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 control rod for a nuclear reactor according to the present invention is such that neutron absorbing rods are surrounded with a second neutron absorber which differs in material from the neutron absorbing rods. In a case where the neutron absorbing rod is composed of boron carbide powder and a cladding for receiving the powder therein, the second neutron absorber is a sheet of a material having a neutron irradiation lifetime longer than that of boron carbide, for example, hafnium. In a case where the neutron absorbing rod is a round hafnium rod, the second neutron absorber having a neutron absorption worth higher than that of hafnium is located so as to surround the round hafnium rods. Thus, the neutron absorbing rods are effectively used, and the lifetime of the control rod can be prolonged in the former.
Abstract:
Feed additives for ruminants comprises tablets or granules of a mixture of biologically active ingredient(s), chitosan and protective material(s) which are one or more substance(s) selected from the group consisting of saturated or unsaturated aliphatic mono-carboxylic acids having 14 to 22 carbon atoms, hardened vegetable oils and hardened animal oils.By containing chitosan, said feed additives easily pass through the rumen and are easily digested by digestive organs from abomasum, consequently said biologically active ingredient(s) are efficiently absorbed by oral feeding to ruminants.
Abstract:
An alkaline storage battery such as a sealed nickel-cadmium storage battery has an improved current collector tab structure connected as a current path to the marginal edge of a spirally coiled electrode of an electrode assembly. The current collector tab structure comprises either a plurality of current collector tabs or a single current collector tab comprising a current collecting tab and a lead tab thicker than the current collecting tab. With this arrangement, the internal resistance of the storage battery is reduced, and high-rate discharge performance is achieved.
Abstract:
In a light water moderation type nuclear reactor with the once-through method, the reactor core is divided into a central area and a peripheral area by a partition member, a first fuel assembly is arranged in the central area (high conversion area) and a second fuel assembly is arranged in the peripheral area. The ratio (r.sub.H/U) of the number of hydrogen atoms to that of uranium atoms in the central area is smaller than that of the ratio in the peripheral area and the second fuel assembly in the peripheral area is formed of fuel rods of the first fuel assembly having been previously burned in the central area and moved into the peripheral area. The plutonium production increases and uranium consumption is reduced during the first half of the lifetime of the fuel rods in the high conversion area with the take-up burn up increasing during the second half of the lifetime of the fuel rods in the burner area.
Abstract:
Reference logical data is spatially divided by a data dividing circuit for each time slot, and the divided data are converted into data, each having a continuous effective period. The divided and converted reference data and input logical data are compared by comparators to detect whether or not they are coincident with each other. A clock signal for determining the timing of comparison is also divided by a clock signal dividing circuit into n clock signals which are displaced one time slot apart in phase and occurring with a period of n time slots. By these divided clock signals those of the outputs from the comparators corresponding thereto are taken out from a comparison output circuit.
Abstract:
An alkaline storage battery such as a sealed nickel-cadmium storage battery has an improved upper current collector tab welded to the terminal edge of a spirally wound electrode of a spirally coiled electrode assembly. The current collector tab comprises a current collecting tab and a lead tab. The current collecting tab is higher in electric resistance than the lead tab, so that the current collecting tab can easily be welded to the terminal edge of the electrode of the electrode assembly. The lead tab provides a low internal resistance to allow charging and discharging electric currents to flow easily for improved high-rate discharge performance of the battery.
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:
A pentadecapeptide and salts thereof with immunopotentiating activity is presented. Also presented is a fermentation process for the preparation of the pentadecapeptide by a microorganism of the genus Streptoverticillium and pharmaceutical preparations containing the peptide or its salts.