The phrase "a direct indication" is correct and usable in written English.
It can be used when referring to a clear or explicit sign or signal about something.
Example: "The sudden drop in temperature was a direct indication that winter was approaching."
Alternatives: "a clear sign" or "an explicit signal."
The result was what was known as a the flying spot indicator, a single selected target showing a direct indication of the target's relative position.
Even though mass loss is not a direct indication of molecular weight decline [ 23], it is still a good indicator of the relative degradation rates of the polymers and, as such, it can be approximated that polymers with a higher ratio of ethyl glycinato substitution degrade less quickly than those with increased levels of ethyl 2- O-glycyl) lactate.
This value varies between 0 and 1 is a direct indication of the efficiency of the line; 1 being the optimal value which indicates no idle time is found.
"Your sugar cravings are a direct indication that sugar is at work destroying your body".
The shapes of pillows in ancient basalts provide both a direct indication of depositional top and proof of underwater eruption.
This decrease in the currents is a direct indication of the ionic conductivity.
Note the difference in Y axis which are a direct indication of amounts.
Calendar life performance is a direct indication of irreversible self-discharge loss.
The condition of the compressor oil is therefore a direct indication of the physical and chemical cleanliness of the system.
In addition, the size of the peaks in the spectrum is a direct indication of the amount of material present.
While most research concerning thermoelectrics has focused on the enhancement of the thermoelectric figure of merit, zT, the $/W is a direct indication of its practical use.
