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518 Uppsatser om Tensile strength - Sida 5 av 35

Koffeinets inverkan på prestationsförmågan vid styrketräning ? En systematisk översiktsartikel

AbstractTitle: The effect of caffeine on performance during resistance training ?A systematic overviewAuthor: Amanda Jonsson and Erica BenderSupervisor: Mette AxelsenExaminer: Anna WinkvistProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: 2015-03-31Background: Products with high content of caffeine has in recent years become popular for optimizing physical performance. Caffeine affects mechanisms in our body which can be beneficial to perform better during exercise, but the theories have not yet been systematically reviewed.Objective: The purpose of this review article, is to examine the acute effect of caffeine intake before strength training on athletic performance with the outcome muscle endurance.Search strategy: A systematic literature search in databases PubMed, Scopus and Cochrane using keywords: ?Caffeine?, ?strength?, ?muscle?, "resistance training", "muscle strength", "strength training", "athletic performance", ?repetitions to failure?, ?muscular endurance? and ?endurance training?.Selection criteria: Healthy subjects, 16-50 years old, with experience in strength training. Studies with a caffeine intake > 5 mg/kg body weight, which participants performed dynamic strength exercises on a weight > 60% of their 1 RM.

Vidhäftning mellan prefabelement och pågjutningsbetong : Undersökning hur skrovligheten påverkar vidhäftningskapaciteten vid skjuvning

Self-compacting concrete has soon been around for a decade. Recently the prefabrication industry has started to use this fairly new concrete type in larger scales, mainly because of its distinctive properties.  There are still certain areas that need to be thoroughly examined, such as bond capacity. There have been very few studies regarding shear capacity due to the fact that the procedure is complicated.This report will highlight a method to examine the shear capacity of different surfaces that have been prewetted as well as non-prewetted surfaces. The surface areas follow BBK 04?s and Eurocode 2?s demand for surface roughness.  A smooth surface will be completed in order to confirm if the different shapes influence the bond strength by shear stress or not.                       The purpose of this essay is to measure the bond strength within the shear capacity as well as examine the impact it has on surface roughness and treatment for shear bond.The method used to identify the shear capacity is called L-shaped Push-Off Test.

Hur påverkas muskelaktiviteten vid styrketräning med en tjock stång i jämförelse med en standardolympisk stång? : En EMG- studie

Many everyday tasks and also many sports require good grip and forearm strength. Everything from carrying boxes and lifting a child to grab the arms and legs in various martial arts, or holding a tennis racket involving the hand and forearm muscles in various ways. It is therefore important to train these muscles to prevent injuries and congestion and to perform well in sport. A well known way to train functional strength in the hand and forearm muscles is weight training with thick handles. The purpose of this study was to investigate the differences in muscle activity in the upper arm and forearm muscles as well as the deltoids between two bars of different diameter (28mm and 57mm) in two different weight training exercises using electromyography (EMG).

Betong - Förvånansvärt lättflytande!

Concrete is a very common construction material. It´s characteristics are strength, durability and formablility. Superplasticizer is a common admixture, which changes the properties of concrete. Today (spring 2007) there are no certian mathematical methods to calculate the required percentage of this admixture needed to give the necessary set slump flow in the overall concrete recipe. Concrete batching companies must therefor experiment with different amount of superplasticizer in order to meet the specified slump and strength. The purpose og this report is to investigate if any mathematical relation can be established between the amount of superplasticizer used and the slump flow achieved. After carrying out some practical experiments using four different superplasticizers a direct relationship can be establish between the percentage of admixture used and the slump/flowability achieved. Unfortunatly at present due to the numerous variables, the calculation of mathematical formula can not be achieved..

Miljövärdering av resurssnål betong med införande i BIM

This thesis aims to illustrate how environmental impact can be reduced, through the use of lean concrete. It also illustrates how environmental data can be applied to a house through implementation with BIM. In this study a unique concrete structure developed by Swedish Cement and Concrete Research Institute is assessed for environmental impact, by calculating the carbon dioxide equivalents using LCA methodology. The construction is a sandwich element where the concrete is made ??up of three layers.

Träning och manuell behandling för att minska impingementliknande symptom i skuldran hos idrottare? : En systematisk litteraturstudie

AimThe purpose of this study is to investigate whether there is scientific evidence that exercise and/or manual therapy can improve function, in terms of increased mobility and strength on shoulder impingement-like symptoms among athletes. Another aim is to investigate whether these interventions can reduce shoulder pain.MethodA systematic review was conducted in the databases PubMed, CINAHL, PEDro and Amed. A total of thirteen articles were selected for further review and compilation. They were then graded for level of evidence according to the PEDro scale and the Swedish Council on Technology Assessment (SBU).ResultsThe systematic review shows that there is strong scientific evidence that acupuncture and heat can reduce pain in athletes diagnosed with supraspinatus-tendiopathy. There is limited scientific evidence that exercise increases strength, limited scientific evidence that stretching increases mobility and insufficient scientific evidence that a combination of treatments, with both exercise and stretching, reduces pain and increases function in overhead athletes.ConclusionsExercise and manual therapy can reduce pain and/or improve function in terms of increased mobility and strength in athletes with shoulder impingement-like symptoms.

Styrketillväxt med hjälp av vibrationsplatta

Abstract 1.The purpose of this study was to investigate the effects whole body vibrations on maximal strength, power output and neuromuscular activity in m. pectoralis major during bench press.Participants consisted of 35 male and 9 female military high school students (m=23, 1 years). On the basis of initial maximal performances in bench press the participants was divided into two experiments groups and one control group. Intervention groups performed a specifically designed push up program on a vibrating plate respectively a step board during 12 weeks Initial load at 60 % of 1 RM showed an average of 46, 5 kg. All groups showed an average increase of 13 kg for each person after 12 weeks.

Yoga och isometrisk uthållighet i bål : Yogautövningens påverkan på den fysiska och mentala allmänhälsan

Abstract The core is the center of gravity in our body. Injuries and overload in the joints, is the most common reason for not be able to work in Sweden today. A god strength capacity in the core is important for secure and effective movements, as well for active athletes, as for non athletes. The increased number of employees, who report in sick today, has been correlated with psychological bad health. New methods to deal with mental and physical health problems among people can indicate to the fact that Yoga in the western world has increased its members, due its spiritual and physical recognition in favor of well being.

Ljusspridningsvariationer i finpapperstillverkning

The purpose of this Master's thesis is to find possible explanations of variation in light scattering in a fine paper. Samples were collected from each second tambour during a time period of two weeks from a paper machine at MoDo Paper, Husum. Two data sets, consisting of 20 and 95 observations, were selected for extensive analysises of tensile and structual properties. The data was evaluated with multivariate data techniques using the programs Simca and Extract. The results of PCA- and PLS- analysises pointed out 3 of 52 variables as important for the variations in light scattering.

Effekterna av praktisk ocklusionsträning periodiserat med ett traditionellt styrketräningsprogram på anaerob prestation

Background: Practical blood flow restriction (pBFR) combined with resistance training has been proven to facilitate muscle strength despite training at low intensity. However, research investigating the effects of long-term pBFR-training and its periodization with strength training (ST) at a higher intensity is lacking, as well as the effects of occlusion training on blood lactate levels (BLL) over time.Purpose: To compare the effects of 2 weeks of pBFR training followed by 2 weeks of ST (BFR-ST) with 2 weeks of ST followed by 2 weeks of pBFR training (ST-BFR) on anaerobic performace and BLL.Method: 5 adults (age 23 ± 2 years) with a minimum of 1 year of ST experience were recruited and randomized into BFR-ST (n=2) or ST-BFR (n=3). Anaerobic performance was measured using a 30-s Wingate-test and BLL samples were collected <1 and 5 minutes post-Wingate. Data and samples were collected before the intervention and after the 2 protocols.Results: No differences were seen between groups in anaerobic output or BLL after 4 weeks of training (p>0,1 for all values). A decrease in time to peak power (tPP) were seen in both groups with an advantage for BFR-ST (-37 ± 8 %) over ST-BFR (-27 ± 22 %).

Line–extensions; A longitudinal study concerning effects on brand equity

Thesis purpose The study aims to examine the effects vertical and horizontal line extensions might have on the total parent brand equity in terms of strength and its baseline product regarding of market share, loyalty and penetration under an elapsed period of time. The study aims to investigate a number of actual conducted line extensions effect on the above mentioned aspects of Kellers (1993) definition of brand strength as a part of the total brand equity. Methodology The effect of a number of line extensions of the parent brands and the baseline products is being examined in terms of market share, loyalty rate, cannibalization and market penetration. The thesis is focused on the correlations between these different parameters during a certain elapsed time ratio in order to test our theoretically routed hypothesizes in a deductive manner. Occasional correlations are derived from an indexation of data collected from the Gfk database. Theoretical perspective The study is derived from Kapferers (2004) definition of brand equity, where he is dividing the concept into three parts. This study is focused on Brand strength in particular, which is one of the parameters in the above-mentioned theory.

Utdragshållfasthet av inlimmade skruvar i limträ

In this thesis tests has been performed on the pull strength of screws glued into glulam beams.The experiment is based on the already approved method whereby the diameter of the drilled holes is the same as the screw outer diameter of 1 mm or bigger. The screws strength class shall not be less than 4.6 (EN ISO 898-1:1999, 1999).The difference in the experiments that were performed where that the drilled diameter were 1 mm smaller than the outer diameter of the screw so that the screw thread was worked into the wood.In the tests the gluing where made on M8 glulam beams. The screws where drilled at and angel of 90°tangental to the fiber direction with a diameter of 7 mm. The gluing of the screws where made in three different depths and where later exposed to pulling forces. The results showed both pulling breaks and screw breaks when they reached their maximum capacity.

Line?extensions; A longitudinal study concerning effects on brand equity

Thesis purposeThe study aims to examine the effects vertical and horizontal line extensions might have on the total parent brand equity in terms of strength and its baseline product regarding of market share, loyalty and penetration under an elapsed period of time. The study aims to investigate a number of actual conducted line extensions effect on the above mentioned aspects of Kellers (1993) definition of brand strength as a part of the total brand equity. MethodologyThe effect of a number of line extensions of the parent brands and the baseline products is being examined in terms of market share, loyalty rate, cannibalization and market penetration. The thesis is focused on the correlations between these different parameters during a certain elapsed time ratio in order to test our theoretically routed hypothesizes in a deductive manner. Occasional correlations are derived from an indexation of data collected from the Gfk database.

Development of concrete compressive strength: a study of Swedish bridges constructed during the 20th century

Tryckhållfasthetsutveckling hos broar. En studie av svenska broar byggda under 1900-talet.

Brunstvisningsförmåga hos SRB- och Holsteinkvigor

Oestrus in dairy cattle has changed over the last decades, the duration has decreased and the intensity of oestrus has declined. A possible explanation can be their high and increasing milk production. Heifers ability to show oestrus is probably not affected to the same extent. The aim of this study was to estimate and compare oestrus duration and strength in heifers of the Swedish Red and Holstein breeds. Standing oestrus has been the primary oestrus sign during many years.

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