Enhanced β-galactosidase production by supplementing whey with cauliflower waste

Among the five Kluyveromyces marxianus strains tested for β-galactosidase production, K. marxianus NCIM 3465 showed maximum enzyme activity of 1.62 IU mg⁻¹ dry weight. Different levels (5–25%, w/v) of dried cauliflower waste were incorporated into whey to evaluate the effect of its supplementation on enzyme production. Although a marginal increase in enzyme production was seen by incorporating 5% and 10% cauliflower waste in whey, nearly 15% increase in β-galactosidase production was observed when cauliflower waste level was increased to 20% compared with whey alone. Supplementing whey with 20% cauliflower waste also decreased the production time. Lactose concentration in whey, mainly responsible for increasing the biological oxygen demand load of the effluent water, decreased from 4.2% to nearly 0% at 24 h. Thus, this study demonstrated that both these by-products/residues could be effectively used for β-galactosidase production at commercial scale.     

Positron emission tomography. Tracing how and why it is sosuccessful

PET is one of the most advanced medical imaging systems widely applied to medical research and clinical use. The present PET scanning technique cannot be performed in small animals such as mice. The detector is not optimal with respect to radiotracer sensitivity due to the lack of spatial resolution. (The problem is further exacerbated due to the lack of a computer model and the unknown amount of radiotracers to be administered for viable detection in small animals.) Thus, the authors are working on a feasibility study to show whether present PET scanning systems can be modified to identify active tumor foci in an orthotopic mouse model of human pancreatic cancer. This way the efficacy of selected standard chemotherapy drugs and novel biological agents can be tested. Ultimately, the goal is the development of novel therapeutic agents against human pancreatic cancer     

Effect of wood species on corrosion behavior of carbon steel and stainless steels in black liquors

Black liquors produced by pulping different wood species can have different corrosivity towards carbon steel equipment in pulp mills. Inorganic constituents of black liquor alone do not correlate well with the corrosivity of different black liquors. Organic constituents of the black liquor have significant effect on determining its corrosivity. However, understanding of the role of individual organic constituents or group of constituents of black liquors in overall black liquor corrosivity is generally lacking. The objective of this study was to determine the effect selected wood species on the corrosivity of their black liquors which contained similar inorganic constituents. The role of black liquor constituent, pyrocatechols, whose presence in the black liquor has been associated with an increase in corrosion of carbon steel, was also studied. Results from electrochemical tests point to the mechanisms by which the catechols may participate in the accelerated corrosion of carbon steels. This study demonstrates the role of organic constituents of the black liquor in determining its corrosivity.     

Collapse of conical cavities in aluminium metal under shock wave impact

Under shock wave impact the conical free surface of the metal collapses and a metallic jet with a velocity exceeding 10 km/s is squirted out of the metallic target. Variation in the jet tip velocity when the cavity half angle ranges from 60 down to 7.5° has been studied over three different shock pressures. The jet velocity has been found to increase with the decrease in the angle of the conical free surface and as the angle approaches zero the jet tip velocity attains a value near to the limit set by hydrodynamic theory for non-compressible fluids. The effect of aerodynamic drag on this type of jet has been studied and it has been found that the jet formed by the collapse of a small angle conical cavity quickly slows down while travelling in air, whereas the jet coming out of large angle cavity suffers a small retardation. Theoretical explanation and experimental evidence in support of this fact are also presented.     

The effect of temperature and vibration on emulsion stability of mayonnaise in two different package types

Mayonnaise in two different packages was compared for its susceptibility to vibration-induced breakdown. The researchers investigated the effect of truck vibration on emulsion stability and compared two different package systems. The containers were 32 oz glass and 32 oz polyethylene terephthalate (PET). Mayonnaise was conditioned at three different temperatures (40°, 72° and 100 °F), for three time periods (21, 26 and 36 days), and vibrated at normal and worst-case transportation g levels. Emulsion stability was quantified by specific gravity, percentage of surface oil, and qualitatively rated by a visual pass/fail test. The specific gravity measure positively correlated to surface oiling. Glass containers showed a higher rate of emulsion failure at the worst-case vibration levels. No consistent difference in emulsion breakdown was found between plastic and glass at the normal transportation g levels.