Limited validity of West and Yennie integral formula for elastic scattering of hadrons

The commonly used West and Yennie integral formula for the relative phase between the Coulomb and elastic hadronic amplitudes might be consistently applied to only if the hadronic amplitude had the constant ratio of the real to the imaginary parts al all kinematically allowed values of four momentum transfer squared.Comment: 5 page

Interference between Coulomb and hadronic scattering in elastic high-energy nucleon collisions

The different models of elastic nucleon scattering amplitude will be discussed. Especially, the preference of the more general approach based on eikonal model will be summarized in comparison with the West and Yennie amplitude that played an important role in analyzing corresponding experimental data in the past.Comment: 13 pages, 2 figure

Corrosion of Metals in Chlorides According to Global Harmonized System

Přepravou chemických látek a směsí často dochází ke koroznímu napadení jejich ochranných obalů, jeţ můţe vést aţ k únikům přepravovaných chemikálií do okolí. Tato práce se zabývá korozními účinky roztoku obsahujícího destilovanou vodu s 5 hm. % NaCl a dále roztoku obsahujícího destilovanou vodu s 2,5 hm. % NaCl a 2,5 hm. % močoviny. Těmto korozním prostředím byly vystaveny vzorky z hliníku o čistotě 99,5 % a nelegované konstrukční oceli 11 373 (EN 10131). Na základě provedených korozních zkoušek byly vyhodnoceny hmotnostní úbytky, rychlosti koroze, metalografické vyhodnocení a porovnání výsledků s kritérii uvedenými v metodice OECD, která je uváděna systémem GHS.Transportation of chemicals and mixtures often leads to corrosive damage to their protective packaging, which could cause leakage of transported chemicals to the surroundings. This thesis deals with the corrosive effects of a solution which contains distilled water with 5 wt. % of NaCl solution and distilled water containing 2.5 wt. % of NaCl and 2.5 wt. % of urea. Samples of aluminium with purity of 99.5 % and non-alloy steel EN 10131 were exposed to these corrosive environments. Based on the performed corrosion tests were evaluated weight losses, the speed of corrosion, metallographic evaluation and comparison of results with the criteria according to the OECD methodology, which is indicated by GHS.

PREPARATION AND CHARACTERIZATION OF BIOPOLYMER-BASED NANOPARTICLES AND NANOFIBERS AND THEIR APPLICATION IN FOOD AND COSMETICS

Předložená disertační práce se zabývá polymerem polyhydroxybutyrátem a dalšími biopolymery jakožto základním stavebním kamenem pro výstavbu mikro a nanoskopických struktur a materiálů použitelných v potravinářství a kosmetice. V rámci práce byla vypracována literární rešerše seznamující čtenáře se základy tohoto aplikačního pole. Experimentální část práce je sestavena ze tří bloků výsledků získaných během doktorského studia. V prvním, hlavním bloku jsou uvedeny komentované publikované výsledky a patentové výstupy, které zahrnují dva publikované recenzované články zabývající se elektrostatickým a mokrým zvlákněním PHB a vlastnostmi připravených materiálů. Patentové výstupy jsou tvořeny několika přijatými a podanými patenty, které shrnují několikaletou práci jednak na metodách zvláknění PHB, ale taktéž na obecných přístupech umožňující zpracovávat PHB v podobě roztoku do podob umožňujících mnohé aplikace v potravinářství a kosmetice. Druhá část je tvořena jedním z praktických výstupů, jímž je patentovaná kompozice ochranného krému proti UV záření založena na připravených nanoskopických a mikroskopických morfologiích PHB. Ve třetím bloku jsou shrnuty další výsledky zaměřené na elektrostatické zvláknění PHB a dalších biopolymerů. V závěru práce je uveden stručný popis projektů souvisejících s tématem disertační práce. Jde o praktické rozvojové práce ve střední Tanzánii a západní Africe, které ale čerpají z vědomostí a kontaktů nabytých během studia na FCH VUT Brno.The presented dissertation thesis deals with the polymer polyhydroxybutyrate and other biopolymers as a basic building block for the construction of micro- and nanoscopic structures and materials used in food and cosmetics. In the theoretical part, current literary review is prepared to introduce the basics of this application field. The practical part of the work is composed of three blocks developed during the doctoral study. In the first and most important part are summarized comments to the academic and patent outputs, where among the academic ones it is possible to find two peer-reviewed articles dealing with the electrostatic and wet spinning of PHB and properties of prepared materials. The patent outputs consist of several accepted and applied projects, which summarize results on both PHB spinning methods, but also on general approaches enabling the processing of PHB into forms enabling many applications in food and cosmetics. Second part was focused on the patented composition of the UV protection cream based on the prepared nanoscopic and micro- morphologies of PHB. The third block summarizes results focused predominantly on the electrostatic spinning of PHB and other biopolymers. Finally, a short chapter containing a brief description of projects that were in a way related to the dissertation topic, but rather practical development work in Central Tanzania and West Africa, which draw on knowledge and contacts gained during studies at FCH BUT Brno.

Hydrogen-terminated detonation nanodiamond:impedance spectroscopy and thermal stability studies

In this paper, we investigated the effect of hydrogen termination on the electrical properties and impedance spectra of detonation nanodiamond. The impedance spectra revealed that the hydrogen-termination process increases the electrical conductivity by four orders of magnitude at room temperature. An equivalent circuit has been proposed to correlate with the conduction mechanism. Arrhenius plot showed that there were two different activation energy levels located at 0.089 eV and 0.63 eV between 50 °C and 400 °C. The possible physical mechanism corresponding to these activation energy levels has been discussed. Hydrogen-terminated detonation nanodiamond has been further annealed at different temperatures prior to FTIR and XPS measurements in order to understand their thermal stability. The results demonstrated that the surface oxidization occurred between 100 °C and 150 °C. However, the C-H bonds could partially survive when the temperature reaches 400 °C in air

Carbon nanowalls grown by microwave plasma enhanced chemical vapor deposition during the carbonization of polyacrylonitrile fibers

We used microwave plasma enhanced chemical vapor deposition (MPECVD) to carbonize an electrospun polyacrylonitrile (PAN) precursor to form carbon fibers. Scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the fibers at different evolution stages. It was found that MPECVD-carbonized PAN fibers do not exhibit any significant change in the fiber diameter, whilst conventionally carbonized PAN fibers show a 33% reduction in the fiber diameter. An additional coating of carbon nanowalls (CNWs) was formed on the surface of the carbonized PAN fibers during the MPECVD process without the assistance of any metallic catalysts. The result presented here may have a potential to develop a novel, economical, and straightforward approach towards the mass production of carbon fibrous materials containing CNWs

Software-Defined Optics in Last Mile for Research and Education in the Czech Republic

The Software Defined Networking (SDN) gained recognition due to its improvements at the packet switching and routing layers. The benefits of programmable, remotely controllable networking devices can be applied to the optical layer of contemporary networks as well. This work introduces CESNET's Czech Light~® family of devices and their role in enabling the SDN approach within the CESNET's production network. As a case study, an upgrade of the Cheb node in CESNET's network from a hard-spliced add-drop multiplexers to SDN-capable Reconfigurable Optical Add-Drop Multiplexers (ROADM) is presented. The upgrade improved operational capabilities of the network, including remote channel equalization, and the possibility to deploy new channels or lambdas without physical intervention. The deployment of ROADM also improved the optical properties of the network

Generation of a Conjoint Surface Plasmon by an Infrared Nano‐antenna Array

Localized surface plasmons (LSP) excited by optical fields have many potential applications resulting from their ability in detecting ultra‐small, ambient refractive index change. Current methods using surface nano‐patterning by means of lithography have given rise to LSP of limited propagation and interaction lengths, meaning that practical applications remain challenging. This paper describes a new all‐optical method of generating LSP by means of a carefully fabricated low dimensional nano‐structured material by using a direct‐write photochemical lithography. It is shown that the resulting array of localized surface plasmons combine or “Conjoin” to have an unprecedented large interaction length, via coupled evanescent fields, giving rise to superior spectral sensitivities; several orders of magnitude better than those quoted elsewhere and reaching 6×103 nm/RIU in the aqueous regime and 104 nm/RIU in the gaseous regime. Numerical modeling was performed that showed this design of plasmonic platform is capable of producing sensitivities of 105‐106 nm/RIU. We believe the results achieved in this investigation show that a unique conjoint surface plasmon operational mode will significantly impact areas of interest, such as single molecular dynamics, drug delivery systems etc