摘要:
A method is provided for reducing emissions of harmful nitrogen compounds from a pulp mill (e.g. kraft mill) having malodorous gases which include ammonia and reduced sulphur compounds therein. The method is practiced by (a) treating the pulp mill malodorous gases to lower the ammonia content thereof (e.g. by washing them with a bisulfite solution, such as one produced from washing flue gases with sodium sulphite), and then (b) burning the malodorous gases (e.g. in a dedicated incinerator, recovery boiler, power boiler, or lime kiln) under conditions which effect oxidation of reduced sulfur compounds therein (e.g. with an air excess of at least about 3% and a temperature of over 800 degrees C) so as to reduce odor emissions and emissions of harmful nitrogen compounds from the pulp mill. In the method (a) and (b) may be practiced using malodorous gas from a steam stripper as part of the malodorous gases treated, and the operating conditions, including the pH, of the stream stripper may be regulated in order to reduce the ammonia content of the clean condensate it produces.
摘要:
The present invention relates to a method for reducing nitrogen oxide emissions in combustion. Fuel is combusted in a first zone, whereby nitrogen oxides are generated. Supplementary fuel is fed in another zone under reducing conditions. At the same time, the temperature is adjusted so that nitrogen oxides convert essentially to hydrogen cyanide. Finally, air is fed in for finalizing the combustion and converting the hydrogen cyanide into nitrogen.
摘要:
A bioabsorbable implant or its part consists of a structure having a varying characteristic in at least in one direction defining a gradient corresponding this characteristic. The structure comprises bioabsorbable polymer and another substance within or next to said bioabsorbable polymer. The structure is constituted of a wound or folded blank (1) having a direction of variation (L) of a characteristic (Ch) which is at least one of the following: concentration of the other substance, species of the other substance, type of the bioabsorbable polymer, or porosity (size of openings in the blank), said structure having a winding axis or fold lines substantially perpendicular to said direction of variation (L). This results in said varying characteristic in the structure in said at least one direction defining the gradient and traversing superposed layers formed of sections of the blank (1) that are successive in said direction of variation (L).
摘要:
Porous bioabsorbable, bioactive and load-bearing composite medical device structure includes a plurality of regular textile planar layers (1a, 1b . . . ) formed of continuous bioabsorbable polymer matrix and bioceramic fibers acting as reinforcements, both included in continuous fibrous elements (3) forming the textile layers. The layers are placed on top of each other to form a structure having two dimensions (x, y) at right angles to each other according to the two dimensions of the textile layer and a third dimension (z) perpendicular to them and resulting from the piling of the layers. A plurality of passages extend through the layers as a result of the openings (2) defined by portions of the continuous fibrous elements (3) extending substantially in the direction of the plane. The continuous fibrous elements (3) comprise both bioactive ceramic reinforcing fibers which form a reinforcing structure and a bioabsorbable polymer matrix material which forms a matrix which binds the layers together and also binds the portions of continuous fibers defining the openings together, thereby forming the passages and stiffening the structure. This bioactive and bioabsorbable composite structure is suitable to be used as a basic structure in medical devices, especially in osteochondral applications where the load-bearing properties of implant are required.
摘要:
A bioactive glass composition which contains SiO2, Na2O, CaO, K2O, MgO, P2O5 and B2O3. The amount of SiO2 is 51-56 wt-% of the starting oxides, Na2O is 7-9 wt-% of the starting oxides, CaO is 21-23 wt-% of the starting oxides, K2O is 10-12 wt-% of the starting oxides, MgO is 1-4 wt-% of the starting oxides, P2O5 is 0.5-1.5 wt-% of the starting oxides, B2O3 is 0-1 wt-% of the starting oxides, provided that the total amount of Na2O and K2O is 17-20 wt-% of the starting oxides. Also disclosed is the manufacture and use of the bioactive glass composition.
摘要翻译:含有SiO 2,Na 2 O,CaO,K 2 O,MgO,P 2 O 2的生物活性玻璃组合物 5 O 3和B 2 O 3 3。 SiO 2的量为起始氧化物的51-56重量%,Na 2 O 2为起始氧化物的7-9重量%,CaO为21重量% 23重量%的起始氧化物,K 2 O 2为起始氧化物的10-12重量%,MgO为起始氧化物的1-4重量%,P < O 2 O 3为起始氧化物的0.5-1.5重量%,B 2 O 3 3为0-1重量%的0-1重量% 起始氧化物,条件是Na 2 O 2和K 2 O 2的总量为起始氧化物的17-20重量%。 还公开了生物活性玻璃组合物的制造和使用。
摘要:
A porous textile product made from bioactive glass fibers. The fibers in the product are of at least two types, fiber A and fiber B, with fiber A being made from a bioactive glass, and fiber B being made from a weakly bioactive glass.
摘要:
The amount of N.sub.2 O in flue gases discharged from a fluidized bed combustion system is minimized by adding an N.sub.2 O decomposing catalyst in a reactor stage downstream of the combustor. The catalyst preferably is a calcium based sorbent, such as CaO or or limestone, although NiO and other catalysts also may be utilized. Typically, the N.sub.2 O decomposition takes place without increasing the temperature of the flue gases above the 700.degree.-1000.degree. C. level that exists combustor. However, under some circumstances, if a second fluidized bed is provided as the reactor stage, additional fuel and oxygen can be added to increase the temperature of the flue gases to insure that it is over 800.degree. C. After N.sub.2 O decomposition, the flue gases may be passed through pressurized filter tubes, or through a superheater, economizer, air preheater, optional cyclone separator, and baghouse filter. A cyclone separator is preferably provided between the combustor and reactor stage, and the removed particles are recirculated to the combustor. Removal of particles, including unused sorbent, after the reactor stage also preferably takes place, with recycle to the reactor stage (if a fluidized bed stage) and/or to the combustor.
摘要:
Porous bioabsorbable, bioactive and load-bearing composite medical device structure includes a plurality of regular textile planar layers (1a, 1b . . . ) formed of continuous bioabsorbable polymer matrix and bioceramic fibers acting as reinforcements, both included in continuous fibrous elements (3) forming the textile layers. The layers are placed on top of each other to form a structure having two dimensions (x, y) at right angles to each other according to the two dimensions of the textile layer and a third dimension (z) perpendicular to them and resulting from the piling of the layers. A plurality of passages extend through the layers as a result of the openings (2) defined by portions of the continuous fibrous elements (3) extending substantially in the direction of the plane. The continuous fibrous elements (3) comprise both bioactive ceramic reinforcing fibers which form a reinforcing structure and a bioabsorbable polymer matrix material which forms a matrix which binds the layers together and also binds the portions of continuous fibers defining the openings together, thereby forming the passages and stiffening the structure. This bioactive and bioabsorbable composite structure is suitable to be used as a basic structure in medical devices, especially in osteochondral applications where the load-bearing properties of implant are required.
摘要:
The present invention relates to a bioabsorbable and bioactive composite material for surgical musculoskeletal applications comprising a bioabsorbable polymeric matrix material which is reinforced with bioabsorbable polymeric fibers and bioabsorbable ceramic fibers. The surgical bioabsorbable polymeric matrix material is reinforced with the bioabsorbable polymeric fibers and the bioabsorbable ceramic fibers from which at least a portion is longer than 150 μm. The invention also relates to a method for manufacturing a bioabsorbable and bioactive composite material.
摘要:
The present invention relates to a method for reducing nitrogen oxide emissions in combustion. Fuel is combusted in a first zone, whereby nitrogen oxides are generated. Supplementary fuel is fed in another zone under reducing conditions. At the same time, the temperature is adjusted so that nitrogen oxides convert essentially to hydrogen cyanide. Finally, air is fed in for finalizing the combustion and converting the hydrogen cyanide into nitrogen.