The phrase "ultra low level" is correct and can be used in written English.
It usually refers to an amount or level that is extremely low or minimal. For example, "The noise level in the library was an ultra low level, so I was able to concentrate on my studies."
There also are growing worries about the build-up in liquidity and the ultra low level of interest rates in most economies.
The renewed interest in ULSD research is driven by the need, to have a comprehensive understanding of the various factors influencing deep desulfurization of diesel to the ultra low level as well as to find cost-effective ways for ULSD production.
Interest rates have been kept at the ultra low level of 0.5% since 2009 in an attempt to bolster the economy.
Aliquots of known weight of this liquid were then assessed for their tritium content by liquid scintillation counting (1220 QUANTULUS Ultra Low Level Liquid Scintillation Spectrometer, PerkinElmer Inc).
Aliquots of known weight were then assessed for their carbon-14 content by liquid scintillation counting (1220 QUANTULUS Ultra Low Level Liquid Scintillation Spectrometer, PerkinElmer Inc).
These Ultra Low Level Lasers (ULLL) working in pulsed or continuous emission mode are capable of eliciting significant biological effects, possibly via photostimulation [ 10].
Sulfur content of diesel fuel has been cut down to ultra low levels by environmental regulation in many countries with the aim of reducing diesel engine's harmful emissions and improving air quality.
The challenge is to develop a water purification technology which will be effective at removing these contaminants simultaneously and reducing their concentrations to ultra low levels from waste water.
The program to develop a catalytic combustion technology that can achieve ultra low levels of NOx, CO and unburned hydrocarbons (UHCs), applicable to a wide range of gas turbine systems and with long term durability is described.
Interest rates are likely to rise gradually from their current ultra low levels in the rich countries - particularly in the US and the UK.
Morgenstern, U. & Taylor, C. B. Ultra low-level tritium measurement using electrolytic enrichment and LSC.
