24 research outputs found
Investigation and control of ultrashort pulse propagation in photonic crystal fibers and fiber lasers in the near infrared wawelenght region
Ultrarövid fĂ©nyimpulzusok terjedĂ©sĂ©nek vizsgĂĄlata fotonikus kristĂĄly optikai szĂĄlakban Ă©s szĂĄlerĆsĂtĆkben = Investigation of propagation of ultrashort laser pulses in photonic crystal fibers and fiber amplifiers
Megmutattuk, hogy lehetsĂ©ges 6 fs-nĂĄl rövidebb kompresszĂĄlt fĂ©nyimpulzusok elĆĂĄllĂtĂĄsa fotonikus kristĂĄly szĂĄlakban 1 nJ-nĂĄl kisebb impulzusenergiĂĄk esetĂ©ben is. SzimulĂĄciĂłs programunk segĂtsĂ©gĂ©vel szĂĄmĂtĂĄsokat vĂ©geztĂŒnk, hogy milyen impulzusparamĂ©terek (energia, impulzushossz) mellett lehetsĂ©ges az impulzusok alakhƱ ĂĄtvitele nagymagĂĄtmĂ©rĆjƱ, illetve lĂ©gmagos fotonikus kristĂĄly szerkezetƱ optikai szĂĄlakon. SzimulĂĄciĂłs eredmĂ©nyeinket mĂ©rĂ©sekkel (spektrum, autokorrelĂĄciĂłs fĂŒggvĂ©nyek) ellenĆriztĂŒk Ă©s alkalmaztuk egy Ășj tipusĂș, valĂłs idejƱ, 3D kĂ©tfoton mikroszkĂłp kisĂ©rleti pĂ©ldĂĄnyĂĄnak elkĂ©szĂtĂ©sĂ©nĂ©l. Ăreges fotonikus kristĂĄly szĂĄlakat terveztĂŒnk Ă©s alkalmaztunk Yb adadĂ©kolt szĂĄlerĆsĂtĆ csörpölt impulzusainak kompresszĂĄlĂĄsĂĄra illetve nemlineĂĄris hatĂĄsoktĂłl mentes ĂĄtvitelĂ©re. MĂłdusszinkronizĂĄlt, erĆsen csörpölt nĂ©hĂĄny pikoszekundumos impulzusokat elĆĂĄllĂtĂł, telĂtĆdĆ abszorbenssel mĂłdusszinkronizĂĄlt Yb szĂĄllĂ©zert Ă©pĂtettĂŒnk, amelynek impulzusait rĂĄcsos kompresszor segĂtsĂ©gĂ©vel 200 fs-nĂĄl rövidebbre kompresszĂĄltuk. Yb adalĂ©kolt szĂĄl Ă©s fotonikus kristĂĄly szerkezetƱ pumpa geometria alkalmazĂĄsĂĄval szĂĄlerĆsĂtĆt Ă©pĂtettĂŒnk, aminek segĂtsĂ©gĂ©vel az impulzusok energiĂĄjĂĄt 80 MHz-es ismĂ©tlĆdĂ©si frekvencia mellett az 1-10 nJ tartomĂĄnyba növeltĂŒk. | We have shown that it is possible to generate sub-6-fs pulses by compression of low energy (E<1 nJ) pulses in small core area photonic crystal fibers. We have made numerical simulations to investigate that what pulse parameters (energy, peak intensity, spectral widths) allow us to deliver femtosecond laser pulses without spectral and temporal distortion through specific large mode area (LMA) and hollow core (HC) photonic crystal fibers. The validity of our simulations was checked by corresponding measurements (spectrum, autocorrelation traces). The LMA and HC fibers were applied to build a random access 3D nonlinear microscope system. The HC fibers were designed and applied for compression and distortion free delivery of amplified pulses of a picosecond pulse Yb fiber laser/amplifier system. Mode-locked, all-normal-dispersion, all-fiber Yb laser was constructed delivering few ps long, strongly chirped pulses with specral width of ~10 nm at around 1030 nm. The output of the oscillator was compressed down to 200 fs using a grating pair compressor. Using a double clad Yb doped fiber and a photonic crystal pump geometry, the pulse energy was boosted up to the 1-10 nJ regime at a repetition rate of 80MHz
Emergence of a new salt-tolerant alien grass along roadsides? Occurrence of Diplachne fusca subsp. fascicularis (Poaceae) in Hungary
This paper reports the occurrence of a North American salt-tolerant taxon, Diplachne fusca subsp. fascicularis (Lam.) P.M.Peterson et N.Snow in Hungary (Central-Europe). Two earlier Hungarian observations of D. fusca were known from 1915, near GyĆr (West Transdanubia), later the taxon was collected by PĂ©nzes in 1958, in downtown BudatĂ©tĂ©ny (central Hungary. Both observations seem to be occasional. Recently, the taxon has started spreading in Europe, mainly on rice paddy fields, with a serious invasion potential. In North America its appearance on ruderal habitats, as well as along roads and other linear infrastructures is a well known phenomenon. The Hungarian population was found near CeglĂ©d (Central Hungary) on the roadside of the E40 primary main road in September 2018. In July 2019 more than one thousand (mostly vegetative) individuals were detected. The salt content of the habitat shows remarkable temporal and spatial variability. At one meter distance from the edge of the paved road soil salt content was higher in spring (after the winter de-icing regime), than in autumn. Salt concentration was highest in the vicinity of the road, and decreased with increasing distance from it. Germination tests revealed a significant negative effect of NaCl concentration on germination rates, but germination occurred even on extremely saline substrates with 1.5% NaCl concentration. Considering its biology and reproduction strategy, the further spread of Diplachne fusca is highly presumable
Influence of acid-induced conformational variability on protein separation in reversed phase high performance liquid chromatography
Influence of acid concentration in the mobile phase on protein separation was studied in a wide concentration range of using trifluoroacetic acid (TFA) and formic acid (FA). At low, 0.001-0.01 v/v% TFA concentration and appropriate solvent strength proteins elute before the column's dead time. This is explained by the proteins having a structured, but relatively extended conformation in the eluent; and are excluded from the pores of the stationary phase. Above ca. 0.01-0.05 v/v% TFA concentration proteins undergo further conformational change, leading to a compact, molten globule-like structure, likely stabilized by ion pairing. Proteins in this conformation enter the pores and are retained on the column. The results suggest a pore exclusion induced separation related to protein conformation. This effect is influenced by the pH and type of acid used, and is likely to involve ion-pair formation. The TFA concentration needed to result in protein folding (and therefore to observe retention on the column) depends on the protein; and therefore can be utilized to improve chromatographic performance. Conformation change was monitored by circular dichroism spectroscopy and mass spectrometry; and it was shown that not only TFA, but FA can also induce molten globule formation
OWLAP - using OLAP approach in anomaly detection
OWLAP (Operative Workbench for Large-scale Analytics and Presentation) is a visual analytics tool that allows the user to browse and drill down the multidimensional data on-line with the possibility to export result into a zooming presentation framework. We address the challenges of multidimensional visualization by aiding the cognitively hard task of understanding attributes, finding patterns and outliers. We successfully solved the challenge of real time Big Data OLAP reporting by a home developed multithreaded inmemory database manager. Our additional focus is the automatic management of summary preparation that we aid by scripting the presentation framework of Prezi Inc
Testes tĂ©mĂĄk - Az Ă©rzĂ©kszervek Ă©s az Ă©rzĂ©kelĂ©s cĂmƱ idĆszaki kiĂĄllĂtĂĄs = Bodily matters - Temporary exhibition on perception and sensory organs
Novel members of bacterial community during a short-term chilled storage of common carp (Cyprinus carpio)
Revealing a Phenotypical Appearance of Ibrutinib Resistance in Patients With Chronic Lymphocytic Leukaemia by Flow Cytometry
Background: Ibrutinib is widely known as an effective and well-tolerated therapeutical choice of the chronic lymphocytic leukaemia (CLL). However, acquired resistance may occur during the treatment, causing relapse. Early detection of ibrutinib resistance is an important issue, therefore we aimed to find phenotypic markers on CLL cells the expression of which may correlate with the appearance of ibrutinib resistance
Cryptocapsinepoxide-type Carotenoids from Red Mamey, Pouteria sapota
Three new carotenoids, cryptocapsin-5,6-epoxide, 3Êč-deoxycapsanthin-5,6-epoxide, and cryptocapsin-5,8-epoxides, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Cryptocapsin-5,6-epoxide was prepared by partial synthesis via epoxidation of cryptocapsin and the (5R,6S)- and (5S,6R)-stereoisomers were identified by HPLC-ECD analysis. Spectroscopic data of the natural (anti) and semisynthetic (syn) derivatives obtained by acid-catalyzed rearrangement of cryptocapsin-5,8-epoxide stereoisomers were compared for structural elucidation. Chiral HPLC separation of natural and semisynthetic samples of cryptocapsin-5,8-epoxides was performed and HPLC-ECD analysis allowed configurational assignment of the separated stereoisomers