Hot-pressing process modeling for medium density fiberboard (MDF)

In this paper we present a numerical solution for the mathematical modeling of the hot-pressing process applied to medium density fiberboard. The model is based in the work of Humphrey[82], Humphrey and Bolton[89] and Carvalho and Costa[98], with some modifications and extensions in order to take into account mainly the convective effects on the phase change term and also a conservative numerical treatment of the resulting system of partial differential equations.Comment: LaTeX, 11 figures. Added references. Fixed some errors. To appear in International Journal of Mathematics and Mathematical Sciences, http://jam.hindawi.co

Coronal heating in coupled photosphere-chromosphere-coronal systems: turbulence and leakage

Coronal loops act as resonant cavities for low frequency fluctuations that are transmitted from the deeper layers of the solar atmosphere and are amplified in the corona, triggering nonlinear interactions. However trapping is not perfect, some energy leaks down to the chromosphere, thus limiting the turbulence development and the associated heating. We consider the combined effects of turbulence and leakage in determining the energy level and associated heating rate in models of coronal loops which include the chromosphere and transition region. We use a piece-wise constant model for the Alfven speed and a Reduced MHD - Shell model to describe the interplay between turbulent dynamics in the direction perpendicular to the mean field and propagation along the field. Turbulence is sustained by incoming fluctuations which are equivalent, in the line-tied case, to forcing by the photospheric shear flows. While varying the turbulence strength, we compare systematically the average coronal energy level (E) and dissipation rate (D) in three models with increasing complexity: the classical closed model, the semi-open corona model, and the corona-chromosphere (or 3-layer) model, the latter two models allowing energy leakage. We find that: (i) Leakage always plays a role (even for strong turbulence), E and D are systematically lower than in the line-tied model. (ii) E is close to the resonant prediction, i.e., assuming effective turbulent correlation time longer than the Alfven coronal crossing time (Ta). (iii) D is close to the value given by the ratio of photospheric energy divided by Ta (iv) The coronal spectra exibits an inertial range with 5/3 spectral slope, and a large scale peak of trapped resonant modes that inhibit nonlinear couplings. (v) In the realistic 3-layer model, the two-component spectrum leads to a damping time equal to the Kolmogorov time reduced by a factor u_rms/Va_coronaComment: 15 pages, 15 figures, Accepted for publication in A&

Integrals of Motion for Critical Dense Polymers and Symplectic Fermions

We consider critical dense polymers ${\cal L}(1,2)$. We obtain for this model the eigenvalues of the local integrals of motion of the underlying Conformal Field Theory by means of Thermodynamic Bethe Ansatz. We give a detailed description of the relation between this model and Symplectic Fermions including the indecomposable structure of the transfer matrix. Integrals of motion are defined directly on the lattice in terms of the Temperley Lieb Algebra and their eigenvalues are obtained and expressed as an infinite sum of the eigenvalues of the continuum integrals of motion. An elegant decomposition of the transfer matrix in terms of a finite number of lattice integrals of motion is obtained thus providing a reason for their introduction.Comment: 53 pages, version accepted for publishing on JSTA

How to Train yourself to be Healthier by Best Breathing!

Breathing is so natural that the "best way to breathe" has never been identified or promoted as such.  Having episodes of  life-threatening laryngospasm prompted research and study on breathing, resulting in the discovery that nasal inhaling is "best" by shutting one's mouth and concentrating on getting more oxygenation.  "SAM More Oxygen" describes the "best way to breathe:   SHUT your mouth.  AIR in thru nose.  MOUTH exhale or stay shut or cough harshly to clear throat and lungs" (but when doing a series of SAMs, cough harshly every third and fourth time to help clean your lungs and larynx)."  The discovery occurred while in laryngospasm.  Intensely aware of the miserable duration of previous barely effective horrible mouth clearing trying-to-breathe efforts, a conscious decision of "I am not going to go thru this again because it is torture", the mouth was shut against all natural impulses to use mouth breathing to clear my choking laryngospasm; and, amazingly, air inhalation thru the nose occurred enabling a strong cough which opened the airway; repeating the sequence many times enabled calmer more efficient return to normal breathing. The process was quickly called "SAM" and it worked every time ever since. It went into medical publication and many grateful letters were received from people who found it giving relief never before as fast or effective. Since then, research and study of breathing clearly shows the SAM More Oxygen will help many medical problems and maintain good health.   But you need to practice it over and over to remember to do it.  Regular breathing automatically returns but it is not "best breathing." When relaxing watching T.V. or on your computer, best breathe by gentle SAMs.  Do a few when you wake up every morning--get a little more oxygen to help wake up and energize for the day.  Remind each other too to SAMMO

The Role of Cognitive Distractibility in Special Education Diagnosis

The three factor scores that Kaufman (1975) measured on the Weschler Intelligence Scale for Children-Revised (Freedom from Distractibility, Perceptual Organization, and Verbal Comprehension) were compared among students referred and/or placed in special education. Three diagnostic groups were compared: behavioral disordered (BD) , learning disabled (LD) and students who were referred but not placed in special education. Results indicated a significant factor structure difference on the WISC-R for the BD and LD diagnostic groups, but not for the referred but not placed students. However, only the LD group manifested a significantly lower distractibility factor score when compared to the referred but not placed group. Hence, they appear to be more distractible than the BD group— a finding opposite of that expected. An imbalance among the factors measured on the WISC-R appears to be a significant factor to consider in the diagnosis of a handicapping condition

Support and power plant documentation for the gas turbine powered bus demonstration program

The operational experience obtained for the GT404-4 gas turbine engines in the intercity and intracity Bus Demonstration Programs is described for the period January 1980 through September 1981. Support for the engines and automatic transmissions involved in this program provided engineering and field service, spare parts and tools, training, and factory overhauls. the Greyhound (intercity) coaches accumulated 183,054 mi (294,595 km) and 5154 hr of total operation. The Baltimore Transit (intracity) coaches accumulated 40,567 mi (65,285 km) and 1840 hr of total operation. In service, the turbine powered Greyhound and Transit coaches achieved approximately 25% and 40% lower fuel mileage, respectively, than did the production diesel powered coaches. The gas turbine engine will require the advanced ceramic development currently being sponsored by the DOE and NASA to achieve fuel economy equivalent not only to that of today's diesel engines but also to the projected fuel economy of the advanced diesel engines of the 1990s. Sufficient experience was not achieved with the coaches prior to the start of service to identify and eliminate many of the problems associated with the startup of new equipment. Because of these problems, the mean miles between incident were unacceptably low. The future gas turbine system should be developed sufficiently to establish satisfactory durability prior to evaluation in revenue service. Commercialization of the gas turbine bus engine remains a viable goal for the future