Effectiveness of light pressure stroking massage on pain and fatigue of patients after coronary artery bypass graft surgery-A randomized clinical trial

زمینه و هدف: درد و خستگی از مشکلات شایع بعد از عمل بیماران تحت جراحی پیوند عروق کرونر می باشد. هدف از این مطالعه تعیین تأثیر ماساژ درمانی بر شدت درد و خستگی بعد از عمل بیماران تحت جراحی پیوند عروق کرونر بوده است. روش بررسی: در این مطالعه کارآزمایی بالینی تصادفی سازی شده، تعداد 72 نفر بیمار تحت عمل جراحی قرارگرفته عروق کرونر در بیمارستان شهید چمران شهر اصفهان، انتخاب شدند و بطور تصادفی در دو گروه مداخله و شاهد قرار گرفتند. بیماران گروه مداخله (36 نفر)، ماساژ استروک سطحی 20 دقیقه ای به مدت 4 جلسه در 4 روز پیاپی در روزهای 3 تا 6 بعد از عمل جراحی دریافت کردند و بیماران گروه شاهد تنها مراقبت های روتین را دریافت نمودند. متغیرهای درد و خستگی قبل و بعد از مداخله با استفاده از مقیاس قیاسی دیداری ثبت شدند. یافته ها: نتایج نشان داد که اختلاف معنی داری بین شدت درد و خستگی در دو گروه مداخله و شاهد بعد از انجام مداخله وجود داشته است (0/001>P). بطوریکه کاهش میانگین شدت درد و خستگی از روز اول تا چهارم بعد از عمل در گروه مداخله بیشتر از گروه شاهد بود. نتیجه گیری: استفاده از ماساژ استروک سطحی می تواند باعث کاهش درد و خستگی بعد از عمل بیماران تحت جراحی پیوند عروق کرونر شود و با توجه به سادگی و کم هزینه بودن این روش، شاید بتواند به عنوان مکمل مناسبی برای دارودرمانی و مداخلات بعد از عمل در این بیماران مورد استفاده قرار گیرد

Utilization of fine water sprays in explosion mitigation : cold trial

For the past fifty years, there has been a great deal of interest using water-based explosion suppression systems in mitigating/reducing the impact of thermal explosions and their consequential overpressures. Previous research focused on the suppression and mitigation with sprays containing droplets 200µm ≤ D32 ≤ 1000µm. The present study is focused on the mitigation of slow-moving deflagrations with speeds of less than or equal to 30 m/s. Consequently, the droplets within the spray must be small enough to extract heat in the short finite moments that the flame and droplets interact at about 0.03 ms for a 1 mm thick flame front. An apparatus was thus designed to simulate ‘partly confined and/or vented’ conditions, venting upstream of the propagating flame. Previous theoretical studies have suggested that droplets in the order of 10 µm to 20 µm will enable to mitigate combustion without relying on further droplet break up. This investigation, herewith, is presenting the full details of qualitative and quantitative analysis of using Spill Return Atomiser (SRA) to provide fine water spray. The spray cone angle was increased from 34.7˚ to 49.2˚and the exit orifice flow rate was raised from 0.295 l/min to 1.36 l/min. Increasing the flow rate provided a number of spray options ranging from 17µm ≤ D32 ≤ 29µm, with liquid volume flux of 0.011 cm³/s/cm² to 0.047 cm³/s/cm² and mean droplet velocity of 0 to 21.4 m/s, with the resulting of complete explosion mitigation qualities

Qualitative analysis of spray characteristics of impinging jets using a gelled non-Newtonian propellant simulant

The utilization of liquid and solid fuels for propulsion and combustion processes with Newtonian characteristics are widely known. However, recent studies are considering the application of shear-thinning non-Newtonian fuels as alternative simulant since they have some advantages compared to the conventional propellants although there are challenges of providing better spray performance during the corresponding process. This paper, therefore, presents the results of the experimental investigations of the “near-field” spray characteristics with utilizing imaging techniques which evaluates the sheet formation and breakup length of four different spray patterns produced by the jet impingement of a gelled non-Newtonian propellant simulant. The qualitative analysis of this study shows that the spray patterns are different compared to those that are shaped by using Newtonian liquid fuels. This could lead to supposition that the non-Newtonian rheology of the gelled propellant simulant postponed the sheet and ligaments breakup, including the mode change of the atomization. In addition, the atomization of the sheet at different flow parameters could occur due to the formation and the sheet wave instability when aerodynamic and hydrodynamic of their origin are closely considered. This was further supported by the occurrence of perforations in the sheet

Innovative drilling fluid containing sand grafted with a cationic surfactant capable of drilling high pressure and high temperature geothermal and petroleum wells

Maintaining the rheology and filtration properties of a drilling fluid plays a vital role during a drilling operation. With the current challenges of high pressure and high temperature environments, there is an urgent need to design thermally stable water-based mud systems (WBM) which are environmentally clean and economically cheap. High pressure and high temperature (HPHT) environments affect drilling fluid systems leading to degradation of additives hence reducing the efficiency of the drilling fluid. Nanotechnology has been widely used to answer questions about additive degradation, and many studies are currently being conducted on how to use nanotechnology to design smart drilling fluids. However, nanotechnology comes at a high cost, resulting in an increase in the overall drilling operation costs and the project as a all. Therefore, the effectiveness of sand particles as a replacement of commercial nanoparticles is investigated in this study as an additive for designing effective-performance water-based drilling fluids. Effective-performance drilling fluids are environmentally friendly, stable at high temperatures, and help to avoid well damage during drilling operations. The research compared sand particles, which are widely available and inexpensive to silica nanoparticles at 0.5 wt% concentration. The samples were tested at different aging temperatures. Rheological properties were measured at room temperature up to 232 °C. The performance of sand and silica nanoparticles was studied by comparing each of the nanoparticle muds with the reference mud sample, taking filtration and rheological properties as the benchmark parameters. Experimental data showed that sand particles enhanced almost all the rheological and filtration properties of the WBM compared to the reference mud. When compared to silica nanoparticles, the results showed neither statistically significant variance in plastic viscosity and yield point among the samples, with muds containing sand particles performing similarly or better. Formulation S2 (35–70 μm) demonstrated the ability to improve the rheology of WBM. At 204 °C and 232 °C, Formulation S2 (35–70 μm) filtrate loss decreased by 16.35% and 29.52%, respectively, compared to 5.66% and 11.32% by mud containing nano silica. The same mud sample decreased the mud cake thickness at the same temperatures conditions by 54.74% and 45.45%, respectively, as opposed to 36.84% and 11.81%. The new innovative mud system can be used to drill in HPHT conditions

Impact pressure distribution in flat fan nozzles for descaling oil wells

The suitability of high pressure nozzles in terms of impact upon targeted surfaces has indicated its effectiveness for the cleaning of oil production tubing scale, which has recently attracted wider industrial applications considering its efficiency, ease of operation and cost benefit. In the oil and gas production, these nozzles are now used for cleaning the scale deposits along the production tubing resulted mainly from salt crystallization due to pressure and temperature drop. Detailed characterizations of flat-fan nozzle in terms of droplet sizes and mean velocities will benefit momentum computations for the axial and radial distribution along the spray width, with the view of finding the best stand-off distance between the target scale and the spray nozzle. While the droplet sizes and the velocities determine the momentum at impact, measuring droplet sizes has been known to be difficult especially in the high density spray region, still laboratory characterization of nozzles provides a reliable data especially avoiding uncontrollable parameters. While several researches consider break up insensitive to the cleaning performance, this research investigates the experimental data obtained using PDA (phase doppler anemometry) which led to established variation in momentum across the spray width thus, non-uniformity of impact distribution. Comparative model was then developed using Ansys Fluent code, which verifies the eroded surfaces of material using the flat-fan atomizer to have shown variability in the extent of impact actions due to kinetic energy difference between the center and edge droplets. The study’s findings could be useful in establishing the effect of droplet kinetic energies based on the spray penetration, and will also add significant understanding to the effect of the ligaments and droplets, along the spray penetration in order to ascertain their momentum impact distribution along the targeted surface

The effects of dissolved Sodium Chloride (NaCl) on well injectivity during CO2 storage into saline aquifers

Saline aquifer formations seem to be promising candidates for carbon dioxide (CO2) storage due to their wide availability as well they have large storage capacity. Once CO2 is injected into saline aquifer variety of processes will take place, among of them is the formation dry out and salt precipitation phenomenon, the main driver of this phenomenon is the salinity in the form of Halite (NaCL), this considers a major challenge of CO2 injection into saline aquifers, it causes the risk of formation clogging and will effect on the well injectivity and lead to pressure build up. The selected candidate for carbon dioxide (CO2) storage should meet the technical requirements of sealing integrity, storage capacity (potential) and containment. After the commencement of carbon dioxide (CO2) injection into high salinity formations, formation dry out due to salt precipitation in the near wellbore will take place and this cause permeability and injectivity reduction. This work will focuses on experimental work. The experimental work investigations studied the effectiveness dilution of high sodium chloride NaCl solutions with sea water and its contribution in improving the injectivity. After saturating the sandstone core samples with different brine solutions, linear core flow tests using nitrogen gas (N2) were carried out. The saturated samples in diluted solutions for castlegate sandstone sample showed increase in the flow rate from 4 L/min at 50 psi to 5 L/min at the same pressure, experimentally it was confirmed that dilution of brine solutions by seawater will assist in improving the sandstone core samples porosity , permeability and the injectivity. Keywords- CO2 storage, seawater, CO2/Brine/Rock, Salinity, porosity, permeability CO2 injectiviy