The Effect of Nucleators on the Quality of the Surface of Glass-Ceramic Denture Coatings

The effect of nucleator additives on the surface relief and the degree of crystallization of material intended for the dentine and enamel layers of artificial denture is considered. It is established that hydroxyapatite additive is optimal for producing the required relief in the prime and dentine layers.     

Glauconite Materials from Belarus and Their Application Prospects

An integrated study of glauconite-bearing rocks of the Republic of Belarus has been performed and their main application directions have been identified. The chemical, mineral, and granulometric compositions of these rocks are studied and some of their physicochemical and technological properties are analyzed. __________ Translated from Steklo i Keramika, No. 6, pp. 7 – 9, June, 2005.     

Wettability of tundish periclase lining by steel

Results of a study of the wettability of the tundish periclase lining by molten steel using a sessile drop method are presented. The wetting angle θ tends to decrease with increase in temperature and contact time on adding glass fiber and Fe₂O₃ powder in excess of 2% to the magnesite powder; a similar effect is observed in steels high in manganese. An increase in angle θ is observed on adding carbon fiber or glass fiber (not in excess of 1%) to the magnesite powder; the angle θ tends to increase with increase in MgO powder grain size and with carbon contained in steel in excess of 0.04%. __________ Translated from Novye Ogneupory, No. 1, pp. 63–68, January, 2006.     

Minimal Energy Asynchronous Dynamic Adders

In battery-operated portable or implantable digital devices, where battery life needs to be maximized, it is necessary to minimize not only power consumption but also energy dissipation. Typical energy optimization measures include voltage reduction and operating at the slowest possible speed. We employ additional methods, including hybrid asynchronous dynamic design to enable operating over a wide range of battery voltage, aggregating large combinational logic blocks, and transistor sizing and reordering. We demonstrate the methods on simple adders, and discuss extension to other circuits. Three novel adders are proposed and analyzed: a 2-bit pass transistor logic (PTL) adder and two dynamic 2-bit adders. Circuit simulations on a 0.18-mum process at low voltage show that leakage energy is below 1%. The proposed adders achieve up to 40% energy savings relative to previously published results, while also operating faster     

Effect of reliability of grounding of the shaft of a turboset on the operation of devices for control and protection of exciting circuits

Disturbance of the grounding of the shaft of a turboset or its absence for technical reasons can result in failure, misoperation, limitation of the operating zone, errors or limitation of the sensitivity of devices for control and protection of exciting circuits from single-point leakage, and electroerosion of elements of the turboset structure. Measures for increasing the reliability of the grounding of the shaft are discussed. __________ Translated from élektricheskie Stantsii, No. 3, March 2006, pp. 61–66.     

Application of mortar elements to diffuse-interface methods

An adaptive 2D mesh refinement technique based on mortar spectral elements applied to diffuse-interface methods is presented. The refinement algorithm tracks the movement of the 2D diffuse-interface and subsequently refines the mesh locally at that interface, while coarsening the mesh in the rest of the computational domain, based on error estimators. Convergence of the method is validated using a Gaussian distribution problem and results are presented for a Cahn–Hilliard diffuse-interface model applied to capture the transient dynamics of polymer blends.     

Safety assessment of liquid radioactive wastes buried for a long time in deep repositories

The concepts of specific and absolute toxicity permit distinguishing in radioactive wastes belonging to different categories the particular components that present the greatest ecological danger at different stages of their disposal in repositories. It is shown that transuranium elements determine the toxicity parameter of high-and medium-level wastes only 350–400 years after initial disposal. At the present stage of operation of deep repositories, the behavior of the long-lived fission products of ⁹⁰Sr and ¹³⁷Cs is most important. For low-level wastes, the chemical and not the radioactive component is most dangerous. __________ Translated from Atomnaya énergiya,Vol. 100, No. 2, pp. 86–92, February, 2006.     

Gorillas (Gorilla gorilla) and Orangutans (Pongo pygmaeus) Encode Relevant Problem Features in a Tool-Using Task.

Two important elements in problem solving are the abilities to encode relevant task features and to combine multiple actions to achieve the goal. The authors investigated these 2 elements in a task in which gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus) had to use a tool to retrieve an out-of-reach reward. Subjects were able to select tools of an appropriate length to reach the reward even when the position of the reward and tools were not simultaneously visible. When presented with tools that were too short to retrieve the reward, subjects were more likely to refuse to use them than when tools were the appropriate length. Subjects were proficient at using tools in sequence to retrieve the reward. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anodising potential influence on well-ordered nanostructures formed by anodisation of aluminium in sulphuric acid

High-density structures with relatively well-ordered nanopore arrays have been obtained by the self-ordering growth of nanopores occurring during anodisation of aluminium in sulphuric acid. The resulting array of well-ordered nanopores strongly depends on an applied voltage of anodising, temperature and a procedure of synthesis. Regular arranged hexagonal arrays on aluminium with a relatively uniform pore diameter, interpore distance, and depth of pores exceeding 90 μm, can be formed by the self-ordering two-step anodising at 1 °C. The interpore distance and the pore diameter were evaluated on anodised aluminium layers obtained at different cell potentials ranging from 15 to 25 V. The detailed analyses of their uniformity were performed from SEM images. The analysis of a pore arrangement defects was made from SEM top view images taken on samples anodised at various cell potentials. The defect maps, known as Delaunay triangulations, of the arrangement of about 1000 pores were constructed for different applied anodising potentials. The percentage of pores that are not six-fold coordinated by the neighbouring pores indicates the percentage of defected surface.     

Simulating heat and mass transfer in regular distillation column packing

Plane-parallel packing of Mellapack 250X type (without perforations) is considered. Equation systems are given that describe the motion and heat and mass transfer in a layer of liquid and vapor. Calculations have been performed on nonstationary heat and mass transfer in cells of several types by the use of the STAR-CD software and the subroutines Star-Design and Pro-amm. Graphs are given for the velocity and vapor pressure distributions in cells of circular and triangular shape, as well as for the oxygen distribution in circular cells.