Factors uncontrollable

There are two categories of uncontrolled factors. Uncontrolled influences might arise from either unknown factors or known factors that cannot be controlled. The eventual impurity of a reagent is an example of an unknown factor. The changing quality... 

A "factor is defined as one of the variables contributing to a particular result or situation. It is an input variable that has (or may have) an influence upon the system. Factors can be controlled or uncontrolled by the experimenter. Controlled factors are identified experimental conditions that can be fixed (e.g. temperature 25 °C) or settled at will (pH 5/pH 7). Each one of these different values is called "a level of the factor . Uncontrolled factors are unidentified variables or conditions that the experimenter voluntarily decides not to control (room temperature, atmospheric pressure, ionic strength, etc.). Uncontrolled factors are undesirable in experimental situations because their influence cannot always be easily or unambiguously detected or evaluated. Experimental error can be considered as an uncontrolled factor. 

This provides the best estimate of the expected standard deviation for results obtained by several laboratories, due to the effects of small changes in uncontrolled or poorly controlled factors. If this standard deviation is unacceptably large, then the procedure may be modified to bring under greater control those factors whose levels have the greatest effect on the response. 

Acrylate and methacrylate polymerizations are accompanied by the Hberation of a considerable amount of heat and a substantial decrease in volume. Both of these factors strongly influence most manufacturing processes. Excess heat must be dissipated to avoid uncontrolled exothermic polymerizations. In general, the percentage of shrinkage decreases as the size of the alcohol substituent increases on a molar basis, the shrinkage is relatively constant (77). 

Control of supersaturation is an important factor in obtaining crystal size distributions of desired characteristics, and it would be useful to have a model relating rate of cooling or evaporation or addition of diluent required to maintain a specified supersaturation in the crystallizer. Contrast this to the uncontrolled situation of natural cooling in which the heat transfer rate is given by... 

Relative width of region of unreliable reaction (5) was estimated as the ratio of difference between maximum and minimal concentrations to minimal concentration in this region. The test-system containing Co [Fe(CN)g] is the most resistant to uncontrolled factors, the lowest detection limit characterizes a film with Ni,[Fe(CN)J. The possibility of test-films application for quantitative determination of nitroxoline is testified. 

Another factor that can contribute to the low release force provided by a release material is the presence of a mechanically weak boundary layer at the surface of the release coating [40,41]. Upon peeling the PSA from the release coating, the locus of failure is within this mechanically weak layer, resulting in transfer of material to the adhesive and a subsequent loss in adhesion of the PSA. Although the use of a weak boundary layer may not be the preferred method of achieving low adhesion for PSA release coatings, it can be useful if the amount of transfer is consistent and kept to a minimum [42]. However, in many cases the unintentional or uncontrolled transfer of a weak boundary layer to a PSA results in an undesirable loss in readhesion. 

Sampling and analytical error (SAE) A numerical factor used in analytical methods to account for uncontrollable errors. Its value is taken into consideration in the determination of whether the exposures are within acceptable limits. 

Inhibition of hematopoietic growth factors Imatinib (Glivec ) is applied to treat chronic myeloid leukemia in Philadelphia-chromosome positive patients. In these patients, translocation of parts of chromosomes 9 and 22 results in the expression of a fusion protein with increased tyrosine kinase activity, called Bcr-Abl. Imatinib is a small Mw inhibitor selective for the tyrosine kinase activity of Bcr-Abl. Thereby, it inhibits the Bcr-Abl induced cell cycle progression and the uncontrolled proliferation of tumor cells. 

In rare cases of a systemic release, kinins have the potential to cause severe hypotension. Uncontrolled activation of the contact system (Fig. 3) is thought to trigger a massive formation of kinins under certain pathological conditions [3]. For instance, this situation is seen in patients with underlying diseases such as systemic inflammatory response syndrome (SIRS) due to sepsis or trauma. SIRS progression is accompanied by depletion of contact system factors and low levels of H-kininogen and plasma kallikrein are indicative of a... 

The biodegradation of surfactants is studied by means of many different tests and sometimes under different conditions. Some factors with significant influence on the results are uncontrollable factors and in other cases are not controllable. This causes a dispersion in biodegradability data that makes comparisons difficult. For this reason only general conclusions can be obtained from the data available. Swisher carried out an exhaustive collection of available data in his complete study on surfactant biodegradation [385]. Some basic and significant features of biodegradation of alcohol and alcohol ether sulfates are discussed below. 

A third reason is due to the influence of external factors, which often play a more important role than the factors that characterise the chemical nature of the reaction. All reactions can be regarded as dangerous (or not dangerous) at this stage. This means that most of the time it is the ambient conditions that make chemical reactions uncontrollable. 

Factors that increase the risk of bleeding must be evaluated before thrombolytic therapy is initiated (i.e., recent surgery, trauma or internal bleeding, uncontrolled hypertension, recent stroke, or intracranial hemorrhage)... 

Research also continues into the use of recombinant activated factor VII (rFVIIa) as an adjunctive agent to treat uncontrolled hemorrhage. Initial experiences with rFVIIa show that it can decrease transfusions, though large studies have not been performed.41 Ultimately, pharmacoeconomic... 

Many of the coagulation factors measured by global coagulation tests have limited stability, and the time and temperature of storage of sample will affect their measurements. Concepts of analyte stability and half-life in plasma extend to markers measured by immunoassay. Markers of platelet activation are affected by artifactual activation in vitro upon collection of the blood specimen. This section will highlight some of the nonanalytical variables that, if uncontrolled, can lead to spurious results and thus affect the interpretation of laboratory data. 

Hours of Operation (h) Uncontrolled Control Efficiency (%) Emission Factor (lb HCI/tons Processed)b ... 

The filtration coefficient is determined by the surface area and permeability of the filtration barrier. An increase in the filtration coefficient leads to an increase in GFR if the filtration coefficient decreases, then GFR decreases. However, this factor does not play a role in the daily regulation of GFR because its value is relatively constant under normal physiological conditions. On the other hand, chronic, uncontrolled hypertension and diabetes mellitus lead to gradual thickening of the basement membrane and therefore to a decrease in the filtration coefficient and GFR, and impaired renal function. 

The above described landfill refers to a highly controlled landfill site with emission precaution measures. However, in less controlled conditions DEHP emissions might occur. Therefore, an additional assumption is made for emissions of DEHP from uncontrolled landfill. The same yearly emission factor is used as for the use phase of the floor covering, assuming a time period of 30 years instead of 15 years. 

The comparison of aquatic ecotoxicity scores between the scenarios is completely dominated by the assumed emission of DEHP from the (uncontrolled) landfill site. If an emission is assumed the score for aquatic ecotoxicity will increase substantially (a factor 2). 

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