QUALITY OF HYBRID SIMULATION: A REACHABILITY ANALYSIS APPROACH

Abstract We address the issue of the quality of hybrid simulation, an experimental method used in earthquake engineering to examine the response of structural systems to dynamic excitation. After describing the typical sources and the effects of measurement and actuation errors, we present a reachability-based formulation of error propagation in hybrid simulation. This approach predicts possible (sets of) states of a structural system under dynamic loading for all (sets of) perturbations acting on the system. We compute ellipsoidal approximations of these sets. Finally, we demonstrate the reachability analysis approach on a few canonical dynamic problems

Accounting for path and site effects in spatial ground-motion correlation models using Bayesian inference

Ground-motion correlation models play a crucial role in regional seismic risk modeling of spatially distributed built infrastructure. Such models predict the correlation between ground-motion amplitudes at pairs of sites, typically as a function of their spatial proximity. Data from physics-based simulators and event-to-event variability in empirically derived model parameters suggest that spatial correlation is additionally affected by path and site effects. Yet, identifying these effects has been difficult due to scarce data and a lack of modeling and assessment approaches to consider more complex correlation predictions. To address this gap, we propose a novel correlation model that accounts for path and site effects via a modified functional form. To quantify the estimation uncertainty, we perform Bayesian inference for model parameter estimation. The derived model outperforms traditional isotropic models in terms of the predictive accuracy for training and testing data sets. We show that the previously found event-to-event variability in model parameters may be explained by the lack of accounting for path and site effects. Finally, we examine implications of the newly proposed model for regional seismic risk simulations.</p

Polarographic determination of cadmium in biological material

Opisana je polarografska metoda za direktno određivanje kadmijuma u mokraći i krvi. Kadmijum se u mokraći kvantitativno taloži kalcium hloridom u slabo kiseloj sredini. Talog se odvaja centrifugovanjem, Organske materije u talogu mineralizuju se perhlornom kiselinom. Uzorak krvi delimično se mineralizuje azotnom kiselinom, gvožđe prevede u hlorid i ekstrahuje etiletrom zajedno sa masnim materijama. Potpuna mineralizacija vrši se sumpornom i perhlornom kiselinom. Mineralizovani ostatak rastvori se u 1 M NaCI i kadmijum odredi polarografski.A polarographic method for direct determination of cadmium in urine and blood is described. In urine cadmium is quantitatively precipitated by calcium chloride in a weakly acid medium. The precipitate is separated by the procedure of centrifugation. The content of organic matter in the precipitate is mineralized by perchloric acid. A blood sample is partly mineralized by nitric acid iron is transformed into chloride and extracted by means of ethyl ether together with the fat matter. Complete mineralization can be done with sulphuric and perchloric acid. The mineralized residue is dissolved in 1 M NaCl and cadmium is determined by polarography

Characteristics and empiric antimicrobial therapy of urinary tract infections in patients treated at the Departement of Infectious Diseases, General Hospital »Dr. Josip Benčević« in Slavonski Brod

Infekcije mokraćnog sustava (IMS) jedan su od najčešćih razloga traženja liječničke pomoći, pa stoga i među najčešćim razlozima propisivanja antibiotika. Istaknuta je analiza najčešćih uzročnika IMS u našoj sredini, uočavanje stupnja rezistencije na pojedine antibiotike, te ocjena uspješnosti ordinirane empirijske antimikrobne terapije. Retrospektivno su obrađeni podaci o bolesnicima liječenim na Odjelu za zarazne bolesti Opće bolnice »Dr. Josip Benčević« u Slavonskom Brodu, zbog akutnih infekcija mokraćnog sustava, tijekom 2004. godine. Najčešći je uzročnik IMS bila Escherichia coli, premda je u muškaraca s kompliciranim IMS bio najčešći uzročnik Pseudomonas aeruginosa. Obzirom da je 45 % izoliranih bakterija Escherichia coli bilo rezistentno na amoksicilin, a 35 % na kotrimoksazol, ovi antibiotici se u našoj sredini ne mogu upotrebljavati u empirijskoj antimikrobnoj terapiji IMS. Čak 65 % izoliranih bakterija Pseudomonas aeruginosa nije bilo osjetljivo na gentamicin, a 45 % na ciprofloksacin. Najčešći neuspjeh empirijske antimikrobne terapije zabilježen je u muškaraca s kompliciranim IMS, pa bi nam bio najbolji izbor empirijskog antimikrobnog liječenja ovih bolesnika kombinacija piperacilina s tazobaktamom, karbapenemi ili cefepim.Urinarv tract infections (UTI) are one of the most common reasons for seeking medical consultation and therefore are among the most frequent reasons for antibiotic prescription. The purpose of this paper is the analvsis of the most common etiologic agents of UTI in our environment, registration of the degree of bacterial resistance, and evaluation of empiric antibiotic therapv success. Retrospectively data of patients, hospitalized during year 2004, at the Departement of Infectious Diseases, General Hospital »Dr. Josip Benčević« in Slavonski Brod, due to acute urinarv tract infections, were analysed. The most common cause of UTI was Escherichia coli, although in male patients with complicated UTI, the most common cause was Pseudomonas aeruginosa. Since 45% of Escherichia coli were amoxicillin resistant, and 35% trimethoprim-sulfamethoxazole resistant, these antimicrobials can\u27t be used as empiric therapy drugs in our environment. As much as 65% of Pseudomonas aeruginosa were gentamicin and 45% ciprofloxacin resistant. The most frequent empiric antibiotic therapy failure was observed in male patients with complicated UTI, so the best empiric drug choice for these patients, in our situation, would be piperacillin/tazobactam, carbapenems or cefepime

Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics

Zinc oxide is one of the most studied materials due to its wide bandgap (3.37 eV) and large exciton binding energy (60 meV) which enables application in electronics, optoelectronics and spintronics. In the forms of single crystal and thin-film ZnO are used as UV and blue light emitter, while sintered ZnO-based ceramics are important as varistors, thermistors or semiconductors. It has been found that point defects in the crystal structure of a ZnO strongly influenced its electrical and optical properties. Neutral oxygen vacancies are considered to be a major component of the defect structure of ZnO. Thus, correlation of the oxygen vacancies concentration with band gap energy of ZnO product is important to its application in optoelectronic devices. In this study we investigated the influence of point defects concentration in ZnO crystal structure on its optical and photocatalytic properties. We analyzed ZnO powders prepared by different techniques: (a) microwave processing of precipitate and (b) hydrothermal processing, which yield different ordered crystal structure. To increase a concentration of the point defects in the crystal structure, the powders were sintered in air atmosphere by heating rate of 10 °/min up to 1100 °C, with dwell time of 1 h. The crystal structure, average crystallite size and phase purity of the ZnO ceramics were determined by X-ray diffraction and Raman spectroscopy. The optical properties, in particular, absorption capacity and bang gap energy, were studied using UV–Vis diffuse reflectance spectroscopy. To reveal the role of microstructures and point defects in ZnO crystal lattice, which are receptive for luminescence and photocatalytic activity of this functional oxide, photoluminescence (PL), photoluminescence excitation (PLE) and EPR spectra were analyzed. The influence of point defects concentration in the ZnO crystal structure on photocatalytic properties was examined via decolorization of methylene blue under direct sunlight irradiation. Correlation between amount of the point defects, absorption capacity and photocatalytic efficiency were established. In order to clarify the experimental results ab initio calculations based on density functional theory (DFT) were performed

Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)

Even has been under study since 1935, zinc oxide (ZnO) based materials still attract a huge scientific attention. Owing to a wide band gap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) ZnO has a variety of application, e.g. in electronics, optoelectronics, spintronics and photocatalysis. Besides, it has been shown that zinc oxide-based materials have a great potential as photoelectrocatalysts in the processes of water splitting, yielding an increased both photocurrent density and photoconversion efficiency. However, with a band gap energy of 3.37 eV, ZnO is restricted to absorb UV light only. This restriction can be overcome by modifying optical properties of zinc oxide particles. During the years different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials, for example: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc. In this study we employed 3d metal ion substitution to improve visible light-driven photoactivity of zinc oxide particles. We investigated the influence of Fe concentration in Zn1-xFeyO(1-x+1.5y) nanoparticles on crystal structure, textural, optical and photoelectrocatalytic properties. Zn1-xFeyO(1-x+1.5y) nanoparticles with nominally 5, 10, 15 and 20 at.% of Fe ions were synthesized by microwave processing of a precipitate. The crystal structure and phase purity of the samples were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. Mössbauer spectroscopy was carried out to clarify the valence state of the iron ions in the ZnO crystal structure. Effects of the iron ions concentration on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) with elemental mapping, and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Photoelectrochemical activity of the Zn1-xFeyO(1-x+1.5y) samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared. In addition, a series of first principles calculations were performed to address the influence of the iron concentration on the electronic structure of Zn1-xFeyO(1-x+1.5y) samples

Proteomic insight into allergenic food corona on polyethylene terephthalate microplastics

Microplastics is abundant in the environment, food and beverages and get ingested by humans. Its complex interplay with proteins lead to formation of corona. Tightly bound proteins represent hard corona, while weaker binding partners are found in soft corona. Separation of hard and soft corona of allergenic proteins of shrimps, eggs and cow’s milk, tropomyosin (TPM), ovalbumin (OVA) and beta-lactoglobulin (BLG) and identification of binding partners by proteomics was aim of our study. Allergenic proteins were purified from egg white, shrimps and cow’s milk. Binding to polyethylene terephthalate microplastics (PET) (70-100 m) was probed at pH 7 for purified allergens and egg white proteins. After establishment of binding equilibrium, soft and hard corona were separated and analyzed by SDS PAGE, followed by identification of bound proteins by nanoLC-HRMS. Binding of all allergenic proteins was observed in both soft and hard corona. Soft corona contains exclusively intact, full length OVA, TPM and BLG. Hard corona is enriched for truncated OVA and oligomers of TPM. OVA fragments are partially or fully enfolded and have higher level of exposed hydrophobic patches resulting in higher affinity for PET microplastics. In comparison to OVA and TPM, hard corona of BLG is less abundant under similar conditions. BLG is compact globular protein with lower level of exposed hydrophobic patches in comparison to ovalbumin and tropomyosin. In hard corona, trace amounts of contaminating alfa-lactalbumin become enriched. In the presence of egg white protein extract OVA forms both SC and HC on microplastics, being the dominant protein of hard corona (with ovotransferrin). Lysozyme and ovomucin are present only in hard corona. Both proteins are known for their strong bioactivity and represent a small fraction of total egg white proteins. Our results show that allergenic proteins form hard corona on PET microplastics. Among egg white proteins, minor proteins such as lysozyme and ovomucin become enriched. Denaturing effect of strong binding to microplastics may change functional characteristics of allergens and bioactive proteins of foods and should be further investigated in functional assays.[https://itpa.it/index.php/past-events/xvii-itpa-hps-and-sepa-international-congress-rome-italy-november-29-december-1-2023/

Sandwich ELISA for the Quantification of Nucleocapsid Protein of SARS-CoV-2 Based on Polyclonal Antibodies from Two Different Species

In this study, a cost-effective sandwich ELISA test, based on polyclonal antibodies, for routine quantification SARS-CoV-2 nucleocapsid (N) protein was developed. The recombinant N protein was produced and used for the production of mice and rabbit antisera. Polyclonal N protein-specific antibodies served as capture and detection antibodies. The prototype ELISA has LOD 0.93 ng/mL and LOQ 5.3 ng/mL, with a linear range of 1.52–48.83 ng/mL. N protein heat pretreatment (56 °C, 1 h) decreased, while pretreatment with 1% Triton X-100 increased analytical ELISA sensitivity. The diagnostic specificity of ELISA was 100% (95% CI, 91.19–100.00%) and sensitivity was 52.94% (95% CI, 35.13–70.22%) compared to rtRT-PCR (Ct < 40). Profoundly higher sensitivity was obtained using patient samples mostly containing Wuhan-similar variants (Wuhan, alpha, and delta), 62.50% (95% CI, 40.59 to 81.20%), in comparison to samples mostly containing Wuhan-distant variants (Omicron) 30.00% (6.67–65.25%). The developed product has relatively high diagnostic sensitivity in relation to its analytical sensitivity due to the usage of polyclonal antibodies from two species, providing a wide repertoire of antibodies against multiple N protein epitopes. Moreover, the fast, simple, and inexpensive production of polyclonal antibodies, as the most expensive assay components, would result in affordable antigen tests

Towards a dynamic earthquake risk framework for Switzerland

Scientists from different disciplines at ETH Zurich are developing a dynamic, harmonised, and user-centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue generated by the Swiss Seismological Service (SED) using the national seismic networks. This framework uses all available information to assess seismic risk at various stages and facilitates widespread dissemination and communication of the resulting information. Earthquake risk products and services include operational earthquake (loss) forecasting (OE(L)F), earthquake early warning (EEW), ShakeMaps, rapid impact assessment (RIA), structural health monitoring (SHM), and recovery and rebuilding efforts (RRE). Standardisation of products and workflows across various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access the same databases, workflows, and software is a crucial component. A user-centred approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a significant innovation featured in all products and services. Here we report on the key considerations and developments of the framework and its components. This paper may serve as a reference guide for other countries wishing to establish similar services for seismic risk reduction.</p

Combinatorial hopf algebras

Над многим класама комбинаторних објеката природно се могу увести множење и комножење који задају структуру Хопфове алгебре. Позна- те су Хопфове алгебре посета, пермутација, дрвета, графова и друге. Многе класичне комбинаторне инваријанте, као џто су Мебијусова функција посета, хроматски полином графа, Ден-Сомервилове релације, изводе се из одговарајуће Хопфове алгебре. Теорију комбинаторних Хопфових алгебри засновали су Агиар, Бергерон и Сотил у раду из 2003. године. Терминални објекти у категорији комбинаторних Хопфо- вих алгебри су алгебре квазисиметричних и симетричних функција. Ове функције се појављују као функције генератрисе у комбинаторици. Предмет изучавања ове дисертације је комбинаторна Хопфова алге- бра хиперграфова и њене подалгебре градивних скупова и клатера. Ове алгебре појављују се у различитим комбинаторним проблемима, као што су бојења хиперграфова, партиције симплицијалних комплекса и комби- наторика простих политопа. Изведене су структурне везе између ових алгебри, као и њихових непарних подалгебри. Применом теорије кара- ктера дат је један метод за добијање интересантних нумеричких иденти- тета. Уопштене Ден-Сомервилове релације за застава ф-векторе Ојлерових посета доказали су Бајер и Биљера. Ове релације дефинисане су у свакој комбинаторној Хопфовој алгебри и одређују њену непарну подал- гебру. У дисертацији се решавају уопштене Ден-Сомервилове једначине за комбинаторну Хопфову алгебру хиперграфова. По аналогији са Роти- ном Хопфовом алгебром посета, дефинише се Ојлерова подалгебра Хоп- фове алгебре хиперграфова. Добијена је комбинаторна карактеризација Ојлерових хиперграфова, која зависи од нерва припадајућег клатера. На тај начин добијена је једна класа решења Ден-Сомервилових релација за хиперграфове. Ови резултати примењени су на Хопфову алгебру сим- плицијалних комплекса.Multiplication and comultiplication, which dene the structure of a Hopf algebra, can naturally be introduced over many classes of combinatorial objects. Among such Hopf algebras are well-known examples of Hopf algebras of posets, permutations, trees, graphs. Many classical combinatorial invariants, such as M obius function of poset, the chromatic polynomial of graphs, the generalized Dehn-Sommerville relations and other, are derived from the corresponding Hopf algebra. Theory of combinatorial Hopf algebras is developed by Aguiar, Bergerone and Sottille in the paper from 2003. The terminal objects in the category of combinatorial Hopf algebras are algebras of quasisymmetric and symmetric functions. These functions appear as generating functions in combinatorics. The subject of study in this thesis is the combinatorial Hopf algebra of hypergraphs and its subalgebras of building sets and clutters. These algebras appear in dierent combinatorial problems, such as colorings of hypergraphs, partitions of simplicial complexes and combinatorics of simple polytopes. The structural connections among these algebras and among their odd subalgebras are derived. By applying the character theory, a method for obtaining interesting numerical identities is presented. The generalized Dehn-Sommerville relations for ag f-vectors of eulerian posets are proven by Bayer and Billera. These relations are dened in an arbitrary combinatorial Hopf algebra and they determine its odd subalgebra. In this thesis, the generalized Dehn-Sommerville relations for the combinatorial Hopf algebra of hypergraphs are solved. By analogy with Rota's Hopf algebra of posets, the eulerian subalgebra of the Hopf algebra of hypergraphs is dened. The combinatorial characterization of eulerian hypergraphs, which depends on the nerve of the underlying clutter, is obtained. In this way we obtain a class of solutions of the generalized Dehn-Sommerviller relations for hypergraphs. These results are applied on the Hopf algebra of simplicial complexes