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1. Smartphone Voice Calls Provide Early Biomarkers of Parkinsonism in Rapid Eye Movement Sleep Behavior Disorder.

Author

Illner, Vojtěch, Novotný, Michal, Kouba, Tomáš, Tykalová, Tereza, Šimek, Michal, Sovka, Pavel, Švihlík, Jan, Růžička, Evžen, Šonka, Karel, Dušek, Petr, and Rusz, Jan

Abstract

Background: Speech dysfunction represents one of the initial motor manifestations to develop in Parkinson's disease (PD) and is measurable through smartphone. Objective: The aim was to develop a fully automated and noise‐resistant smartphone‐based system that can unobtrusively screen for prodromal parkinsonian speech disorder in subjects with isolated rapid eye movement sleep behavior disorder (iRBD) in a real‐world scenario. Methods: This cross‐sectional study assessed regular, everyday voice call data from individuals with iRBD compared to early PD patients and healthy controls via a developed smartphone application. The participants also performed an active, regular reading of a short passage on their smartphone. Smartphone data were continuously collected for up to 3 months after the standard in‐person assessments at the clinic. Results: A total of 3525 calls that led to 5990 minutes of preprocessed speech were extracted from 72 participants, comprising 21 iRBD patients, 26 PD patients, and 25 controls. With a high area under the curve of 0.85 between iRBD patients and controls, the combination of passive and active smartphone data provided a comparable or even more sensitive evaluation than laboratory examination using a high‐quality microphone. The most sensitive features to induce prodromal neurodegeneration in iRBD included imprecise vowel articulation during phone calls (P = 0.03) and monopitch in reading (P = 0.05). Eighteen minutes of speech corresponding to approximately nine calls was sufficient to obtain the best sensitivity for the screening. Conclusion: We consider the developed tool widely applicable to deep longitudinal digital phenotyping data with future applications in neuroprotective trials, deep brain stimulation optimization, neuropsychiatry, speech therapy, population screening, and beyond. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Microstructural and Mechanical Characterization of the Laser Beam Welded SAF 2507 Super-Duplex Stainless Steel.

Author

Šimeková, Beáta, Dománková, Mária, Kovaříková, Ingrid, Kovačócy, Pavel, Martinkovič, Maroš, Šimek, Michal, and Ciuła, Luke

Subjects
STAINLESS steel welding, LASER welding, SHIELDING gases, WELDING, CORROSION resistance
Abstract

The influence of laser beam welding parameters (power, welding rate, focusing, head oscillation, shielding gas) on the microstructure, mechanical properties and corrosion resistance of the super-duplex stainless steel SAF 2507 was studied in this paper. The presented results clearly report the effects of welding parameter changes on the character of the steel's microstructure. The presence of secondary phase M2N in weld metals has an important influence on their mechanical properties. Optimal mechanical properties, an acceptable ferrite/austenite ratio, and the minimum content of M2N nitride required in the weld metal were acquired in the case the following application: 1100 W power, welding speed of 10 mm/s, focusing of 4 mm, and pure nitrogen shielding gas (20 L/min). [ABSTRACT FROM AUTHOR]

Published
2024
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8. Analysis of critical battery parameters for space applications

Author

Šimek, Michal and Šimek, Michal

Abstract

This thesis deals with the analysis of lithium-ion batteries from the point of view of temperature. The aim is to find out at which temperature and C value the lithium plating process starts in the battery by means of non-destructive methods. This process is undesirable for the functioning of lithium-ion batteries as it causes capacity reduction and cell degradation. In this study, commercial cells from GOMspace were selected as the test batteries. GOMspace will be able to use the results of the research to optimize its devices while avoiding lithium plating, which will increase battery life.

Published
2022

9. Tandem Anionic Sigmatropic Rearrangement/Radical Reactions and Their Application Toward the Total Synthesis of Natural Products

Author

Šimek, Michal, Jahn, Ullrich, Urban, Milan, and Švenda, Jakub

Subjects
Ganoderma meroterpenoid, radical reaction, cyclization, 5-endo-trig, Rearrangement, Single-electron oxidation
Abstract

The thesis describes the development of unprecedented tandem reactions merging anionic oxy-Cope rearrangement with single-electron transfer oxidation of thus generated metal enolates by ferrocenium hexafluorophosphate. The formed α-carbonyl radicals were utilized in oxygenation reactions by coupling them with persistent radical TEMPO, furnishing rearranged α-aminoxy carbonyl compounds. Suitable reaction conditions and factors influencing the rearrangement aptitudes were determined. The obtained polyfunctional products proved versatile in diversifications by polar reactions producing diverse scaffolds. Furthermore, rearranged α-aminoxy carbonyls with a double bond located in the δ-position of the carbonyl group are applicable in all-carbon 5-endo-trig radical cyclizations governed by the persistent radical effect. Despite the low kinetic rate, this rare cyclization mode furnished a number of substituted cyclopentanes. The reaction scope, including competitive cyclization modes, was studied. The developed methodology was utilized as a key reaction step to synthesize appropriately substituted cyclopentane core in a divergent approach to meroterpenoid fungal metabolites isolated from Ganoderma applanatum. The accomplished synthesis of applanatumols V and W and their epimers enabled the correction of...

Published
2022

12. Deacylative Homolysis of Ketone C(sp3)–C(sp2) Bonds: Streamlining Natural Product Transformations

Author

Šimek, Michal, Mahato, Sujit, Dehnert, Brady W., and Kwon, Ohyun

Abstract

The homolytic cleavage of C–C bonds adjacent to specific functional groups has lately emerged as a versatile approach for molecular diversification. Despite the ubiquity and synthetic utility of ketones, radical fragmentation of their α-C–C bonds has proven to be a formidable challenge. Here, we present a broadly applicable deacylative strategy designed to homolytically cleave aliphatic ketones of various complexities, including transformations of cycloalkanones into carboxylic acids tethered to C-centered free radicals that can be engaged in diverse radical-based processes. The method involves ketone activation through treatment with hydrogen peroxide, yielding gem-dihydroperoxides. Subsequent single-electron-transfer reduction mediated by a low-valent metal complex generates alkyl radicals that can be captured selectively with a radicophile of choice, including through catalytic cross-coupling. The logic of our deacylative functionalization is exemplified by the total synthesis of 14 natural products, one analogue, and two drugs starting from readily available natural products, showcasing its transformative power in complex settings. This approach obviates the need for complex reagents and allows the controlled conversion of ketones to reconstructed products, making the process highly applicable across a spectrum of domains.

Published
2025
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15. INFLUENCE OF ELECTRON BEAM OSCILLATION AND HEAT INPUT ON THE QUALITY OF SAF 2205 DUPLEX STAINLESS STEEL WELDS.

Author

ŠIMEKOVÁ, Beáta, KOVAŘÍKOVÁ, Ingrid, HODÚLOVÁ, Erika, and ŠIMEK, Michal

Subjects
STAINLESS steel welding, DUPLEX stainless steel, ELECTRON beam welding, ELECTRON beams, ULTRASONIC testing, SCANNING electron microscopes
Abstract

This paper investigates the weldability, metallurgical and mechanical properties of 5 mm thickness plate of SAF 2205 duplex stainless steel joints by electron beam welding (EBW) process. The excellent properties of duplex stainless steels (DSS) are due to their strict composition control and microstructural balance. The ferrite/austenite ratio is often upset in duplex stainless steel weld metals owing to the rapid cooling rates correlated with welding. To achieve the required ferrite/austenite balance and good properties, the welding process and the heat input must be controlled. Each joint obtained by electron beam welding and their individual sub-regions through thickness were characterised by optical microscopy. Distribution of elements in various areas was evaluated by scanning electron microscope (SEM/EDX). On the particular samples was observed microhardness and ferrite/austenite balance. Ultrasonic non-destructive testing was used for quality assessment of EBW duplex steel joints. Electron beam welding has produced weld joints with a significant decrease in austenite zone size. The ferrite/austenite balance of both weld metal and heat affected zone are influenced by heat input which is a function of welding process. This work describes the possibilities how to achieve the weld joints of high quality by using the optimal welding parameters [1,2]. [ABSTRACT FROM AUTHOR]

Published
2021

18. Asymmetric organocatalytic synthesis of tertiary azomethyl alcohols: key intermediates towards azoxy compounds and α- hydroxy-β-amino esters

Author

Carmona, José A., Gonzalo, Gonzalo de, Serrano, Inmaculada, Crespo-Peña, Ana, Šimek, Michal, Fernández, Rosario, and Lassaletta, José M.

Abstract

A series of peracylated glycosamine-derived thioureas has been synthesized and its behavior as bifunctional organocatalysts has been tested in the enantioselective nucleophilic addition of formaldehyde tert-butyl hydrazone to aliphatic α-keto esters for the synthesis of tertiary azomethyl alcohols. Using the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy- β-D-glucosamine derived 3,5-bis-(trifluoromethyl)phenyl thiourea the reaction could be accomplished with high yields (75- 98%) and moderate enantioselectivities (50-64% ee). Subsequent high-yielding and razemization-free tranformations of both aromatic- and aliphatic-substituted diazene products in one pot fashion provides a direct entry to valuable azoxy compounds and α-hydroxy-β-amino esters

Published
2017

20. Asymmetric organocatalytic synthesis of tertiary azomethyl alcohols: key intermediates towards azoxy compounds and α-hydroxy-β-amino esters

Author

Universidad de Sevilla. Departamento de Química Orgánica, Carmona, José A., Gonzalo Calvo, Gonzalo de, Serrano Vallez, Inmaculada, Crespo-Peña, Ana, Šimek, Michal, Monge Fernández, David, Fernández, Rafael, Lassaletta, José M., Universidad de Sevilla. Departamento de Química Orgánica, Carmona, José A., Gonzalo Calvo, Gonzalo de, Serrano Vallez, Inmaculada, Crespo-Peña, Ana, Šimek, Michal, Monge Fernández, David, Fernández, Rafael, and Lassaletta, José M.

Abstract

A series of peracylated glycosamine-derived thioureas have been synthesized and their behavior as bifunctional organocatalysts has been tested in the enantioselective nucleophilic addition of formaldehyde tert-butyl hydrazone to aliphatic α-keto esters for the synthesis of tertiary azomethyl alcohols. Using the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β-d-glucosamine derived 3,5-bis-(trifluoromethyl)phenyl thiourea the reaction could be accomplished with high yields (75-98%) and moderate enantioselectivities (50-64% ee). Subsequent high-yielding and racemization-free tranformations of both aromatic- and aliphatic-substituted diazene products in a one pot fashion provide a direct entry to valuable azoxy compounds and α-hydroxy-β-amino esters.

Published
2017

23. Organocatalytic Allylic Amination of Morita-Baylis-Hillman Carbonates.

Author

Formánek, Bedřich, Šimek, Michal, Kamlar, Martin, Císařová, Ivana, and Veselý, Jan

Subjects
*ORGANOCATALYSIS, *CHIRALITY, *CRYSTALLIZATION, *AMINES, *CARBONATES
Abstract

An organocatalytic asymmetric allylic amination of Morita- Baylis-Hillman carbonates with aromatic amines in the presence of ß- isocupreidine is described. Chiral allylic amines were obtained in almost quantitative yields (90-96%) with moderate enantioselectivity. Recrystallization afforded products in good yields (45-73%) and high optical purity (82-99% ee). This method provides a facile and efficient route to obtain optically active ß-lactams, including the building block of the cholesterol-lowering drug Ezetimibe. [ABSTRACT FROM AUTHOR]

Published
2019
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25. Gabriel Max's work and its reception by the Prague critics of the time

Author

Šimek, Michal, Prahl, Roman, and Musil, Roman

Abstract

Gabriel Max belongs to the exceptional personalities of the Midle European art scene of the 2nd half of the 19th century. The attention dedicated to the work of Max - Prague countryman - was enourmous. The aim of this work is the catalogization and detailed processing of the large text and picture material about Gabriel Max and his work, recorded in Prague press of the time.

Published
2012

26. Enantioselective amination pyrazolon derivatives

Author

Šimek, Michal, Veselý, Jan, and Machara, Aleš

Subjects
asymmetric synthesis,diisopropylazo-dicarboxylate,cyclisation, enantioselective, chinin, quinine, pyrazol-5-on, cinchona alkaloids, organocatalysis, enantioselektivní, amination, asymetrická syntéza, diisopropylazo-dikarboxylát,cyklizace, cinchonové alkaloidy, organokatalýza, pyrazol-5-one, aminace
Published
2012

27. Stepper motor control

Author

ŠIMEK, Michal

Abstract

The task of this Bachelor thesis was to design and assemble a testing device which will mechanically strain resistive tracks of potentiometers and trimmers. Device is assembled with a stepper controlled by ?microcontroller? PIC. Thesis contains introduction to theory of stepper motors sphere and ways of their controlling.

Published
2011

30. Gabriel Max and Prague

Author

Šimek, Michal, Petrasová, Taťána, and Prahl, Roman

Abstract

The artistic legacy of Gabriel Max left a very significant print not just in the Czech fine art of the last quarter of the 19th century but also in the Czech contemporary art critics. On the bases of the compiled catalogue of the texts about Gabriel Max and his paintings this work tries to recover the relationship between the artist and his native town.

Published
2009

32. System analysis of chosen agricultural farm at higher location at orientation on bioenergy production

Author

ŠIMEK, Michal

Subjects
zemědělská soustava, metoda uhlíkové bilance, agricultural system, bioenergie, bioenergy, carbon balance method
Abstract

Chosen agricultural enterprise Agricultural Cooperative Slapy u Tábora farms in the South Bohemia Region near the Tábor city. Analysis of inner structure of this farm was worked out for the period 1996 {--} 2006. Harvest area and yield of individual crops, mineral fertilizer consumption and cattle stock have been used for the analysis. On the basis of performed analysis, variants of inner structure have been calculated, aimed on production of bioenergy: cereals for bioethanol production, raps for biodiesel production, biogas. From aspect of energetic gain, the variant for bioethanol production was evaluated as optimal.

Published
2008

34. Establishment of Methods, Principles and Means of Coordination Abilities Development in Children

Author

Šimek, Michal, Perič, Tomáš, and Suchý, Jiří

Abstract

Název: Stanovení metod, zásad a prostředků rozvoJe koordinačních schopností dětí Setting of methods, principles and means for the development ofthe coordinative abilities of children Cíl práce: Cílem práce je na základě prostudování dostupných materiálů stanovit metody, zásady a prostředky vhodné pro účinný rozvoj koordinačních schopností dětí mladšího školního věku. Metody: Ke kompilaci a následné rewiev dostupných poznatků z oblasti koordinačních schopností byly použity kvalitativní metody sběru, analýzy a syntézy získaných poznatků. Výsledky: Poznatky získané a shrnuté v práci byl měli přispět k objasnění problematiky účinného rozvoje dětí mladšího školního věku. Klíčová slova: koordinace, věk, vývoj, zákonitosti, děti, pohybové schopnosti, rozvoj

Published
2006

35. Možnosti rozvoje turistické destinace Vysočina

Author

Becková, Helena, Šimek, Michal, Rajdl, Petr, Becková, Helena, Šimek, Michal, and Rajdl, Petr

Abstract

Diplomová práce se zaměřuje na možnosti rozvoje cestovního ruchu v regionu Vysočina. Práce vychází z charakteristiky daného kraje, jeho atraktivit pro cestovní ruch. Dále analyzuje současný stav cestovního ruchu v kraji a materiálně-technickou základnu cestovního ruchu. Výsledkem práce je vytvoření turistických produktů pro návštěvníky Vysočiny., The thesis is focused on possibilities of tourism development in the region of Vysočina. It stems from the features of this region and its attractions for tourism. It also analyzes the current state of tourism in the region and the material-technical base of tourism. The goal of the thesis is the creation of tourism products for visitors of Vysočina., Katedra dopravního managementu, marketingu a logistiky, Problematiku řešenou ve svém diplomovém projektu dokázal diplomant odpovídajícím způsobem obhájit. Prokázal schopnost samostatné práce. Odpovědi na připomínky recenzenta měl velmi dobře připraveny. Na doplňkové otázky reagoval velmi pohotově, se znalostí věci a bez závažných nepřesností je zodpověděl., Dokončená práce s úspěšnou obhajobou

Published
2010

38. Státní služba

Author

Pomahač, Richard, Šimek, Michal, Pomahač, Richard, and Šimek, Michal

Abstract

Autor se v práci zabývá problematikou státní služby v její specifické části - služebním poměru příslušníků ozbrojených sborů., Dokončená práce s úspěšnou obhajobou

Published
2007

39. Problémy majetkového vypořádání silničních pozemků

Author

Drahotský, Ivo, Šimek, Michal, Rádková, Ludmila, Drahotský, Ivo, Šimek, Michal, and Rádková, Ludmila

Abstract

Bakalářská práce se zabývá vývojem správy a údržby silnic v ČR od doby vlády Karla IV.. Práce je zaměřena na současný stav Správy a údržby silnic Pardubického kraje, popisuje její organizační uspořádání, současnou činnost i budoucí záměry Pardubického kraje, které se týkají silnic II. a III. tříd. V bakalářské práci je navrženo řešení majetkově nevypořádaných silničních pozemků v Pardubickém kraji se zaměřením na okres Svitavy. Po vyhledání pozemků v katastrálních mapách v jednotlivých katastrálních územích je zjištěna jejich výměra a množství finančních prostředků, které je zapotřebí na provedení majetkoprávního vypořádání. V případě provádění modernizace jakékoliv silnice II. nebo III. třídy v okrese Svitavy, kde nejsou všechny pozemky majetkově dořešené, mohou nastat problémy při vyřizování stavebních povolení potřebných k provádění nejrůznějších činností., Katedra dopravního managementu, marketingu a logistiky, Dokončená práce s úspěšnou obhajobou

Published
2007

40. Image turistické destinace Vysočina

Author

Becková, Helena, Šimek, Michal, Rajdl, Petr, Becková, Helena, Šimek, Michal, and Rajdl, Petr

Abstract

Práce se zabývá image turistické destinace Vysočina, vychází z jeho charakteristiky, jeho atraktivit pro cestovní ruch. Součástí práce je též analýza materiálně-technické základny (ubytovací a stravovací služby, dopravní dostupnost, apod.). Část práce tvoří vlastní výzkum, který se snaží s ohledem na spokojenost návštěvníka charakterizovat silené a slabé stránky tohoto regionu. Následně jsou pak předloženy návrhy na zlepšení image turistické destinace Vysočina., Katedra dopravního managementu, marketingu a logistiky, Dokončená práce s úspěšnou obhajobou

Published
2007

41. Korupce ve státní správě - u Policie ČR

Author

Šimek, Tomáš, Šimek, Michal, Šimek, Tomáš, and Šimek, Michal

Abstract

V diplomové práci je zachycen pohled na korupci ve státní správě a u příslušníků policie a v praktické části jejich reakce na různě závažné modelové situace. Obecná část je zaměřena na vysvětlení základních pojmů, jako je státní správa, její členění a popis jednotlivých orgánů státní správy. Dále korupce jako pojem, její příčiny a dopady. V další části popisuje korupci u policie, postih korupčního chování v trestním zákoně, které je doplněno tabulkami obsahujícími počet zjištěných a objasněných trestných činů podle jednotlivých paragrafů z posledních let. Praktická část je zaměřena na vlastní vyhodnocení dotazníků na třech různých útvarech Policie ČR a to na Inspekci ministra vnitra, Útvaru zvláštních činností a Okresním ředitelství SKPV Nymburk.V závěru je popsán současný model kontroly policie v podmínkách ČR a nastíněny jiné, odlišné modely kontroly z jiných států., The thesis focuses on corruption in state service generally and in police forces especially. In practical part is mentioned different policemen behavior in more or less serious corruption situations. General part explains basic terms like state service and its components. Then is explained corruption as a phenomenon, its reasons and entailments. Practical part is dedicated to data evaluation of question forms of three police authorities: Supervision of Department of Interior, Section of special Operations, Criminal Police Force of precinct Nymburk. At the conclusion is described police control model in the Czech republic and different models in other countries., Ústav veřejné správy a práva, Dokončená práce s úspěšnou obhajobou

Published
2007

42. Salt-kneading: alternative sizing of active pharmaceutical ingredients?

Author

Šimek, Michal, Vyňuchal, Jan, and Tomášová, Lea

Subjects
DRUG formularies, SALTS, EMULSIONS (Pharmacy), PARTICLE size determination, AGGLOMERATION (Materials)
Abstract

The most of currently produced active pharmaceutical ingredients (APIs) are poorly soluble in the human body. One of the options how to increase their dissolution rate is reducing their particle size. If very small particles of API are desired, traditional milling methods often cause smeared, agglomerated or non-flowing particles due to the forces applied. We tried to compare some of milling methods with the salt-kneading method, which is not typically used in the pharmaceutical industry. Salt-kneading process is driven by several variable parameters (e.g. the amount, hardness and particle size of the salt-kneading material), which influence the degree of size reduction of API particles which are chafed by a surplus of salt-kneading material. A model poorly-soluble API was separately processed with oscillation mill, vibratory mill and kneader; and the morphology, size distribution and solid form of prepared particles were analyzed. Our basic variation of salt-kneading parameters showed the potential of the salt-kneading method, which appears a very effective method of API controlled reduction. The final size can be modified according to the amount and properties of the salt-kneading material. The availability of such a method equips pharmaceutical scientists with a size-reduction method that provides very small, rounded and free-flowing particles of the poorly soluble API and reduces non-preferred needle shape. [ABSTRACT FROM PUBLISHER]

Published
2016
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43. Hot-stage microscopy for determination of API fragmentation: comparison with other methods.

Author

Šimek, Michal, Grünwaldová, Veronika, and Kratochvíl, Bohumil

Subjects
MICROMETRY, MEASUREMENT, MICROMETERS, MICROSCOPY, MICRO-optics
Abstract

Although the fragmentation of the active pharmaceutical ingredient (API) is a phenomenon that is mentioned in many literature sources, no well-suited analytical tools for its investigation are currently known. We used the hot-stage microscopy method, already presented in our previous work, and studied the real fragmentation of the tadalafil particles in model tablets which were prepared under different compaction pressures. The morphology, spectral imaging and evaluation of plastic and elastic energies were also analyzed to support the hot-stage method. The prepared blend of tadalafil and excipients was compacted under a several forces from 5 to 35 kN to reveal the trend of fragmentation. The exact fragmentation of tadalafil with increased compaction pressure was revealed by the hot-stage microscopic method and it was in good agreement with plastic and elastic energies. Conversely, spectral imaging, which is being used for this analysis, was considered to be inaccurate methodology as mainly agglomerates, not individual particles, were measured. The availability of the hot-stage microscopic method equips pharmaceutical scientists with anin vitroassessment technique that will more reliably determine the fragmentation of the API in finished tablets and the behavior of the particles when compacted. [ABSTRACT FROM AUTHOR]

Published
2016
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45. A new way of solid dosage form samples preparation for SEM and FTIR using microtome.

Author

Šimek, Michal, Grünwaldová, Veronika, and Kratochvíl, Bohumil

Subjects
SOLID dosage forms, SCANNING electron microscopy, FOURIER transform infrared spectroscopy, MICROTOMES, DRUG tablets
Abstract

Rapid and correct production of generic solid dosage forms requires a large amount of analytical data and conclusions. Modern analytical techniques have a good resolution and accuracy and allow obtaining a lot of information about the original product. Scanning electron microscopy (SEM) is used for observation and assessing individual layers, core and surface of solid dosage forms. Fourier transform infrared (FTIR) spectroscopy mapping allows determining the distribution and characterization of individual components in a solid dosage form. However, the samples prepared by common way, using scalpel or tablet splitter, are not good enough. It was the reason for development of a new and better method of sample preparation, which uses microtome. Well-prepared samples analyzed by SEM and FTIR mapping allow to determine a solid dosage form formulation, excipient content and distribution of excipient and active pharmaceutical ingredient. [ABSTRACT FROM AUTHOR]

Published
2014
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46. Měřicí audio předzesilovač pro komunikátor

Author

Hanák, Pavel, Balík, Miroslav, Šimek, Michal, Hanák, Pavel, Balík, Miroslav, and Šimek, Michal

Abstract

Bakalářská práce řeší mikrofonní a sluchátkový předzesilovač pro mikrotelefon a náhlavní sadu. Návrh musí splňovat požadavky na elektrické rozhraní stanovené v doporučení ITU-T Rec. P.381(08/2012). Součástí návrhu je napěťový měnič, předpětí pro mikrotelefon a napájení (z baterie i z externího zdroje). V rámci práce je také popsán návrh plošného spoje a řešení nízkého šumu v celém obvodu. Cílem práce je navrhnout, sestrojit a následně zasadit laboratorní přípravek do kovové krabičky. Nakonec přípravek změřit na analyzátoru audio precision APx525., This thesis deals with microphone and headphone preamplifier for microtelephone and headset. The design shall meet the electrical interface requirements set out in ITU-T Rec. P.381(08/2012). The design includes a voltage converter, microtelephone bias and both a battery and an external power supply. In this work is also described the design of printed circuit board and the solution of a low noise in the whole circuit. The aim of this thesis is to design, built and embed the laboratory fixture into a metal box. Finally, measure the product on an APx525 audio precision analyzer.

47. Měřicí audio předzesilovač pro komunikátor

Author

Hanák, Pavel, Balík, Miroslav, Šimek, Michal, Hanák, Pavel, Balík, Miroslav, and Šimek, Michal

Abstract

Bakalářská práce řeší mikrofonní a sluchátkový předzesilovač pro mikrotelefon a náhlavní sadu. Návrh musí splňovat požadavky na elektrické rozhraní stanovené v doporučení ITU-T Rec. P.381(08/2012). Součástí návrhu je napěťový měnič, předpětí pro mikrotelefon a napájení (z baterie i z externího zdroje). V rámci práce je také popsán návrh plošného spoje a řešení nízkého šumu v celém obvodu. Cílem práce je navrhnout, sestrojit a následně zasadit laboratorní přípravek do kovové krabičky. Nakonec přípravek změřit na analyzátoru audio precision APx525., This thesis deals with microphone and headphone preamplifier for microtelephone and headset. The design shall meet the electrical interface requirements set out in ITU-T Rec. P.381(08/2012). The design includes a voltage converter, microtelephone bias and both a battery and an external power supply. In this work is also described the design of printed circuit board and the solution of a low noise in the whole circuit. The aim of this thesis is to design, built and embed the laboratory fixture into a metal box. Finally, measure the product on an APx525 audio precision analyzer.

48. Měřicí audio předzesilovač pro komunikátor

Author

Hanák, Pavel, Balík, Miroslav, Šimek, Michal, Hanák, Pavel, Balík, Miroslav, and Šimek, Michal

Abstract

Bakalářská práce řeší mikrofonní a sluchátkový předzesilovač pro mikrotelefon a náhlavní sadu. Návrh musí splňovat požadavky na elektrické rozhraní stanovené v doporučení ITU-T Rec. P.381(08/2012). Součástí návrhu je napěťový měnič, předpětí pro mikrotelefon a napájení (z baterie i z externího zdroje). V rámci práce je také popsán návrh plošného spoje a řešení nízkého šumu v celém obvodu. Cílem práce je navrhnout, sestrojit a následně zasadit laboratorní přípravek do kovové krabičky. Nakonec přípravek změřit na analyzátoru audio precision APx525., This thesis deals with microphone and headphone preamplifier for microtelephone and headset. The design shall meet the electrical interface requirements set out in ITU-T Rec. P.381(08/2012). The design includes a voltage converter, microtelephone bias and both a battery and an external power supply. In this work is also described the design of printed circuit board and the solution of a low noise in the whole circuit. The aim of this thesis is to design, built and embed the laboratory fixture into a metal box. Finally, measure the product on an APx525 audio precision analyzer.

49. Měřicí audio předzesilovač pro komunikátor

Author

Hanák, Pavel, Balík, Miroslav, Šimek, Michal, Hanák, Pavel, Balík, Miroslav, and Šimek, Michal

Abstract

Bakalářská práce řeší mikrofonní a sluchátkový předzesilovač pro mikrotelefon a náhlavní sadu. Návrh musí splňovat požadavky na elektrické rozhraní stanovené v doporučení ITU-T Rec. P.381(08/2012). Součástí návrhu je napěťový měnič, předpětí pro mikrotelefon a napájení (z baterie i z externího zdroje). V rámci práce je také popsán návrh plošného spoje a řešení nízkého šumu v celém obvodu. Cílem práce je navrhnout, sestrojit a následně zasadit laboratorní přípravek do kovové krabičky. Nakonec přípravek změřit na analyzátoru audio precision APx525., This thesis deals with microphone and headphone preamplifier for microtelephone and headset. The design shall meet the electrical interface requirements set out in ITU-T Rec. P.381(08/2012). The design includes a voltage converter, microtelephone bias and both a battery and an external power supply. In this work is also described the design of printed circuit board and the solution of a low noise in the whole circuit. The aim of this thesis is to design, built and embed the laboratory fixture into a metal box. Finally, measure the product on an APx525 audio precision analyzer.

50. Měřicí audio předzesilovač pro komunikátor

Author

Hanák, Pavel, Balík, Miroslav, Šimek, Michal, Hanák, Pavel, Balík, Miroslav, and Šimek, Michal

Abstract

Bakalářská práce řeší mikrofonní a sluchátkový předzesilovač pro mikrotelefon a náhlavní sadu. Návrh musí splňovat požadavky na elektrické rozhraní stanovené v doporučení ITU-T Rec. P.381(08/2012). Součástí návrhu je napěťový měnič, předpětí pro mikrotelefon a napájení (z baterie i z externího zdroje). V rámci práce je také popsán návrh plošného spoje a řešení nízkého šumu v celém obvodu. Cílem práce je navrhnout, sestrojit a následně zasadit laboratorní přípravek do kovové krabičky. Nakonec přípravek změřit na analyzátoru audio precision APx525., This thesis deals with microphone and headphone preamplifier for microtelephone and headset. The design shall meet the electrical interface requirements set out in ITU-T Rec. P.381(08/2012). The design includes a voltage converter, microtelephone bias and both a battery and an external power supply. In this work is also described the design of printed circuit board and the solution of a low noise in the whole circuit. The aim of this thesis is to design, built and embed the laboratory fixture into a metal box. Finally, measure the product on an APx525 audio precision analyzer.

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