This work aims to evaluate the influence of laser power and reinforcement feeding rate on microstructure, hardness, wear behavior NbC-reinforced Hastelloy C276TM alloy composite coatings. From a dual system, one-step metal-matrix coatings were deposited with 10, 30, 50% mass NbC powder powers 1.5 3.0 kW. Coatings kW 30% showed some degree porosity due combination melting pool temperature. Laser...

In glucose-limited aerobic chemostat cultures of a wild-type Saccharomyces cerevisiae and a derived hxk2 null strain, metabolic fluxes were identical. However, the concentrations of intracellular metabolites, especially fructose 1,6-bisphosphate, and hexose-phosphorylating activities differed. Interestingly, the hxk2 null strain showed a higher maximal growth rate and higher Crabtree threshold ...

The interaction between Escherichia coli O157:H7 and its specific bacteriophage PP01 was investigated in chemostat continuous culture. Following the addition of bacteriophage PP01, E. coli O157:H7 cell lysis was observed by over 4 orders of magnitude at a dilution rate of 0.876 h(-1) and by 3 orders of magnitude at a lower dilution rate (0.327 h(-1)). However, the appearance of a series of phag...

The energetics and accumulation of solutes in Saccharomyces cerevisiae were investigated for cells grown aerobically in a chemostat under NaCl stress and glucose limitation. Changed energy requirements in relation to external salinity were examined by energy balance determinations performed by substrate and product analyses, with the latter including heat measurements by microcalorimetry. In bo...

We study the chemostat model for one species competing for one nutrient using a Lyapunov-type analysis. We design the dilution rate function so that all solutions of the chemostat converge to a prescribed periodic solution. In terms of chemostat biology, this means that no matter what positive initial levels for the species concentration and nutrient are selected, the long-term species concentr...

Abstract Background We compared amino acid leakage among high-volume pre-dilution on-line hemodiafiltration (Pre O-HDF), hemodialysis (HD), and post-dilution (Post O-HDF). Subjects methods The subjects were 9 patients. For HD, the total dialysate flow rate was established as 500 mL/min. Pre O-HDF, it 600 mL/min, under a replacement fluid volume of 90 L. Post 10 In both procedures, duration trea...

The dynamics of a model of a free-living nitrogen-fixing population, grown in a chemostat alone or in competition with a non-nitrogen-fixing population, was studied through bifurcation analysis. It is demonstrated that the ability of the nitrogen-fixing population to survive depends on the ammonia and carbon source concentrations and the kinetics parameters of the system. Under competitive cond...

Continuous production of nisin in laboratory media and whey permeate was investigated using a packed-bed bioreactor. Lactococcus lactis subsp. lactis ATCC 11454 was immobilized by natural attachment to fibre surfaces and entrapment in the void volume within spiral wound fibrous matrix. The inoculated bioreactor was fed M17 medium and effect of pH, temperature, dilution rate, and substrate conce...

The influence of dilution rate on the production of biomass, ethanol, and invertase in an aerobic culture of Succharornyces carlsbergensis was studied in a glucoselimited chemostat culture. A kinetic model was developed to analyze the biphasic growth of yeast on both the glucose remaining and the ethanol produced in the culture. The model assumes a double effect where glucose regulates the flux...

In vitro dilution models are used to simulate in vivo drug concentration-time profiles and thus to study the effects of various antibiotic concentrations on the bacteria investigated. The major disadvantage of these models is permanent dilution of the bacterial culture, which falsifies the resulting kill curves. Known equations, which usually correct bacterial loss by simple first-order kinetic...