National Repository of Grey Literature 9 records found  Search took 0.05 seconds. 
The effect of pressure on the electrode system in lead acid batteries with experimental glass fibers aditives electrodes
Fryda, Daniel ; Vaculík, Sebastian (referee) ; Bača, Petr (advisor)
This Master’s thesis deals with the lead-acid batteries, which are alternativ power supply. The lead-acid batteries are the oldest type of battery cells. This lead-acid batteries have a great use in hybrid electric vehicles (HEVs), which operate in different modes of vehicle operation. These modes correspond to the reactions taking place during discharging and charging the battery. The lead-acid batteries in hybrid electric vehicles work in mode PSoC. The practical part of the Master`s thesis examines how the characteristics of lead-acid batteries are modified due to admixture of glass fibers into negative active material and application of pressure to the electrode system.
Effective Algorithms for High-Precision Computation of Elementary Functions
Chaloupka, Jan ; Kunovský, Jiří (referee) ; Šátek, Václav (advisor)
Nowadays high-precision computations are still more desired. Either for simulation on a level of atoms where every digit is important and inaccurary in computation can cause invalid result or numerical approximations in partial differential equations solving where a small deviation causes a result to be useless. The computations are carried over data types with precision of order hundred to thousand digits, or even more. This creates pressure on time complexity of problem solving and so it is essential to find very efficient methods for computation. Every complex physical problem is usually described by a system of equations frequently containing elementary functions like sinus, cosines or exponentials. The aim of the work is to design and implement methods that for a given precision, arbitrary elementary function and a point compute its value in the most efficent way. The core of the work is an application of methods based on AGM (arithmetic-geometric mean) with a time complexity of order $O(M(n)\log_2{n})$ 9(expresed for multiplication $M(n)$). The complexity can not be improved. There are many libraries supporting multi-precision atithmetic, one of which is GMP and is about to be used for efficent method implementation. In the end all implemented methods are compared with existing ones.
The examination of the effect of titanium dioxide on the properties of lead-acid batteries
Mlýnek, Martin ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
Despite, considerable advances in technologies for storing electrical energy, lead-acid batteries are still the most widely used these days even it was invented more than a century ago. The functionality remains the same since its invention. Today´s time puts certain pressure on improving some aspects of the functionality like, heat management, charging and discharging speed, capacity and durability etc..... This bachelor´s thesis is based on the last mentioned, Durability,. The work presents the theory of acid batteries with the history of chemical reaction, technological production processes and battery construction. It is followed by a chapter about titanium and titanium dioxide as an addition of negative active mass where all the aspects are being examined in this work.
Temperature changes in different designs of lead-acid batteries
Langer, Martin ; Libich, Jiří (referee) ; Bača, Petr (advisor)
This diploma thesis deals with lead accumulators, the possibilities of their division and the basic reactions that take place inside taking into account the design features of individual types. Both exothermic and endothermic reactions taking place at the electrode-electrolyte interface, as well as the heating of the accumulator caused by Joule losses on its internal resistance, are then discussed in more detail. However, the charging reaction is also accompanied by other internal processes of the accumulator, which are related to electrolysis, recombination of water and polarization resistance. A calorimeter made of expanded polystyrene and a measuring center with external temperature sensors are used to quantify the degree of causation of temperature changes of individual processes. In the thesis, the rate of heat loss through the walls of the calorimeter is subsequently evaluated and used to calculate the total thermal energy during cycling.
Design And Construction Of Electric Lightweight Motorcycle
Bartoš, Jiří
This work deals with designing and constructing of lightweight electro motorcycle. It has four parts. The first part deals with things connected to underframe. In the next part there are some information about traction motor. The third part deals with regulator. The last part is focused on things connected to batteries.
The examination of the effect of titanium dioxide on the properties of lead-acid batteries
Mlýnek, Martin ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
Despite, considerable advances in technologies for storing electrical energy, lead-acid batteries are still the most widely used these days even it was invented more than a century ago. The functionality remains the same since its invention. Today´s time puts certain pressure on improving some aspects of the functionality like, heat management, charging and discharging speed, capacity and durability etc..... This bachelor´s thesis is based on the last mentioned, Durability,. The work presents the theory of acid batteries with the history of chemical reaction, technological production processes and battery construction. It is followed by a chapter about titanium and titanium dioxide as an addition of negative active mass where all the aspects are being examined in this work.
The examination of the effect of titanium dioxide on the properties of lead-acid batteries
Mlýnek, Martin ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
Despite, considerable advances in technologies for storing electrical energy, lead-acid batteries are still the most widely used these days even it was invented more than a century ago. The functionality remains the same since its invention. Today´s time puts certain pressure on improving some aspects of the functionality like, heat management, charging and discharging speed, capacity and durability etc..... This bachelor´s thesis is based on the last mentioned, Durability,. The work presents the theory of acid batteries with the history of chemical reaction, technological production processes and battery construction. It is followed by a chapter about titanium and titanium dioxide as an addition of negative active mass where all the aspects are being examined in this work.
Effective Algorithms for High-Precision Computation of Elementary Functions
Chaloupka, Jan ; Kunovský, Jiří (referee) ; Šátek, Václav (advisor)
Nowadays high-precision computations are still more desired. Either for simulation on a level of atoms where every digit is important and inaccurary in computation can cause invalid result or numerical approximations in partial differential equations solving where a small deviation causes a result to be useless. The computations are carried over data types with precision of order hundred to thousand digits, or even more. This creates pressure on time complexity of problem solving and so it is essential to find very efficient methods for computation. Every complex physical problem is usually described by a system of equations frequently containing elementary functions like sinus, cosines or exponentials. The aim of the work is to design and implement methods that for a given precision, arbitrary elementary function and a point compute its value in the most efficent way. The core of the work is an application of methods based on AGM (arithmetic-geometric mean) with a time complexity of order $O(M(n)\log_2{n})$ 9(expresed for multiplication $M(n)$). The complexity can not be improved. There are many libraries supporting multi-precision atithmetic, one of which is GMP and is about to be used for efficent method implementation. In the end all implemented methods are compared with existing ones.
The effect of pressure on the electrode system in lead acid batteries with experimental glass fibers aditives electrodes
Fryda, Daniel ; Vaculík, Sebastian (referee) ; Bača, Petr (advisor)
This Master’s thesis deals with the lead-acid batteries, which are alternativ power supply. The lead-acid batteries are the oldest type of battery cells. This lead-acid batteries have a great use in hybrid electric vehicles (HEVs), which operate in different modes of vehicle operation. These modes correspond to the reactions taking place during discharging and charging the battery. The lead-acid batteries in hybrid electric vehicles work in mode PSoC. The practical part of the Master`s thesis examines how the characteristics of lead-acid batteries are modified due to admixture of glass fibers into negative active material and application of pressure to the electrode system.

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