Structure and Mechanical Behaviour of Cu‐Zr‐Ni‐Al Amorphous Alloys Produced by Rapid Solidification

The amorphous ribbons of Cu50Zr40Ni5Al5 alloy were manufactured by rapid solidification. The ribbons were investigated by X‐ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM‐EDX) and differential scanning calorimetry (DSC). The activation energy of the crystallisation in amorphous alloys was determined by Kissenger technique. The mechanical properties of the ribbons were characterized using Vickers microhardness (HV) tester. According to the XRD and SEM results, the Cu50Zr40Ni5Al5 alloys have a fully amorphous structure. The EDX analysis of the ribbons showed that compositional homogeneity of the Cu50Zr40Ni5Al5 alloy was fairly high. From the DSC curves of the amorphous ribbons, it was determined that glass transition temperature (Tg) is around 440–442°C and super‐cooled liquid region (ΔTx = Tx - Tx) before crystallisation is around 61–64°C. The microhardness of the as‐quenched ribbons was measured about 550 HV. However, this microhardness value decreased with increasing annealing temperature and it was calculated about 465 HV after annealing temperature of 800°C

Phase Identification and Size Evaluation of Mechanically Alloyed Cu-Mg-Ni Powders

Ternary mixture of Cu, Mg, and Ni with the nominal composition of nanocrystalline Cu50Mg25Ni25 (in at.%) was milled for 25 hours. Analysis of an X‐ray diffraction pattern (XRD) and transmission electron microscopy (TEM) was used to characterize the chemical phases and microstructure of the final product, which is shown to consist of ternary alloy of Cu‐Mg‐Ni with FCC structure along with small amounts of FCC MgO and Mg0.85Cu0.15. The good agreement between the size values obtained by XRD and TEM is attributed to the formation of defect‐free grains with no substructure during ball milling. Dynamic recrystallization may be a possible mechanism for the emergence of such small grains (<20 nm). The particle size distribution and morphological changes of Cu–Mg–Ni powders were also analyzed by scanning electron microscopy (SEM). According to the SEM results, the particle size of the powders decreased with increasing milling time. Lattice parameter of the Cu‐Mg‐Ni ternary FCC alloy formed during mechanical alloying increased with increase in milling time from 3.61 to 3.65 Å after 20 hours milling

Efecto de annealing sobre las propiedades estructurales, térmicas y mecánicas de la composición de aleación binaria Al85 Ni 15

Introduction: The Al 85-Ni15 alloy with 99.99% purity of Al and Ni were prepared by an arc melting technique system. The annealing effect onthe microstructure properties, phase transformation and micro-hardness for the Al-Ni alloy system were investigated. Material and Methods:The alloys were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA) as well as Vickers micro-hardness measurement. Results and Discussion: The quantitative results confirm that the chemical composition of the alloys is very close to compositions and the microstructures are in typical lamellar morphology. Mechanical properties for the as-prepared samples and subsequently heat-treated samples were measured by a Vickers indenter. Values of the micro-hardness (HV) Conclusions: According the XRD pattern analysis a multi phases produced, such as Al, AlNi3in room temperature, Al3Ni2, Al0.42Ni0.58 at 200ºC, Al1.1Ni0.9 at 300ºC and Al 0.802Ni0.198, AlNi3 and AlNi at 400ºC, and Al0.802Ni0.198, AlNi3 and AlNi for 500ºC. Similar approached were obtained from the results of SEM and DTA measurements. Annealing treatments are visibly affecting the alloy phase formation with different phases at different temperature. and the elastic modulus (E) of the as prepared sample are 132.9±0.1 kgfmm-2 (1.329±0.1 GPa) and 80.340±0.1 GPa, respectively. Furthermore, the characteristic of the materials plasticity (δH) value was calculated to be 0.85. The micro-hardness values are decrease with the increase of annealing temperatures

Četverogodišnja studija učinkovitosti i sigurnosti entekavira u bolesnika s kroničnim hepatitisom B pozitivnih na HBeAg bez prethodne nukleoz(t)idne terapije

Entecavir is a guanosine analogue with activity against hepatitis B virus. The aim of this 4-year trial was to evaluate entecavir treatment in nucleos(t)ide-naive HBeAg-positive chronic hepatitis B patients. Forty-nine patients received entecavir and nine of them withdrew from the trial at the end of week 96. The initial mean value of alanine aminotransferase was 79.4}41.5 IU /L, and at the end of the 4-year study period, 90% of patients had alanine aminotransferase values within the normal range. At week 96, 91.7% of patients had HBV DNA <300 copies; at month 48, 90% of patients had HBV DNA <50 IU /mL. HBeAg loss was recorded in 7.1% of patients at week 96 and in 12.5% at month 48. The rate of HBeAg seroconversion was 4.8% at week 96 and 7.5% at month 48. The rate of HBsAg seroconversion was 2.1% at week 96 and 2.5% at month 48. Entecavir as a potent and safe agent leading to continuous viral suppression proved to be safe and well tolerated therapy.Entekavir je analog gvanozina koji djeluje protiv virusa hepatitisa B. Cilj ove četverogodišnje studije bio je procijeniti liječenje entekavirom kod bolesnika s kroničnim hepatitisom B pozitivnih na HBeAg bez prethodne nukleoz(t)idne terapije. Ukupno je 49 bolesnika primalo entekavir, a devetoro ih se povuklo s terapije na kraju 96. tjedna. Početna srednja vrijednost alanin aminotransferaze bila 79,4}41,5 IU /L, dok je nakon 4 godine vrijednost alanin aminotransferaze bila u normalnim granicama kod 90% bolesnika. U 96. tjednu je <300 kopija HBV DNA zabilježeno u 91,7% bolesnika, a u 48. mjesecu je 48,90% bolesnika imalo <50 IJ/mL HBV DNA. Gubitak HBeAg zabilježen je u 7,1% bolesnika u 96. tjednu te u 12,5% bolesnika u 48. mjesecu. Stopa serokonverzije HBeAg iznosila je 4,8% u 96. tjednu i 7,5% u 48. mjesecu. Stopa serokonverzije HBsAg bila je 2,1% u 96. tjednu i 2,5% u 48. mjesecu. Sigurnost terapije bila je dobra. Bolesnici su dobro podnosili entekavir, snažan i siguran lijek koji dovodi do ustaljenog suzbijanja virusa

Četverogodišnja studija učinkovitosti i sigurnosti entekavira u bolesnika s kroničnim hepatitisom B pozitivnih na HBeAg bez prethodne nukleoz(t)idne terapije

Entecavir is a guanosine analogue with activity against hepatitis B virus. The aim of this 4-year trial was to evaluate entecavir treatment in nucleos(t)ide-naive HBeAg-positive chronic hepatitis B patients. Forty-nine patients received entecavir and nine of them withdrew from the trial at the end of week 96. The initial mean value of alanine aminotransferase was 79.4}41.5 IU /L, and at the end of the 4-year study period, 90% of patients had alanine aminotransferase values within the normal range. At week 96, 91.7% of patients had HBV DNA <300 copies; at month 48, 90% of patients had HBV DNA <50 IU /mL. HBeAg loss was recorded in 7.1% of patients at week 96 and in 12.5% at month 48. The rate of HBeAg seroconversion was 4.8% at week 96 and 7.5% at month 48. The rate of HBsAg seroconversion was 2.1% at week 96 and 2.5% at month 48. Entecavir as a potent and safe agent leading to continuous viral suppression proved to be safe and well tolerated therapy.Entekavir je analog gvanozina koji djeluje protiv virusa hepatitisa B. Cilj ove četverogodišnje studije bio je procijeniti liječenje entekavirom kod bolesnika s kroničnim hepatitisom B pozitivnih na HBeAg bez prethodne nukleoz(t)idne terapije. Ukupno je 49 bolesnika primalo entekavir, a devetoro ih se povuklo s terapije na kraju 96. tjedna. Početna srednja vrijednost alanin aminotransferaze bila 79,4}41,5 IU /L, dok je nakon 4 godine vrijednost alanin aminotransferaze bila u normalnim granicama kod 90% bolesnika. U 96. tjednu je <300 kopija HBV DNA zabilježeno u 91,7% bolesnika, a u 48. mjesecu je 48,90% bolesnika imalo <50 IJ/mL HBV DNA. Gubitak HBeAg zabilježen je u 7,1% bolesnika u 96. tjednu te u 12,5% bolesnika u 48. mjesecu. Stopa serokonverzije HBeAg iznosila je 4,8% u 96. tjednu i 7,5% u 48. mjesecu. Stopa serokonverzije HBsAg bila je 2,1% u 96. tjednu i 2,5% u 48. mjesecu. Sigurnost terapije bila je dobra. Bolesnici su dobro podnosili entekavir, snažan i siguran lijek koji dovodi do ustaljenog suzbijanja virusa

Coil embolization of iatrogenic coronary-pulmonary arterial fistula after heart transplantation

WOS: 000357329900014PubMed ID: 2613917

Mg65Ni20Y15-xAgx (X=1, 2, 3, 5) ALLOYS PREPARED VIA ATMOSPHERE CONTROLLED INDUCTION SYSTEM

In this work, Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys were manufactured by atmosphere controlled induction system. The effect of Ag ratio on the microstructural properties, micro-hardness, density, and homogeneity of the Mg–Ni–Y alloys were investigated. These alloys were characterized by X-ray diffraction (XRD), optical microscopy, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Vickers micro-hardness measurement. According to XRD results, Ni3Y and Mg6Ni phases were observed as well as AgY and Ag17Mg54 phases, which were obtained in alloys. The quantitative results of EDX analysis confirm that the chemical composition of the obtained phases is very close and their homogeneities are so high. The average micro-hardness values of the ingot alloys were measured between 208 and 266 HV for matrix. The elastic modulus and densities of the Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys increased by increasing Ag in the alloys and they were determined in the range of 58.18–68.12 GPa and 3.14–3.53 g/cm3, respectively.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Measurement on the neutron and gamma radiation shielding performance of boron-doped titanium alloy Ti50Cu30Zr15B5 via arc melting technique

The significance of radiation shielding is on the rise due to the expanding areas exposed to radiation emissions. Consequently, there is a critical need to develop metal alloys and composites that exhibit excellent capabilities in absorbing neutron and gamma rays for effective radiation shielding. Low-density Ti-based alloys with controlled structural properties can be used for radiation protection purposes. The present research investigates boron-doped Ti-based alloy, Ti50Cu30Zr15B5, which is synthesized by arc melting technique, and its structural, mechanical properties, neutron, and gamma-ray transmission rate were investigated. Monte Carlo N-Particle simulation (MCNP6.2) code is used for calculating the Thermal (2.53 × 10−8 MeV) and fast (2 MeV) neutron transmission ratio (I/I0) dependent on the sample thickness. The Phy-x program is employed for calculating the gamma-ray LAC, MAC, HVL, TVL, and MFP values. The calculated neutron shielding performance parameters of Ti50Cu30Zr15B5 alloy were compared with materials in the literature. It was found that Ti50Cu30Zr15B5 alloy demonstrated impressive physical characteristics, suggesting that it can serve as a promising alloy for neutron and gamma-ray shielding applications