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Vysokovýklopná lopata pro nakladač / High loading shovel for loaderRajdl, Marek January 2015 (has links)
This diploma thesis deals with design of the high loading shovel for the loader Komatsu WA380. The aim is to find constructional solutions of the high loading shovel for a minimal dumping height of 4 500 mm, for the bucket width of 3 000 mm and for the bucket volume of 5 m3. The thesis contains a brief description of the high loading shovel and description of basic constructional components. It also contains choices of basic constructional components, a calculation of the necessary force to tilt the bucket and a static analysis. Stress control of the bucket, the frame and the pegs forms the final part of the thesis. The thesis is accompanied by the necessary technical drawings.
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CHARACTERIZATION OF NANOCARBON-REINFORCED AND NEAT ADHESIVES IN BONDED SINGLE LAP JOINTS UNDER STATIC AND IMPACT LOADINGSSoltannia, Babak 16 August 2013 (has links)
The effects of high loading rates (HLR), and nano reinforcement on the mechanical response of adhesively-bonded SLJs with composite adherends, subjected to different loading (strain) rates are systematically investigated. The results are then compared to those of neat thermoset resin and thermo-plastic adhesive. More specifically, nano-reinforced and neat resin bonded joints mating carbon/epoxy and glass/epoxy adherends were subjected to tensile loadings under 1.5 and 3 mm/min and tensile impacts at a loading rate of 2.04E+5 mm/min. In some cases, additional tests were conducted under 15, 150, and 1500 mm/min to obtain additional properties gained using the nano-reinforcements for use in the further numerical investigations. The HLR tests were conducted, using a modified instrumented pendulum equipped with a specially designed impact load transfer apparatus. The dispersion of nanoparticles was facilitated using a mechanical stirrer and a three-roll mill machine. The failure mechanisms were studied with a scanning electron microscope.
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Numerical Investigation of Subsonic Axial-Flow Tandem Airfoils for a Core Compressor RotorMcGlumphy, Jonathan 18 February 2008 (has links)
The tandem airfoil has potential to do more work as a compressor blade than a single airfoil without incurring significantly higher losses. Although tandem blades are sometimes employed as stators, they have not been used in any known commercial rotors. The goal of this work is to evaluate the aerodynamic feasibility of using a tandem rotor in the rear stages of a core compressor. As such, the results are constrained to shock-free, fully turbulent flow. The work is divided into 2-D and 3-D simulations. The 3-D results are subject to an additional constraint: thick endwall boundary layers at the inlet.
Existing literature data on tandem airfoils in 2-D rectilinear cascades have been compiled and presented in a Lieblein loss versus loading correlation. Large scatter in the data gave motivation to conduct an extensive 2-D CFD study evaluating the overall performance as a function of the relative positions of the forward and aft airfoils. CFD results were consistent with trends in the open literature, both of which indicate that a properly designed tandem airfoil can outperform a comparable single airfoil on- and off-design. The general agreement of the CFD and literature data serves as a validation for the computational approach.
A high hub-to-tip ratio 3-D blade geometry was developed based upon the best-case tandem airfoil configuration from the 2-D study. The 3-D tandem rotor was simulated in isolation in order to scrutinize the fluid mechanisms of the rotor, which had not previously been well documented. A geometrically similar single blade rotor was also simulated under the same conditions for a baseline comparison. The tandem rotor was found to outperform its single blade counterpart by attaining a higher work coefficient, polytropic efficiency and numerical stall margin. An examination of the tandem rotor fluid mechanics revealed that the forward blade acts in a similar manner to a conventional rotor. The aft blade is strongly dependent upon the flow it receives from the forward blade, and tends to be more three-dimensional and non-uniform than the forward blade. / Ph. D.
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High molecular sieve loading mixed matrix membranes for gas separationsAdams, Ryan Thomas 13 January 2010 (has links)
Traditional gas separation technologies are thermally-driven and can have adverse environmental and economic impacts. Gas separation membrane processes are not thermally-driven and have low capital and operational costs which make them attractive alternatives to traditional technologies. Polymers are easily processed into large, defect-free membrane modules which have made polymeric membranes the industrial standard; however, polymers show separation efficiency-productivity trade-offs and are often not thermally or chemically robust. Molecular sieves, such as zeolites, have gas separation properties that exceed polymeric materials and are more thermally and chemically robust. Unfortunately, formation of large, defect-free molecular sieve membranes is not economically feasible. Mixed matrix membranes (MMMs) combine the ease of processing polymeric materials with the superior transport properties of molecular sieves by dispersing molecular sieve particles in polymer matrices to enhance the performance of the polymers.
MMMs with high molecular sieve loadings were made using polyvinyl acetate (PVAc) and various molecular sieves. Successful formation of these MMMs required substantial modifications to low loading MMM formation techniques. The gas separation properties of these MMMs show significant improvements over PVAc properties, especially for high pressure mixed carbon dioxide-methane feeds that are of great industrial relevance.
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The Effects Of Seed Sludge Type And Anoxic/aerobic Period Sequence On Aerobic Granulation And Cod, N Treatment PerformanceErsan, Yusuf Cagatay 01 January 2013 (has links) (PDF)
The aim of this master thesis study was improvement of the required operational conditions for aerobic granulation in sequencing batch reactors (SBRs).
In the first part of the study, membrane bioreactor sludge (MBS) and conventional activated sludge (CAS), were used to investigate the effect of suspended seed sludge type on granulation in SBRs. The MBS granules were found to be advantageous in terms of size, resistance to toxic effects, stability and recovery compared to CAS granules. During non-inhibitory conditions, sCOD removal efficiencies were 70± / 13% and 67± / 11% for MBS and CAS, and total nitrogen (TN) removal efficiencies were 38± / 8% and 26± / 8%, respectively.
In the second part of the study, the effects of period sequence (anoxic-aerobic and aerobic-anoxic) on aerobic granulation from MBS, and sCOD, N removal efficiencies were investigated. Granules developed in anoxic-aerobic period sequence were more stable and larger (1.8-3.5 mm) than granules developed in aerobic-anoxic sequence. Under steady conditions, almost 95% sCOD, 90% Total Ammonia Nitrogen (TAN) and around 39-47 % of TN removal was achieved. Almost 100% denitrification in anoxic period was achieved in anoxic-aerobic period sequence and it was observed around 40% in aerobic-anoxic period sequence.
The effects of influent sulfate (from 35.1 mg/L to 70.2 mg/L) on treatment efficiencies of aerobic granules were also investigated. The influent SO42- concentrations of 52.6 mg/L to 70.2 mg/L promoted sulfate reduction. The produced sulfide (0.24 mg/L to 0.62 mg/L) inhibited the ammonia-oxidizing bacteria (AOB) performance by 10 to 50%.
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Vysokovýklopná lopata / High loading shovelPetro, Roman January 2009 (has links)
This diploma thesis solves construction project high dumping shovel for back hoe loader New Holland B100 and B110. There are described operating conditions in the introduction, transport material and technical parameters for back hoe loader B100, B110. There are mentioned possible construction’s solutions and own design. Follow the kinematics analysis of material’s dumping and the static analysis on shovel and frame. This is connected with following peg’s control and the solidity analysis of shovel and frame for different load cases, where the MFE was used
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Vysokovýklopná lopata pro teleskopický manipulátor LM1345 TURBO / High loading shovel for telehandlers LM1345 TurboDragan, Lukáš January 2014 (has links)
This diploma thesis follow up the structural design high loading shovel for telehandlers LM1345 TURBO by New Holland. The introduction processed basic characteristics and parameters of the machine and material which will be in operation most frequently transported by the shovel. The work includes static analysis load acting on the shovel and frame when the machine is operating, strength calculations and the design and control of the peg.
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Evidence-Based High-Loading Exercise as a Novel Therapeutic Training Approach in Achilles TendinopathyRadovanović, Goran 19 November 2024 (has links)
Sehnenverletzungen machen ca. 30 % der muskuloskelettalen Beschwerden aus. Repetitive Überlastung wird häufig als Ursache diskutiert. Dabei entstehende strukturelle Schäden können die Kapazität der Sehne, mechanische Belastung zu tolerieren, reduzieren. Das exzentrische Protokoll nach Alfredson sowie das „heavy slow resistance training“ sind häufig genutzte Formen der Trainingstherapie. Jedoch zeigen diese Protokolle bisher kaum Nachweise für strukturelle Anpassung. Eine trainingsinduzierte Zunahme der Sehnensteifigkeit könnte die Sehne widerstandsfähiger machen und vor Überlastung schützen, da die Beanspruchung (Sehnendehnung) bei gegebener Belastung reduziert wird. Bei gesunden Probanden führte das „high-loading“ Protokoll, das mit einer hohen Dehnungsmagnitude arbeitet, ausgelöst durch ca. 90 % der maximal willkürlichen Kontraktionskraft der Plantarflexoren, sowie einer Dauer von 3 Sek., zu positiven strukturellen Anpassungen. Die vorliegende Arbeit zeigt erstmals, dass sich tendinopathische Achillessehnen bei ausreichend hohem mechanischen Stimulus ähnlich gesunden Sehnen anpassen. Im Vergleich zum exzentrischen Training sowie passiver Therapie führte nur das high-loading Protokoll zu einer Hypertrophie der Sehne sowie einer Zunahme der Sehnensteifigkeit, während es in allen drei Gruppen gleichermaßen zu klinisch-funktionellen Verbesserungen kam. Das dabei angewandte mobile Trainingsgerät bewies in einer separaten Studie exzellente Reliabilität sowie Effektivität (Kraft/Sprunghöhe). Weiters wurden Asymmetrien zwischen der betroffenen/nicht-betroffenen Seite untersucht. Größtenteils zeigten sich im Vergleich zu Gesunden ähnlich ausgeprägte Asymmetrien. Die Effekte auf diese Asymmetrien durch Training waren eher gering. Eine Reduzierung der Asymmetrien ging nicht notwendigerweise einher mit einer klinisch-funktionellen Verbesserung. Insgesamt liefern die Ergebnisse wichtige Erkenntnisse bezüglich einer neuartigen Behandlungsmethode der Achillestendinopathie, die durch die hervorgerufene Verbesserung von Sehneneigenschaften sowohl für die Rehabilitation als auch Prävention zu empfehlen ist. / Tendon injuries account for approximately 30 % of musculoskeletal consultations. Repetitive overload is identified commonly as initial cause implicating structural impairments. Hence, the capacity of the tendon to tolerate mechanical load might be attenuated. In Achilles tendinopathy, Alfredsons ´eccentric exercise protocol and heavy slow resistance training are frequently applied exercise interventions both leading to clinical and functional improvements. However, evidence for eliciting structural adaptation is lacking. An exercise-induced increase in tendon stiffness might improve the tendon `s capacity to tolerate loading and thus reduce future damage as tendon strain at a given force is reduced. In healthy subjects, the high-loading protocol applying high tendon strain induced by highly intensive muscle contractions (i.e., at 90 % of maximum voluntary isometric contraction) with 3 seconds time-under-tension has led to positive adaptations (i.e., increased cross-sectional area and stiffness). This thesis first provides evidence that tendinopathic Achilles tendons do adapt comparable to healthy tendons given that an adequate mechanical stimulus was applied. High-loading led to tendon hypertrophy and an increase in tendon stiffness compared to eccentric exercise or passive therapy, while clinical/functional improvements have been detected in all the three groups. In a separate trial, the applied mobile training device showed excellent reliability and effectiveness (strength/jump height). Further, inter-limb asymmetries have been investigated showing comparable levels except for vascularization compared to healthy subjects. Therapeutic interventions had only small effects regarding pronounced asymmetry reductions whereas a reduction in asymmetry did not necessarily correlate with an improvement in tendon health.
In conclusion, the findings of the present thesis provide valuable evidence for high-loading as a novel exercise treatment in Achilles tendinopathy.
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