RAMAN SPECTROSCOPY STRUCTURAL STUDY OF FIRED CONCRETE

Raman spectroscopic structural analysis of concrete cementious matrix represents elegant method to determination of thermal history of highly exposed concrete. Experiments were carried out in furnace at 1200°C. On the surface of heated concrete mechanical cracks and the mixture of dicalcium silicate and gehlenite were found, while inside the cracks the development of gehlenite, pseudowollastonite, pseudobrookite and various iron oxides and spinels was observed. The products of chemical reactions analyzed by Raman spectroscopy can be used as markers for the identification and understanding the structural changes during a fire treatment

Optical Properties of Erbium and Erbium/Ytterbium Doped Polymethylmethacrylate

In this paper we report on the fabrication and properties of Er3 and Er3/Yb3 doped Polymethylmethacrylate (PMMA) layers. The reported layers were fabricated by spin coating on silicon or on quartz substrates. Infrared spectroscopy was used for an investigation of O-H stretching vibration. Measurement were made of the transmission spectra in the wavelength ranges from 350 to 700 nm for the Er3 doped samples and from 900 to 1040 nm for the Yb3 doped samples. The refractive indices were investigated in the spectral range from 300 to 1100 nm using optical ellipsometry and the photoluminescence spectra were measured in the infrared region

Reimbursement of the legal representation in civil proceedings with special focus on petty legal disputes

Reimbursement of the legal representation in civil proceedings with special focus on petty legal disputes This thesis concerns with a development and current legislation and case law of the higher courts in cases of granting compensation for legal representation in court proceedings. After a brief historical excursion is described current legislation of the negotiation and providing a fee for legal services of attorney. Given the fact that's attorney's remuneration is granted as a part of the costs of proceedings, this thesis describes general rules for granting mentioned costs with a special focus on reimbursement of representation, in particular is discussed in terms of the effectiveness of legal representation. In the following, the largest part of the thesis issues recent development of costs of proceedings in "petty disputes" including a judicature of Supreme Court and Constitutional Court in a variety of situations. Described section of thesis briefly but comprehensively presents attitudes and intellectual trends of courts and legislators in concerned area. The thesis subjected the current legislation and case law to a criticism, and found out that in some cases is judicature and legislation in contrast of basic law principles and equity principle. The other two sections of thesis are mainly..

Testing of the differential protection relays by the tester CMC256+

The bachelor`s thesis is focused on the concepting of tests and measurements for the differential protection relays by the tester CMC 256+. At the beginning of the document are elaborated theoretical knowledges of electrical wiring failures and their consequences, which differential protection relays help to prevent. Furthermore, the description of the function of differential protection relays and their splitting by way of comparison and protecting criteria. Theoretical analysis of differential protection relays testing includes a brief description of measurements carried out by conventional laboratory techniques and a detailed description of the measuring by tester CMC 256 + along with an explanation of its functions. The thesis include a description of functions and parameters measured by differential protection relay S-30 of the ZPA Trutnov company. This work is accompanied by a laboratory task concept focusing on comparative tests of S-30 along with a description of the measuring procedure by using CMC 256+. The concept of tasks is based on the options that are available by using the basic operating software Protection package and the acomplished measurements

Structural characterization of PET fiber-reinforced cement-based composite

The Raman microspectroscopy mapping technique, nanoindentation and environmental scanning electron microscopy (ESEM) in combination with microanalysis (EDX), and electron diffraction (EBSD-OIM)were successfully used to study of the interfacial transition zone (ITZ) around polyethylene terephtalate (PET) reinforcement in concrete

PET fiber-reinforced cement-based composite

Ageing of poly(ethylene terephthalate) fibers in cement based composite in on mechanical properties of the composite has been studied

Development and role of the 4PL concept in global trade

Cílem práce je prostřednictvím dotazníkového šetření a rozhovoru s vybranými odborníky z oblasti logistiky zjistit aktuální stav poznání a vyžívání modelu 4PL mezi vybranými společnostmi působícími v České republice. Ačkoliv je tento model známý již od konce minulého století, jeho pravý potenciál se objevuje v posledních několika letech s rostoucí mírou globalizace. Tradičnější modely řízení dodavatelského řetězce, jako například in-house nebo 2PL, nejsou mnohdy schopny takové míry flexibility a odolnosti vůči narušením jako model 4PL. Nadřazenost tohoto modelu se ukázala především v době pandemie covid-19. Zatímco jiné dodavatelské řetězce kolabovaly, dodavatelské řetězce řízené v modelu 4PL byly schopny této krizi odolat jen s malými výpadky. Teoretická část práce je zaměřena na vznik modelu 4PL, definici jednotlivých modelů řízení dodavatelských řetězců, důvody pro outsourcing řízení dodavatelského řetězce, jednotlivé prvky řešení modelu 4PL, přidanou hodnotu modelu 4PL, identifikaci současných nároků a problematických oblastí v dodavatelském řetězci a představení nejvýznamnějších poskytovatelů 4PL logistiky v České republice. V praktické části práce jsou vyhodnoceny výsledky dotazníkového šetření doplněné o poznatky získané rozhovorem s vybranými odborníky z oblasti logistiky.The goal of this bachelor thesis is to determine through a questionnaire survey and interview with selected experts in the field of logistics the current state of knowledge and implementation of the 4PL concept among selected companies operating in the Czech Republic. Although this concept has been known since the end of the last century, its true potential is only showing in the last few years with the rising degree of globalization. More traditional models of supply chain management, like in-house or 2PL, are often incapable of the same level of flexibility and resilience to disruptions as the 4PL model. Superiority of this model is apparent especially in the time of covid-19 pandemic. While other supply chains collapsed, supply chains managed in 4PL concept were able to withstand this crisis with only minor interruptions. Theoretical part of this thesis is focused on the origin of the 4PL concept, definition of different supply chain management models, reasons to outsource supply chain management, aspects of the 4PL concept, value added of the 4PL concept, main supply chain requirements and Pain Points, and presentation of the most significant 4PL providers in Czech Republic. The practical part of the work evaluates the results of a questionnaire survey supplemented by knowledge gained from interviews with selected experts in the field of logistics

Preparation of calibration gauges for eddy current testing method

Cieľom diplomovej práce je objasniť tému kalibračných mierok používaných pri skúšaní vírivými prúdmi na zariadeniach v jadrovej energetike. Teoretická časť diplomovej práce je zameraná na metódu skúšania vírivými prúdmi, ktorá sa radí do technológie nedeštruktívnej defektoskopie. Táto časť práce popisuje princíp metódy jej rozsah, obmedzenia a rozdelenie snímačov používaných pri tejto metóde skúšania. Práca v krátkosti popisuje fyzikálny princíp lasera, jeho druhy a pracovné režimy. Praktická časť práce je zameraná na výrobu kalibračnej mierky laserom. Ďalším bodom práce je porovnanie údajov získaných z merania metódou vírivých prúdov na mierkach vyrobených laserom a na kalibračných mierkach používaných v praxi.The aim of the diploma thesis is to clarify the topic of calibration samples used in eddy current testing on equipment in nuclear energy. The theoretical part of the diploma thesis is focused on the eddy current testing method, which belongs to the technology of non-destructive defectoscopy. This part of the work describes the principle of the method, its scope, limitations and dividing of sensors used in this test method. The work briefly describes the physical principle of the laser, its types and operating modes. The practical part of the work is focused on the production of a calibration samples by laser. Another point of the work is the comparison of data obtained from eddy current measurements on samples made by laser and on calibration samples used in practice.

Adsorption of zinc and copper ions on natural and ethylenediamine modified montmorillonite

In this study, adsorption of the zinc and copper ions on montmorillonite (MMT) was investigated. In all experiments performed at pH 6.4 to 4.8, the Langmuir-Freundlich isotherm was found to best fit adsorption data that confirms a monolayer formation of the metals. The maximum amounts of the adsorbed metals did not exceed a cation exchange capacity (CEC) of MMT. UV-VIS diffuse reflectance spectrometry reveals no complexes between Zn2+ or Cu2+ and MMT and thus the metal uptake took part only by ion exchange. X-ray diffraction (XRD) patterns indicated an intercalation of the metal ions into the montmorillonite interlayer. In addition, using thermogravimetry and infrared spectrometry it was found the intercalated metals create aqua complexes [Zn(H2O)6]2+ and [Cu(H2O)6]2+. In order to increase the adsorbed amounts of Zn2+ and Cu2+, MMT was previously intercalated with ethylenediamine (EDA-MMT). EDA caused an increase of the adsorbed copper ions about 28 % due to the formation [Cu(EDA)2]2+ in the interlayer as was confirmed by the infrared spectrometry. Adsorbed amounts of the zinc ions on EDA-MMT was 3-4 folds higher than CEC but no complex with EDA was observed. This effect was explained by expansion of a space between the montmorillonite layers, which facilitates the intercalation of the zinc ions and nitrate compensating the excessive positive charge