Combustion Engines with Gasoline Direct Injection

Tato bakalářská práce řeší problematiku přímého vstřikování benzínu u zážehových motorů. Uvádí základní přehled škodlivých látek výfukových plynů, funkce jednotlivých komponent palivového systému a jejich vývoj. Vysvětluje princip činnosti, výhody a nevýhody oproti nepřímému vstřiku. V závěru se zabývá využitím přímého vstřikování v budoucnosti.This bachelor thesis deals with the problematics of direct gasoline injection in petrol engines. It presents basic overview of pollutants from exhaust gases, functions of individual components of fuel system and their development. Next chapter explains the principle of operation, advantages and disadvantages compared to port fuel injection. The last section is focused on use of direct injection in the future.

Impact of climate change on hydrological regimes and water resource management in the Rhine basin”,

Abstract. The International Commission for the Hydrology of the Rhine basin (CHR) has carried out a research project to assess the impact of climate change on the river flow conditions in the Rhine basin. Along a bottom-up line, different detailed hydrological models with hourly and daily time steps have been developed for representative sub-catchments of the Rhine basin. Along a topdown line, a water balance model for the entire Rhine basin has been developed, which calculates monthly discharges and which was tested on the scale of the major tributaries of the Rhine. Using this set of models, the effects of climate change on the discharge regime in different parts of the Rhine basin were calculated using the results of UKHI and XCCC GCM-experiments. All models indicate the same trends in the changes: higher winter discharge as a result of intensified snow-melt and increased winter precipitation, and lower summer discharge due to the reduced winter snow storage and an increase of evapotranspiration. When the results are considered in more detail, however, several differences show up. These can firstly be attributed to different physical characteristics of the studied areas, but different spatial and temporal scales used in the modelling and different representations of several hydrological processes (e.g., evapotranspiration, snow melt) are responsible for the differences found as well. Climate change can affect various socio-economic sectors. Higher temperatures may threaten winter tourism in the lower winter sport areas. The hydrological changes will increase flood risk during winter, whilst low flows during summer will adversely affect inland navigation, and reduce water availability for agriculture and industry. Balancing the required actions against economic cost and the existing uncertainties in the climate change scenarios, a policy of 'noregret and flexibility' in water management planning and design is recommended, where anticipatory adaptive measures in response to climate change impacts are undertaken in combination with ongoing activities. Present address

Oscillations, Intercellular Coupling, and Insulin Secretion in Pancreatic β Cells

Insulin is a potent metabolic regulator that is released by pancreatic beta-cells, which respond to body glucose concentrations. Here the authors explain the physiological basis of insulin release

Mice Deficient in GEM GTPase Show Abnormal Glucose Homeostasis Due to Defects in Beta-Cell Calcium Handling

Glucose-stimulated insulin secretion from beta-cells is a tightly regulated process that requires calcium flux to trigger exocytosis of insulin-containing vesicles. Regulation of calcium handling in beta-cells remains incompletely understood. Gem, a member of the RGK (Rad/Gem/Kir) family regulates calcium channel handling in other cell types, and Gem over-expression inhibits insulin release in insulin-secreting Min6 cells. The aim of this study was to explore the role of Gem in insulin secretion. We hypothesised that Gem may regulate insulin secretion and thus affect glucose tolerance in vivo

A Folding Pathway-Dependent Score to Recognize Membrane Proteins

While various approaches exist to study protein localization, it is still a challenge to predict where proteins localize. Here, we consider a mechanistic viewpoint for membrane localization. Taking into account the steps for the folding pathway of α-helical membrane proteins and relating biophysical parameters to each of these steps, we create a score capable of predicting the propensity for membrane localization and call it FP3mem. This score is driven from the principal component analysis (PCA) of the biophysical parameters related to membrane localization. FP3mem allows us to rationalize the colocalization of a number of channel proteins with the Cav1.2 channel by their fewer propensities for membrane localization

Turbocharger Vibrations Generated by Internal Combustion Engine

The content of this master’s thesis is the issue of turbocharger vibrations due to excitation from the internal combustion engine. The theoretical part deals with the noise and vibrations generated by turbochargers and internal combustion engines. It also discusses the effect of vibration on the turbocharger and its individual parts, including the effect of the internal combustion engine. Subsequently, a turbocharger model is created in ADAMS software, the rotor response in turbocharger operating speeds to various excitation frequencies is analyzed and finally the safety of fluid bearings is evaluated and modifications to reduce vibrations are proposed