Cold water detergency studies using radiolabeled soils

The effects of single and multiple washing and of resoiling-rewashing of cotton and synthetic fabrics have been studied in Tergotometer tests at various levels of temperature, detergent concentration and water hardness. The soiling mixture consisted of a seven component sebum tagged with tritium and carbon-14; in some tests gammaray emitting Kaolinite clay was also used. Linear primary alcohol ethoxylate (LAEO) and linear alkylbenzene sulfonate (LAS) were used for surfactant type comparisons. In single wash tests in both hot and cold water, LAEO was generally more effective than LAS in removing sebum. This was particularly noticeable at low product concentration where insufficient sodium tripolyphosphate was present to sequester the water hardness. A 1/1 blend of the two surfactants approached LAEO in performance. The nonpolar sebum fraction was more readily removed from Dacron or nylon in cold water; otherwise, detergency was generally better at high temperatures. In rewash tests, using labeled lube oil, cholesterol and clay, a progressive increase in soil removal was found during five wash cycles. The nonpolar lube oil component was the most difficult to remove from permanent press Dacron-cotton (PP), but was more readily removed from cotton. The more polar cholesterol and especially the clay were more easily removed from PP. LAEO gave better detergency both hot and cold than LAS, especially in hard water. On cotton swatches resoiled with sebum after each wash the residual sebum content was still increasing after five cycles. With PP in soft water, a steady state was reached after three to five cycles. Soil buildup was greater as hardness increased and as wash temperature and active matter concentration decreased, and was generally greater on cotton than on PP. LAEO allowed appreciably less soil buildup than did LAS especially at low concentration in hard water, indicating a reduced requirement for sodium tripolyphosphate. Presented before the AOCS Meeting, New Orleans, April 1970.     

Life safety systems in UK hospitals.

The type of systems covered here are not just speculative ideals but practical, working products installed in an ever increasing number of UK hospital establishments. Some sixty major hospitals have had systems supplied by my own company, very similar to those described, over the previous five year period. In addition, systems supplied by other competent companies show us that this trend is not just 'Technology for Technology's sake' but an important step forward in alarm management strategy.     

Rapid Analysis of Abietanes in Conifers

Diterpene resin acids are major constituents of conifer oleoresin and play important roles in tree defense against insects and microbial pathogens. The tricyclic C-20 carboxylic acids are generally classified into two groups, the abietanes and the pimaranes. The abietanes have conjugated double bonds and exhibit characteristic UV spectra. Here, we report the analysis of abietanes by reversed-phase high-performance liquid chromatography using multiwavelength detection to optimize quantification of underivatized abietic, neoabietic, palustric, levopimaric, and dehydroabietic acids. The utility of the method is demonstrated with methanol extracts of white spruce (Picea glauca) phloem, and representative concentrations are reported.     

Hydraulic/partitioning tracer tomography for DNAPL source zone characterization: small-scale sandbox experiments

Dense nonaqueous phase liquids (DNAPL) are prevalent at a large number of sites throughout the world. The variable release history, unstable flow, and geologic heterogeneity make the spatial distribution of DNAPLs complex. This causes difficulties in site remediation contributing to long-term groundwater contamination for decades to centuries. We present laboratory experiments to demonstrate the efficacy of Sequential Successive Linear Estimator (SSLE) algorithm that images DNAPL source zones. The algorithm relies on the fusion of hydraulic and partitioning tracer tomography (HPTT) to derive the best estimate of the K heterogeneity, DNAPL saturation (S(N)) distribution, and their uncertainty. The approach is nondestructive and can be applied repeatedly. Results from our laboratory experiments show that S(N) distributions compare favorably with DNAPL distributions observed in the sandbox but not so with local saturation estimates from core samples. We also found that the delineation of K heterogeneity can have a large impact on computed S(N) distributions emphasizing the importance of accurate delineation of hydraulic heterogeneity.     

Built-in self-test of the Macrolan chip

The implementation of self-test in the medium access controller chip for Macrolan, a fibre-optic, local area network, is described. The test style for 80% of the chip's combinational logic is quasiexhaustive testing. This approach, despite its apparent inefficiency in terms of the number of patterns used, gives considerable flexibility to the designer in arranging linear-feedback shift registers and so is easier to implement than some other techniques. The chip also uses a form of random-pattern test, not normally considered for memory testing, instead of a specialized pattern generator. Built-in self-test was implemented without using fault simulation or approximate testability measures     

Computerization in fabric detergency testing

An automated method is described which greatly speeds the calculation of fabric detergency test results. Laboratory determination of fabric detergency commonly involves replicated, bench scale washing of small pieces of cotton artificially soiled with various oil-carbon black mixtures. Reflectance measurements before and after washing give a measure of the amount of soil removed. Often, in a program involving several variables, thousands of reflectance measurements may be involved. By converting the electrical signal from the reflectometer to digital form, and feeding this value to a card punch, the reflectance values are systematically recorded on punched cards. Using an appropriate computer program, the reflectance changes for each test are calculated and tabulated, the saving in operator time is large and statistical examination of the data can be incorporated with the program. An example of the type of data output is given. Presented at the AOCS-AACC Joint Meeting, Washington, D.C., March 1968.