57 research outputs found
Der Christ, der aus der Liebe für die Liebe lebt
Der Artikel behandelt das zweifache Liebesgebot: die Liebe zu Gott und die Liebe zu den Nächsten, nach 1 Kor 13 und 1. Johannesgrief
The ascetic science of Benedikt Rogačić
This article is a brief presentation of the life and works of the esteemed Jesuit from Dubrovnik, Benedikt Rogacic (1646-1719). Aside from priestly and pedagogic activities. Rogacic was the author of a number of works in Italian and Latin, including a successful Italian grammar, extensive poetry and the lengthy "Dell\u27Uno Necessario" containing a wealth of scholastic analyses and psychological observations as well as religious writings, history and above all a mystical ecstatic relationship with God. Halamhek is of the opinion that such a work deserves to have been made a required aesthetic text, imbued as if is with a sense of the suprnatural, joy, optimism, in addition to all the seriousness and rigorousness of Christian aspiration toward sanctification
Bilinearne i kvadratne forme
Tri su glavna tipa bilinearnih formi: simetrične, unitarne i alternirajuće. U ovom diplomskom radu dajemo strukturne teoreme o matričnim prikazima ovih formi s obzirom na odgovarajuće baze. Rad između ostalog, prati standardni postupak rastava objekata na direktnu sumu prostih objekata, koliko je to moguće. Nakon prvog poglavlja, u kojem su definirani osnovni pojmovi potrebni za razumijevanje daljnjeg sadržaja rada, slijedi drugo poglavlje koje je podijeljeno u jedanaest potpoglavlja. Pobliže promatramo bilinearna te kvadratna preslikavanja, a također i bilinearne i kvadratne forme. Dokazujemo također i egzistenciju ortogonalne baze za simetrične bilinearne forme te donosimo dijagonalni prikaz te forme. Zatim promatramo simetrične bilinearne forme definirane nad uređenim poljem te iskazujemo i dokazujemo Sylvesterov teorem te opisujemo induktivni postupak, Gram-Schmidtov postupak ortogonalizacije. Donosimo i dokaz egzistencije ortogonalne baze za vektorski prostor na kojem je definirana hermitska forma, a nakon toga slijede spektralni teoremi, u hermitskom, unitarnom te simetričnom slučaju. Slijede alternirajuće bilinearne forme te uvođenje definicija hiperboličke ravnine te hiperboličkog prostora. Na kraju, iskazujemo te dokazujemo Wittov teorem te definiramo pojam Wittove grupe.There are three major types of bilinear forms: symmetric, unitary, and alternating. In this diploma thesis, we present structural theorems giving normalized expressions for these forms with respect to suitable bases. We follow the standard pattern of decomposing an object into a direct sum of simple objects, insofar as possible. After the first chapter, in which the basic concepts necessary to understand the further contents of the work were defined, follows the second chapter which is divided into eleven subsections. We closely study bilinear and quadratic maps and also bilinear and quadratic forms. We also prove the existence of orthogonal basis for symmetric bilinear forms and present the diagonal representation of this form. Furthermore, we study bilinear symmetric forms defined on an ordered field, we state and prove Sylvester theorem and we describe the inductive process, Gram-Schmidt orthogonalization process. We present the proof of existence of orthogonal basis for a vector space in which the hermitian form is defined, followed by spectral theorems, in hermitian, unitary and symmetric cases. After that we study alternating bilinear forms and define hyperbolic plane and hyperbolic space. Finally, we state the Witt theorem and define the concept of Witt group
Titanium Ions Release from an Innovative Titanium-Magnesium Composite: an in Vitro Study
Svrha: U ovom radu istraživala su se korozijska svojstva inovativnog titanij-magnezijeva (Ti-Mg) kompozita proizvedenog metodom metalurgije praha (P/M). Materijal i metode: Ispitivane su dvije grupe
eksperimentalnog materijala – s 1 masenim udjelom (mass% Ti-1Mg) i 2 masena udjela (mass% Ti-2Mg) magnezija u titanijskoj osnovi te su uspoređene s komercijalno čistim titanijem (CP Ti). Test uranjanja i kemijska analiza četiriju otopina: umjetne sline, umjetne sline pH 4, umjetne sline s dodatkom fluora i Hankove otopine, provedeni su nakon 42 dana uranjanja metodom masene spektrometrije induktivno spregnutom plazmom (ICP – MS) kako bi se ustanovila količina otpuštenih iona titanija (Ti). Za određivanje svojstava površine korištene su analize SEM i EDS. Rezultati: Razlika u rezultatima između različitih ispitivanih otopina procjenjivana je ANOVA-om i Newman-Keulsovim testom na razini značajnosti od p < 0,05. Utjecaj prediktorskih varijabli utvrđivan je multiplom regresijskom analizom. Rezultati ovog istraživanja pokazuju nisku stopu korozije titanija u ispitivanoj skupini Ti-Mg. Uočeno je do 46 puta, odnosno 23 puta manje otapanje iona titanija iz Ti-1Mg i Ti-2Mg u usporedbi s kontrolnom skupinom. Između ispitivanih otopina, umjetna slina s dodatkom fluora pokazala je najveći korozijski učinak među svim ispitivanim uzorcima. SEM-analiza pokazala je sačuvanu dvofaznu strukturu površine, a EDS-analiza upozorila je na moguća bioaktivna svojstva površine. Zaključak: Ti-Mg kompozit proizveden metodom P/M-a sugerira se kao materijal boljih korozijskih svojstava u usporedbi s čistim titanijem (CP Ti).The innovative titanium-magnesium composite (Ti-Mg) was produced by powder metallurgy (P/M) method and is characterized in terms of corrosion behavior. Material and methods: Two groups of experimental material, 1 mass% (Ti-1Mg) and 2 mass% (Ti-2Mg) of magnesium in titanium matrix, were tested and compared to commercially pure titanium (CP Ti). Immersion test and chemical analysis of four solutions: artificial saliva; artificial saliva pH 4; artificial saliva with fluoride and Hank balanced salt solution were performed after 42 days of immersion, using inductively coupled plasma mass spectrometry (ICP-MS) to detect the amount of released titanium ions (Ti). SEM and EDS analysis were used for surface characterization. Results: The difference between the results from different test solutions was assessed by ANOVA and Newman-Keuls test at p<0.05. The influence of predictor variables was found by multiple regression analysis. The results of the present study revealed a low corrosion rate of titanium from the experimental Ti-Mg group. Up to 46 and 23 times lower dissolution of Ti from Ti-1Mg and Ti-2Mg, respectively was observed compared to the control group. Among the tested solutions, artificial saliva with fluorides exhibited the highest corrosion effect on all specimens tested. SEM micrographs showed preserved dual phase surface structure and EDS analysis suggested a favorable surface bioactivity. Conclusion: In conclusion, Ti-Mg produced by P/M as a material with better corrosion properties when compared to CP Ti is suggested
Physicochemical Properties, Cytotoxicity, and Antioxidative Activity of Natural Deep Eutectic Solvents Containing Organic Acid
Natural deep eutectic solvents (NADES) may be considered ‘designer solvents’ due to their numerous structural variations and the possibility of tailoring their physicochemical properties. Prior to their industrial application, characterization of NADES is essential, including determination of their physicochemical properties, cytotoxicity, and antioxidative activity. The most important physicochemical properties of eight prepared NADES (choline chloride:malic acid, proline:malic acid, choline chloride:proline:malic acid, betaine:malic acid, malic acid:glucose, malic acid:glucose:glycerol, choline chloride:citric acid, and betaine:citric acid) were measured as functions of temperature and water content. In general, the structure of prepared NADES greatly influences their physical properties, which could be successfully modified and adjusted by addition of water. All tested NADES were absolutely benign and noncorrosive for investigated steel X6CrNiTi18-10. Furthermore, cytotoxicity of prepared solvents was assessed toward three human cell lines (HEK-293T, HeLa, and MCF-7 cells), and antioxidative activity was measured by the Oxygen Radical Absorbance Capacity (ORAC) method. With regard to cell viability, all tested NADES containing carboxylic acid could be classified as practically harmless and considered environmentally safe. The ORAC values indicated that the tested NADES displayed antioxidative activity
Potentiodynamic polarization studies of Cefadroxil and Dicloxacillin drugs on the corrosion susceptibility of aluminium AA6063 in 0.5 M nitric acid
The inhibition effectiveness of Cefadroxil (C) and Dicloxacillin (D) drugs on aluminium in0.5 M nitric acid solution have been holistically studied using potentiodynamic polarizationtechniques, weight loss measurements, computational studies and structural character-ization. The structural characterizations were carried with the aid of scanning electronmicroscope equipped with energy dispersive spectrometer (SEM/EDS), optical microscope(OPM) and XRD. Potentiodynamic polarization test revealed the corrosion protectivenessand adsorbing ability of Cefadroxil and Dicloxacillin drugs on aluminium (Al). The mixedinhibitive characteristics of Cefadroxil and Dicloxacillin drugs were confirmed through theTafel plot, which further established their predominant effect on the anodic reaction asa result of Ecorrvalue shift to more positive sides. The combined effect of Cefadroxil andDicloxacillin drugs reduced the exchange in current density and corrosion rate drasticallyfrom 484 �A/cm2to 199 �A/cm2and 0.4502 mm/year to 0.2152 mm/year respectively. 44.4%increase in microhardness was achieved and Inhibition efficiency of 58.9% was accom-plished
Corrosion Protection Effect of Chitosan on the Performance Characteristics of A6063 Alloy
This article outlines the behaviour of water-soluble chitosan as an effective inhibitor on aluminium alloy in 3.65% NaCl at room temperature. The inhibitive ability of water-soluble chitosan was examined using electrochemical potentiodynamic polarization techniques, mass loss measurements and computational studies. The outcome of the experiment reveals that chitosan inhibited aluminium alloy in sodium chloride solution exhibits better corrosion protection than the uninhibited because chitosan nanoparticles minimize the ingression of chloride ion into the active sites of aluminium alloy by forming thin film on its surface. The losses in mass by the inhibited aluminium alloy were found to reduce as the concentration of chitosan increases. Results obtained showed that chitosan could offer inhibition efficiency above 70%. Polarization curve demonstrated that chitosan in 3.65% NaCl at room temperature acted as a mixed-type inhibitor. Adsorption of chitosan nanoparticles on the aluminium alloy was found to follow Langmuir adsorption isotherm with correlation regression coefficient (R2
) value of 0.9961
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