( Some valves use direct heating, in which a tungsten filament acts as both heater and cathode.

Some 19th-century or earlier experimental engines used external flames, exposed by valves, for ignition, but this becomes less attractive with increasing compression.

Some common operational problems are intrusion of air into the drive pipe, blockage of the intake or valves with debris, knocking due to having too little air in the pressure vessel, freezing in winter and bursting of the delivery pipe if output is blocked or pressure not relieved.

Some valves have no external control and do not need a stem as in most check valves.

Some valves are made to be operated in a gradual change between two or more positions.

Some valves are specially designed to regulate varying amounts of flow.

Some valves rated at very high pressures are available.

Some models benefit from variable camshaft timing, and multiple valves per cylinder.

Some of the specimens, such as the Tai Chi Man, demonstrate interventions, and include prosthetics such as artificial hip joints or heart valves.

Some operational problems were reported due to the high viscosity of vegetable oils compared to petroleum diesel fuel, which results in poor atomization of the fuel in the fuel spray and often leads to deposits and coking of the injectors, combustion chamber and valves.

Some bass-baritones were equipped with full-tone rotary valves to F in order for some of the hornline to be able to achieve the desired Bugle Low A, and in the mid-1960s a bass-baritone rotor to E was briefly offered.

Some patients with prosthetic heart valves however need antibiotic prophylaxis for dental surgery because bacteremia might lead to endocarditis ( infection causing inflammation of the interior lining of the heart ).

Some types of irrigation sprinklers and drip irrigation emitters have small check valves built into them to keep the lines from draining when the system is shut off.

Some of the early CVCC engines had a problem with the auxiliary valves retaining collars vibrating loose.

Some airless pumps have a diaphragm instead of a piston, but both types have inlet and outlet valves.

Some GCs also include valves which can change the route of sample and carrier flow.

Some ball valves are equipped with an actuator that may be pneumatically or motor operated.

Some governments require the use of two chemigation valves installed in series if hazardous chemicals are to be injected.

Some of the less directly visible differences were poorly shaped ports in the earlier versions, a slow burning combustion chamber with heavily shrouded valves, less aggressive camshaft profiles, ports of a small cross sectional area, a very restrictive intake manifold with long runners joined to a small displacement plenum and other changes.

Some blowoff valves are sold with a trumpet-shaped exit that intentionally amplifies the sound.

Some SOHC multi-valve engines ( such as the Mazda B8-ME ) use a single fork-shaped rocker arm to drive two valves ( generally the exhaust valves ) so that fewer cam lobes will be needed in order to reduce manufacturing costs.

Some painters have less interest in the experience of the moment, with its attendant urgencies and ambiguities, than in looking beyond the flux of particular impressions to a higher, more serene level of truth.

Some of the earlier episodes have touches of the supernatural, as suited to the legendary background.

Some historians have found his point of view not to their taste, others have complained that he makes the Tory tradition appear `` contemptible rather than intelligible '', while a sympathetic critic has remarked that the `` intricate interplay of social dynamics and political activity of which, at times, politicians are the ignorant marionettes is not a field for the exercise of his talents ''.

Some of these thoughts -- not all of them -- have taken organized form in later years.

He said, `` Some have criticized your book as being neither literary criticism nor history.

Some have felt that Washington Irving comes out rather slimly, but let them look at the title of the book ''.

Some of us have imagination and sensibility too.

Some of former President Truman's off-the-cuff discourses have been in that vein.

Some of the stumps are as much as three feet long, but most of them have been flattened by the pressure of the overlying sediments.

Some memorable plays have been drawn from books, notably Life With Father and Diary Of Anne Frank.

Some families already have held weekend rehearsals in their home shelters to learn the problems and to determine for themselves what supplies they would need.

Some special health requirements might have to be met.

Some weapons systems have become obsolescent while still in production, and some while still under development.

Some offices have very broad responsibilities, touching on almost all aspects of a university's instructional program.

Some manufacturers have had the foresight to provide a socket for the chuck key ; ;

Some recreation features, such as scenic values and water interest, also have greater overall value than other interests.

-- Some areas may already have been improved and contain buildings, roads, utilities, cleared land, etcetera which may raise the cost of the site.

Some distribution costs are kept up by competitive pressure, some by the fact that the customers have come to expect certain niceties and flourishes.

Some men have no talent for or interest in management ; ;

Some agents have been shown to be much more toxic or infectious to experimental animals when exposed to aerosols of optimum particle size than by the natural portal.

Some of those who question the value of BW have assumed that the only potential would be in the establishment of epidemics.

Some members of the bee family have become idlers, social parasites that live at the expense of their hardworking relatives.

Some investigators have found a parallelism between remissions and return of the sympathetic reactivity of the hypothalamus to the normal level as indicated by the Mecholyl test and, conversely, between clinical impairment and increasing deviation of this test from the norm.

Some of the oldest, most persistent, and most cohesive forms of social groupings have grown out of religion.