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Optofluidic techniques for directed evolution of enzymes
Pilát, Zdeněk; Ježek, Jan; Samek, Ota; Zemánek, Pavel; Buryška, T.; Damborský, J.; Prokop, Z.
2018 - English
Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate\nlarge variety of reactions, while ensuring appropriate catalytic activity and high selectivity.\nThese properties make enzymes attractive biocatalysts for a wide range of industrial and\nbiomedical applications. Over the last two decades, directed evolution of enzymes has\ntransformed the field of protein engineering.
Keywords:
optofluidics; Raman spectroscopy; enzymes
Available at various institutes of the ASCR
Optofluidic techniques for directed evolution of enzymes
Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate\nlarge variety of reactions, while ensuring appropriate catalytic activity and high selectivity.\nThese ...
Real time observation of strain in the SEM sample
Piňos, Jakub; Frank, Luděk
2018 - English
The SEM with various detector arrangements and analytical attachments represents an\nirreplaceable tool in material research. One of the techniques available in most contemporary\nmicroscopes is the scanning low energy electron microscopy (SLEEM) with biased specimen, marketed as the beam deceleration mode, gentle beam and others. The SLEEM allows\ncontrolling the information depth of the backscatter electron (BSE) imaging within a wide\nrange by altering the landing energy of electrons.
Keywords:
SEM; SLEEM; deformation
Available at various institutes of the ASCR
Real time observation of strain in the SEM sample
The SEM with various detector arrangements and analytical attachments represents an\nirreplaceable tool in material research. One of the techniques available in most contemporary\nmicroscopes is the ...
Grazing incidence interferometer for form measurement of hollow cylinders
Šarbort, Martin; Řeřucha, Šimon; Holá, Miroslava; Lazar, Josef
2018 - English
Optical metrology of cylindrical specimens represents an interesting task in scientific and\nindustrial practice. The most precise measurement methods use principles of laser\ninterferometry where the phase difference between the reference wave and the object wave reflected from the tested surface is detected. The form measurement of hollow cylindrical tubes can be advantageously realized by an object wave with conical wavefronts generated by an axicon lens or an equivalent diffractive optical element. An axicon characterized by large apex angle forms a conical wave that fulfills the conditions of the grazing incidence, which results in suppression of the speckle noise. The previous experimental setups were relatively complex since they involved a pair of mutually reversed axicons or a pair of diffractive optical elements that transform the object wave from planar to conical and vice\nversa.
Keywords:
interferometry; surface metrology; hollow cylinders
Available at various institutes of the ASCR
Grazing incidence interferometer for form measurement of hollow cylinders
Optical metrology of cylindrical specimens represents an interesting task in scientific and\nindustrial practice. The most precise measurement methods use principles of laser\ninterferometry where the ...
Imaging via multimode optical fiber: recovery of a transmission matrix using internal references
Šiler, Martin; Jákl, Petr; Traegaardh, Johanna; Ježek, Jan; Uhlířová, Hana; Tučková, Tereza; Zemánek, Pavel; Čižmár, Tomáš
2018 - English
Current research of life shows a great desire to study the mechanics of biological processes\ndirectly within the complexity of living organisms. However, majority of practical techniques\nused nowadays for tissue visualization can only reach depths of a few tens of micrometres as\nthe issue obscures deep imaging due to the random light scattering. Several imaging\ntechniques deal with this problems from different angels, such as optical coherence\ntomography, light sheet microscopy or structured light illumination A different and promising strategy to overcome the turbid nature of scattering tissues is to employ multimode optical fibers (MMF) as minimally invasive light guides or endoscopes to provide optical access inside. Although the theoretical description of light propagation through such fibers has been developed a long time ago it is frequently considered inadequate to describe real MMF. The inherent randomization of light propagating through MMFs is typically attributed to undetectable deviations from the ideal fiber structure. It is a commonly believed that this\nadditional chaos is unpredictable and that its influence grows with the length of the fiber.\nDespite this, light transport through MMFs remains deterministic and can be characterized by a transmission matrix (TM) which connects the intensity and phase patterns on the fiber input and output facets. Once the TM is known it can be used to create focus in any desired 3D\ncoordinates beyond the distal fiber facet, see figure 1, and perform e.g. fluorescence based\nlaser scanning microscopy or optical trapping.
Keywords:
multimode optical fiber
Available at various institutes of the ASCR
Imaging via multimode optical fiber: recovery of a transmission matrix using internal references
Current research of life shows a great desire to study the mechanics of biological processes\ndirectly within the complexity of living organisms. However, majority of practical techniques\nused ...
Interferometrický kalibrátor pro měření vlnových délek
Jedlička, Petr; Mikel, Břetislav; Řeřucha, Šimon; Matěj, Z.; Herman, O.; Holá, Miroslava; Jelínek, Michal; Pavelka, Jan; Číp, Ondřej; Lazar, Josef
2018 - Czech
Systém je navržen pro kalibraci měřicího rámu, kterým se kontrolují rozměry reaktorové nádoby. Rám je při měření spouštěn do reaktoru a výsuvnými koncovými snímači měří jeho rozměry. Měřené hodnoty jsou až\n3300 mm. Před měřením je třeba měřicí rám jako celek kalibrovat.\n Interferometric system is designed to calibrate the measurement frame, used for periodic assessment of the inner geometry of the reactor active zone chassis. Calibration lenght is up to 3300mm.
Keywords:
laser interferometry; optical metrology; nanometrology
Available at various institutes of the ASCR
Interferometrický kalibrátor pro měření vlnových délek
Systém je navržen pro kalibraci měřicího rámu, kterým se kontrolují rozměry reaktorové nádoby. Rám je při měření spouštěn do reaktoru a výsuvnými koncovými snímači měří jeho rozměry. Měřené hodnoty ...
Přenos stabilní optické frekvence mezi pracovišti ÚPT a CESNET
Čížek, Martin; Pravdová, Lenka; Hucl, Václav; Jelínek, Michal; Hrabina, Jan; Řeřucha, Šimon; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej; Smotlacha, V.; Havliš, O.; Vojtěch, J.
2018 - Czech
Příspěvek pojednává o aktuálním stavu 306 km dlouhé experimentální linky pro přenos stabilní optické frekvence z telekomunikačního laserového normálu provozované mezi laboratořemi oddělení koherenční optiky na ÚPT AVČR v Brně a pracovištěm CESNET v Praze. Obousměrná linka využívá telekomunikační vlákno s vyhrazeným DWDM oknem 1540-1546 nm. V podmínkách ČR je v současné době uplatnění této technologie perspektivní jednak pro vzájemné porovnávání stability optických normálů a zároveň také pro dálkovou kalibraci přesných měřicích přístrojů (např. optické spektrální analyzátory) umístěných v průmyslových provozech (jaderná elektrárna), které nedovolují jejich transport do laboratoře s normálem optické frekvence. Byla vyhodnocena stabilita přenosu po kompenzované lince a provedeno dlouhodobé měření změn transportního zpoždění na lince. The contribution reports on the current state of a 306km long experimental line for transfering stable optical frequency from a telecommunication band laser standard between ISI CAS (Brno) and CESNET (Prague). The bidirectional link uses a telecommunication fiber with a dedicated DWDM window of 1540-1546 nm.1540-1546 nm. In the Czech rep. this technology can be utilized currently in two fields: remote comparisons of optical frequency standards and remote callibration of instruments (optical spectral analyzers) in industrial applications that do not allow transporting the device to a specialized laboratory. The stability of the optical frequency transfer was evaluated. A long-term measurement of transport delay was conducted. \n
Keywords:
measurement; metrology; photonic networks; time and frequency standards; optical frequency stability measurement; feedback loops
Available at various institutes of the ASCR
Přenos stabilní optické frekvence mezi pracovišti ÚPT a CESNET
Příspěvek pojednává o aktuálním stavu 306 km dlouhé experimentální linky pro přenos stabilní optické frekvence z telekomunikačního laserového normálu provozované mezi laboratořemi oddělení koherenční ...
Laserová ablace atomů vápníku pro experiment laserového chlazení atomů
Grim, Jakub; Pham, Minh Tuan; Číp, Ondřej
2018 - Czech
Naše práce popisuje dvě nejčastější metody vytváření neutrálních atomů potřebných pro experimenty se zachycenými a ochlazenými ionty. Nejsnadnější, ale nejefektivnější způsob vytváření neutrálních atomů je použití tepelné pícky. Lepší metodou umožňující jemnou kontrolu generování atomů je použití pulzní laserové ablace. Byla sestavena vakuová komora s zdrojem atomů Ca a nezbytnou optikou. Detekce generovaných částic byla dosažena laserem indukovanou fluorescenci a citlivou kamerou. Práce se skládá z měření obou metod generování atomů. Our work describes two most common methods of generating neutral atoms needed for experiments with trapped and cooled ions. The easiest but not most effective way of the neutral atoms generating is to use a heated oven. A better method allowing a fine control of generating atoms is to use a pulsed laser ablation. A vacuum chamber with Ca atoms source and necessary optics was assembled. Detection of generated particles was achieved by laser-induced fluorescence and sensitive camera. The paper consists of measurement of both method of generating the atoms.
Keywords:
pulsed laser ablation; atoms generating
Available at various institutes of the ASCR
Laserová ablace atomů vápníku pro experiment laserového chlazení atomů
Naše práce popisuje dvě nejčastější metody vytváření neutrálních atomů potřebných pro experimenty se zachycenými a ochlazenými ionty. Nejsnadnější, ale nejefektivnější způsob vytváření neutrálních ...
Výpočet průběhu potenciálů a simulace chování iontů vápníku v Paulově iontové pasti
Vadlejch, Daniel; Oral, Martin; Lešundák, Adam; Pham, Minh Tuan; Čížek, Martin; Číp, Ondřej; Slodička, L.
2018 - Czech
Přesnost experimentů prováděných zachycenými ionty uvnitř Paulovy lineární iontové pasty je velmi závislá na velikosti reziduálního pohybu iontů. Dva odlišné režimy radiofrekvenčního řízení elektrod se porovnávají s ohledem na velikost iontového mikromotoru ve směru osy pasti. Toto porovnání mikropohybu zachyceného iontu je prováděno numerickým výpočtem metodou konečných prvků pro geometrii, což odpovídá pasti umístěnému v laboratoři Ústavu vědeckých přístrojů AV ČR v Brně. Výsledky výpočtů ukazují, že symetrický režim řízení by měl být vhodnější pro oslabení axiální složky mikropohybu zachycených iontů. Precision of the experiments performed using trapped ion within Paul’s linear ion trap is highly dependent on the magnitude of ion’s residual motion. Two different radiofrequency driving modes of the electrodes are compared with respect to magnitude of the ion’s micromotion in the direction of trap’s axis. This comparison of the trapped ion’s micromotion is carried by numerical calculation using finite element method for geometry, which corresponds to trap located in laboratory of Institute of Scientific Instruments, Czech Academy of Science in Brno. The results of the calculations show that symmetrical driving mode should be more suitable to attenuation of trapped ion’s micromotion’s axial component.
Keywords:
linear ion trap; micromotion; FEM; laser spectroscopy; metrology; secular motion; secular frequency
Available at various institutes of the ASCR
Výpočet průběhu potenciálů a simulace chování iontů vápníku v Paulově iontové pasti
Přesnost experimentů prováděných zachycenými ionty uvnitř Paulovy lineární iontové pasty je velmi závislá na velikosti reziduálního pohybu iontů. Dva odlišné režimy radiofrekvenčního řízení elektrod ...
Electron beam welding at ISI Brno
Dupák, Libor; Zobač, Martin; Vlček, Ivan; Zobačová, Jitka
2018 - English
In vacuum technology, and especially in UHV, we often encounter the necessity of joining\nparts of various metals in combination with the demand for perfect vacuum tightness,\ncleanness of joints and minimum deformations. Electron beam welding belongs to the\nbest technologies capable of fulfilling such requirements.\nThe principle of electron beam welding is based on the transfer of the kinetic energy of the\nincident accelerated electrons to the welded material in the form of heat. The temperature in\nthe spot rises with the beam power density. At power densities as high as 104 - 106 W/mm2,\nthe melted material at the center of the focal point evaporates. This produces a vapor capillary surrounded by melted material that allows the beam to penetrate deeper and melt more material. The speed of the penetration can be much higher than the heat transfer by\nconduction into the surrounding material. This results in narrow melted area and typical knifelike\nprofile of the weld. Thanks to this effect the thermal deformations of welded\npieces are highly reduced to almost none. Small heat affected zone also allows welding near\nheat sensitive parts like sensors, ceramic feed-throughs and brazed joints.
Keywords:
electron beam welding
Available at various institutes of the ASCR
Electron beam welding at ISI Brno
In vacuum technology, and especially in UHV, we often encounter the necessity of joining\nparts of various metals in combination with the demand for perfect vacuum tightness,\ncleanness of joints and ...
Possibilites of a secondary electrons bandpass filter for standard SEM
Mika, Filip; Pokorná, Zuzana; Konvalina, Ivo; Khursheed, A.
2018 - English
Secondary electron filtering in Scanning Electron Microscope (SEM) has been in use for over\na decade. This technique uncovers interesting contrasts in an otherwise ordinary SEM image\nwhich can possibly be used for dopant concentration mapping or for discerning the slight molecular weight differences in apparently homogeneous organic materials. Secondary\nelectron filtering of semiconductor samples seems very promising as it may shed light on the mechanism of SEM image contrast between p-doped and n-doped semiconductors, possibly\nallowing to determine dopant concentration from SEM image alone.
Keywords:
secondary electron; filtering; imaging
Available at various institutes of the ASCR
Possibilites of a secondary electrons bandpass filter for standard SEM
Secondary electron filtering in Scanning Electron Microscope (SEM) has been in use for over\na decade. This technique uncovers interesting contrasts in an otherwise ordinary SEM image\nwhich can ...
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