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Feasibility of Proppant Flowback Control by Use of Resin-coated Proppant
Full text linkProppant flowback is a problem in Xinjiang oilfield. It decreases production rate of a fractured oil well, corrodes surface and downhole facilities and increases production costs. Curable resin-coated sand is a common technique to control proppant flowback. This article presents an experimental investigation whether it is feasible to control proppant flowback by use of resin-coated sand and whether resin-coated sand has a negative effect on proppant pack conductivity. It included two kinds of experiments, Proppant flowback experiment measured critical flow rate while the Proppant pack conductivity one measured proppant conductivity. The experimental results of proppant flowback show that the critical flow rate of resin-coated sand is far greater than that of common sand which means proppant flowback would not happen by resin-coated sand tail-in. Compared to Xinjiang sand conductivity, resin-coated sand conductivity is far smaller though it declines slightly which means use of resin-coated sand would lead to conductivity loss and sequentially results in production impairment. Experimental results show that it is feasible to control proppant flowback by use of resin-coated sand and resin-coated sand would affect fracture conductivity of a fractured oil well. Based on the experimental results, resin-coated proppant conductivity can be improved by use of resin-coated ceramic or liquid-resin-coated proppant. The achievements can give a direction towards how to select a resin-coated proppant and how to improve resin-coated proppant
On the Distribution of the Prime Numbers
Full text linkThis research explores the distribution of prime numbers, which are a fundamental topic in number theory. The study originated from the author\u27s fascination with mathematics and the desire to discover something novel. The research proposes that the distribution of prime numbers follows a regular pattern starting from the number 2. The author suggests that prime numbers can be obtained by dividing certain even numbers that have four factors by the number 2, resulting in prime numbers in sequential order. This hypothesis was tested and confirmed through the practical application of the proposed mathematical formula. Additionally, the study found that even numbers greater than or equal to 8, with six or more factors, produce complex numbers. Thus, this research provides two main contributions: firstly, a mathematical formula for the distribution of prime numbers, and secondly, a formula for the distribution of complex numbers. These findings have potential applications in various mathematical fields, including cryptography and problem-solving in number theory
Structure Property and Performance of Polymeric Foams: A Review
Full text linkThis work covered essential technological progress in all the aspects of polyurethane foam growth, including cell nucleation and stability. The work also included developing an understanding of controlling cell morphology, size, and shape and improving closed and open-cell content. This necessitated a grasp of the character of surfactant catalysts, which also helps control the development of polyurethane foams. Learn the fundamentals of polymer physics and materials science to understand how the viscosity of polymeric matter impacts the most recent performance attributes of various flexible foams, including high elasticity, flex sheet stock, and viscoelasticity
Quasi-Static Compression and Microstructural Characterization of Polyurethane Foams for Potential Use in Shock Absorbers
Full text linkThis study focuses on the detailed characterization of modified polyurethane foams, emphasizing their quasi-static compression behaviour and microstructural properties, to evaluate their potential application in shock-absorbing systems. Through systematic synthesis, we produced various formulations of polyurethane foams. We subjected them to comprehensive quasi-static compression tests to understand their deformation and energy absorption characteristics under controlled loading conditions. Concurrently, microstructural analyses were conducted to elucidate the relationship between the cellular architecture of the foams and their mechanical responses. Although the foams were not directly integrated into shock absorbers, the findings lay a foundational understanding of how their structural and compositional variations influence performance metrics crucial for shock absorption applications. This research contributes to the broader knowledge base required for the future design and optimization of polyurethane foam-based shock absorbers, highlighting critical areas for further investigation and development
Fuzzy Soft Sets and its Application to Decision Making: A Short Case Study Involving the Health Sector
Full text linkThe health sector faces uncertainty and complex decision-making scenarios, making traditional analytical tools insufficient. The fuzzy soft set theory has emerged as a powerful framework for modeling and reasoning with uncertain information, with promising applications in the health domain. This project explores the application of fuzzy soft sets in various decision-making processes in the health sector, including medical diagnosis, disease classification, treatment planning, risk assessment, patient stratification, and predictive modeling. The study reviews historical development of fuzzy set theory and its extension to soft sets, discussing challenges, limitations, and future research directions. The findings aim to contribute to the growing body of knowledge on the practical relevance and potential of fuzzy soft set theory in addressing healthcare decision-making needs
Only the Greenhouse Gas, Water Vapor, Measurably Warms the Earth
Full text linkData is available for the 61 greenhouse gases (GHGs) in Table 2.14 of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) to calculate their contribution to global warming in degrees Celsius. The procedure is described in the recently published study Reliable Physics Demand Revision of the IPCC Global Warming Potentials. In the current study, the contribution was calculated for each 61 GHG. The sum of the contributions of the 61 GHGs was 0.00833oC out of 26oC, which, for this example, is the difference in temperature between Pond Inlet and Amsterdam. This amount of temperature is too small to measure. Thus, with all other GHGs except water vapor eliminated as warming gases, water vapor is the only GHG that causes measurable warming of the Earth’s atmosphere. This is the exact result of the mathematical model of the Earth’s atmosphere developed in 1904 by Willis Carrier, i.e., the psychrometric chart, which is now a computer program, i.e., Humidair. Thus, the two methods used 120 years apart are robust and give the same result, confirming the unique role of water vapor in the temperature of Earth’s atmosphere and the virtually non-temperature role of the 61 GHGs
Antioxidant Effect of a Combination of S-Acetyl-L-Glutathione, Vitamin E, Silybum Marianum on Hepatic Cells under Oxidative Stress: An In Vitro Study
Full text linkOxidative stress plays a key role in the pathogenesis of liver diseases and can be involved in the inflammatory process of liver cells. The aim of this vitro study is to assess the antioxidant efficacy of three distinct components (fermented S-Acetyl -L-glutathione, Silybum marianum (L.) Gaern. and vitamin E all-rac-alpha-tocopheryl acetate) both individually and in combination (Glutasyl product). In addition, we also evaluated the combined antioxidant effect of the three ingredients on human hepatic cells subjected to oxidative stress induced by H2O2 treatment.
The results showed the dose-dependent antioxidant potential of the three components suggesting promising applications in medical contexts. The synergistic antioxidant effects observed for the Glutasyl was more than the individual components. Additionally, Glutasyl showed not-toxic activity on human hepatocytes and it could be considered useful in mitigating cytotoxicity induced by oxidative stress
Relation between Total Geodesic Submanifolds and Tachibana Operator for Lorentzian Sasakian Space Forms
No full textIn this article, total geodesic submanifolds of a Lorentzian Sasakian Space forms are characterized according to the Tachibana tensor with the help of some special curvature tensors. The behavior of total geodesic submanifolds of the Lorentzian Sasakian Space Forms has determined under some important conditions
Sensitivity of Daphnia magna: Acute Toxicity Evaluation of 22 Metals
Full text linkIntroduction: All potentially toxic metals in the environment can be discharged in the aquatic ecosystems. Daphnia magna is one of the most sensitive species to toxic chemicals in water and is frequently used in toxicological research and environmental monitoring.
Material and Methods: Acute toxicity test for twenty-two metals (Pb, Cd, Ni, Hg, Cu, Fe, Co, As, Cr, Mn, Zn, Al, Pd, Na, K, Mo, Mg, Ca, W, Ir, Ti, Ag) was carried out for Daphnia magna. These elements were checked and ranked in terms of decreased immobilization (EC50) after 24Hr and 48Hr and compared with previous studies.
Results: The results were categorized into four groups by the 48Hr EC50s values: highly toxic groups (Ag, Hg, Cu, Cd, Pd) [EC50 < 100 μg.l-1], moderately toxics groups Cr, Fe, Ni, Zn and Pb) [100 μg.l-1<EC50 < 1 000 μg.l-1], low toxic groups (Al, Mn, As, Ti, Co, W and Ir) [1000 μg.l-1<EC50 < 100000 μg.l-1], and minimally toxic groups (Na, Mg, K, Ca, and Mo) [EC50 > 100 000 μg.l-1]. Correlation coefficients (r) between EC values and eight physicochemical properties were also examined. The results obtained in this study were weak.
Conclusion: This work adds and confirm data about the toxicities of metals in aquatic ecosystems by using a rapid biomonitoring test
Protective Effect of Curcuminoids Consumption on Cadmium-Induced Testicular Injury in Albino Rats
No full textThis study evaluated the protective effects of curcuminoids against cadmium-induced testicular injury in Albino rats. Male albino rats were divided into nine groups, group 1 (control), groups 2-4 received 120 mg/kg, 240 mg/kg, and 360 mg/kg curcuminoids daily for 28 days without testicular injury. Group 5 received 20 mg/kg cadmium chloride (CdCl2) solution every other day for 28 days (positive control), while group 6 received 20mg/kg CdCl2 + 240 mg/kg curcuminoids every other day for 28 days. Group 7 received 20mg/kg CdCl2 every other day for 28 days, then treated with 240 mg/kg for 14 days. Group 8 received 20 mg/kg CdCl2 solution every other day for 28 days, then treated with 240 mg curcuminoids for 28 days. Group 9 received 20 mg/kg CdCl2 solution every other day for 28 days and left to recover 28 days. Serum and seminal plasma malondialdehyde, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase were assayed using Spectrophotometry technique. Semen analysis was determined microscopically. Sperm motility and count were significantly reduced, acrosome defect and percent abnormal sperm morphology were increased among the positive control group when compared with negative control group (p<0.05). Serum GPX, GSH, and SOD, semen GPx , GSH and SOD were significantly reduced (p<0.001), while MDA was significantly increased (p<0.001) in CdCl2 administered rats than negative control. The supplementation of Curcumins resulted in the improvement of sperm quality indices in a dose-dependent manner. Curcumin supplementation may significantly reverse the adverse effects of cadmium chloride testicular injury