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834 Uppsatser om Signal Strength - Sida 9 av 56
Utdragshållfasthet hos limmade och olimmade gängstänger i limträ
This essay examines pull-out strength of threaded rods fixed into glulam timber. The technology is intended to be used in hidden joints between glulam components. The work began with a study of literature focusing on current research within the topic, mainly to create a base of knowledge before the testing was initiated. Studies of scientific articles reveals a lack of research within this area, which makes it difficult to develop standards and calculation models for these joints. The drill holes in the tests have a diameter of 7 mm.
Aktiv bullerdämpning i ventilationssystem
Active headsets have been on the market for years and now it is time for
something else to enter the stage. The technology of active noise reduction can
for exmple also be used in ventilation systems for reducing ventilation noise.
An active control system principally consists of four important components,
namely the downstream error microphone, the upstream detection or reference
microphone, the digital signal processor (DSP) and a loudspeaker.
The upstream reference microphone listen to the primary ventilation noise and
sends it to the DSP which makes a phase shift to the signal and sends it to the
loudspeaker. The loudspeaker sends out the opposite waveform of the incoming
one and reduce the primary ventilation noise.
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.
Implementering av Constant Fraction Detection vid avståndsmätning
This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.
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.
Analys och dimensionering av robusta kilspårsförband
This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.
Undersökning av energiförbrukning och konceptutveckling av mer energisnåla frukostmaskiner
This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.
Signal- och bildbehandling på moderna grafikprocessorer
En modern grafikprocessor är oerhört kraftfull och har en prestanda som potentiellt sett är många gånger högre än för en modern mikroprocessor. I takt med att grafikprocessorn blivit alltmer programmerbar har det blivit möjligt att använda den för beräkningstunga tillämpningar utanför dess normala användningsområde. Inom det här arbetet utreds vilka möjligheter och begränsningar som uppstår vid användandet av grafikprocessorer för generell programmering. Arbetet inriktas främst mot signal- och bildbehandlingstillämpningar men mycket av principerna är tillämpliga även inom andra områden.Ett ramverk för bildbehandling implementeras och några algoritmer inom bildanalys realiseras och utvärderas, bland annat stereoseende och beräkning av optiskt flöde. Resultaten visar på att vissa tillämpningar kan uppvisa en avsevärd prestandaökning i en grafikprocessor jämfört med i en mikroprocessor men att andra tillämpningar kan vara ineffektiva eller mycket svåra att implementera..
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 %).