5 research outputs found
A study of the properties of an oil-based drilling fluid with using emulsifier EM-4
The issue of maintaining the potential productivity of the well is one of the most urgent tasks of the oil and gas industry nowadays. Due to the development of deposits with complex deposits and low-permeability productive layers, the issues of increasing the flow rate of wells due to the qualitative opening of reservoirs were of fundamental importance. The drilling fluid with an oil base (OBM) does not adversely affect the properties of oil and gas collectors, also it has good lubricating properties, reducing the wear of drill bits and bits. This paper is devoted to comparing the properties of drilling muds prepared using the industrial emulsifier Cleave FM and the new synthesized emulsifier EM-4. Emulsifier EM-4 is a solution of N- (2-hydroxyethyl) amides of fatty acids in a mixture of mono- and diglycerides of fatty acids
Führen computerunterstütze (IT)-Interventionen zur Verbesserung der Medikamentensicherheit in der Allgemeinmedizin-Praxis?: eine systematische Übersichtsarbeit von randomisiert kontrollierten Studien
Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom
Intravascular Enhancement With Identical Iodine Delivery Rate Using Different Iodine Contrast Media in a Circulation Phantom
Purpose: Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR. Materials and Methods: A circulation phantom with a low-pressure venous compartment and a high-pressure arterial compartment simulating physiological circulation parameters was used (heart rate, 60 beats per minute; stroke volume, 60 mL; blood pressure, 120/80 mm Hg). Maintaining a constant IDR (2.0 g/s) and a constant total iodine load (20 g), prewarmed (37 degrees C) contrast media with differing iodine concentrations (240-400 mg/mL) were injected into the phantom using a double-headed power injector. Serial computed tomographic scans at the level of the ascending aorta (AA), the descending aorta (DA), and the left main coronary artery (LM) were obtained. Total amount of contrast volume (milliliters), iodine delivery (grams of iodine), peak flow rate (milliliter per second), and intravascular pressure (pounds per square inch) were monitored using a dedicated data acquisition program. Attenuation values in the AA, the DA, and the LM were constantly measured (Hounsfield unit [HU]). In addition, time-enhancement curves, aortic peak enhancement, and time to peak were determined. Results: All contrast injection protocols resulted in similar attenuation values: the AA (516 [11] to 531 [37] HU), the DA (514 [17] to 531 [32] HU), and the LM (490 [10] to 507 [17] HU). No significant differences were found between the AA, the DA, and the LM for either peak enhancement (all P > 0.05) or mean time to peak (AA, 19.4 [0.58] to 20.1 [1.05] seconds; DA, 21.1 [1.0] to 21.4 [1.15] seconds; LM, 19.8 [0.58] to 20.1 [1.05] seconds). Conclusions: This phantom study demonstrates that constant injection parameters (IDR, overall iodine load) lead to robust enhancement patterns, regardless of the contrast material used. Higher iodine concentration itself does not lead to higher attenuation levels. These results may stimulate a shift in paradigm toward clinical usage of contrast media with lower iodine concentrations (eg, 240 mg iodine/mL) in individual tailored contrast protocols. The use of low-iodine concentration contrast media is desirable because of the lower viscosity and the resulting lower injection pressure