The Effect of reaction by-products on the viscosities of sodium lauryl sulfate solutions

The fact that free oil and inorganic salts have pronounced influence on lauryl sulfate solution viscosity is a widely recognized but little studied phenomenon. This investigation of the effects of these materials has resulted in the derivation of a correlation function which relates the concentrations of the by-products to the solution viscosity. The contributions of the reaction by-products are found to be independent additive effects which contribute exponentially to solution viscosity. The results can be explained mechanistically in terms of the micellar model for surfactant solutions.     

Pediatric vascular trauma. Manifestations, management, and sequelae of extremity arterial injury in patients undergoing surgical treatment

Twenty pediatric patients with a mean age of 9.2 years exhibited 21 injuries to arteries of an extremity and underwent operation. Included were 12 iatrogenic injuries and nine non-iatrogenic penetrating injuries. Femoral, brachial, popliteal, radial, axillary, iliac, and tibial arteries were sites of vascular trauma. Long-term follow-up, averaging 36 months, was possible in 14 patients. Postoperative scanograms, digital impedance plethysmographic studies, and bone age roentgenograms were routinely obtained. Limb length disparities greater than 5 mm, extremity blood pressure differentials greater than 10 mm Hg, and bone age retardation were encountered. Proper treatment of pediatric patients with acute arterial injuries of an extremity requires early operative intervention and continuous postoperative follow-up during years of active growth. If chronic arterial insufficiency ensues, arteriographic studies should be obtained and arterial reconstruction undertaken.     

The scaling of fire resistance problems

Heat conduction scaling relations are given, particularly some relating time and dimension, and empirical findings are used to permit their extension to fire resistance problems, including those relating to concrete-encased steel columns. The merit of scaling, apart from its simplicity, is that it does not require a knowledge of the thermal properties of the materials involved and that it takes into account variation of thermal properties with temperature and many of the effects of moisture.     

Energetics of triosephosphate isomerase: the nature of the proton transfer between the catalytic base and solvent water

The isomerization of specifically deuterium-labeled [1(R)-2H5dihydroxyacetone phosphate to D-glyceraldehyde 3-phosphate, catalyzed by the enzyme triosephosphate isomerase, has been studied. It is shown that the extent of transfer of the 2H label from the substrate to the product D-glyceraldehyde 3-phosphate is (after complete reaction) the same as that of the corresponding transfer of 3H. The absence of an isotope effect shows that the exchange process of the tstopically labeled enzyme carboxyl group, -COOL H2O leads to -COOH + LOH, does not tnvolve a rate-limiting transition state in which L is the flight. Possible modes for the nature of the ionization of -COOL in 1H2O are discussed.     

Interworking between SDH and OTN-Based Transport Networks

This paper describes methods by which an existing SDH-based transport network can evolve towards one based on the emerging optical transport network, the OTN. Depending upon the chosen method of interworking, a number of evolutionary paths are possible. New SDH mappings are proposed that allow the construction of modems for the transport of OTN entities on SDH networks during possible transition phases. Transport of STM-N frames over SDH path layers is also considered for the provision of manageable, transparent STM-N services.     

Confidence intervals and sample size determination for Cpm

The capability index, C_pm, sometimes called the Taguchi index, has the desirable characteristic of being sensitive to both dispersion and deviation of the process average from the engineering target. As a result, the proposed estimators of C_pm have a sampling distribution that is dependent on the non‐central chi‐square distribution. Hence, constructing confidence intervals, performing hypothesis testing or estimating sample size requirements necessitates manipulation of a rather complex functional expression, typically beyond the capabilities of practitioners who need readily available tools. Here, a simple graphical procedure is proposed and illustrated for obtaining exact confidence intervals for C_pm. The graphical procedure allows the user to simply enter the graph with an estimate of the index and a value of the non‐centrality parameter for a given sample size to arrive at end‐points of 90%, 95% or 99% one‐sided or two‐sided confidence intervals. Detailed tables are also provided to assist the user for a wider range of sample values and sample sizes. In addition, a procedure is also presented for determining the minimum sample size required for attaining a pre‐specified level of accuracy of the C_pm. Extensive tables are provided for the user with a simple example illustrating the facility of the technique. Copyright © 2001 John Wiley & Sons, Ltd.     

Effects of high-pressure high-temperature treatment on the thermoelectric properties of PbTe

Changes in the thermoelectric properties of nominally undoped stoichiometric PbTe caused by high-pressure high-temperature (HPHT) treatment near 6.5 GPa and 900 °C are reported. Comparison of the electrical resistivity, thermopower, and thermal conductivity suggest that the carrier concentration and lattice defect density are decreased by HPHT treatment. Annealing the treated samples at intermediate temperatures (500–600 °C) reversed the changes. These observations are consistent with Pb vacancies being “squeezed out” by the applied pressure, and subsequently reintroduced by annealing.     

先进的棒材生产设备—3—辊减径定径轧机组

介绍KOKS/DANELI公司先进的3 -辊RSB棒线材轧机的特点,以及目前世界上棒线材生产工艺中最具特色的轧辊系列、C -模块传动、快速换辊和机架更换的摇控系统,低温精轧和低成本、高回报率的特点等进行了论述。     

Linking particle properties to dense suspension extrusion flow characteristics using discrete element simulations

Extrusion is a widely used process for forming suspensions and pastes into designed shapes, and is central to the manufacture of many products. In this article, the extrusion through a square‐entry die of non‐Brownian spheres suspended in Newtonian fluid is investigated using discrete element simulations, capturing individual particle‐particle contacts and hydrodynamic interactions. The simulations reveal inhomogeneous velocity and stress distributions, originating in the inherent microstructure formed by the constituent particles. Such features are shown to be relevant to generic paste extrusion behavior, such as extrudate swell. The pressure drop across the extruder is correlated with the extrudate flow rate, with the empirical fitting parameters being linked directly to particle properties such as surface friction, and processing conditions such as extruder wall roughness. Our model and results bring recent advances in suspension rheology into an industrial setting, laying foundations for future model development, predictive paste formulation and extrusion design. © 2016 American Institute of Chemical Engineers AIChE J, 63: 3069–3082, 2017