2,698 research outputs found
Interference effects during burning in air for stationary n-heptane, ethyl alcohol, and methyl alcohol droplets
Experiments have been conducted for the determination
of the evaporation constant and flame shapes of two and
of five closely spaced droplets burning in air. Droplets of
approximately the same and of different diameters were
used at various distances between the droplet centers.
The apparent flame shape, which was observed only for n-heptane droplets, changes very little during burning.
The square of the droplet diameter decreases linearly with
time for fixed spacing between droplet centers, at least
within the experimental limits of accuracy. In general,
the average evaporation constant for two droplets, K',
must be assumed either to vary continuously during burning
or else to be a function of average initial drop diameter,
D^0. The change of K' with time corresponds to the second
derivative in plots of the square of the diameter vs. time.
These second derivatives are not defined in our work because
of unavoidable scatter of the experimental data. Attempts at understanding the observed results by considering
published theories for single droplets, as well as groupings obtained from dimensional analysis, have been
unsuccessful. It appears that the diffusion model for
the heterogeneous burning of single fuel droplets will require serious revision and extension before the burning of
droplets arrays and sprays can be understood quantitatively.
Furthermore, the effective value of K' for a spray
probably depends not only on the fuel-oxidizer system but
also on the injection pattern. For this reason additional
studies had best be carried out under conditions corresponding to those existing in service models
Identification of Critical Elements That Deter TQM Program Success
This thesis reviews the Total Quality Management (TQM) program initially developed in Japan after World War II and its entry into the United States during the early Eighties.
TQM was incubated in Japan and matured into a viable program. TQM offered those who implemented the program improved quality products and improved cooperation between management and the workers for accomplishing common goals and objectives . The program focused on product quality and the belief that customer satisfaction is of key importance.
United States managers were searching for improved management programs to motivate workers, improve production and increase sales and profits . Global competitiveness was beginning to show on management\u27s bottom line and something had to happen quickly . When the TQM program became prominent in the United States management believed they had a management program that was simple and easy to implement . Armed with the belief that if the program is successful in Japan it would be successful in the United States.
Initial research on TQM programs in the United States indicated success was not as prevalent as in Japan . The question asked was why are enterprises in the United States encountering problems in the implementation of TQM? This thesis focused on identification of critical elements that deter TQM program success.
Research indicated t here were key elements that are essential to successful implementation of TQM. A TQM program will fail if the following elements are not properly used in the implementation process. The elements are management commitment, willingness to make cultural changes, empowering employees, permitting employees to participate in the decision making process, continuing extensive employee training and satisfying the customer
Liability of Telegraph Companies for Fraud, Accident, Delay and Mistakes in the Transmission and Delivery of Messages
Liability of Telegraph Companies for Fraud, Accident, Delay and Mistakes in the Transmission and Delivery of Messages (Continued)
A parametric model for heterogeneity in paired poisson counts
\Ve present a model for data in the form of match pairs of counts. Our work is motivated by a problem in fission track analysis, where the determination of a crystal age is based on the ratio of counts of spontaneous and induced tracks. It is often reasonable to assume that the counts follow a Poisson distribution but, typically, they are overdispersed and there exists a positive correlation between the numbers of spontaneous and induced tracks at the same crystal. We propose a model that allows for both overdispersion and correlation by assuming that the mean densities follow a bivariate Wishart distribution. Our model is quite general, having the usual negative binomial or Poisson models as special cases. \Ve propose a maximum likelihood estimation method based on a stochastic implementation of the EM algorithm and we derive the asymptotic standard errors of the parameter estimates. vVe illustrate the method by a data set of fission tracks counts in matched areas of zircon crystals
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