Abstract:
A recessed seat retainer for a valve is secured in an annular recess on the face of a valve body by a totally internally disposed key system which does not create an external leak path. An annular keyway is formed in the cylindrical sidewall of a seat retainer. A key extends from the cylindrical sidewall of an annular recess formed in an axial face of the valve body. The key is received in the keyway and locks the retainer against axial dislodgement from the valve body.
Abstract:
A novel seat especially adapted for a butterfly valve is provided which is formed both of metal and "soft" material so as to furnish a "bubble tight" seal in normal operating conditions and a metal-to-metal seal in fire situations. The seat is uniquely constructed and is permanently deformed by the disc or closure member of the valve to form a precise size and configuration corresponding to the size and configuration of the disc.
Abstract:
A membrane for cultivating adherent or suspension cells, in particular adherent cells. The membrane permits adhesion and proliferation of the cells due to the irradiation of the wet or dry membrane with gamma or beta rays or an electron beam in a dose of from 12.5 to 175 kGy in the presence of oxygen. The resulting membrane may be used without any pre-treatment with surface-modifying substances. A method for preparing such an irradiated membrane for cultivating adherent or suspension cells. Methods of using such a membrane for cultivating adherent or suspension cells.
Abstract:
The present invention relates to high cut-off hemodialysis membranes for the treatment of chronic hemodialysis (CHD) patients, with the potential to improve long-term survival of these patients by reducing the risk of cardiovascular disease, through down-regulation of monocyte activation in the blood. Monocytes are the major circulating blood cells involved in the progression of cardiovascular disease. High cut-off hemodialysis in chronic dialysis patients results in a sustained decrease in expression of monocyte cell-surface proteins that direct the movement of these cells from the blood to the walls of blood vessels, where they promote the progression of arterial disease (atherosclerosis) that leads to cardiovascular disease (CVD); heart disease, strokes and peripheral vascular disease.
Abstract:
A process and a device for testing a hollow fiber membrane filter comprises two compartments separated by a porous membrane. A specific amount of testing liquid is provided via a line from a testing liquid reservoir.
Abstract:
A process for manufacturing of an asymmetric hollow fiber membrane, comprising the steps of extruding a polymer solution through the outer ring slit of a hollow fiber spinning nozzle, simultaneously extruding a center fluid through the inner bore of the hollow fiber spinning nozzle, into a precipitation bath, whereby the polymer solution contains 10 to 26 wt-% of polysulfone (PSU), polyethersulfone (PES) or polyarylethersulfone (PAES), 8 to 15 wt-% polyvinylpyrrolidone (PVP), 55 to 75 wt-% N-alkyl-2-pyrrolidone (NAP) and 3 to 9 wt-% water the centre fluid contains 70 to 90 wt-% N-alkyl-2-pyrrolidone (NAP) and 10 to 30 wt-% water, and the precipitation bath contains 0 to 20 wt-% N-alkyl-2-pyrrolidone (NAP) and 80 to 100 wt-% water.
Abstract:
A method for reconditioning a fuel cell stack. The method includes periodically increasing the relative humidity level of the cathode input airflow to the stack to saturate the cell membrane electrode assemblies to be greater than the relative humidity levels during normal stack operating conditions. The method also includes providing hydrogen to the anode side of the fuel cell stack at system shut down while the membrane electrode assemblies are saturated without stack loads being applied so that the hydrogen crosses the cell membranes to the cathode side and reacts with oxygen to reduce stack contaminants.
Abstract:
The invention relates to hydrophilic membranes which are supplemented or treated with a non-ionic surfactant and processes for preparing such membranes. The membranes are particularly suitable for plasma separation or for haemodialysis and haemodiafiltration, but can also advantageously be used in other applications. Accordingly, the invention is further directed to the use of such membranes for plasma separation, plasma filtration, micro filtration, plasma therapy, haemodialysis and haemodiafiltration or cell filtration applications, respectively. The treated hydrophilic membranes show excellent biocompatibility, such as reduced platelet drop and decreased TAT levels.
Abstract:
A process for manufacturing of an asymmetric hollow fibre membrane, comprising the steps of extruding a polymer solution through the outer ring slit of a hollow fibre spinning nozzle, simultaneously extruding a centre fluid through the inner bore of the hollow fibre spinning nozzle, into a precipitation bath, whereby the polymer solution contains 10 to 26 wt-% of polysulfone (PSU), polyethersulfone (PES) or polyarylethersulfone (PAES), 8 to 15 wt-% polyvinylpyrrolidone (PVP) and 60 to 80 wt-% N-alkyl-2-pyrrolidone (NAP), the centre fluid contains 60 to 70 wt-% N-alkyl-2-pyrrolidone (NAP) and 30 to 40 wt-% water, and the precipitation bath contains 70 to 82 wt-% N-alkyl-2-pyrrolidone (NAP) and 18 to 30 wt-% water.
Abstract:
A method for revising a reference polarization curve of a fuel cell stack that identifies the relationship between the voltage and the current of the stack over time. When the stack is operating at a low load where kinetic voltage losses of the stack dominate, a first adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve. When the stack is operating at higher loads where ohmic voltage losses of the stack dominate, a second adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve.