152,876 research outputs found

### Acyclic orientations on the Sierpinski gasket

We study the number of acyclic orientations on the generalized
two-dimensional Sierpinski gasket $SG_{2,b}(n)$ at stage $n$ with $b$ equal to
two and three, and determine the asymptotic behaviors. We also derive upper
bounds for the asymptotic growth constants for $SG_{2,b}$ and $d$-dimensional
Sierpinski gasket $SG_d$.Comment: 20 pages, 8 figures and 6 table

### Enhanced crystallinity of low temperature deposited silicon films on graphite subtrates

The previously developed technique of a sandwich coating for silicon crystallinity enhancement in silicon films deposited at low temperature is applied to graphite substrates. The measured increase in silicon crystallinity is comparable to that observed earlier using a quartz substrate. The distribution of aluminum in the silicon films is determined using Auger spectroscopic depth profiling. Carbon diffusion from the substrate into the silicon film is shown to be negligible at a substrate temperature of 600 C

### Structure of the Partition Function and Transfer Matrices for the Potts Model in a Magnetic Field on Lattice Strips

We determine the general structure of the partition function of the $q$-state
Potts model in an external magnetic field, $Z(G,q,v,w)$ for arbitrary $q$,
temperature variable $v$, and magnetic field variable $w$, on cyclic, M\"obius,
and free strip graphs $G$ of the square (sq), triangular (tri), and honeycomb
(hc) lattices with width $L_y$ and arbitrarily great length $L_x$. For the
cyclic case we prove that the partition function has the form $Z(\Lambda,L_y
\times L_x,q,v,w)=\sum_{d=0}^{L_y} \tilde c^{(d)} Tr[(T_{Z,\Lambda,L_y,d})^m]$,
where $\Lambda$ denotes the lattice type, $\tilde c^{(d)}$ are specified
polynomials of degree $d$ in $q$, $T_{Z,\Lambda,L_y,d}$ is the corresponding
transfer matrix, and $m=L_x$ ($L_x/2$) for $\Lambda=sq, tri (hc)$,
respectively. An analogous formula is given for M\"obius strips, while only
$T_{Z,\Lambda,L_y,d=0}$ appears for free strips. We exhibit a method for
calculating $T_{Z,\Lambda,L_y,d}$ for arbitrary $L_y$ and give illustrative
examples. Explicit results for arbitrary $L_y$ are presented for
$T_{Z,\Lambda,L_y,d}$ with $d=L_y$ and $d=L_y-1$. We find very simple formulas
for the determinant $det(T_{Z,\Lambda,L_y,d})$. We also give results for
self-dual cyclic strips of the square lattice.Comment: Reference added to a relevant paper by F. Y. W

### Two-directional active damper

Damper system to be used in studies of payload isolation technology is suitable as a laboratory apparatus. It provides easily adjustable damping and acts as multichannel shaker system

### Is there a resting frame in the universe? A proposed experimental test based on a precise measurement of particle mass

According to the Special Theory of Relativity, there should be no resting
frame in our universe. Such an assumption, however, could be in conflict with
the Standard Model of cosmology today, which regards the vacuum not as an empty
space. Thus, there is a strong need to experimentally test whether there is a
resting frame in our universe or not. We propose that this can be done by
precisely measuring the masses of two charged particles moving in opposite
directions. If all inertial frames are equivalent, there should be no
detectable mass difference between these two particles. If there is a resting
frame in the universe, one will observe a mass difference that is dependent on
the orientation of the laboratory frame. The detailed experimental setup is
discussed in this paper.Comment: 9 pages, 4 figure

### Dopant gas effect on silicon chemical vapor depositions: A surface potential model

A surface potential model is proposed to consistently explain the known dopant gas effects on silicon chemical vapor deposition. This model predicts that the effects of the same dopant gases on the diamond deposition rate using methane and carbon tetrachloride should be opposite and similar to those of silane, respectively. Available data are in agreement with this prediction

### A Fundamental and Feasibility Study of Ring- Vortex Gaseous-core Cavity Reactor Fifth Semiannual Report, 1 Feb. - 31 Jul. 1966

Feasibility study of ring-vortex gaseous-core cavity reacto

### The NLO QCD Corrections to $B_c$ Meson Production in $Z^0$ Decays

The decay width of $Z^0$ to $B_c$ meson is evaluated at the next-to-leading
order(NLO) accuracy in strong interaction. Numerical calculation shows that the
NLO correction to this process is remarkable. The quantum
chromodynamics(QCD)renormalization scale dependence of the results is obviously
depressed, and hence the uncertainties lying in the leading order calculation
are reduced.Comment: 14 pages, 7 figures; references added; expressions and typos ammende

### Mechanical behavior of thermal barrier coatings for gas turbine blades

Plasma-sprayed thermal barrier coatings (TBCs) will enable turbine components to operate at higher temperatures and lower cooling gas flow rates; thereby improving their efficiency. Future developments are limited by precise knowledge of the material properties and failure mechanisms of the coating system. Details of this nature are needed for realistic modeling of the coating system which will, in turn, promote advancements in coating technology. Complementary experiments and analytical modeling which were undertaken in order to define and measure the important failure processes for plasma-sprayed coatings are presented. The experimental portion includes two different tests which were developed to measure coating properties. These are termed tensile adhesion and acoustic emission tests. The analytical modeling section details a finite element method which was used to calculate the stress distribution in the coating system. Some preliminary results are presented

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