Paola Bertoli, Veronica Grembi., Obsahuje bibliografii a bibliografické odkazy., České resumé, and Vydává: Univerzita Karlova, Centrum pro ekonomický výzkum a doktorské studium, Národohospodářský ústav AV ČR
Two different pathways for protochlorophyllide a (Pchlide) reduction in photosynthetic organisms have been proved: one is strictly light-dependent whereas the second is light-independent. Both pathways occur in all photosynthetic cells except in angiosperms which form chlorophyll only through the light-dependent pathway. Most cells belonging to Eubacteria (i.e., the anoxygenic photosynthetic bacteria) synthesize bacteriochlorophyll through the light-independent pathway. This review deals with the physiological, biochemical, and molecular biological features of molecules involved in both pathways of Pchlide reduction.
In slurry transport of settling slurries in Newtonian fluids, it is often stated that one should apply a line speed above a critical velocity, because blow this critical velocity there is the danger of plugging the line. There are many definitions and names for this critical velocity. It is referred to as the velocity where a bed starts sliding or the velocity above which there is no stationary bed or sliding bed. Others use the velocity where the hydraulic gradient is at a minimum, because of the minimum energy consumption. Most models from literature are one term one equation models, based on the idea that the critical velocity can be explained that way. Here the following definition is used: The critical velocity is the line speed below which there may be either a stationary bed or a sliding bed, depending on the particle diameter and the pipe diameter, but above which no bed (stationary or sliding) exists, the Limit Deposit Velocity (LDV). The way of determining the LDV depends on the particle size, where 5 regions are distinguished. These regions for sand and gravel are roughly; very small particles up to 0.014-0.040 mm (d < δv), small particles from δv-0.2 mm, medium particles in a transition region from 0.2-2.00 mm, large particles > 2 mm and very large particles > 0.015·Dp. The lower limit of the LDV is the transition between a sliding bed and heterogeneous transport. The new model is partly based on physics and correlates well with experiments from literature.
Utilization of a magnetic force can be found in many mechatronic applications, where e.g. a slender beam or plate is subjected to static magnetic force generated by an electromagnetic actuator consisting of a solenoid wound on a ferromagnetic core and a ferromagnetic armature, fixed to the beam. The static magnetic force, acting perpendicularly onto the beam, causes sag (downwards bending) of the beam. If the magnitude of the magnetic force surpasses some threshold value the armature and hence the beam is completely attracted to the core of the solenoid. For small detections the mathematical expression of the magnetic force can be linearised and approximated by a polynomial dependence on the distance to the electromagnet. In practical application, it is important to analyse the nature of the sag and to determine the limits of the linear approxmation, as well as the limits leading to the full attraction to the electromagnet. The mathematical generalisation of the sag is valid for electrostatic force between planar electrodes, too. and Obsahuje seznam literatury
This catalogue is computer-based and issued in collaboration with the CDS in Strasbourg. The outlay of the catalogue will be described, particularly the tracer system for data base handling. A new examination of cluster appearances on survey charts has been entered in the 1983 edition. Various parameters will be compared and their accuracy discussed.
Sequencing of SSU rDNA showed that actinospores of the tetractinomyxon type, which develop in Chone infundibuliformis Krøyer (Annelida, Polychaeta, Sabellidae) from the northern Øresund, Denmark, are identical with Ceratomyxa auerbachi Kabata, 1962 (Myxozoa, Ceratomyxidae). This myxosporean was found in the gallbladder of the Atlantic herring Clupea harengus L. from the northern Øresund, Denmark, and from the Bergen area, western Norway. The pansporocysts and actinospores of C. auerbachi are described. This is the third elucidated two-host life cycle of a marine myxozoan, and the first involving a marine ceratomyxid.
The article presents the mathematical model non-homogenous, isotropic environment, where is possible to create various types of flows (the chemical reaction flow, the diffusion flow, the heat flow, the electromagnetic flow). and Obsahuje seznam literatury
The paper presents a method of experimental and model investigations, enabling the monitoring of rehabilitation process, for parents with upper limbs diseases, having neurological base. The changes of forces, generated by particular groups of upper limb muscles, during typical rehabilitation exercises, were assumed as an indicator of the rehabilitation progress. The mathematical model and the set of computer programs were elaborated, which enable identification of forces generated by muscles and realization of comparative analysis, within a framework of inverse dynamic problem, and with the use of optimization techniques and computer processed video-registration of limb movement. and Obsahuje seznam literatury
This paper investigates the matrix porosity and related properties of a leucocratic granite from the Krudum Massif, West Bohemia. The required samples were obtained from the 30-year old core of borehole KZ-25 (Material Documentation Depositories). In total, nine sample sets were taken from different depth levels within the borehole ranging from 18 m to 108 m. The hydraulic conductivity of the granite matrix was measured using a pressure cell whilst standard methods were employed to determine the dry density, connected porosity and total porosity. The pore size distribution was analysed using mercury porosimetry. The ultrasonic velo cities were measured using a pulse source and oscilloscope. Dynamic Young’s modulus, dynamic shear modulus, Poisson’s ratio, static Young’ s modulus, uniaxial compressive strength and moisture were determined according to measurements of ultrasonic velocities and deformability in uniaxial compression. The morphology and structure of the pore network was studied using high reso lution scanning electron microscopy. The overall porosity values defined by the different porosimetry methods follow the same trends although the absolute values differ according to the specific method. A logarithmic relationship was found to exist between hydraulic conductivity and porosity within the granite matrix. In addition, a slight depth dependence was noted in the porosity, hydraulic conductivity, bulk density, and ultrasonic velocities of the granite matrix. The SEM images have allowed precise mapping and detailed de scription of the pore network., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografické odkazy
In the previous paper, a design of the special amplifier, intended for pyroelectric signal measurement, has been presented. [1] This paper presents the results, achieved using this amplifier for the measurements of signal characteristics of pyroelectric sensors in our testing lab. The amplifier is being used for the measurements connected to the solution to the specific tasks i.e.: Development of technology of spatial localization of various infrared sources, testing of infrared sources and their reliability, moistening immunity, signal-noise measurement under different condition etc. and V předcházejícím článku byl předložen návrh speciálního předzesilovače navrženého pro účely měření pyroelektrik. Tento článek předvádí výsledky dosažené za pomoci tohoto zesilovače signálu ze snímačů v naší testovací laboratoři. Zesilovač je používán pro nejrůznější měřicí úlohy, např. pro technologii prostorové lokalizace infračervených zářičů, pro testování infračervených zdrojů záření a jejich spolehlivosti, při testování odolnosti krytu snímače proti navlhání, pro měření snímače za nejrůznějších podmínek atd.