199 research outputs found
Growth of thin film containing high density ZnO nanorods with low temperature calcinated seed layer
No full textInducing two-way shape memory effect in Nitinol-Polymer Composite
No full textTitle: Inducing Two-way Shape Memory Effect in NiTi-polymer Composite Author: Jakub Zeman Supervisor: Sneha Manjaree Samal, Ph.D., Institute of Physics of the Czech Academy of Sciences Abstract: Two-way shape memory effect (TWSME) allows material to ac- tively deform between two remembered shapes without the application of ex- ternal force. The most common stimulus is temperature change with several approaches to induce shape memory effect in the material. The approach stud- ied in this thesis utilizes Nitinol and shape memory polymer. By combining these two materials, bistable TWSME was induced in the composite. Bistable TWSME allows the material to be in both of its remembered shapes at a single temperature. The shape of the material depends on the temperature profile by which the target temperature was reached. To create the composite Nitinol foil was shape set and its surface laser lined to increase adhesion with the polymer. Out of the studied polymers, the best properties for the preparation of com- posite were exhibited by a blend of 60 % TPU and 40 % PCL by weight. The composite was then prepared by hot press and tested. Keywords: inducing two-way shape memory effect, Nitinol, shape memory polymer, composite
Immune mechanisms and potential immunological treatment in atherosclerosis
No full textOur immune system is an important and central part of the defence mechanisms of our body. It carries out various important functions such as protecting us from invading microorganisms, removing dead cells, and producing antibodies for future defence. For this, proper synchronization between the innate and adaptive immunity is required. Our innate immune system acts as the first line of defence by eliminating non-specifically various pathogens and by activating antigen-presenting cells (APCs) that inform B-cells and T-cells of the adaptive immune system. B-cells can exhibit more specific actions against pathogens by an intricately regulated production of antibodies directed against antigens expressed by the pathogens. T-cells can produce cytokines and chemokines to alarm the complete immune system recruiting immune cells such as natural killer cells, mast cells and neutrophils. The immune system can also produce antibodies against self-antigens (autoantibodies). Autoantibodies can have pathogenic effects that cause autoimmune diseases such as Systemic Lupus Erythematosis. Interestingly, it has been shown recently that autoantibodies can also have protective effects alleviating diseases such as lupus nephritis and atherosclerosis. This thesis focuses specifically on homeostatic functions of the human autoantibodies anti-phoshorylcholine (anti-PC) and anti-malondialdehyde (anti-MDA) and their prevalence in cardiovascular disease (CVD) and chronic kidney disease (CKD).1. Study I: Investigates the role of anti-PC and anti-MDA antibodies in patients undergoing hemodialysis and explores the associations with all-cause mortality in both males and females, also their relation to inflammation.2. Study II: Evaluates the potential of natural immunization in hibernating bears, tigers, and polar bears with respect to the levels of anti-PC and anti-MDA antibodies.3. Study III: Evaluates the role of antibodies against anti-PC antibodies among 60-Year-Olds with its clinical role and simulated interactions.4. Study IV: Investigates the role of anti-PC antibody levels in Covid-19 patients and also investigates the interaction of spike protein with phosphorylcholine by using an in silico approach.List of scientific papersI. Samal SK, Qureshi AR, Rahman M, Stenvinkel P and Frostegard J. Different subclasses and isotypes of antibodies against phosphorylcholine in haemodialysis patients: association with mortality. Clin exp Immunol. 2020;201:94. https://doi.org/10.1111/cei.13441 II. Samal SK, Qureshi AR, Rahman M, Stenvinkel P and Frostegard J. Antibodies against Malondialdehyde in Haemodialysis Patients and Its Association with Clinical Outcomes: Differences between Subclasses and Isotypes. J Clin Med. 2020;9:753. https://doi.org/10.3390/jcm9030753 III. Samal SK, Frobert O, Kindberg J, Stenvinkel P and Frostegard J. Potential natural immunization against atherosclerosis in hibernating bears. Sci Rep. 2021;11:12120. https://doi.org/10.1038/s41598-021-91679-1 IV. Samal SK, Panda PK, Vikström M, et al. Antibodies Against Phosphorylcholine Among 60-Year-Olds: Clinical Role and Simulated Interactions. Frontiers in Cardiovascular Medicine. 2022; 9. https://doi.org/10.3389/fcvm.2022.809007 V. Samal SK*, Busch M*, Panda KP, Kumar N, Timmermans S, Schurgers LJ, Reutelingsperger CR, Paassen PV*, Frostegård J*. Antibodies against phosphorylcholine are associated with less severe disease in COVID-19: clinical role and simulated interactions using In-silico methods. *Denotes equal author contribution. [Manuscript]</p
Vyvolání obousměrné tvarové paměti v NiTi-polymerovém kompozitu
No full textNázev práce: Vyvolání obousměrné tvarové paměti v NiTi-polymerovém kompozitu Autor: Jakub Zeman Katedra: Katedra fyziky materiálů, Matematicko-fyzikální fakulta, Uni- verzita Karlova Vedoucí bakalářské práce: Sneha Manjaree Samal, Ph.D., Fyzikální ústav Akademie věd České republiky Abstrakt: Obousměrná tvarová paměť umožňuje deformaci materiálu mezi dvěma zapamatovatelnými tvary bez působení vnějších sil, přičemž aktivaci změny tvaru se využívá nejčastěji změna teploty. Mezi řadou způsobů, jak dosáhnout obousměrné tvarové paměti, byla v této práci využita kombinace kovového materiálu Nitinol a vybraného polymeru s tvarovou pamětí. V kom- pozitním materiálu z těchto dvou složek bylo dosaženo bistabilní obousměrné tvarové paměti. Bistabilní obousměrná tvarová paměť je unikátní tím, že umožňuje existenci materiálu v obou zapamatovaných stavech při stejné teplotě. Bylo prokázáno, že rozhodujícím faktorem pro dosažení určitého tvaru je předešlý teplotní průběh kompozitního materiálu. Pro zlepšené spojení kovového Niti- nolu a polymerního materiálu byl povrch NiTi upraven laserem. Mezi několika studovanými polymery prokázal nejlepší vlastnosti polymer vyrobený ze dvou složek, a to 60...Title: Inducing Two-way Shape Memory Effect in NiTi-polymer Composite Author: Jakub Zeman Supervisor: Sneha Manjaree Samal, Ph.D., Institute of Physics of the Czech Academy of Sciences Abstract: Two-way shape memory effect (TWSME) allows material to ac- tively deform between two remembered shapes without the application of ex- ternal force. The most common stimulus is temperature change with several approaches to induce shape memory effect in the material. The approach stud- ied in this thesis utilizes Nitinol and shape memory polymer. By combining these two materials, bistable TWSME was induced in the composite. Bistable TWSME allows the material to be in both of its remembered shapes at a single temperature. The shape of the material depends on the temperature profile by which the target temperature was reached. To create the composite Nitinol foil was shape set and its surface laser lined to increase adhesion with the polymer. Out of the studied polymers, the best properties for the preparation of com- posite were exhibited by a blend of 60 % TPU and 40 % PCL by weight. The composite was then prepared by hot press and tested. Keywords: inducing two-way shape memory effect, Nitinol, shape memory polymer, composite 1Department of Physics of MaterialsKatedra fyziky materiálůMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Chaos in classical string dynamics in γˆ deformed AdS5×T1,1
No full textAbstractWe consider a circular string in γˆ deformed AdS5×T1,1 which is localized in the center of AdS5 and winds around the two circles of deformed T1,1. We observe chaos in the phase space of the circular string implying non-integrability of string dynamics. The chaotic behaviour in phase space is controlled by energy as well as the deforming parameter γˆ. We further show that the point like object exhibits non-chaotic behaviour. Finally we calculate the Lyapunov exponent for both extended and point like object in support of our first result
Low‐mass young stellar population and star formation history of the cluster IC 1805 in theW4 HII region
No full textInternational audienceW4 is a giant HII region ionized by the OB stars of the cluster IC 1805. The HII region/cluster complex has been a subject of numerous investigations as it is an excellent laboratory for studying the feedback effect of massive stars on the surrounding region. However, the low‐mass stellar content of the cluster IC 1805 remains poorly studied till now. With the aim to unravel the low‐mass stellar population of the cluster, we present the results of amultiwavelength study based on deep optical data obtained with the Canada‐France‐Hawaii Telescope, infrared data from Two Micron All Sky Survey and Spitzer Space Telescope and X‐ray data from Chandra Space Telescope. The present optical data set is complete enough to detect stars down to 0.2 M‐circle dot, which is the deepest optical observation so far for the cluster. We identified 384 candidate young stellar objects (YSOs; 101 Class I/II and 283 Class III) within the cluster using various colour‐colour and colour‐magnitude diagrams. We inferred the mean age of the identified YSOs to be similar to 2.5 Myr and mass in the range 0.3‐2.5 M‐circle dot. The mass function of our YSO sample has a power‐law index of ‐1.23 +/‐ 0.23, close to the Salpeter value (‐1.35), and consistent with those of other star‐forming complexes. We explored the disc evolution of the cluster members and found that the disc‐less sources are relatively older compared to the disc bearing YSO candidates. We examined the effect of high‐mass stars on the circumstellar discs and within uncertainties, the influence of massive stars on the disc fraction seems to be insignificant. We also studied the spatial correlation of the YSOs with the distribution of gas and dust of the complex to conclude that IC 1805 would have formed in a large filamentary cloud
When Censorship Produces. Exemplified on Zakázané prózy by Vladimír Mináč
No full textThe article uses a collection of stories by Vladimír Mináč titled Z nedávnych čias /Of the Recent Times/ banned in 1957 by Head Office of Print Media Supervision as an example so as to show productive effects of censorship. The author develops the ideas of the methodological movement New Censorship (Richard R. Burt) and shows different kinds of meaning that the censorship case produced. The author claims that the censorship interventions made in 1957 are associated with various forms of fetishism, which followed the recent publishing of the book by Vladimír Mináč Zakázané prózy (Banned proses, Ed. Pavel Matejovič, Bratislava : Slovenské informačné centrum 2015) and engaged the work of art that would be otherwise left forgotten in literary communication. Special attention is paid to the legitimizing and cannonizing effects that were prompted by the censorship
Empowering microgrids: harnessing electric vehicle potential through vehicle-to-grid integration
No full textElectric vehicles (EVs) can potentially be integrated into microgrids via vehicle-to-grid (V2G) technology, which enhances the energy system's stability and durability. This paper provides an in-depth examination and evaluation of V2G integration in microgrid systems. It analyses the present state of research as well as possible uses, challenges, and directions for V2G technology in the future. This paper addresses the technological, economic, and regulatory aspects of implementing V2G and provides case studies and pilot projects to shed light on potential benefits and barriers associated with its adoption. The research highlights how V2G contributes to more efficient integration of renewable energy sources, grid stabilization, and cost savings for EV owners. It also addresses the latest developments in technology and proposed laws aimed at encouraging growing applications of V2G
DMWT’, ṢLM, NṢB. 'Estatua' en la epigrafía aramea
No full textThe nouns dmwt’, nṣb, ṣlm were used with the meaning of 'statue' in the epigraphic texts written in Old and Official Aramaic, nevertheless we do not find all these three nouns either in every dialect of ancient Aramaic (Samal, Tell Fekherye and Common Old Aramaic -ZKR, Sefire, Barhadad-) or in Official Aramaic. In this paper the author discusses the use of each of these words in each of the different Armaic types already mentioned, and how ṣlm as 'statue' became the usual term in Official Aramaic, due to the Assyrian influence upon the Aramaic language, ṣalmu being the word in Assyrian for 'statue'. The Tell Fekherye Assyrian-Aramaic inscription stands out as a relevant witness for the use of ṣlm in Aramaic under the Assyrian influence.En los textos epigráficos arameos del periodo del arameo antiguo y oficial se usan dmwt’, nṣb, ṣlm, con el significado de 'estatua', aunque no todos estos términos se emplean en el arameo antiguo común, en Samal, en la inscripción de Tell Fekherye y en el arameo oficial. En el presente articulo se habla de la distribución de esos nombres en las distintas clases de modalidades de arameo mencionadas, y de cómo el uso de ṣlm llegó a ser el único que prácticamente se utilizó en arameo oficial como resultado de la fuerte influencia del asirio, que usaba ṣalmu para «estatua», influencia y uso que nos han quedado atestiguados en la inscripción bilingüe asiro-aramea de Tell Fekherye
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