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Análise da existência de máxima fase estável de lactato nos exercícios resistidos leg press 45º e supino reto / Analysis of the existance of a maximal lactate steady state on resistance exercises leg press 45° and bench pressMagosso, Rodrigo Ferro 26 July 2010 (has links)
O objetivo deste estudo foi verificar se existe máxima fase estável de lactato (MFEL) nos exercícios LP e SR e analisar o comportamento de variáveis ventilatórias ventilação (Ve) e consumo de oxigênio (VO2), bem como lactacidemia, freqüência cardíaca (FC) e percepção subjetiva de esforço (PSE) na intensidade da MFEL e comparar as respostas entre os exercícios. Foram avaliados 12 homens jovens (20-33 anos) saudáveis e com experiência mínima de 6 meses em treinamento resistido, que passaram por teste de 1 repetição máxima (1RM), teste crescente para determinação do limiar anaeróbio (AT) e mais três sessões para a determinação da MFEL. Todas as sessões foram realizadas no mesmo horário do dia, separadas por 48 a 72 horas de intervalo. O valor de 1RM no LP foi de 298,0 ± 36,6 kg enquanto que no SR foi 93,7 ± 21,8 kg. A intensidade máxima atingida no teste crescente no LP foi 70,00 ± 12,25% de 1RM e no SR 50,00 ± 8,16% de 1RM, sendo esta diferença estatisticamente significativa (p0,05). A lactacidemia final também foi significativamente maior (p0,05) no LP comparada ao SR (8,36 ± 2,34 vs. 5,43 ± 1,12 mmol/L, respectivamente). O AT, expresso em percentual de 1RM, no LP foi de 27,9 ± 3,7% e no SR de 24,1 ± 4,4% de 1RM, porém esta diferença não foi estatisticamente significante. A lactacidemia no momento do teste crescente em que o AT era atingido também não apresentou diferença significativa, sendo 2,29 ± 0,58 mmol/L no LP e 2,52 ± 0,65 no SR. A intensidade da MFEL, no LP foi de 29,17 ± 7,02% de 1RM, enquanto que no SR a intensidade da MFEL foi de 21,67 ± 4,44% de 1RM, sendo esta diferença estatisticamente significativa (p0,05). No LP não houve diferença significativa entre as intensidades do AT e da MFEL (27,9 ± 3,7% e 29,2 ± 7,0% de 1RM, respectivamente). No SR intensidade do AT foi significativamente maior (p0,05) que a intensidade da MFEL (24,1 ± 3,4% e 21,7 ± 4,4% de 1RM, respectivamente). Durante a realização de exercício na MFEL, a ocorreu aumento de Ve, VO2, FC e PSE seguidos de estabilização, sem diferenças entre os exercícios. Estes resultados demonstram que é possível verificar MFEL nos exercícios LP e SR, e que no LP a intensidade é maior. As diferenças encontradas no teste crescente e na intensidade da MFEL são provavelmente causadas pelas características dos exercícios. / The purpose of the study was to verify if there is a maximal lactate steady state (MLSS) for the Leg Press (LP) and Bench Press (BP) exercises and to analyse ventilatory responses ventilation (Ve) and oxygen uptake (VO2), heart rate (HR), blood lactate concentration (BLC) and ratings of perceived exertion (RPE) to those exercises performed on MLSS intensity and to compare those responses for the exercises. 12 young healthy men with a minimal experience of 6 months of resistance training volunteered for the study. Volunteers underwent a 1 repetition maximum test (1RM), na incremental test to determine anaerobic threshold (AT) and three more sessions to determine MLSS. Session were performed on the same time of Day and separeted by a 48-72h interval. 1RM values for LP and BP were 298,0 ± 36,6kg and 93,7 ± 21,8 kg, respectively. The maximal intensity in the incremental test was 70 ± 12,25% of 1RM for LP and 50,00 ± 8,16% of 1RM for BP, which was a significant difference (p0,05). Post-test blood lactate concentration (BLS) was also significantly higher for LP (8,36 ± 2,34 vs. 5,43 ± 1,12 mmol/L, respectively) (p0,05). AT intensity and was not significantly different for LP and BP (27,9 ± 3,7% vs. 24,1 ± 3,6, respectively). BLC on AT was not significantly different for LP (2,29 ± 0,58 mmol/L) and BP (2,52 ± 0,65). MLSS intensity on LP (29,17 ± 7,02% of 1RM) was significantly higher (p0,05) compared to MFEL on BP (21,67 ± 4,44% of 1RM). When compared to AT, MLSS intensity for LP was not significantly different, but for BP it was significantly lower. During exercise on MLSS, oxygen uptake and ventilation, HR and RPE rose significantly compares to rest and then stabilized. There were no differences between exercises. These results show that it is possible to identify a MLSS on the LP and BP exercises, and that for LP this intensity is higher. The differences found between exercises can be atributted to the intrinsic caractheristics of each exercise.
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Auditory Steady State Responses Recorded in Multitalker BabbleLeigh-Paffenroth, Elizabeth D., Murnane, Owen D. 01 February 2011 (has links)
Objective: The primary purpose of this investigation was to determine the effect of multitalker babble on ASSRs in adult subjects with normal hearing (NH) and sensorineural hearing loss (HI). The secondary purpose was to investigate the relationships among ASSRs, word recognition in quiet, and word recognition in babble. Design: ASSRs were elicited by a complex mixed-modulation tonal stimulus (carrier frequencies of 500, 1500, 2500, and 4000 Hz; modulation rate of 40 or 90 Hz) presented in quiet and in babble. The level of each carrier frequency was adjusted to match the level of the multitalker babble spectrum, which was based on the long term speech spectrum average. Word recognition in noise (WIN) performance was measured and correlated to ASSR amplitude and ASSR detection rate. Study Sample: Nineteen normal-hearing adults and nineteen adults with sensorineural hearing loss were recruited. Results and Conclusions: The presence of babble significantly reduced the ASSR detection rate and ASSR amplitude for NH subjects, but had minimal effect on ASSRs for HI subjects. In addition, babble enhanced ASSR amplitude at high stimulus levels. ASSR detection rate and ASSR amplitude recorded in quiet and babble were significantly correlated with word recognition performance for NH and HI subjects.
Sumario
Objetivo: El objetivo fundamental de esta investigación fue determinar el efecto de balbuceo de hablantes múltiples en los ASSR de adultos jóvenes con audición normal (NH) y con pérdidas auditivas sensorineurales (HI). El objetivo secundario fue investigar las relaciones entre los ASSR, el reconocimiento de palabras en silencio y el reconocimiento de palabras con en medio de balbuceo. Diseño: Los ASSR fueron evocados por estímulo tonal de modulación mezclada compleja (frecuencias portadoras de 500, 1500, 2500 y 4000 Hz; tasa de modulación de 40 o 90 Hz) presentadas en silencio y con el balbuceo. Se ajustó el nivel de cada frecuencia portadora para emparejar el nivel del espectro del balbuceo de hablantes múltiples, el cual se basó en el promedio del espectro a largo plazo. Se midió el rendimiento para el reconocimiento de palabras en ruido (WIN) y se correlacionó con la amplitud de los ASSR y con la tasa de detección de los ASSR. Muestra Del Estudio: Se reclutaron diez y nueve adultos normoyentes y diez y nueve adultos con pérdida auditiva sensorineural. Resultados Y Conclusiones: La presencia del balbuceo reduce significativamente la tasa de detección de los ASSR y la amplitud de los ASSR en sujetos NH, pero tiene efectos mínimos en los ASSR de sujetos HI. Además, el balbuceo aumenta la amplitud de los ASSR con estímulos de niveles altos. La tasa de detección de los ASSR y la amplitud de los ASSR registrada en silencio y con balbuceo, fueron significativamente correlacionadas con el rendimiento para reconocer palabras en sujetos NH y HI.
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[en] STATIC AND DYNAMIC SIMULATION FOR GENERATOR VOLTAGE CONTROL / [pt] SIMULAÇÃO ESTÁTICA E DINÂMICA DO CONTROLE DE TENSÃO POR GERADORESLUIS FERNANDO FERREIRA 09 January 2007 (has links)
[pt] O problema tratado nesta dissertação é a relação oposta
entre a tensão de
excitação de geradores e compensadores síncronos e a tensão
controlada,
quando o sistema de transmissão da área encontra-se muito
carregado. Neste
caso, a capacidade nominal de um gerador / compensador não
seria útil para
manter a tensão controlada. Devido à relação oposta, uma
maior excitação da
máquina iria abaixar a tensão controlada. O controle
automático iria continuar
agindo, abaixando ainda mais a tensão. Este mecanismo pode
levar o sistema
ao colapso e foi verificado em ponto de operação real do
sistema brasileiro. Esse
fenômeno ocorre quando a injeção de potência na rede de
transmissão ou
distribuição é elevada. Com o advento da geração
distribuída, co-geração e
produtores independentes, usualmente conectados à rede
existente em níveis de
tensão mais baixas, têm-se observado ocorrências do
fenômeno. O objetivo do
trabalho é então entender melhor as situações operativas
reais que levam à
ocorrência do fenômeno, principalmente quando existem
vários equipamentos de
controle de tensão ao redor do gerador em análise. A
abordagem do problema
baseou-se na verificação do comportamento do gerador /
compensador como
dispositivo de controle de tensão, no domínio do tempo e em
regime
permanente. Avaliaram-se as ações de controle do mesmo a
partir de sete tipos
de análise distintas para pontos de operação na região
normal e anormal da
curva SV. A real existência do fenômeno foi comprovada
através de algumas
destas análises. Porém, conclui-se que nem todas as formas
de análise no
domínio do tempo fazem uma avaliação completa do fenômeno.
Dentre essas,
estão a análise dinâmica agregada e a análise dinâmica
agregada sob influência
dos equipamentos de controle de tensão, que para pontos de
operação na
região anormal da curva SV não responderam em concordância
com os outros
tipos de análise. / [en] The problem addressed in this research is the opposite
relationship
between the , synchronous generator / compensator
excitation voltage and the
controlled voltage when nearby network is heavily loaded.
In this situation, the
nominal capacity of a generator / compensator would not
keep the voltage
controlled. Due to the opposite relationship, the higher
the excitation voltage the
lower is the controlled voltage. So, the automatic control
would continue acting
lowering the voltage. This mechanism, verified in a real
operational point of the
Brazilian Electric System, can lead the system to collapse.
This phenomenon
occurs when the power injection into the network is high.
It is prone to occur in
the new scenario of distributed generation connected to
already existing low
voltage networks. The objective of this work is to
understand the actual operative
situations that lead to the occurrence of the phenomenon,
mainly when there are
several voltage control devices nearby the generator. The
analysis of the problem
was based on the verification of the generator behaviour as
a voltage control
device, in time domain simulation and in steady state. The
control actions were
evaluated from seven different ways for operating points in
the normal and the
abnormal region of the SV curve. The actual existence of
the phenomenon was
proven through some of these analyses. However, some of the
time domain
simulations did not evaluated the phenomenon completely.
Among them, the
aggregated dynamic analysis and the aggregated dynamic
analysis under
influence of other voltage control devices have not got the
expected
responses for the abnormal region of the SV curve, in
comparison with other
analysis.
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An artificial compressibility analogy approach for compressible ideal MHD: Application to space weather simulationYALIM, Mehmet Sarp 05 December 2008 (has links)
Ideal magnetohydrodynamics (MHD) simulations are known to have problems in satisfying the solenoidal constraint (i.e. the divergence of magnetic field should be equal to zero, $
ablacdotvec{B} = 0$). The simulations become unstable unless specific measures have been taken.
In this thesis, a solenoidal constraint satisfying technique that allows discrete satisfaction of the solenoidal constraint up to the machine accuracy is presented and validated with a variety of test cases. Due to its inspiration from Chorin's artificial compressibility method developed for incompressible CFD applications, the technique was named as extit{artificial compressibility analogy (ACA)} approach.
It is demonstrated that ACA is a purely hyperbolic, stable and consistent technique, which is moreover easy to implement. Unlike some other techniques, it does not pose any problems of the sort that $
ablacdotvec{B}$ errors accumulate in the vicinity of the stagnant regions of flow. With these crucial properties, ACA is thought to be a remedy to the drawbacks of the most commonly used solenoidal constraint satisfying techniques in the literature namely: Incorrect shock capturing and poor performance of the convective stabilization mechanism in regions of stagnant flow for Powell's source term method; exceedingly complex implementation for constrained transport technique due to the staggered grid representation; computationally expensive nature due to the necessity of a Poisson solver combined with hyperbolic/elliptic numerical methods for classical projection schemes.
In the first chapter of the thesis, general background knowledge is given about plasmas, MHD and its history, a certain class of upwind finite volume methods, namely Riemann solvers, and their applications in MHD, the definition, constituents, formation mechanisms and effects of space weather and some of the space missions that are and will be performed in its prediction.
Secondly, detailed analysis of the compressible ideal MHD equations is given in the form of the derivation of the equations, their dimensionless numbers which will be of use to specify the flows in the following chapters, and finally, the presentation of the MHD waves and discontinuities, which indicates the complexity of the system of ideal MHD equations and therefore their further numerical analysis.
The next discussion is about the main subject of the thesis, namely the solenoidal constraint satisfying techniques. First of all, the definition and significance of the solenoidal constraint is given. Afterwards, the most common solenoidal constraint satisfying techniques in the literature are reviewed along with their abovementioned drawbacks. Moreover, particular emphasis is given to the Powell's source term approach which was also implemented in the upwind finite volume MHD solver developed. In addition, the hyperbolic divergence cleaning technique is presented in detail together with the resemblance and differences between it and ACA. Some other solenoidal constraint satisfying techniques are briefly mentioned at this stage. After these, ACA is presented in the following way: The point of inspiration, which is the analogy made with Chorin's artificial compressibility method developed for incompressible CFD, the introduction of the modified system of ideal MHD equations due to ACA, the derivation of the wave equation governing the propagation of $
ablacdotvec{B}$ errors and the analytical consistency proof.
Having finished the core discussion of the thesis, the solver developed and its constituents are given in the fourth chapter. Furthermore, a brief overview of the platform into which this solver was implemented, namely COOLFluiD, is also given at this point.
Afterwards, a thorough numerical verification of the ACA approach has been made on an increasingly complex suite of test cases. The results obtained with ACA and Powell's source term implementations are given in order to numerically analyse and verify ACA and compare the two methods and validate them with the results from literature.
The sixth chapter is devoted to further validation of ACA performed with a variety of more advanced space weather-related simulations. In this chapter, also the $vec{B}_{ extrm{0}} + vec{B}_{ extrm{1}}$ splitting technique used to treat planetary magnetosphere is presented along with its application to ACA and Powell's source term approaches. This technique is utilized in obtaining the solar wind/Earth's magnetosphere interaction results and is based on suppressing the direct inclusion of the Earth's magnetic field, which is a dipole field, in the solution variables. In this way, problems are avoided with the energy equation that could arise from the drastic change of the ratio of the dipole field and the variable field computed by the solver (i.e. $frac{lvertvec{B}_{ extrm{0}}lvert}{lvertvec{B}_{ extrm{1}}lvert}$) in the computational domain.
Finally, conclusions and future perspectives related to the material presented in the thesis are put forward.
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Regional Growth in Sweden : A Study of Absolute Convergence among Swedish LA-regionsEjsmont, Karolina, Andersson, Camilla January 2007 (has links)
The theory of economic growth predicts that poorer regions will eventually converge towards the income level of the wealthier regions (Barro & Sala-i-Martin, 2004). The aim of this Bachelor thesis is to establish if absolute convergence in Gross Regional Product (GRP) growth rates exists across LA-regions in Sweden during the period 1994-2004. The variables used in the model of absolute convergence are; the level of initial GRP per capita in the year 1994 and the growth rate of GRP per capita. The authors of this thesis find support of absolute convergence among Swedish LA-regions of 1.67 percent per year. Convergence estimations are also performed for high-, mid-, and low-performing groups of regions in respect to their income level per capita. The low-performing group of regions is in fact converging faster towards the income level of the wealthier regions in Sweden than the mid- and high-performing group. Alternative measurement of convergence is the so called sigma-convergence. The authors find that it only holds for the group of high-performing regions. However, this measurement cannot be considered reliable, as the existence of absolute convergence is necessary for sigma-convergence, but it is not sufficient. / Ekonomisk tillväxtteori förutspår att fattigare regioner med tiden kommer att konvergera mot samma inkomst nivå som rikare regioner har (Barro & Sala-i-Martin, 2004). Syftet med denna Kandidatuppsats är undersöka ifall det förekommer betingad konvergenstillväxt av Brutto Regional Produkt (BRP) nivåer mellan svenska LA-regioner under perioden 1994-2004. Variablerna som används i modellen för betingad konvergens är den ursprungliga nivån av BRP per capita under år 1994, och tillväxtnivån av BRP per capita under perioden 1994-2004. Författarna av denna uppsats har funnit stöd för betingad konvergens bland svenska LA-regioner med en konvergenstakt på 1,67 procent per år. En estimering av konvergens är därtill utförd för hög-, mellan- och lågpresterande grupper av regioner med respekt till deras inkomstnivå per capita. Den lågpresterande gruppen har en snabbare konvergeringstakt mot den inkomstnivå de rikare regionerna i Sverige har, än vad de mellan- och högpresterande grupperna. Ett alternativt mått på konvergens är den så kallade sigma-konvergensen. Författarna finner att detta mått endast håller för gruppen av högpresterande regioner. Emellertid kan inte detta mått räknas som tillförlitligt, då förekomsten av betingad konvergens är nödvändigt för sigma-konvergens, men det är inte tillräckligt.
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Nutrient sources for excessive growth of benthic algae in Lake Ontario as inferred by the distribution of SRPMartin, Grace Marion January 2010 (has links)
Total phosphorus concentrations in the open waters of the Laurentian Great Lakes are currently at or beneath target concentrations set by international agreement. Despite the success of phosphorus loading controls in remediating nearshore eutrophication problems in the past, nuisance growth of Cladophora has recently returned to the lower Great Lakes. This thesis examines soluble reactive phosphorus (SRP) in a northwestern segment of Lake Ontario to assess whether allochthonous or autochthonous sources of phosphate lead to localized areas of PO43- enrichment that may help to explain the seemingly paradoxical resurgence of Cladophora. As SRP is often an overestimate of PO43- in P-limited waters, measures of SRP made with the standard method were compared with measures of SRP made with modified methods (i.e., using dialysis and magnesium-induced co-precipitation) designed to more accurately measure phosphate when it was expected to be at low concentrations. Measures of SRP made with standard and modified methods did not differ, however, SRP was 1 to 3 orders of magnitude higher than a more sensitive steady-state radiobioassay for PO43- used for comparison in offshore waters. Although the utility of SRP is limited when phosphate concentrations are very low, SRP is useful to measure localized areas of phosphate enrichment, and its relative concentrations can be compared in time and space.
To quantify the degree to which allochthonous inputs and dreissenids contribute to PO43- concentrations that permit Cladophora growth, intensive sampling for SRP was carried out prior to, during and following the Cladophora growing season. SRP was higher in the nearshore than offshore and near the mouth of a large tributary and a treated wastewater outfall than in samples from other locations along the shoreline, but only in the spring and autumn. Phosphate turnover times indicated lower P-limitation in the nearshore and near local inputs versus the offshore. Higher concentrations of SRP were measured in samples taken 15 cm and 50 cm above dreissenid mussel-beds than in those obtained at corresponding depths over other substrata and from higher up in the water column through the Cladophora growing season, while Chl a concentrations displayed the reverse trend. These results suggest that PO43- excreted by dreissenids could be more important in time and space than external inputs in supporting nuisance Cladophora growth in the current nearshore environment. Continued research and monitoring of P dynamics in the nearshore combined with model approaches should better predict whether more stringent P controls would be effective in managing Cladophora growth.
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Hur korrelerar GIH:s Pyramidtest med VO2max på rullband för elitorienterare?Edlund, Elin, Wiik, Robert January 2011 (has links)
Syfte och frågeställningar Syftet med studien var att undersöka för elitorienterare resultaten vid och korrelationen mellan ett så kallat 5 minuters pyramidtest (5MPT) och ett maximalt test för bestämning av maximalt syreupptag (VO2max) på rullband. Frågorna vi ställde oss var: Vilken korrelation föreligger mellan 5MPT och ett bestämt VO2max på rullband hos elitorienterare? Hur ser en jämförelse ut mellan uppmätt samt beräknat VO2max? Vilken är reliabiliteten för 5MPT? Hur ser ekvationen ut för att beskriva sambandet mellan dessa två olika maxtester? Metod I valideringsstudien deltog 16 elitorienterare (6 kvinnor och 10 män) i åldrarna 17 till 37 år. De två testerna som genomfördes var 5MPT och bestämning av VO2max på rullband. 5MPT är ett skytteltest som är fem minuter långt, där testpersonen (tp) tar sig fram och tillbaka mellan två stolpar (sträcka 5.5 m) där en vertikal trappa (formad likt en pyramid) passeras under varje vända. Antalet vändor, skattad ansträngning samt hjärtfrekvens (HF) registrerades. Utvecklad power (effekt) erhölls genom produkten av vikt, gravitation, antal vändor, höjd på högsta plinten (0,62 m) dividerat med total duration i 5MPT. Testet för att bestämma VO2max utfördes med löpning på ett motordrivet rullband. Under den första minuten av testet sprang tp på en hastighet av 8km/h (kvinnor) respektive10km/h (män) utan lutning. För varje minut ökades hastigheten med 1km/h. Lutningen höjdes med en grad efter minut ett och därefter med 0,5 grader/minut. Testet pågick till dess tp nått sin VO2max. Var 15:e sekund registrerades tp:s HF, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) och respiratorisk kvot (RER) med hjälp av ett datoriserat syreupptagningssystem. Resultat Korrelationen var signifikant och hög (r = 0,89, p<0,0001) mellan utvecklad power på 5MPT och VO2max (l/min) och även mellan antalet vändor på 5MPT och VO2max (l/min) (r = 0,89, p<0,0001) på detta material av elitorienterare. Följande formler, baserade på resultaten från elitorienterarna, kan användas för att predicera VO2max efter genomfört 5MPT: VO2max (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTVÄNDOR – 74,447) / 9,7668 Slutsats 5MPT uppvisar en stark korrelation med bestämd VO2max sett till power och/eller antalet genomförda vändor. Beräkningsformler för prediktion av VO2max har varit möjligt att beskriva. Se resultatdelen för andra resultat och samband mellan 5MPT och VO2max. / Abstract Aim The aim of this study was to investigate for elite orienteers the results in and the correlation between a so called 5-minutes-pyramid test (5MPT) and a specific maximum oxygen uptake test (VO2max) on a treadmill. The questions we asked ourselves were: Which correlation exists between 5MPT and a specific VO2max on the treadmill for elite orienteers? How would a comparison look like between measured and estimated VO2max? What is the reliability for the 5MPT? How would an equation look like that describe the correlation above? Method In the validity the study 16 elite orienteers (6 women and 10 men) aged 17 to 37 years participated. The two tests that have been carried out were the 5MPT and determined VO2max during running on a treadmill. The 5MPT is a 5-minute-shuttle test, in which the participant moves back and forth in a short interval (5.5 m) over boxes (highest height: 0.62) formed like a pyramid. Power in the pyramid test (5MPTPOWER) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. To determine VO2max the method running on a treadmill was performed. During the first minute the running speed was 8km/h (women)/10 km/h (men) without elevation. Each minute the velocity increased with 1 km/h. The elevation increased with 1 degree after the first minute and thereafter with 0,5 degrees/minute. The test was finished when the participant had reached her VO2max. Every 15 second the participants heart rate, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) and RER, was registered by means of an online system. Results The correlation between the developed power of the 5MPT and measured VO2max (l/min) was high (r = 0.89, p<0,0001) and also between the number of laps in the 5MPT and measured VO2max (l/min) (r = 0.89, p < 0,0001). The following formulas can be used to predict VO2max after completed 5MPT: VO2max (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTLAPS – 74,447) / 9,7668 Conclusions 5MPT show a strong correlation with VO2max determined in terms of power and/or the number of completed laps. Calculated formulas for prediction of VO2max have been possible to describe. See results section for other results and relationships between 5MPT and VO2max. / Maximal Aerobic Power versus Performance in Two Aerobic Endurance Tests among Young and Old Adults.Andersson E, Lundahl N, Wecke L, Lindblom I, Nilsson, J.
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Electronic Packaging And Environmental Test And Analysis Of An Emi Shielded Electronic Unit For Naval PlatformDevellioglu, Yucel 01 April 2008 (has links) (PDF)
The scope of this thesis is the design and verification of an electronic packaging of a device which is a subunit of a network system that is designed for combat communication in sheltering ship. According to the project requirements this device is subjected to some environmental and electromagnetic interference tests. This thesis includes design and manufacturing steps as well as vibration, shock and thermal analyses. Electromagnetic interference is examined through the design procedure and total shielding effectiveness of the device is calculated after the applications of some electromagnetic interference precautions which are given in details.
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Regional Growth in Sweden : A Study of Absolute Convergence among Swedish LA-regionsEjsmont, Karolina, Andersson, Camilla January 2007 (has links)
<p>The theory of economic growth predicts that poorer regions will eventually converge towards the income level of the wealthier regions (Barro & Sala-i-Martin, 2004). The aim of this Bachelor thesis is to establish if absolute convergence in Gross Regional Product (GRP) growth rates exists across LA-regions in Sweden during the period 1994-2004. The variables used in the model of absolute convergence are; the level of initial GRP per capita in the year 1994 and the growth rate of GRP per capita. The authors of this thesis find support of absolute convergence among Swedish LA-regions of 1.67 percent per year. Convergence estimations are also performed for high-, mid-, and low-performing groups of regions in respect to their income level per capita. The low-performing group of regions is in fact converging faster towards the income level of the wealthier regions in Sweden than the mid- and high-performing group. Alternative measurement of convergence is the so called sigma-convergence. The authors find that it only holds for the group of high-performing regions. However, this measurement cannot be considered reliable, as the existence of absolute convergence is necessary for sigma-convergence, but it is not sufficient.</p> / <p>Ekonomisk tillväxtteori förutspår att fattigare regioner med tiden kommer att konvergera mot samma inkomst nivå som rikare regioner har (Barro & Sala-i-Martin, 2004). Syftet med denna Kandidatuppsats är undersöka ifall det förekommer betingad konvergenstillväxt av Brutto Regional Produkt (BRP) nivåer mellan svenska LA-regioner under perioden 1994-2004. Variablerna som används i modellen för betingad konvergens är den ursprungliga nivån av BRP per capita under år 1994, och tillväxtnivån av BRP per capita under perioden 1994-2004. Författarna av denna uppsats har funnit stöd för betingad konvergens bland svenska LA-regioner med en konvergenstakt på 1,67 procent per år. En estimering av konvergens är därtill utförd för hög-, mellan- och lågpresterande grupper av regioner med respekt till deras inkomstnivå per capita. Den lågpresterande gruppen har en snabbare konvergeringstakt mot den inkomstnivå de rikare regionerna i Sverige har, än vad de mellan- och högpresterande grupperna. Ett alternativt mått på konvergens är den så kallade sigma-konvergensen. Författarna finner att detta mått endast håller för gruppen av högpresterande regioner. Emellertid kan inte detta mått räknas som tillförlitligt, då förekomsten av betingad konvergens är nödvändigt för sigma-konvergens, men det är inte tillräckligt.</p>
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Beeinflussung von geschweißten Auftragschichten durch instationäre Gasströme im Plasma-Pulver-SchweißprozessEbert, Lars 11 March 2011 (has links) (PDF)
In der vorliegenden Arbeit wurde untersucht, wie sich instationäre Plasma- und Fördergasvolumenströme nutzen lassen, um den Plasma-Pulver-Auftragschweißprozess in seiner Gesamtheit zu beeinflussen.
Dabei wurden die Veränderungen in der Lichtbogencharakteristik, der Pulverzuführung und insbesondere dem Schmelzbad analysiert und in einem theoretischen Prozessmodell zusammengefasst. Die gewonnenen Ergebnisse und die aufgezeigten Wirkzusammenhänge konnten in der Folge dazu genutzt werden, die Hartstoffverteilung in Pseudolegierungen und den mikrostrukturellen Aufbau geschweißter konventioneller Hartschichten zu modifizieren. / In the present studies it is examined, how unsteady gas flows can be used to modify the plasma transfer arc welding process in its entirety. In the first step it was analysed in which different ways non-steady-state plasma and transport gas flows influence the arc characteristics, the powder transport and the melt bead properties. With the obtained results a theoretical model was developed, to describe the observed behaviours and understand the coherences. Subsequently the preliminary findings were used to alter the distribution of tungsten-carbide in a welded hardface composite coating and to modify the microstructure of a conventional alloy welded with the plasma transfer arc process.
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