The role of algorithm and result comprehensibility of automated scheduling on complacency

Several studies have stressed that even expert operators who are aware of a machine's limits could adopt its proposals without questioning them (i.e., the complacency phenomenon). In production scheduling for manufacturing, this is a significant problem, as it is often suggested that the machine be allowed to build the production schedule, confining the human role to that of rescheduling. This article evaluates the characteristics of scheduling algorithms on human rescheduling performance, the quality of which was related to complacency. It is suggested that scheduling algorithms be characterized as having result comprehensibility (the result respects the scheduler's expectations in terms of the discourse rules of the information display) or algorithm comprehensibility (the complexity of the algorithm hides some important constraints). The findings stress, on the one hand, that result comprehensibility is necessary to achieve good production performance and to limit complacency. On the other hand, algorithm comprehensibility leads to poor performance due to the very high cost of understanding the algorithm. © 2008 Wiley Periodicals, Inc.     

Co‐composting an animal fatty‐proteinaceous waste with a solid lignocellulosic by‐product from the olive oil industry (‘alperujo’)

BACKGROUND: The production of biodegradable wastes and their disposal cause a major financial problem in many industrial activities. Co‐composting was thought to be a feasible alternative for disposing of a strongly alkaline waste from the pharmaceutical industry (AW), mainly consisting of animal fats and partially hydrolysed proteins in a stable emulsion. The AW was added gradually, during the early phase of the composting process, to a substrate made up of ‘alperujo’ (AL), the wet, lignocellulosic, solid by‐product of the olive oil industry, and fresh horse manure, which was added to improve the physical structure of the composting substrate. RESULTS: The addition of AW reduced organic matter degradation during composting, enriched the amount of organic compounds in the water‐ and alkali‐soluble fractions and increased mineral salt contents. Thus, significantly higher electrical conductivity, humification indices and contents of organic matter, P, K and Na were recorded in the end‐composts resulting from AW treatments. However, the application of one AW‐based compost led to soil N immobilisation, as revealed by an incubation experiment, which must be considered in order to avoid potential N starvation in the short term. CONCLUSION: According to these results, composting can be used as a disposal alternative for AW, leading to end‐products with potential uses as organic amendments or fertilisers for agricultural systems. In addition, these composts could be used to produce alternative liquid organic fertilisers, based on the extraction of their humic‐like fraction. Copyright © 2009 Society of Chemical Industry     

Wool bleaching with reducing agents in the presence of sodium lauryl sulphate. Part 5 — bleaching with sodium bisulphite

Wool bleaching with sodium bisulphite in the presence of sodium lauryl sulphate has been shown to improve wool whiteness by four Berger units. A 25% decrease in cysteine content is also obtained as a consequence of the protective action of the surfactant on the keratin's disulphide linkage.     

The Influence of Ionic Surface–active Agents on the Dyeing of Hercosett Wool with α–Bromoacrylamide Dyes

The behaviour of two surface–active agents (anionic and cationic) in the dyeing of Hercosett wool with reactive dyes of the α–bromoacry/amide type has been studied. The influence of pH, concentration of dye and surface–active agent, temperature and time on the percentage of the dye adsorbed and reacted is studied. Due to the complexity of this subject, a central rotatable plan of five variables has been used. The results found are represented in three–dimensional graphs, and are examined through the possible mechanisms that operate in the dyeing process, considering the nature of the anionic and cationic agents used.     

Application of a micromechanical model of three phases to estimating the porosity of mortar by ultrasound

Among the factors that affect the durability of cement-based materials, porosity is important due to its role in transporting substances inside the material. Porosity can be determined using destructive testing methods, but the civil construction industry needs a nondestructive method for the estimation of the volume of pores in cement-based materials to evaluate the deterioration process.In this investigation, a micromechanical model of three phases developed in a previous paper is used to estimate the porosity of a series of mortar samples. The proposed model takes into account the microstructural characteristics and elastic properties of the constituent phases. In a first stage, the model is used to predict the influence of both the volume fraction of sand and pores and the elastic constants of the matrix and the sand on the ultrasonic velocity. Next, experimental measurements are made on a series of mortar samples of varying water/cement ratio, cement type and sand concentration, with the results used to demonstrate that porosity can be estimated using the proposed nondestructive method.     

Dyeing wool packages with continuous dosage of dye

Integration dyeing of wool packages by Lanaset dyes has been examined. Absorption kinetics were found to be governed by the Cegarra-Puente equation, giving an apparent activation energy of 104 kJ/mol. The levelness obtained by integration dyeing at various temperatures and dye concentrations were compared with that obtained by following the standard method. Similar values were observed in both systems.     

Optimization of the Conventional Bleaching of Wool with Hydrogen Peroxide

The individual and combined influence on the bleaching of wool of the concentration of hydrogen peroxide, temperature and time of treatment have been studied, using a rotatable central design of experiments in which the values of the above variables covered the values used in industry. Mathematical treatment of the values of the optical, chemical and mechanical parameters has enabled equations to be derived, from which the value of any parameter can be computed when the values of the variables are within the range of the plan of experiments, resulting in a good agreement being obtained between experimental and calculated values. Use of these equations facilitates optimization of the process of wool bleaching, and bleaching conditions leading to the whitest wool have been suggested for an allowable chemical degradation (alkali solubilities of 25%and 30%). More severe conditions of bleaching do not necessarily produce a whiter wool, but cause greater chemical and mechanical degradation of the fibre. An excellent linear correlation has been found between the chemical parameters modified by the bleaching operation and between these and the wet tensile strength of the fibre.     

Use of 2,4-Dihydroxybenzophenone-2‘-ammonium Sulphonate to Prevent the Yellowing of Wool by Ultraviolet Radiation

The use of 2,4-dihydroxybenzophenone-2′-ammonium sulphonate (das) to prevent the yellowing of wool by ultraviolet radiation is discussed. The optimum conditions of application of this absorber to wool have been determined. The Yellowness Index, a measure of the degree of yellowing, was used to determine the effect of the concentration of das on its protective action against ultraviolet radiation. Exposure in a Xenotest apparatus indicated that initially bleaching occurred, followed by yellowing, which decreased with increase in the concentration of das. The washing and dry-cleaning fastness properties of das on wool were assessed and the effect of dye on these properties was also determined, das has poor washing fastness, but this can be improved by mordanting the wool before treatment with das. This absorber does not significantly improve the light fastness of acid dyes on wool.     

Influence of automation mode use on selection rates and subjective assessment over time

Cognition, Technology & Work - The main objective of the current contribution was to investigate human–machine cooperation over time. Participants were asked to choose repeatedly between...     

Some Observations on Continuous Pressure Steaming in Dyeing of Polyester Tow and Wool Sliver

Work carried out with a laboratory-scale and a bulk-scale unit of the Segard-Serracant tunnel for dyeing combed wool tops and polyester fibre tow is described. A new system for the continuous dyeing of wool with black chrome dyes is also described, together with its effect on the properties of the wool. The fastness properties of the resultant dyeings are given. A system for the dyeing of polyester fibre tow is outlined. The service—water, steam and electricity—and labour requirements of this system are discussed.