Ambient parameters

The correlations of liquid viscosities with structural and ambient parameters pose difficult problems. Yaws recommended the following equation for the viscosity at 25 °C for paraffins ... 

In the short term, minimal noise and short-term drift are the goals. Noise has a detrimental effect on the LOD and on the precision of the response. Short-term drift, often associated with short-term changes in ambient parameters such as temperature, pressure, and relative humidity, can exceed oscillator noise, in which case drift dictates the LOD. While it is possible to partially compensate for noise by averaging several consecutive data points, this is mote difficult for short-term drift. 

A recent round-robin test by Labnet [12] shows tolerances of 4% on part load efficiency and around 2% on full load efficiency. The implementing ecodesign measures are very sensitive to the performance of a central heating boiler system and so it is very important to increase the quality level of test institutes in terms of fuel quality, ambient parameters, and measure instruments. 

The following parameters and processing variables affect the electrospinning process (i) system parameters such as molecular weight, molecular weight distribution and architecture (branched, linear, etc.) of the polymer, and polymer solution properties (viscosity, conductivity, dielectric constant, and surface tension, charge carried by the spinning jet) and (ii) process parameters such as electric potential, flow rate and concentration, distance between the capillary and collection screen, ambient parameters... 

The parameters involved in the electrospinning processes that affect the nanofiber geometry and structure can be divided into two groups (i) System parameters such as polymer molecular weight, molecular weight distribution, polymer architecture (branched, linear), concentration of the polymer solution and its properties, including viscosity, electrical conductivity, and surface tension and (ii) Process parameters such as applied electric voltage, polymer flow rate, distance between the needle tip and the collector, ambient parameters such as temperature, humidity, and air velocity in the chamber, and motion of the collector (Frenot and Chronakis 2003). 

Ambient parameters are variables with ability to affect the morphology and the formation of the electrospun nanofibers like the processing ones. However, unlike... 

Although the ambient parameters have a distinct impact on electrospun fibers, these systemic parameters present challenges for dynamic control. Furthermore, the effects of these environmental factors depend on polymer-solution combinations (ie, sensitivity to temperature, hygroscopic nature of solution and optimum vapor pressure)... 

Ambient parameters, such as solution temperature, humidity, atmosphere, and air velocity in the electrospinning chamber. 

Many parameters can influence the transformation of polymer solutions into nanofibers through electrospinning. These parameters include (a) solution properties, such as viscosity, elasticity, conductivity and surface tension (b) governing/operating variables, such as hydrostatic pressure in the capillary tube, electric potential at the capillary tip and the gap (distance between the tip and the collecting screen) and (c) ambient parameters such as solution temperature, humidity and air velocity in the electrospinning chamber. ... 

The effects of temperature and humidity as two major ambient parameters are worth noting even though electrospinning is often conducted at room temperature. Increasing solution temperature can significantly reduce mean fibre diameters, which can be attributed to its indirect effect on solvent evaporation rate and solution... 

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