Valvetrain four - stroke Jawa 837 engine

katedra: KSP;This thesis describes valvetrain variable timing and their use in motorcycle engines and analyzing the kinematic characteristics of the existing lifting cams dependency. Also defined designing of lifting dependence to stop valve lifter with self-defining valve clearances. The work also indicated the calculation of stresses and deformations simplified camshaft by finite element method, checking the tension in the shank of one of the valves also by finite element method.Diplomová práce popisuje ventilové rozvody s proměnným časováním a jejich užití v motocyklových motorech. Analyzuje kinematické vlastnosti stávajících zdvihových závislostí vaček. Také navrhuje zdvihovou závislost pro zástavku zdvihátek se samočinným vymezováním ventilových vůlí. Dále je v práci uveden výpočet namáhání a deformací zjednodušeného vačkového hřídele metodou konečných prvků, kontrola napětí v dříku jednoho z ventilů taktéž metodou konečných prvků

One-Piece Mini Dental Implant-Retained Mandibular Overdentures: 10-Year Clinical and Radiological Outcomes of a Non-Comparative Longitudinal Observational Study.

This study presents the first 10-year follow-up investigation of the implant survival and peri-implant outcomes of one-piece mini dental implants (MDIs) retaining mandibular implant overdentures (IODs), including marginal bone level alterations (ΔMBLs), clinical peri-implant parameters, and complications. Twenty participants with horizontally atrophied mandibles received complete dentures and four MDIs (diameter 1.8 mm) at baseline. The dentures were converted into IODs with O-ring attachments. The 10-year follow-up comprised a radiological assessment of ΔMBLs, peri-implant parameters, as well as biological and technical complications. Results from a 10-year follow-up of 14 participants showed a 100% implant survival rate for all 56 implants. The mean ΔMBL after 10 years was -1.12 ± 0.80 mm, with 49 implants classified as successful (ΔMBL < 2 mm) and 7 implants with satisfactory survival (ΔMBL 2-4 mm). Time after implant placement significantly influenced ΔMBL, with stable MBLs after 5 years. The prosthetic survival rate after 10 years was 93%. ΔMBLs were not influenced by implant position or gender but were significantly smaller in subjects older than 65 years. Conclusively, one-piece MDIs with O-ring attachments offer a reliable treatment option for horizontally atrophied mandibles after 10 years, with high implant and prosthetic survival rates, potentially benefiting from advanced age regarding peri-implant bone stability

Pincer and Macrocyclic Pyridylidene Amide (PYA) AuIII Complexes.

Gold-based homogeneous catalysis is dominated by redox neutral AuI systems. Redox-active gold-based catalysts are less common, principally because of redox cycles between AuI and AuIII being hampered by unfavorable potentials. We report gold(III) complexes containing pincer-based, donor-flexible pyridylidene amide (PYA) ligands to address these issues. These complexes act as electron reservoirs through two limiting resonance structures consisting of either soft, imine coordination sites or harder, zwitterionic amide donors. We further alter the donor properties by using the ortho-, meta-, and para-pyridylidene amide variants of the PYA pincer arms. These bis-PYA pincer ligands exhibited a high contribution of amide coordination in the solid-state of the gold(III) complexes; however, the solution data suggests a high contribution from the neutral L-type resonance forms. This L-type contribution, primarily shown through cyclic voltammetry studies, prevents reversible gold(III) reduction and also disfavors abstraction of the ancillary chloride ligand. Furthermore, a novel macrocyclic-PYA ligand is introduced, which shows secondary metal-ligand interactions

Experimental Electric Vehicle eŠus Gen2

In the introduction to the article, the conception and development of an experimental electric vehicle is described. It is followed by a description of the used mechanical and electrical components in combination with the design solutions of sub-units, such as the vehicle powertrain and traction battery. The choice of components and design solutions is evaluated here with regard to the current trends in the development of battery electric vehicles. V úvodu článku je popsán vznik a koncepce experimentálního elektromobilu. Následuje popis použitých mechanických a elektrických komponent v kombinaci s konstrukčními řešeními dílčích celků jako je např. pohonné ústrojí vozidla nebo trakční baterie vozidla. Volba použitých komponent a konstrukčních řešení je zde zhodnocena vzhledem k současným trendům ve vývoji elektromobilů. Článek obsahuje i simulace dynamiky vozidla pro vybrané elektromotory se kterými se počítalo pro zástavbu do vozidla