Validation of the integrated upward–horizontal–downward wicking test for providing intensive properties of textile fabrics

Traditional wicking tests provide information that is specific to the test fluid, apparatus, and conditions. As a result, this information cannot be used to make predictions about wicking rates beyond the respective test parameters. In contrast, a new upward–horizontal–downward (UHD) wicking test has been presented that provides intensive properties of fabrics in the form of permeability (k) and effective capillary radius (R _c) as functions of saturation (S). The UHD test was developed using water as the test fluid. If the k–S–R _c relationships are truly intrinsic to a given fabric, then they should not depend on the test fluid. Here, we conducted the UHD test on a knit fabric using three different test fluids characterized by different surface tensions, densities, and viscosities: dodecane, tetradecane, and hexadecane. All fluids fall on the same k vs. S and k vs. R _c curves, proving that these curves are intrinsic characteristics of the fabric. We then used the k–S–R _c properties to successfully predict the in-plane horizontal and downward wicking rates of two different fluids, octanol and water, in the fabric. These results validate the UHD wicking test as a method for providing intensive properties of textile fabrics which can then be used for predicting wicking rates.     

Multivariable norm optimal iterative learning control with auxiliary optimisation

The paper describes a substantial extension of norm optimal iterative learning control (NOILC) that permits tracking of a class of finite dimensional reference signals whilst simultaneously converging to the solution of a constrained quadratic optimisation problem. The theory is presented in a general functional analytical framework using operators between chosen real Hilbert spaces. This is applied to solve problems in continuous time where tracking is only required at selected intermediate points of the time interval but, simultaneously, the solution is required to minimise a specified quadratic objective function of the input signals and chosen auxiliary (state) variables. Applications to the discrete time case, including the case of multi-rate sampling, are also summarised. The algorithms are motivated by practical need and provide a methodology for reducing undesirable effects such as payload spillage, vibration tendencies and actuator wear whilst maintaining the desired tracking accuracy necessary for task completion. Solutions in terms of NOILC methodologies involving both feedforward and feedback components offer the possibilities of greater robustness than purely feedforward actions. Results describing the inherent robustness of the feedforward implementation are presented and the work is illustrated by experimental results from a robotic manipulator.     

Parameter optimization in iterative learning control

In this paper parameter optimization through a quadratic performance index is introduced as a method to establish a new iterative learning control law. With this new algorithm, monotonic convergence of the error to zero is guaranteed if the original system is a discrete-time LTI system and it satisfies a positivity condition. If the original system is not positive, two methods are derived to make the system positive. The effect of the choice of weighting parameters in the performance index on convergence rate is analysed. As a result adaptive weights are introduced as a method to improve the convergence properties of the algorithm. A high-order version of the algorithm is also derived and its convergence analysed. The theoretical findings in this paper are highlighted with simulations.     

Modeling Resuspension in a Dynamic Water Supply Reservoir

Enhancements to the two-dimensional lake and reservoir water quality model W2Tn to simulate the effects of currents and waves on sediment resuspension and turbidity are described. Bed stress attributable to currents was computed by the hydrothermal component of W2Tn, whereas a surface wave component was added to W2Tn to determine bed stress owing to waves. Resuspension flux is computed from bed stress and is included as a source of turbidity to the water column. The model is tested through application to Schoharie Reservoir, a drinking water supply that experiences episodes of elevated turbidity caused by runoff events and exacerbated by drawdown. Model predictions of bed stress attributed to currents are validated by using measurements obtained from acoustic Doppler instrumentation. The surface wave component of the model is established on a framework that has been previously validated for Schoharie Reservoir. Testing of the enhanced turbidity component of W2Tn was completed for a 3.5-year period of historical observations, which included a number of runoff events covering a range of severity and variations in reservoir drawdown. The enhanced model performed well in simulating observed conditions in the water column. The resuspension mechanism made a significant contribution to the predicted turbidity during periods of reservoir drawdown and during a severe runoff event. The model also performed well in simulating the observed turbidity of the drinking water withdrawal. Resuspension of particles contributing to turbidity was largely attributable to reservoir currents with surface wave-induced resuspension playing a smaller role. The potential application of this model to other water bodies and water quality issues is discussed.     

Design of superhydrophobic ultraoleophobic NyCo

The apparent contact angles of dodecane droplets deposited on a 50:50 nylon:cotton blended woven fabric (NyCo) were measured, and the characteristics required for an ultraoleophobic surface were described. The metastable Cassie–Baxter model, a transition status from the original Cassie–Baxter model to the Wenzel model, was investigated to design ultraoleophobic surfaces and to understand the wetting behavior of such surfaces. Using chemical and geometrical modifications of NyCo, a surface having contact angles to dodecane of greater than 150° and water contact angles of greater than 165° has been prepared. Good agreement between the predicted and measured contact angles was obtained. Developing a superhydrophobic ultraoleophobic material has been achieved by two criteria: a low-surface-energy and a properly designed surface morphology.     

Autoimmune polyglandular failure associated with malabsorption and gastric carcinoid tumour

A 21-year-old female with autoimmune polyglandular failure (APG) manifested by insulin-dependent diabetes mellitus (IDDM), hypothyroidism and pernicious anaemia developed severe malabsorption due to exocrine pancreatic insufficiency. Supplemental pancreatic enzymes resulted in marked improvement of steatorrhea. There was also an incidental finding of gastric carcinoid tumour. We identified only 13 other patients in our institution with either type 2 or 3 APG, one of which had significant steatorrhoea. Another patient with IDDM, hypothyroidism and pernicious anaemia had an asymptomatic gastric carcinoid tumour. The possible mechanisms for malabsorption in APG are discussed.     

Fluoridated etching on orthodontic bonding

To evaluate the impact of the 1993 expansion of the acquired immunodeficiency syndrome (AIDS) surveillance definition on reporting of persons with no HIV risk exposure information, we compared persons reported with and without risk in 1992 and 1993. The expanded case definition resulted in a large increase in both the number of persons reported with risk (121% increase) and without risk (167% increase). The changes in demographic characteristics for each group were similar from 1992 to 1993. Persons reported based on immunologic criteria were more likely and persons with pulmonary tuberculosis (PTB) less likely than those meeting the pre-1993 definition criteria to be reported with risk. Many persons with PTB were retrospectively identified from tuberculosis registries that do not systematically include HIV risk information. Ascertainment of risk information continues to be an essential part of AIDS surveillance with >90% of reports including risk exposure.