CONSIDERATION ON SOME HISTOMORPHOLOGICAL CHANGES IN EXPERIMENTAL ARTHRITIS IN RATS

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A STUDY OF SOME HISTOMORPHOLOGICAL CHANGES IN THE LYMPHORETICULAR APPARATUS OF ADULT RATS FOLLOWING THYMECTOMY

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Breaking Instance-Independent Symmetries In Exact Graph Coloring

Code optimization and high level synthesis can be posed as constraint satisfaction and optimization problems, such as graph coloring used in register allocation. Graph coloring is also used to model more traditional CSPs relevant to AI, such as planning, time-tabling and scheduling. Provably optimal solutions may be desirable for commercial and defense applications. Additionally, for applications such as register allocation and code optimization, naturally-occurring instances of graph coloring are often small and can be solved optimally. A recent wave of improvements in algorithms for Boolean satisfiability (SAT) and 0-1 Integer Linear Programming (ILP) suggests generic problem-reduction methods, rather than problem-specific heuristics, because (1) heuristics may be upset by new constraints, (2) heuristics tend to ignore structure, and (3) many relevant problems are provably inapproximable. Problem reductions often lead to highly symmetric SAT instances, and symmetries are known to slow down SAT solvers. In this work, we compare several avenues for symmetry breaking, in particular when certain kinds of symmetry are present in all generated instances. Our focus on reducing CSPs to SAT allows us to leverage recent dramatic improvement in SAT solvers and automatically benefit from future progress. We can use a variety of black-box SAT solvers without modifying their source code because our symmetry-breaking techniques are static, i.e., we detect symmetries and add symmetry breaking predicates (SBPs) during pre-processing. An important result of our work is that among the types of instance-independent SBPs we studied and their combinations, the simplest and least complete constructions are the most effective. Our experiments also clearly indicate that instance-independent symmetries should mostly be processed together with instance-specific symmetries rather than at the specification level, contrary to what has been suggested in the literature

Zel'dovich states with very small mass and charge in nonlinear electrodynamics coupled to gravity

It is shown that in non-linear electrodynamics (in particular, Born-Infeld one) in the framework of general relativity there exist "weakly singular" configurations such that (i) the proper mass M is finite in spite of divergences of the energy density, (ii) the electric charge q and Schwarzschild mass m ~ q can be made as small as one likes, (iv) all field and energy distributions are concentrated in the core region. This region has an almost zero surface area but a finite longitudinal size L=2M. Such configurations can be viewed as a new version of a classical analogue of an elementary particle.Comment: 11 pages. 1 reference added. To appear in Grav. Cosm

THE DEVICE OF THE ELECTRO-JIGSAW. EXPERIMENTAL STUDY OF THE CHARACTERISTICS OF THE ELECTRO-JIGSAW.

Lobzik (from German Laubsäge) is a tool for curvilinear sawing of materials. Manual mechanical Jigsaw includes an arched frame with a handle and clamps for mounting the saw blade. The saw blade is thin and narrow, thanks to which it is possible to change the direction of sawing. The frame has a large clearance between the canvas and its top, so it can bypass the edges of the workpiece. Manual jigsaw is usually used for processing of wood and its derivatives (in particular, plywood), and also in jeweller practice for processing nonferrous metals. Electric Jigsaw is a hand-held power tool for sawing of various materials with reciprocating movement of saw blade (Fig. 1). The manual electric Jigsaw includes a hull with a flat platform at the bottom and a handle at the top. Inside is an electric motor and a mechanism that transforms the rotational motion of the engine shaft into the reciprocating movement of the guide. For fastening of cloths the shank with a clamping screw or a spring clamp is used

Recurrent proofs of the irrationality of certain trigonometric values

We use recurrences of integrals to give new and elementary proofs of the irrationality of pi, tan(r) for all nonzero rational r, and cos(r) for all nonzero rational r^2. Immediate consequences to other values of the elementary transcendental functions are also discussed

An Open Inflationary Model for Dimensional Reduction and its Effects on the Observable Parameters of the Universe

Assuming that higher dimensions existed in the early stages of the universe where the evolution was inflationary, we construct an open, singularity-free, spatially homogeneous and isotropic cosmological model to study the effects of dimensional reduction that may have taken place during the early stages of the universe. We consider dimensional reduction to take place in a stepwise manner and interpret each step as a phase transition. By imposing suitable boundary conditions we trace their effects on the present day parameters of the universe.Comment: 5 pages, accepted for publication in Int. J. of Mod. Phys.

The behaviours of Mg and Ca in some types of ultramaphic alkaline melts in the presence of H 2 O at high temperature and pressure (the experimental data)

The sample has been investigated, which was composed of olivine-melilite rock from the south-western part of the Kugda intrusion, situated in the eastern margin of the Maimecha-Kotuiskay alkaline- ultramaphic province (northern part of Siberia platform). The experiments were carried out using a high-pressure apparatus of the "piston-cylinder" type. The pressure was 5-15 kb and the temperature -800-1250 0 C. The water content in the system was 3 and 9 wt. All experiments were carried out in hermetically sealed Pt or Au ampoules. The samples were chemically analyzed using a scanning electron microscope (SEM). Besides, the chemical composition of the experimental phases was determined by means of more than 40 electron microprobe in 20 experimental samples. For phase identification the X-ray method was used too. The structural peculiarities of rocks and mineral compositions were studied by optical methods in polished and thin sections prior and after the experiment. It was shown that at pressures above 7.5-8 kb the olivine-melilite melt is separated into two melts: pyroxenite and melilite. Most part of Mg in this system was concentrated in a high temperature phase of diopside type. The remaining melt was depleted of Mg and enriched by Ca. The mineralization vapour practically did not contain Mg. The main components of the mineralization vapour were Ca, Na, Si and Fe