The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Hiroyuki Mori - One of the best experts on this subject based on the ideXlab platform.
-
solid solution Copper Alloys with high strength and high electrical conductivity
Scripta Materialia, 2013Co-Authors: Kazunari Maki, Yuki Ito, Hirotaka Matsunaga, Hiroyuki MoriAbstract:Solid-solution Copper Alloys are standard and widely used conductive materials. However, it is generally considered difficult to significantly improve the balance between the strength and electrical conductivity of these Alloys. Here, we designed Copper Alloys that exhibit high strength and conductivity by using solid-solution hardening enhanced by supersaturation with Mg. Cu–Mg alloy has a conductivity at least three times higher than that of the representative solid-solution Cu–Sn, while retaining comparable strength. Cu–Al–Mg alloy showed greater strength and conductivity than Cu–Sn.
Lei Xu - One of the best experts on this subject based on the ideXlab platform.
-
fabrication of tungsten Copper Alloys by microwave hot pressing sintering
Journal of Alloys and Compounds, 2016Co-Authors: Lei Xu, C Srinivasakannan, Libo Zhang, Jinhui PengAbstract:Abstract The tungsten–Copper Alloys were prepared and characterized utilizing pressureless microwave sintering and hot pressure microwave sintering. The performance of tungsten–Copper alloy was assessed based on the relative density and hardness. The influence of different pressure and Copper content on the microstructure of tungsten Copper alloy has been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Experimental results indicate tungsten–Copper alloy with excellent performance under microwave hot press sintering. The relative density of the alloy was estimated to be 98.14% at a sintering temperature of 1100 °C, applied pressure of 30 MPa for duration of 1 h. The relative density was found to increase with increase in the applied pressure. The microstructure of tungsten–Copper alloy sintered by microwave hot press method was more uniform having a compact matrix.
Jinhui Peng - One of the best experts on this subject based on the ideXlab platform.
-
fabrication of tungsten Copper Alloys by microwave hot pressing sintering
Journal of Alloys and Compounds, 2016Co-Authors: Lei Xu, C Srinivasakannan, Libo Zhang, Jinhui PengAbstract:Abstract The tungsten–Copper Alloys were prepared and characterized utilizing pressureless microwave sintering and hot pressure microwave sintering. The performance of tungsten–Copper alloy was assessed based on the relative density and hardness. The influence of different pressure and Copper content on the microstructure of tungsten Copper alloy has been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Experimental results indicate tungsten–Copper alloy with excellent performance under microwave hot press sintering. The relative density of the alloy was estimated to be 98.14% at a sintering temperature of 1100 °C, applied pressure of 30 MPa for duration of 1 h. The relative density was found to increase with increase in the applied pressure. The microstructure of tungsten–Copper alloy sintered by microwave hot press method was more uniform having a compact matrix.
-
Fabrication of tungsten–Copper Alloys by microwave hot pressing sintering
Journal of Alloys and Compounds, 2016Co-Authors: C Srinivasakannan, Libo Zhang, Jinhui Peng, Mi Yan, Hongying Xia, Shenghui GuoAbstract:Abstract The tungsten–Copper Alloys were prepared and characterized utilizing pressureless microwave sintering and hot pressure microwave sintering. The performance of tungsten–Copper alloy was assessed based on the relative density and hardness. The influence of different pressure and Copper content on the microstructure of tungsten Copper alloy has been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Experimental results indicate tungsten–Copper alloy with excellent performance under microwave hot press sintering. The relative density of the alloy was estimated to be 98.14% at a sintering temperature of 1100 °C, applied pressure of 30 MPa for duration of 1 h. The relative density was found to increase with increase in the applied pressure. The microstructure of tungsten–Copper alloy sintered by microwave hot press method was more uniform having a compact matrix.
Kazunari Maki - One of the best experts on this subject based on the ideXlab platform.
-
solid solution Copper Alloys with high strength and high electrical conductivity
Scripta Materialia, 2013Co-Authors: Kazunari Maki, Yuki Ito, Hirotaka Matsunaga, Hiroyuki MoriAbstract:Solid-solution Copper Alloys are standard and widely used conductive materials. However, it is generally considered difficult to significantly improve the balance between the strength and electrical conductivity of these Alloys. Here, we designed Copper Alloys that exhibit high strength and conductivity by using solid-solution hardening enhanced by supersaturation with Mg. Cu–Mg alloy has a conductivity at least three times higher than that of the representative solid-solution Cu–Sn, while retaining comparable strength. Cu–Al–Mg alloy showed greater strength and conductivity than Cu–Sn.
Anna Różańska - One of the best experts on this subject based on the ideXlab platform.
-
Antimicrobial effect of Copper Alloys on Acinetobacter species isolated from infections and hospital environment
Antimicrobial Resistance & Infection Control, 2018Co-Authors: Anna Różańska, Agnieszka Chmielarczyk, Dorota Romaniszyn, Grzegorz Majka, Małgorzata BulandaAbstract:Background An increased proportion of Gram-negative bacteria have recently been reported among etiologic agents of infection. In Poland, Acinetobacter baumannii is a big problem for hospitals, especially intensive care units. Touch surfaces made from materials with antimicrobial properties, especially Copper Alloys, are recommended as a supplementary method of increasing biological safety in the hospital environment. Aim of the study The objective of this study is to determine the susceptibility to selected Copper Alloys of three clinical Acinetobacter baumannii strains, one Acinetobacter lwoffi and an A. pittii strain isolated from the hospital environment. Material and method The modification of the Japanese Standard, which the ISO 22196:2011 norm was used for testing antimicrobial properties of CuZn37, CuSn6 and CuNi18Zn20 and Cu-ETP and stainless steel as positive and negative control, respectively. Results The highest cidal efficiency, expressed as both time and the degree of reduction of the initial suspension density, against all of the tested Acinetobacter strains was found for ETP Copper. But, the results of our study also confirmed effective activity (bacteriocidal or bacteriostatic) of Copper Alloys selected for the study, contrary to the stainless steel. The reduction in bacterial suspension density is significantly different depending on the strain and Copper alloy composition. Conslusions The results of our study confirmed the effective antibacterial activity of Copper and its selected Alloys against clinical Acinetobacter baumannii and Acinetobacter lwoffii strains, and Acinetobacter pittii strain isolated from the hospital environment.
-
Antibiotic resistance, ability to form biofilm and susceptibility to Copper Alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards.
Antimicrobial Resistance and Infection Control, 2017Co-Authors: Anna Różańska, M. Walkowicz, P. Osuch, Agnieszka Chmielarczyk, Dorota Romaniszyn, Małgorzata Bulanda, Tadeusz KnychAbstract:Despite the employment of sanitary regimes, contact transmission of the aetiological agents of hospital infections is still exceedingly common. The issue of microbe transmission becomes particularly important when facing multidrug-resistant microorganisms such as methicillin-resistant staphylococci. In the case of deficiencies in cleaning and disinfection procedures, hospital equipment made of Copper Alloys can play an important role, complementing traditional hospital hygiene procedures. The objective of this study was to characterize staphylococcal strains isolated from touch surfaces in Polish hospital wards in terms of their drug resistance, ability to form biofilm and susceptibility to antimicrobial activity of Copper Alloys. The materials for the study were 95 staphylococcal strains isolated from touch surfaces in 13 different hospital wards from Malopolska province (the south of Poland). Phenotypic and genotypic antibiotic resistance were checked for erythromycin, clindamycin, gentamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and mupirocin. Biofilm formation ability for the tested strains was checked with the use of culture on Congo red agar. Susceptibility to Copper, tin bronze, brass and new silver was tested using a modification of the Japanese standard. Over 67% of the analysed staphylococcal strains were methicillin-resistant (MR). Four strains were resistant to all of the tested antibiotics, and 14 were resistant to all except mupirocin. Strains classified as MR had significantly increased resistance to the remaining antibiotic groups. About one-third of the analysed strains revealed biofilm-forming ability. Among the majority of species, biofilm-forming and non-biofilm-forming strains were distributed evenly; in the case of S. haemolyticus only, negative strains accounted for 92.8%. Susceptibility to Copper Alloys was different between strains and rather lower than in the case of the SA strain selected for comparison. Coagulase-negative staphylococci, the most commonly isolated in Polish hospital wards, should not be neglected as an infection risk factor due their high antibiotic resistance. Our experiments confirmed that touch surfaces made of Copper Alloys may play an important role in eliminating bacteria from the hospital environment.
-
Antibiotic resistance, ability to form biofilm and susceptibility to Copper Alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards
Antimicrobial Resistance & Infection Control, 2017Co-Authors: Anna Różańska, M. Walkowicz, P. Osuch, Agnieszka Chmielarczyk, Dorota Romaniszyn, Małgorzata Bulanda, Tadeusz KnychAbstract:Background Despite the employment of sanitary regimes, contact transmission of the aetiological agents of hospital infections is still exceedingly common. The issue of microbe transmission becomes particularly important when facing multidrug-resistant microorganisms such as methicillin-resistant staphylococci. In the case of deficiencies in cleaning and disinfection procedures, hospital equipment made of Copper Alloys can play an important role, complementing traditional hospital hygiene procedures. The objective of this study was to characterize staphylococcal strains isolated from touch surfaces in Polish hospital wards in terms of their drug resistance, ability to form biofilm and susceptibility to antimicrobial activity of Copper Alloys. Methods The materials for the study were 95 staphylococcal strains isolated from touch surfaces in 13 different hospital wards from Małopolska province (the south of Poland). Phenotypic and genotypic antibiotic resistance were checked for erythromycin, clindamycin, gentamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and mupirocin. Biofilm formation ability for the tested strains was checked with the use of culture on Congo red agar. Susceptibility to Copper, tin bronze, brass and new silver was tested using a modification of the Japanese standard. Results Over 67% of the analysed staphylococcal strains were methicillin-resistant (MR). Four strains were resistant to all of the tested antibiotics, and 14 were resistant to all except mupirocin. Strains classified as MR had significantly increased resistance to the remaining antibiotic groups. About one-third of the analysed strains revealed biofilm-forming ability. Among the majority of species, biofilm-forming and non-biofilm-forming strains were distributed evenly; in the case of S. haemolyticus only, negative strains accounted for 92.8%. Susceptibility to Copper Alloys was different between strains and rather lower than in the case of the SA strain selected for comparison. Conclusions Coagulase-negative staphylococci, the most commonly isolated in Polish hospital wards, should not be neglected as an infection risk factor due their high antibiotic resistance. Our experiments confirmed that touch surfaces made of Copper Alloys may play an important role in eliminating bacteria from the hospital environment.