Toughness Behaviour in Armour Steel Welds

The process of welding armor steel is a complex process not only due to high percentage of carbon in the base metal, but also because of possible welding faults, appearing in the weld metal zone in the form of cracks and pores. Austenitic filler material is traditionally used for welding armor steels, thus avoiding the negative effect of hydrogen content due to slow diffusion towards the sensitive fusion line. For heavy structural engineering such as armored military vehicles, which are frequently under the effect of impact and dynamic load, it is important to know the dynamic properties of the most sensitive area of welded joints, the weld metal zone. Instrumented impact testing was made on Charpy V specimens. The impact energy results were 56 J and 29 J for crack initiation and propagation, respectively. Due to a significant interest in quantification of material resistance to crack initiation and propagation, the fatigue crack growth rate was measured in the welded metal zone, while the resistance to crack growth in the weld metal was tested by the amount of austenite transformed into martensite. Accordingly, the threshold stress concentration factor was 10 MPa m1/2. XRD spectral analysis revealed direct transformation of γ - austenite into α’ - martensite

Koordinacioni polimer Ag(I) sa 1,2,4,5-benzentetrakarboksilnom kiselinom i tiomorfolin-4-karbonitrilom

Metal-organic frameworks (MOFs) are regarded as promising materials for applications in catalysis, separation, gas storage and molecular recognition. Here we report the synthesis and characterization of novel silver(I) MOF obtained by the reaction of silver(I) nitrate with 1,2,4,5- benzenetetracarboxylic acid (H4BTEC) and thiomorpholine-4-carbonitrile (tmc). As shown by X-ray difraction analysis, silver(I) centers have distorted tetrahedral geometry with two coordination sites occupied by carboxylic oxygen atoms of two H4BTEC, and the other two by N-atom from nitrile group and S-atom of tmc, respectively. Adjacent silver-carboxylate chains are connected by two tmc ligands into a 2D polymeric structure. Water molecules between these 2D layers are hydrogen bonded to carboxylic groups from adjacent layers and thus expanding the 2D structure into a supramolecular 3D structure. Hydrogen bonds make this structure flexible and suitable for gas absoption. Potential aplication of this coordination polymer as a hydrogen storage material will be the subject of further investigations.Metal-organske umrežene strukture (engl. Metal organic frameworks, MOFs) predstavljaju potencijalno dobre materijale sa primenom u katalizi, odvajanju, skladištenju gasova i molekulskom prepoznavanju. U ovom radu opisana je sinteza i karakterizacija novog MOF-a srebra(I) dobijenog reakcijom srebro(I)-nitrata sa 1,2,4,5-benzentetrakarboksilnom kiselinom (H4BTEC) i tiomorfolin-4-karbonitrilom (tmc). Rendgenska strukturna analiza je pokazala da srebro(I) centri imaju distorgovanu tetraedarsku geometriju, pri čemu dva koordinaciona mesta zauzimaju atomi kiseonika dva molekula H4BTEC, dok su druga dva koordinacina mesta zauzimaju redom N-atom nitrilne grupe i S-atom tmc-a. Susedni srebro-karboksilatni lanci su povezani preko dva tmc liganda u 2D polimernu strukturu. Između 2D slojeva nalaze se molekuli vode koji grade vodonične veze sa karboksilatnim grupama iz susednih slojeva formirajući supramolekulsku 3D strukturu. Vodonične veze čine ovu strukturu fleksibilnom i pogodnom za apsorpciju gasova. Potencijalna primena ovog koordinacionog polimera za skladištenje vodonika će biti predmet daljih istraživanja

KRISTALNE STRUKTURE (2-(PIRIDIN-2-IL)-1H-INDOL- 3-IL)(3,4,5-TRIMETOKSIFENIL)-METANONA (HL) I NJEGOVIH KOMPLEKSA SA Cu(II) I Pd(II)

Novel Cu(II) and Pd(II) complexes with 2-(2’-pyridyl)-indole ligand HL, modified with 3,4,5-trimethoxybenzoyl group, were synthesized with the aim of getting biologically active transition metal complexes. The complexes were synthesized by the reaction of HL with CuCl2·2H2O and [PdCl2(CH3CN)2]. Single crystals of HL and complexes [Cu2L2Cl2(DMSO)2] and [PdL(HL)Cl] were obtained and their structures were determined by X-ray diffraction analysis. Cu(II) complex is a centrosymmetric dimer with squarepyramidal geometry around both metal centers, while Pd(II) complex has square-planar geometry. Molecular structures of HL and complexes are given in Fig. 1. Crystal packings of HL and its Pd(II) and Cu(II) complexes are based on hydrogen bonds and π–π stacking interactions. The main crystallographic data: HL, C23H20N2O4, Mr = 388.41, orthorhombic system, space group Pbca, a = 12.861(5), b = 16.810(5), c = 18.764(5) Å, V = 4057(2) Å3, Z = 8, ρ = 1.272 g cm–3, refinement on F2 (270 parameters) yielded R1 = 0.0681, wR2 = 0.1092, S = 1.040 for all data, and R1 = 0.0458 for 2629 observed reflections with I ≥ 2σ(I). [Cu2L2Cl2(DMSO)2], C25H25ClCuN2O5S, Mr = 564.52, triclinic system, space group P –1, a = 7.7503(4), b = 12.0523(7), c = 13.6355(8) Å, α = 83.347(5), β = 81.711(5), γ = 89.180(4)°, V = 1251.88(12) Å3, Z = 2, ρ = 1.498 g cm– 3, refinement on F2 (338 parameters) yielded R1 = 0.0485, wR2 = 0.0934, S = 1.053 for all data, and R1 = 0.0402 for 3839 for observed reflections with I ≥ 2σ(I). [PdL(HL)Cl], C46H39ClN4O8Pd, Mr = 917.66, monoclinic system, space group P21/n, a = 11.8254(2), b = 14.7137(2), c = 23.3483(4) Å, β = 104.498(2)°, V = 3933.13(11) Å3, Z = 4, ρ = 1.550 g cm–3, refinement on F2 (567 parameters) yielded R1 = 0.0396, wR2 = 0.0818, S = 1.051 for all data, and R1 = 0.0307 for 5884 observed reflections with I ≥ 2σ(I).Novi kompleksi Cu(II) i Pd(II) sa 2-(2’-piridil)-indolskim ligandom HL, modifikovanim dodatkom 3,4,5-trimetoksibenzoil grupe, sintetisani su sa ciljem dobijanja biološki aktivnih kompleksa prelaznih metala. Kompleksi su sintetisani reakcijom HL sa CuCl2·2H2O, odnosno [PdCl2(CH3CN)2]. HL i kompleksi [Cu2L2Cl2(DMSO)2] i [PdL(HL)Cl] su dobijeni u vidu monokristala i njihova struktura je rešena rendgenskom strukturnom analizom. Kompleks Cu(II) je centrosimetrični dimer sa kvadratno-piramidalnim okruženjem oko oba metalna centra, dok je kompleks Pd(II) kvadratno- planarne geometrije. Molekulske strukture liganda HL i kompleksa prikazane su na Slici 1. Kristalno pakovanje HL i njegovih kompleksa je zasnovano na vodoničnim vezama i π–π steking interakcijama. Osnovni kristalografski podaci: HL, C23H20N2O4, Mr = 388,41, ortorombični sistem, prostorna grupa Pbca, a = 12,861(5), b = 16,810(5), c = 18,764(5) Å, V = 4057(2) Å3, Z = 8, ρ = 1,272 g cm–3, utačnjavanje sa F2 (270 parametra) dalo je R1 = 0,0681, wR2 = 0,1092, S = 1,040 za sve podatke i R1 = 0,0458 za 2629 refleksija sa I ≥ 2σ(I). [Cu2L2Cl2(DMSO)2], C25H25ClCuN2O5S, Mr = 564,52, triklinični sistem, prostorna grupa P –1, a = 7,7503(4), b = 12,0523(7), c = 13,6355(8) Å, α = 83,347(5), β = 81,711(5), γ = 89,180(4)°, V = 1251,88(12) Å3, Z = 2, ρ = 1,498 g cm–3, utačnjavanje sa F2 (338 parametra) dalo je R1 = 0,0485, wR2 = 0,0934, S = 1,053 za sve podatke i R1 = 0,0402 za 3839 refleksija sa I ≥ 2σ(I). [PdL(HL)Cl], C46H39ClN4O8Pd, Mr = 917,66, monoklinični sistem, prostorna grupa P21/n, a = 11,8254(2), b = 14,7137(2), c = 23,3483(4) Å, β = 104,498(2)°, V = 3933,13(11) Å3, Z = 4, ρ = 1,550 g cm–3, utačnjavanje sa F2 (567 parametra) dalo je R1 = 0,0396, wR2 = 0,0818, S = 1,051 za sve podatke i R1 = 0,0307 za 5884 refleksija sa I ≥ 2σ(I)

METAL-ORGANSKE UMREŽENE STRUKTURE SREBRA(I) SA POTENCIJALNIM ANTIMIKROBNIM SVOJSTVIMA

Jedan od glavnih svetskih problema u javnom zdravlju predstavlja pojava novih otpornih sojeva mikroba. Stoga je potreba za novim antimikrobnim agesima pravi izazov. Metalorganske umrežene strukture (engl. metal-organic frameworks, MOFs) se mogu smatrati obećavajućim antimikrobnim agensima stoga što njihove neorganske i organske komponente mogu da obezbede platformu za visoku antimikrobnu aktivnost. Tokom proteklih godina, nova jedinjenja srebra, uključujući i nove materijale, su se pokazala kao snažni antimikrobni agensi [1]. Uzimajući ovo u obzir, sintetisana su četiri nova MOF-a srebra(I) sa derivatima tiomorfolina i piperazina (Shema 1) koji su okarakterisani rendgenskom strukturnom analizom. Antimikrobna aktivnost je određena na osam bakterijskih sojeva i tri soja gljivica. Kompleks 4 je pokazao dobru antimikrobnu aktivnost na svim testiranim sojevima mikroorganizama.Resistant microbial strains are continuously emerging which is one of the major worldwide public health concerns. The need for new antimicrobial agents is a real challenge. Metal-organic frameworks (MOFs) can be considered as promising antimicrobial materials because their inorganic and organic components can provide platforms to generate high potent antimicrobial activity. Over recent years, new silver compounds, including new materials, have been proposed as potent antimicrobial agents [1]. Taking this into account, four new silver-based MOFs were synthesized (Scheme 1), using thiomorpholine and piperazine derivatives as ligands, and characterized by X-ray diffraction analysis. The antimicrobial activity was evaluated on eight bacterial and three fungi strains. Complex 4 has good antimicrobial activity on all studied microorganisms

X-ray structural analysis and antitumor activity of new salicylic acid derivatives

This Thesis project is going to be situated in my home town Östersund, 600 kilometers north from Stockholm.It´s a small town with 60 000 people and it is the only city of the region Jämtland in Norrland, Sweden.In the city centre of Östersund there is one existing bus terminal station where the buses arrive with people from the entire region.The task for this Thesis project is to rebuild the existing bus station in Östersund where the actual terminal building is going to be completely demolished and the entire block within the current bus stops is going to be rearranged.The topography of the terminal area is now dividing the regional buses that arrives on the upper level from the city buses that stops at the lower level. Therefore the main challenge of the new proposal is how one would strengthen the junction between these two flows of people and how a new architecture could enable the encounter between the countryside and the urban city.Detta examensprojekt kommer att vara belägen i min hemstad Östersund, 600 kilometer norr om Stockholm. Det är en liten stad med 60 000 personer och det är den enda staden i regionen Jämtland, Norrland. I centrum av Östersund finns en befintlig bussterminalen där bussarna anländer med folk från hela regionen. Uppgiften för detta projekt är att bygga om den befintliga busstationen i Östersund topografin på terminalområdet i dagsläget separerar de regionala bussarna som anländer på den övre nivån från stadsbussarna som stannar på en lägre nivå. Den största utmaningen i det nya förslaget är hur man istället skulle kunna stärka förbindelsen mellan dessa två flöden av människor och hur en ny arkitektur kan möjliggöra mötet mellan glesbyggd och den urbana staden

Medical physics education at the University of Novi Sad - Serbia

Overview of new educational program and training in Medical Physics at the University of Novi Sad is presented, where the medical physics education from undergraduate to doctoral study is established in the last decade. Necessity for basic and additional education and hospital training for medical physicists becomes the evident subject in clinical practice in which physicists and physicians are in close collaboration to ensure high quality of patient care. Learning objectives: to incorporate the latest scientific and professional findings in the field of medical physics, medical diagnostics, therapy and instruments; to accomodate students pursuits of individual fields by offering elective courses from different areas of current medical practice; to reflect the multidisciplinary spirit of the studies, since teaching is performed by experts from diverse fields.6th International Conference of the Balkan-Physical-Union, Aug 22-26, 2006, Istanbul, Turke

Medical physics education at the University of Novi Sad - Serbia

Overview of new educational program and training in Medical Physics at the University of Novi Sad is presented, where the medical physics education from undergraduate to doctoral study is established in the last decade. Necessity for basic and additional education and hospital training for medical physicists becomes the evident subject in clinical practice in which physicists and physicians are in close collaboration to ensure high quality of patient care. Learning objectives: to incorporate the latest scientific and professional findings in the field of medical physics, medical diagnostics, therapy and instruments; to accomodate students pursuits of individual fields by offering elective courses from different areas of current medical practice; to reflect the multidisciplinary spirit of the studies, since teaching is performed by experts from diverse fields.6th International Conference of the Balkan-Physical-Union, Aug 22-26, 2006, Istanbul, Turke

Kinetic and mechanistic study on the reactions of ruthenium(II) chlorophenyl terpyridine complexes with nucleobases, oligonucleotides and DNA

© The Royal Society of Chemistry. In this study, we investigated the ability of Ru(ii) polypyridyl complexes to act as DNA binders. The substitution reactions of three Ru(ii) chlorophenyl terpyridine complexes, i.e. [Ru(Cl-Ph-tpy)(en)Cl]Cl (1), [Ru(Cl-Ph-tpy)(dach)Cl]Cl (2) and [Ru(Cl-Ph-tpy)(bpy)Cl]Cl (3) (Cl-Ph-tpy = 4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine, en = 1,2-diaminoethane, dach = 1,2-diaminocyclohexane, bpy = 2,2′-bipyridine), with a mononucleotide guanosine-5′-monophosphate (5′-GMP) and oligonucleotides such as fully complementary 15-mer and 22-mer duplexes with a centrally located GG-binding site for DNA, and fully complementary 13-mer duplexes with a centrally located GG-binding site for RNA were studied quantitatively by UV-Vis spectroscopy. Duplex RNA reacts faster with complexes 1-3 than duplex DNA, while shorter duplex DNA (15mer GG) reacts faster compared with 22mer GG duplex DNA. The measured enthalpies and entropies of activation (ΔH≠ > 0, ΔS≠ < 0) support an associative mechanism for the substitution process. 1H NMR spectroscopy studies performed on complex 3 demonstrated that after the hydrolysis of the Cl ligand, it is capable to interact with guanine derivatives (i.e., 9-methylguanine (9MeG) and 5′-GMP) through N7, forming monofunctional adducts. The molecular structure of the cationic compound [Ru(Cl-Ph-tpy)(bpy)Cl]Cl (3) was determined in the solid state by X-ray crystallography. The interactions of 1-3 with calf thymus (CT) and herring testes (HT) DNA were examined by stopped-flow spectroscopy, in which HT DNA was sensibly more reactive than CT DNA. The reactivity towards the formation of Ru-DNA adducts was also revealed by a gel mobility shift assay, showing that complexes 1 and 2 have a stronger DNA unwinding ability compared to complex 3. Overall, the complexes with bidentate aliphatic diamines proved to be superior to those with bpy in terms of capability to bind to the here studied biomolecules

Synthesis and characterization of platinum(IV)-complexes with S-alkyl derivatives of thiosalicylic acid and the crystal structure of the S-butyl derivative of thiosalicylic acid

© 2017, University of Kragujevac, Faculty of Science. All rights reserved. New platinum(IV)-complexes with S-alkyl derivatives of thiosalicylic acid (alkyl = benzyl-(L1), methyl-(L2), ethyl-(L3), propyl-(L4), butyl-(L5)) have been synthesized and characterized by microanalysis, infrared spectroscopy, and1H and13C NMR spectroscopy. The bidentate S,O ligand precursor, the S-butyl derivative of thiosalicylic acid (S-bu-thiosal), was prepared, and its crystal structure was determined. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a DMSO-water system. S-bu-thiosal crystallized in a P21/c space group of a monoclinic crystal system with a = 8.0732 (3) Å, b = 19.6769 (4) Å, c = 8.2291 (3) Å and Z = 4. S-bu-thiosal also has a coplanar geometry