The influence of Si and V on the kinetics of phase transformation and microstructure of rapidly solidified Al-Fe-Zr alloys

The influence of Si and V on the precipitation kinetics of the rapidly solidified (RS) Al-Fe-Zr alloys is presented. Precipitation kinetics and microstructural development of RS Al-Fe-Zr alloys with Si or V addition have been investigated by the combination of four point electrical resistance measurement, optical microscopy, transmition electron microscopy (TEM) and scanning electron microscopy (SEM). For verification of the electrical resistivity measurement results differential scanning calorimetry (DSC) and differential thermal analysis (DTA) was also applied. Rapidly solidified samples, in the form of thin ribbons, were prepared with the single roll melt spun technique. For determination of the distinctive temperatures at which microstructural transformations occur in-situ electrical resistivity measurement during heating of the ribbons with various constant heating rates has been used. It was found that microstructure decomposition depends on heating rate and shifts to higher temperatures with increasing heating rate. After heating above the distinctive transition temperatures, heating was stopped and microstructure of the samples examined by electron microscopy

Učinkovitost i kvaliteta indukcijskog zagrijavanja i kaljenja osovina startera dizel motora

Presented work discusses a complex process of inductive heating and quenching of carbon steel planetary shafts for diesel engine starters. On the measurements base of temperature fields on the surface of the planetary shafts by thermographic camera and theoretical knowledge, a mathematical model for temperature conditions determination in the shaft during the entire process of heating and quenching was carried out. On the basis of developed mathematical model a computer program was developed, and used for analyses and induction hardening process optimization of planetary shafts.U ovom se radu raspravlja o složenom procesu indukcijskog zagrijavanja i kaljenja osovina iz ugljičnog čelika za pokretanje dizelskih motora. Na temelju rezultata mjerenja temperaturnih polja na površini osovina termografskom kamerom i teorijskih spoznaja, razvijen je matematički model temperaturnih uvjeta tijekom procesa zagrijavanja i kaljenja osovina. Na temelju postavljenog matematičkog modela razvijen je računalni program koji je korišten za analizu i optimizaciju procesa zagrijavanja osovina

Synthesis and characterization of hardened Cu-Fe-Ni-P alloy

In the manufacturing industry of electrical contacts, the prohibition of the use of toxic metals (Cd, Be), and desire to avoid the alloying with precious metals (Ag) has created a need for new alloys with good electrical conductivity and high mechanical properties at elevated temperatures. As a potentially useful material for this purpose, we have analyzed the continuously cast Cu-Fe-Ni-P alloy in various heat treatment conditions. Sequence of phase transformations during heat treatment was followed by 4 point D.C. electrical resistivity measuring method, and analyzed by scanning (SEM) and transmission (TEM) electron microscopy. Measurements of Vickers hardness and electrical conductivity after various heat treatment procedures indicate on high potential of Cu-Fe-Ni-P alloys as a material for electrical contacts

Microstructure evolution and thermal stability of rapidly solidified Al-Ni-Co-RE alloy

In the frame of this work, Al-5Ni-1Co-3RE (RE-Rare Earth (Mischmetal)) rapidly solidified ribbons were manufactured and analyzed. The morphology of the as-cast structure, as well as the microstructural features were analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Thermal stability has been investigated by combination of four point scanning electrical resistivity measurement (ER), differential scanning calorimetry (DSC) and microhardness measurement. From the results we can conclude, that Al-5Ni-1Co-3RE rapidly solidified alloys have good thermal stability due to very slow coarsening kinetics of precipitated particles

Liver mitochondrial membrane permeability modulation in insulin-resistant, uninephrectomised male rats by Clerodendrum volubile P. Beauv and Manihot esculenta Crantz

Background: Non-alcoholic fatty liver disease, which occurs in people who are not alcohol drinkers, describes some of the pathogenic conditions that may be in the least characterized by simple steatosis or can be as serious as non-alcoholic steatohepatitis and cirrhosis. Its mechanistic pathogenesis has been said to arise from insulin resistance and oxidative stress, which may be compounded by obesity. An experimental model showing, systemic insulin resistance, obesity and accumulated hepatic fatty acids was created in adult male rats using high-fat diet manipulation and surgical removal of the left kidney (uninephrectomy). This study sought to identify the impact of these multiple burdens on the liver mitochondrial membrane permeability transition pore opening, and the possible in vitro effects of the extracts of Clerodendrum volubile and Manihot esculenta leaves on the membrane permeabilization. Results: The results indicated that the methanolic extract of Clerodendrum volubile leaf inhibited mitochondrial membrane pore opening in the insulin resistance condition or when it is followed by uni-nephrectomy, while the ethanolic extract of Manihot esculenta leaf does the same in the insulin resistance condition both prior to and following uni-nephrectomy. Conclusion: Since the vegetable extracts were able to abrogate mitochondrial pore opening at low concentrations, the structural integrity of the mitochondria can possibly be restored over time if treated by the vegetable extracts. Research efforts should, therefore, be made to harness the drugability of the bioactives of these vegetables for use in the treatment of non-alcoholic fatty liver disease arising from insulin resistance and renal failure.Fil: Ajayi, Ebenezer Idowu O. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Osun State University; Nigeria. National Institute of Pharmaceutical Education and Research; IndiaFil: Molehin, Olorunfemi R.. Ekiti State University; NigeriaFil: Oloyede, Omotade I.. Ekiti State University; NigeriaFil: Kumar, Vinodu. National Institute of Pharmaceutical Education and Research; IndiaFil: Amara, Venkateswara R.. National Institute of Pharmaceutical Education and Research; IndiaFil: Kaur, Jasmine. National Institute of Pharmaceutical Education and Research; IndiaFil: Karpe, Pinakin. National Institute of Pharmaceutical Education and Research; IndiaFil: Tikoo, Kulbhushan B.. National Institute of Pharmaceutical Education and Research; Indi

Regional fat depot masses are influenced by protein-coding gene variants

Waist-to-hip ratio (WHR) is a prominent cardiometabolic risk factor that increases cardio-metabolic disease risk independently of BMI and for which multiple genetic loci have been identified. However, WHR is a relatively crude proxy for fat distribution and it does not capture all variation in fat distribution. We here present a study of the role of coding genetic variants on fat mass in 6 distinct regions of the body, based on dual-energy X-ray absorptiometry imaging on more than 17k participants. We find that the missense variant CCDC92(S70C), previously associated with WHR, is associated specifically increased leg fat mass and reduced visceral but not subcutaneous central fat. The minor allele-carrying transcript of CCDC92 is constitutively more highly expressed in adipose tissue samples. In addition, we identify two coding variants in SPATA20 and UQCC1 that are associated with arm fat mass. SPATA20(K422R) is a low-frequency variant with a large effect on arm fat only, and UQCC1(R51Q) is a common variant reaching significance for arm but showing similar trends in other subcutaneous fat depots. Our findings support the notion that different fat compartments are regulated by distinct genetic factors.Peer reviewe

Phenomena in penetrating piercing bullets in armored steel plate

The presented work studied the response of new generation armored steel plates PROTAC 500 to the ballistic testing with armored piercing bullets with a core of tungsten carbide, charge 7,62 mm, and interactions between the piercing bullets and the armored steel plate were also investigated. The most obvious and significant phenomena in penetrating of the piercing bullets Nammo AP8 in steel target PROTAC 500 are strain hardening of steels, the appearance of cracks and local failure, adiabatic shear bands (ASB) with related phase transformations, and melting as well as alloying at the border of the bullet / the steel plate