QUANTITATIVE CHANGES IN THE CONCENTRATIONS OF THE MAJOR COMPONENTS OF FOUR GENOTYPES OF BARLEY GRAINS DURING MALTING AND MASHING

Four genotypes of barley, including good and poor malting varieties, were sampled as grain, green malt, kilned malt and spent grains. Each of these samples were analysed for total protein, aggregated protein, total and soluble β-glucan, starch and husk contents. Protein sub-units were separated using sodium dodecyl sulphate polyacrylamide electrophoresis. Activities of β-glucanase, endopeptidase and α-amylase were measured and starch from each sample was purified and separated into large and small granules, and analysed for total protein and sub-unit protein content. Results calculated as % of dry weight and as a proportion of the weight of dry grain showed quantitatively the changes which occurred in the components of the grain during malting and mashing. Comparisons of the composition of the genotypes at the various stages showed that the best malting variety studied, Ark Royal, was better because of moderate superiority in several characters rather than a fundamental difference in a single attribute and supports the thesis that to further improve malting quality plant breeders should select for several characters which are independently inherited.     

Comparison of methods to describe the kinetics of digestion and passage of fibre in sheep

A mathematical model is described which was developed with the objective of analysing and interpreting data from rumen-emptying studies to estimate rates of digestion (k_d) and passage (k_p) in sheep offered hay once daily. It assumed that first-order kinetics applied to digestion in and passage from the rumen within a 24 h feeding cycle. The model predictions of k_d and k_p were compared with rates of digestion estimated by incubation of the hays in dacron bags and rates of passage determined using chromium-mordanted hay, in the same experiments. The predictions for rates of passage determined over the period 5–15 h postfeeding were lower than those determined from the chromium-mordant data and the simulations indicated that the fractional rate of passage during feeding was higher than that recorded in the postfeeding period. This suggests either that more than one fractional rate constant applies within a 24 h period, or that first-order kinetics do not apply. The estimates for k_d were considerably higher than those determined in dacron bags. Evaluation of the ability of the combined dacron bag and mordant techniques to estimate extent of digestion by comparison with in-vivo digestibility values indicated that the extent of digestion was underestimated. The predictions obtained from the rumen-emptying data were much closer to the in-vivo values.     

Dielectric properties of poly(α-methyl α-n-propyl-β-propiolactone)/poly(vinyl chloride) blends

The dielectric properties of miscible blends of poly(vinyl chloride) (PVC) and poly(α-methyl-α-n-propy-β-propiolae-tone) (PMPPL) have been investigated at different temperatures above and below T_g. The results were analyzed using the Cole-Cole representation and lead to the conclusion that this mixture does not exhibit micro-scale heterogeneities. Dielectric constant and dielectric loss master curves were constructed using the stress relaxation shift factors determined previously; the same shift factors could be used for the homopolymers and their blends. Similarities between the dielectric master curves and the stress relaxation master curves of PVC, PMPPL, and their blends, are also discussed.     

Cryoprocessing of cutting tool materials—a review

Cryoprocessing, a supplementary process to conventional heat treatment process, is the process of deep-freezing materials at cryogenic temperatures to enhance the mechanical and physical properties of materials being treated. The execution of cryoprocessing on cutting tool materials increases wear resistance, hardness, and dimensional stability and reduces tool consumption and down time for the machine tool set up, thus leading to cost reductions. The effects of cryoprocessing on tool steels and carbides, metallurgical aspects including reduced amount of retained austenite, precipitation of η-carbides, phase change in carbides, improvement in wear resistance, and applications are reviewed for manufacturing industry. Although it has been confirmed that cryogenic processing can improve the service life of tools, the degree of improvement experienced and the underlying mechanism remains ambiguous. The steps involved in cryoprocessing are critical enough to account for the significant incongruity in post-treated performance.     

Improving Operational Performance of Farmers Managed Distributary Canal using SIC Hydraulic Model

Operation of a secondary canal was recently transferred to the farmers’ organization (FO) under irrigation management transfer (IMT) programme. After modernization of Upper Swat Canal (USC) irrigation system, the water allowance was increased to operate the irrigation system more in demand responsive mode. The study of the existing operation of the canal revealed that most of the time the irrigation supplies exceed the demand and the farmers either over irrigate their fields or waste precious irrigation water. Operation and management aspect of the irrigation system play a pivotal role in overall water management practices. SIC hydrodynamic model was employed to evaluate the operational performance of the distributary. Different operational scenarios were investigated and quantified based on fixed frequency operation. Based on these results it is suggested to operate the distributary at 80–90% of the design discharge during May to July, and 75–90% of the design discharge from August to April to reduce water losses due to high water allowance.     

Prevalence on beef carcasses of Mycobacterium avium subsp. paratuberculosis DNA

Fifty samples were collected from each of skinned and dressed carcasses, from each of culled beef breeding cows and fed beef cattle <18 months old at two beef packing plants A and B, and from culled dairy cows at a packing plant C. The 450 samples were collected by swabbing an area of about 1000 cm2 in the anal region of each carcass. DNA extracted from each swab was tested for the IS900 and F57 sequences of the Mycobacterium avium subsp. paratuberculosis (MAP) genome by two stage, nested polymerase chain reaction (PCR) procedures. An internal amplification control (IAC) was detected in 45 or more of each group of 50 DNA preparations. IS900 and F57 were detected in some IAC-positive preparations from all and all but one of the groups of carcasses, respectively. Of the IAC-positive preparations in each group, between 6 and 54% were positive for IS900, and between 4 and 20% were positive for F57. When preparations were tested by single stage, quantitative PCR procedures, IS900 was detected in two samples but F57 was detected in none. The MAP DNA on carcasses was probably derived from small numbers of MAP from the environment that contaminated the animals' hides.     

The regulation of hazardous air pollutants under the Clean Air ActAmendments of 1990: effects on the Portland cement industry

Title III of the 1990 Clean Air Act Amendments (CAAA) addresses the control of hazardous air pollutants (HAPs) from major sources of air pollution in the United States. In the CAAA, Congress defined 189 compounds as hazardous air pollutants in need of additional control by the Environmental Protection Agency (EPA). Congress directed EPA to identify the major source categories which emit HAP's and to prepare regulations that would reduce and control future HAP emissions. This paper outlines the activities undertaken by EPA to regulate HAP emissions from Portland cement plants and the program developed by the Portland cement manufacturing industry to cope with Title III     

Microbiological effects of hand washing at a beef carcass-breaking facility

The hands of workers in the carcass-breaking facility at a beef packing plant were sampled by rinsing. Total aerobes, coliforms, and Escherichia coli were enumerated for each sample. The numbers of bacteria recovered from duplicate groups of 25 hand samples collected before and after hands were washed with an antibacterial gel, rinsed in a disinfectant solution, washed with the gel and rinsed with the disinfectant, or washed in the disinfectant for 20 s were similar for samples collected before work began after breaks. The numbers of bacteria recovered from samples collected before and after hands were washed with the antibacterial gel and rinsed in the disinfectant solution were similar for samples collected after work as well. However, the mean numbers of aerobes recovered from the four groups of hand samples after work were all >6.5 log CFU per hand, while 9 of the 10 corresponding values for groups of hand samples collected before work were <6.5 log CFU per hand; the total numbers of coliforms recovered from three groups of hand samples collected after work were >4 log CFU/25 hands, while 9 of the corresponding values for groups of hand samples collected before work were <4 log CFU/25 hands. The total numbers of E. coli recovered from all groups of hand samples collected after work were >3.5 log CFU/25 hands, while 9 of the corresponding values for groups of hand samples collected before work were <3 log CFU/25 hands. Thus, although washing and/or rinsing apparently did not reduce the numbers of bacteria on hands, fewer bacteria were recovered from hands before than after work.