Influence of temperature on biogas production from fermentation residues

Fermentační zbytek z bioplynové stanice má potenciál ke zbytkové produkci bioplynu. Bylo provedeno testování této produkce bioplynu a metanu s dobou testování 180 dní při teplotách 41 oC, 27 oC a 16 oC. Nejvíce bioplynu bylo vyprodukováno vzorkem A při teplotním režimu 41 oC, a sice 152.9 ⨯ 10-3 m3.kg-1. U metanu stejný vzorek vyprodukoval při 41 oC až 86,4 ⨯ 10-3 m3 . kg-1. Statisticky významný rozdíl byl shledán mezi měrnou produkcí bioplynu i metanu všech variant testu. Dále byla produkce bioplynu a metanu v závislosti na teplotě proložena polynomem druhého stupně. Rovnice polynomu pro bioplyn můžeme napsat ve tvaru Y = (-42,927 +- 38,349) + (5,223 +- 2,9566) . X + (-0,0181 +- 0,0510) . X2, (R2 = 0,957) a pro metan Y = (-26,85 +- 27,94) + (2,3296 +- 2,1541) . X + (0,0033 +- 0,0372) . X2, (R2 = 0,939). Tyto rovnice umožňují následné určování případů zastřešení a vytápění konkrétních uskladňovacích jímek na fermentační zbytek s ohledem na dobu trvání testu 180 dní. Teoretická produkce elektrické energie kogenerační jednotou při využití průměrné produkce metanu za 180 dní testu, vzniklého při 41 oC je 70 685,0 kWh.The fermentation residue from the biogas plant has the potential for residual biogas production. This biogas and methane production was tested during 180 days at 41 oC, 27 oC and 16 oC. Most of the biogas was produced by sample A with temperature regime of 41 oC, where the specific productionof this sample was 152.9 ⨯ 10-3 m3 . kg-1. The same sample produced at 41 oC volume of 86.4 ⨯ 10-3 m3 . kg-1of methane. A statistically significant difference was found between the specific biogas and methane production of all test variants. Furthermore, the production of biogas and methane, depending on temperature, was interleaved by a second degree polynomial. The polynomial equations for biogas can be written in the form Y = (-42,927 +- 38,349) + (5,223 +- 2,9566) . X (-0,0181 +- 0,0510) . X2, (R2 = 0,957) and for methane Y = (- 26.85 +- 27.94) + (2.3296 +- 2.1541) . X (0.0033 +- 0.0372) . X2, (R2 = 0.939). These equations allow the subsequent determination of cases of roofing and heating of specific storage wells to the fermentation residue with respect to the test duration of 180 days. The theoretical electricity production by the cogeneration unit using the average methane production for 180 days of the test, generated at 41 oC, overall 70 685.0 kWh.O

Design Philosophy Study on CFRP RC Structures

The present dissertation was developed with the main purpose of comparing the different design philosophies existing for prestressed reinforced concrete members, as well as analyzing a solution that is both safe and economically viable. Since one of the major problems in civil engineering infrastructures is due to corrosion, a study was conducted to examine the feasibility of replacing the material used as reinforcement and prestress. The steel, which for many decades has been used shall be replaced by FRP, particularly CFRP. However, since carbon presents a brittle behavior, a new design methodology suggested by fib and by the Canadian code is presented so that the failure is not due to the reinforcement but due to the concrete, which, although it is not a ductile material, presents more ductility than materials with carbon fibers. In this way, a code has been developed so that, through the balance of the cross section, it calculates the amount of reinforcement required, following the American (ACI) and European code (Eurocode) design methodology. Another code for prestressed reinforced concrete members was elaborated to analyze the prestress system used and the material used as reinforcement and tendons. The European code has proved to be economically viable since, for the same applied moment, it requires a smaller amount of reinforcement. As for the bonded and unbonded system the results show that the systems with unbonded tendons are only feasible when the concrete members are subjected to high moments. It is also observed that depending on the initial force applied on the prestress, the results may be favorable regarding to the amount of reinforcement required, however the amount of reinforcement can be significantly increased when the initial force of the prestress is highly increased

Concentration variability of water-soluble ions during the acceptable and exceeded pollution in an industrial region

This study investigates the chemical composition of water-soluble inorganic ions at eight localities situated in the Moravian-Silesian Region (the Czech Republic) at the border with Poland. Water-soluble inorganic ions were monitored in the winter period of 2018 (January, 11 days and February, 5 days). The set was divided into two periods: the acceptable period (the 24-h concentration of PM10 50 mu g/m(3)). Air quality in the Moravian-Silesian Region and Upper Silesia is among the most polluted in Europe, especially in the winter season when the concentration of PM10 is repeatedly exceeded. The information on the occurrence and behaviour of water-soluble inorganic ions in the air during the smog episodes in Europe is insufficient. The concentrations of water-soluble ions (chlorides, sulphates, nitrates, ammonium ions, potassium) during the exceeded period are higher by two to three times compared with the acceptable period. The major anions for both acceptable period and exceeded pollution are nitrates. During the period of exceeded pollution, percentages of water-soluble ions in PM10 decrease while percentages of carbonaceous matter and insoluble particles (fly ash) increase.Web of Science1710art. no. 344

Análisis numérico del comportamiento de elementos continuos pretensados con tendones de polímeros reforzados con fibras (FRP)

L'estudi de nous materials al món de la construcció és un símptoma d'avenç i millora de les tècniques de disseny i construcció actuals. Un procés natural que amb el pas del temps va experimentant amb models numèrics o campanyes experimentals, amb la finalitat d'obtenir uns resultats prou bons, com per arribar en un futur a recollir aquesta innovació en una normativa mundialment reconeguda amb uns estàndards de càlcul i disseny . Una de les problemàtiques més grans de les estructures de formigó armat i pretesat és la corrosió de les seves armadures. En estructures pretesades, la corrosió sota el efectes de la tensió és especialment preocupant ja que pot provocar el col·lapse de les estructures. Des de començaments d'aquest segle, s'han començat a introduir els polímers reforçats amb fibres (FRP) al camp de la construcció com a alternativa a l'acer d'armar. Durant el desenvolupament d'aquest treball s'ha fet una investigació bibliogràfica, recollint dades des de 1992 sobre campanyes experimentals i altres estudis d'elements de FRP en forma de cable o barra utilitzats com a armadura activa i/o passiva, estudiant quins van ser els seus inicis i quines han estat les estructures projectades amb aquest tipus de sistema. Aquest treball està emmarcat en un projecte de recerca anomenat Straduravius, on s'estan estudiant les diferents propietats i/o característiques de les armadures de polímers reforçats amb fibres sota diferents tipus de sol·licitacions. Longitud d'ancoratge, adherència o comportament estructural son alguns dels conceptes que s’han anat avaluant. La metodologia de treball seguida s’ha basat en el programa de càlcul d’elements finits Abaqus, gràcies al qual s’ha aconseguit fer una modelació de les diferents situacions de càrrega que es donaran. Pretesat dels cables CFRP de les bigues a les instal·lacions d'Alvipré, transport d'aquestes fins al laboratori de la UPC, formigonat de la llosa superior i aplicació de la càrrega, en aquest cas puntual, i sota la qual s'ha de donar el col·lapse de l'estructura de la passarel·la composta. Amb el model realitzat obtindrem una predicció, que serà molt semblant a la realitat, ja que es definiran les condicions de contorn de la millor manera possible per tenir un comportament paral·lel al cas real. Aquesta predicció ens proporcionarà les reaccions en els suports, la deformada en tots els punts de la passarel·la, les tensions, tant de compressió com de tracció, al formigó i als cables, i ens permetrà avaluar la càrrega de fallada i el motiu per el qual es produeix el col·lapse de l'estructura. Amb aquestes dades també podrem fer una comparació amb els valors teòrics utilitzats per fer el dimensionament del tesat dels cables de polímers reforçats amb fibres de carboni i des de les diferents fases de construcció de la passarel·la en qüestió. El punt i final, i la valoració dels resultats obtinguts en aquesta tesi, es donarà a finals de juliol de 2023 amb l'assaig d'una passarel·la escala 1/3 a les instal·lacions de la Universitat Politècnica de Catalunya sota la supervisió dels coordinadors a càrrec del projecte i de els tècnics de laboratori.The study of new materials in the world of construction is a symptom of the progress and improvement of current design and construction techniques. A natural process that over time is experimenting with numerical models or experimental campaigns in order to obtain sufficiently good results and collect them into a globally recognized standard with standards of calculation and design. One of the biggest problems of reinforced and prestressed concrete structures is the corrosion of their reinforcement. In prestressed structures, corrosion in stress situations is particularly worrying as it can cause the collapse of the structures. Since the beginning of this century, fibre reinforced polymers (FRP) have been introduced into the construction field as an alternative to reinforced steel. During the development of this work, a bibliographic investigation has been made, collecting data from experimental campaigns and other studies of elements of FRP in the form of cable or bar used as active and/or passive reinforcement since 1992, studying which was the beginning of this process and which have been the structures projected with this type of system. This work is part of a research project called Straduravius, which is studying the different properties and characteristics of fibre reinforced polymer reinforcements under different types of stresses. Anchor length, adhesion, or structural behaviour are some concepts that have been evaluated. The methodology followed has been based on Abaqus, a finite element calculation program, thanks to that it has been possible to model the different load situations that will occur. Pre- tensioning of CFRP cables of the four beams in the Alvipré facilities, transport of these to the UPC laboratory, concreting of the upper slab and application of the concentred load, in this case, and under which the structure of the composite pedestrian bridge must collapse. With the modelling carried out, we will obtain a prediction, which will be very similar to reality, because the boundary conditions will be defined in the best way to have a behaviour parallel to the real case. This prediction will give us the reactions at the supports, the deformed at all points of the structure, the stresses, both compression and traction, in the concrete and in the cables, and allow us to assess the fault load and the reason of the structure collapse. With this data we can also make a comparison with the theoretical values used to make the sizing of the tensioning of carbon fibre reinforced polymer cables and the different phases of construction of the bridge in question. The culmination and evaluation of the results obtained in this thesis will be given at the end of July 2023 with the trial of a 1/3 scale structure in the facilities of the Universitat Politècnica de Catalunya under the supervision of the coordinators in charge of the project and the laboratory technicians.El estudio de nuevos materiales en el mundo de la construcción es un síntoma de avance y mejora de las técnicas de proyección y construcción actuales. Un proceso natural que con el paso del tiempo va experimentando con modelos numéricos o campañas experimentales, con la finalidad de obtener unos resultados suficientemente buenos, como para en un futuro llegar a recoger esta innovación en una normativa mundialmente reconocida con unos estándares de cálculo y diseño. Una de las mayores problemáticas de las estructuras de hormigón armado y pretensado es la corrosión de sus armaduras. En estructuras pretensadas, la corrosión bajo tensión es especialmente preocupante pues puede provocar el colapso de las estructuras. Desde inicios de este siglo, se han empezado a introducir los polímeros reforzados con fibras (FRP) en el campo de la construcción como alternativa al acero de armar. Durante el desarrollo de este trabajo se ha hecho una investigación bibliográfica, recogiendo datos desde 1992 sobre campañas experimentales y otros estudios de elementos de FRP en forma de cable o de barra utilizados como armadura activa y/o pasiva, estudiando cuales fueron los inicios de este proceso y cuáles han sido las estructuras proyectadas con este tipo de sistema. Este trabajo está enmarcado en un proyecto de investigación llamado Straduravius, en el cual se están estudiando las diferentes propiedades y/o características de las armaduras de polímeros reforzadas con fibras bajo diferentes tipos de solicitaciones. Longitud de anclaje, adherencia o comportamiento estructural son algunos de los conceptos que se han ido evaluando. La metodología de trabajo seguida se ha basado en el programa de cálculo de elementos finitos Abaqus, gracias al cual se ha conseguido hacer una modelación de las diferentes situaciones de carga que se darán. Pretensado de los cables CFRP de las vigas en las instalaciones de Alvipré, transporte de estas hasta el laboratorio de la UPC, hormigonado de la losa superior y aplicación de la carga, en este caso puntual, y bajo la cual se debe dar el colapso de la estructura de la pasarela compuesta. Con el modelado realizado vamos a obtener una predicción, que va a ser muy parecida a la realidad, pues se definirán las condiciones de contorno de la mejor manera para tener un comportamiento paralelo al caso real. Esta predicción nos proporcionará las reacciones en los apoyos, la deformada en todos los puntos de la pasarela, las tensiones, tanto de compresión como de tracción, en el hormigón y en los cables, y nos permitirá evaluar la carga de fallo y el motivo por el cual se produce el colapso de la estructura. Con estos datos también podremos hacer una comparación con los valores teóricos utilizados para realizar el dimensionamiento del tesado de los cables de polímeros reforzados con fibras de carbono y desde las diferentes fases de construcción de la pasarela en cuestión. La culminación y valoración de los resultados obtenidos en esta tesis se dará a finales de Julio de 2023 con el ensayo de una pasarela escala 1/3 en las instalaciones de la Universitat Politècnica de Catalunya bajo la supervisión de los coordinadores a cargo del proyecto y de los técnicos de laboratorio

Development of analytical model for bonding of CFRP rod in concrete subjected to cyclic loads

Recent material science advances have resulted in the use of High-Performance Concrete (HPC) and Ultra-High-Performance Concrete (UHPC) in superstructures, which were chosen for their superior strength. However, under cyclic loads, these materials frequently show fatigue. Carbon-Fibre-Reinforced Polymer (CFRP) rods are replacing steel rebars due to their corrosion resistance and excellent strength-to-weight ratio and are thus gaining popularity in both infrastructural and superstructural design. However, due to a lack of understanding of their bond mechanics, modelling the interaction between CFRP rods and these advanced concretes in finite element simulations remains complex, particularly under cyclic loading. The bond behaviour of CFRP rods and both standard Grade 40 concrete and Ultra High-Performance Fibre-Reinforced Concrete (UHPFRC) under cyclic stresses is investigated in this work. A finite element model of connected concrete cube samples was built and analysed under cyclic stress, combining these concretes with CFRP rods. Furthermore, these samples were subjected to dynamic actuation testing to develop a traction-based constitutive model for the CFRP–concrete interface. In finite element models, an interface element devised for this study effectively approximated the binding, matching experimental data. The new analytical interface element improved simulation precision by 19% in displacement and 49% in pull-out force, resulting in a significant improvement in predicting the performance of the CFRP–UHPFRC bond under cyclic loading. The improved performance of the CFRP–UHPFRC bond under cyclic loading is attributed to the optimised interface model that enhances the bond integrity between CFRP rods and concrete

Strengthening historic covered bridges to carry modern traffic

The focus of this study was to develop means and methods to strengthen timber superstructural components of historic covered bridges using Glass Fiber Reinforced Polymer (GFRP) composite materials. The strengthening methodologies developed during this research project were designed to conform to the Secretary of the Interior\u27s Standards for the Treatment of Historic Properties. More specifically, tension and bending tests were conducted to establish bond strength of GFRP rebars embedded in wood, and to establish bending strength and stiffness of large-scale beams reinforced with GFRP pultruded plates, and GFRP rebars. The GFRP rebars were developed to be used specifically as reinforcing materials for truss members, while the GFRP plates were developed to enhance the bending capacity of floor beams and stringers. The results showed bonded-in GFRP rebars performed very well in terms of pullout force and bond strength, and the strength and stiffness of GFRP reinforced timber beams improved significantly. Additionally, during this research several methods of concealing the reinforcement, thereby preserving the historic integrity of structural members were investigated

The possibilities of biomakers utilisation for pollution sources identification

Predložená dizertačná práca rieši možnosť identifikácie a kvantifikácie energetických zdrojov použitím navrhnutého klasifikačného nástroja, ktorý umožňuje redukovať celkové množstvo organických zlúčenín identifikovaných vo vzorkách a extrahovať len tie najdôležitejšie markery pre vybrané energetické zdroje sledovaných oblastí. Na základe selektovaných markerov bol následne identifikovaný podiel spaľovaného paliva na znečistení ovzdušia. Teoretická časť je venovaná charakteristike špecifických organických látok – tzv. markerom, ktoré sú charakteristické pre jednotlivé energetické zdroje znečistenia, resp. typ spaľovaného paliva. Konkrétne sú predstavené markery pre spaľovanie biomasy, uhlia, plastov a markery uvoľňované z dieselových a benzínových motorových vozidiel. Ďalej sú popísané najpoužívanejšie modely na identifikáciu a kvantifikáciu energetických zdrojov na znečistení ovzdušia, ich výhody a úskalia. Jednotlivé kroky navrhnutého modelu sú detailne popísaný v metodike práce, vrátane obhájenia jeho matematickej správnosti. Navrhnutý model bol aplikovaný v dvoch meracích kampaniach na území malej mierky (Napajedla) a veľkej mierky (Moravsko-sliezsky kraj). V rámci meracej kampane realizovanej v meste Napajedla bolo testované, či je možné sa v štúdiách na identifikáciu zdrojov zamerať sa len na vybrané prominentné markery, čo by mohlo v budúcnosti uľahčiť časovo náročné analytické metódy. Daná metóda sa ukázala byť spoľahlivá pre oblasť malej mierky. Dokonca použitie len vybraných markerov v mnohorozmerných metódach umožnilo rozlíšiť zdroje medzi jednotlivými odberovými miestami presnejšie než použitím všetkých analyzovaných zlúčenín. V rámci meracej kampane realizovanej na území MSK bolo zisťované, ktoré z energetických zdrojov sa podieľajú na zhoršenej kvalite ovzdušia zimnom období najvýznamnejšie, pričom pozornosť bola upriamená na smogovú situáciu. Na území MSK sa stretávame s úskalím veľkej rozmanitosti identifikovaných organických látok naprieč odberovými lokalitami, preto bolo nutné dáta vhodným spôsobom zjednotiť na vyťaženie čo najrelevantnejšieho výsledku s čo najmenšou stratou informácie. Výsledky ukázali, že každá odberová lokalita je špecifická iným prevládajúcim zdrojom znečistenia, niektoré lokality si však boli prevládajúcimi zdrojmi podobné. Pri rozdelení do klastrov bola počas smogovej situácie najvýznamnejší faktor lokalita, u nesmogovej situácie bol najvýznamnejší faktor deň odberu. Najviac špecifické lokality počas smogovej aj nesmogovej sezóny sa ukázali lokality Poruba a Radvanice, čo naznačuje, že dané lokality sú ovplyvnené stálymi lokálnymi zdrojmi, na ktoré nemá až taký významný vplyv napr. zmena prúdenia vetra.The presented dissertation thesis deals with the possibilities of the identification and quantification of the energy pollution sources using the proposed classification tool allowing the reduction of the total amount of the organic compounds identified in the samples and extraction only of the most important markers of the selected energy pollution sources in the sites of interest. Based on the selected markers, the influence of the fuel combustion on the air pollution is identified. The theoretical part is focused on the characterization of specific organic compounds – markers, which are characteristic for the particular energy pollution sources, namely the type of the fuel combusted. Specifically, the markers for biomass, coal and plastics burning and markers released from diesel and petrol engine vehicles. The most commonly used models for source apportionment of energy air pollution sources are also described, mentioning their particular advantages and disadvantages. The individual steps of the proposed model are described in the Methods section of the thesis including the justification of its mathematical soundness. The proposed model was applied in two measurement campaigns performed in a small-scale area (Napajedla) and large-scale area (Moravian-Silesian region). During the Napajedla measurement campaign, the possibility of focusing only on the prominent markers in the source apportionment studies was tested which would, in future, lead to facilitation of the time-consuming analytical techniques. The method was found to be reliable for the small-scale area. Moreover, using only the selected markers in the multivariate methods allowed the distinction of the pollution sources between the individual sites even more accurately than using all the determined compounds. During the Moravian-Silesian region campaign, identification of the most important energy pollution sources during the winter period of worsened air conditions was the main goal while the study was focused on the smog situation. High diversity of the identified organic markers in the PM10 samples between the individual sampling sites was to be addressed in this campaign, hence, the data had to be unified to extract as complete dataset as possible – with losing a minimal information. The results shown that each sampling site is specific by different prevalent source of pollution, some were, however, similar. In the cluster partitioning, the factor of site was found to be the most important during the smog season, whereas during the non-smog season, the sampling day was the most important factor. The most specific sites during both seasons were sites Poruba and Radvanice indicating that these sites are influenced by stable local sources and are not significantly influenced by e.g. change in wind direction.361 - Katedra energetikyvyhově

Dermatological manifestations of infection by Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum

Lymeská borrelióza (LB) a lidská granulocytární anaplasmóza (LGA) patří mezi antropozoonózy, které se vyskytují ve stejných geografických oblastech a na člověka jsou přenášeny stejným druhem klíštěte rodu Ixodes. Zatímco patogenem LB je extracelulární spirochéta Borrelia burgdorferi a symptomy, průběh, diagnostika a léčba onemocnění je dobře známá, LGA patří mezi nová a méně známá onemocnění. LGA způsobuje obligátní intracelulární bakterie Anaplasma phagocytophilum a onemocnění probíhá nejčastěji jako horečnaté onemocnění doprovázené dalšími nespecifickými příznaky, mezi které patří třesavka, únava, bolesti svalů, kloubů a hlavy. V průběhu neléčené infekce může dojít k orgánovému postižení, zejména respiračního systému, gastrointestinálního traktu a nervového systému. Mezi laboratorní známky infekce patří změny v krevním obrazu - leukopenie, anémie, trombocytopenie, a elevace jaterních enzymů. V Severní Americe se vyskytuje větší počet symptomatických a závažných případů, které mohou mít ve výjimečných případech i fatální průběh. V Evropě jsou průběhy LGA mírné až asymptomatické. Promořenost klíšťat anaplasmovou DNA v Evropě je vysoká, vysoká je i prevalence anaplasmových protilátek u divokých zvířat. Séroprevalence zejména v rizikové populaci je u nás i v Evropě vysoká. V souvislosti s LB můžeme...Lyme disease (LD) and human granulocytic anaplasmosis (HGA) are anthropozoonoses that occur in the same geographical areas and are transmitted to humans by the same species of ticks of the genus Ixodes. While the extracellular pathogen of LD, spirochete Borrelia burgdorferi, and symptoms, course, diagnosis and treatment of the disease are well known, the HGA is one of the new and less known diseases. HGA is caused by an obligate intracellular bacterium Anaplasma phagocytophilum and the disease most often presents as a febrile illness accompanied by other nonspecific symptoms, including chills, fatigue, muscle pain, joint pain and headaches. An untreated infection can cause organ involvement, particularly of respiratory, gastrointestinal and the nervous system. Laboratory signs of infection include changes in the blood count - leucopenia, anemia, thrombocytopenia, and elevated liver enzymes. Among cases reported from North America , there is a higher portion of symptomatic and severe cases,, with some reported deaths. In Europe, the course of HGA tends to be mild or asymptomatic. The percentage of ticks containing anaplasma DNA in Europe is high, there is also a high prevalence of anaplasma antibodies in wild animals. Seroprevalence especially in the high-risk population in our country and in Europe is high....Dermatovenerologická klinikaDepartment of Dermatology2. lékařská fakultaSecond Faculty of Medicin