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291.
Polyvinyl alcohol (PVA) is a synthetic commercial polymer with the inherent hydrophilicity, thermal and chemical resistance, ecofriendly, and a high anti-fouling potential making it an attractive choice for water treatment applications, but has been less studied for oil and gas industry applications. On the other hands, nowadays nanotechnology has gained an important space within most core areas in upstream oil and gas operations. The present work, first PVA at various concentrations, was added to 5 wt% NaCl solution and then, crosslinked by formaldehyde 37% at two different concentration ratios. To compare, a nanocomposite hydrogel was fabricated in the same way with 1 wt% silica nanoparticles (NPs). Contact angle and filtration test were performed to confirm the ability of PVA hydrogel and nanocomposite hydrogel for oil and water adsorption. Following this, a rheology measurement was made to realize the gelation time of samples and their performance for water shutoff applications. Finally, an experimental flooding setup was designed to inject the fluids into carbonate plugs in order to estimate of oil and water effective permeability, and oil recovery factor (RF) before and after the PVA hydrogel and nanocomposite hydrogel injection. Both samples wettability tests showed a super-hydrophilic state for brine droplets and neutral state for synthetic oil droplets by using nanocomposite hydrogel. The flooding tests revealed that the PVA hydrogel was clogged the plug with blocking efficiency of 32.83% for water effective permeability and 14.60% for oil effective permeability. This value was calculated to be 50.37% for water effective permeability and 31.36% for oil effective permeability in the case of nanocomposite hydrogel injection. Oil RF was also reported to be 64.58% after injecting PVA hydrogel which was higher than nanocomposite hydrogel injection with RF of 52.08%. 相似文献
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293.
Vaferi Kourosh Vajdi Mohammad Nekahi Sanam Nekahi Sahar Sadegh Moghanlou Farhad Azizi Shahla Shahedi Asl Mehdi 《Microsystem Technologies》2023,29(1):141-156
Microsystem Technologies - The problem of generating a high amount of heat in microelectronic equipment should be minimized properly. Allowing systems to run for long periods of time in high... 相似文献
294.
Abbas Moghim Maisam Jalaly Sadegh Sadeghzadeh 《International Journal of Applied Ceramic Technology》2022,19(3):1669-1677
In the first stage of this work, the master nanocomposite of niobium carbide (NbC)–Cu (ceramic-based nanocomposite) was synthesized by a mechanically induced magnesiothermic combustion in the Nb2O5/CuO/Mg/C system. Ignition time in this system was recorded to be ∼28 min of milling. In the second stage, appropriate amounts of NbC–Cu nanocomposite powder were mixed with pure copper powder to prepare Cu-based nanocomposite with 0, 5, 10, 15, and 20 volume fraction of NbC. The final metal matrix nanocomposite powder was sintered by spark plasma sintering method. The density of nanocomposite specimens decreased with increasing the percentage of NbC nanoparticles, while the microhardness of specimens increased with increasing nano-NbC content. Regarding the tensile test, the sample Cu–10 vol.% NbC nanocomposite with a strength of 372 MPa (∼63% higher than that of nonreinforced copper) was the best composition, and the nanocomposite strength decreased at higher NbC concentrations, mostly due to the agglomeration and nonhomogeneous distribution of reinforcing nanoparticles. 相似文献
295.
Heejin Lee Sadegh Papari Giulio Bernardini Riccardo Gallorini Luca Rosi Franco Berruti 《加拿大化工杂志》2023,101(3):1271-1285
The objectives of this study were to examine how to recycle cup waste efficiently and effectively and to determine if cup waste can be converted into liquid, solid, and gas value-added products by slow pyrolysis. The characteristics and potential utilizations of the pyrolysis products were investigated. The study included the effects of temperature, heating rate, and different feedstocks. The yield of pyrolysis oil derived from cup waste increased from 42% at 400°C to 47% at 600°C, while the yield of char decreased from 26% at 400°C to approximately 20% at 600°C. Acetic acid and levoglucosan were identified as the main components of the pyrolysis oil. The char obtained at 500°C was physically activated at 900°C for 3 h with CO2. The adsorption capacity of the activated char was investigated with model compounds, such as methyl orange, methylene blue, ibuprofen, and acetaminophen. The results showed that the adsorption capacity of the activated char was similar to that of commercial activated carbon produced from peat. The higher heating value of the produced gas stream calculated at 400°C was 19.59 MJ/Nm3. Also, conventional slow pyrolysis (CSP) and microwave-assisted pyrolysis (MAP) technologies were compared to determine the differences in terms of products yields, composition and characteristics of the pyrolysis oil, and their potential applications. The CSP yields higher liquid products than MAP. Also, the pyrolysis oil obtained from the CSP had significantly more levoglucosan and acetic acid compared to that of the MAP. 相似文献
296.
Iman Sahafnejad-Mohammadi Sadegh Rahmati Najmeh Najmoddin Mahdi Bodaghi 《大分子材料与工程》2023,308(5):2200558
Bone shows a radial gradient architecture with the exterior densified cortical bone and the interior porous cancellous bone. However, previous studies presented uniform designs for bone scaffolds that do not mimic natural bone's gradient structure. Hence, mimicking native bone structures is still challenging in bone tissue engineering. In this study, a novel biomimetic bone scaffold with Haversian channels is designed, which approximates mimicking the native bone structure. Also, the influence of adding graphene oxide (GO) to polycaprolactone (PCL)-based scaffolds are investigated by preparing PCL/GO composite ink containing 0.25% and 0.75% GO and then 3D printing scaffolds by an extrusion-based machine. Scanning electron microscopy (SEM) is used for morphological analysis. SEM reveals good printability and interconnected pore structure. The contact angle test shows that wettability reinforces with the increase of GO content. The mechanical behavior of the scaffolds under compression is examined numerically and experimentally. The results indicate that incorporation of GO can affect bone scaffolds' Young's modulus and von Mises stress distribution. Moreover, the biodegradation rates accelerate in the PCL/GO scaffolds. Biological characterizations, such as cell growth, viability, and attachment, are performed utilizing osteoblast cells. Compared to pure PCL, an enhancement is observed in cell viability in the PCL/GO scaffolds. 相似文献
297.