The European Union integrated pollution prevention and control directive and its impact on the wool textile industry

Council directive 96/61/EC on integrated pollution prevention and control was agreed by the Council of the European Union on 24 September 1996. It will have far reaching effects on industrial installations throughout the European Union. This paper summarises the directive's provisions and attempts to predict its impact on wool textile wet processors. The actions being taken by trade associations to ensure that the guidelines are fair and reasonable are also reviewed.     

Mechanically Enhanced Reactivity of Silicon for the Formation of Silicon Nitride Composites

The chemical reactivity of silicon can be enhanced by mechanical activation. Ball milling elemental silicon powders with a small amount of carbon addition at ambient temperature has resulted in an enhanced nitridation of silicon at high temperatures. In comparison with powder mixtures without milling, the nitridation process at 1250°C has been accelerated by a factor of 9 and 23 by milling powder mixtures in N₂ and NH₃, respectively, before nitridation. The enhanced nitridation process for powders milled in N₂ is primarily attributed to the mechanical activation, whereas for powders milled in NH₃, the trapped nitrogen within the powder mixtures during milling also contributes to the enhanced nitridation process, in addition to the effect of the mechanical activation.     

A parametric study of a horizontal rotating fluidized bed using slotted and sintered metal cylindrical gas distributors

The pressure drop in a horizontal rotating fluidized bed was measured using slotted and sintered metal cylindrical gas distributors as a function of rotating speed, gas velocity and bed thickness. Experiments were conducted using polydisperse alumina particles and nearly monodisperse glass beads. The pressure drop for the slotted distributor exhibited a much larger pressure overshoot at incipient fluidization than the sintered metal distributor. This behavior was also studied using high-resolution photography. Physically consistent explanations are presented for the observed phenomena. The experimental results are compared to theoretical models available in the literature.     

Trajectories leading to school-age conduct problems.

The present study applied a semiparametric mixture model to a sample of 284 low-income boys to model developmental trajectories of overt conduct problems from ages 2 to 8. As in research on older children, 4 developmental trajectories were identified: a persistent problem trajectory, a high-level desister trajectory, a moderate-level desister trajectory, and a persistent low trajectory. Follow-up analyses indicated that initially high and low groups were differentiated in early childhood by high child fearlessness and elevated maternal depressive symptomatology. Persistent problem and high desister trajectories were differentiated by high child fearlessness and maternal rejecting parenting. The implications of the results for early intervention research are discussed, with an emphasis on the identification of at-risk parent-child dyads. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socioeconomic status, neighborhood social conditions, and neural tube defects

OBJECTIVES: This study evaluated the contributions of lower socioeconomic status (SES) and neighborhood socioeconomic characteristics to neural tube defect etiology. The influence of additional factors, including periconceptional multivitamin use and race/ethnicity, was also explored. METHODS: Data derived from a case-control study of California pregnancies from 1989 to 1991. Mothers of 538 (87.8% of eligible) case infants/fetuses with neural tube defects and mothers of 539 (88.2%) nonmalformed infants were interviewed about their SES. Reported addresses were linked to 1990 US census information to characterize neighborhoods. RESULTS: Twofold elevated risks were observed for several SES indicators. Risks were somewhat confounded by vitamin use, race/ethnicity, age, body mass index, and fever but remained elevated after adjustment. A risk gradient was seen with increasing number of lower SES indicators. Women with 1 to 3 and 4 to 6 lower SES indicators had adjusted odds ratios of 1.6 (1.1-2.2) and 3.2 (1.9-5.4), respectively, compared with women with no lower SES indicators. CONCLUSIONS: Both lower SES and residence in a SES-lower neighborhood increased the risk of an neural tube defect-affected pregnancy, with risks increasing across a gradient of SES indicators.     

Property-composition relationships for diesel and kerosene fuels

A range of 18 diesel fuels and 21 kerosene fuels from mainly Australian petroleum and synthetic fuel sources, including coal, shale and peat, was investigated. Compositional details were defined as the weight per cent abundances of n-alkanes, branched plus cyclic saturates, single-ring aromatics, doublering aromatics and polynuclear aromatics, using both h.p.l.c. and ¹³C n.m.r. techniques. Relationships between fuel composition and a range of fuel properties were sought. Simple linear relationships between property values and compositional data were used. Explicit correlative expressions were derived using multiple linear regression analysis, with the coefficient of multiple determination, R², indicating the quality of the fit between observed and calculated property values. In most cases good correlations were achieved. For diesels the properties investigated, with R² values in parentheses, were: inverse specific gravity (0.99); ¹³C n.m.r. aromaticity (0.99); ¹H n.m.r. aromaticity (0.88); cetane index (0.97); aniline point (0.96); diesel index (0.98); and FIA-measured aromatics content (0.77). For kerosenes the properties, with R² values in parentheses, were: ¹³C n.m.r. aromaticity (0.98); ¹H n.m.r. aromaticity (0.97); smoke point (0.88); and FIA-measured aromatics content (0.94). The results are shown to be of value in assessing the potential and limitations of hydrotreating as a process for upgrading synfuels.     

Integral-based parameter identification for long-term dynamic verification of a glucose-insulin system model

Hyperglycaemia in critically ill patients increases the risk of further complications and mortality. This paper introduces a model capable of capturing the essential glucose and insulin kinetics in patients from retrospective data gathered in an intensive care unit (ICU). The model uses two time-varying patient specific parameters for glucose effectiveness and insulin sensitivity. The model is mathematically reformulated in terms of integrals to enable a novel method for identification of patient specific parameters. The method was tested on long-term blood glucose recordings from 17 ICU patients, producing 4% average error, which is within the sensor error. One-hour forward predictions of blood glucose data proved acceptable with an error of 2-11%. All identified parameter values were within reported physiological ranges. The parameter identification method is more accurate and significantly faster computationally than commonly used non-linear, non-convex methods. These results verify the model's ability to capture long-term observed glucose-insulin dynamics in hyperglycemic ICU patients, as well as the fitting method developed. Applications of the model and parameter identification method for automated control of blood glucose and medical decision support are discussed.     

T-cell activation: interplay at the interface

Recent studies have shown that, when a T cell interacts with a cognate antigen-presenting cell, an organized adhesive contact is formed between the two cells by a process which involves the dynamic, three-dimensional redistribution of entire signaling assemblies.     

Stresses in bulk solids in wedge hoppers: A flexible formulation of the co-ordinate specific, Lame-Maxwell equations for circular arc, principal stress systems

A 2-D model of stress distribution within bulk solids, with circular arc principal stress orientation, in a wedge hopper was developed in a previous paper [Matchett, O'Neill, & Shaw, Stress distributions in 2-dimensional, wedge hoppers with circular arc stress orientation — a co-ordinate-specific Lamé-Maxwell model, Powder Technology, 187(2008) 298-306]. This model worked in an orthogonal, curvilinear co-ordinate system co-incident with the principal stress trajectories: (x − ψ_o) space.This paper presents an equivalent model in (x − ε) space. This allows backward numerical integration of the force balance equations, enabling surface and wall boundary conditions to be modelled. This was not possible in the original model.The equations are first-order, and boundary conditions can only be specified at single surfaces. Thus, if a stable, cohesive arch is proposed, the surface overpressure is determined by the model. Calculated overpressures have reasonable physical values.The present model was integrated backwards from the surface downwards and it was found that the integration was very sensitive to the surface overpressure stresses.Likewise, wall boundary conditions were specified with backwards integration in ε.The minimum outlet for flow was calculated from the model and compared with the experimental data of Berry et al. Wall normal stresses in a wedge hopper from Schulze and Schwedes were also compared to model predictions. In both cases there was reasonable agreement between measurements and model predictions.