duration. The AS also significantly increased the average force during the accelerating phase as well as the accelerating impulse. The AS upward began at 76% into the overall jump duration. The AS did not influence the body position at the beginning of the accelerating phase. These findings can be used to improve performance of the CMVJ with the AS and in teaching beginning volleyball players proper jumping technique.

  19. The Effects of Core Stability Exercise on the Dynamic Balance of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Hassan Sadeghi

    2013-12-01

    Full Text Available Dynamic balance is a key component of injury prevention and rehabilitation in sports. Training the core muscles has been hypothesized as an intervention for improving balance. However, there is a lack of current scientific evidence to support this claim. The purpose of this study was to evaluate the effects of a core stability program on dynamic balance of volleyball players as measured with the Star Excursion Balance Test (SEBT. Thirty healthy participants were divided into 2 groups: control and exercise groups. All participants performed the SEBT before and after 8-week exercise time. During the 8-week time, the exercise group performed a core stability program, whereas the control group abstained from any new exercise. These results also illustrated there was significant differences in the scores for pre-test and post-test of all direction according SEBT in the experimental group. An independent sample t-test was conducted to compare experimental and control group (F=43.573, Sig=0.000. These results were a significant difference in the scores for control and experimental groups. Maximum excursion distances improved for the exercise group, compared with the control group. This result justifies the hypothesis that core strengthening can improve dynamic postural control during landing of volleyball players significantly. Keywords: Core stabilization; volleyball player; dynamic balance; SEBT

  20. Game-Related Performance Factors in four European Men's Professional Volleyball Championships.

    Science.gov (United States)

    Peña, Javier; Casals, Martí

    2016-12-01

    The present study was designed to assess the relevance of game-related performance factors as outcome predictors in high-level volleyball. To carry out the analysis, the official box scores of 399 matches played by 47 different teams in four different European male professional volleyball leagues (Italy, Poland, Germany and Turkey) during the 2013-14 regular season were analyzed. A logistic mixed model was performed to determine the effects of different variables in matches' outcomes. According to the multivariate analysis the following factors were significantly associated with winning matches: the number of scorers (OR = 1.32; CI: 1.09 - 1.59), service errors (OR = 0.91; CI: 0.87 - 0.95), service points (OR = 1.25; CI: 1.15 -1.36), reception errors (OR = 0.79; CI: 0.74 - 0.84), the percentage of positive receptions (OR = 1.02; CI: 1.00 -1.04) and blocked balls (OR = 1.17; CI: 1.11 - 1.26). Team category 2 (OR = 0.39; CI: 0.24 - 0.63) and team category 3 (OR = 0.15; CI: 0.09 - 0.25) were significantly associated with losing matches. These findings can contribute to a better understanding of performance indicators in professional volleyball, helping coaches and decision makers to better determine the importance of particular game factors.

  1. Game-Related Performance Factors in four European Men’s Professional Volleyball Championships

    Directory of Open Access Journals (Sweden)

    Peña Javier

    2016-12-01

    Full Text Available The present study was designed to assess the relevance of game-related performance factors as outcome predictors in high-level volleyball. To carry out the analysis, the official box scores of 399 matches played by 47 different teams in four different European male professional volleyball leagues (Italy, Poland, Germany and Turkey during the 2013-14 regular season were analyzed. A logistic mixed model was performed to determine the effects of different variables in matches’ outcomes. According to the multivariate analysis the following factors were significantly associated with winning matches: the number of scorers (OR = 1.32; CI: 1.09 – 1.59, service errors (OR = 0.91; CI: 0.87 – 0.95, service points (OR = 1.25; CI: 1.15 -1.36, reception errors (OR = 0.79; CI: 0.74 – 0.84, the percentage of positive receptions (OR = 1.02; CI: 1.00 -1.04 and blocked balls (OR = 1.17; CI: 1.11 – 1.26. Team category 2 (OR = 0.39; CI: 0.24 – 0.63 and team category 3 (OR = 0.15; CI: 0.09 – 0.25 were significantly associated with losing matches. These findings can contribute to a better understanding of performance indicators in professional volleyball, helping coaches and decision makers to better determine the importance of particular game factors.

  2. Characteristics and contributing factors related to sports injuries in young volleyball players.

    Science.gov (United States)

    Vanderlei, Franciele Marques; Bastos, Fabio Nascimento; Tsutsumi, Gustavo Yuki Cantalejo; Vanderlei, Luiz Carlos Marques; Netto Júnior, Jayme; Pastre, Carlos Marcelo

    2013-10-14

    The participation of young in volleyball is becoming increasingly common, and this increased involvement raises concerns about the risk of installation of sports injuries. Therefore, the objectives the study were identify the characteristics of sports injuries in young volleyball players and associate anthropometric and training variables with contributing factors for injuries. A total of 522 volleyball players participating in the High School Olympic Games of the State of São Paulo (Brazil) were interviewed. A reported condition inquiry was used to gather information on injuries, such as anatomic site affected, mechanism and moment of injury, as well as personal and training data. The level of significance was set at 5%. A 19% frequency of injuries was found. Higher age, weight, height, body mass index and training duration values were associated with the occurrence of injuries. The most affected anatomic site was the ankle/foot complex (45 injuries, 36.3%). Direct contact and contactless mechanisms were the main causes of injuries (61 injuries; 49.2% and 48 injuries; 38.7%, respectively). Training was the moment in which most injuries occurred (93 injuries; 75%), independently of personal and training characteristics. Injuries affected the ankle/foot complex with a greater frequency. Direct contact and contactless mechanisms were the most frequently reported and injuries occurred mainly during training sessions. Personal and training characteristics were contributing factors for the occurrence of injuries.

  3. Frac Sand Mines Are Preferentially Sited in Unzoned Rural Areas.

    Directory of Open Access Journals (Sweden)

    Christina Locke

    Full Text Available Shifting markets can cause unexpected, stochastic changes in rural landscapes that may take local communities by surprise. Preferential siting of new industrial facilities in poor areas or in areas with few regulatory restrictions can have implications for environmental sustainability, human health, and social justice. This study focuses on frac sand mining-the mining of high-quality silica sand used in hydraulic fracturing processes for gas and oil extraction. Frac sand mining gained prominence in the 2000s in the upper midwestern United States where nonmetallic mining is regulated primarily by local zoning. I asked whether frac sand mines were more commonly sited in rural townships without formal zoning regulations or planning processes than in those that undertook zoning and planning before the frac sand boom. I also asked if mine prevalence was correlated with socioeconomic differences across townships. After creating a probability surface to map areas most suitable for frac sand mine occurrence, I developed neutral landscape models from which to compare actual mine distributions in zoned and unzoned areas at three different spatial extents. Mines were significantly clustered in unzoned jurisdictions at the statewide level and in 7 of the 8 counties with at least three frac sand mines and some unzoned land. Subsequent regression analyses showed mine prevalence to be uncorrelated with land value, tax rate, or per capita income, but correlated with remoteness and zoning. The predicted mine count in unzoned townships was over two times higher than that in zoned townships. However, the county with the most mines by far was under a county zoning ordinance, perhaps indicating industry preferences for locations with clear, homogenous rules over patchwork regulation. Rural communities can use the case of frac sand mining as motivation to discuss and plan for sudden land-use predicaments, rather than wait to grapple with unfamiliar legal processes

  4. Frac Sand Mines Are Preferentially Sited in Unzoned Rural Areas.

    Science.gov (United States)

    Locke, Christina

    2015-01-01

    Shifting markets can cause unexpected, stochastic changes in rural landscapes that may take local communities by surprise. Preferential siting of new industrial facilities in poor areas or in areas with few regulatory restrictions can have implications for environmental sustainability, human health, and social justice. This study focuses on frac sand mining-the mining of high-quality silica sand used in hydraulic fracturing processes for gas and oil extraction. Frac sand mining gained prominence in the 2000s in the upper midwestern United States where nonmetallic mining is regulated primarily by local zoning. I asked whether frac sand mines were more commonly sited in rural townships without formal zoning regulations or planning processes than in those that undertook zoning and planning before the frac sand boom. I also asked if mine prevalence was correlated with socioeconomic differences across townships. After creating a probability surface to map areas most suitable for frac sand mine occurrence, I developed neutral landscape models from which to compare actual mine distributions in zoned and unzoned areas at three different spatial extents. Mines were significantly clustered in unzoned jurisdictions at the statewide level and in 7 of the 8 counties with at least three frac sand mines and some unzoned land. Subsequent regression analyses showed mine prevalence to be uncorrelated with land value, tax rate, or per capita income, but correlated with remoteness and zoning. The predicted mine count in unzoned townships was over two times higher than that in zoned townships. However, the county with the most mines by far was under a county zoning ordinance, perhaps indicating industry preferences for locations with clear, homogenous rules over patchwork regulation. Rural communities can use the case of frac sand mining as motivation to discuss and plan for sudden land-use predicaments, rather than wait to grapple with unfamiliar legal processes during a period of

  5. Rheological Characterization of Green Sand Flow

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

    2016-01-01

    The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantif...

  6. User Survey of 3 Ankle Braces in Soccer, Volleyball, and Running: Which Brace Fits Best?

    Science.gov (United States)

    Janssen, Kasper; Van Den Berg, Anjulie; Van Mechelen, Willem; Verhagen, Evert

    2017-08-01

      Recurrence rates for ankle sprains are high. Therefore, preventive measures such as ankle bracing during sports are recommended.   To systematically evaluate the perceived ease of use, quality, comfort, stability, and hindrance of and the overall satisfaction with 3 contemporary brace types in 3 types of sports.   Randomized comparative user survey.   Recreational sports: soccer, volleyball, and running.   Young adult recreational athletes (29 soccer players, 26 volleyball players, and 31 runners).   Compression brace (CB), lace-up brace (LB), and semirigid brace (SB).   Rating of perceived ease of use, quality, comfort, stability, and hindrance of and overall satisfaction with the brace types during sports on a 5-point Likert scale. The secondary outcome measure was participants' willingness to buy the tested brace.   Overall, the 3 brace types received high mean scores for ease of use and quality. Soccer players preferred the CB over both alternatives, considering the higher scores for comfort (CB = 4.0, LB = 3.5, SB = 2.8), hindrance (CB = 3.7, LB = 2.9, SB = 2.8), overall satisfaction (CB = 3.6, LB = 3.0, SB = 2.5), and greatest willingness to buy this brace. Volleyball players preferred the LB over both alternatives, considering the higher scores for stability (LB = 4.2, CB = 3.2, SB = 3.3), overall satisfaction (LB = 3.8, CB = 3.0, SB = 3.0), and greatest willingness to buy this brace. Runners preferred the CB over both alternatives considering the better score for hindrance (CB = 3.6, LB = 2.8, SB = 2.9) and greatest willingness to buy this brace.   All 3 ankle-brace types scored high on perceived ease of use and quality. Regarding the brace types, soccer players, volleyball players, and runners differed in their assessments of subjective evaluation of comfort, stability, hindrance, overall satisfaction, and willingness to buy the brace. Soccer players and runners preferred the CB, whereas volleyball players preferred the LB.

  7. Vertical Jumping Tests versus Wingate Anaerobic Test in Female Volleyball Players: The Role of Age

    Directory of Open Access Journals (Sweden)

    Pantelis Theodoros Nikolaidis

    2016-02-01

    Full Text Available Single and continuous vertical jumping tests, as well as the Wingate anaerobic test (WAnT, are commonly used to assess the short-term muscle power of female volleyball players; however, the relationship among these tests has not been studied adequately. Thus, the aim of the present study was to examine the relationship of single and continuous vertical jumps with the WAnT in female volleyball players. Seventy adolescent (age 16.0 ± 1.0 years, body mass 62.5 ± 7.1 kg, height 170.4 ± 6.1 cm, body fat 24.2% ± 4.3% and 108 adult female volleyball players (age 24.8 ± 5.2 years, body mass 66.5 ± 8.7 kg, height 173.2 ± 7.4 cm, body fat 22.0% ± 5.1% performed the squat jump (SJ, countermovement jump (CMJ, Abalakov jump (AJ, 30 s Bosco test and WAnT (peak power, Ppeak; mean power, Pmean. Mean power in the Bosco test was correlated (low to large magnitude with Pmean of the WAnT (r = 0.27, p = 0.030 in adolescents versus r = 0.56, p < 0.001 in adults. SJ, CMJ and AJ also correlated with Ppeak (0.28 ≤ r ≤ 0.46 in adolescents versus 0.58 ≤ r ≤ 0.61 in adults and with Pmean (0.43 ≤ r ≤ 0.51 versus 0.67 ≤ r ≤ 0.71, respectively of the WAnT (p < 0.05. In summary, the impact of the Bosco test and WAnT on muscle power varied, especially in the younger age group. Single jumping tests had larger correlations with WAnT in adults than in adolescent volleyball players. These findings should be taken into account by volleyball coaches and fitness trainers during the assessment of short-term muscle power of their athletes.

  8. The effects of 6 weeks of preseason skill-based conditioning on physical performance in male volleyball players.

    Science.gov (United States)

    Trajković, Nebojša; Milanović, Zoran; Sporis, Goran; Milić, Vladan; Stanković, Ratko

    2012-06-01

    The purpose of this study was to determine the changes in physical performance after a 6-week skill-based conditioning training program in male competitive volleyball players. Sixteen male volleyball players (mean ± SD: age 22.3 ± 3.7 years, body height 190.7 ± 4.2 cm, and body mass 78.4 ± 4.5 kg) participated in this study. The players were tested for sprinting (5- and 10-m sprint), agility, and jumping performance (the vertical-jump test, the spike-jump test, and the standing broad jump [SBJ]). Compared with pretraining, there was a significant improvement in the 5- and 10-m speed. There were no significant differences between pretraining and posttraining for lower-body muscular power (vertical-jump height, spike-jump height, and SBJ) and agility. Based on our results, it could be concluded that a preseason skill-based conditioning program does not offer a sufficient stimulus for volleyball players. Therefore, a general conditioning and hypertrophy training along with specific volleyball conditioning is necessary in the preseason period for the development of the lower-body strength, agility and speed performance in volleyball players.

  9. Sand, jams and jets

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, H. [James Franck Institute and Department of Physics, University of Chicago (United States)]. E-mail: h-jaeger@uchicago.edu

    2005-12-01

    Granular media are offering new insights into problems in condensed-matter physics and materials science, as Heinrich Jaeger explains. The remarkable properties of granular materials are so familiar that most of us do not even notice them. It is clear, for example, that we cannot walk on water unless the temperature has dropped below freezing. However, we take it for granted that sand will support our weight as if it were a solid, even though it can also be poured like a liquid under the same ambient conditions. From breakfast cereal, sugar and flour to construction materials, mining products and pharmaceuticals, granular media are present everywhere in our daily lives. (U.K.)

  10. Riddle of the sands

    Energy Technology Data Exchange (ETDEWEB)

    Rolheiser, P

    1998-09-01

    A geological model of the Alberta landscape during the period stretching from about 110 million to 100 million years ago during the Cretaceous period when dinosaurs roamed the earth, was sketched. Today, the region contains the Cold Lake oil sands deposit. Imperial Oil began large-scale production at Cold Lake in 1985. The formations within the area are the source of almost half of Imperial Oil`s daily crude oil production and account for one in every 20 barrels of oil produced daily in Canada. The bitumen is produced using cyclic steam stimulation where steam is injected at high pressure into the underground reservoir, fracturing the sandstone and heating the bitumen it holds to thin it so that it can then flow through well bores to the surface. Conventional geological theory suggested that the Cold Lake reservoir was the remains of a prehistoric river delta. In 1994, Imperial Oil established a Cold Lake sequence stratigraphy project to verify this theory. This highly complex project involves volumes of geophysical well-log data from the 2,500 wells at Cold Lake, core samples cut from more than 600 of these wells and microscopic fossilized remains of 100-million-year-old flora extracted from the core samples, and seismic information. The interpreted data helps to create a three-dimensional model of the reservoir`s structure and help define its boundaries. Results have shown that the Cold Lake deposit was created from at least 13 intersecting river beds. Each of the rivers flowed for a few hundred thousand years and deposited sands of varying quality in different layers and patterns. The oil came about 40 million years later after the plant and animal materials containing hydrogen and carbon were broken down by heat and pressure to form oil. 1 fig.

  11. The Alberta oil sands story

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    This report serves as a detailed introduction to the Alberta oil sands and their development. It includes a description of the oil sands deposits, an outline of crude bitumen recovery and upgrading processes, the role of Alberta Energy Company in oil sands development, environmental aspects, manpower requirements for oil sands development, research needs, and further oil sands projects. Presently proven recoverable reserves in the oil sands amount to 26.5 billion bbl of synthetic crude. Production from the Syncrude plant (125,000 bbl/d capacity) is expected to begin in 1977, followed by a Shell Canada operation around 1980. The provincial government will participate in the oil sand industry through its joint venture participation in Syncrude and its 50% share in Alberta Energy Company; the latter company participates in related aspects of the Syncrude project, such as pipelines. The result of Alberta's participation in the industry will mean that, directly or indirectly, the province will realize 60% of the total profits. The job creation potential of oil sands projects is estimated to be extensive, with a direct and indirect work force supported by oil sands activities possibly reaching 180,000 persons by the year 2000. Research needs have been identified, particularly in the area of in-situ thermal recovery technology, and the creation of the Alberta Oil Sands Technology and Research Authority has been authorized in order to meet these needs. Although current reserves are sufficient to support 20-30 synthetic crude plants, a number of factors will limit expansion of the industry. 8 figs., 5 tabs.

  12. The methodological basis for determining individual characteristics of volleyball players at the stage of basic training specialist.

    Directory of Open Access Journals (Sweden)

    Kozina Zh.L.

    2012-03-01

    Full Text Available Purpose of work - to form and methodologically ground conception of individualization of training process in the playing types of sport. The algorithm of determination of individual features is presented in the structure of preparedness of skilled volley-ballers. In research 20 volley-ballers took part on the stage of the specialized base preparation. The stages of determination of command and individual factor structure of preparedness of sportswomen are presented. It is exposed that individual descriptions of volley-ballers and their line of business not always are related exceptionally to anthropometric information. Descriptions also depend and from the row of other physiological and психофизиологических indexes. These indexes for certain differentiate for the players of different line of role.

  13. A Comparison of Women's Collegiate and Girls' High School Volleyball Injury Data Collected Prospectively Over a 4-Year Period.

    Science.gov (United States)

    Reeser, Jonathan C; Gregory, Andrew; Berg, Richard L; Comstock, R Dawn

    2015-01-01

    There is a relative paucity of research examining the sport-specific injury epidemiology of high school and collegiate volleyball athletes. Moreover, differences in study methodology frequently limit our ability to compare and contrast injury data collected from selected populations. There are differences between the injury patterns characteristic of high school and collegiate female volleyball athletes. Retrospective clinical review. Level 3. We statistically analyzed injury incidence and outcome data collected over a 4-year interval (2005-2006 to 2008-2009) by 2 similar injury surveillance systems, the National Collegiate Athletic Association's Injury Surveillance System (NCAA ISS) and the High School Reporting Injuries Online (HS RIO). We compared diagnoses, anatomic distribution of injuries, mechanisms of injury, and time lost from training or competition between high school and collegiate volleyball athletes. The overall volleyball-related injury rate was significantly greater among collegiate athletes than among high school athletes during both competition (injury rate ratio, 2.9; 95% CI, 2.5-3.4) and practice (injury rate ratio, 3.5; 95% CI, 3.1-3.9). Collegiate athletes had a higher rate of ankle sprain, knee injury, and shoulder injury. Concussions represented a relatively high percentage of injuries in both populations (5.0% of total NCAA ISS injuries vs 4.8% of total HS RIO injuries, respectively). The data suggest that although similar, there were distinct differences between the injury patterns of the 2 populations. Compared with high school volleyball players, collegiate athletes have a higher rate of acute time loss injury as well as overuse time loss injury (particularly patellar tendinosis). Concussions represented a significant and worrisome component of the injury pattern for both study populations. The injury data suggest that important differences exist in the injury patterns of female high school compared with collegiate volleyball athletes

  14. Direct Chlorination of Zircon Sand

    International Nuclear Information System (INIS)

    Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

    2002-01-01

    It was investigated the direct chlorination of zircon sand in a unit chlorination equipment. The process was in semi batch. The product gas was scrubbed in aqueous NaOH. It was search the influence of time, ratio of reactant and size of particle sand to the concentration of Zr and Si in the product. From these research it was found that as the times, ratio of reactant increased, the concentration of Zr increased, but the concentration of Si decreased, while as grain size of zircon sand decreased the concentration of Zr decreased, but the concentration of Si increased. (author)

  15. Oil sands and the environment

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

    2004-07-01

    Oil sands are a significant resource for Alberta and Canada with continuing growth opportunity. There is a need to ensure sustainable development of the oil sands resources from a social, economic and environmental perspective. The industry has succeeded in terms of proven reserves, technology advancements, reduced operating costs, reliability and market accessibility. Some of the major challenges facing the industry include high capital cost, infrastructure, social services and keeping pace with growth. This presentation outlined the proactive measures that the oil sands industry has taken to manage environmental issues such as sulphur dioxide and nitrogen oxide emissions, greenhouse gases, water management and land reclamation. tabs., figs.

  16. QUANTITATIVE AND QUALITATIVE DIFFERENCES OF MORPHOLOGICAL CHARACTERISTICS AND EXPLOSIVE STRENGTH OF LEGS IN UNDER-16 FEMALE AND MALE VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Slobodan Andrašić

    2015-05-01

    Full Text Available In order to achieve an advantage over the opponent, all the game elements, for which it is possible, are tended to be performed by jumping (Ziv & Lidor, 2010. This is supported by the fact that research of vertical jumping ability of volleyball players of different levels, found that players at a higher level of competition also achieve better results on tests of the assessment of vertical jumping ability (Forthomme, Croisier, Ciccarone, Crielaard, & Cloes, 2005. The research subject was aimed at detecting the difference between male and female volleyball players in morphological characteristics and explosive strength of legs, as well as determining the size of the impact of morphological characteristics of the explosive power of the lower limbs between groups formed on the basis of gender dimorphism. Method: The sample in this study was derived from a population of volleyball players of OK “RFU” from Futog, N=27 and female volleyball players of ŽOK “Futog” from Futog, N=38. For the purposes of this research morphological characteristics were measured. By using MANOVA and ANOVA differences were determined between the two sub-samples of respondents formed on the basis of gender dimorphism regarding the analyzed morphological and motor variables. In order to determine effects of the system of predictor variables on the criteria variables we used Linear Regression Analysis. Results: Statistically significant differences were observed for the variables Body height, Legs length and Lower-leg circumference, as well as for all three motor variables: Spike jump, Standing triple jump and Standing vertical jump in favor of volleyball players. Linear Regression Analysis revealed the impact of the predictor system of morphological characteristics on the criterion Spike jump in both subsamples. It was found that Body height gives the highest contribution to achieving better results regarding the height reached during spike jump in both groups

  17. Saltation of non-spherical sand particles.

    Directory of Open Access Journals (Sweden)

    Zhengshi Wang

    Full Text Available Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement.

  18. Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2011-04-01

    Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

  19. Effect Of Plyometric Training On Vertical Jump Performance And Neuromuscular Adaptation In Volleyball Player

    Directory of Open Access Journals (Sweden)

    Dara Hosseini

    2012-12-01

    Full Text Available The purpose of this study was to examine the effectiveness of 12-week plyometric training on vertical jump performance (Vj, maximal surface EMG, M-wave amplitude, Mwave latency, and nerve conduction velocity (NCV in men volleyball player. Thirty junior high school volleyball players' volunteers (age: 17.53 0.74; Height: 177.67 3.14; Weight: 61.31 5.32 were divided into plyometric training [PT] (n=15 and control group[c] (n=15. PT group trained so.w' but C group didn't participate in this training. Both groups were pre- and post tested in EMG, M-wave parameters, NCV and Vj test. Tow way ANOVA (group*time interaction and Bonferroni post hoes test demonstrated significant differences (P<0.05 in PT group of pre to post test in VJ performance (9.67 % and in M-wave latency 16.55 % t ; nerve conduction velocity 14.19 % t ; there is no significant differences in IEMG (4.6 5 % J, and M-wave amplitude (20.91 % t , but there is no significant improvement during this period in control group. Comparison between groups after 12wk showed that there was a significant improvement in Latency (16.74 % J, and NCV (19.10% t in PT group during the course of the study than C group (P<0.05. based on the results of this study, it is possible to conclude that coaches and trainers consider PT as a strategy for increasing volleyball players' explosive performance that this may have taken place in neuromuscular responses such as; optimizing motor unites (MU pattern, optimizing MUs recruitment, augmentation in nerve conduction velocity, decrement in reflex excitability of the motor pool.

  20. Utility of Genetic Testing in Elite Volleyball Players with Aortic Root Dilation.

    Science.gov (United States)

    Herrick, Nicole; Davis, Christopher; Vargas, Lisa; Dietz, Hal; Grossfeld, Paul

    2017-07-01

    Basketball and volleyball attract individuals with a characteristic biophysical profile, mimicking features of Marfan syndrome. Consequently, identification of these abnormalities can be lifesaving. To determine how physical examination, echocardiography, and genetic screening can identify elite volleyball players with a previously undiagnosed aortopathy. We have performed cardiac screening on 90 US Volleyball National Team members and identified four individuals with dilated sinuses of Valsalva. This case series reports on three individuals who underwent a comprehensive genetics evaluation, including gene sequencing. Cardiac screening combined with genetic testing can identify previously undiagnosed tall athletes with an aortopathy, in the absence of noncardiac findings of a connective tissue disorder. Subject 1 had a revised Ghent systems (RGS) score of 2 and a normal aortopathy gene panel. Subject 2 had a RGS score of 1 and genetic testing revealed a de novo disease causing mutation in the gene encoding fibrillin-1 (FBN1). Subject 3 had an RGS score of 4.0 and had a normal aortopathy gene panel. Despite variable clinical features of Marfan syndrome, dilated sinuses of Valsalva were found in 4.9% of the athletes. A disease-causing mutation in the FBN1 gene was identified in subject 2, who had the lowest RGS but the largest aortic root measurement. Subjects 1 and 3, with the highest RGS, had a normal aortopathy gene panel. Our findings provide further evidence suggesting that a cardiac evaluation, including a screening echocardiogram, should be performed on all elite tall adult athletes independent of other physical findings. Genetic testing should be considered for athletes with dilated sinuses of Valsalva (male, >4.2 cm; female, >3.4 cm), regardless of other extracardiac findings.

  1. Comparison of biomechanical parameters obtained during various types of vertical jumps in volleyball and basketball players

    Directory of Open Access Journals (Sweden)

    Joanna Mazur-Różycka

    2017-07-01

    Full Text Available The aim of the study was to compare selected biomechanical parameters obtained during various types of vertical jumps made by volleyball and basketball players on a dynamometric platform. The study involved 10 volleyball players and 10 basketball players in the age of 21.1 ± 1.81 years of the AZS AWF Warsaw sport club. The athletes performed two vertical jumps on a KISTLER platform. The first jump was a counter-movement jump (CMJ and the second was a spike jump (SPJ – a vertical jump which is performed with a 3-4 step run-up before the take-off. The participant's task was to take off and land on the platform. On the basis of the statistical analysis it was shown that only the type of jump had a significant effect on the height and power. The type of team sport did not affect the level of performance. In addition, it was found that the height of the jump is affected by the counter movement phase with hand swing and run-up. The volleyball and basketball players were equally able to get higher values for certain parameters in successive runs. Due to lack of statistically significant differences it was decided to combine two groups of athletes into one. For both jumps, the relationship between peak power and jump height was found at significance level p <0.001. Dynamometric platform can be used to check the athlete's height of jump and power of lower extremities. This method allows to verify the effectiveness of different types of training.

  2. Injuries in Collegiate Women’s Volleyball: A Four-Year Retrospective Analysis

    Science.gov (United States)

    Sole, Christopher J.; Kavanaugh, Ashley A.; Stone, Michael H.

    2017-01-01

    A four-year retrospective analysis of injury data was conducted on a collegiate (NCAA Division I) women’s volleyball team. Twenty athletes (Year 1: age = 19.4 ± 0.9 y, height = 175.2 ± 5.1 cm, body mass = 70.5 ± 10.2 kg; Year 2: age = 20.1 ± 1.0 y, height = 175.7 ± 4.7 cm, body mass = 69.5 ± 10.1 kg; Year 3: age = 20.1 ± 1.4 y, height = 173.8 ± 6.3 cm, body mass = 69.9 ± 10.8 kg; Year 4: age = 19.5 ± 1.4 y, height = 174.4 ± 8.6 cm, body mass = 72.7 ± 10.8 kg) participated in this study, accounting for 1483 total training exposures. Injury was defined as any damage to a body part, incurred during volleyball or strength and conditioning-related activities, which interfered with training and/or competition. Injury rate was normalized to the number of athletes and exposure and expressed as injuries per 1000 exposures. A total of 133 injuries were recorded. The most common injury was to the knee (left = 7.5%, right = 12.0%). Injuries occurred most often in volleyball practice (75.2%), followed by competition (20.3%), and strength and conditioning-related activities (4.5%). Non-contact injuries (upper body = 26.3%, lower body = 53.4%) were more common than contact injuries (upper-body = 13.5%, lower-body = 6.8%). An examination of injury rates relative to the training year revealed patterns in injury occurrence. Specifically, spikes in injury rate were consistently observed during periods of increased training volume that were preceded by breaks in organized training, such as the early pre-season and off-season training periods.

  3. Anterior cruciate ligament injury profile in Italian Serie A1-A2 women's volleyball league.

    Science.gov (United States)

    Devetag, Francesca; Mazzilli, Massimiliano; Benis, Roberto; LA Torre, Antonio; Bonato, Matteo

    2018-01-01

    The aim of this study was to assess how anterior cruciate ligament (ACL) ruptures with subsequent surgery reconstruction impact on the professional career of A1-A2 Italian women's volleyball league players. Using an observational study with a retrospective case-series design for ACL ruptures, 125 teams with 1488 players were monitored. Subjects had to report level, role, injury modality, lower limb injured, laterality, period of the season and age. A total of 34 ACL ruptures were reported. Thirty-three (97%) were non-contact and 1 (3%) with contact. Twenty-one (61.7%) occurred in landing from a jump attack, 3 (8.8%) in landing from wall jump, 1 (3%) with apparent contact and 9 (26.5%) in other landing conditions. The most injured knee was the left limb (22, 64.7%) respect to the right limb (12, 35.3%). Fourteen (41.2%) ruptures occurred in spikers, 10 (29.4%) in middle blockers, 6 (17.6%) in setters, 3 (8.8%) in liberos and 1 (3%) in opposite hitters. Nine (26.5%) occurred in pre-season period, 16 (47%) in the first round, 4 (11.8%) in the second round, and 5 (14.7%) during play-off. The average age of the first ACL rupture was 23±3 years. We observed that female volleyball players of A1-A2 Italian volleyball league occurred mostly in a left non-contact ACL rupture during a landing condition and the spikers were the players most at risk. Therefore, it is desirable that coaches teach players variations of landing in order to avoid possible chronic overloading of ACL.

  4. BMP4 and FGF3 haplotypes increase the risk of tendinopathy in volleyball athletes.

    Science.gov (United States)

    Salles, José Inácio; Amaral, Marcus Vinícius; Aguiar, Diego Pinheiro; Lira, Daisy Anne; Quinelato, Valquiria; Bonato, Letícia Ladeira; Duarte, Maria Eugenia Leite; Vieira, Alexandre Rezende; Casado, Priscila Ladeira

    2015-03-01

    To investigate whether genetic variants can be correlated with tendinopathy in elite male volleyball athletes. Case-control study. Fifteen single nucleotide polymorphisms within BMP4, FGF3, FGF10, FGFR1 genes were investigated in 138 elite volleyball athletes, aged between 18 and 35 years, who undergo 4-5h of training per day: 52 with tendinopathy and 86 with no history of pain suggestive of tendinopathy in patellar, Achilles, shoulder, and hip abductors tendons. The clinical diagnostic criterion was progressive pain during training, confirmed by magnetic resonance image. Genomic DNA was obtained from saliva samples. Genetic markers were genotyped using TaqMan real-time PCR. Chi-square test compared genotypes and haplotype differences between groups. Multivariate logistic regression analyzed the significance of covariates and incidence of tendinopathy. Statistical analysis revealed participant age (p=0.005) and years of practice (p=0.004) were risk factors for tendinopathy. A significant association between BMP4 rs2761884 (p=0.03) and tendinopathy was observed. Athletes with a polymorphic genotype have 2.4 times more susceptibility to tendinopathy (OR=2.39; 95%CI=1.10-5.19). Also, association between disease and haplotype TTGGA in BMP4 (p=0.01) was observed. The FGF3 TGGTA haplotype showed a tendency of association with tendinopathy (p=0.05), and so did FGF10 rs900379. FGFR1 showed no association with disease. These findings indicate that haplotypes in BMP4 and FGF3 genes may contribute to the tendon disease process in elite volleyball athletes. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. Using Microsensor Technology to Quantify Match Demands in Collegiate Women's Volleyball.

    Science.gov (United States)

    Vlantes, Travis G; Readdy, Tucker

    2017-12-01

    Vlantes, TG and Readdy, T. Using microsensor technology to quantify match demands in collegiate women's volleyball. J Strength Cond Res 31(12): 3266-3278, 2017-The purpose of this study was to quantify internal and external load demands of women's NCAA Division I collegiate volleyball competitions using microsensor technology and session rating of perceived exertion (S-RPE). Eleven collegiate volleyball players wore microsensor technology (Optimeye S5; Catapult Sports, Chicago, IL, USA) during 15 matches played throughout the 2016 season. Parameters examined include player load (PL), high impact PL, percentage of HI PL, explosive efforts (EEs), and jumps. Session rating of perceived exertion was collected 20 minutes postmatch using a modified Borg scale. The relationship between internal and external load was explored, comparing S-RPE data with the microsensor metrics (PL, HI PL, % HI PL, EEs, and jumps). The setter had the greatest mean PL and highest number of jumps of all positions in a 5-1 system, playing all 6 rotations. Playing 4 sets yielded a mean PL increase of 25.1% over 3 sets, whereas playing 5 sets showed a 31.0% increase in PL. A multivariate analysis of variance revealed significant differences (p < 0.01) across all position groups when examining % HI PL and jumps. Cohen's d analysis revealed large (≥0.8) effect sizes for these differences. Defensive specialists recorded the greatest mean S-RPE values over all 15 matches (886 ± 384.6). Establishing positional load demands allows coaches, trainers, and strength and conditioning professionals to implement training programs for position-specific demands, creating consistent peak performance, and reducing injury risk.

  6. Epidemiology of Basketball, Soccer, and Volleyball Injuries in Middle-School Female Athletes

    Science.gov (United States)

    Barber Foss, Kim D.; Myer, Greg D.; Hewett, Timothy E.

    2014-01-01

    Background An estimated 30 to 40 million school children participate in sports in the United States; 34% of middle-school participants become injured and seek medical treatment at an annual cost close to $2 billion. The purpose of the current study was to evaluate the injury incidence and rates in female athletes in the middle-school setting during the course of 3 seasons. Methods Female basketball, soccer, and volleyball players were recruited from a single county public school district in Kentucky consisting of 5 middle schools. A total of 268 female athletes (162 basketball, 26 soccer, and 80 volleyball) participated. Athletes were monitored for sports-related injury and number of athlete exposures (AEs) by an athletic trainer. Injury rates were calculated for specific types of injuries within each sport. Injury rates for games and practices were also calculated and compared for each sport. Results A total of 134 injuries were recorded during the 3 sport seasons. The knee was the most commonly injured body part (99 injuries [73.9%]), of which patellofemoral dysfunction (31.3%), Osgood-Schlatter disease (10.4%), and Sinding-Larsen-Johansson/patella tendinosis (9%) had the greatest incidence. The ankle was the second most commonly injured body part, accounting for 16.4% of all injuries. The overall rates of injury by sport were as follows: soccer, 6.66 per 1000 AEs; volleyball, 3.68 per 1000 AEs; and basketball, 2.86 per 1000 AEs. Conclusions Female middle-school athletes displayed comparable injury patterns to those seen in their high-school counterparts. Future work is warranted to determine the potential for improved outcomes in female middle-school athletes with access to athletic training services. Clinical Relevance As the participation levels and number of injuries continue to rise, middle-school athletes demonstrate an increasing need for medical services provided by a certified athletic trainer. PMID:24875981

  7. A Comparison of Isokinetic Knee Strength and Power Output Ratios Between Female Basketball and Volleyball Players

    Directory of Open Access Journals (Sweden)

    Kabaciński Jarosław

    2017-09-01

    Full Text Available Purpose. Tests such as the counter movement jump (CMJ and squat jump (SJ allow for determining the ratio of maximal power output generated during SJ to CMJ (S/C. The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q is defined as functional H/Q. The purpose of this study was to compare the S/C and functional H/Q between female basketball and volleyball players. Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years and 12 female volleyball players (age, 22.3 ± 4.2 years participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed. Results. The results of the S/C and functional H/Q at 90 deg · s-1/60 deg · s-1 velocities were higher in basketball players (87.3 ± 9.1% and 91.4 ± 9.3%, respectively than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively. No significant differences in S/C or functional H/Q values between the two groups were found (p > 0.05. Conclusions. Decreasing the S/C may result from an improvement in the power output during CMJ and a better utilization of the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can provide dynamic knee joint stabilization.

  8. Effect of a Volleyball Course on Health-Related Fitness Components of University Students

    Directory of Open Access Journals (Sweden)

    Mohammed Hamdan Hashem Mohammed

    2018-02-01

    Full Text Available Physical educators need to evaluate the physical education (PE curriculum they provide to their students. One way is through regular health-related fi tness assessments. Physical education programs have improved fi tness levels of schoolchildren, but such data is rare for university students. The aim of this study was to determine the eff ect of a volleyball course on the health-related fi tness of male university students. The participants were non-PE majors from King Fahd University of Petroleum & Minerals. They registered for a volleyball course which was done twice a week for eight weeks (31 October-29 December 2016, 50 minutes per session. The parameters assessed were as follows: 1 body composition through body mass index (BMI, 2 muscular endurance through the 60s curl-up test, 3 fl exibility through the sit and reach test, 4 leg explosive strength through standing long jump, and 5 cardiovascular endurance through a 1.6 km run. Pre and post measurements were taken and the data were analyzed using descriptive statistics and paired t-test with SPSS 16. P-values for statistical signifi cance was set at0.2 was considered of practical signifi cance. Data from 145 students were analyzed (mean (SD age=20.8 (0.64 years. There were improvements from pre to post in all variables except body mass and BMI. The data shows evidence that the volleyball course improved the health-related fi tness variables of the students. This shows a course designed for non-PE majors may improve their fi tness levels if well designed.

  9. Sensorimotor Control of the Shoulder in Professional Volleyball Players with Isolated Infraspinatus Muscle Atrophy.

    Science.gov (United States)

    Contemori, Samuele; Biscarini, Andrea; Botti, Fabio Massimo; Busti, Daniele; Panichi, Roberto; Pettorossi, Vito Enrico

    2017-06-12

    Isolated infraspinatus muscle atrophy (IIMA) only affects the hitting shoulder of overhead-activity athletes, and is caused by suprascapular nerve neuropathy. No study has assessed the static and dynamic stability of the shoulder in overhead professional athletes with IIMA to reveal possible shoulder sensorimotor alterations. To assess the shoulder static stability, dynamic stability, and strength in professional volleyball players with IIMA and in healthy control players. Cross-sectional study. Research laboratory. Twenty-four male professional volleyball players (12 players with diagnosed IIMA and 12 healthy players) recruited from local volleyball teams. Static stability was evaluated with two independent force platforms and dynamic stability was assessed with the "Upper Quarter Y Balance Test". The static stability assessment was conducted in different support (single hand and both hand) and vision (open and closed eyes) conditions. Data from each test were analyzed with ANOVA and paired t-test models, to highlight statistical differences within and between groups. In addition to reduced abduction and external rotation strength, athletes with IIMA consistently demonstrated significant less static (P < 0.001) and dynamic stability (P < 0,001), compared with the contralateral shoulder and with healthy athletes. Closed eyes condition significantly enhanced the static stability deficit of the shoulder with IIMA (P = 0.039 and P = 0.034 for both hand and single hand support, respectively), but had no effect in healthy contralateral and healthy players' shoulders. This study highlights an impairment of the sensorimotor control system of the shoulder with IIMA, which likely results from both proprioceptive and strength deficits. This condition could yield subtle alteration in the functional use of the shoulder and predispose it to acute or overuse injuries. The results of this study may help athletic trainers and physical/physiotherapists to prevent shoulder injuries

  10. Namibia : triaxial test on sand

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Jacobsen, Kim P.

    In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...... of two CID, isotropically consolidated, drained triaxial tests carried out according to the instructions in DG1 letter dated 13 March 1998....

  11. THE DIFFERENCE BETWEEN TWO VOLLEYBALL TEAMS IN SOME ANTHROPOMETERIC AND MOTOR ABILITIS

    Directory of Open Access Journals (Sweden)

    Bahri Gjinovci

    2014-06-01

    Full Text Available Introduction: In this research we are deal with two teams of the super league of Kosovo in volleyball. The goal of this study is to verify the differences between the two teams in volleyball in some anthropometric characteristics, basic motor skills and situational tests. Methods: For the realization of this research, there were included 12 volleyball player from the team KV “Prishtina" and 12 from the team KV "Universiteti AAB". There are applied 4 anthropometric variables (body weight, body height, arm length, forearm length, 5 basic motor variables (long jump from place, high jump from the place taping hand, taping feet, jogging with 20 meters with a fast start, and 7 situational tests (pass the ball with the fingers on target vertical expulsion of the ball with the forearm ("hammer" in vertical target, passing the ball with the fingers in a horizontal target, the expulsion of the ball with the forearm ("hammer" in horizontal target, pass the ball with fingers to jump in the horizontal target, tennis service in horizontal target, the target service with the horizontal jump. For processing the obtained results from the measurements and proving the difference between the teams in anthrop motored parameters, was used the discriminatory analysis using the t-test for independent variables. Results: The results obtained show that the players of the two volleyball teams, involved in research do not distinguish between them in anthropometric characteristics (p> 0:05. The team KV "Prishtina" has had better results in some explosive force motor variables and situational tests (p 1.97, at the statistical significance level of p < 0.05. Results from our sample showed that between VC. "Pristina" and VC. "AAB", important statistical changes were in those motoric tests. High jumping, foot taping, Passing the ball with hammer to the wall, Tactical accurate Service, Accuracy of service with jump and Standing long jump length. References: Strahonja A

  12. Thoracic Outlet Syndrome in a Volleyball Player Due to Nonunion of the First Rib Fracture.

    Science.gov (United States)

    Puttmann, Kathleen T; Satiani, Bhagwan; Vaccaro, Patrick

    2016-11-01

    Fracture of the first rib with ensuing callus formation is a rare cause of thoracic outlet syndrome. We report a case of a 17-year-old female volleyball player who presented with months of chronic arm pain. Radiographic imaging demonstrated nonunion fracture of the first rib. Physical therapy had been unsuccessful in relieving the pain, and surgical management was performed with resection of the first rib through a transaxillary approach with complete resolution of symptoms. Inflammation surrounding such fractures may destroy tissue planes, making dissection more technically difficult.

  13. CUE USAGE IN VOLLEYBALL: A TIME COURSE COMPARISON OF ELITE, INTERMEDIATE AND NOVICE FEMALE PLAYERS

    Science.gov (United States)

    Vaeyens, R; Zeuwts, L; Philippaerts, R; Lenoir, M

    2014-01-01

    This study compared visual search strategies in adult female volleyball players of three levels. Video clips of the attack of the opponent team were presented on a large screen and participants reacted to the final pass before the spike. Reaction time, response accuracy and eye movement patterns were measured. Elite players had the highest response accuracy (97.50 ± 3.5%) compared to the intermediate (91.50 ± 4.7%) and novice players (83.50 ± 17.6%; pvolleyball and suggests that expert players extract more information from parafoveal regions. PMID:25609887

  14. ANTHROPOMETRIC AND MOTORIC COMPARISONS BETWEEN THE TWO VOLLEYBALL TEAMS IN PRISHTINA

    Directory of Open Access Journals (Sweden)

    Malsor Gjonbalaj

    2014-06-01

    Full Text Available Introduction: The increase in sports results today not only identifies the quantity (volume and intensity of the work put in, but also the quality (changing the stereotypical notion of effort, eliminating redundant movements, rationalizing the sport in all elements etc. All of these circumstances and factors referred in this paper are stimulated through practical methods for processing positive results and aiming to present a realistic and factual reflection of the current condition, particularly emphasizing the evaluation of several anthropometric and motor characteristics of the players in both volleyball clubs from Prishtina. Methods: These methods are elaborated among arithmetic methods, variance, standard deviation and standard error of the arithmetic mean, the coefficient of variance, the maximum and minimum score test, the score in accordance to the Pearson correlation coefficient-whereas the instruments measured 14 variables such as anthropometric 8, 4 motors and 2 situational. The main purpose to which is addressed in this paper is verifying the situation and the differences between the players in two of the clubs by analyzing the results from the variables I have chosen. Results: The results show that there is a significant differentiation between one volleyball group to the other in terms of motor, anthropometric and situational. This is proven by the results of the data based on the parameters abovementioned. Discussion: Results acquired on in the research, verifies the hypotheses which sets forth previously, it helps to us to understand that the main goal in this research has largely been achieved. Statistical methods that have been processed results may explain the state of anthropometric and motor characteristics. Moreover, with the help of T-test we came to understand the valuable statistical differences between two clubs which have been subject to research. These results are best justified considering the fact that the first

  15. The organization of the sport process: The perspective of elite volleyball Brazilian coaches.

    OpenAIRE

    Vieira, Ana Luiza; Dias, Cláudia Salomé Lima; Corte-Real, Nuno José; Fonseca, António Manuel

    2014-01-01

    Abstract The purpose of this study was to analyze the coaching knowledge of 24 expert high-performance Brazilian volleyball coaches in the organization of training and competition. A semi-structured interview was used, and the resulting data analyzed following the procedures outlined by Côté and colleagues (Côté & Salmela, 1994, 1996; Côté, Salmela, & Russell, 1995a, 1995b). Overall, the data highlighted that the coaches of male and female teams organized competition and train...

  16. Technology unlocks tar sands energy

    Energy Technology Data Exchange (ETDEWEB)

    Law, C

    1967-09-25

    Tar sand processing technology has been developed primarily in the categories of extraction techniques and in-situ processing. In October, a $235 million venture into tar sand processing will be inspected by visitors from many points on the globe. A synthetic crude of premium quality will be flowing through a 16-in. pipeline from the Tar Island plant site of Great Canadian Oil Sands to Edmonton. This processing plant uses an extractive mining technique. The tar sand pay zone in this area averages approximately 150 ft in thickness with a 50-ft overburden. It has been estimated that the tar sands cannot be exploited when the formation thickness is less than 100 ft and overburden exceeds the same amount. This indicates that extraction techniques can only be used to recover approximately 15% of the tar sand deposits. An in-situ recovery technique developed by Shell of Canada is discussed in detail. In essence it is selective hydraulic fracturing, followed by the injection of emulsifying chemicals and steam.

  17. Plyometric type neuromuscular exercise is a treatment to postural control deficits of volleyball players: A case study

    Directory of Open Access Journals (Sweden)

    A. Asadi

    2016-06-01

    Conclusions: It can be recommend that strength and conditioning professionals in the field of volleyball do not perform other type of landing exercise in plyometric training sessions because of postural control impaired and consequently the probability of lower extremity injuries will increase.

  18. Physical parameters and performance values in starters and non-starters volleyball players: A brief research note

    Directory of Open Access Journals (Sweden)

    M.C. Marques

    2009-09-01

    Full Text Available The aim of this paper was to investigate the anthropometric and strength characteristics of elite male volleyball athletes and determines if differences exist in these characteristics between starters (S and non-starters players (NS. A group of 22 professional male team volleyball players participated in the study and the players were categorized as S (n= 13 and NS (n= 9. Anthropometric characteristics, countermovement jump, overhead medicine ball throwing and maximal dynamic strength were evaluated in all the subjects. Significant diferences in age, hight and weight were noticed between S and NS. There were no significant differences between the two groups in strength and power values, except for squat performance, where S were significant strong than NS. These findings provide normative data for elite male volleyball players competing in specific playing status. From a practical perspective, sport scientists and conditioning professionals should take specicif lower body strength characteristics of volleyball players into account when designing individualized training stauts specific training programmes.

  19. Physical parameters and performance values in starters and non-starters volleyball players: A brief research note

    Directory of Open Access Journals (Sweden)

    M.C. Marques

    2009-01-01

    Full Text Available The aim of this paper was to investigate the anthropometric and strength characteristics of elite male volleyball athletes and determines if differences exist in these characteristics between starters (S and non-starters players (NS. A group of 22 professional male team volleyball players participated in the study and the players were categorized as S (n= 13 and NS (n= 9. Anthropometric characteristics, countermovement jump, overhead medicine ball throwing and maximal dynamic strength were evaluated in all the subjects. Significant diferences in age, hight and weight were noticed between S and NS. There were no significant differences between the two groups in strength and power values, except for squat performance, where S were significant strong than NS. These findings provide normative data for elite male volleyball players competing in specific playing status. From a practical perspective, sport scientists and conditioning professionals should take specicif lower body strength characteristics of volleyball players into account when designing individualized training stauts specific training programmes.

  20. Vascular Endothelial Growth Factor Receptor-2 Polymorphisms Have Protective Effect against the Development of Tendinopathy in Volleyball Athletes.

    Science.gov (United States)

    Salles, José Inácio; Duarte, Maria Eugenia Leite; Guimarães, João Matheus; Lopes, Lucas Rafael; Vilarinho Cardoso, Jessica; Aguiar, Diego Pinheiro; Machado Neto, João Olyntho; Machado, Daniel Escorsim; Perini, Jamila Alessandra

    2016-01-01

    The aim of the study was to investigate whether genetic variants in VEGF and KDR genes can be correlated with susceptibility of tendinopathy in volleyball athletes. This study was conducted at the Brazilian Volleyball Federation, and comprised 179 volleyball athletes: 88 had a confirmed diagnosis of tendinopathy (cases), whereas 91 had no evidence of the disease (controls). The VEGF (-2578C>A, -460T>C and +936C>T) and KDR (-604C>T, 1192G>A and 1719T>A) polymorphisms were determined by TaqMan real-time polymerase chain reaction. The odds ratio (OR) with their 95% confidence intervals (CI) were calculated using an unconditional logistic regression model. The evaluation of demographic and clinical characteristics revealed the athlete age (P volleyball (P T, 1192G>A and 1719T>A) haplotypes CGA and CAT were associated with decreased tendinopathy risk (OR: 0.46, 95% CI: 0.21-0.99 and OR: 0.23, 95% CI: 0.07-0.76, respectively). With regards to pain, traumatic lesion and away from training due to injury, VEGF and KDR polymorphisms were not associated with clinical symptoms complaints. The present results provide evidence that the KDR polymorphisms were associated with development of tendinopathy, and can contribute to identify new therapeutic targets or personalized training programs to avoid tendinopathy development in athletes.

  1. Proficiency Assessment of Male Volleyball Teams of the 13-15-Year Age Group at Estonian Championships

    Science.gov (United States)

    Stamm, Meelis; Stamm, Raini; Koskel, Sade

    2008-01-01

    Study aim: Assessment of feasibility of using own computer software "Game" at competitions. Material and methods: The data were collected during Estonian championships in 2006 for male volleyball teams of the 13-15-years age group (n = 8). In all games, the performance of both teams was recorded in parallel with two computers. A total of…

  2. Anatomical glenohumeral internal rotation deficit and symmetric rotational strength in male and female young beach volleyball players.

    Science.gov (United States)

    Saccol, Michele Forgiarini; Almeida, Gabriel Peixoto Leão; de Souza, Vivian Lima

    2016-08-01

    Beach volleyball is a sport with a high demand of shoulder structures that may lead to adaptations in range of motion (ROM) and strength like in other overhead sports. Despite of these possible alterations, no study evaluated the shoulder adaptations in young beach volleyball athletes. The aim of this study was to compare the bilateral ROM and rotation strength in the shoulders of young beach volleyball players. Goniometric passive shoulder ROM of motion and isometric rotational strength were evaluated in 19 male and 14 female asymptomatic athletes. External and internal ROM, total rotation motion, glenohumeral internal rotation deficit (GIRD), external rotation and internal rotation strength, bilateral deficits and external rotation to internal rotation ratio were measured. The statistical analysis included paired Student's t-test and analysis of variance with repeated measures. Significantly lower dominant GIRD was found in both groups (pvolleyball athletes present symmetric rotational strength and shoulder ROM rotational adaptations that can be considered as anatomical. These results indicate that young practitioners of beach volleyball are subject to moderate adaptations compared to those reported for other overhead sports. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Nutritional analysis of dietary intake of professional female volleyball players during the competitive phase of the regular season

    Directory of Open Access Journals (Sweden)

    Juan Mielgo-Ayuso

    2013-03-01

    Full Text Available Introduction: nutritional aspects women’s volleyball has been little studied and more in a specific period of training as the competitive period. The aim is to assess and know the caloric and macronutrients intake by professional volleyball players of the Spanish Superliga for 16 weeks of training for the competition phase and compare with the references marked for athlete population.Material and methods: the study included 10 female volleyball players (JVF (26.6±5.9 years and height 178.05±8.7cm, for a total of 16 weeks of training and competition. They all gave written informed consent. They completed a food intake frequency questionary of the 16 week study, data corroborated by a dietary record (CFCA of 7 consecutive days in week 9 and 16. We were calculated daily nutritional intake from CFCA with the food composition table of CESNID by Easy Diet software, the Spanish Association of Dietitians-Nutritionists (AEDN.Results: the energy and nutritional analysis of the female professional volleyball players shows that the amount of energy and macronutrients does not meet to the recommendations for sports collective.Conclusions: it is observed low energy and carbohydrates intake and high intake of protein and lipids. Recommended practical aspects for improving nutrition education in this professional sports group.

  4. The estimation of the correlation between technical-tactical and special physical performance in qualified women volleyball players

    OpenAIRE

    Wnorowski, Krzysztof; Smulskij, Walerij

    2007-01-01

    The article deals with the correlation between technical-tactical and special physical performance in qualified women volleyball players. The experts estimation of technical-tactical performance and seven indices of special physical capacities of athletes were correlated. Most correlation (r = 0,68; p

  5. The influence of the external ankle support on the dynamic balance in volleyball athletes

    Directory of Open Access Journals (Sweden)

    Manuela Azevedo Correia de Lima

    2015-09-01

    Full Text Available AbstractThe purpose of this study was to assess the effect of ankle external supports on proprioception and dynamic balance in volleyball players. Seventeen female volleyball players (18.94±2.49 years; 65.45±9.49 kg; 1.71±0.05 m; BMI=22.0±2.67 kg/m² took part in this study. The dynamic balance was assessed through the Star Excursion Balance Test (SEBT. Comparisons between stabilization (no stabilizer/NS, orthosis/ORT and functional bandaging/FB modes and the SEBT grid lines and inter-limb were carried out. The SEBT assessment showed a significant difference between the groups NS x ORT and NS x FB (p < .01, and between the lines (p< .01. Significant line/limb interaction in DL and NDL (p< .01 was detected. The external supports tested herein showed similar effects on balance, restricting lower limb's reach in the SEBT execution in some of tested directions.

  6. Specific warm-up exercise is the best for vertical countermovement jump in young volleyball players

    Directory of Open Access Journals (Sweden)

    Fernando Nazário de Rezende

    Full Text Available Abstract We evaluated the effect of performing various distinct warm-up exercises on vertical countermovement jump (VCMJ performance. Eight volleyball players (age 15.4 ± 0.5 yrs performed five different warm-up activities (in a counterbalanced, randomized crossover study over five days, at 24-h intervals: stretching (4 × 30 s, 30 s between sets, cycloergometer (5 min at 50 W + 5 min at 100 W, resistance exercise (leg press 45°, 3 × 5 repetitions maximum, 3-min pause between sets, specific vertical jumping (4 × 10 VCMJ, 2-min pause between sets, and no warm-up at all (control condition. Beginning 3 min after their warm-up, the players performed 3 attempts (at intervals of 3 min of VCMJ (on a contact carpet, and each player's best jump was considered in the analysis. All warm-up activities presented higher VCMJ performance (p< 0.05 than the control condition, with the exception of stretching. Vertical jumping revealed a large effect size(0.8 than other interventions. We conclude that in practical terms, vertical jumps are the best warm-up exercise (when applied by itself to acutely improve VCMJ performance in volleyball players, but that other exercises can make a complementary contribution.

  7. Sleep Quality, Mood and Performance: A Study of Elite Brazilian Volleyball Athletes

    Directory of Open Access Journals (Sweden)

    Alexandro Andrade, Guilherme G. Bevilacqua, Danilo R. Coimbra, Fabiano S. Pereira, Ricardo Brandt

    2016-12-01

    Full Text Available This investigation analyzed the relationships between sleep quality, mood, and game results in the elite athletes participating in Brazilian volleyball competitions. Participants (n = 277 elite Brazilian volleyball athletes, 214 (77.3% men and 63 (22.7% women completed the Brunel Mood Scale (BRUMS and reported their subjective sleep perception. Athletes with poor sleep quality reported higher scores for confusion compared to athletes with good sleep quality (p < 0.01, d = 0.43. In addition, athletes who lost their game at the time of evaluation showed higher tension (p < 0.01, d = 0.49 and confusion (p < 0.01, d = 0.32 levels compared to athletes who won their game. A regression analysis demonstrated that for each point increase in the confusion level, there was a 19.7% reduction in sleep quality. Multivariate analysis of variance indicated that athletes who slept well, and won their games, had lower tension levels. Further, our results indicated that the athletes’ mood associated with their success in the competitions. Therefore, in a competition, it is important that the athletes show good sleep quality, and use techniques and strategies to ease their mood variations.

  8. The Cognitive and Motivation Intervention Program in Youth Female Volleyball Players

    Directory of Open Access Journals (Sweden)

    Claver Fernando

    2017-10-01

    Full Text Available This study, grounded in Self-Determination Theory (Deci and Ryan, 1985, 2002 was aimed to determine the influence of a cognitive-motivational intervention program, to improve the basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment, in youth volleyball players. Participants included 34 Under-19 female volleyball players. A quasi-experimental design was carried out with an experimental group (n = 16; M = 17.45; SD = .45 and a control group (n = 18; M = 16.64; SD = .70. The experimental group followed a multidimensional intervention program comprised of 24 sessions held over three months (two training sessions per week. It was based on two strategies: giving athletes the possibility of choice in specific training tasks (proposing training situations with several action alternatives and questioning (cognitively involving players through tactical questions. A repeated-measures MANOVA 2 (group: experimental and control x 2 (time: pre-test and post-test was used to analyse the effect of Group x Time interaction. The results of the inter-group analysis showed significant differences in the post-test measurement between the experimental group and the control group (in favour of the experimental group in the variables: basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment. Given the relevance of the cognitive-motivational processes, not only for performance but also for sport commitment, this intervention has important implications for sport coaching.

  9. The Cognitive and Motivation Intervention Program in Youth Female Volleyball Players.

    Science.gov (United States)

    Claver, Fernando; Jiménez, Ruth; Gil-Arias, Alexander; Moreno, Alberto; Moreno, M Perla

    2017-10-01

    This study, grounded in Self-Determination Theory (Deci and Ryan, 1985, 2002) was aimed to determine the influence of a cognitive-motivational intervention program, to improve the basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment, in youth volleyball players. Participants included 34 Under-19 female volleyball players. A quasi-experimental design was carried out with an experimental group (n = 16; M = 17.45; SD = .45) and a control group (n = 18; M = 16.64; SD = .70). The experimental group followed a multidimensional intervention program comprised of 24 sessions held over three months (two training sessions per week). It was based on two strategies: giving athletes the possibility of choice in specific training tasks (proposing training situations with several action alternatives) and questioning (cognitively involving players through tactical questions). A repeated-measures MANOVA 2 (group: experimental and control) x 2 (time: pre-test and post-test) was used to analyse the effect of Group x Time interaction. The results of the inter-group analysis showed significant differences in the post-test measurement between the experimental group and the control group (in favour of the experimental group) in the variables: basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment. Given the relevance of the cognitive-motivational processes, not only for performance but also for sport commitment, this intervention has important implications for sport coaching.

  10. Anthropometric and performance measures to study talent detection in youth volleyball.

    Science.gov (United States)

    Melchiorri, Giovanni; Viero, Valerio; Triossi, Tamara; Annino, Giuseppe; Padua, Elvira; Tancredi, Virginia

    2017-12-01

    The aim of this work was to study anthropometric and performance measurements in 60 young male volleyball players (YV) and 60 youth not active in the sport (YNA) to assess which of these would be more useful to study the characteristics of potential performers. Eight measures to assess anthropometric characteristics, six performance measures and two tests for joint mobility were used. Also relative age and level of maturation were assessed. The anthropometric variables, relative age and level of maturation measured did not show statistically significant differences between groups. The YV and YNA groups showed differences in the performance measures. YV group was characterized by a better performance of the ability to repeat short sprints, of the upper limbs, abdominal muscles and lower limbs, with a medium effect size (Shuttle Running Test: 0.6; Push-Up: 0.5; Sit-Up: 0.4; counter movement jump: 0.4). These performance variables were very sensitive and specific: the SRT measurement had the best positive likelihood ratio that indicates the utility of the test in identifying type of players (YV and YNA). In talent detection in youth volleyball, in the 11-13 age range, performance variables should be preferred to anthropometric ones.

  11. Effectiveness of PETTLEP imager on performance of passing skill in volleyball.

    Science.gov (United States)

    Afrouzeh, M; Sohrabi, E; Haghkhan, A; Rowshani, F; Goharrokhi, S

    2015-01-01

    This study was conducted to compare the effectiveness of PETTLEP-based imagery, and traditional imagery interventions, on performance of passing skill in volleyball. 36 beginners male volleyball players (Mage =13.5 years, SD=0.55 years) with 5-6 months practice experience were randomly assigned to one of three groups: physical practice + PETTLEP imagery (PP+PI) (N.=15), physical practice + traditional imagery (N.=15), and physical practice only (PP; N.=15). Subjects in the PP+PI group applied the seven components of PETTLEP imagery training; whereas subjects in the PP+TI engaged in a relaxation session before imagery and used response laden motor imagery scripts. The two groups completed 15 minutes of imagery training followed immediately by 13 minutes of "passing" practice three times per week. The PP group completed only 13 minutes of "passing" practice three times per week. Each group performed its respective tasks for 7 weeks. A pre-test took place during the first practice session in which "passing" was assessed. After the 7-week practice program, a post-test took place followed by a retention test, one "no-practice" week later. All groups improved significantly (Pvolleyball when combined with physical practice.

  12. Loaded and unloaded jump performance of top-level volleyball players from different age categories

    Science.gov (United States)

    Kitamura, Katia; Pereira, Lucas Adriano; Kobal, Ronaldo; Cal Abad, Cesar Cavinato; Finotti, Ronaldo; Nakamura, Fábio Yuzo

    2017-01-01

    The aim of this study was to investigate the differences in loaded and unloaded jump performances between different age categories of top-level volleyball players from the same club. Forty-three volleyball players were divided into four age groups: under-17, under-19, under-21 and professional. Vertical jumping height for squat jump (SJ), countermovement jump (CMJ) and CMJ with arm swing (CMJa) and mean propulsive velocity (MPV) in the loaded jump squat exercise with 40% of the athlete’s body mass were compared among the different age categories, considering body mass as a covariate. SJ and CMJ jump height values were higher for professional and under-21 players than under-17 players (pvolleyball players. Therefore, to increase the vertical jumping ability of these team sport athletes throughout their long-term development, coaches and strength and conditioning professionals are encouraged to implement consistent neuromuscular training strategies, in accordance with the specific needs and physiological characteristics of each age group. PMID:29158621

  13. Identification of types of landings after blocking in volleyball associated with risk of ACL injury.

    Science.gov (United States)

    Zahradnik, David; Jandacka, Daniel; Farana, Roman; Uchytil, Jaroslav; Hamill, Joseph

    2017-03-01

    Landing with a low knee flexion angle after volleyball block jumps may be associated with an increased risk of anterior cruciate ligament (ACL) injury. The aim of the present study was to identify the types of volleyball landings after blocks where the knee flexion angle is found to be under a critical knee flexion angle value of 30° at the instant of the first peak of the ground reaction force (GRF). Synchronized kinematic and kinetic data were collected for each trial. T-tests were used to determine if each knee flexion angle at the instant of the peak GRF was significantly different from the critical value of 30°. A repeated measures ANOVA was used to compare knee flexion angle, time to first peak and the magnitude of the first peak of the resultant GRF and knee stiffness. Significantly lower knee flexion angles were found in the "go" landing (p = .01, ES = 0.6) and the "reverse" landing (p = .02, ES = 0.6) only. The results for knee flexion angle and GRF parameters indicated a significant difference between a "reverse" and "go" and other types of landings, except the "side stick" landing for GRF. The "reverse" and "go" landings may present a risk for ACL injury due to the single-leg landing of these activities that have an associated mediolateral movement.

  14. Application of a tri-axial accelerometer to estimate jump frequency in volleyball.

    Science.gov (United States)

    Jarning, Jon M; Mok, Kam-Ming; Hansen, Bjørge H; Bahr, Roald

    2015-03-01

    Patellar tendinopathy is prevalent among athletes, and most likely associated with a high jumping load. If methods for estimating jump frequency were available, this could potentially assist in understanding and preventing this condition. The objective of this study was to explore the possibility of using peak vertical acceleration (PVA) or peak resultant acceleration (PRA) measured by an accelerometer to estimate jump frequency. Twelve male elite volleyball players (22.5 ± 1.6 yrs) performed a training protocol consisting of seven typical motion patterns, including jumping and non-jumping movements. Accelerometer data from the trial were obtained using a tri-axial accelerometer. In addition, we collected video data from the trial. Jump-float serving and spike jumping could not be distinguished from non-jumping movements using differences in PVA or PRA. Furthermore, there were substantial inter-participant differences in both the PVA and the PRA within and across movement types (p volleyball. A method for acquiring real-time estimates of jump frequency remains to be verified. However, there are several alternative approaches, and further investigations are needed.

  15. Decreased Circulating mtDNA Levels in Professional Male Volleyball Players.

    Science.gov (United States)

    Nasi, Milena; Cristani, Alessandro; Pinti, Marcello; Lamberti, Igor; Gibellini, Lara; De Biasi, Sara; Guazzaloca, Alessandro; Trenti, Tommaso; Cossarizza, Andrea

    2016-01-01

    Exercise exerts various effects on the immune system, and evidence is emerging on its anti-inflammatory effects; the mechanisms on the basis of these modifications are poorly understood. Mitochondrial DNA (mtDNA) released from damaged cells acts as a molecule containing the so-called damage-associated molecular patterns and can trigger sterile inflammation. Indeed, high plasma levels of mtDNA are associated to several inflammatory conditions and physiological aging and longevity. The authors evaluated plasma mtDNA in professional male volleyball players during seasonal training and the possible correlation between mtDNA levels and clinical parameters, body composition, and physical performance. Plasma mtDNA was quantified by real-time PCR every 2 mo in 12 professional volleyball players (PVPs) during 2 consecutive seasons. As comparison, 20 healthy nonathlete male volunteers (NAs) were analyzed. The authors found lower levels of mtDNA in plasma of PVPs than in NAs. However, PVPs showed a decrease of circulating mtDNA only in the first season, while no appreciable variations were observed during the second season. No correlation was observed among mtDNA, hematochemical, and anthropometric parameters. Regular physical activity appeared associated with lower levels of circulating mtDNA, further confirming the protective, anti-inflammatory effect of exercise.

  16. Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball

    Science.gov (United States)

    Giannopoulos, Nikiforos; Vagenas, George; Noutsos, Konstantinos; Barzouka, Karolina; Bergeles, Nikolaos

    2017-01-01

    Abstract This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2) and playing position (hitters vs. centers vs. opposites) considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs. PMID:28828084

  17. Validation of the VERT wearable jump monitor device in elite youth volleyball players

    Science.gov (United States)

    Borges, Thiago O.; Moreira, Alexandre; Bacchi, Renato; Finotti1, Ronaldo L.; Ramos, Mayara; Lopes, Charles R.

    2017-01-01

    This technical report aims to determine the validity and the accuracy of the VERT Wearable Jump Monitor. The participants of this study were all experienced volleyball players from the U18 category from the Brazilian National team. To assess jump performance, the VERT scores were compared to the VERTEC (jump and reach device). Each athlete performed 3 attack and 3 block jumps in a random, counterbalanced order, and the average score was registered. In the attack jumps, the VERTEC and VERT mean ± SD scores were 70.9±8.2 and 76.3±7.5 cm, respectively, and the typical error of the estimate (TEE) as a coefficient of variation (CV) was 7.8% (90% CL 7.0 to 8.9%). VERTEC and VERT devices presented a very large Pearson’s correlation for attack jumps (r=0.75; 90% CL 0.68 to 0.81). In addition, the mean±SD block jumps were 53.7±6.1 and 58.5±5.7 cm for the VERTEC and VERT, respectively and the TEE as a CV was 7.9% (90% CL 7.1 to 8.9%). Pearson’s correlation coefficient was very large for block jumps (r=0.75; 90% CL 0.67 to 0.81). The VERT device was found to be a very practical tool to quantify jump performance in volleyball players. PMID:29158616

  18. Analysis of Setting Efficacy in Young Male and Female Volleyball Players.

    Science.gov (United States)

    González-Silva, Jara; Domínguez, Alberto Moreno; Fernández-Echeverría, Carmen; Rabaz, Fernando Claver; Arroyo, M Perla Moreno

    2016-12-01

    The main objective of this study was to analyse the variables that predicted setting efficacy in complex I (KI) in volleyball, in formative categories and depending on gender. The study sample was comprised of 5842 game actions carried out by the 16 male category and the 18 female category teams that participated in the Under-16 Spanish Championship. The dependent variable was setting efficacy. The independent variables were grouped into: serve variables (a serve zone, the type of serve, striking technique, an in-game role of the server and serve direction), reception variables (a reception zone, a receiver player and reception efficacy) and setting variables (a setter's position, a setting zone, the type of a set, setting technique, a set's area and tempo of a set). Multinomial logistic regression showed that the best predictive variables of setting efficacy, both in female and male categories, were reception efficacy, setting technique and tempo of a set. In the male category, the jump serve was the greatest predictor of setting efficacy, while in the female category, it was the set's area. Therefore, in the male category, it was not only the preceding action that affected setting efficacy, but also the serve. On the contrary, in the female category, only variables of the action itself and of the previous action, reception, affected setting efficacy. The results obtained in the present study should be taken into account in the training process of both male and female volleyball players in formative stages.

  19. Analysis of Setting Efficacy in Young Male and Female Volleyball Players

    Directory of Open Access Journals (Sweden)

    González-Silva Jara

    2016-12-01

    Full Text Available The main objective of this study was to analyse the variables that predicted setting efficacy in complex I (KI in volleyball, in formative categories and depending on gender. The study sample was comprised of 5842 game actions carried out by the 16 male category and the 18 female category teams that participated in the Under-16 Spanish Championship. The dependent variable was setting efficacy. The independent variables were grouped into: serve variables (a serve zone, the type of serve, striking technique, an in-game role of the server and serve direction, reception variables (a reception zone, a receiver player and reception efficacy and setting variables (a setter‘s position, a setting zone, the type of a set, setting technique, a set’s area and tempo of a set. Multinomial logistic regression showed that the best predictive variables of setting efficacy, both in female and male categories, were reception efficacy, setting technique and tempo of a set. In the male category, the jump serve was the greatest predictor of setting efficacy, while in the female category, it was the set’s area. Therefore, in the male category, it was not only the preceding action that affected setting efficacy, but also the serve. On the contrary, in the female category, only variables of the action itself and of the previous action, reception, affected setting efficacy. The results obtained in the present study should be taken into account in the training process of both male and female volleyball players in formative stages.

  20. Seasonal player wellness and its longitudinal association with internal training load: study in elite volleyball.

    Science.gov (United States)

    Clemente, Filipe M; Mendes, Bruno; Palao, José M; Silvério, André; Carriço, Sandro; Calvete, Francisco; Nakamura, Fábio Y

    2018-04-04

    Monitoring training load is critical to minimize the risk of overreaching, injury or illness. The purpose of this study was to assess the relationships and variance between perceived internal load and wellness status of elite male volleyball. Thirteen elite volleyball players were studied during a full competitive season (nine months, 237 training sessions and 37 official matches). Perceived exertion, muscle soreness, stress, fatigue and sleep quality levels were daily measured using session RPE and the Hopper Questionnaire. Moderate-to-large correlations were found between weekly training load and perceived status of muscle soreness, fatigue and stress. Stronger correlations were found between weekly training loads than daily training load. Significant greater stress levels in match days than in training were found. No correlations between load and wellness were not found in the last month when players perceived higher levels of stress due to the competition. The analysis of the weekly training load had a higher relationship with players' wellness status in pre-season and middle of the season. In the last part of the season (final matches for the title), despite of a decrease in perceived load of last month of the season, there was an increase stress and fatigue levels. These results suggest the importance of including the impact on the competition when elite athletes are monitored. The results show the monitoring tools used may help in to characterize the training process of teams and the player's acute and chronic responses.

  1. THE EFFECTS OF SIXWEEKS PROGRAM OF PLYOMETRIC TRENING ON VOLLEYBALL JUMPING

    Directory of Open Access Journals (Sweden)

    Vladan Milić

    2008-08-01

    Full Text Available With goal to examine effects of plyometric training program on development of jumping strength for volleyball players, it was organized an experimental research on pattern of 23 volleyball players from cadet team and 23 students from high-school. Guided by general principles for plyometric training, individual plans for training were made. For estimating the effects of sports training on development of jumping, eight variables were used. For needs of this research four tests are valid for estimation, jump in block with left and right leg and jump in spike with left and right leg. Experiment has been realized in the second part on conditional preparations, and lasted for six weeks with two or three trainings per week. Control group had physical education lessons at their schools twice a week. Data were processed by in variant, multivariate analysis and analysis of covariance. On the results of research and discussion we can say that the model of training we used for development of jumping as a basic factor in experimental group brought statistically bigger difference in improving jumping that it brought in control group.

  2. Close set in volleyball. Differences and discriminatory power of final game actions in formative stages

    Directory of Open Access Journals (Sweden)

    Dávila Romero, Carlos

    2012-01-01

    Full Text Available The aim of this study was to establish which final game actions discriminate final victories and defeats in women volleyball formative stages during ended sets, which are solved by regulation with a minimal advantage of two points. A total of 57 sets were analyzed in infantile category and 69 sets in cadet category during the national volleyball championship at school age (12-16, Valladolid 2008 and Huelva 2009. Statistics analysis shows differences between the condition of both the winner and the loser teams in sets in the positive attack in infantile category and in positive block and error in cadet category. Discriminative analysis, statistical test that determines those most significant game actions when establishing the differences existing between the winner and loser teams, shows how to predict victory and defeat in the ended sets regarding the positive attack, negative service and error in infantile category and positive block and error in cadet category. These ones suggest that during decisive set moments in both categories, either technical gestures control or errors which arise from a regulation infraction may predict their final performance.

  3. Sports training in volleyball youth sport centers in the Czech republic

    Directory of Open Access Journals (Sweden)

    Michal Lehnert

    2012-03-01

    Full Text Available BACKGROUND: Together with the increase of importance of sport as a social phenomenon importance of optimizing the system of sports training of talented athletes is growing. OBJECTIVES: The aim of this study was to obtain information on the activities of coaches, training process, and conditions under which they are realized in volleyball youth sports centers in the Czech Republic (SpS. METHODS: We have created a survey focused on six topical areas of sports training in volleyball. This paper deals with the analysis of areas "Coaches and their activities" and "training process". The questionnaire was sent to 18 coaches of male teams incorporated to SpS, 18 coaches responded (response rate 100%. RESULTS: We found a statistically significant relationship (rpb = 0.41; p < 0.05 between long-term performance and competences of coaches. The research shows that activity in particular SpS in most areas is consistent with current knowledge and trends in youth training. Reserves exist primarily in the number of coaches working with individual teams (in 13 cases only 1 coach and in regeneration. In some SpS a unified training strategy is missing and training process is not properly structured. CONCLUSIONS: The study allowed partial evaluation of conditions, quality and content of the training process in the SPS. The acquired knowledge can contribute to the improvement of SpS functioning.

  4. Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball

    Directory of Open Access Journals (Sweden)

    Giannopoulos Nikiforos

    2017-08-01

    Full Text Available This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2 and playing position (hitters vs. centers vs. opposites considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs.

  5. Impact of an Interdisciplinary Food, Nutrition and Health Education Program for adolescent Brazilian volleyball players

    Directory of Open Access Journals (Sweden)

    Natália Vilela Silva DANIEL

    Full Text Available ABSTRACT Objective: To evaluate the impact of an Interdisciplinary Food, Nutrition and Health Education Program on nutrition knowledge, intention to change eating behavior, and body dissatisfaction of adolescent volleyball players. Methods: The sample consisted of 10 female volleyball players from the juvenile category of the city of Santos, São Paulo, Brazil, who participated in a program with eight monthly meetings (one discussion group followed by six educational activities and one final discussion group for evaluation. Results: Nutrition knowledge, body perception, intention to change eating behavior, eating attitudes and practices were investigated using questionnaires and discussion groups before and after the athletes' participation in ludic activities designed to address nutrition strategies for athletic performance and healthy eating, and how to deal with pressure for results and self-image. Nutrition knowledge improved from 57.0%±9.9 to 63.0%±11.8 (p=0.03 of correct answers. The mean body distortion score did not change (70.0±14.9 versus 76.5±22.4, p=0.235. Six athletes advanced in their intention to change eating behavior. Positive food practices were reported during the program and the identified discourses indicated the intention of changing the daily eating habits in the future. Conclusion: The program had a positive impact on nutrition knowledge and intention of changing eating behavior; however, for other issues, especially involving emotional aspects, further interventions should be planned.

  6. Response Time, Visual Search Strategy, and Anticipatory Skills in Volleyball Players

    Directory of Open Access Journals (Sweden)

    Alessandro Piras

    2014-01-01

    Full Text Available This paper aimed at comparing expert and novice volleyball players in a visuomotor task using realistic stimuli. Videos of a volleyball setter performing offensive action were presented to participants, while their eye movements were recorded by a head-mounted video based eye tracker. Participants were asked to foresee the direction (forward or backward of the setter’s toss by pressing one of two keys. Key-press response time, response accuracy, and gaze behaviour were measured from the first frame showing the setter’s hand-ball contact to the button pressed by the participants. Experts were faster and more accurate in predicting the direction of the setting than novices, showing accurate predictions when they used a search strategy involving fewer fixations of longer duration, as well as spending less time in fixating all display areas from which they extract critical information for the judgment. These results are consistent with the view that superior performance in experts is due to their ability to efficiently encode domain-specific information that is relevant to the task.

  7. The effect of assisted jumping on vertical jump height in high-performance volleyball players.

    Science.gov (United States)

    Sheppard, Jeremy M; Dingley, Andrew A; Janssen, Ina; Spratford, Wayne; Chapman, Dale W; Newton, Robert U

    2011-01-01

    Assisted jumping may be useful in training higher concentric movement speed in jumping, thereby potentially increasing the jumping abilities of athletes. The purpose of this study was to evaluate the effects of assisted jump training on counter-movement vertical jump (CMVJ) and spike jump (SPJ) ability in a group of elite male volleyball players. Seven junior national team volleyball players (18.0±1.0 yrs, 200.4±6.7 cm, and 84.0±7.2 kg) participated in this within-subjects cross-over counter-balanced training study. Assisted training involved 3 sessions per week of CMVJ training with 10 kg of assistance, applied through use of a bungee system, whilst normal jump training involved equated volume of unassisted counter-movement vertical jumps. Training periods were 5 weeks duration, with a 3-week wash-out separating them. Prior to and at the conclusion of each training period jump testing for CMVJ and SPJ height was conducted. Assisted jump training resulted in gains of 2.7±0.7 cm (pSports Medicine Australia. All rights reserved.

  8. Oil sands tailings management project

    Energy Technology Data Exchange (ETDEWEB)

    Godwalt, C. [Alberta WaterSMART, Calgary, AB (Canada); Kotecha, P. [Suncor Energy Inc, Calgary, AB (Canada); Aumann, C. [Alberta Innovates - Technology Futures, Alberta Governement, AB (Canada)

    2010-11-15

    The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

  9. Oil sands tailings management project

    International Nuclear Information System (INIS)

    Godwalt, C.; Kotecha, P.; Aumann, C.

    2010-11-01

    The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

  10. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Directory of Open Access Journals (Sweden)

    Bahri Gjinovci, Kemal Idrizovic, Ognjen Uljevic, Damir Sekulic

    2017-12-01

    Full Text Available There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg, who participated in plyometric- (n = 21, or skill-based-conditioning-program (n = 20. Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM, countermovement jump (CMJ, standing broad jump (SBJ, medicine ball throw, (MBT and 20-m sprint (S20M. All tests were assessed at the study baseline (pre- and at the end of the 12-week programs (post-testing. Two-way ANOVA for repeated measurements showed significant (p<0.05 “Group x Time” effects for all variables but body-height. Plyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes, and improved their performance in S20M (moderate ES; 8%, MBT (very large ES; 25%, CMJ (large ES; 27%, and SBJ (moderate ES; 8%. Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%, SBJ (small ES; 3%, and MBT (large ES; 9%. The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  11. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-01-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pvolleyball players. Future studies should evaluate differential program effects in less experienced and younger players. Key points Plyometric- and skill-based-conditioning resulted in improvements in jumping and throwing capacities, but plyometric training additionally induced positive changes in anthropometrics and sprint-capacity The changes induced by plyometric training were larger in magnitude than those achieved by skill-based conditioning. The higher intensity together with possibility of more accurate adjustment of training load in plyometric training are probably the most important determinant of such differential influence. It is likely that the skill-based conditioning program did not result in changes of higher magnitude because of the players’ familiarity with volleyball-related skills. PMID:29238253

  12. Stature and jumping height are required in female volleyball, but motor coordination is a key factor for future elite success.

    Science.gov (United States)

    Pion, Johan A; Fransen, Job; Deprez, Dieter N; Segers, Veerle I; Vaeyens, Roel; Philippaerts, Renaat M; Lenoir, Matthieu

    2015-06-01

    It was hypothesized that differences in anthropometry, physical performance, and motor coordination would be found between Belgian elite and sub-elite level female volleyball players using a retrospective analysis of test results gathered over a 5-year period. The test sample in this study consisted of 21 young female volleyball players (15.3 ± 1.5 years) who were selected to train at the Flemish Top Sports Academy for Volleyball in 2008. All players (elite, n = 13; sub-elite, n = 8) were included in the same talent development program, and the elite-level athletes were of a high to very high performance levels according to European competition level in 2013. Five multivariate analyses of variance were used. There was no significant effect of playing level on measures of anthropometry (F = 0.455, p = 0.718, (Equation is included in full-text article.)= 0.07), flexibility (F = 1.861, p = 0.188, (Equation is included in full-text article.)= 0.19), strength (F = 1.218, p = 0.355, (Equation is included in full-text article.)= 0.32); and speed and agility (F = 1.176, p = 0.350, (Equation is included in full-text article.)= 0.18). Multivariate analyses of variance revealed significant multivariate effects between playing levels for motor coordination (F = 3.470, p = 0.036, (Equation is included in full-text article.)= 0.59). A Mann-Whitney U test and a sequential discriminant analysis confirmed these results. Previous research revealed that stature and jump height are prerequisites for talent identification in female volleyball. In addition, the results show that motor coordination is an important factor in determining inclusion into the elite level in female volleyball.

  13. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning.

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-12-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pPlyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes), and improved their performance in S20M (moderate ES; 8%), MBT (very large ES; 25%), CMJ (large ES; 27%), and SBJ (moderate ES; 8%). Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%), SBJ (small ES; 3%), and MBT (large ES; 9%). The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  14. RELATION BETWEEN LATENT SPECIFIC MOTOR ABILITIES AND SITUATION MOTOR SKILLS WITH VOLLEYBALL PLAYERS AGED FROM 16 TO 17

    Directory of Open Access Journals (Sweden)

    Rabit Veseli

    2015-05-01

    Full Text Available The game of volleyball with its dynamic character is present in the world of the sport with permanent development and growing popularity and fans. Volleyball is part of a pollystructural complex sports activities. It is performed on a ground of a relatively small size (18 x 9 meters and is a kind of game that requires of players a high level of advanced motoric abilities (speed, strength, endurance, a fast rate of visual reaction, explosivity, as well as specific motoric skills (precision etc.. Scientific conclusion as well as the growing number of conducted researches in the very game, have a real contribution to its modern development and level of popularity. Situation-motoric skills make a significant dimension in the structure of volleyball game. The subject of the research is specific-motoric abilities and situation-motoric skills of 52 volleyball players aged from 16 to 17. The basic goal of the research is to establish the effect of specific-motoric abilities on situation-motoric skills of volleyball players in latent space. In order to assess the specific-motoric abilities 9 tests are used, and to assess the situation-motoric skills 3 precision tests are used. The results obtained from the 12 applied tests are worked out through the basic statistic parameters. Through component factor analysis 3 latent specific-motoric dimensions are isolated as well as one situation-motoric dimension. By regressive analysis there is established a low but statistically significant relation between the criterion and predictor latent dimensions. That confirms the dependence and relation between the specific-motoric abilities and situation-motoric skills. Researches in the fi eld of similar questions have been conducted by the following authors: Jurko et al., 2013 and Nešić, et al., 2011.

  15. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  16. The Effect of Submaximal Exercise Preceded by Single Whole-Body Cryotherapy on the Markers of Oxidative Stress and Inflammation in Blood of Volleyball Players

    OpenAIRE

    Mila-Kierzenkowska, Celestyna; Jurecka, Alicja; Woźniak, Alina; Szpinda, Michał; Augustyńska, Beata; Woźniak, Bartosz

    2013-01-01

    The aim of the study was to determine the effect of single whole-body cryotherapy (WBC) session applied prior to submaximal exercise on the activity of antioxidant enzymes, the concentration of lipid peroxidation products, total oxidative status, and the level of cytokines in blood of volleyball players. The study group consisted of 18 male professional volleyball players, who were subjected to extremely cold air (−130°C) prior to exercise performed on cycloergometer. Blood samples were taken...

  17. Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old

    Directory of Open Access Journals (Sweden)

    Oleg Shevchenko

    2016-04-01

    Full Text Available Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experience of sportsmen is 3–4 years. The analysis of scientifically-methodical literature, pedagogical testing, pedagogical experiment, methods of mathematical statistics were carried out. Results: the analyzed level of high-speed and high-speed and power abilities of volleyball players. Conclusions: the results had reliable changes (t=2,2–2,4 at р<0,05 of the level of high-speed and high-speed and power abilities of volleyball players of 12–13years old in the experimental group at the end of the experiment, except run on 30 m that demonstrates a positive influence of application of special exercises in the educational-training process.

  18. High-Intensity Training Improves Exercise Performance in Elite Women Volleyball Players During a Competitive Season.

    Science.gov (United States)

    Purkhús, Elisabeth; Krustrup, Peter; Mohr, Magni

    2016-11-01

    Purkhús, E, Krustrup, P, and Mohr, M. High-intensity training improves exercise performance in elite women volleyball players during a competitive season. J Strength Cond Res 30(11): 3066-3072, 2016-Elite women volleyball players (n = 25; mean ± SD: age, 19 ± 5 years; height, 171 ± 7 cm; weight, 63 ± 10 kg) volunteered to participate in the study. They were randomized into a high-intensity training (HIT; n = 13) group and a control (CON; n = 12) group. In addition to the normal team training and games, HIT performed 6-10 × 30-seconds all-out running intervals separated by 3-minute recovery periods 3 times per week during a 4-week in-season period whereas CON only completed the team training sessions and games. Preintervention and postintervention, all players completed the arrowhead agility test (AAT), a repeated sprint test (RST; 5 × 30 meters separated by 25 seconds of recovery), and the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) followed by a-10 minute rest period and the Yo-Yo IR1 test. Mean running distance during HIT in week 1 was 152 ± 4 m and increased (p ≤ 0.05) by 4.6% (159 ± 3 m) in week 4. The AAT performance improved (p ≤ 0.05) by 2.3% (18.87 ± 0.97-18.44 ± 1.06 seconds) and RST by 4.3% postintervention in the HIT group only. Baseline RST fatigue index was 7.0 ± 2.9 and 6.2 ± 5.0% in HIT and CON, respectively, but was lowered (p ≤ 0.05) to 2.7 ± 3.0% posttraining in HIT and remained unaltered in CON (5.5 ± 5.0%). In HIT, Yo-Yo IR2 and Yo-Yo IR1 performance improved by 12.6 and 18.3% postintervention, respectively, with greater (p ≤ 0.05) Yo-yo IR1 change scores than in CON. In conclusion, additional high-intensity in-season training performed as interval running improved agility, repeated sprint ability, and high-intensity intermittent exercise performance in elite women volleyball players.

  19. Sports benefits and the importance of muscle strength treinability in prepubertal volleyball athletes

    Directory of Open Access Journals (Sweden)

    Flávia Meyer

    2005-12-01

    Full Text Available The purpose of this review was to investigate the main benefits of sports and the importance and treinability muscle strenght in prepubescent volleyball athletes. Brazilian children are participating in competitive sports due to the increase of volleyball popularity. According to the literature reviewed, it seems that physical training is beneficial to bone tissue and tends to estimulate growth in height to the genetic limits. The main goal of children volleyball trainig is to improve basic technique and tatics and also to discover new talents. Young athletes need to be strong, fast, flexible and agile to achieve success. Strength training is indicated as an important complement to specific sports training of young athletes, due to improvement of muscle coordination and motor skills in competitive and recreational activities and to a decrease of joint overload and risk of injury. RESUMO O objetivo desta revisão foi investigar os principais benefícios do esporte e a importância e treinabilidade da força muscular de crianças pré-púberes atletas de voleibol. Com o aumento da popularidade do voleibol no Brasil, as crianças estão participando mais de competições esportivas. Conforme a literatura revisada, parece que o treinamento físico moderado é benéfico para o tecido ósseo e estimula o crescimento em estatura, até atingir a estatura geneticamente determinada. O principal objetivo do treinamento de voleibol para crianças é desenvolver as técnicas e as táticas básicas e detectar talentos esportivos. Para os jovens atletas obterem sucesso esportivo são necessárias qualidades físicas como força, velocidade, flexibilidade e agilidade. O treinamento de força muscular é indicado como auxiliar do treinamento esportivo para crianças atletas, melhorando a coordenação muscular e o desempenho motor nas atividades esportivas competitivas e recreacionais e diminuindo as sobrecargas articulares e o risco de lesões.

  20. Modelling offshore sand wave evolution

    NARCIS (Netherlands)

    Nemeth, Attila; Hulscher, Suzanne J.M.H.; van Damme, Rudolf M.J.

    2007-01-01

    We present a two-dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of offshore sand waves. The model contains the 2DV shallow water equations, with a free water surface and a general bed load formula. The water movement is coupled to the sediment transport

  1. Rheology of oil sands slurries

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R.; Zhou, J. [Alberta Research Council, Edmonton, AB (Canada). Mineral Oil Sands Unit; Wallace, D. [Dean Wallace Consulting Inc., Beaumont, AB (Canada)

    2006-07-01

    This study focused on integrating rheology and colloid science to improve recovery of bitumen in surface mined oil sands. Factors that influence recovery, such as conditions of particle interaction, solids concentration and shear rate, were reviewed. In an effort to understand the rheological behaviour of clay-in-water suspensions, an elaborate procedure was developed to separate an inter-bedded clay layer from a site at Albian Sands Energy Inc. The variables were water chemistry, solids concentration, and shear rate. The research study was conducted at the Alberta Research Council with the support of the CONRAD Extraction Group. A controlled stress rheometer was used to provide the quantitative evaluations of the clay slurry properties. The research results indicate that the viscoelastic properties of the slurry are highly influenced by the shear history of the slurry, solids content, calcium concentration, and sample aging. Shear thinning behaviour was observed in all slurry samples, but the slurry viscosity increased with test time for a given shear rate. In order to classify the slurries, a method was developed to distinguish the gel strength. The slurries were then classified into 3 distinct patterns, including no gel, weak gel and strong gel. The evolution of the experimental protocols were described along with the current stability maps that correlate the domains of the gel strength according to the solids concentration, calcium ion content, and shear rate. It was concluded that the rheological properties of oil sands slurries influence bitumen recovery in commercial surface-mined oil sands operations. tabs., figs.

  2. Geology on a Sand Budget

    Science.gov (United States)

    Kane, Jacqueline

    2004-01-01

    Earth science teachers know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, to use the models for only a few class periods. To avoid emptying an already limited science budget, the author states that teachers can use a simple alternative to the expensive 3-D models--sand. She…

  3. Somatotype and body composition of volleyball players and untrained female students – reference group for comparison in sport

    Directory of Open Access Journals (Sweden)

    Pastuszak Anna

    2016-12-01

    Full Text Available There is substantial evidence that somatotype and success in sport and physical performance are positively related. Existing somatotype data on athletes are useful as guidelines for sport selection and choice of training appropriate to the enhancement of desired somatotype characteristics. Updated somatotype data from non-athlete reference groups complement comparative analysis applied in assessing the effects of the training process and selection. The aim of this study was to determine the somatotype of untrained girls studying at Warsaw University of Technology in 2011, in order to create a current reference group for comparison, and to investigate the difference in body build of female volleyball players compared with the non-athlete group. Twelve Second Division female volleyball players (age 21.6±1.5 years, body height 177.3±6.2 cm, body mass 71.0±6.5 kg, training experience 8.4±3.4 years and 150 female untrained students of the University of Technology in Warsaw (age 20.0±6.4 years, body height 166.5±6.4 cm, body mass 59.7±8.4 kg participated in a study carried out in 2011. Somatotype was determined using the Heath-Carter method. The volleyball players were a little older and were significantly taller and heavier than female students (p<0.05. Significant differences between the groups were found in breadth of the elbow, breadth of the wrist, biacromial diameter, arm circumference and crus circumference (p<0.05. The mean somatotype of the volleyball players was 4.5-3.4-2.8. (4.5±1.0-3.4±1.2-2.8±1.3, whilst that of the untrained students was 5.1-3.6-2.8. (5.1±1.4-3.6±1.1-2.8±1.3; the groups did not differ significantly in somatotype. The groups were significantly different in body composition (F [kg] and LBM [kg], as estimated by BIA and anthropometric methods (p<0.05. No differences were observed between the groups in the skinfolds. Morphological characteristics of the female volleyball players depended on the competition level

  4. Collaboration rules.

    Science.gov (United States)

    Evans, Philip; Wolf, Bob

    2005-01-01

    Corporate leaders seeking to boost growth, learning, and innovation may find the answer in a surprising place: the Linux open-source software community. Linux is developed by an essentially volunteer, self-organizing community of thousands of programmers. Most leaders would sell their grandmothers for workforces that collaborate as efficiently, frictionlessly, and creatively as the self-styled Linux hackers. But Linux is software, and software is hardly a model for mainstream business. The authors have, nonetheless, found surprising parallels between the anarchistic, caffeinated, hirsute world of Linux hackers and the disciplined, tea-sipping, clean-cut world of Toyota engineering. Specifically, Toyota and Linux operate by rules that blend the self-organizing advantages of markets with the low transaction costs of hierarchies. In place of markets' cash and contracts and hierarchies' authority are rules about how individuals and groups work together (with rigorous discipline); how they communicate (widely and with granularity); and how leaders guide them toward a common goal (through example). Those rules, augmented by simple communication technologies and a lack of legal barriers to sharing information, create rich common knowledge, the ability to organize teams modularly, extraordinary motivation, and high levels of trust, which radically lowers transaction costs. Low transaction costs, in turn, make it profitable for organizations to perform more and smaller transactions--and so increase the pace and flexibility typical of high-performance organizations. Once the system achieves critical mass, it feeds on itself. The larger the system, the more broadly shared the knowledge, language, and work style. The greater individuals' reputational capital, the louder the applause and the stronger the motivation. The success of Linux is evidence of the power of that virtuous circle. Toyota's success is evidence that it is also powerful in conventional companies.

  5. Passion and coping: relationships with changes in burnout and goal attainment in collegiate volleyball players.

    Science.gov (United States)

    Schellenberg, Benjamin J I; Gaudreau, Patrick; Crocker, Peter R E

    2013-06-01

    This study examined the relationship between harmonious and obsessive passion and coping, and assessed whether coping mediated the relationship between passion types and changes in burnout and goal attainment. College- and university-level volleyball players (N = 421) completed measures of passion, coping, burnout, and goal attainment at the start and end of a season. Results of structural equation modeling, using a true latent change approach, supported a model whereby types of passion were indirectly related to changes in burnout and goal attainment via coping. Harmonious passion was positively related to task-oriented coping which, in turn, was positively associated with change in goal attainment. Obsessive passion was positively associated with disengagement-oriented coping which, in turn, was positively and negatively associated with changes in burnout and goal attainment, respectively. This study identifies coping as a reason why passionate athletes may experience changes in burnout and goal attainment over the course of a season.

  6. Technical and tactical performance indicators based on the outcome of the set in the school volleyball

    Directory of Open Access Journals (Sweden)

    Yago Pessoa da Costa

    2017-09-01

    Full Text Available The aim of the study was to identify and compare the technical and tactical performance indicators based on the outcome of the set in the school female volleyball. The study included 110 athletes, aged between 12 and 14 years, belonging to 11 teams. Fifty-eight sets of 28 games were filmed and 7194 actions, 2830 serves, 2157 serve reception, 1358 passes and 1299 attacks were analyzed. Afterwards, the game sets were divided into winners and losers sets. Teams that won the sets had advantage at the serve reception, set and attack on error and excellence/point criteria (p< 0.05 and of serve, set and attack (p< 0.001. In conclusion, the winner’s sets were those with a better technical-tactical performance quantitatively and qualitatively.

  7. Group cohesion and starting status in successful and less successful elite volleyball teams.

    Science.gov (United States)

    Spink, K S

    1992-08-01

    The main purpose of this study was to examine the relationship between members' perceptions of group cohesion and starting status in elite volleyball teams. The results of the study revealed that the form of the cohesion-starting status relationship was moderated by the variable of success. The results for less successful teams revealed that differences did emerge between specific measures of cohesion endorsed by starters and non-starters. No such differences in cohesion emerged when the starters and non-starters on successful teams were compared. These results provide initial support for the suggestion that the most successful teams are the ones where the perceptions of cohesiveness by starters and non-starters are similar. A secondary purpose of the study was to determine whether those teams that were the most successful and similar in their members' perceptions of cohesiveness, were also the teams whose members have the most positive outcome expectancy. The results supported this prediction.

  8. Bench press training program with attached chains for female volleyball and basketball athletes.

    Science.gov (United States)

    Burnham, Timothy R; Ruud, Jason D; McGowan, Robert

    2010-02-01

    Attaching chains to barbells to increase strength and power has become popular for athletes; however, little scientific evidence supports this practice. The present purpose was to compare chain training to traditional training for the bench press. Women collegiate athletes in volleyball and basketball (N = 19) participated in a 16-session bench press program. They were matched into either a Traditional or a Chain training group by 1-repetition maximum (1RM). The Traditional group performed the bench press with conventional equipment, while the Chain group trained with attached chains (5% of weight). Analysis showed a significant increase in 1RM for both groups over 16 sessions, Traditional +11.8% and Chain +17.4%. The difference between the groups was not statistically significant, but suggests the women who trained with attached chains improved their bench press more than the Traditional group.

  9. Tidal dynamics in the sand motor lagoon

    NARCIS (Netherlands)

    De Vries, S.; Radermacher, M.; De Schipper, M.A.; Stive, M.J.F.

    2015-01-01

    The Sand Motor is a mega-nourishment characterized by a very large sand volume of around 20 million m3 placed along the Dutch coast. The Sand Motor is a pilot project to evaluate the performance of an alternative nourishment strategy with respect to different functions of the coastal system. Within

  10. Australian road rules

    Science.gov (United States)

    2009-02-01

    *These are national-level rules. Australian Road Rules - 2009 Version, Part 18, Division 1, Rule 300 "Use of Mobile Phones" describes restrictions of mobile phone use while driving. The rule basically states that drivers cannot make or receive calls ...

  11. Who jumps the highest? Anthropometric and physiological correlations of vertical jump in youth elite female volleyball players.

    Science.gov (United States)

    Nikolaidis, Pantelis T; Gkoudas, Konstantinos; Afonso, José; Clemente-Suarez, Vicente J; Knechtle, Beat; Kasabalis, Stavros; Kasabalis, Athanasios; Douda, Helen; Tokmakidis, Savvas; Torres-Luque, Gema

    2017-06-01

    The aim of the present study was to examine the relationship of vertical jump (Abalakov jump [AJ]) with anthropometric and physiological parameters in youth elite female volleyball players. Seventy-two selected volleyball players from the region of Athens (age 13.3±0.7 years, body mass 62.0±7.2 kg, height 171.5±5.7 cm, body fat 21.2±4.5%), classified into quartiles according to AJ performance (group A, 21.4-26.5 cm; group B, 26.8-29.9 cm; group C, 30.5-33.7 cm; group D, 33.8-45.9 cm), performed a series of physical fitness tests. AJ was correlated with anthropometric (age at peak height velocity [APHV]: r=0.38, Pvolleyball players that jumped the highest were those who matured later than others.

  12. CHANGES IN DEVELOPMENT OF EHPLOSIVE POWER OF LEGS UNDER THE INFLUENCE OF PLYOMETRIC TRAINING METHOD BY VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Vladan Milić

    2009-11-01

    Full Text Available With goal to examine effects of plyometric training program on development of jumping strength for volleyball players, it was organized an experimental research on pattern of 23 volleyball players from cadet team and 23 students from high-school. For needs of this research four tests are valid for estimation, jump in block with left and right leg and jump in spike with left and right leg. Experiment has been realized in the second part on conditional preparations, and lasted for six weeks with two or three trainings per week. Control group had physical education lessons at their schools twice a week. On the results of research and discussion we can say that the model of training we used for development of jumping as a basic factor in experimental group brought statistically bigger difference in improving jumping that it brought in control group.

  13. METHOD OF PROCESSING MONAZITE SAND

    Science.gov (United States)

    Welt, M.A.; Smutz, M.

    1958-08-26

    A process is described for recovering thorium, uranium, and rare earth values from monazite sand. The monazite sand is first digested with sulfuric acid and the resulting "monazite sulfate" solution is adjusted to a pH of between 0.4 and 3.0, and oxalate anions are added causing precipitation of the thorium and the rare earths as the oxalates. The oxalate precipitate is separated from the uranium containing supernatant solution, and is dried and calcined to the oxides. The thorium and rare earth oxides are then dissolved in nitric acid and the solution is contacted with tribntyl phosphate whereby an organic extract phase containing the cerium and thorium values is obtained, together with an aqueous raffinate containing the other rare earth values. The organic phase is then separated from the aqueous raffinate and the cerium and thorium are back extracted with an aqueous medium.

  14. Ultrasound assessment of the posterior circumflex humeral artery in elite volleyball players: Aneurysm prevalence, anatomy, branching pattern and vessel characteristics

    OpenAIRE

    van de Pol, Daan; Maas, Mario; Terpstra, Aart; Pannekoek-Hekman, Marja; Alaeikhanehshir, Sena; Kuijer, P. Paul F. M.; Planken, R. Nils

    2016-01-01

    Objectives To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players. Methods Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ?150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter. R...

  15. Training Load, Physical Performance, Biochemical Markers, and Psychological Stress During A Short Preparatory Period in Brazilian Elite Male Volleyball Players.

    Science.gov (United States)

    Horta, Thiago A G; Bara Filho, Maurício G; Coimbra, Danilo R; Miranda, R; Werneck, Francisco Z

    2017-12-11

    The aim of this study was to assess the relationship between training load (TL) and physical performance, biochemical markers, and psychological stress during a short preparatory period (PP) in Brazilian elite male volleyball players. Twelve volleyball players from a team competing in the Brazilian Men's Volleyball Super League were enrolled (26.9 ± 4.6 years). Countermovement Jump (CMJ), Creatine Kinase (CK), Testosterone (T), Cortisol (Cr), T/Cr ratio, and Recovery and Stress Questionnaire for Athletes (RESTQ-Sport) were collected at baseline, after 2, 4, and 6 week. TL was quantified daily using the Rating of Perceived Exertion (RPE). Differences were noted between Total Weekly TL (TWTL) (F3,33 = 50.907; p = 0.0001), CK (F3,33 = 16.157; p = 0.0001), and T (F3,33 = 3.283; p = 0.03). No differences were seen in CMJ (F3,33 = 1.821; p = 0.16), Cr (F3,33 = 2.409; p = 0.08), or T/Cr ratio (F3,33 = 1.527; p = 0.23). The RESTQ-Sport demonstrated differences between moments in Social Stress (F3,33 = 2.297; p = 0.04; Eta = 0.25), Success (F3,33 = 4.350; p = 0.01; Eta = 0.19), General Well-being (F3,33 = 4.465; p = 0.01; Eta = 0.36), and Injury (F3,33 = 2.792; p = 0.05; Eta = 0.62). The results showed a significant correlations of small to moderate magnitude between TWTL and CK (r = 0.32; p = 0.05). In conclusion, a short PP in volleyball leads to increased TL, CK level, and psychological stress. TL was related with the increase of CK, suggesting muscle damage without increased of physical performance.

  16. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Garcia R, G.; Ordonez R, E.; Ordonez R, En.

    2002-01-01

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO 4 ) and the alpha zirconium hydrogen phosphate (Zr(HPO 4 ) 2H 2 O) starting from sea sand in an easy and economic way. (Author)

  17. High prevalence of self-reported symptoms of digital ischemia in elite male volleyball players in the Netherlands: a cross-sectional national survey.

    Science.gov (United States)

    van de Pol, Daan; Kuijer, P Paul F M; Langenhorst, Ton; Maas, Mario

    2012-10-01

    In the past 3 years, 6 volleyball players with ischemic digits and small microemboli in the digital arteries of the dominant hand presented themselves in our hospital. These complaints were caused by an aneurysmatic dilation of the posterior circumflex humeral artery (PCHA) with distal occlusion and digital emboli in the isolateral limb. All were elite male volleyball players active in the national top league. Little is known about the exact symptoms associated with PCHA pathological lesions with digital emboli (PCHAP with DE) and its prevalence in elite volleyball players. If vascular injury can be identified at an early stage, thromboembolic complications and irreversible damage to the digits might be prevented. To assess the prevalence of symptoms that are consistent with digital ischemia and may be caused by PCHAP with DE in elite male volleyball players in the Netherlands. Cross-sectional study; Level of evidence, 3. A questionnaire survey was performed among elite volleyball players in the Dutch national top league and the Dutch beach volleyball team. The questionnaire was constructed using literature-based data on symptoms associated with PCHAP with DE, together with data retrieved from medical files. A total of 99 of the 107 athletes participated, with a response rate of 93%. The most frequently reported symptoms associated with PCHAP with DE were cold, blue, or pale digits in the dominant hand during or immediately after practice or competition. The prevalence of these symptoms ranged from 11% to 27%. The prevalence of cold digits during practice and competition was 27%. The prevalence of cold, blue, and pale digits during or immediately after practice and competition was 12%. An unexpectedly high percentage of elite volleyball players reported symptoms that are associated with PCHAP with DE in the dominant hand. Because these athletes are considered potentially at risk for developing critical digital ischemia, further analysis of the presence of digital

  18. Salivary cortisol, alpha-amylase and immunoglobulin a responses to a morning session of basketball or volleyball training in boys aged 14-18 years.

    Science.gov (United States)

    Bruzda-Zwiech, A; Konieczka, M; Hilt, A; Daszkowska, M; Grzegorczyk, J; Szczepańska, J

    2017-01-01

    This study investigates whether a single session of routine morning basketball or volleyball training affects saliva levels of cortisol, alpha-amylase (sAA) and secretory immunoglobulin A (sIgA) in boys aged 14–18 years. Twenty-nine boys who participate in basketball or volleyball training, recruited from the Marcin Gortat’s Athletic Championship School in Lodz, were enrolled in the study. The 90-minute routine exercise program included 15 minutes of warm-up followed by basketball or volleyball practice. Unstimulated saliva samples were collected prior to and immediately after the exercise, and were analysed using ELISA. One training session resulted in a significant increase of sAA concentration in all participants, as well as in the volleyball and basketball subgroups (p=0.00022; p=0.0029; p=0.0011; respectively). Post-exercise cortisol levels were significantly lower than pre-exercise levels (p=0.00002) throughout the group, as well as in the volleyball and basketball subgroups (p=0.0048; p=0.0019; p=0.0048; respectively). The exercise protocol did not significantly affect sIgA level, either in the whole examined group or the volleyball subgroup, however a weak significant increase of sIgA was observed in the basketball subgroup (p=0.046). The routine morning training session comprising a warm-up followed by basketball or volleyball practice seems to activate the sympatho-adrenal-medullary system, with a subsequent increase of alpha-amylase, but does not affect oral immunity in 14-18-year-old boys.

  19. Variables that Predict Serve Efficacy in Elite Men’s Volleyball with Different Quality of Opposition Sets

    Science.gov (United States)

    Valhondo, Álvaro; Fernández-Echeverría, Carmen; González-Silva, Jara; Claver, Fernando; Moreno, M. Perla

    2018-01-01

    Abstract The objective of this study was to determine the variables that predicted serve efficacy in elite men’s volleyball, in sets with different quality of opposition. 3292 serve actions were analysed, of which 2254 were carried out in high quality of opposition sets and 1038 actions were in low quality of opposition sets, corresponding to a total of 24 matches played during the Men’s European Volleyball Championships held in 2011. The independent variables considered in this study were the serve zone, serve type, serving player, serve direction, reception zone, receiving player and reception type; the dependent variable was serve efficacy and the situational variable was quality of opposition sets. The variables that acted as predictors in both high and low quality of opposition sets were the serving player, reception zone and reception type. The serve type variable only acted as a predictor in high quality of opposition sets, while the serve zone variable only acted as a predictor in low quality of opposition sets. These results may provide important guidance in men’s volleyball training processes. PMID:29599869

  20. Visual- spatial capacity: gender and sport differences in young volleyball and tennis athletes and non-athletes.

    Science.gov (United States)

    Notarnicola, Angela; Maccagnano, Giuseppe; Pesce, Vito; Tafuri, Silvio; Novielli, Grazia; Moretti, Biagio

    2014-01-21

    In the general population visual-spatial ability is better in males, due to the influence of biological and socio-cultural factors. We know that sport activity improves motor skills. The aim of this work is to determine if these gender differences exist in young athletes. The orientation test described by Terzi and standardized by Cesaroni, used to measure spatial ability, was carried out on 60 volleyball or 60 tennis athletes as well as on 60 non-sporting subjects. The data analysis revealed a worse performance for non-athletes in comparison with athletes in both components of test (p volleyball and tennis groups. As far as gender comparison is concerned, as expected in the non- sport group the males presented better values (p volleyball and tennis the specific training is able to develop spatial ability. Besides, boys and girls have similar performance demands and training experience. It appears that this specific training could be responsible for modifying gender differences in performance of spatial ability during adolescence.

  1. Training volume and body composition as risk factors for developing jumper's knee among young elite volleyball players.

    Science.gov (United States)

    Visnes, H; Bahr, R

    2013-10-01

    Training volume and body composition have been suggested as risk factors for jumper's knee among athletic youth, but research is lacking. The aim of this 4-year prospective cohort study was to examine the relationship between training and competition load, body composition, and risk for developing jumper's knee. Participants are elite volleyball players, aged 16-18 years. Training and competition load was recorded continuously and body composition semiannually. Jumper's knee was diagnosed on a standardized clinical examination. We recruited 141 healthy students (69 males and 72 females), and 28 developed jumper's knee (22 boys and six girls). In a multivariate analyses, boys had three to four times higher risk compared with girls. Volleyball training had an odds ratio (OR) 1.72 (1.18-2.53) for every extra hour trained, and match exposure was the strongest sports-related predictor for developing jumper's knee with an OR of 3.88 (1.80-8.40) for every extra set played per week. We did not detect any significant differences between the groups in body composition at the time of inclusion or in the change of body composition during the study period. Conclusion, male gender, a high volume of volleyball training and match exposure were risk factors for developing jumper's knee. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. The Effects of 3-Month Skill-Based and Plyometric Conditioning on Fitness Parameters in Junior Female Volleyball Players.

    Science.gov (United States)

    Idrizovic, Kemal; Gjinovci, Bahri; Sekulic, Damir; Uljevic, Ognjen; João, Paulo Vicente; Spasic, Miodrag; Sattler, Tine

    2018-02-24

    This study compared the effects of skill-based and plyometric conditioning (both performed in addition to regular volleyball training twice a week for 12 wk) on fitness parameters in female junior volleyball players. The participants [n = 47; age: 16.6 (0.6) y; mass: 59.4 (8.1) kg; height: 175.1 (3.0) cm] were randomized into a plyometric (n = 13), a skill-based (n = 17), and a control (n = 17) groups. The variables included body height, body mass, calf girth, calf skinfold, corrected calf girth, countermovement jump, 20-m-sprint, medicine ball toss, and sit-and-reach test. Two-way analysis of variance (time × group) effects for time were significant (P plyometric group, and sit-and-reach (η 2  = .35; large ES), with greater gains in plyometric and skill-based groups. The magnitude-based inference indicated positive changes in 1) medicine ball toss and countermovement jump for all groups; 2) sit-and-reach for the plyometric and skill-based groups; and 3) 20-m sprint, calf girth, calf skinfold, and corrected calf girth for plyometric group only. Selected variables can be improved by adding 2 plyometric training sessions throughout the period of 12 weeks. Additional skill-based conditioning did not contribute to improvement in the studied variables compared with regular volleyball training.

  3. Isokinetic knee strength qualities as predictors of jumping performance in high-level volleyball athletes: multiple regression approach.

    Science.gov (United States)

    Sattler, Tine; Sekulic, Damir; Spasic, Miodrag; Osmankac, Nedzad; Vicente João, Paulo; Dervisevic, Edvin; Hadzic, Vedran

    2016-01-01

    Previous investigations noted potential importance of isokinetic strength in rapid muscular performances, such as jumping. This study aimed to identify the influence of isokinetic-knee-strength on specific jumping performance in volleyball. The secondary aim of the study was to evaluate reliability and validity of the two volleyball-specific jumping tests. The sample comprised 67 female (21.96±3.79 years; 68.26±8.52 kg; 174.43±6.85 cm) and 99 male (23.62±5.27 years; 84.83±10.37 kg; 189.01±7.21 cm) high- volleyball players who competed in 1st and 2nd National Division. Subjects were randomly divided into validation (N.=55 and 33 for males and females, respectively) and cross-validation subsamples (N.=54 and 34 for males and females, respectively). Set of predictors included isokinetic tests, to evaluate the eccentric and concentric strength capacities of the knee extensors, and flexors for dominant and non-dominant leg. The main outcome measure for the isokinetic testing was peak torque (PT) which was later normalized for body mass and expressed as PT/Kg. Block-jump and spike-jump performances were measured over three trials, and observed as criteria. Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between and t-test differences between observed and predicted scores; and Bland Altman graphics. Jumping tests were found to be reliable (spike jump: ICC of 0.79 and 0.86; block-jump: ICC of 0.86 and 0.90; for males and females, respectively), and their validity was confirmed by significant t-test differences between 1st vs. 2nd division players. Isokinetic variables were found to be significant predictors of jumping performance in females, but not among males. In females, the isokinetic-knee measures were shown to be stronger and more valid predictors of the block-jump (42% and 64% of the explained variance for validation and cross-validation subsample, respectively

  4. Special aspects of hemo-dynamic and reaction of erythrocytes in blood to standard physical load of different qualification female volleyball players

    Directory of Open Access Journals (Sweden)

    S. L. Popel’

    2017-10-01

    Full Text Available Purpose: to study the aspects of organism’s cardio-hemo-dynamic and blood erythrocytes reaction of female volleyball players to standard physical load. Material: with functional methods we studied cardio-hemo-dynamic and with the help of scanning electronic microscopy - erythrocytes’ structure in 18 female volleyball players of different qualification (age - 22.0±0.60 years. Results: it was found that maximal physical load causes substantial changes in cardio-hemo-dynamic, which depend on female volleyball players’ qualification. These changes have intrinsic to them type of blood circulation system reacting, which is manifested in the following: appropriate changes of some indicators; natural changes of periphery blood erythrocytes. In the article possible mechanisms of realization of female volleyball players’ organism’s typological features, depending on blood circulation type and erythrocytes’ conformation, are discussed. Conclusions: In relaxed state all female volleyball players have non-uniform cardio-hemo-dynamic of blood circulation. With hyper-dynamic blood circulation type, higher indicators of strike and minute blood volume were observed. With hypo-kinetic blood circulation type the opposite picture was observed: indicators of strike and minute blood volume, heart index, load on cardio-vascular system in different periods of day were low.

  5. Application of Self Cleaning Rapid Sand Filter in Water Treatment

    Directory of Open Access Journals (Sweden)

    Ali Reza Rahmani

    2005-08-01

    Full Text Available Rapid sand filter is one of the most important units in the water treatment plants. It has some difficulties in operation such as backwashing. For the solving of this problem a rapid sand filter has designed and built with the self-cleaning backwashing system. This system consist of 3 main constituents; one galvanized siphon and two galvanized steel tanks. One of them is used for filtration and the other used for the storage of filtrated water in elevation for backwashing the system. Water enter from upside of the filter through the inlet pipe, and collected from the under drainage pipe. Then filter water conduct to the storage tank and exit from outlet pipe. In the beginning, the head loss was low, but because of bed clogging by suspended solids, it increases gradually to the designed head loss (1.2m. Then the system is outed of the service automatically and the backwash is began. The main data for the design of system selected from the hydraulic rules of siphons and rapid sand filter criteria. After essential calculations it was constructed and was started operation. For the hydraulic studies a known volume of storage tank was selected and the time needed for the fill (in filtration stage and empty (in backwash stage of water volume with volumetric method were measured. In hydraulic studies the filter surface rate (SOR was selected about 5-7.5m3/m2/hr (1.39-2.08 lit/sec and the flow of water in siphon, during the backwashing was measured 8.7 lit/sec. It can be seen that the siphon passes 4-6 times the inlet raw water thus a negative pressure will created in the siphon which causes the water above the sand bed to be discharged automatically and rinse water from elevated tank flow under the sand bed and back wash it. So according to this study self cleaning rapid sand filter is very useful for water filtration, especially in small population community. The construction of system is rapid, simple and economic.

  6. Studies in Phlebotomine Sand Flies.

    Science.gov (United States)

    1982-06-30

    Reporte de dos casos de [a ology of a sand fly, P/mlebolomu’,s diabolicuw Hall. in forma anergica difusa. Der matol. Rev. Mex. southwestern -Texas...Contribuiin al estudio de los Phmle- CDC, Veterinary Public Health Notes. USDHEW. bwmwnn de Costa Rica (Diptera, Psychodidae). Tesis. CDC. October. pp. 6- 7...janeiron R. j. 195 pp. the Unrited States (D1)pre ra: Psscfirdidae). j. Ortiz, 1. 1965a. Contribuci~in a! estudio tie los flebor- Partrsirtrl. 30:274-275

  7. Effects of Caffeine on Countermovement-Jump Performance Variables in Elite Male Volleyball Players.

    Science.gov (United States)

    Zbinden-Foncea, Hermann; Rada, Isabel; Gomez, Jesus; Kokaly, Marco; Stellingwerff, Trent; Deldicque, Louise; Peñailillo, Luis

    2018-02-01

    To examine the effects of a moderate dose of caffeine in elite male volleyball players on countermovement-jump (CMJ) performance, as well as temporal concentric- and eccentric-phase effects. Ten elite male volleyball players took part in 2 experimental days via a randomized crossover trial 1 wk apart in which they ingested either 5 mg/kg of caffeine or a placebo in double-blind fashion. Heart rate and blood pressure were measured at rest and 60 min postingestion. Afterward, subjects also performed 3 CMJ trials 60 min postingestion, of which the average was used for further analysis. They filled out a questionnaire on possible side effects 24 h posttrial. Caffeine intake, compared with placebo, increased CMJ peak concentric force (6.5% ± 6.4%; P = .01), peak power (16.2% ± 8.3%; P < .01), flight time (5.3% ± 3.4%; P < .01), velocity at peak power (10.6% ± 8.0%; P < .01), peak displacement (10.8% ± 6.5%; P < .01), peak velocity (12.6% ± 7.4%; P < .01), peak acceleration (13.5% ± 8.5%; P < .01), and the force developed at peak power (6.0% ± 4.0%; P < .01) and reduced the time between peak power and peak force (16.7% ± 21.6%, P = .04). Caffeine increased diastolic blood pressure by 13.0% ± 8.9% (P < .05), whereas no adverse side effects were found. The ingestion of 5 mg/kg of anhydrous caffeine improves overall CMJ performance without inducing side effects.

  8. Galveston Island, Texas, Sand Management Strategies

    Science.gov (United States)

    2016-07-01

    billion m3 of beach quality sand . However, Texas projects to date have not utilized these sources because of transportation costs. The lack of nearby...estimate that the San Luis Pass flood shoal contains approximately 11.8 million yd3 of beach quality sand . However, it is expected that if permits...a source of beach- quality sand . 2. Sand could be intercepted before it reaches the present dry beach. ERDC/CHL TR-16-13 55 3. The volume of

  9. Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix

    Directory of Open Access Journals (Sweden)

    Sanjay Mundra

    2016-09-01

    Full Text Available The study investigates the use of crushed rock sand as viable alternative to Natural River sand that is being conventionally used as fine aggregate in cement concrete. Various mix designs were developed for different grades of concrete based on IS, ACI and British codes using Natural River sand and crushed rock sand. In each case, the cube compressive strength test, and beam flexure tests were conducted. The results of the study show that, the strength properties of concrete using crushed rock sand are nearly similar to the conventional concrete. The study has shown that crushed stone sand can be used as economic and readily available alternative to river sand and can therefore help to arrest the detrimental effects on the environment caused due to excessive mining of river sand.

  10. Competitive activity analysis in play-off stage of 'Wiener Stadtische' Serbian volleyball league for men in 2012/2013 season

    Directory of Open Access Journals (Sweden)

    Majstorović Nikola

    2015-01-01

    Full Text Available Sport is defined as an activity that involves competition, specific preparation for the competition, specific relationships and connections in that area of activity taken as a whole. Analysis of competitive activity is the basis for a rational approach to the planning, programming, implementation and evaluation of the effects of systematic training process. Subject to this study was to analyze competitive activities of volleyball players in the play-off stage of 'Wiener Statische' Serbian league in season 2012/2013. The aim of the research is to determine characteristics of the volleyball game structure in competitive activity, to determine the technical-tactical elements with a statistically significant contribution to the achievement of positive results in the competition and to perform certain conclusions, with the help of research results, regarding the design of the training process. Description of elements was performed in the research, the contents that describe competitive activity in men's volleyball were explored, and then comparative analysis of these elements was performed for different levels of team performance. We can conclude that, based on these results, there is a statistically significant difference between successful and less successful men volleyball teams in only three variables, namely: the efficiency coefficient of serve, efficiency coefficient of block, efficiency coefficient of attack. This data is absolutely correspond to considerations in practice, which is that these three elements directly bring a point in the field, and therefore by observing them we can determine the winner of the match, with the highest certainty. Other elements, though necessary may influence the final outcome in men's volleyball to a lesser extent. Data from this study should be used primarily for modeling volleyball players training, with the ultimate projection on training improvement and game efficiency increase.

  11. New guidelines are needed to manage heat stress in elite sports--The Fédération Internationale de Volleyball (FIVB) Heat Stress Monitoring Programme.

    Science.gov (United States)

    Bahr, Roald; Reeser, Jonathan C

    2012-09-01

    There seems to be a discrepancy between the available heat stress guidelines and the actual risk of heat-related illness among professional beach volleyball players competing under hot and humid conditions. To monitor heat stress and record cases of heat-related medical forfeits on the Swatch FIVB Beach Volleyball World Tour. The FIVB Heat Stress Monitoring Protocol covered events on the FIVB Beach Volleyball World Tour and FIVB Beach Volleyball World Championships during the 2009, 2010 and 2011 seasons (51 events, most of these double gender). The protocol consisted of (1) measuring the Wet Bulb Globe Temperature (WBGT) on centre court prior to the start of every match, and (2) recording any heat-related medical forfeits during the tournament. Data were collected during 48 of 51 events. There were nine events where the peak WBGT exceeded the US Navy Black flag conditions of >32.3°C and an additional two events where the peak WBGT exceeded 31°C, (meeting Red flag conditions.) In two events, the average WBGT equalled at least 31°C. One case of a medical forfeit related to heat stress was recorded over the 3-year surveillance period: an athlete whose fluid balance was compromised from a 3-day bout of acute gastroenteritis. The incidence of significant heat illness among athletes competing on the FIVB Beach Volleyball World Tour appears to be quite low, even though weather conditions frequently result in a WBGT index >32°C. Currently available guidelines appear to be inadequate to fully assess the risk of heat stress and too conservative to inform safety decisions in professional beach volleyball.

  12. A Comparison of Women’s Collegiate and Girls’ High School Volleyball Injury Data Collected Prospectively Over a 4-Year Period

    Science.gov (United States)

    Reeser, Jonathan C.; Gregory, Andrew; Berg, Richard L.; Comstock, R. Dawn

    2015-01-01

    Background: There is a relative paucity of research examining the sport-specific injury epidemiology of high school and collegiate volleyball athletes. Moreover, differences in study methodology frequently limit our ability to compare and contrast injury data collected from selected populations. Hypothesis: There are differences between the injury patterns characteristic of high school and collegiate female volleyball athletes. Study Design: Retrospective clinical review. Level of Evidence: Level 3. Methods: We statistically analyzed injury incidence and outcome data collected over a 4-year interval (2005-2006 to 2008-2009) by 2 similar injury surveillance systems, the National Collegiate Athletic Association’s Injury Surveillance System (NCAA ISS) and the High School Reporting Injuries Online (HS RIO). We compared diagnoses, anatomic distribution of injuries, mechanisms of injury, and time lost from training or competition between high school and collegiate volleyball athletes. Results: The overall volleyball-related injury rate was significantly greater among collegiate athletes than among high school athletes during both competition (injury rate ratio, 2.9; 95% CI, 2.5-3.4) and practice (injury rate ratio, 3.5; 95% CI, 3.1-3.9). Collegiate athletes had a higher rate of ankle sprain, knee injury, and shoulder injury. Concussions represented a relatively high percentage of injuries in both populations (5.0% of total NCAA ISS injuries vs 4.8% of total HS RIO injuries, respectively). Conclusion: The data suggest that although similar, there were distinct differences between the injury patterns of the 2 populations. Compared with high school volleyball players, collegiate athletes have a higher rate of acute time loss injury as well as overuse time loss injury (particularly patellar tendinosis). Concussions represented a significant and worrisome component of the injury pattern for both study populations. Clinical Relevance: The injury data suggest that important

  13. Construct validity and reliability of a checklist for volleyball serve analysis

    Directory of Open Access Journals (Sweden)

    Cicero Luciano Alves Costa

    2018-03-01

    Full Text Available This study aims to investigate the construct validity and reliability of the checklist for qualitative analysis of the overhand serve in Volleyball. Fifty-five male subjects aged 13-17 years participated in the study. The overhand serve was analyzed using the checklist proposed by Meira Junior (2003, which analyzes the pattern of serve movement in four phases: (I initial position, (II ball lifting, (III ball attacking, and (IV finalization. Construct validity was analyzed using confirmatory factorial analysis and reliability through the Cronbach’s alpha coefficient. The construct validity was supported by confirmatory factor analysis with the RMSEA results (0.037 [confidence interval 90% = 0.020-0.040], CFI (0.970 and TLI (0.950 indicating good fit of the model. In relation to reliability, Cronbach’s alpha coefficient was 0.661, being this value considered acceptable. Among the items on the checklist, ball lifting and attacking showed higher factor loadings, 0.69 and 0.99, respectively. In summary, the checklist for the qualitative analysis of the overhand serve of Meira Junior (2003 can be considered a valid and reliable instrument for use in research in the field of Sports Sciences.

  14. Difference in kinematical behavior between two landing tasks in male volleyball athletes

    Directory of Open Access Journals (Sweden)

    Glauber Ribeiro Pereira

    2010-09-01

    Full Text Available Anterior cruciate ligament (ACL injuries are common in sports. Studies investigating injury mechanisms have demonstrated that most injuries arise from landing tasks. Despite the demonstration of differences between male and female kinematics, there are no studies showing how males behave during different landing tasks. The objective of this study was to compare the angular and temporal kinematics of the lower limbs between two different landing tasks. Double leg and single leg landings were recorded in the frontal and sagittal plane in 15 male volleyball athletes by videogrammetry. Reduced hip and knee flexion and increased knee valgus were observed in the single leg landing task compared to the double leg landing task. No significant difference in landing time was observed between the two tasks. In conclusion, the results support the premise that lower limb kinematics change according to the task performed. Further studies are necessary to explore the impact of these kinematic differences on knee loading and to relate them to ACL injury mechanisms in men.

  15. How players exploit variability and regularity of game actions in female volleyball teams.

    Science.gov (United States)

    Ramos, Ana; Coutinho, Patrícia; Silva, Pedro; Davids, Keith; Mesquita, Isabel

    2017-05-01

    Variability analysis has been used to understand how competitive constraints shape different behaviours in team sports. In this study, we analysed and compared variability of tactical performance indices in players within complex I at two different competitive levels in volleyball. We also examined whether variability was influenced by set type and period. Eight matches from the 2012 Olympics competition and from the Portuguese national league in the 2014-2015 season were analysed (1496 rallies). Variability of setting conditions, attack zone, attack tempo and block opposition was assessed using Shannon entropy measures. Magnitude-based inferences were used to analyse the practical significance of compared values of selected variables. Results showed differences between elite and national teams for all variables, which were co-adapted to the competitive constraints of set type and set periods. Elite teams exploited system stability in setting conditions and block opposition, but greater unpredictability in zone and tempo of attack. These findings suggest that uncertainty in attacking actions was a key factor that could only be achieved with greater performance stability in other game actions. Data suggested how coaches could help setters develop the capacity to play at faster tempos, diversifying attack zones, especially at critical moments in competition.

  16. Mathematical modelling as a tool to assessment of loads in volleyball player's shoulder joint during spike.

    Science.gov (United States)

    Jurkojć, Jacek; Michnik, Robert; Czapla, Krzysztof

    2017-06-01

    This article deals with kinematic and kinetic conditions in volleyball attack and identifies loads in the shoulder joint. Joint angles and velocities of individual segments of upper limb were measured with the use of the motion capture system XSENS. Muscle forces and loads in skeletal system were calculated by means of mathematical model elaborated in AnyBody system. Spikes performed by players in the best and worst way were compared with each other. The relationships were found between reactions in shoulder joint and flexion/extension, abduction/adduction and rotation angles in the same joint and flexion/extension in the elbow joint. Reactions in shoulder joint varied from 591 N to 2001 N (in relation to body weight [BW] 83-328%). The analysis proved that hand velocity at the moment of the ball hit (which varied between 6.8 and 13.3 m s -1 ) influences on the value of reaction in joints, but positions of individual segments relative to each other are also crucial. It was also proved in objective way, that position of the upper limb during spike can be more or less harmful assuming that bigger reaction increases possibility of injury, what can be an indication for trainers and physiotherapists how to improve injury prevention.

  17. Study of service in young volleyball players, taking into account efficacy and role play

    Directory of Open Access Journals (Sweden)

    *Alexander Gil Arias, *M. Perla Moreno Arroyo, *Alberto Moreno Domínguez, **Luís García González, *Fernando Del Villar Álvarez

    2011-01-01

    Full Text Available The main objective of this study was to analyze the volleyball serve formative stages based on the function punch game player and receiver, and its effectiveness, and also establishing partnerships between these variables and gender. To this end, we analyzed a total of 1827 shares belonging to pull Spain Championship regional selections cadet class of 2005. The results show that both boys and girls guide to serve the ball to other players who are neither attackers-front, or underwriters, or releasing. However, the variable effectiveness, predominate in children serves to permit the construction of multiple attacks, while girls performed serves to limit the options of building the attack. In the inferential analysis, the gender variable is significantly associated with the three variables considered in the investigation, where the completion of the service by receptor-bombers and effectively services 1 and 0 are associated significantly and positively with male gender while carrying out the services from the opposite and the central and efficacy 3 and 4 are associated significantly and positively with the female gender.

  18. Selected elements of motivational impact on sport performance in professional volleyball teams

    Directory of Open Access Journals (Sweden)

    Tomasz Seweryniak

    2016-10-01

    Full Text Available The purpose of this study is to present techniques and means through which professional sport teams coaches may influence their players’ motivation. It includes analysis of present solutions used in practice and indicates directions for potential improvements. The conclusions of this study are based on a series of dedicated survey concerning various elements of motivational impact. The research was carried out among  polish coaches of professional men’s volleyball league. The studies of literature combined with practical experience, allowed the authors to present a set of elements of motivational impact, including motivating methods referring to different sources and forms of motivation. The results show that in the process of motivation coaches resort to both individual and collective techniques of influence. Motivational means declared to be used by respondents include: motivational speech, ongoing assessment of actions, raising voice,  using reward and punishment system,  code of honor and motivational recordings with own and opponent’s actions.

  19. Does framing the hot hand belief change decision-making behavior in volleyball?

    Science.gov (United States)

    Raab, Markus; MacMahon, Clare

    2015-06-01

    Previous discussions of the hot hand belief, wherein athletes believe that they have a greater chance of scoring after 2 or 3 hits (successes) compared with 2 or 3 misses, have focused on whether this is the case within game statistics. Researchers have argued that the perception of the hot hand in random sequences is a bias of the cognitive system. Yet most have failed to explore the impact of framing on the stability of the belief and the behavior based on it. The authors conducted 2 studies that manipulated the frame of a judgment task. In Study 1, framing was manipulated via instructions in a playmaker allocation paradigm in volleyball. In Study 2, the frame was manipulated by presenting videos for allocation decisions from either the actor or observer perspective. Both manipulations changed the hot hand belief and sequential choices. We found in both studies that the belief in continuation of positive or negative streaks is nonlinear and allocations to the same player after 3 successive hits are reduced. The authors argue that neither the hot hand belief nor hot hand behavior is stable, but rather, both are sensitive to decision frames. The results can inform coaches on the importance of how to provide information to athletes.

  20. Sand dune tracking from satellite laser altimetry

    Science.gov (United States)

    Dabboor, Mohammed

    Substantial problems arise from sand movement in arid and semi-arid countries. Sand poses a threat to infrastructure, agricultural and urban areas. These issues are caused by the encroachment of sand on roads and railway tracks, farmland, towns and villages, and airports, to name a few. Sand movement highly depends on geomorphology including vegetation cover, shape and height of the terrain, and grain size of the sand. However, wind direction and speed are the most important factors that affect efficient sand movement. The direction of the movement depends on the main direction of the wind, but it has been shown that a minimum wind speed is required, e.g. wind gusts, to initiate sand transport. This fact prevents a simple calculation of sand transport from conventional wind data as wind records rarely contain sub-minute intervals masking out any wind gusts. An alternative of predicting sand transport is the direct observation of sand advance by in situ measurements or via satellite. Until recently, satellite imagery was the only means to compare dune shape and position for predicting dune migration over several years. In 2003, the NASA laser altimetry mission ICESat became operational and monitors elevations over all surface types including sand dunes with an accuracy of about 10-20 cm. In this study, ICESat observations from repeat tracks (tracks overlapping eachother within 50 m) are used to derive sand dune advance and direction. The method employs a correlation of the elevation profiles over several dunes and was sucessfully validated with synthetic data. The accuracy of this method is 5 meters of dune advance. One of the most active areas exhibiting sand and dune movement is the area of the Arabian Peninsula. Approximately one-third of the Arabian Peninsula is covered by sand dunes. Different wind regimes (Shamal, Kaus) cause sand dune movement in the selected study area in the eastern part of the Arabian Peninsula between 20-25 degrees North and 45-55 degrees

  1. Submarine sand ridges and sand waves in the eastern part of the China Sea

    Science.gov (United States)

    Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

    2016-04-01

    Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

  2. Fuel options for oil sands

    International Nuclear Information System (INIS)

    Wise, T.

    2005-01-01

    This presentation examined fuel options in relation to oil sands production. Options include steam and hydrogen (H 2 ) for upgrading; natural gas by pipeline; bitumen; petroleum coke; and coal. Various cost drivers were also considered for each of the fuel options. It was noted that natural gas has high energy value but the capital cost is low, and that coke's energy value is very low but the capital cost is high. A chart forecasting energy prices was presented. The disposition of Western Canada's northern gas situation was presented. Issues concerning rail transportation for coal were considered. Environmental concerns were also examined. A chart of typical gas requirements for 75,000 B/D oil sands projects was presented. Issues concerning steam generation with gas and mining cogeneration with gas fuel and steam turbines were discussed, as well as cogeneration and H 2 with gas fuels and steam turbines. Various technology and fuel utility options were examined, along with details of equipment and processes. Boiler technologies were reviewed by type as well as fuel and steam quality and pressure. Charts of cogeneration with gas turbine and circulation fluid bed boilers were presented. Gasification processes were reviewed and a supply cost basis was examined. Cost drivers were ranked according to energy, operating considerations and capital investment. Results indicated that fuel costs were significant for gas and coal. Capital costs and capital recovery charge was most significant with coal and gasification technology. Without capital recovery, cash costs favour the use of bitumen and coke. Gasification would need lower capital and lower capital recovery to compete with direct burning. It was concluded that direct burning of bitumen can compete with natural gas. With price volatility anticipated, dual fuel capability for bitumen and gas has merit. Petroleum coke can be produced or retrieved from stockpiles. Utility supply costs of direct burning of coke is

  3. Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Haider Abbas Khwaja

    2015-08-01

    Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

  4. Understanding Colombian Amazonian white sand forests

    NARCIS (Netherlands)

    Peñuela-Mora, M.C.

    2014-01-01

    Although progress has been made in studies on white sand forests in the Amazon, there is still a considerable gap in our knowledge of the unique species composition of white sand forests and their structure and dynamics, especially in Western Amazon. This thesis aims to fill this gap by addressing

  5. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

    2012-01-01

    Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...

  6. Japan's involvement in oil sands development

    International Nuclear Information System (INIS)

    Sugiura, T.

    1994-01-01

    According to Japanese national policy, exploration and development by Japanese companies in overseas countries are promoted in order to ensure stable oil supplies. Japan Canada Oil Sands Limited (JACOS), part of the JAPEX group, was established during the 1978 world oil crisis to explore and develop Canadian oil sand resources in accordance with Japan's national policy. The JAPEX group, including JACOS, has invested $123 million in oil sands projects in Alberta. JAPEX's first involvement in oil sands was in the Primrose Project operated by Norcen in the Cold Lake area. Five years of cyclic steam stimulation pilot tests did not produce sufficiently good results to justify further operation. The second involvement was the PCEJ Project, a joint effort by four companies that are participating in a bitumen recovery test project in the Athabasca Deposit. JACOS holds 2,452 km 2 of oil sands leases in Alberta. Tests conducted since 1978 in the PCEJ Project include multiwell steam injection pilot tests, some of which showed promise. JACOS is also participating in steam assisted gravity drainage projects and in federal/provincial research programs. Obstacles identified in developing Alberta oil sands are the lack of a bitumen pipeline to Edmonton and the insufficient length of oil sands leases (currently 10 years), given the difficulties of oil sand development. 10 figs

  7. Seasonal fluctuations of phlebotomines sand fly populations ...

    African Journals Online (AJOL)

    An entomological survey of phlebotomine sand flies was conducted in the Moulay Yacoub province, central Morocco. An anthropic niche (Ouled Aid) and a wild niche (Zliligh) were selected. Sand flies were collected twice a month between April 2011 and March 2012, using sticky traps and CDC light traps. 3675 specimens ...

  8. On shelterbelt design for combating sand invasion.

    NARCIS (Netherlands)

    Mohammed, A.E.; Stigter, C.J.; Adam, H.S.

    1996-01-01

    After a review of the scarce literature on using trees against sand encroachment, a quantitative experiment with a wide shelterbelt to combat sand invasion is reported on. Experimental work was carried out at the northwestern border of the Gezira Scheme (Sudan), an area of severe land degradation

  9. Design of dry sand soil stratified sampler

    Science.gov (United States)

    Li, Erkang; Chen, Wei; Feng, Xiao; Liao, Hongbo; Liang, Xiaodong

    2018-04-01

    This paper presents a design of a stratified sampler for dry sand soil, which can be used for stratified sampling of loose sand under certain conditions. Our group designed the mechanical structure of a portable, single - person, dry sandy soil stratified sampler. We have set up a mathematical model for the sampler. It lays the foundation for further development of design research.

  10. Pattern formation - Instabilities in sand ripples

    DEFF Research Database (Denmark)

    Hansen, J. L.; v. Hecke, M.; Haaning, A.

    2001-01-01

    Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...

  11. Flowability in crushed sand mortar

    Directory of Open Access Journals (Sweden)

    Cabrera, O. A.

    2010-12-01

    Full Text Available The present experimental study explored the relationship between mortar flowability and the voids content in crushed sand to determine the effect of grain shape and surface texture as well as dust content on the behaviour of fresh mortar. The findings revealed a close correlation between voids content and the volume of paste needed for mortar to begin to flow as a continuous material, mortar flowability and the water content needed to attain a given flowability. The comparison of the empirical findings to the results obtained with the Larrard (1, 2 model provided further information on the effect of sand grain morphology on fresh mortars.

    En el presente trabajo se plantea un estudio experimental de la fluidez de morteros basado en el contenido de vacíos de arenas machacadas, para comprender la influencia de la forma y textura superficial de los granos de arena y del contenido de polvo de las mismas sobre el estado fresco de morteros. Los resultados muestran la estrecha relación entre el contenido de vacíos entre granos y los volúmenes de pasta necesarios para iniciar el escurrimiento como un material continuo, la fluidez de los morteros, el contenido de agua para alcanzar una determinada fluidez, etc. El comportamiento evaluado se compara con resultados obtenidos aplicando el modelo de F. de Larrard (1, 2, permitiendo de este modo obtener mayor información de la influencia de la morfología de los granos de la arena sobre el estado fresco de los morteros.

  12. Sand transportation and reverse patterns over leeward face of sand dune

    Science.gov (United States)

    Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

    2017-04-01

    Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux

  13. An Intervention Based on Video Feedback and Questioning to Improve Tactical Knowledge in Expert Female Volleyball Players.

    Science.gov (United States)

    Moreno, M Perla; Moreno, Alberto; García-González, Luis; Ureña, Aurelio; Hernández, César; Del Villar, Fernando

    2016-06-01

    This study applied an intervention program, based on video feedback and questioning, to expert female volleyball players to improve their tactical knowledge. The sample consisted of eight female attackers (26 ± 2.6 years old) from the Spanish National Volleyball Team, who were divided into an experimental group (n = 4) and a control group (n = 4). The video feedback and questioning program applied in the study was developed over eight reflective sessions and consisted of three phases: viewing of the selected actions, self-analysis and reflection by the attacker, and joint player-coach analysis. The attackers were videotaped in an actual game and four clips (situations) of each of the attackers were chosen for each reflective session. Two of the clips showed a correct action by the attacker, and two showed an incorrect decision. Tactical knowledge was measured by problem representation with a verbal protocol. The members of the experimental group showed adaptations in long-term memory, significantly improving their tactical knowledge. With respect to conceptual content, there was an increase in the total number of conditions verbalized by the players; with respect to conceptual sophistication, there was an increase in the indication of appropriate conditions with two or more details; and finally, with respect to conceptual structure, there was an increase in the use of double or triple conceptual structures. The intervention program, based on video feedback and questioning, in addition to on-court training sessions of expert volleyball players, appears to improve the athletes' tactical knowledge. © The Author(s) 2016.

  14. Injury risk is low among world-class volleyball players: 4-year data from the FIVB Injury Surveillance System.

    Science.gov (United States)

    Bere, Tone; Kruczynski, Jacek; Veintimilla, Nadège; Hamu, Yuichiro; Bahr, Roald

    2015-09-01

    Little is known about the rate and pattern of injuries in international volleyball competition. To describe the risk and pattern of injuries among world-class players based on data from the The International Volleyball Federation (FIVB) Injury Surveillance System (ISS) (junior and senior, male and female). The FIVB ISS is based on prospective registration of injuries by team medical staff during all major FIVB tournaments (World Championships, World Cup, World Grand Prix, World League, Olympic Games). This paper is based on 4-year data (September 2010 to November 2014) obtained through the FIVB ISS during 32 major FIVB events (23 senior and 9 junior). The incidence of time-loss injuries during match play was 3.8/1000 player hours (95% CI 3.0 to 4.5); this was greater for senior players than for junior players (relative risk: 2.04, 1.29 to 3.21), while there was no difference between males and females (1.04, 0.70 to 1.55). Across all age and sex groups, the ankle was the most commonly injured body part (25.9%), followed by the knee (15.2%), fingers/thumb (10.7%) and lower back (8.9%). Injury incidence was greater for centre players and lower for liberos than for other player functions; injury patterns also differed between player functions. Volleyball is a very safe sport, even at the highest levels of play. Preventive measures should focus on acute ankle and finger sprains, and overuse injuries in the knee, lower back and shoulder. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. A soft patellar tendon on ultrasound elastography is associated with pain and functional deficit in volleyball players.

    Science.gov (United States)

    Ooi, Chin Chin; Richards, Paula J; Maffulli, Nicola; Ede, David; Schneider, Michal E; Connell, David; Morrissey, Dylan; Malliaras, Peter

    2016-05-01

    To investigate the diagnostic performance of grey scale Ultrasound (US), power Doppler (PD) and US elastography for diagnosing painful patellar tendinopathy, and to establish their relationship with Victorian Institute of Sport Assessment-Patella (VISA-P) scores in a group of volleyball players with and without symptoms of patellar tendinopathy. Cross-sectional study. Thirty-five volleyball players (70 patellar tendons) were recruited during a national university volleyball competition. Players were imaged with conventional US followed by elastography. The clinical findings of painful patellar tendons were used as the reference standard for diagnosing patellar tendinopathy. In addition, all participants completed the VISA-P questionnaires. Of the 70 patellar tendons, 40 (57.1%) were clinically painful. The diagnostic accuracy of grey scale US, PD and elastography were 60%, 50%, 62.9%, respectively, with sensitivity/specificity of 72.5%/43.3%, 12.5%/100%, and 70%/53.3%, respectively. Combined US elastography and grey scale imaging achieved 82.5% sensitivity, 33.3% specificity and 61.4% accuracy while routine combination technique of PD and grey scale imaging revealed 72.5% sensitivity, 43.3% specificity and 60.0% accuracy. Tendons in players categorized as soft on elastography had statistically significantly greater AP thickness (p<0.001) and lower VISA-P scores (p=0.004) than those categorized as hard. There was no significant association between grey scale US abnormalities (hypoechogenicities and/or fusiform swelling) and VISA-P scores (p=0.098). Soft tendon properties depicted by US elastography may be more related to patellar tendon symptoms compared to grey scale US abnormalities. The supplementation of US elastography to conventional US may enhance the sensitivity for diagnosing patellar tendinopathy in routine clinical practice. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Ultrasound assessment of the posterior circumflex humeral artery in elite volleyball players: Aneurysm prevalence, anatomy, branching pattern and vessel characteristics.

    Science.gov (United States)

    van de Pol, Daan; Maas, Mario; Terpstra, Aart; Pannekoek-Hekman, Marja; Alaeikhanehshir, Sena; Kuijer, P Paul F M; Planken, R Nils

    2017-03-01

    To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players. Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ≥150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter. The PCHA and DBA were identified in 100 % and 93 % (260/280) of cases, respectively. The prevalence of PCHA aneurysms was 4.6 % (13/280). All aneurysms were detected in proximal PCHA originating from the axillary artery (AA). The PCHA originated from the AA in 81 % of cases (228/280), and showed a curved course dorsally towards the humeral head in 93 % (211/228). The DBA originated from the AA in 73 % of cases (190/260), and showed a straight course parallel to the AA in 93 % (177/190). PCHA aneurysm prevalence in elite volleyball players is high and associated with a specific branching type: a PCHA that originates from the axillary artery. Radiologists should have a high index of suspicion for this vascular overuse injury. For the first time vessel characteristics and reference values are described to facilitate ultrasound assessment. • Prevalence of PCHA aneurysms is 4.6 % among elite volleyball players. • All aneurysms are in proximal PCHA that originates directly from AA. • Vessel characteristics and reference values are described to facilitate US assessment. • Mean PCHA and DBA diameters can be used as reference values. • Radiologists need a high index of suspicion for this vascular overuse injury.

  17. Focal vibration of quadriceps muscle enhances leg power and decreases knee joint laxity in female volleyball players.

    Science.gov (United States)

    Brunetti, O; Botti, F M; Roscini, M; Brunetti, A; Panichi, R; Filippi, G M; Biscarini, A; Pettorossi, V E

    2012-12-01

    This double-blind randomized controlled study aims at determining the effect of repeated muscle vibration (rMV) on explosive and reactive leg power and on knee laxity of female volleyball players. Eighteen voluntary volleyball athletes, belonging to the same senior regional level team (age=22.7 ± 3 years, height=180.3 ± 5 cm, mass= 64 ± 4 kg) were assigned to three groups (N.=6) for vibration on contracted quadriceps (VC), vibration on relaxed muscle (VR), and sham vibration (NV), respectively. Intervention consisted in 3 rMV sessions performed in 3 consecutive days. In each session, 100 Hz, 300-500 μm amplitude vibratory stimuli were bilaterally delivered to the quadriceps in three consecutive 10-minutes applications. Explosive and reactive leg power and knee joint laxity were evaluated 1 day before, and 1, 30, and 240 days after intervention. In VC group, explosive and reactive leg power increased respectively by ~16% and ~9% at 1 day, by ~19% and ~11% at 30 days and by ~26% and ~13% at 240 days, concomitantly knee laxity decreased by ~6%, ~15% and ~18% at the same times. These changes were significantly larger than in the other groups, in which leg power increment and knee joint laxity reduction remained close to ~3%, ~5% and ~10% at 1, 30 and 240 days, respectively. Combined bilateral voluntary contraction and rMV of the quadriceps muscles is a short-lasting, non-invasive technique that can significantly and persistently improve muscle performance and knee laxity in volleyball women players.

  18. Developing new markets for oil sands products

    International Nuclear Information System (INIS)

    Crandall, G.

    2004-01-01

    This paper presents a review by Purvin and Gertz of western Canadian crude oil supply. This energy consulting firm provides advise to the energy sector. It suggests that oil sands production will surpass declining conventional production. Oil sands supply includes bitumen, synthetic crude oil (SCO), and diluent. It is forecasted that oil sands will increase from 42 per cent of western supply in 2002 to 78 per cent in 2015. The potential of Alberta's oil sands was discussed along with a recent study of refined products and petrochemicals from bitumen. Upgrading, refining and petrochemical case studies were presented. The author examined if a Canadian oil sands upgrading project with high capital costs can be competitive with competing projects in the United States and internationally. In addition to supply and demand issues, the presentation examined infrastructure capability and market potential in the United States. The economic potential and risks of preferred business cases compared to upgrading to SCO were also evaluated. 15 figs

  19. Numerical simulation of aeolian sand ripples

    International Nuclear Information System (INIS)

    Kang Liqiang; Guo Liejin

    2004-01-01

    With a new horizontal saltation displacement vector, a model is implemented to simulate the initiation and evolution of aeolian sand ripples. In the model, saltation distance considers the effects of surface height and slope. A linear stability analysis is also carried out for formation of sand ripples. The results show that, the model can be able to successfully reproduce sand ripples which can increase in scale by merging of small ripples. The linear stability analysis indicates that sand ripples appear when the relaxation rate parameter is below a threshold value and wind strength parameter is larger than a critical value. The results also verified that the formation of sand ripples is a self-organization process

  20. Nutrition Education by a Registered Dietitian Improves Dietary Intake and Nutrition Knowledge of a NCAA Female Volleyball Team

    Science.gov (United States)

    Valliant, Melinda W.; Pittman Emplaincourt, Heather; Wenzel, Rachel Kieckhaefer; Garner, Bethany Hilson

    2012-01-01

    Eleven female participants from a NCAA Division I volleyball team were evaluated for adequate energy and macronutrient intake during two off-seasons. Total energy and macronutrient intake were assessed by food records and results were compared against estimated needs using the Nelson equation. Dietary intervention was employed regarding the individual dietary needs of each athlete as well as a pre- and post-sports nutrition knowledge survey. Post dietary intervention, total energy, and macronutrient intake improved, as well as a significant improvement in sports nutrition knowledge (p < 0.001). Nutrition education is useful in improving dietary intake and nutrition knowledge of female athletes. PMID:22822449

  1. FeynRules - Feynman rules made easy

    OpenAIRE

    Christensen, Neil D.; Duhr, Claude

    2008-01-01

    In this paper we present FeynRules, a new Mathematica package that facilitates the implementation of new particle physics models. After the user implements the basic model information (e.g. particle content, parameters and Lagrangian), FeynRules derives the Feynman rules and stores them in a generic form suitable for translation to any Feynman diagram calculation program. The model can then be translated to the format specific to a particular Feynman diagram calculator via F...

  2. Delayed rule following

    OpenAIRE

    Schmitt, David R.

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [SD], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the SD. The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative even...

  3. Physical and Temporal Characteristics of Under 19, Under 21 and Senior Male Beach Volleyball Players

    Directory of Open Access Journals (Sweden)

    Alexandre Medeiros, Rui Marcelino, Isabel Mesquita, José Manuel Palao

    2014-09-01

    Full Text Available This study aimed to assess the effects of age groups and players’ role (blocker vs. defender specialist in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19, 933 rallies from Under 21 (U21, and 1480 rallies from senior (senior (Men’s Swatch World Championships, 2010-2011 were observed using video match analysis. Cluster analysis was used to set teams’ competitive levels and establish quality of opposition as “balanced”, “moderate balanced” and “unbalanced” games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies and physical (number of jumps and number of hits done by defenders and blockers characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player’s role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19 and U21; b moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c unbalanced games, no significant findings were shown. This study suggests differences in players’ performances according to age group and players’ role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics.

  4. Tactic determinants of game practiced by middle attacker in men’s volleyball

    Directory of Open Access Journals (Sweden)

    Gustavo De Conti Teixeira Costa

    2016-07-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n3p371   Among volleyball skills, spike is responsible for the highest number of scores, and the first tempo of attack is related to the higher incidence of score a point, by hindering the defensive opponent’s action. However, most of the studies show general results and do not specify the conditions and constraints of each attack zone. Thus, the aim of this study was analyzing the offensive game (complex I performed by the middle attacker at the 2014/2015 National men’s Brazilian Championship (Superliga. The sample wascomposed by 142 games of 12 teams, totaling 5350 receptions, setting and spikes actions. The results showed that the middle spikes occurred mostly after receptions A and B, being the most frequent attack scoring point as well as the most powerful one. Moreover, the relationship between the reception effect and setting effect was observed, showing that the best receptions influenced the setting type and the attack effect. Therefore, the middle attack had effective effect in the winning score, since it decreased the chances of opponent’s defense, due to the reduced time to defensive organization. Finally, the situational constraints delimited the middle attacker actions. Based on the above, we suggest that future studies should restrict the analysis conditions and situational constraints of each specific game situation.

  5. Heart rate during basketball game play and volleyball drills accurately predicts oxygen uptake and energy expenditure.

    Science.gov (United States)

    Scribbans, T D; Berg, K; Narazaki, K; Janssen, I; Gurd, B J

    2015-09-01

    There is currently little information regarding the ability of metabolic prediction equations to accurately predict oxygen uptake and exercise intensity from heart rate (HR) during intermittent sport. The purpose of the present study was to develop and, cross-validate equations appropriate for accurately predicting oxygen cost (VO2) and energy expenditure from HR during intermittent sport participation. Eleven healthy adult males (19.9±1.1yrs) were recruited to establish the relationship between %VO2peak and %HRmax during low-intensity steady state endurance (END), moderate-intensity interval (MOD) and high intensity-interval exercise (HI), as performed on a cycle ergometer. Three equations (END, MOD, and HI) for predicting %VO2peak based on %HRmax were developed. HR and VO2 were directly measured during basketball games (6 male, 20.8±1.0 yrs; 6 female, 20.0±1.3yrs) and volleyball drills (12 female; 20.8±1.0yrs). Comparisons were made between measured and predicted VO2 and energy expenditure using the 3 equations developed and 2 previously published equations. The END and MOD equations accurately predicted VO2 and energy expenditure, while the HI equation underestimated, and the previously published equations systematically overestimated VO2 and energy expenditure. Intermittent sport VO2 and energy expenditure can be accurately predicted from heart rate data using either the END (%VO2peak=%HRmax x 1.008-17.17) or MOD (%VO2peak=%HRmax x 1.2-32) equations. These 2 simple equations provide an accessible and cost-effective method for accurate estimation of exercise intensity and energy expenditure during intermittent sport.

  6. Critical State of Sand Matrix Soils

    Science.gov (United States)

    Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

    2014-01-01

    The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

  7. Invasive plants on disturbed Korean sand dunes

    Science.gov (United States)

    Kim, Kee Dae

    2005-01-01

    The sand dunes in coastal regions of South Korea are important ecosystems because of their small size, the rare species found in this habitat, and the beautiful landscapes they create. This study investigated the current vegetative status of sand dunes on three representative coasts of the Korean peninsula, and on the coasts of Cheju Island, and assessed the conditions caused by invasive plants. The relationships between the degree of invasion and 14 environmental variables were studied. Plots of sand dunes along line transects perpendicular to the coastal lines were established to estimate vegetative species coverage. TWINSPAN (Two-Way Indicator Species Analysis), CCA (Canonical Correspondence Analysis), and DCCA (Detrended Canonical Correspondence Analysis) were performed to classify communities on sand dunes and assess species composition variation. Carex kobomugi, Elymus mollis, and Vitex rotundifolia were found to be the dominant species plotted on the east, the west, and the peripheral coasts of Cheju Island, respectively. Vegetation on the south coast was totally extinct. The 19 communities, including representative C. kobomugi, C. kobomugi- Ixeris repens, C. kobomugi- Oenothera biennis, E. mollis, Lolium multiflorum- Calystegia soldanella, and V. rotundifolia- C. kobomugi, were all classified according to TWINSPAN. Oenothera biennis and L. multiflorum were exotics observed within these native communities. CCA showed that invasive native and exotic species distribution was segregated significantly, according to disturbance level, exotic species number, gravel, sand and silt contents, as well as vegetation size. It further revealed that human disturbance can strongly favor the settlement of invasive and exotic species. Restoration options to reduce exotic plants in the South Korean sand dune areas were found to be the introduction of native plant species from one sand dune into other sand dune areas, prohibition of building and the introduction of exotic

  8. Effects of Student Skill Level on Knowledge, Decision Making, Skill Execution and Game Performance in a Mini-Volleyball Sport Education Season

    Science.gov (United States)

    Mahedero, Pilar; Calderón, Antonio; Arias-Estero, José Luis; Hastie, Peter A.; Guarino, Anthony J.

    2015-01-01

    The purpose of the paper was to examine the effects of student skill level on knowledge, decision making, skill execution and game performance in a mini-volleyball Sport Education season. Forty-eight secondary school students from two classes participated in a 12 lesson season. Knowledge, decision-making and skill execution (components of game…

  9. Evaluating the Relation between Dominant and Non-Dominant Hand Perimeters and Handgrip Strength of Basketball, Volleyball, Badminton and Handball Athletes

    Science.gov (United States)

    Kaplan, Defne Öcal

    2016-01-01

    In this study, it's aimed to evaluate the relation between dominant and non-dominant hand perimeters and handgrip strength of basketball, volleyball, badminton and handball athletes. Totally 101 active athletes (49 females, 52 male), of the average age in female 20±1.42 years, in male 21±1.99 years, joined to this study. Height, body weight, BMI…

  10. Impact d'un module de formation à l'arbitrage sur l'implicaiton des bénévoles dans le volley-ball

    OpenAIRE

    Van Hoye, Martin; Roulin, Céline; Cloes, Marc

    2014-01-01

    En raison du manque de bénévoles dans les clubs de volley-ball, les clubs doivent trouver des solutions. Dans cette étude, nous avons proposé un module de formation à l'arbitrage afin d'impliquer des parents, des amis et des joueurs d'autres équipes dans la gestion de matches.

  11. Anthropometric, morphological and somatotype characteristics of athletes of the Brazilian Men’s volleyball team: an 11-year descriptive study

    Directory of Open Access Journals (Sweden)

    Edio Luiz Petroski

    2013-03-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2013v15n2p184 This study analyzed the anthropometric and morphological characteristics of the adult male players in the Brazilian volleyball team for 11 years. The sample comprised 92 athletes selected for the national team from 1995 to 2005. Anthropometric measures were collected and body composition and somatotype components were estimated. Oneway ANOVA and the Bonferroni test were used for descriptive statistical analysis, and the level of significance was set at p<0.05. Along the 11 years, there was a significant increase in the flexed arm perimeter, humerus diameter and lean mass. Skinfold thickness and percent body fat tended to decrease. Height increased and was greater than 1.97 m. The somatotype of the volleyball players in the Brazilian team changed along the years. Ectomorphic and mesomorphic somatotypes were the most frequent. In 11 years, the athletes selected for the Brazilian team had an increase in body mass and a decrease in skinfold thickness and percent body fat. The most frequent anthropometric classifications were mesomorph-ectomorph for five years, followed by mesomorphic-ectomorph for three years, which suggests that greater height and low body fat were taken into consideration when selecting athletes for the national team

  12. Analysis of the Response Speed of Musculature of the Knee in Professional Male and Female Volleyball Players

    Science.gov (United States)

    Rodríguez-Ruiz, D.; Diez-Vega, I.; Rodríguez-Matoso, D.; Fernandez-del-Valle, M.; Sagastume, R.; Molina, J. J.

    2014-01-01

    The aim of this study was to evaluate the normalized response speed (Vrn) of the knee musculature (flexor and extensor) in high competitive level volleyball players using tensiomyography (TMG) and to analyze the muscular response of the vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), and biceps femoris (BF) in accordance with the specific position they play in their teams. One hundred and sixty-six players (83 women and 83 men) were evaluated. They belonged to eight teams in the Spanish women's superleague and eight in the Spanish men's superleague. The use of Vrn allows avoiding possible sample imbalances due to anatomical and functional differences and demands. We found differences between Vrn in each of the muscles responsible for extension (VM, RF, and VL) and flexion (BF) regardless of the sex. Normalized response speed differences seem to be larger in setters, liberos and outside players compared to middle blockers and larger in males when compared to females. These results of Vrn might respond to the differences in the physical and technical demands of each specific position, showing an improved balance response of the knee extensor and flexor musculature in male professional volleyball players. PMID:25003109

  13. Dominant vs. non-dominant shoulder morphology in volleyball players and associations with shoulder pain and spike speed.

    Science.gov (United States)

    Challoumas, Dimitrios; Artemiou, Andreas; Dimitrakakis, Georgios

    2017-01-01

    The aims of our study were to compare the dominant (DOM) and non-dominant (NDOM) shoulders of high-level volleyball athletes and identify possible associations of shoulder adaptations with spike speed (SS) and shoulder pathology. A total of 22 male volleyball players from two teams participating in the first division of the Cypriot championship underwent clinical shoulder tests and simple measurements around their shoulder girdle joints bilaterally. SS was measured with the use of a sports speed radar. Compared with the NDOM side, the DOM scapula was more lateralised, the DOM dorsal capsule demonstrated greater laxity, the DOM dorsal muscles stretching ability was compromised, and the DOM pectoralis muscle was more lengthened. Players with present or past DOM shoulder pain demonstrated greater laxity in their DOM dorsal capsule, tightening of their DOM inferior capsule, and lower SS compared with those without shoulder pain. Dorsal capsule measurements bilaterally were significant predictors of SS. None of the shoulder measurements was associated with team roles or infraspinatus atrophy, while scapular lateralisation was more pronounced with increasing years of experience, and scapular antetilting was greater with increasing age. Adaptations of the DOM shoulder may be linked to pathology and performance. We describe simple shoulder measurements that may have the potential to predict chronic shoulder injury and become part of injury prevention programmes. Detailed biomechanical and large prospective studies are warranted to assess the validity of our findings and reach more definitive conclusions.

  14. Analysis of the Response Speed of Musculature of the Knee in Professional Male and Female Volleyball Players

    Directory of Open Access Journals (Sweden)

    D. Rodríguez-Ruiz

    2014-01-01

    Full Text Available The aim of this study was to evaluate the normalized response speed (Vrn of the knee musculature (flexor and extensor in high competitive level volleyball players using tensiomyography (TMG and to analyze the muscular response of the vastus medialis (VM, rectus femoris (RF, vastus lateralis (VL, and biceps femoris (BF in accordance with the specific position they play in their teams. One hundred and sixty-six players (83 women and 83 men were evaluated. They belonged to eight teams in the Spanish women’s superleague and eight in the Spanish men’s superleague. The use of Vrn allows avoiding possible sample imbalances due to anatomical and functional differences and demands. We found differences between Vrn in each of the muscles responsible for extension (VM, RF, and VL and flexion (BF regardless of the sex. Normalized response speed differences seem to be larger in setters, liberos and outside players compared to middle blockers and larger in males when compared to females. These results of Vrn might respond to the differences in the physical and technical demands of each specific position, showing an improved balance response of the knee extensor and flexor musculature in male professional volleyball players.

  15. Disordered eating behaviors in young volleyball players: can be the coach’s leadership style an intervenient factor?

    Directory of Open Access Journals (Sweden)

    Leonardo de Sousa Fortes

    2017-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n1p84   The aim of this study was to analyze the influence of coach’s leadership style on eating disorders (ED in female volleyball athletes. This is a prospective study with 73 participants of sub-17 state of Pernambuco Championship. The Eating Attitudes Test was applied to evaluate ED. The perception of the coach’s leadership style was evaluated with Leader Sport Scale subscales. Triceps and subscapular skinfolds were measured to estimate body fat percentage. The findings showed no influence of “Training-Instruction” on ED (F(3, 70=45.02; R²=0.12; p=0.34. The “Social Support” subscale showed statically significant influence on ED (F(4, 69=59.77; R²=-0.16; p=0.02. However, the results indicated no statically significant relationship of “Reforce” subscale with ED (F(5, 68=52.40; R²=0.13; p=0.17. The “Democratic” subscale so showed no influence on ED F(6, 67=49.08; R²=0.10; p=0.21. Finally, the “Autocratic” subscale showed influence on ED (F(7, 66=67.23; R²=0.18; p=0.01. We concluded that the coach’s leadership style (social support and autocratic influenced the adoption of DEB in young female volleyball athletes.

  16. The effect of aquatic plyometric training with and without resistance on selected physical fitness variables among volleyball players

    Directory of Open Access Journals (Sweden)

    K. KAMALAKKANNAN

    2011-06-01

    Full Text Available The purpose of this study is to analyze the effect of aquatic plyometric training with and without the use ofweights on selected physical fitness variables among volleyball players. To achieve the purpose of these study 36physically active undergraduate volleyball players between 18 and 20 years of age volunteered as participants.The participants were randomly categorized into three groups of 12 each: a control group (CG, an aquaticPlyometric training with weight group (APTWG, and an aquatic Plyometric training without weight group(APTWOG. The subjects of the control group were not exposed to any training. Both experimental groupsunderwent their respective experimental treatment for 12 weeks, 3 days per week and a single session on eachday. Speed, endurance, and explosive power were measured as the dependent variables for this study. 36 days ofexperimental treatment was conducted for all the groups and pre and post data was collected. The collected datawere analyzed using an analysis of covariance (ANCOVA and followed by a Scheffé’s post hoc test. The resultsrevealed significant differences between groups on all the selected dependent variables. This study demonstratedthat aquatic plyometric training can be one effective means for improving speed, endurance, and explosivepower in volley ball players

  17. Watching Faults Grow in Sand

    Science.gov (United States)

    Cooke, M. L.

    2015-12-01

    Accretionary sandbox experiments provide a rich environment for investigating the processes of fault development. These experiments engage students because 1) they enable direct observation of fault growth, which is impossible in the crust (type 1 physical model), 2) they are not only representational but can also be manipulated (type 2 physical model), 3) they can be used to test hypotheses (type 3 physical model) and 4) they resemble experiments performed by structural geology researchers around the world. The structural geology courses at UMass Amherst utilize a series of accretionary sandboxes experiments where students first watch a video of an experiment and then perform a group experiment. The experiments motivate discussions of what conditions they would change and what outcomes they would expect from these changes; hypothesis development. These discussions inevitably lead to calculations of the scaling relationships between model and crustal fault growth and provide insight into the crustal processes represented within the dry sand. Sketching of the experiments has been shown to be a very effective assessment method as the students reveal which features they are analyzing. Another approach used at UMass is to set up a forensic experiment. The experiment is set up with spatially varying basal friction before the meeting and students must figure out what the basal conditions are through the experiment. This experiment leads to discussions of equilibrium and force balance within the accretionary wedge. Displacement fields can be captured throughout the experiment using inexpensive digital image correlation techniques to foster quantitative analysis of the experiments.

  18. Sudan challenges the sand dragon.

    Science.gov (United States)

    Tinker, J

    1978-01-01

    Formerly productive areas have become wasteland as the desert advances in the Sudan. To understand how desertification is undermining the very survival of the Sahel, one ecosystem is reviewed in detail here: the gum arabic zone of Kordofan. After cotton, gum arabic is Sudan's largest export, worth from $14-26 million in recent years. In this zone the ecologically balanced cycle of gum gardens, fire, grain crops, and fallow is now breaking down; the 1968-1973 drought having in many areas delivered the final blow. Because of a growing population, the cultivation period is extended, and the soil becomes impoverished. Overgrazing in the fallow period, and the lopping of gum trees for firewood is producing a low return on the gum trees. Without this gum to harvest for cash, farmers must repeatedly replant their subsistence crops until the land becomes useless sand. The Sudanese have recognized the problem earlier than most, and a number of imaginative and practicable pilot projects are already in use: 1) waterpoint management; 2) construction of firebreaks; 3) land threatened by shifting dunes has been enclosed by stockproof fence and afforested with local trees; and 4) shelter belts have been planted around town perimeters where old gum tree stumps have started to sprout and the grass is reseeding itself. Out of these pilot projects, and with the advice of the U.N. Environment Program, the U.N. Development Program, and FAO, the Sudanese have developed a modest $26 million desert encroachment control and rehabilitation program (DECARP).

  19. Sand to Root Transfer of PAHs and PCBs by Carrots Grown on Sand with Pure Substances and Biosolids Amended Sand

    OpenAIRE

    Sablayrolles, Caroline; Montréjaud-Vignoles, Mireille; Silvestre, Jérôme; Patria, Lucie

    2006-01-01

    A study on behaviour of trace organic compounds (Polycyclic Aromatic Hydrocarbons, PAH, and Polychlorinated Biphenyls, PCB) in a sand-plant system has been carried out, with the reclamation of wastewater treatment plant biosolids for agriculture in mind. Carrot plants (Daucus carota) were grown on soilless culture (sand), to provide optimal transfer conditions, in plant containers inside a temperature regulated greenhouse. There were two types of experiment. The trace organic compounds have i...

  20. A long-term cohort study of the muscle apparatus of female volleyball players after the application of a compensatory programme

    Directory of Open Access Journals (Sweden)

    Tamara Čučková

    2017-11-01

    Full Text Available Volleyball is a sport with great unilateral load that can have a negative impact on a postural system. The aim of the study was to perform a detailed examination of posture and muscle imbalance in elite female volleyball athletes and, according to the results of the examination, to put together compensatory exercises and to assess their effect. A group of elite junior female volleyball players (n = 12 was examined by an experienced physiotherapist using a complex kinesiological analysis especially focused on body posture (from frontal, sagittal and dorsal plane, shortened muscles and performance of basic movement patterns (hip extension, hip abduction, sit-up, cervical flexion, shoulder abduction, push-up. The preliminary examination showed that every tested player had some kind of posture deficiency. The compensatory programme, consisting of breathing techniques, stretching exercises, strengthening exercises with an elastic band, and balance exercises with a Bosu balance trainer, was applied at the end of every training session over the competitive parts of two volleyball seasons. Before the application of the exercise programme we found flat back in 92% subjects, whereas 33% of subjects exhibited it after compensation. Improvement was noted in the intensified lumbar lordosis (from 50% subjects to 42%, and scoliotic body posture (from 50% to 17%. The biggest improvement in shortened muscles in the upper body was observed on the m. levator scapulae (from 83% subjects to 8% and the m. trapezius (from 42% subjects to 8%; and in the lower body m. triceps surae (from 75% subjects to 33% and hip abductors (from 83% subjects to 25%. The study suggests that balance exercises with a Bosu balance trainer and exercises with an exercise elastic band seem to be useful for volleyball since we noted improvement in body posture, movement patterns and muscle shortness. We therefore highly recommend this compensatory programme.

  1. experimental studies of sand production from unconsolidated

    African Journals Online (AJOL)

    ES Obe

    aDepartment of Chemical Engineering, University of Lagos, Lagos, Nigeria. bDepartment of Petroleum ... as risk of well failure, erosion of pipelines and surface facilities, sand separa- ... ment, theoretical and numerical analysis have lead to the ...

  2. A study of global sand seas

    Science.gov (United States)

    McKee, Edwin D.

    1979-01-01

    The birth of the idea that led to this publication on "Global Sand Seas" dates back to the late 1920's. At that time I was engaged in a study of the Coconino Sandstone of Arizona's Grand Canyon. Considerable controversy existed then as to whether this sandstone was a subaqueous deposit or was composed of wind-formed dunes. It became apparent that definitive literature was sparse or lacking on types of dunes, global distribution of these types, the mechanics of their development, the precise nature of their internal structure of cross-stratificiation, and the relation of wind systems to these sand forms. Especially lacking were data on criteria that could confidently be used in the recognition of ancient dunes. The common denominator in this publication is eolian sand bodies. Although the book is concerned primarily with desert sand seas, the subject matter is not restricted to deserts; it includes many references to deposits of coastal sand and to sand bodies in humid climates. Nor does the book deal exclusively with dunes, which, according to most definitions, involve mounds or hills. Many references are made to sand sheets, sand stringers, and other types of sand deposits that have no prominent topographic expression. All sand bodies accumulated by the action of wind are discussed. Chapters A-J of this publication are primarily topical. Chapters cover the grain texture, the color, and the structure of modern dunes and other eolian sands. Special treatment is given to the relation of wind data to dune interpretation, the evolution of form in current-deposited sand bodies as determined from experimental studies, and the discriminant analysis technique for differentiating between coastal and inland desert sands. This topical part of the publication also includes an analysis of criteria used in ancient deposits to interpret their eolian genesis and a consideration of economic application of the principles described, including a discussion of potentials and problems

  3. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...... MCPA degradation for prolonged periods in flow-through sand columns. In an expression study of catabolic genes with putative roles in phenoxy acid degradation, we observed a marked upregulation of catabolic genes cadA and tfdC upon exposure to MCPA, 2,4-D, dichlorprop and mecoprop in strain PM2, which...

  4. Geotechnical properties of crude oil contaminated sand

    International Nuclear Information System (INIS)

    Puri, V.K.; Das, B.M.; Cook, E.E.; Shin, E.C.

    1994-01-01

    Contamination of soil due to an oil spill influences its subsequent engineering behavior. An investigation was conducted to study the effect of crude oil contamination on compaction characteristics, shear strength, one-dimensional compression, and coefficient of permeability. Water permeability was also determined by using commercial grade motor oils as contaminants. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand (based on total stress condition) decreases due to presence of oil within the pore spaces in sand. One dimensional compression characteristics of sand are significantly influenced by oil contamination resulting in a decrease in the value of constrained modulus with increase in the degree of oil contamination compared to the case of dry sand. Water permeability was observed to be a function of the initial viscosity and the degree of saturation due to the contaminating oil

  5. Displacement pile installation effects in sand

    NARCIS (Netherlands)

    Beijer-Lundberg, A.

    2015-01-01

    Installation effects govern the post-installation behaviour of displacement piles in sand. These effects are currently not completely understood. Suitable experimental techniques to model these installation effects include field, laboratory and experimental models. In the current thesis a

  6. Supercritical solvent extraction of oil sand bitumen

    Science.gov (United States)

    Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

    2017-08-01

    The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

  7. Phonological reduplication in sign language: rules rule

    Directory of Open Access Journals (Sweden)

    Iris eBerent

    2014-06-01

    Full Text Available Productivity—the hallmark of linguistic competence—is typically attributed to algebraic rules that support broad generalizations. Past research on spoken language has documented such generalizations in both adults and infants. But whether algebraic rules form part of the linguistic competence of signers remains unknown. To address this question, here we gauge the generalization afforded by American Sign Language (ASL. As a case study, we examine reduplication (X→XX—a rule that, inter alia, generates ASL nouns from verbs. If signers encode this rule, then they should freely extend it to novel syllables, including ones with features that are unattested in ASL. And since reduplicated disyllables are preferred in ASL, such rule should favor novel reduplicated signs. Novel reduplicated signs should thus be preferred to nonreduplicative controls (in rating, and consequently, such stimuli should also be harder to classify as nonsigns (in the lexical decision task. The results of four experiments support this prediction. These findings suggest that the phonological knowledge of signers includes powerful algebraic rules. The convergence between these conclusions and previous evidence for phonological rules in spoken language suggests that the architecture of the phonological mind is partly amodal.

  8. Effect of manufactured sand on the durability characteristics of concrete

    Directory of Open Access Journals (Sweden)

    S. S. SARAVANAN

    2016-12-01

    Full Text Available Concrete is the most sought after material due to increase in construction activities and infrastructural developments. Availability of natural sand is decreasing thereby increase in the cost of construction. In the present work undertaken, an attempt has been made to give an alternative to natural sand. Optimization of replacement of natural sand with manufactured sand in concrete, durability studies such as water absorption, rapid chloride permeability test, sorptivity, acid resistance, alkaline resistance, impact resistance and abrasion resistance of M40 and M50 grades of concrete have been studied with manufactured sand as fine aggregate and compared the results with the conventional sand concrete. The results shows that there is an increase in the durability properties up to 70 % level of replacements of sand with manufactured sand as fine aggregate and for 100 % use of manufactured sand also gives the better durability than the conventional sand concrete.

  9. Studies on various characteristics of concrete structures using crushed sand

    International Nuclear Information System (INIS)

    Mimatsu, Makoto; Sugita, Hideaki; Yonemura, Masataka.

    1985-01-01

    With the recent advances of construction industry, the demands for concrete, hence for aggregate, are rising. The sand as such is in extreme shortage due to the exhaustion of river sand. Under the situation, the recent trends are for the use of crushed sand, i.e. the artificial sand obtained by crushing rocks, which have advantages of stabilized quality and adequate supplies. In building of nuclear power plants requiring large amounts of concrete, the usage of crushed sand is now unavoidable. The following are described : the situation of aggregate in Kyushu. production method of crushed sand and the quality standards, rocks used for crushed stone and sand and the properties, quality survey on crushed sand and the basic tests, characteristic tests of crushed-stone and -sand mixed concrete, the application of crushed sand in structures of the Sendai Nuclear Power Station. (Mori, K.)

  10. A Better Budget Rule

    Science.gov (United States)

    Dothan, Michael; Thompson, Fred

    2009-01-01

    Debt limits, interest coverage ratios, one-off balanced budget requirements, pay-as-you-go rules, and tax and expenditure limits are among the most important fiscal rules for constraining intertemporal transfers. There is considerable evidence that the least costly and most effective of such rules are those that focus directly on the rate of…

  11. Provenance and recycling of Arabian desert sand

    Science.gov (United States)

    Garzanti, Eduardo; Vermeesch, Pieter; Andò, Sergio; Vezzoli, Giovanni; Valagussa, Manuel; Allen, Kate; Kadi, Khalid A.; Al-Juboury, Ali I. A.

    2013-05-01

    This study seeks to determine the ultimate origin of aeolian sand in Arabian deserts by high-resolution petrographic and heavy-mineral techniques combined with zircon U-Pb geochronology. Point-counting is used here as the sole method by which unbiased volume percentages of heavy minerals can be obtained. A comprehensive analysis of river and wadi sands from the Red Sea to the Bitlis-Zagros orogen allowed us to characterize all potential sediment sources, and thus to quantitatively constrain provenance of Arabian dune fields. Two main types of aeolian sand can be distinguished. Quartzose sands with very poor heavy-mineral suites including zircon occupy most of the region comprising the Great Nafud and Rub' al-Khali Sand Seas, and are largely recycled from thick Lower Palaeozoic quartzarenites with very minor first-cycle contributions from Precambrian basement, Mesozoic carbonate rocks, or Neogene basalts. Instead, carbonaticlastic sands with richer lithic and heavy-mineral populations characterize coastal dunes bordering the Arabian Gulf from the Jafurah Sand Sea of Saudi Arabia to the United Arab Emirates. The similarity with detritus carried by the axial Tigris-Euphrates system and by transverse rivers draining carbonate rocks of the Zagros indicates that Arabian coastal dunes largely consist of far-travelled sand, deposited on the exposed floor of the Gulf during Pleistocene lowstands and blown inland by dominant Shamal northerly winds. A dataset of detrital zircon U-Pb ages measured on twelve dune samples and two Lower Palaeozoic sandstones yielded fourteen identical age spectra. The age distributions all show a major Neoproterozoic peak corresponding to the Pan-African magmatic and tectonic events by which the Arabian Shield was assembled, with minor late Palaeoproterozoic and Neoarchean peaks. A similar U-Pb signature characterizes also Jafurah dune sands, suggesting that zircons are dominantly derived from interior Arabia, possibly deflated from the Wadi al

  12. Home advantage in high-level volleyball varies according to set number.

    Science.gov (United States)

    Marcelino, Rui; Mesquita, Isabel; Palao Andrés, José Manuel; Sampaio, Jaime

    2009-01-01

    The aim of the present study was to identify the probability of winning each Volleyball set according to game location (home, away). Archival data was obtained from 275 sets in the 2005 Men's Senior World League and 65,949 actions were analysed. Set result (win, loss), game location (home, away), set number (first, second, third, fourth and fifth) and performance indicators (serve, reception, set, attack, dig and block) were the variables considered in this study. In a first moment, performance indicators were used in a logistic model of set result, by binary logistic regression analysis. After finding the adjusted logistic model, the log-odds of winning the set were analysed according to game location and set number. The results showed that winning a set is significantly related to performance indicators (Chisquare(18)=660.97, padvantage at the beginning of the game (first set) and in the two last sets of the game (fourth and fifth sets), probably due to facilities familiarity and crowd effects. Different game actions explain these advantages and showed that to win the first set is more important to take risk, through a better performance in the attack and block, and to win the final set is important to manage the risk through a better performance on the reception. These results may suggest intra-game variation in home advantage and can be most useful to better prepare and direct the competition. Key pointsHome teams always have more probability of winning the game than away teams.Home teams have higher performance in reception, set and attack in the total of the sets.The advantage of home teams is more pronounced at the beginning of the game (first set) and in two last sets of the game (fourth and fifth sets) suggesting intra-game variation in home advantage.Analysis by sets showed that home teams have a better performance in the attack and block in the first set and in the reception in the third and fifth sets.

  13. [Effect of phlebodium decumanum and coenzyme Q10 on sports performance in professional volleyball players].

    Science.gov (United States)

    García Verazaluce, Juan José; Vargas Corzo, María Del Carmen; Aguilar Cordero, María José; Ocaña Peinado, Francisco; Sarmiento Ramírez, Álvaro; Guisado Barrilao, Rafael

    2014-10-03

    Physical training programmes are based on provoking transitory states of fatigue in order to induce super compensation by the biological systems involved in the activity, in order to improve the athlete's medium-long term performance. The administration of nutritional supplements with antioxidant and immunomodulatory properties, such as Phlebodium decumanum and coenzyme Q10, can be a very advantageous means of achieving recovery from the inflammation and tissue damage caused by the stress of prolonged, intense exercise. An experimental, longitudinal, double- blind experiment was conducted, with three randomised groups obtained from a sample of 30 male volleyball players (aged 22-32 years) at the University of Granada, with a high level of training (17 hours a week during the 6 months preceding the study). The effects were then evaluated of a month-long physical training programme, common to all the study groups, associated with the simultaneous administration of the following nutritional supplements: Phlebodium decumanum (4 capsules of 400 mg/capsule, daily), Experimental Group 1; Phlebodium decumanum (same dose and schedule as Group 1) plus coenzyme Q10 (4 capsules of 30 mg/ capsule, daily), Experimental Group 2; a placebo substance, Control Group. The following dependent blood variables were examined to assess the effects of the intervention on the basal immune and endocrine-metabolic profile: cortisol and interleukin-6, both related to the axis of exercise-induced stress; and lactic acid and ammonium, related essentially to the anaerobic metabolism of energy. All the study groups presented favourable adaptive changes with respect to the endocrine-metabolic and immune profile, as reflected by a significant decrease in the post-test concentrations of cortisol, interleukin 6, lactic acid and ammonium, compared to the values recorded before the physical activity with/without nutritional supplement, per protocol. The groups that achieved the most favourable profile

  14. Ankle Bracing, Fatigue, and Time to Stabilization in Collegiate Volleyball Athletes

    Science.gov (United States)

    Shaw, Megan Y; Gribble, Phillip A; Frye, Jamie L

    2008-01-01

    Context: Fatigue has been shown to disrupt dynamic stability in healthy volunteers. It is not known if wearing prophylactic ankle supports can improve dynamic stability in fatigued athletes. Objective: To determine the type of ankle brace that may be more effective at providing dynamic stability after a jump-landing task during normal and fatigued conditions. Design: Two separate repeated-measures analyses of variance with 2 within-subjects factors (condition and time) were performed for each dependent variable. Setting: Research laboratory. Patients or Other Participants: Ten healthy female collegiate volleyball athletes participated (age  =  19.5 ± 1.27 years, height  =  179.07 ± 7.6 cm, mass  =  69.86 ± 5.42 kg). Intervention(s): Athletes participated in 3 separate testing sessions, applying a different bracing condition at each session: no brace (NB), Swede-O Universal lace-up ankle brace (AB), and Active Ankle brace (AA). Three trials of a jump-landing task were performed under each condition before and after induced functional fatigue. The jump-landing task consisted of a single-leg landing onto a force plate from a height equivalent to 50% of each participant's maximal jump height and from a starting position 70 cm from the center of the force plate. Main Outcome Measure(s): Time to stabilization in the anterior-posterior (APTTS) and medial-lateral (MLTTS) directions. Results: For APTTS, a condition-by-time interaction existed (F2,18  =  5.55, P  =  .013). For the AA condition, Tukey post hoc testing revealed faster pretest (2.734 ± 0.331 seconds) APTTS than posttest (3.817 ± 0.263 seconds). Post hoc testing also revealed that the AB condition provided faster APTTS (2.492 ± 0.271 seconds) than AA (3.817 ± 0.263 seconds) and NB (3.341 ± 0.339 seconds) conditions during posttesting. No statistically significant findings were associated with MLTTS. Conclusions: Fatigue increased APTTS for the AA condition. Because the

  15. Physical and temporal characteristics of under 19, under 21 and senior male beach volleyball players.

    Science.gov (United States)

    Medeiros, Alexandre; Marcelino, Rui; Mesquita, Isabel; Palao, José Manuel

    2014-09-01

    This study aimed to assess the effects of age groups and players' role (blocker vs. defender specialist) in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19), 933 rallies from Under 21 (U21), and 1480 rallies from senior (senior) (Men's Swatch World Championships, 2010-2011) were observed using video match analysis. Cluster analysis was used to set teams' competitive levels and establish quality of opposition as "balanced", "moderate balanced" and "unbalanced" games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies) and physical (number of jumps and number of hits done by defenders and blockers) characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player's role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a) balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19) and U21; b) moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c) unbalanced games, no significant findings were shown. This study suggests differences in players' performances according to age group and players' role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics. Key PointsPlayer roles, quality of opposition

  16. [Influence of Ankle Braces on the Prevalence of Ankle Inversion Injuries in the Swiss Volleyball National League A].

    Science.gov (United States)

    Jaggi, J; Kneubühler, S; Rogan, S

    2016-06-01

    Ankle inversion is a common injury among volleyball players. The injury rate during a game is 2.1 times higher than during training. As a result, the preventive use of ankle braces is frequently observed in Swiss volleyball leagues. Studies have shown that ankle braces have a preventive effect on the prevalence of ankle inversion. In Switzerland there has been no investigation into the preventive use of braces and their influence on prevalence. For this reason, the goals of this study are 1) to determine when, why and by whom ankle braces are worn and 2) to evaluate the injury rate of users and non-users of ankle braces. A modified questionnaire was sent to 18 men's and women's teams of the Swiss National League A. The questionnaire included questions about injury rates and the circumstances of ankle inversion injuries. The data were statistically analysed with Microsoft Excel 2012 and SPSS Version 20. The overall response rate was 61 %, allowing data from 181 players to be analysed. 33 % (59 of 181) of the players used an ankle brace. There was a statistically significant difference in the prevalence of ankle inversion between users (12 injured) and non-users (8 injured) (p = 0.006). Wearing an ankle brace during training or during a game made no difference in the prevention of injuries (p = 0.356). More athletes were injured during training (n = 13) than during a game (n = 7). The results of the present study indicate that volleyball players preferably wear ankle braces to prevent injury. More than one third of the players in the study wore an ankle brace, 60 % for primary prevention and 40 % for secondary prevention due to a previous injury. The study shows that significantly more users than non-users of ankle braces were injured. This is contrary to literature. Furthermore it was shown that more injuries occur during training than during a game. This finding results from the fact that ankle braces were rarely worn during training. It is

  17. Body mass index and body fat percentage are associated with decreased physical fitness in adolescent and adult female volleyball players

    Directory of Open Access Journals (Sweden)

    Pantelis Theo Nikolaidis

    2013-01-01

    Full Text Available Background: The objectives of this study were to examine (a the prevalence of overweight/obesity, and (b the relationship between body mass index (BMI, body fat percentage (BF and physical fitness in adolescent and adult female volleyball players. Materials and Methods: Adolescent (n = 102, aged 15.2 ± 2.0 year and adult (n = 57, 25.9 ± 5.0 year players were examined for anthropometric characteristics and body composition, and performed the physical working capacity in heart rate 170 min -1 test, a force-velocity test, the Wingate anaerobic test (WAnT, sit-and-reach test (SAR, handgrip strength test (HST and countermovement vertical jump (CVJ. Results: Based on international BMI cut-off points, 27.5% (n = 28 of adolescent and 12.3% (n = 7 of adult participants were classified as overweight, with the prevalence of overweight being higher in girls than in women (χ2 = 4.90, P = 0.027. BMI was correlated with BF in both age groups (r = 0.72, P < 0.001 in girls; r = 0.75, P < 0.001 in women. Normal participants had superior certain physical and physiological characteristics than those who were overweight. For instance, normal girls and women had higher mean power during WAnT than their overweight counterparts (P = 0.003 and P = 0.009 respectively. Except for flexibility, BMI and BF were inversely related with physical fitness (e.g., BMI vs. HST r = -0.39, P < 0.001 in girls; BF vs. CVJ r = -0.45, P < 0.001 in women. Conclusion: The findings confirmed the negative effect of overweight and fatness on selected parameters of physical fitness. The prevalence of overweight in adolescent volleyball players was higher than in general population, which was a novel finding, suggesting that proper exercise interventions should be developed to target the excess of body mass in youth volleyball clubs.

  18. Nuclear energy in the oils sands

    International Nuclear Information System (INIS)

    Arsenault, J.E.

    2014-01-01

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  19. Nuclear energy in the oils sands

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, J.E.

    2014-09-15

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  20. Comparison between predicted and observed sand waves and sand banks in the North Sea

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; van den Brink, G.M.

    2001-01-01

    For the first time a prediction model of regular morphological patterns on the seabed was tested against observations of sand wave and sand bank occurrence in the entire North Sea. The model, which originates from first physical principles, predicts this occurrence via two dimensionless parameters

  1. MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

    Directory of Open Access Journals (Sweden)

    Lucimar Arruda Viana

    Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

  2. New Safety rules

    CERN Multimedia

    Safety Commission

    2008-01-01

    The revision of CERN Safety rules is in progress and the following new Safety rules have been issued on 15-04-2008: Safety Procedure SP-R1 Establishing, Updating and Publishing CERN Safety rules: http://cern.ch/safety-rules/SP-R1.htm; Safety Regulation SR-S Smoking at CERN: http://cern.ch/safety-rules/SR-S.htm; Safety Regulation SR-M Mechanical Equipment: http://cern.ch/safety-rules/SR-M.htm; General Safety Instruction GSI-M1 Standard Lifting Equipment: http://cern.ch/safety-rules/GSI-M1.htm; General Safety Instruction GSI-M2 Standard Pressure Equipment: http://cern.ch/safety-rules/GSI-M2.htm; General Safety Instruction GSI-M3 Special Mechanical Equipment: http://cern.ch/safety-rules/GSI-M3.htm. These documents apply to all persons under the Director General’s authority. All Safety rules are available at the web page: http://www.cern.ch/safety-rules The Safety Commission

  3. Analysis of jumping in the spike, block and set skills of female volleyball players

    Directory of Open Access Journals (Sweden)

    Valdir José Barbanti

    2007-09-01

    Full Text Available The purpose of this study was to quantify the different types of jump observed during volleyball matches. Jumps were classifi ed as block jumps, spike jumps or set jumps. The sample was 12 video-taped National Women’s Volleyball League matches. They were analyzed for specifi c types of jumping, such as spike jumps with and without approach; block jumps with and without step movement; and set jumps. Matches were recorded by two video cameras placed at the back court on each side of the net. Data were collected from the video tapes and each variable was recorded on a sheet of paper for subsequent statistical analysis. The results demonstrated that the highest mean numbers of any jump type per game performed by setters were of the type set jump: 39.0 ± 5.51, 57.3 ± 32.23 and 33 ± 8.49, in games of 3, 4 and 5 sets respectively. For outside hitter players the greatest number of jumps were of the type spike jump with approach, in games of 3, 4 and 5 sets respectively (20.44 ± 5.15, 29.23 ± 7.16 and 35.67 ± 13.21. Middle block players exhibited mean values for block jumps with step movements of 17.04 ± 8.19, 29.9 ± 10.85 and 34.25 ± 5.62, respectively. These results indicate that there was no difference between outside hitters and middle block players in 5-set games in terms of numbers of spike jumps with approach. There was a significant difference between setters and outside hitters in numbers of spike jumps without approach, in games of 3 and 5 sets. There were no differences between any of the positions in block jumps with step in games of 3, 4 or 5 sets. There was no difference between middle block and outside hitter players in terms of set jumps. It was concluded that setters exhibited the highest average number of set jumps per game, outside hitters exhibited the highest mean number of spike jumps with approach and middle block players exhibited highest mean numbers per match of block jumps with step movement. ABSTRACT O presente

  4. Action Rules Mining

    CERN Document Server

    Dardzinska, Agnieszka

    2013-01-01

    We are surrounded by data, numerical, categorical and otherwise, which must to be analyzed and processed to convert it into information that instructs, answers or aids understanding and decision making. Data analysts in many disciplines such as business, education or medicine, are frequently asked to analyze new data sets which are often composed of numerous tables possessing different properties. They try to find completely new correlations between attributes and show new possibilities for users.   Action rules mining discusses some of data mining and knowledge discovery principles and then describe representative concepts, methods and algorithms connected with action. The author introduces the formal definition of action rule, notion of a simple association action rule and a representative action rule, the cost of association action rule, and gives a strategy how to construct simple association action rules of a lowest cost. A new approach for generating action rules from datasets with numerical attributes...

  5. 18 CFR 385.104 - Rule of construction (Rule 104).

    Science.gov (United States)

    2010-04-01

    ... Definitions § 385.104 Rule of construction (Rule 104). To the extent that the text of a rule is inconsistent with its caption, the text of the rule controls. [Order 376, 49 FR 21705, May 23, 1984] ...

  6. Heavy mineral concentration from oil sand tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chachula, F.; Erasmus, N. [Titanium Corp. Inc., Regina, SK (Canada)

    2008-07-01

    This presentation described a unique technique to recover heavy minerals contained in the froth treatment tailings produced by oil sand mining extraction operations in Fort McMurray, Alberta. In an effort to process waste material into valuable products, Titanium Corporation is developing technology to recover heavy minerals, primarily zircon, and a portion of bitumen contained in the final stage of bitumen processing. The process technology is being developed to apply to all mined oil sands operations in the Fort McMurray region. In 2004, Titanium Corporation commissioned a pilot research facility at the Saskatchewan Research Council to test dry oil sands tailings. In 2005, a bulk sampling pilot plant was connected to the fresh oil sands tailings pipeline on-site in Fort McMurray, where washed sands containing heavy minerals were processed at a pilot facility. The mineral content in both deposited tailings and fresh pipeline tailings was assessed. Analysis of fresh tailings on a daily basis identified a constant proportion of zircon and higher levels of associated bitumen compared with the material in the deposited tailings. The process flow sheet design was then modified to remove bitumen from the heavy minerals and concentrate the minerals. A newly modified flotation process was shown to be a viable processing route to recover the heavy minerals from froth treatment tailings. 8 refs., 9 tabs., 12 figs.

  7. A Improved Seabed Surface Sand Sampling Device

    Science.gov (United States)

    Luo, X.

    2017-12-01

    In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

  8. Sand filter clogging by septic tank effluent.

    Science.gov (United States)

    Spychała, M; Błazejewski, R

    2003-01-01

    The aim of this study was to characterise conditions and factors affecting fine sand clogging by septic tank effluent on the basis of physical modelling. The physical model consisted of 12 sand columns dosed with sewage from one household (5 persons), preliminary treated in a septic tank. Hydraulic loadings of the sand filters were equal to 82 mm/d. The mean discharge from sand columns, measured as the effluent volume collected during 10 minutes, decreased significantly over the experiment period from 34 cm3/min in August 2000 to 20 cm3/min in August 2001 at the same temperature of about 20 degrees C. First the columns clogged almost completely after 480 days in December 2001, however six columns had remained unclogged till the end of the experiment (March 2002). The temperature had a significant impact on hydraulic conductivity. A vertical distribution of accumulated mass and biomass was investigated in partly clogged sand. Microscopic survey of the clogging layer showed a presence of live micro-organisms, residuals of dead micro-organisms, particularly pieces of small animal armour and many fibres. These particles accelerated the accumulation of solids in the upper clogging layer. The study indicated that temperature impact on the filter hydraulic conductivity was more significant for biological activity, than for sewage viscosity.

  9. The behavior of gaseous iodine in sand

    International Nuclear Information System (INIS)

    Takahashi, Kanji

    1974-01-01

    Radioactive iodine gas was passed through 10 different sands collected at rivers and hills. The relation between the amount of the loaded gas and the amount of adsorbed gas was determined at room temperature, 50 -- 60 0 C, and 90 -- 100 0 C under humidity of 2 sand. This amount was about 1 -- 3 times as much as that of monomolecular membrane adsorption, 0.2 -- 0.3 μg/cm 2 . The decrease of adsorption amount that accompanies the increase of humidity is attributable to the decrease of effective surface area of sand due to the presence of water. The transport of iodine in sand was studied by passing gaseous iodine through a glass tubing packed with sand. The distribution in the flow direction of iodine indicated that the ease of desorption depends upon the situation of adsorption. Easily desorbed case was named Henry type adsorption. Hardly desorbed case was named absorption type. Discussion is made on experimental results. (Fukutomi, T.)

  10. Mitigating in situ oil sands carbon costs

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

    2008-10-15

    Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

  11. The influence of expertise on brain activation of the action observation network during anticipation of tennis and volleyball serves

    Science.gov (United States)

    Balser, Nils; Lorey, Britta; Pilgramm, Sebastian; Naumann, Tim; Kindermann, Stefan; Stark, Rudolf; Zentgraf, Karen; Williams, A. Mark; Munzert, Jörn

    2014-01-01

    In many daily activities, and especially in sport, it is necessary to predict the effects of others' actions in order to initiate appropriate responses. Recently, researchers have suggested that the action–observation network (AON) including the cerebellum plays an essential role during such anticipation, particularly in sport expert performers. In the present study, we examined the influence of task-specific expertise on the AON by investigating differences between two expert groups trained in different sports while anticipating action effects. Altogether, 15 tennis and 16 volleyball experts anticipated the direction of observed tennis and volleyball serves while undergoing functional magnetic resonance imaging (fMRI). The expert group in each sport acted as novice controls in the other sport with which they had only little experience. When contrasting anticipation in both expertise conditions with the corresponding untrained sport, a stronger activation of AON areas (SPL, SMA), and particularly of cerebellar structures, was observed. Furthermore, the neural activation within the cerebellum and the SPL was linearly correlated with participant's anticipation performance, irrespective of the specific expertise. For the SPL, this relationship also holds when an expert performs a domain-specific anticipation task. Notably, the stronger activation of the cerebellum as well as of the SMA and the SPL in the expertise conditions suggests that experts rely on their more fine-tuned perceptual-motor representations that have improved during years of training when anticipating the effects of others' actions in their preferred sport. The association of activation within the SPL and the cerebellum with the task achievement suggests that these areas are the predominant brain sites involved in fast motor predictions. The SPL reflects the processing of domain-specific contextual information and the cerebellum the usage of a predictive internal model to solve the anticipation

  12. The influence of expertise on brain activation of the action observation network during anticipation of tennis and volleyball serves.

    Science.gov (United States)

    Balser, Nils; Lorey, Britta; Pilgramm, Sebastian; Naumann, Tim; Kindermann, Stefan; Stark, Rudolf; Zentgraf, Karen; Williams, A Mark; Munzert, Jörn

    2014-01-01

    In many daily activities, and especially in sport, it is necessary to predict the effects of others' actions in order to initiate appropriate responses. Recently, researchers have suggested that the action-observation network (AON) including the cerebellum plays an essential role during such anticipation, particularly in sport expert performers. In the present study, we examined the influence of task-specific expertise on the AON by investigating differences between two expert groups trained in different sports while anticipating action effects. Altogether, 15 tennis and 16 volleyball experts anticipated the direction of observed tennis and volleyball serves while undergoing functional magnetic resonance imaging (fMRI). The expert group in each sport acted as novice controls in the other sport with which they had only little experience. When contrasting anticipation in both expertise conditions with the corresponding untrained sport, a stronger activation of AON areas (SPL, SMA), and particularly of cerebellar structures, was observed. Furthermore, the neural activation within the cerebellum and the SPL was linearly correlated with participant's anticipation performance, irrespective of the specific expertise. For the SPL, this relationship also holds when an expert performs a domain-specific anticipation task. Notably, the stronger activation of the cerebellum as well as of the SMA and the SPL in the expertise conditions suggests that experts rely on their more fine-tuned perceptual-motor representations that have improved during years of training when anticipating the effects of others' actions in their preferred sport. The association of activation within the SPL and the cerebellum with the task achievement suggests that these areas are the predominant brain sites involved in fast motor predictions. The SPL reflects the processing of domain-specific contextual information and the cerebellum the usage of a predictive internal model to solve the anticipation task.

  13. Effect of eight weeks of upper-body plyometric training during the competitive season on professional female volleyball players.

    Science.gov (United States)

    Valades, David; Palao, José M; Femia, Pedro; Ureña, Aurelio

    2017-07-25

    The purpose of this study was to assess the effect of incorporating specific upper-body plyometric training for the spike into the competitive season of a women's professional volleyball team. A professional team from the Spanish first division participated in the study. An A-B-A' quasi-experimental design with experimental and control groups was used. The independent variable was the upper-body plyometric training for eight weeks during the competitive season. The dependent variables were the spiked ball's speed (Km/h); the player's body weight (Kg), BMI (Kg/m2), and muscle percentage in arms (%); 1 repetition maximum (1RM) in the bench press (Kg); 1RM in the pullover (Kg); and overhead medicine ball throws of 1, 2, 3, 4, and 5 kg (m). Inter-player and inter-group statistical analyses of the results were carried out (Wilcoxon test and linear regression model). The experimental group significantly improved their spike speed 3.8% from phase A to phase B, and they maintained this improvement after the retention phase. No improvements were found in the control group. The experimental group presented a significant improvement from phase A to phase B in dominant arm muscle area (+10.8%), 1RM for the bench press (+8.41%), 1RM for the pullover (+14.75%), and overhead medicine ball throws with 1 kg (+7.19%), 2 kg (+7.69%), and 3 kg (+5.26%). The control group did not present differences in these variables. Data showed the plyometric exercises that were tested could be used by performance-level volleyball teams to improve spike speed. The experimental group increased their upper-body maximal strength, their power application, and spike speed.

  14. Breast Injuries in Female Collegiate Basketball, Soccer, Softball and Volleyball Athletes: Prevalence, Type and Impact on Sports Participation.

    Science.gov (United States)

    Smith, Laura J; Eichelberger, Tamara D; Kane, Edward J

    2018-01-01

    In 2015-2016, over 214,000 female athletes competed at the collegiate level in the United States (U.S.). The National Collegiate Athletic Association (NCAA) collects injury data; however, breast-related injuries do not have a specific reporting category. The exact sequelae of breast injury are unknown; however, a relationship between breast injury and fat necrosis, which mimics breast carcinoma, is documented outside of sports participation. Breast injuries related to motor vehicle collisions, seatbelt trauma, and blunt trauma have been reported. For these reasons, it is important to investigate female breast injuries in collegiate sports. The objectives of this study are to report the prevalence of self-reported breast injuries in female collegiate athletes, explore injury types and treatments, and investigate breast injury reporting and impact on sports participation. A cross-sectional study of female collegiate athletes at four U.S. universities participating in basketball, soccer, softball, or volleyball. Main outcome measure was a questionnaire regarding breast injuries during sports participation. Almost half of the 194 participants (47.9%) reported a breast injury during their collegiate career, less than 10% reported their injury to health personnel with 2.1% receiving treatment. Breast injuries reported by breast injuries reported by sport include softball (59.5%), basketball (48.8%), soccer (46.7%), and volleyball (34.6%). The long-term effects and sequelae of breast injuries reported by female collegiate athletes during sport play are unknown. Nearly 50% of participants had a breast injury during sports activities. Although 18.2% indicated that breast injury affected sports participation, only 9.6% of the injuries were reported to medical personnel with 2.1% receiving treatment.

  15. Analysis of the profile, areas of action and abilities of Brazilian sports physical therapists working with soccer and volleyball.

    Science.gov (United States)

    Silva, Anderson A; Bittencourt, Natália F N; Mendonça, Luciana M; Tirado, Marcella G; Sampaio, Rosana F; Fonseca, Sérgio T

    2011-01-01

    To analyze the profile of Brazilian physical therapists working with soccer and volleyball professional teams, by verifying their level of education (graduate or undergraduate), as well as their role and insertion within the interdisciplinary team. Structured questionnaires were administered to forty-nine physical therapists working at soccer, volleyball clubs and Brazilian national teams. These questionnaires provided data on social demographic, characteristics of the work environment and organization of clinical practice and its domains. From the 49 participants in this study only five were female. Mean age of all participants was 32.2 years. The majority of the sports physical therapists had specialization degrees in different areas (78.2%), were hired through referral (78.2%), worked more than 8 hours a day or were exclusively dedicated to their clubs (80.0%) and earned seven to ten Brazilian minimal wages (58.2%). They reported to have participation in the domains of emergency care (87.3%), prevention (92.7%), functional rehabilitation (98.2%) and return to competition (100%). They had interdisciplinary relationships with physical educators during functional rehabilitation programs (70.9%) and with physicians in the decision process of return to activity after rehabilitation (74.5%) and on the veto of an athlete to take part in practices or matches (63.6%). Therapists also complained of threats to their professional autonomy, specially directed by the team's physician. There is still a need to invest in continuing education of sports physical therapists with the objective to improve their educational level and to strengthen their professional autonomy.

  16. The influence of expertise on brain activation of the Action Observation Network during anticipation of tennis and volleyball serves

    Directory of Open Access Journals (Sweden)

    Nils eBalser

    2014-08-01

    Full Text Available In many daily activities, and especially in sport, it is necessary to predict the effects of others’ actions in order to initiate appropriate responses. Recently, researchers have suggested that the action–observation network (AON including the cerebellum plays an essential role during such anticipation, particularly in sport expert performers. In the present study, we examined the influence of task-specific expertise on the AON by investigating differences between two expert groups trained in different sports while anticipating action effects. Altogether, 15 tennis and 16 volleyball experts anticipated the direction of observed tennis and volleyball serves while undergoing functional magnetic resonance imaging (fMRI. The expert group in each sport acted as novice controls in the other sport with which they had only little experience. When contrasting anticipation in both expertise conditions with the corresponding untrained sport, a stronger activation of AON areas (SPL, SMA, and particularly of cerebellar structures, was observed. Furthermore, the neural activation within the cerebellum and the SPL was linearly correlated with participant’s anticipation performance, irrespective of the specific expertise. For the SPL, this relationship also holds when an expert performs a domain-specific anticipation task. Notably, the stronger activation of the cerebellum as well as of the SMA and the SPL in the expertise conditions suggests that experts rely on their more fine-tuned perceptual-motor representations that have improved during years of training when anticipating the effects of others’ actions in their preferred sport. The association of activation within the SPL and the cerebellum with the task achievement suggests that these areas are the predominant brain sites involved in fast motor predictions. The SPL reflects the processing of domain-specific contextual information and the cerebellum the usage of a predictive internal model to

  17. Visual search behaviours and verbal reports during film-based and in situ representative tasks in volleyball.

    Science.gov (United States)

    Afonso, José; Garganta, Júlio; McRobert, Allistair; Williams, Mark; Mesquita, Isabel

    2014-01-01

    Several researchers have explored the processes underlying perceptual-cognitive expertise, mainly using film-based studies. However, few have compared the extent to which data from film-based settings differ from those obtained through in situ collection. This gap in the literature is a relevant concern, since scientific research is used to provide guidance for designing training programmes. In this paper, eye movement recording and verbal reports of thinking were combined to explore the processes underpinning skilled performance in a representative volleyball task involving both film-based and in situ data collection. Nine volleyball players performed as backcourt defenders while wearing an eye-tracking device and providing verbal reports of thinking after each sequence. A number of significant differences were observed between the data gathered under film-based and in situ conditions. Namely, in the in situ condition participants employed longer fixations (728.11 ± 129.27 ms) than in the film condition (659.57 ± 178.06 ms), and there were differences in the nature of the fixation locations. With respect to verbal reports, participants exhibited superior level of sophistication in the in situ condition (2.57 ± 0.50 vs. 2.30 ± 0.84 in the film condition), while denoting a greater concern with the opponents under this condition (1.00 ± 0.73) than in the film condition (0.59 ± 0.60). These differences emerged despite task design and constraints being highly similar. No differences were apparent in the number of gaze fixations and fixation locations across conditions or in the number of verbalised condition concepts. Although exploratory, our data suggest that the mechanisms underpinning skilled decision-making in sports differ between film-based and in situ conditions.

  18. Relationship of long-term macronutrients intake on anabolic-catabolic hormones in female elite volleyball players.

    Science.gov (United States)

    Mielgo Ayuso, Juan; Zourdos, Michael C; Urdampilleta, Aritz; Calleja González, Julio; Seco, Jesús; Córdova, Alfredo

    2017-10-24

    Specific macronutrient distribution and training can alter acute and chronic hormone behavior and, subsequently, sport performance. The main aim was to examine relationships between dietary intake and anabolic/catabolic hormone response in elite female volleyball players during a 29-week season. Twenty-two elite female volleyballers (26.4 ± 5.6 years; 178 ± 9 cm; 67.1 ± 7.5 kg) had dietary intake (seven-day dietary recall and food frequency questionnaire), blood concentration of anabolic/catabolic hormones concentration, physical performance, and body composition assessed at four time points: a) T1: baseline/pre-testing; b) T2: eleven weeks after T1; c) T3: ten weeks after T2; and d) T4: eight weeks after T3. Hormones evaluated were: total testosterone (TT), free testosterone (FT) adrenocorticotropic hormone (ACTH), and cortisol (C), along with hormone ratios. Positive correlations were observed between carbohydrate/protein ratio with ΔFT (r = 0.955; p 0.05) in body mass or body mass index at any time point, and the sum of six skinfolds improved (p < 0.05) from T1 (86.5 ± 6.9 mm) to T4 (75.2 ± 5.6 mm) as did muscle mass (T1: 28.9 ± 0.7 kg vsT4: 30.1 ± 0.8 kg). Vertical jump, spike-jump and speed improved (p < 0.05) from T1 to T4. A high carbohydrate/protein ratio was associated with positive changes in anabolism, while high protein and low carbohydrates (CHO) were associated with an attenuated anabolic response.

  19. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    is expanding our current understanding and outline the areas of advancement needed in the future. Presentation is made of current models for wind driven detachment/entrainment and the transport rates of sand and dust, including the effects of contact induced grain electrification. This ubiquitous phenomenon...... can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

  20. Thermoluminescent dosimetric properties of Descalvado sand

    International Nuclear Information System (INIS)

    Teixeira, M.I.; Caldas, L.V.E.

    2006-01-01

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ( 60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  1. Development tendencies of moulding and core sands

    Directory of Open Access Journals (Sweden)

    Stanislaw M. Dobosz1

    2011-11-01

    Full Text Available Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

  2. Thermoluminescent dosimetric properties of Descalvado sand

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M.I.; Caldas, L.V.E

    2006-07-01

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  3. A Threshold Continuum for Aeolian Sand Transport

    Science.gov (United States)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  4. Gasification of oil sand coke: review

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

    1998-08-01

    The production of synthetic crude from the tar sands in Western Canada has been steadily increasing. Most of the delayed coke produced by Suncor is combusted on site, whereas all fluid coke produced by Syncrude is stockpiled.The database on the chemical and physical properties of the oil sand coke, including the composition and fusion properties of the mineral matter, has been established. The reactivity of the coke was determined by oxygen chemisorption, fixed bed and fluid bed bench scale gasification and pilot plant gasification. The reactivity of the oil sand coke for gasification is rather low and comparable to high rank coals, such as anthracite. Slurrability tests revealed that a solid concentration in water, approaching 70 wt%, can be achieved. Gasification is the front runner among clean technologies for the conversion of carbonaceous solids to useful products. Several commercial gasifiers are available to cover the wide range of severity. Because of the low reactivity of oil sands coke, high severity conditions are required to achieve high gasification conversion. Such conditions can be attained in entrained bed gasifiers. Gasifiers employing both dry and slurry feeding systems are suitable. A high efficiency, low SO{sub x} and NO{sub x} emissions, as well as a low solid waste production are among the key advantages of the gasification technology compared with thecompeting technologies. Commercial gasification of oil sands coke is delayed because of the availability of natural gas on the site of the upgrading plants. Potential for the transportation of the oil sand coke to USA for electricity generation using the integrated gasification combined-cycle (IGCC) technology was evaluated. 27 refs., 17 figs., 9 tabs.

  5. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    A model is presented of the development of the size distribution of sand while it is transported from a source to a deposit. The model provides a possible explanation of the log-hyperbolic shape that is frequently found in unimodal grain size distributions in natural sand deposits, as pointed out......-distribution, by taking into account that individual grains do not have the same travel time from the source to the deposit. The travel time is assumed to be random so that the wear on the individual grains vary randomly. The model provides an interpretation of the parameters of the NIG-distribution, and relates the mean...

  6. Creating fluid injectivity in tar sands formations

    Science.gov (United States)

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2010-06-08

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

  7. Log-inject-log in sand consolidation

    International Nuclear Information System (INIS)

    Murphy, R.P.; Spurlock, J.W.

    1977-01-01

    A method is described for gathering information for the determination of the adequacy of placement of sand consolidating plastic for sand control in oil and gas wells. The method uses a high neutron cross-section tracer which becomes part of the plastic and uses pulsed neutron logging before and after injection of the plastic. Preferably, the method uses lithium, boron, indium, and/or cadmium tracers. Boron oxide is especially useful and can be dissolved in alcohol and mixed with the plastic ingredients

  8. Oil sand synfuel production using nuclear energy

    International Nuclear Information System (INIS)

    Barnert, H.

    1984-10-01

    The importance of oil sand as a primary energy carrier is illustrated. The oil sand mining project 'synfuel' in Fort McMurray, Alberta, Canada, is described. On the basis of a layout of an In-situ-process different possibilities of introducing nuclear energy to the process are described. This leads to an increase of the product yield, leading finally to a doubling of the energy output compared to the reference layout. The introduction of nuclear energy contributes to the reduction of emissions, in particular to the emission of carbon dioxide in the conversion process. (orig.)

  9. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  10. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  11. Sand control systems used in completing wells

    Directory of Open Access Journals (Sweden)

    Gabriel Wittenberger

    2005-12-01

    Full Text Available Expandable Tubular Technology is transforming the face of well completion and construction. This technology provides: a substantially higher hydrocarbon production rates from the reservoir, a reduced well drilling and construction costs, new possibilities for previously unreachable or uneconomic reservoirs, and step a change towards the single diameter well. ESS (Expandable Sand Screen has an unrivalled performance worldwide for delivering a reliable sand control in a wide range of applications. Well costs typically cut by over 20 %, and the productivity increases up to 70 %.

  12. Experimental perforation of tubing with a hydraulic sand jet

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, Yu V

    1970-01-01

    A series of field tests has shown that perforation with a hydraulic sand jet improves the quality of well completion. The sand jet does not crack the cement sheath or the casing, and the perforations are larger and deeper than perforations formed by explosive charges. Fluid circulation during sand jet perforation can safely be stopped for at least 10 min. Water containing a surfactant can be used as a sand carrier. Sand jet perforation allows successful completion of wells cased by 2 tubing strings. Sand jet perforation can be used to clean the borehole well and to remove foreign objects from the well.

  13. Physical therapists' role in prevention and management of patellar tendinopathy injuries in youth, collegiate, and middle-aged indoor volleyball athletes

    Science.gov (United States)

    Kulig, Kornelia; Noceti-DeWit, Lisa M.; Reischl, Stephen F.; Landel, Rob F.

    2015-01-01

    Patellar tendinopathy is highly prevalent in all ages and skill levels of volleyball athletes. To illustrate this, we discuss the clinical, biomechanical, and ultrasound imaging presentation and the intervention strategies of three volleyball athletes at different stages of their athletic career: youth, middle-aged, and collegiate. We present our examination strategies and interpret the data collected, including visual movement analysis and dynamics, relating these findings to the probable causes of their pain and dysfunction. Using the framework of the EdUReP concept, incorporating Education, Unloading, Reloading, and Prevention, we propose intervention strategies that target each athlete's specific issues in terms of education, rehabilitation, training, and return to sport. This framework can be generalized to manage patellar tendinopathy in other sports requiring jumping, from youth to middle age, and from recreational to elite competitive levels. PMID:26537811

  14. Can psychological well-being scales and hormone levels be used to predict acute performance of anaerobic training tasks in elite female volleyball players?

    Science.gov (United States)

    Mielgo-Ayuso, Juan; Zourdos, Michael C; Clemente-Suárez, Vicente J; Calleja-González, Julio; Shipherd, Amber M

    2017-10-15

    The purpose of this study was to examine relationships between pre-training psychological well-being assessment scales (General Health Questionnaire-28-GHQ-28, Competitive State Anxiety Inventory-2-CSAI-2, Sport Competition Anxiety Test-SCAT, State-Trait Anxiety Inventory-S-STAI-S, Oviedo Sleep Questionnaire-OSQ and Psychological Characteristics Related to Sport Performance-PCSP), and pre-training stress hormone concentrations (cortisol-C, total testosterone-TT, free testosterone-FT, adrenocorticotropic hormone-ACTH and testosterone/cortisol-T/C ratios), on acute neuromuscular performance (ANP) in female volleyballers. Forty elite female volleyballers (27±4yrs.; 178.3±8.5cm; 67.9±7.2kg) participated. Bivariate correlations were performed between psychological assessments and hormone levels with ANP. All psychological scales presented at least one significant (pvolleyballers than pre-training stress hormone concentrations. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Influence of a sport-specific training background on vertical jumping and throwing performance in young female basketball and volleyball players.

    Science.gov (United States)

    Battaglia, G; Paoli, A; Bellafiore, M; Bianco, A; Palma, A

    2014-10-01

    The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. Thirty-one healthy adolescent girls, of which 11 age-matched control subjects [C], 10 basketballers (BP) and 10 volleyballers (VP) participated to the study. The throwing performance was assessed by seated backward overhead ball throw (SBOMBT) and seated chest pass throw (SCPT) using a 3-kg rubber medicine ball. Instead, the vertical jumping performance was evaluated by squat jump (SJ) and countermovement jump with (CMJ-AS) and without arm swing (CMJ) using Optojump system (Microgate srl, Italy). During SJ and CMJ with and without arm swing VP group showed a higher vertical jump performance than BP and C ones. In particular we showed that VP exhibited a higher flight time and jump height than C (Pbasketball athletes' maximal power compared to age-matched control subjects.

  16. Technical rules in law

    Energy Technology Data Exchange (ETDEWEB)

    Debelius, J

    1978-08-01

    An important source of knowledge for technical experts is the state of the art reflected by catalogues of technical rules. Technical rules may also achieve importance in law due to a legal transformation standard. Here, rigid and flexible reference are controversial with regard to their admissibility from the point of view of constitutional law. In case of a divergence from the generally accepted technical rules, it is assumed - refutably - that the necessary care had not been taken. Technical rules are one out of several sources of information; they have no normative effect. This may result in a duty of anyone applying them to review the state of technology himself.

  17. Technical rules in law

    International Nuclear Information System (INIS)

    Debelius, J.

    1978-01-01

    An important source of knowledge for technical experts is the state of the art reflected by catalogues of technical rules. Technical rules may also achieve importance in law due to a legal transformation standard. Here, rigid and flexible reference are controversial with regard to their admissibility from the point of view of constitutional law. In case of a divergence from the generally accepted technical rules, it is assumed - refutably - that the necessary care had not been taken. Technical rules are one out of several sources of information; they have no normative effect. This may result in a duty of anyone applying them to review the state of technology himself. (orig.) [de

  18. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  19. Comparison of whole-body vibration exercise and plyometric exercise to improve isokinetic muscular strength, jumping performance and balance of female volleyball players

    OpenAIRE

    Kim, Yong-Youn; Park, Si-Eun

    2016-01-01

    [Purpose] The purpose of this study was to assess the effect of whole-body vibration exercise and plyometric exercise on female volleyball players. [Subjects and Methods] Subjects were randomly allocated to two exercise groups (whole-body vibration exercise group and plyometric exercise group). The exercise was conducted three times each week for 8 weeks. Isokinetic muscular strength, jumping performance, and balance were measured before starting the exercise and after finishing the 8 weeks o...

  20. Differences in rotations between the winning and losing teams at the youth European volleyball championships for girls [Změny v rotacích mezi vyhrávajícími a prohrávajícími týmy na juniorských mistrovstvích Evropy ve volejbalu dívek

    Directory of Open Access Journals (Sweden)

    Marko Zadražnik

    2009-12-01

    Full Text Available BACKGROUND: Researchers of the game of volleyball often study the differences that separate the winning and losing teams. Namely, the volleyball game runs in two complexes (K1 - game after receive of serve: serve - receipt of serve - setting the attack - attack; K2 - game after own serve: serve - block - defence - counter attack, in addition the players have to rotate in accordance with the rules of the game of volleyball. Playing situations in six rotations do not equally correlate to K1 and K2 in their tactical aspect, nor are they of the same difficulty. OBJECTIVES: The study examined whether there are statistically significant differences in the phases of a volleyball game between the winners and losers for each of the six volleyball rotations separately. Differences in individual rotations between winning and losing teams were examined. For rotations with statistically significant differences between the teams, the phases that determine those differences the most were also researched. METHODS: The study was carried out at the European youth volleyball championships for women. Twenty games were analysed, a five level scale was used to evaluate the successfulness of the game for 98 under 18 years old women players. Six phases of the volleyball game were analysed: serve, receipt of serve, attack in K1, attack in K2, block and defence (attack receipt. A criterion variable was represented with each individual rotation. Simple descriptive statistical parameters were calculated together with six canonical discriminant analyses, one for each of the volleyball rotations. RESULTS: The results of canonical discriminatory analysis revealed that four out of six volleyball rotations were statistically significant at the level of p < 0.05 (rotation 1 = 0.02; rotation 2 = 0.00; rotation 3 = 0.00; rotation 6 = 0.04. It is interesting to notice that different game phases show the largest projection of discriminatory function exactly in the rotations with

  1. A cost comparison of nuclear and fossil power for the Alberta tar sands

    International Nuclear Information System (INIS)

    Sochaski, R.O.; Smith, D.W.

    1977-04-01

    One technique envisaged for commercial development of the Alberta tar sands is in-situ removal of bitumen by injection of steam into the formation at high temperature and pressure. The 3000 MW of thermal power required for a typical 20 Gg/d plant could be supplied by a nuclear reactor. Accordingly, an economic comparison was made between a CANDU organic-cooled reactor and a conventional coal-fired station, using a variety of financial ground rules. This analysis shows that for debt-financed cases, nuclear power has essentially no economic competition from coal. For equity cases, the competitive position of a coal-fired station is heavily dependent on the cost of coal delivered to the tar sands area, discount rate, amortization period and inflation rate. (author)

  2. Study of greenhouse gases reduction alternatives for the exploitation of non conventional oil sands in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Bouchonneau, Deborah [Institut Francais du Petrole (IFP), Paris (France)

    2008-07-01

    High energy prices and greenhouse gases reduction represent the main challenges the current worldwide energetic situation has to face. As a consequence, paradox strategies can be highlighted: oil prices are sufficiently high to exploit non conventional oil resources, like extra heavy oils and oil sands. But the production of these resources emits larger GHG than the conventional oil path and implies other major environmental issues (water management, risks of soil pollution, destruction of the boreal forest), incompatible with the rules validated by the protocol of Kyoto. At the light of the new greenhouse gases reduction regulation framework announced by the Canadian Federal government, this work focuses on the study of greenhouse gases reduction alternatives applied to the non conventional oil sands exploitation in Canada. (author)

  3. Changes induced by diet and nutritional intake in the lipid profile of female professional volleyball players after 11 weeks of training

    Science.gov (United States)

    2013-01-01

    Background The relationship between cardiovascular disease and lipid profile is well known. Apart from a heart-healthy diet, exercise is the primary factor that can modify this lipid-associated cardiovascular risk. The aim of the study was to evaluate potential changes in the levels of triglycerides, total cholesterol (TC), low-density lipoprotein-cholesterol (LDLc), and high-density lipoprotein-cholesterol (HDLc), as well as atherogenic indices (TC/HDLc and LDLc/HDLc), and also to analyse the diet over 11 weeks of training in female professional volleyball players. Methods The lipid profile of 22 female professional volleyball players was analysed on Day T0 (pre-preseason) and Day T11 (after 11 weeks of training). The consumption of fats by the players was estimated using a food frequency questionnaire, confirmed by seven days of full dietary records. Results By the end of the study, the LDLc levels and both atherogenic indices of the players had decreased (p volleyball players during the first 11 weeks of training in the season was heart healthy, because their lipid profile improved, despite an inadequate intake of fats. PMID:24330488

  4. Test-retest reliability and agreement of the SPI-Questionnaire to detect symptoms of digital ischemia in elite volleyball players.

    Science.gov (United States)

    van de Pol, Daan; Zacharian, Tigran; Maas, Mario; Kuijer, P Paul F M

    2017-06-01

    The Shoulder posterior circumflex humeral artery Pathology and digital Ischemia - questionnaire (SPI-Q) has been developed to enable periodic surveillance of elite volleyball players, who are at risk for digital ischemia. Prior to implementation, assessing reliability is mandatory. Therefore, the test-retest reliability and agreement of the SPI-Q were evaluated among the population at risk. A questionnaire survey was performed with a 2-week interval among 65 elite male volleyball players assessing symptoms of cold, pale and blue digits in the dominant hand during or after practice or competition using a 4-point Likert scale (never, sometimes, often and always). Kappa (κ) and percentage of agreement (POA) were calculated for individual symptoms, and to distinguish symptomatic and asymptomatic players. For the individual symptoms, κ ranged from "poor" (0.25) to "good" (0.63), and POA ranged from "moderate" (78%) to "good" (97%). To classify symptomatic players, the SPI-Q showed "good" reliability (κ = 0.83; 95%CI 0.69-0.97) and "good" agreement (POA = 92%). The current study has proven the SPI-Q to be reliable for detecting elite male indoor volleyball players with symptoms of digital ischemia.

  5. Iron supplementation prevents a decline in iron stores and enhances strength performance in elite female volleyball players during the competitive season.

    Science.gov (United States)

    Mielgo-Ayuso, Juan; Zourdos, Michael C; Calleja-González, Julio; Urdampilleta, Aritz; Ostojic, Sergej

    2015-06-01

    The primary aim of this study was to examine the effects of 11 weeks of iron supplementation on hematological and strength markers in elite female volleyball players. Twenty-two volleyball players (aged 27.0 ± 5.6 years) from 2 Spanish First National League teams participated and were counterbalanced into 1 of 2 groups based upon iron status: (i) control group (CG, n = 11); or (ii) iron treatment group (ITG, n = 11), which received 325 mg/day of ferrous sulphate daily. Subjects performed their team's regimen of training or match play every day. Both groups were tested for hematological and strength levels at 2 points: (i) baseline (T0, before preseason) and (ii) 11 weeks later (T11, post-testing). Hematological parameters were serum iron (sFe), serum ferritin (FER), transferrin saturation index (TSI), and hemoglobin (Hb); strength assessments were bench press, military press, half-squat, power clean, clean and jerk, and pull-over. CG experienced a significant decrease (p 0.05). Consequently, in ITG all hematological parameters were significantly greater (p volleyball players during the competitive season.

  6. Changes induced by diet and nutritional intake in the lipid profile of female professional volleyball players after 11 weeks of training.

    Science.gov (United States)

    Mielgo-Ayuso, Juan; Collado, Pilar S; Urdampilleta, Aritz; Martínez-Sanz, José Miguel; Seco, Jesús

    2013-12-11

    The relationship between cardiovascular disease and lipid profile is well known. Apart from a heart-healthy diet, exercise is the primary factor that can modify this lipid-associated cardiovascular risk. The aim of the study was to evaluate potential changes in the levels of triglycerides, total cholesterol (TC), low-density lipoprotein-cholesterol (LDLc), and high-density lipoprotein-cholesterol (HDLc), as well as atherogenic indices (TC/HDLc and LDLc/HDLc), and also to analyse the diet over 11 weeks of training in female professional volleyball players. The lipid profile of 22 female professional volleyball players was analysed on Day T0 (pre-preseason) and Day T11 (after 11 weeks of training). The consumption of fats by the players was estimated using a food frequency questionnaire, confirmed by seven days of full dietary records. By the end of the study, the LDLc levels and both atherogenic indices of the players had decreased (p professional volleyball players during the first 11 weeks of training in the season was heart healthy, because their lipid profile improved, despite an inadequate intake of fats.

  7. Psycho-physical perfection of economic specialties’ girl students under influence of sport-oriented technology, based on prevalence of volleyball practicing

    Directory of Open Access Journals (Sweden)

    I.O. Salatenko

    2015-12-01

    Full Text Available Purpose: to work out content of sport-oriented technology of physical education, based on prevalence of volleyball practicing. Material: in the research two experimental (n=25, n=25 and one control (n=25 groups of girl students participated. The content of sport-oriented technology, based on prevalence of volleyball practicing included additionally elements of fitness. студенток. Quickness of mental processes and efficiency of mind operations were assessed with the help of special cards, on which 9 dials with pointers were depicted. The sense of test was: addition of dials’ readings in mind; simultaneous calculation of value of scale one division; keeping in memory the previous sum of readings. This task was to be fulfilled for 6 minutes. Results: it was found that quickness of mental processes and mind operations as well as operative memory were at level below average. The most expressed positive factor was registered in group in which circle sport trainings were conducted. It was also found that over-fatigue at the end of academic year influences on testing indicators. Conclusions: the offered by us sport-oriented technology, based on prevalence of volleyball practicing can be recommended as effective mean of economic specialties girl students’ psycho-physical qualities’ strengthening.

  8. Strategy as simple rules.

    Science.gov (United States)

    Eisenhardt, K M; Sull, D N

    2001-01-01

    The success of Yahoo!, eBay, Enron, and other companies that have become adept at morphing to meet the demands of changing markets can't be explained using traditional thinking about competitive strategy. These companies have succeeded by pursuing constantly evolving strategies in market spaces that were considered unattractive according to traditional measures. In this article--the third in an HBR series by Kathleen Eisenhardt and Donald Sull on strategy in the new economy--the authors ask, what are the sources of competitive advantage in high-velocity markets? The secret, they say, is strategy as simple rules. The companies know that the greatest opportunities for competitive advantage lie in market confusion, but they recognize the need for a few crucial strategic processes and a few simple rules. In traditional strategy, advantage comes from exploiting resources or stable market positions. In strategy as simple rules, advantage comes from successfully seizing fleeting opportunities. Key strategic processes, such as product innovation, partnering, or spinout creation, place the company where the flow of opportunities is greatest. Simple rules then provide the guidelines within which managers can pursue such opportunities. Simple rules, which grow out of experience, fall into five broad categories: how- to rules, boundary conditions, priority rules, timing rules, and exit rules. Companies with simple-rules strategies must follow the rules religiously and avoid the temptation to change them too frequently. A consistent strategy helps managers sort through opportunities and gain short-term advantage by exploiting the attractive ones. In stable markets, managers rely on complicated strategies built on detailed predictions of the future. But when business is complicated, strategy should be simple.

  9. Rules, culture, and fitness.

    Science.gov (United States)

    Baum, W M

    1995-01-01

    Behavior analysis risks intellectual isolation unless it integrates its explanations with evolutionary theory. Rule-governed behavior is an example of a topic that requires an evolutionary perspective for a full understanding. A rule may be defined as a verbal discriminative stimulus produced by the behavior of a speaker under the stimulus control of a long-term contingency between the behavior and fitness. As a discriminative stimulus, the rule strengthens listener behavior that is reinforced in the short run by socially mediated contingencies, but which also enters into the long-term contingency that enhances the listener's fitness. The long-term contingency constitutes the global context for the speaker's giving the rule. When a rule is said to be "internalized," the listener's behavior has switched from short- to long-term control. The fitness-enhancing consequences of long-term contingencies are health, resources, relationships, or reproduction. This view ties rules both to evolutionary theory and to culture. Stating a rule is a cultural practice. The practice strengthens, with short-term reinforcement, behavior that usually enhances fitness in the long run. The practice evolves because of its effect on fitness. The standard definition of a rule as a verbal statement that points to a contingency fails to distinguish between a rule and a bargain ("If you'll do X, then I'll do Y"), which signifies only a single short-term contingency that provides mutual reinforcement for speaker and listener. In contrast, the giving and following of a rule ("Dress warmly; it's cold outside") can be understood only by reference also to a contingency providing long-term enhancement of the listener's fitness or the fitness of the listener's genes. Such a perspective may change the way both behavior analysts and evolutionary biologists think about rule-governed behavior.

  10. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel

    2013-01-01

    A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series of undra...

  11. Radiation safety in Australia's mineral sands industry

    International Nuclear Information System (INIS)

    Hughes, W.

    1989-06-01

    This brochure is part of a training package aiming to explain in simple terms what radiation is, how it affects people's lives and how, in the specific case of the mineral sand industry, the risk of ill-effects from low-level radioactivity could be effectively guarded against by simple and easily followed safety precautions. ills

  12. Geomechanical properties of lime stabilized clayey sands

    International Nuclear Information System (INIS)

    Arabani, M.; Karami, M. Veis

    2007-01-01

    Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

  13. Market opportunities and challenges for oil sands

    International Nuclear Information System (INIS)

    Wise, T.H.

    2004-01-01

    The use of Alberta bitumen as a clean fuel depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production from the Western Canada Sedimentary Basin. The challenges facing the oils sands processing industry include: crude oil prices which affect the producer's market; market expansion options; diluent availability/cost; supply cost competitiveness; and, regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. It was noted that Alberta must retain or increase its share of the Midwest market. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. New pipeline capacity is needed to reach more distant markets such as Southern Midwest, Washington, and California. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. 13 figs

  14. Growing markets to sustain oil sands development

    International Nuclear Information System (INIS)

    Wise, T.H.

    2003-01-01

    The utilization of Alberta bitumen for the clean fuels market depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production in Western Canada. Several issues pose a challenge to the oil sands processing industry. The producers' market is affected by crude oil prices, market expansion options, diluent availability/cost, supply cost competitiveness, and regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. A brief review of markets for Canadian crude oil, including synthetic crude, was provided. The share of the Midwest market by Alberta must be retained and increased. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. To reach more distant markets such as Southern Midwest, Washington, and California, new pipeline capacity would be required. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. tabs., figs

  15. Microbial Characterization of Qatari Barchan Sand Dunes.

    Directory of Open Access Journals (Sweden)

    Sara Abdul Majid

    Full Text Available This study represents the first characterization of sand microbiota in migrating barchan sand dunes. Bacterial communities were studied through direct counts and cultivation, as well as 16S rRNA gene and metagenomic sequence analysis to gain an understanding of microbial abundance, diversity, and potential metabolic capabilities. Direct on-grain cell counts gave an average of 5.3 ± 0.4 x 105 cells g-1 of sand. Cultured isolates (N = 64 selected for 16S rRNA gene sequencing belonged to the phyla Actinobacteria (58%, Firmicutes (27% and Proteobacteria (15%. Deep-sequencing of 16S rRNA gene amplicons from 18 dunes demonstrated a high relative abundance of Proteobacteria, particularly enteric bacteria, and a dune-specific-pattern of bacterial community composition that correlated with dune size. Shotgun metagenome sequences of two representative dunes were analyzed and found to have similar relative bacterial abundance, though the relative abundances of eukaryotic, viral and enterobacterial sequences were greater in sand from the dune closer to a camel-pen. Functional analysis revealed patterns similar to those observed in desert soils; however, the increased relative abundance of genes encoding sporulation and dormancy are consistent with the dune microbiome being well-adapted to the exceptionally hyper-arid Qatari desert.

  16. Afyon-Sandıklı

    Indian Academy of Sciences (India)

    δ18O and δD isotope ratios of the Sandıklı waters plot along the continental meteoric water line ... and district heating. Several studies on geology, hydrogeology along ..... precipitation; In: Handbook of Environmental Isotope. Geochemistry ...

  17. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

    In the secondary Italian school the Earth science learning begins at first year, in synergy with other natural science subjects such as Astronomy, Chemistry and Biology. Italian teachers have to focus on the landscape geomorphological aspects and often Earth processes are difficult to display since they are related to certain phenomena happened during the past and often far from the involved country. In order to better understand the environment surrounding us, very simple and poor materials, like sands, allow the teachers to create attractive lab experiences. According to the IBSE (Inquiry Based Science Education) approach, a learning unit has been implemented starting from a walking along the light carbonate beaches of the Adriatic sea: a smart look to the sands ("engage step"), stroke the students fantasy pushing them to explore some strange black grains on the sands. Dirty sands? Or rock landscape, soil degradation and Ofanto river and coastal processes (erosion, transportation and deposition)? This was the teaching challenge. Due to the youngest age, a third level, guided inquiry, was adopted so the teacher is the "guide of inquiry" encouraging the students using the research question ("Why is the sand dark?", "Do all sands look the same?", "Where does it come from?") and driving the students around their investigation plans ("How can I measure grain size?"). A procedure to answer the above questions and validate the results and explanations has been implemented to allow the students to be proactive in their study. During the learning activities will be the students to ask for field trip to elaborate their new knowledge, verify and visualize the speculated processes. The teaching skills allow to address several geosciences domains such as mineralogy, petrology, regional geology and geodynamics as well as other scientific disciplines such as mathematics (more specifically statistics), forensic science and even life sciences (the presence of bioclasts might

  18. The provenance of Taklamakan desert sand

    Science.gov (United States)

    Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

    2016-03-01

    Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

  19. High temperature thermal energy storage in moving sand

    Science.gov (United States)

    Turner, R. H.; Awaya, H. I.

    1978-01-01

    Several high-temperature (to 500 C) heat-storage systems using sand as the storage medium are described. The advantages of sand as a storage medium include low cost for sand, widespread availability, non-toxicity, non-degradation characteristics, easy containment, and safety. The systems considered include: stationary sand with closely spaced tubes throughout the volume, the use of a fluidized bed, use of conveyor belt transporter, and the use of a blower rapid transport system. For a stationary sand bed, very close spacing of heat transfer tubes throughout the volume is required, manifesting as high power related system cost. The suggestion of moving sand past or around pipes is intended to reduce the power related costs at the penalty of added system complexity. Preliminary system cost estimates are offered. These rough calculations indicate that mobile sand heat storage systems cost less than the stationary sand approach.

  20. Characteristics of SCC with Fly Ash and Manufactured Sand

    Science.gov (United States)

    Praveen Kumar, K.; Radhakrishna

    2016-09-01

    Self compacting concrete (SCC) of M40 grade was designed. The binder in SCC consists of OPC and fly ash in the ratio of 65:35. River sand was replaced by manufactured sand (M-sand) at replacement levels of 20,40,60,80 and 100%. An attempt was made to evaluate the workability and strength characteristics of self compacting concrete with river sand and manufactured sand as fine aggregates. For each replacement level, constant workability was maintained by varying the dosage of superplasticizer. T50 flow time, V Funnel time, V-funnel T5 time as well as compressive, split tensile and flexural strength of SCC were found at each replacement level of M-sand. They were compared to SCC with river sand. Results indicate favourable use of M-sand in preparation of Self Compacting Concrete.