Abstract: A method for controlling a cooling system for an internal combustion engine having first and second cooling fans is provided, comprising operating the first cooling fan at a first rotational frequency which is greater than a combustion frequency of the internal combustion engine and operating the second cooling fan at a second rotational frequency which is less than the combustive vibration frequency of the internal combustion engine. Since the rotational frequencies of the first and second cooling fans are different from the combustion frequency of the internal combustion engine, the resonance between the rotational vibration of the cooling fans and the combustive vibration of the internal combustion engine may be prevented. Also, since the rotational frequencies of the first and second cooling fans are different from each other so that the resonance between their rotational vibrations may be prevented.

Abstract: A method for controlling a cooling system for an internal combustion engine having first and second cooling fans is provided, comprising operating the first cooling fan at a first rotational frequency which is greater than a combustion frequency of the internal combustion engine and operating the second cooling fan at a second rotational frequency which is less than the combustive vibration frequency of the internal combustion engine. Since the rotational frequencies of the first and second cooling fans are different from the combustion frequency of the internal combustion engine, the resonance between the rotational vibration of the cooling fans and the combustive vibration of the internal combustion engine may be prevented. Also, since the rotational frequencies of the first and second cooling fans are different from each other so that the resonance between their rotational vibrations may be prevented.

Abstract: To provide a photosensitive resin composition and a photosensitive element using the resin composition with excellent sensitivity and adhesion as well as high resolution and plating resistance. A photosensitive resin composition, comprises (A) a polymer carrying carboxyl groups, (B) a compound carrying at least one ethylene-based unsaturated group in the molecule, and (C) a photopolymerization initiator, characterized by the fact that component (B) contains at least 60 weight % of methacrylate (B1) carrying at least one ethylene-based unsaturated group with respect to the total amount of component (B), that the amount of component (C) is in the range of 0.01-20 weight units with respect to 100 weight units of component (A) and component (B), and that component (C) contains 2-5 weight units of lophine dimer (C1) and 0.1-2.0 weight units of triphenylphosphine (C2) with respect to 100 weight units of component (A) and component (B), as well as a photosensitive element using the resin composition.

Abstract: A negative acting photoimageable composition comprisesA) between about 30 and about 70 wt %, based on total weight of A) plus B), of a organic binder polymers having sufficient acid functionality to render said photoimageable composition developable in alkaline aqueous solution,A) comprising between about 3 and about 65 wt % relative to total of A) plus B) a binder polymer A') having a weight average molecular weight between about 5000 and about 40,000 and a T.sub.g of between about 40 and about 100, and 5 to 67 wt % relative to total of A) plus B) a binder polymer A") having a weight average molecular weight between about 41,000 and about 200,000 and a T.sub.g of between about 40 and about 100,B) between about 30 and about 60 wt %, based on total weight of A) plus B), of .alpha.,.beta.-ethylenically unsaturated compounds, said component B) comprisingB') an isocyanate trimer having tri-.alpha.,.beta.

Abstract: The invention provides a negative-acting photoimageable composition comprising A) between about 30 and about 80 wt % based on total weight of A) plus B) of a binder polymer having acid functionality sufficient to render said photoimageable composition developable in alkaline aqueous solution, B) between about 20 and about 70 wt % based on total weight of A) plus B) of an addition-polymerizeable, non-gaseous .alpha.,.beta.-ethylenically unsaturated compound(s) capable of forming a high polymer by free-radical initiated chain-propagating addition polymerization, at least about 50 mole percent of the .alpha.,.beta.-ethylenically unsaturated moieties of B) being methacrylic moieties, and C) between about 0.1 and about 20 wt % based on total weight of A) plus B) of a photoinitiator chemical system, the photoinitiator chemical system comprising between about 0.005 and about 3 wt % relative to total weight of A) plus B) of triphenyphosphine and between about 0.