Knowledge-based risk evaluation during the offer calculation of customised products

The individualisation of products is a hybrid business strategy, which increases the competitiveness of production enterprises. But the inherent risks of order processing for customised products jeopardises the successful and economical implementation of this strategy: A potential risk exists within the calculation of the total costs due to incomplete information about the product and the production processes during the offer specification process as well as due to the temporal fluctuations of the prices and costs after the offer specification. This paper analyses the risks and existing methods regarding risks in offer calculation processes. The approach developed here proposes a knowledge-based system for the evaluation and configuration of risks during the order processing of individualised products. Based on a classification of the immanent risks, an evaluation method is introduced which is implemented in a knowledge-based system. The methods developed for calculation and interpretation allow for a good analysis of the risk situation of individualised products.     

The impact of temperature and gas-phase oxygen on kinetics of in situ ammonia removal in bioreactor landfill leachate

Microcosm experiments aimed at defining a rate equation that describes how different environmental conditions (i.e., gas-phase oxygen concentrations, temperature and ammonia concentration) may impact in situ ammonia removal were conducted. Results indicate that ammonia removal can readily occur at various gas-phase oxygen levels (between 0.7% and 100%) and over a range of temperatures (22, 35 and 45 degrees C). Slowest rates occurred with lower gas-phase oxygen concentrations. All rate data, except at 45 degrees C and 5% oxygen, fit well (r2=0.75) to a multiplicative Monod equation with terms describing the impact of oxygen, pH, temperature and ammonia concentration. All ammonia half-saturation values are relatively high when compared to those generally found in wastewater treatment, suggesting that the rate may be affected by the mass transfer of oxygen and/or ammonia. Additionally, as the temperature increases, the ammonia half-saturation value also increases. The multiplicative Monod model developed can be used to aid in designing and operating field-scale studies.     

Complex-coupled DFB lasers: advantages and drawbacks of gain andradiation loss grating

Two types of InGaAs-GaAs-AlGaAs complex-coupled distributed feedback laser structures grown by molecular beam epitaxy are compared. The first structure uses interrupted quantum wells (QW's) grown over a grating. Its properties strongly depend on the interface cleaning resulting in nonreproducible threshold current densities. The second structure includes three uniform QW's, the gain coupling being induced by the vertical radiation of the second order grating. This last structure has reproducible, low continuous wave threshold current densities (jth=300 A/cm²). The coupling strength and its origin are described for the two structures. Both structures have high mono-mode yield (>75%) and side-mode suppression ratios larger than 40 dB     

Investigating phase transitions and strength in single-crystal sapphire using shock–reshock loading techniques

This paper focuses on developing a technique that can probe phase transitions in ceramics and evaluating strength properties of single-crystal sapphire. High strength ceramics that undergo solid-to-solid polymorphic phase transitions can display a wide range of volume changes. Materials with large volumetric changes can be easily detected; however, materials demonstrating small volume changes, pose a different experimental problem. Because of the variety of diagnostics tools (for acquiring data), and differing interpretation of the data, materials that undergo small volume changes, make detection of transformation quite challenging. Different experimental test methods are needed to potentially allow detection and characterization of materials undergoing phase transitions with small volume changes. In addition, these results show that single-crystal sapphire has considerable strength loss at approximately 56 GPa on the Hugoniot. In this study, we report loading profile measurements in the form of particle velocity histories for single-crystal sapphire that is shocked to a given stress level directly or through multiple steps from a shocked state of 56 GPa. We probe the region of suggested phase transformations utilizing the simplest type of off-Hugoniot reshock loading. This also allows an assessment of shear strength in the shocked state of single-crystal c-axis sapphire. The present measurements show no evidence of a phase transition, but do suggest considerable strength loss in sapphire.     

The Mattis Dementia Rating Scale: normative data from 1,001 healthy volunteers

We administered the Mattis Dementia Rating Scale (MDRS) to 1,001 healthy volunteers, aged 50 to 80 years, randomly selected from our community. Multivariate regression analysis revealed educational level (p = 0.000004) and age (p = 0.00001), but no other sociodemographic or risk factors for stroke, to be significantly associated with the MDRS score. The age- and education-specific lowest quintile cutoff scores ranged from 140 in subjects aged 50 to 59 years with at least college experience to 130 in subjects aged 70 to 80 years with only 4 to 9 years of schooling. These percentile distributions obtained for decades of age and different levels of education should be useful reference values for clinicians and investigators when applying the MDRS to assess cognitive functioning.