Degradation state estimation

Chromatographic Analysis and Total Luminescence Intensity as Tools for Early Degradation Detection and Degradation State Estimation... 

Chemical electrical optimisation Predictive analysis of electrode and membrane degradation or anomalies Estimate of electrode state Estimate of membrane state... 

Indicator Products and Chromatographic Fingerprinting New Tools for Degradation State and Lifetime Estimation... 

At each transition the failure rates are updated to values that depend on the degradation states reached by the components. A weight is accumulated in the counters associated to the discrete bins in which the macro-states of the components are OFF", equal to the fraction of time in which the components are unavailable in the bin. After performing all the Monte Carlo histories, the content of each counter divided by the time interval Dt and by the number of histories gives an estimate of the mean unavailability of the component in that counter time. A similar accumulation is done for the counters devoted to the recording of the availability state of the system. 

ABSTRACT This paper illustrates the main features of the MUlti-STAte DEgradation Process analysis Tool (MUSTADEPT), a new software tool which allows quantitatively describing the evolution of the degradation process of an industrial equipment, modeled as a discrete-state transport process. Two different, complementary approaches are offered. One is based on statistics, specifically the Maximum Likelihood Estimation (MLE) technique to estimate the parameters of the degradation process model and the Fisher Information Matrix for evaluating the uncertainty associated to the estimates. The other approach relies on information elicited from experts and describes and propagates the associated uncertainty within the DSTE framework. In both cases, the probabilities that the component occupies the different degradation states over time are estimated with the associated uncertainties. 

Statistical , which exploits the available dataset containing left censored data to estimate the parameters of the stochastic transitions between the degradation states, and the associated uncertainties. 

MUSTADEPT provides in output the probability with which the SCC occupies the different degradation states over time, and the uncertainty associated to this evaluation. In particular, such uncertainty encodes both aleatory (i.e., inherent to the SSC stochastic behaviors) and epistemic (i.e., due to the lack of precise knowledge of the model parameters and the Monte Carlo estimation) contributions. 

For each time instant, the specific solutions of the DSTE approach give the bounds of the probabilities of finding the SSC in the 4 degradation states, and the associated uncertainties, described in terms of Belief and Plausibility functions. These encompass both epistemic and aleatory uncertainties and, roughly speaking, can be regarded as the lower and upper bounds, respectively, of all the possible CDFs encoded by the imprecise estimations provided by the experts on the model parameters. 

Develop and implement a technique for propagating the estimated uncertainties (confidence intervals) onto the probabilities of occupying the degradation states over time ... 

Eq. (10) allows us relating t with the degradation states recorded on the f-th machine at time t. Data in the original database allows us to calculate the ML estimators 0 = 4,1 , of 0= y, 7, these are normally distributed random variables with N(P,ap) and respectively, as shown in... 

The solid-state NMR technique may also be used in cellulose derivatives to follow the degree of substitution and degradation of the chain e.g. as found for cellulose nitrate 16). Investigations on the composition of copolymers may also been done as examplared by celluloseacetate-butyrate given in Fig. 6, 20). Here, owing to relaxation differences the spectra cannot be used for elementary analyses, but for estimating the relative number of the components. 

The subsequent fate of the assimilated carbon depends on which biomass constituent the atom enters. Leaves, twigs, and the like enter litterfall, and decompose and recycle the carbon to the atmosphere within a few years, whereas carbon in stemwood has a turnover time counted in decades. In a steady-state ecosystem the net primary production is balanced by the total heterotrophic respiration plus other outputs. Non-respiratory outputs to be considered are fires and transport of organic material to the oceans. Fires mobilize about 5 Pg C/yr (Baes et ai, 1976 Crutzen and Andreae, 1990), most of which is converted to CO2. Since bacterial het-erotrophs are unable to oxidize elemental carbon, the production rate of pyroligneous graphite, a product of incomplete combustion (like forest fires), is an interesting quantity to assess. The inability of the biota to degrade elemental carbon puts carbon into a reservoir that is effectively isolated from the atmosphere and oceans. Seiler and Crutzen (1980) estimate the production rate of graphite to be 1 Pg C/yr. 

Most of the trichloroethylene used in the United States is released into the atmosphere by evaporation primarily from degreasing operations. Once in the atmosphere, the dominant trichloroethylene degradation process is reaction with hydroxyl radicals the estimated half-life for this process is approximately 7 days. This relatively short half-life indicates that trichloroethylene is not a persistent atmospheric compound. Most trichloroethylene deposited in surface waters or on soil surfaces volatilizes into the atmosphere, although its high mobility in soil may result in substantial percolation to subsurface regions before volatilization can occur. In these subsurface environments, trichloroethylene is only slowly degraded and may be relatively persistent. 

---