Abstract: A tracking connection system includes a portable telephone set and a plurality of switching units. The portable telephone set receives a calling signal containing a called number and sends a response signal. Each switching unit has a unique management area, in which communication is performed with the portable telephone set, and transmits a calling signal to the portable telephone set present in the management area. Each switching unit includes a memory, a detecting section, and a tracking destination deciding section. The memory serves to store tracking sequence data indicating a sequence for tracking the portable telephone set in advance. The detecting section detects whether the portable telephone set as a calling target is present in the corresponding management area.

Abstract: In an initial core constituted by various kinds of fuel assemblies having a different average enrichment of uranium 235 four fuel assemblies having the lowest average enrichment constitute a square shaped cell. Three fuel assemblies having the highest average enrichment constitute an L-shaped cell, and the L-shaped cell is arranged at corners of the square shaped cells, whereby each assembly of the L-shaped cell adjoins a square shaped cell. The ratio of the number of assemblies of the L-shaped cell to the total number of fuel assemblies in the core is 10% or more.

Abstract: The reactor shut-down margin and the thermal margin, as well as the output per unit volume of the core is increased. When A is the total cross sectional area of the non-boiling water areas in the channel boxes each surrounding a fuel assembly and non-boiling water areas outside the channel boxes and B is the cross sectional areas of boiling water areas in the channel boxes, the relation of 1>B/(A+B).gtoreq.0.76 is set. A control unit adjusts a rotational speed of a recirculation internal pump which controls the cooling water flow rate per unit area in the core section to 3.0.times.10.sup.3 t/h/m.sup.2 at the beginning of the operation cycle and controls the cooling water flow rate per the unit area in the core cross section to 3.3.times.10.sup.3 t/h/m.sup.2 at the end of an operation cycle.

Abstract: A fuel assembly and a reactor core using same which are able to increase size of the fuel assembly with ensuring thermal margin and reactor shut down margin.A distance between centers of adjacent fuel assemblies is about 23 cm, which is enlarged about 1.5 times of conventional fuel assemblies. A thickness of water gap region is about 16 cm, which is relatively thinner than that of prior art. While, H/U ratio is about 5 as same as that of the prior art, and decreasing amount of non-boiling water in the water gap region is arranged in a channel box as water rods. Consequently, a ratio of transversal cross section area of the water rods to transversal cross section area of the fuel rods becomes about 0.6, and local power peaking factor can be decreased and thermal margin can be increased. Further, the transversal cross section area of the water rod is selected to be 15 cm.sup.2 so as to ensure the reactor shut down margin by reducing excess reactivity.

Abstract: A nuclear fuel assembly has an array of fuel rods comprising a plurality of first fuel rods each containing nuclear fuel material but not containing burnable poison and a plurality of further fuel rods each containing both nuclear fuel material and burnable poison. The further fuel rods comprise second fuel rods and third fuel rods, and each second fuel rod has at a lower region of the fuel assembly a burnable poison concentration which is a minimum burnable poison concentration in the further fuel rods. To increase the effectiveness of the second fuel rods in controlling axial power peaking, as seen in plan view on the array, the first fuel rods are the nearest neighbors of each further fuel rod.

Abstract: A nuclear fuel assembly for a nuclear reactor has a plurality of vertically extending fuel rods arranged side by side in a square array and containing fissile material. The array has two adjacent first sides which are next to a control rod region of the core and two adjacent second sides which are next to a non-control rod region of the core.

Abstract: A core of boiling water reactor is divided into a central region and a peripheral region surrounding it in the radial direction thereof. The loading fraction of new first fuel assemblies containing burnable poison and loaded in the central region is greater than the loading fraction of the new first fuel assemblies loaded in the peripheral region. The loading fraction of second fuel assemblies loaded in the central region of the core and operating in a second operation cycle is smaller than the loading fraction of the second fuel assemblies loaded in the peripheral region of the core and operating in the second operation cycle. The second fuel assemblies contain no burnable poison. In such a core, the reactivity of the peripheral region is greater than that of the central region in the beginning of an operation cycle. Contrary, the reactivity of the central region is greater than that of the peripheral region in the end of an operation cycle.

Abstract: A fuel assembly has a plurality of first fuel rods each of which contains nuclear fuel material but does not contain burnable poison, and a plurality of second fuel rods each of which includes nuclear fuel material and burnable poison. The amount of burnable poison in a lower region of the fuel assembly is smaller than that in an upper region thereof. When each of the second fuel rods is divided into an upper region and a lower region, a region of the divided regions in the second fuel rods containing a maximum burnable poison concentration Gmax and a region of the divided regions in the second fuel rods containing a minimum burnable poison concentration Gmin are located in the lower region of the fuel assembly. The burnable poison concentration of the upper region of each second fuel rod is between Gmax and Gmin. The fuel assembly may moderate a maximum linear heat rating with an increased spectral shift effect.

Abstract: The reactor core is divided into a central region and a surrounding outer region in the radial direction. First fresh fuel unirradiated assemblies newly loaded onto the outer region contain a fissible material in amounts less than that of the fissible material of second fresh unirradiated fuel assemblies newly loaded onto the central region. If the amount of the fissible material in the upper region of the first fuel assembly is denoted by a, the amount of the fissible material in the lower region of the first fuel assembly by b, the amount of the fissible material in the upper region of the second fuel assembly by c, and the amount of the fissible material in the lower region of the second fuel assembly by d, then a relationship a/b<c/d is satisfied. The reactor core provides sufficient thermal margin and improved cold shutdown margin.

Abstract: A modified powder or particulate material having a silicone polymer film coated on substantially the entire surface thereof, this powder or particulate material being produced by bringing at least one silicone compound, in the form of a vapor, having the general formula (I):(R.sup.1 HSiO).sub.a (R.sup.2 R.sup.3 SiO).sub.b (R.sup.4 R.sup.5 R.sup.6 SiO.sub.1/2).sub.c (I)Wherein R.sup.1, R.sup.2, and R.sup.3 represent, independently, hydrogen or a hydrocarbon residue having 1 to 10 carbon atoms, which may be substituted with at least one halogen atom, provided that R.sup.1, R.sup.2, and R.sup.3 are not hydrogen at the same time, R.sup.4, R.sup.5, and R.sup.

Abstract: A modified powder or particulate material coated on substantially the entire surface thereof with a film of a silicone polymer carrying a pendant group thereon, this powder or particulate material being produced by a process comprising the steps of(a) coating the powder or particulate material with a film of a silicone polymer having at least one Si-H moiety, and(b) carrying out an addition reaction of a compound capable of reacting with an Si--H moiety to the Si--H moiety in the silicone polymer of step (a), whereby the pendant group derived from said compound is bonded to the silicone polymer.

Abstract: A modified powder or particulate material having a silicone polymer film coated on substantially the entire surface thereof, this powder or particulate material being produced by bringing at least one silicone compound, in the form of a vapor, having the general formula (I):(R.sup.1 HSiO).sub.a (R.sup.2 R.sup.3 SiO).sub.b (R.sup.4 R.sup.5 R.sup.6 SiO.sub.1/2).sub.c (I)wherein R.sup.1, R.sup.2, and R.sup.3 represent, independently, hydrogen or a hydrocarbon residue having 1 to 10 carbon atoms, which may be substituted with at least one halogen atom, provided that R.sup.1, R.sup.2, and R.sup.3 are not hydrogen at the same time, R.sup.4, R.sup.5, and R.sup.

Abstract: A packing material for liquid chromatography, comprising particles having a silicone polymer film coated on substantially the entire surface thereof, the packing material being produced by a process comprising the steps of:(a) bringing at least one silicone compound having the general formula (I):(R.sup.1 HSiO).sub.a (R.sup.2 R.sup.3 SiO).sub.b (R.sup.4 R.sup.5 R.sup.6 SiO.sub.1/2).sub.c (I)wherein R.sup.1, R.sup.2, and R.sup.3 represent, independently, a hydrocarbon residue having 1 to 10 carbon atoms, which may be substituted with at least one halogen atom, R.sup.4, R.sup.5, and R.sup.