Iron and its dilute substitutional solid solutions

The new results of an extensive study of the effects of alloying elements upon the properties of iron are presented, including lattice parameters, elastic constants, the effect of temperature on strength, solid solution strengthening and softening, work hardening, strain aging, hot working and toughness.     

A Novel and Comprehensive Final Finishing Process for Worsted and Related Fabrics

In conventional processing, handle, thickness, lustre, dimensional stability, etc., are largely determined by the three final finishing processes known as pressing (hydraulic or rotary), blowing and high-temperature decatising (the last being essentially a ‘setting’ process). The significant changes in fabric properties which are brought about in these three industrial procedures are briefly mentioned, and emphasis is given to the results that can be achieved in respect of fabric compression and subsequent recovery. There are serious limitations to the extent to which a high degree of compression can be permanently ‘set’ into fabric when it is in roll form, and also to the permanence of finish that can be achieved by continuous blowing or pressing. The principles underlying the proposed new process are then described. Data are given for the compression and recovery characteristics obtained with this process, and these are compared with the results of conventional methods. The paper consists of an account of the development of a machine for industrial production, indicating some of the problems that have had to be solved, and ends with an assessment of its anticipated commercial advantages.     

Isolation,characterization and activity of phytotoxic compounds from quackgrass [Agropyron repens (L.)Beauv.]

Previous experiments showed that legumes grown in the presence of living or herbicidally treated quackgrass residues or extracts exhibited reduced seedling root and shoot growth and decreased nodulation and nitrogen fixation. Aqueous extracts of quackgrass shoots were most inhibitory to plant growth. Upon sequential partitioning of an aqueous extract of quackgrass shoots, the ether extract possessed the most activity and caused 50% reductions in radicle elongation of eight crop and weed species at concentrations of less than 240 g/ml (small-seeded species) and 1000 g/ml (large-seeded species). Snapbeans (Phaseolus vulgaris L. Bush Blue Lake) grown aseptically in agar containing an ether extract at 100 and 200 g/ml exhibited severe root browning, lack of root hair formation, and a two- to three-fold reduction in root and shoot dry weights. The ether extract of quackgrass shoots had no inhibitory effect on the growth of fourRhizobium species in Petri dishes or two species in broth culture. Inhibitors present in the ether extract may influence the legumeRhizobium symbiosis indirectly by reducing legume root growth and root hair formation. The ether extract of quackgrass shoots was separated using high-pressure liquid, thin-layer, and liquid column chromatography in an attempt to isolate and identify the inhibitors responsible for the inhibition of seedling growth. Two closely related flavonoid inhibitors were isolated from the ether extract. One was identified as 5,7,4-trihydroxy-3,5-dimethoxyflavone (tricin). Both flavonoids caused 50% inhibition of radicle elongation in cress (Lepidium sativum L. Burpee curly) seeds at concentrations of less than 125 g/ml. Both flavonoids were found in ether extracts of quackgrass shoots and rhizomes, but the largest amounts of both compounds occurred in quackgrass shoots collected from the field.Journal article No. 11887 of the Michigan Agricultural Experiment Station.     

Gwinnett County: Changing its service delivery in response to population growth.

Describes the development of a comprehensive management system in the Gwinnett County (Georgia) psychological services unit. The unit altered its service delivery model from one with a primary emphasis on psychoeducational assessment to one focusing on consultation and preventative services. Adherence to the American Psychological Association's specialty guidelines for provision of psychological services in schools is described. This management system enabled the unit to provide quality services to a maximal number of students, parents, and educators, despite the inevitable constraints placed on delivery of services by their growing population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concentration and preliminary characterization of a chemical attractant of the oyster drill,Urosalpinx cinerea

Predatory muricid gastropods,Urosalpinx cinerea, respond to specific chemical stimuli by creeping upcurrent. Attractant substances originate from living barnacles. Newly hatched snails have no prior predatory experience but respond strongly to attractants. We report here methods for rapidly extracting and desalting attractants from seawater. Attractants from living barnacles are relatively large, at least partially proteinaceous, heat-stable molecules (> 1000 but < 10000 dallons) that adsorb onto Amberlite XAD-7, a polyacrylate water purification resin, at neutral pH. Attractants remain adsorbed to the resin during a wash with deionized water and can be eluted in a small volume with 100% methanol. Attractant substances are effective in the bioassay in g/liter concentrations (octa- to nanomolar range). Potency is destroyed by nonspecific proteases (carboxy-peptidase and pronase) but not by trypsin. Attractant is not sequestered within barnacles.     

Development of a rare cell fractionation device: application for cancer detection

Isolating rare cells from biological fluids including whole blood or bone marrow is an interesting biological problem. Characterization of a few metastatic cells from cancer patients for further study is desirable for prognosis/diagnosis. Traditional methods have not proven adequate, due to the compositional complexity of blood, with its large numbers of cell types. To separate individual cells based on their mechanical characteristics, we have developed a series of massively parallel microfabricated sieving device. These devices were constructed with four successively narrower regions of channels numbering /spl sim/1800 per region. As cells traversed the device, they encountered each region and stopped at a gap width that prohibited passage due to their size. Cultured neuroblastoma cells, when mixed with whole blood and applied to the device, were retained in the 10-/spl mu/m-wide by 20-/spl mu/m-deep channels. All other cells migrated to the output. A derivative of the same device was utilized to characterize migration of whole blood. Adult white blood cells were retained at the 2.5-/spl mu/m-wide by 5-/spl mu/m-deep channels, while red blood cells passed through these channels. Devices designed to capture rare cells in peripheral circulation for downstream analysis will provide an important tool for diagnosis and treatment.     

Intra-aggregate mass transport-limited bioavailability of polycyclic aromatic hydrocarbons to Mycobacterium strain PC01

Biodegradation kinetics for three- and four-ring PAHs by Mycobacterium sp. strain PC01 were measured in whole and density-fractionated estuarine sediments and in a system without intra-aggregate mass transport limitations. The biokinetic data in the systems with and without intra-aggregate mass transport limitations were compared with abiotic PAH desorption kinetics. The results indicate that intra-aggregate mass transport limitations, and not the intrinsic bacterial PAH utilization capacity, were most important in controlling the rate of biodegradation of sediment-sorbed PAHs. Achievable extent of biodegradation could be predicted by the independently measured traction of desorbable PAHs in the fast-diffusion regime of a two-domain intra-aggregate mass transport model. A closed-form mathematical model was developed to describe sediment-pore water partitioning and rapid aqueous-phase diffusion of PAHs through the macropore and mesopore network of sediment aggregates, followed by first-order biodegradation of desorbed PAHs in the bulk aqueous domain. The model effectively predicted independent biodegradation kinetics of PAHs field-aged in two estuarine sediments. Despite low aqueous solubility of PAHs, macropore and mesopore diffusion may be an important mechanism controlling intra-aggregate mass transport and bioavailability of the most readily and extensively desorbed PAHs in sediments.