33,126 research outputs found
The economic value of remote sensing of earth resources from space: An ERTS overview and the value of continuity of service. Volume 4: Forestry, wildlife and rangeland
The economic value of ERS information in the resource management area of extensive use of living resources, forestry, wildlife, and rangeland, is determined. Timber and forage resources are quantitatively evaluated. It is shown that these resources have economic value in the tens of billions of dollars, but the economic benefits of improved management of the forests and rangelands are not limited to efficiency in the production of these commercial resources. Multiple-use values including watershed, wildlife, and recreation are also involved
Inverter ratio failure detector
A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship
Effects of an on line bypass oil recycler on emissions with oil age for a bus using in service testing
A method of cleaning lubricating oil on line was
investigated using a fine bypass particulate filter
followed by an infra red heater. Two bypass filter
sizes of 6 and 1 micron were investigated, both filter
sizes were effective but the one micron filter had the
greatest benefit. This was tested on two nominally
identical EURO 2 emissions compliance single
decker buses, fitted with Cummins 6 cylinder 8.3 litre
turbocharged intercooled engines and coded as Bus
4063 and 4070. These vehicles had emissions
characteristics that were significantly different, in
spite of their similar age and total mileage. Bus 4063
showed an apparent deterioration on emissions with
time while Bus 4070 showed a stabilised trend on
emissions with time for their baseline tests without
the recycler fitted. Comparison was made with the
emissions on the same vehicles and engines with
and without the on-line bypass oil recycler. Engine
exhaust emissions were measured about every 2000
miles. All tests started with an oil drain and fresh
lubricating oil. The two buses were tested in a
different sequence, Bus 4063 with the recycler fitted
and then removed later in the test after an oil change
and Bus 4070 with no recycler fitted at first and then
fitted after 29,000 miles with no oil change. The Bus
4070 was also the one with the finer bypass filter.
The test mileage was 45,000 miles for Bus 4063 and
48,000 miles for Bus 4070. The air/fuel ratio was
worked out by the exhaust gas analysis. The
correlation between air/fuel ratio and emission
parameters was determined. The results showed that
the on line oil recycler cleaning system reduced the
rate of increase of the NOx from 5% to 1.6% for Bus
4063 and from 4.1% to 0% for Bus 4070 per 10,000
miles. Hydrocarbon emissions increased 30 ppm per
10,000 miles with the recycler removed compared to
a stabilised level with the recycler fitted for Bus 4063.
There was a small decrease in hydrocarbon
emissions after fitting the recycler for Bus 4070. The
particulate emissions were reduced by 35% for Bus
4063 and 24% for Bus 4070 on average. The
reductions on total particulate mass were due to
reductions on particulate carbon and lube oil VOF
emissions. The black smoke was reduced by 56% for
Bus 4063 in terms of rate of increase and 40% for
Bus 4070 in terms of average value
The influence of an oil recycler on emissions with oil age for a refuse truck using in service testing
A method of cleaning lubricating oil on line was
investigated using a fine bypass particulate filter followed
by an infra red heater. Two bypass filter sizes of 6 and 1
micron were investigated, both filter sizes were effective
but the one micron filter had the greatest benefit. This
was tested on two nominally identical EURO 1 emissions
compliance refuse trucks, fitted with Perkins Phazer
210Ti 6 litre turbocharged intercooled engines and coded
as RT320 and RT321. These vehicles had emissions
characteristics that were significantly different, in spite of
their similar age and total mileage. RT321 showed an
apparent heavier black smoke than RT320. Comparison
was made with the emissions on the same vehicles and
engines with and without the on-line bypass oil recycler.
Engine exhaust emissions were measured about every
400 miles. Both vehicles started the test with an oil drain
and fresh lubricating oil. The two refuse trucks were
tested in a different sequence, the RT320 without the
recycler fitted and then fitted later and the RT321 with
the recycler fitted and then removed later in the test and
both without any oil change. The RT320 was also the
one with the finer bypass filter. The test mileage was
nearly 8,000 miles both trucks. The air/fuel ratio was
worked out by the exhaust gas analysis. The correlation
between air/fuel ratio and emission parameters was
determined and appropriate corrections were made in
the case of that the air/fuel ratio had an effect on
emissions. The results showed that the on line oil
recycler cleaning system can reduce the rate of increase
of the NOx with oil age. There appeared little influence of
the oil recycler on carbon monoxide and hydrocarbon
emissions. The rate of increase in particulate emissions
was reduced by 50% for RT320 and an immediate
decrease in particulate emissions was seen on RT320
test after fitting the recycler. The black smoke was
reduced by 30% for RT320 in terms average value and
an immediate decrease in smoke after fitting the recycler
on RT320 test and an immediate increase in smoke after
the removal of the recycler on RT321 test were shown
Fermionic characters for graded parafermions
Fermionic-type character formulae are presented for charged
irreduciblemodules of the graded parafermionic conformal field theory
associated to the coset . This is obtained by counting the
weakly ordered `partitions' subject to the graded exclusion principle.
The bosonic form of the characters is also presented.Comment: 24 p. This corrects typos (present even in the published version) in
eqs (4.4), (5.23), (5.24) and (C.4
The Dust Properties of Eight Debris Disk Candidates as Determined by Submillimeter Photometry
The nature of far-infrared dust emission toward main sequence stars, whether
interstellar or circumstellar, can be deduced from submillimeter photometry. We
present JCMT/SCUBA flux measurements at 850 microns toward 8 stars with large
photospheric excesses at 60-100 microns. 5 sources were detected at 3-sigma or
greater significance and one was marginally detected at 2.5-sigma. The inferred
dust masses and temperatures range from 0.033 to 0.24 Earth masses and 43-65 K
respectively. The frequency behavior of the opacity, tau_nu ~ nu^beta, is
relatively shallow, beta < 1. These dust properties are characteristic of
circumstellar material, most likely the debris from planetesimal collisions.
The 2 non-detections have lower temperatures, 35-38 K and steeper opacity
indices, beta > 1.5, that are more typical of interstellar cirrus. The
confirmed disks all have inferred diameters > 2'', most lie near the upper
envelope of the debris disk mass distribution, and 4 are bright enough to be
feasible for high resolution imaging.Comment: accepted by Ap
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