73 research outputs found
On -derivations of group algebra as category characters
For the space of -derivations of the group algebra of discrete countable group , the decomposition theorem for
the space of -derivations, generalising the corresponding
theorem on ordinary derivations on group algebras, is established in an
algebraic context using groupoids and characters. Several corollaries and
examples describing when all -derivations are inner are
obtained. Considered in details cases on nilpotent groups and
- groups
Consideration of soil strata heterogeneity influence on differential foundation settlements of overpasses for high-speed railways
The implementation of projects for the construction of high-speed railways actualizes the search of effective approaches to accounting the influence of soil strata heterogeneity along the course of the track on differential foundation settlements of overpasses. Russian special technical conditions prescribe sufficiently stringent regulation limits of absolute values of overpasses' foundation soil settlements (20 mm for ballastless track) and angles of break in profile (the differential foundation soil settlement), which should not exceed 1 ‰ for ballastless track. These requirements make it necessary to develop the calculation method, which is based on the criterion of deformation. To ensure compliance of design solutions to the specified regulations it is appropriate to use the method of the predefined equated soil settlements for design of shallow foundations of overpasses for high-speed railways. Several features of application of this method are presented in this article
Fauna of Ground Beetles (Coleoptera, Carabidae) in Broad-leaved Forests of the Republic of Mordovia (Central European Russia)
The fauna of Carabidae adults in broad-leaved forests of the Republic of Mordovia (central European Russia) was studied. A total of 18210 ground beetle specimens of 104 species (8 subfamilies) were collected. The most numerous species were eight species: Carabus cancellatus, Pterostichus niger, Pterostichus oblongopunctatus, Limodromus assimilis, Calosoma inquisitor, Carabus granulatus, Pterostichus melanarius, Carabus arvensis. The basis of the Carabidae fauna consists of 25 species with high occurrence (50% and higher). Among them, four species are characterized by 100% occurrence: Carabus granulatus, Carabus hortensis, Pterostichus niger, Pterostichus oblongopunctatus
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Searching for Magnetospheres around Herbig Ae/Be Stars
We describe four different approaches for the detection of magnetospheric accretion among Herbig Ae/Be stars with accretion disks. Studies of several unique objects have been carried out. One of the objects is the Herbig Ae star HD 101412 with a comparatively strong magnetic field. The second is the early-type Herbig B6e star HD 259431. The existence of a magnetosphere in these objects was not recognized earlier. In both cases, a periodicity in the variation of some line parameters, originating near the region of the disk/star interaction, has been found. The third object is the young binary system HD 104237, hosting a Herbig Ae star and a T Tauri star. Based on the discovery of periodic variations of equivalent widths of atmospheric lines in the spectrum of the primary, we have concluded that the surface of the star is spotted. Comparing our result with an earlier one, we argue that these spots can be connected with the infall of material from the disk onto the stellar surface through a magnetosphere. The fourth example is the Herbig Ae/Be star HD 37806. Signatures of magnetospheric accretion in this object have been identified using a different method. They were inferred from the short-term variability of the He I λ5876 line profile forming in the region of the disk/star interaction
Some types of carbon-based nanomaterials as contrast agents for photoacoustic tomography
This paper is devoted to the study of various carbon-based nanomaterials as photoacoustic contrast agents. The research work was performed on agarose-based tissue phantom containing inclusions with and without carbon-based nanomaterials. The inclusion was created with the higher density compared to phantom in order to simulate a tumor. A specially designed photoacoustic probe was introduced for measuring a level of photoacoustic signal and its enhancement caused by the nanoinclusions presence. The probe consists of a buffer for time separation of the signal coming from the excitation source, piezoelectric transducer, and amplifier. A point-by-point measurement of the signal was performed to obtain a two-dimensional map from magnitude of photoacoustic signal and phase delay of the signal registration. From phase delay the 3D photoacoustic images were reconstructed by evaluation of the depth coordinate based on the tissue sound velocity. As an excitation source the light radiation from Nd:YAG laser with a 16 ns pulse duration and a 1064 nm wavelength was used. Firstly, we considered tissue phantom with a tumor covered by graphene oxide as a reference one. It has been shown that the use of graphene oxide leads to significant improvement of the image contrast. Further, the tumors labelled with nanodiamonds (NDs) and carbon fluoroxide (CFO) nanoparticles (NPs) were studied systematically. Amplitude of the photoacoustic signals registered from such tumor phantoms are one order of magnitude lower than the signal ensured by graphene oxide. All three types of the studied carbon-based nanomaterials (GO, NDs, CFO) give stable photoacoustic signal, this allows to consider them as good candidates for further in-vitro experiments in photoacoustic imaging for biological applications. The dependences of the signal level as a function of the NPs concentration were measured for types of NPs. Considering much more efficient penetration of NDs and CFO NPs inside the cells as well as their extremely low cytotoxicity, these both types of carbon nanomaterials could be used for further in-vivo experiments
Retrospective analysis of surgical treatments of sternoclavicular joint dislocation: literature review
Traumatic injuries to the sternoclavicular joint (SCJ) dislocations account for less than 3% of all joint dislocations. However, instrumentation fixation is frequently associated with high-risk complications that lead to disability. The authors sought to explore historical aspects of various surgical fixation techniques based on specific anatomy of injured segment. The findings are presented in the chronological order briefly describing methods of fixation, the authors and clinical results obtained
The Discrete Analysis of the Tissue Biopsy Images with Metamaterial Formalization:Identifying Tumor Locus
Herein, we develop an enhanced and automated methodology for detection of the tumour cells in fixed biopsy samples. Metamaterial formalism (MMF) approach allowing recognition of tumour areas in tissue samples is enhanced by providing an advanced technique to digitize mouse biopsy images. Thus, a colour-based segmentation technique based on the K-means clustering method is used allowing for a precise segmentation of the cells composing the biological tissue sample. Errors occurring at the tissue digitization steps are detected by applying MMF. Doing so, we end up with the robust, fully automated approach with no needs of the human intervention, ready for the clinical applications. The proposed methodology consists of three major steps, i. e. digitization of the biopsy image, analysis of the biopsy image, modelling of the disordered metamaterial. It is worthwhile mentioning, that the technique under consideration allows for the cancer stage detection. Moreover, early stage cancer diagnosis is possible by applying MMF
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