DYNAMIC RESPONSE OF HEAVY-LIFTING SHIPYARD MACHINES TO RESONANT ENVIRONMENTAL LOAD CONDITIONS

Climate changes on the planet have led to the appearance of extreme natural influences on large structures in ports and shipyards, as well as at-sea structures. One of the most variable meteorological effects in space and time is the wind. This paper provides the manner of dynamic modelling of wind loads on a tall portal-rotating crane structure. The gust of wind is modelled as a wave quantity variable in time and altitude of flow. Dynamic wind activity on tall structures is used to obtain a structure’s behaviour with regard to extreme climate events when frequently resonant influences occur. This is performed by non-linear transient FEM analysis. Structural damping is modelled by conversion to the equivalent viscous damping. Eigenfrequencies are obtained by applying the Lanczos method which combines the tracking method and the transformation method. The paper contains an originally developed dynamic model, experimentally verified stiffness, and internal static quantities. The aim of the paper (Case Study) is to obtain the wind activity which would cause the loss of dynamic stability of the crane due to multiple resonant gusts of wind. Such analyses can be employed to determine the real risk from a potential failure in tall structures caused by environmental, meteorologically registered activities

DYNAMICAL STRUCTURAL RELIABILITY BASED ON THE CASE STUDY ANALYSIS

An important aspect of the support structures' design is their dynamic behavior under extreme conditions. Especially actual are the large-range structures. Therefore, the support structure of a mining machine for transportation of tailings (stacker) is observed dynamically. The dynamic behavior of the entire structure in an incidental situation – the failure of a support tie rod for the pylon-platform connection is observed. The aim of this research is to predict the consequences of breaking a structure element for the rest of the support structure. This paper shows the theoretical modeling of structures, numerical solution of differential equations, and vibrations after simulated incident. The paper presents special design – the way of structure testing from the aspect of high structural availability and ability of the structure to compensate overload caused by the incident. To check the model, a real stacker structure was used at the surface mine RBB (The copper mine – Bor, Serbia). The developed numerical model showed the internal stress states of the structure and the law of vibration after the incident. On the basis of more case study analyses, the overall reliability and ability of redundancy of the structure were evaluated

Révision de la Collection Jesse Harlan JOHNSON. Première partie. Quelques Dasycla-dales fossiles du Guatémala

Ce premier rapporte traite de la révision de quelques algues calcaires vertes fossiles (Dasycladales), ou supposées telles (dans les faits un de ces taxons attribué au genre Cylindroporella est un foraminifère), décrites de terrains crétacés et paléocènes du Guatémala. Dans leur papier de 1965 J.H. JOHNSON and H.V. KASKA avaient entre autres choses introduit trois nouvelles espèces attribuée à l'origine aux genres Acroporella, Cylindroporella et Cymopolia.This first report is a revision of fossil calcareous green algae (Dasycladales) described from the Upper Cretaceous and Paleocene series of Guatemala. Among other things in their 1965 paper J.H. JOHNSON and H.V. KASKA introduced three new species originally referred to the genera Acroporella, Cylindroporella, and Cymopolia. One species, which has previously been referred to the genus Cylin-droporella, is a foraminifer

Chitosan-based microparticles for immobilization of TiO2 nanoparticles and their application for photodegradation of textile dyes

The present paper deals with removal and photocatalytic degradation of the textile dyes by TiO2 nanoparticles immobilized onto chitosan-based microparticles. The microparticles composed of chitosan (Ch) and poly(methacrylic acid) (PMA) were fabricated for the first time by inverse suspension polymerization. They were utilized for colloidal TiO2 nanoparticles immobilization, synthetized by acidic hydrolysis of TiCl4. To evaluate the potential application of Ch/PMA/TiO2 microparticles for treatment of textile wastwaters, their photocatalytic activity was examined by degradation assessment of three different groups of anionic azo dyes in aqueous solutions under solar light simulating source. FTIR analysis revealed that Ch and PMA were incorporated in the polymer network. SEM and optical microscopy confirmed their spherical shape. Under illumination, Ch/PMA/TiO2 microparticles completely removed dyes C.I. Acid Orange 7, C.I. Acid Red 18, C.I. Acid Blue 113, C.I. Reactive Black 5, C.I. Direct Blue 78, while removal degree of C.I. Reactive Yellow 17 was 75%. It was found that pH had significant influence on the photocatalytic activity of Ch/PMA/TiO2 microparticles. Increase of solution pH from acidic to alkaline, lead to decrease in photodegradation rate of C.I. Acid Orange 7 during the first hours of illumination. After three illumination cycles, removal degree of C.I. Acid Orange 7 was maintained at remarkably high level (95% at pH 5.60 and 100% at pH 2.00 and 8.00), indicating that microparticles could be reused without significant loss of photocatalytic efficiency. (C) 2016 Elsevier Ltd. All rights reserved.</p

Evaluation of novel dendrimer-gold complex nanoparticles for theranostic application in oncology

To view the supplementary data that accompany this paper please visit the journal website at: www.tandfonline.com/doi/suppl/10.2217/nnm-2023-0355Aim: Despite some successful examples of therapeutic nanoparticles reaching clinical stages, there is still a significant need for novel formulations in order to improve the selectivity and efficacy of cancer treatment. Methods: The authors developed two novel dendrimerâ gold (Au) complex-based nanoparticles using twodifferent synthesis routes: complexation method (formulation A) and precipitation method (formulation B). Using a biomimetic cancer-on-a-chip model, the authors evaluated the possible cytotoxicity and internalization by colorectal cancer cells of dendrimerâ Au complex-based nanoparticles. Results: The results showed promising capabilities of these nanoparticles for selectively targeting cancer cells and delivering drugs, particularly for the formulation A nanoparticles. Conclusion: This work highlights the potential of dendrimerâ Au complex-based nanoparticles as a new strategy to improve the targeting of anticancer drugs.This work is financially supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 952603 (http://sgabu.eu/). This article reflects only the author’s view. The Commission is not responsible for any use that may be made of the information it contains. For the experimental part of the study, we acknowledge BIONECA project – Biomaterials and advanced physical techniques for regenerative cardiology and neurology (CA16122) – and the FEDER funded project 2IQBIONEURO (0624 2IQBIONEURO 6 E). M Carvalho acknowledges her postdoctoral contract TERM RES Hub – Scientific infrastructure for Tissue Engineering and Regenerative Medicine Ref Norte-01-0145-FEDER-02219015. D Caballero acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) under the program CEEC Individual 2017 (CEECIND/00352/2017), and the project 2MATCH (PTDC/BTM-ORG/28070/2017) funded by the Programa Operacional Regional do Norte supported by European Regional Development Funds (ERDF). This work was partially supported by IET A. F. Harvey Engineering Research Award 2018 (ENG The Cancer). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed