Abstract: A liquid level detection apparatus detecting a liquid level of a coolant stored in a coolant tank for an internal combustion engine, includes first and second electrodes immersed in the coolant and electrically connected to each other via the coolant when the liquid level of the coolant is higher than a predetermined position, a transmitter generating a sine wave including a specific frequency and equal amplitudes at positive and negative frequencies, the specific frequency being below a predetermined frequency, the transmitter sending the sine wave to one of the first and second electrodes, and a receiver including a band-pass filter receiving the sine wave outputted from the transmitter, via the other of the first and second electrodes to allow passage of the sine wave having the specific frequency, and a determination portion determining the liquid level of the coolant in accordance with the sine wave passed through the band-pass filter.

Abstract: Provided is a porous film which is excellent in a tear strength and has a low heat shrinkage. Such film is produced by subjecting to heat treatment on specific conditions, a porous film comprising a resin composition comprising: (a) a polypropylene base resin blend comprising 100 parts by weight of an ethylene-propylene block copolymer having a maximum peak temperature (Tm) of 140° C.≦Tm≦165° C. which is given by differential scanning calorimetry (DSC), 3 to 40 parts by weight of low density polyethylene and 3 to 40 parts by weight of an ethylene-vinyl acetate copolymer, (b) calcium carbonate, (c) titanium oxide coated on a surface thereof with silica and/or alumina, (d) a hindered amine light stabilizer having a molecular weight of 1500 to 4500, (e) an ethyl ester phosphorous acid or biphenylene phosphonite antioxidant, and (f) a hindered phenol antioxidant, wherein the above resin composition comprises 100 to 200 parts by weight of (b), 0.5 to 20 parts by weight of (c), 0.

Abstract: Provided is a porous film which is excellent in a tear strength and has a low heat shrinkage.

Abstract: Provided is a porous film which is excellent in a water vapor transmission rate, a tear strength and a weatherability. This porous film can be produced by melt-extruding, for example, by a T-die method, a composition comprising 100 parts by weight of a resin blend (1) comprising 100 parts by weight of {circle around (1)} an ethylene-propylene copolymer, 3 to 40 parts by weight of {circle around (2)} a low density polyethylene and 3 to 40 parts by weight of {circle around (3)} an ethylene-vinyl acetate copolymer and 100 to 200 parts by weight of calcium carbonate (2), or a composition comprising 100 parts by weight of the above resin blend (1), 100 to 200 parts by weight of calcium carbonate (2), 0.5 to 20 parts by weight of titanium dioxide (3) coated on a surface thereof with silica and/or alumina, 0.2 to 10 parts by weight of a hindered amine light stabilizer (4) having a molecular weight of 1500 to 4500 and 0.