Microstructure Study of Diffusion Bonding of Centrifuged Structural Steel-Bronze

One of the methods to prevent unsuitable lubrication of moving components of devices and machinery is using bi-metal and three-metal bearings. Centrifugal casting process is one of the manufacturing methods that is used for such bearings. In this study, the purpose is microstructure evaluation of the bonding location and length determination of diffusion bond in structural steel-bronze. A mold made of structural steel with inner diameter of 240mm, length of 300mm and thickness of 10mm was coated by a 6mm film of bronze under centrifugal casting process. At first, a bronze ingot with dimension of 5mm×10mm×20mm is located inside of the hollow cylindrical mold and then the two ends of it will be sealed. During mold rotation with the rate of 800 rpm, two high power flames are used for heating the mold under Ar gas atmosphere to melt the bronze ingot at 1000°C. After 15minutes, the system is cooled rapidly. Results showed that the diffusion bonding of bronze in structural steel to depth of 1.2μm from the bonding line was obtained. In this bonding, copper element was diffused to 50% of its initial concentration

Microstructure Study of Diffusion Bonding of Centrifuged Structural Steel-Bronze

One of the methods to prevent unsuitable lubrication of moving components of devices and machinery is using bi-metal and three-metal bearings. Centrifugal casting process is one of the manufacturing methods that is used for such bearings. In this study, the purpose is microstructure evaluation of the bonding location and length determination of diffusion bond in structural steel-bronze. A mold made of structural steel with inner diameter of 240mm, length of 300mm and thickness of 10mm was coated by a 6mm film of bronze under centrifugal casting process. At first, a bronze ingot with dimension of 5mm×10mm×20mm is located inside of the hollow cylindrical mold and then the two ends of it will be sealed. During mold rotation with the rate of 800 rpm, two high power flames are used for heating the mold under Ar gas atmosphere to melt the bronze ingot at 1000˚C. After 15minutes, the system is cooled rapidly. Results showed that the diffusion bonding of bronze in structural steel to depth of 1.2μm from the bonding line was obtained. In this bonding, copper element was diffused to 50% of its initial concentration

Recombinant plasmid KMP-11 gene of Leishmania major (pcKMP-11): Production, characterization and sequencing

Aim: Kinetoplastid membrane protein-11 expresses life cycle stages of all kinetoplastidae parasites. Previous studies have demonstrated that kinetoplastidae KMP-11 gene is highly conserved and may be useful for vaccine strategies against Leishmaniasis. In this study, we isolated Leishmania major (MRHO/IR/75/ER) KMP-11 gene and formulated a pcKMP-11 recombinant expressing plasmid as a candidate DNA vaccine against cutaneous Leishmaniasis. Methods: After gene amplification, KMP-11 fragments were cloned into pTZ57R/T standard cloning vector and transformed in E. coli, then subcloned into pcDNA3 eukaryotic expression vector and pcKMP-11 recombinant plasmid was transfected to CHO eukaryotic cells. Amplification, sequencing, cloning and transfection of gene were performed successfully. mRNA transcription of KMP-11 gene in CHO cells was confirmed by RT-PCR methods. Results: Sequence results were compared with other records of kmp-11 in gene bank and a 97-99 identity was showed. Comparison of KMP-11 protein with other records showed that this protein have 92 amino acids. Additionally, a silico analysis of 3D structures of the wild type and double mutant KMP-11 proteins show that the mutations in position 16 and 41 have led to a change in structure conformation and stability. Conclusion: Present results show that KMP-11 can be an excellent candidate for immunization against leishmaniasis