A monolithic resonant terahertz sensor element comprising a metamaterial absorber and micro-bolometer

In this article a monolithic resonant terahertz sensor element with a noise equivalent power superior to that of typical commercial room temperature single pixel terahertz detectors and capable of close to real time read-out rates is presented. The detector is constructed via the integration of a metamaterial absorber and a micro-bolometer sensor. An absorption magnitude of 57% at 2.5 THz, a minimum NEP of inline image and a thermal time constant of 68 ms for the sensor are measured. As a demonstration of detector capability, it is employed in a practical Nipkow terahertz imaging system. The monolithic resonant terahertz detector is readily scaled to focal plane array formats by adding standard read-out and addressing circuitry enabling compact, low-cost terahertz imaging

Finansinės nuomos ir tiesioginio lizingo santykis pagal Lietuvos Respublikos civilinį kodeksą.

After restoring restauration of the independence of the Republic of Lithuania on 11 March 1990, the market economy in Lithuania started to develop rather rapidly. However, for more than a decade the contractual relations of financial leasing were not regulated by special legal provisions. And only when the new Civil Code of the Republic of Lithuania came into force from 1 July 2001, the financial leasing was regulated threin as a separate type of agreement. Adoption of each new legal regulation encourages its analysis from the theoretical and scientific point of view, as well as the assessment and evaluation of its possible or present importance and impact on relations subject to regulation. Taking into consideration the variety and complexity of leasing relations, even having created the legal regulation of financial leasing in the contract law there remain may uncertainties starting with the conceptual distinction of these relations from other similar contractual relations and finishing with the solutions of separate problems that may or do arise in practice due to the existence of incompleteness and/or inconsistency of the legal regulations. The purpose of this article is to establish whether the direct leasing - one of the bipartite types of leasing - may be regarded as a type of the financial leasing in the light of the Civil Code of the Republic of Lithuania, as well as to evaluate the possible importance and impact of the provisions regulating financial leasing on the direct leasing relations. In order to evaluate the mentioned interrelation between the financial and direct leasing, this article first of all deals with the essence and the general understanding of the concept of the “financial leasing” under the Civil Code of the Republic of Lithuania, taking into consideration the practice and experience of foreign countries in regulation of financial leasing relations, as well as the provisions of UNIDROIT Convention on International Financial Leasing, adopted in Ottawa on 28 May 1988, which is prima facie dedicated to the regulation of classic triangle of international finance leasing relations in the contract law. By using the comparative, teleological and other scientific research methods, the article further reveals the purpose of the existing distinction between the financial and direct leasing under the legislation of foreign countries, as well as discusses the understanding of the direct leasing relations in the light of the Civil Code of the Republic of Lithuania, by addressing the relevant travaux préparatoires and the possible purpose of regulation of the direct leasing under the Lithuanian law and the need to distinguish the financial and/or direct leasing from other similar contractual relationship regulated under the Civil Code of the Republic of Lithuania.1990 m. kovo 11 d. atkūrus Lietuvos Respublikos nepriklausomybę Lietuvoje pradėjo plėtotis rinkos ekonomika, tačiau finansinės nuomos sutartiniai santykiai daugiau nei dešimtmetį nebuvo reguliuojami specialiomis teisės normomis. Ir tik 2001 m. liepos 1 d. įsigaliojus naujajam Lietuvos Respublikos civiliniam kodeksui finansinė nuoma buvo reglamentuota kaip atskira sutarčių rūšis. Kiekvieno naujo visuomeninių santykių teisinio reguliavimo sukūrimas skatina jo nagrinėjimą teoriniu moksliniu požiūriu bei galimą arba esamą jo reikšmės ir įtakos reguliuojamiems visuomeniniams santykiams vertinimą. Atsižvelgiant į lizingo santykių įvairovę bei sudėtingumą, net ir sukūrus finansinės nuomos teisinį reguliavimą sutarčių teisėje, išlieka gana daug neaiškumų, pradedant konceptualiu šių santykių atribojimu nuo kitų panašių sutartinių santykių ir baigiant atskirų problemų, iškylančių dėl teisinio reglamentavimo neišsamumo bei nenuoseklumo, sprendimu. Šiame straipsnyje nagrinėjama Lietuvos Respublikos civiliniame kodekse reglamentuojama finansinės nuomos sąvoka bei jos santykis su viena iš dvišalių lizingo rūšių – tiesioginiu lizingu, taip pat apžvelgiama užsienio valstybių patirtis šioje srityje. Straipsnio tikslas – nustatyti, ar Lietuvos Respublikos civilinio kodekso prasme tiesioginį lizingą būtų galima laikyti finansinės nuomos rūšimi, bei įvertinti finansinės nuomos santykius reglamentuojančių nuostatų reikšmę ir įtaką tiesioginio lizingo santykiams

Application of high-content microscopy to investigate membrane trafficking

Membrane trafficking is an abstraction describing material transport within different organelles of the cell. It is one of the areas of interest in molecular and cell biology. The practical interest for the investigation of membrane trafficking is lying in its relation to an increasing list of diseases, such as cancer. Identification of genes involved in membrane trafficking and their regulation within the cell are in particular focus of interest. Microscopy based observation of membrane trafficking events in the native or close to native context is the method of choice. It allows relating different stages of the whole process to specific cellular organelles with spatial and temporal resolution. It also has the advantage of better statistics over other population mean based methods, as results are concluded from the observation of a high number of individual cells. Despite the versatility of fluorescence microscopy, the application of any particular technique for cell biology requires more application layers such as fluorophores and labelling strategies, data acquisition and storage, digital image analysis, data interpretation in a biological context, and last but not least – the biological process of interest itself. Improvements of those application layers or even synergy of different microscopy techniques increases information content what can be extracted from a single experiment. Currently we call this approach as high-content microscopy. During the time of my studies I was working on improving some of application layers as well as creating stronger link between them. This thesis describes my experimental and data analysis work which was done to address some of the specific membrane trafficking related cases in context of high-content microscopy: a) The organization kinetics of the Golgi complex, which is the major membrane trafficking organelle, and the influence of over-expressed membrane proteins on it. Live cell fluorescence screening microscopy was employed to address this question. b) Statistical data analysis of a cargo protein secretion screen. Influence of specific RAB GTPases over-expression on collagen-I secretion was evaluated. c) The development of a comprehensive fluorescence microscopy based platform to investigate messenger RNA (mRNA) and micro RNA (miRNA) interactions in live cells

600-GHz Fourier Imaging Based on Heterodyne Detection at the 2nd Sub-harmonic

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution, which can be reached, depends on one hand on the wavelength of the radiation, but also on the capability to measure - in the focal plane - Fourier components with high spatial wave-vectors. This leads to a conflicting situation at THz frequencies, because choosing a shorter wavelength for better resolution usually comes at the cost of less radiation power, concomitant with a loss of dynamic range, which limits the detection of higher Fourier components. Here, aiming at maintaining a high dynamic range and limiting the system costs, we adopt heterodyne detection at the 2nd sub-harmonic, working with continuous-wave (CW) radiation for object illumination at 600 GHz and local-oscillator (LO) radiation at 300 GHz. The detector is a single-pixel broad-band Si CMOS TeraFET equipped with substrate lenses on both the front- and backside for separate in-coupling of the waves. The entire scene is illuminated by the object wave, and the Fourier spectrum is recorded by raster scanning of the single detector unit through the focal plane. With only 56 uW of power of the 600-GHz radiation, a dynamic range of 60 dB is reached, sufficient to detect the entire accessible Fourier space spectrum in the test measurements. A lateral spatial resolution of better than 0.5 mm, at the diffraction limit, is reached

Magneto Transport of high TCR (temperature coefficient of resistance) La2/3Ca1/3MnO3: Ag Polycrystalline Composites

We report the synthesis, (micro)structural, magneto-transport and magnetization of polycrystalline La2/3Ca1/3MnO3:Agx composites with x = 0.0, 0.1, 0.2, 0.3 and 0.4. The temperature coefficient of resistance (TCR) near ferromagnetic (FM) transition is increased significantly with addition of Ag. The FM transition temperature (TFM) is also increased slightly with Ag addition. Magneto-transport measurements revealed that magneto-resistance MR is found to be maximum near TFM. Further the increased MR of up to 60% is seen above 300 K for higher silver added samples in an applied field of 7 Tesla. Sharp TCR is seen near TFM with highest value of up to 15 % for Ag (0.4) sample, which is an order of magnitude higher than as for present pristine sample and best value yet reported for any polycrystalline LCMO compound. Increased TCR, TFM and significant above room temperature MR of La2/3Ca1/3MnO3:Agx composites is explained on the basis of improved grains size and connectivity with silver addition in the matrix. Better coupled FM domains and nearly conducting grain boundaries give rise to improved physical properties of the La2/3Ca1/3MnO3 manganites.Comment: 16 pages Text + Figs. ACCEPTED: Solid State Communications (Sept. 2006

Fabrication and study of the organic-inorganic semiconductor diodes formed on n-Si

We report fabrication and electrical characterization of the organic-inorganic semiconductor diode structures formed by evaporating thin films of three novel low molecular mass organic compounds on n-type Si substrates. The organic compounds containing carbazole and triphenylamine structural units, namely: 9,9'-bis(4-butylphenyl)-3,3'-bicarbazolyl (BPBC), 4-(1H-perimidin-2-yl)-N,N-diphenylbenzenamine (PER) and 9,9'-diethyl-3,3'-bicarbazolyl (EBC) have been synthesized. The current-voltage characteristics of the Au/(BPBC, EBC, PER)/n-Si diode structures measured at T = 295 K revealed rectifying behavior with a potential barrier height values of 0.71 eV, 0.73 eV, 0.76 eV, respectively

The potential for sensitivity enhancement by the thermoelectric effect in carbon-nanotube and graphene Tera-FETs

We report on terahertz (THz) measurements with graphene field-effect transistors with integrated antennas (Tera-FETs) lay special emphasis on thermoelectric contributions to the detected THz photoresponse. Graphene Tera-FETs with integrated broad-band bow-tie antennas were fabricated in a CVD-based growth process and were successfully applied for detection at 600 GHz with optical NEPs down to 515 pW/Hz^1/2. While rectification of THz radiation by (distributed) resistive mixing of charge-density waves induced in the gated transistor channel region is well known, significant additional contributions to the detected signal have experimentally been observed and hot-carrier thermoelectric effects have been identified as a possible origin of these signals. We also observe similar signal contributions in carbonnanotube transistors