123 research outputs found
Liquid loading in wellbores and its effect on cleanup period and well productivity in tight gas sand reservoirs
Tight gas reservoirs normally have production problems due to very low matrix permeability and significant damage during well drilling, completion, stimulation and production. Therefore they might not flow gas to surface at optimum rates without advanced production improvement techniques. After well stimulation and fracturing operations, invaded liquids such as filtrate will flow from the reservoir into the wellbore, as gas is produced during well cleanup. In addition, there might be production of condensate with gas. The produced liquids when loaded and re-circulated downhole in wellbores, can significantly reduce the gas pro-duction rate and well productivity in tight gas formations.This paper presents assessments of tight gas reservoir productivity issues related to liquid loading in wellbores using numerical simulation of multiphase flow in deviated and horizontal wells. A field example of production logging in a horizontal well is used to verify reliability of the numerical simulation model outputs. Well production performance modelling is also performed to quantitatively evaluate water loading in a typical tight gas well, and test the water unloading techniques that can improve the well productivity. The results indicate the effect of downhole liquid loading on well productivity in tight gas reservoirs. It also shows how well cleanup is sped up with the improved well productivity when downhole circulating liquids are lifted using the proposed methods
Vulnerability considerations for power line communication's supervisory control and data acquisition
Due to the increasing importance of communication networking, the power line (PL) channel has been considered as a good candidate for the communication medium. Power line communications (PLC) term stands for the technologies for the data communication over the electrical power supply network. The PL channels were not designed to transmit high speed data; therefore, they exhibit hostile medium for communication signal transmission. There are many factors such as noises, attenuation, distance, etc. affecting the quality of the transmission over PL channels. This paper presents PL model in the first sections of the work. Then it covers the security assessment of the PL system in the supervisory control and data acquisition (SCADA) context
Presence of Caffeic Acid in Flaxseed Lignan Macromolecule
Phenolic compounds were extracted from defatted flaxseeds using ethanol-dioxane (1:1, v/v). The crude extract obtained was purified using Amberlite XAD-16 column chromatography with water and methanol as mobile phases. RP-HPLC and SE-HPLC showed a lignan macromolecule (LM) as a dominant phenolic compound in the purified extract. After the alkaline hydrolysis of LM caffeic acid glucoside (CaAG) was isolated using a semi-preparative HPLC and its structure was confirmed by LC-ESI-MS. In LM of the investigated flaxseed, one molecule of caffeic acid corresponded with five molecules of p-coumaric acid and two molecules of ferulic acid. The presence of caffeic acid in the lignan molecule might be very beneficial due to its high antioxidant activity
Plant Food Delphinidin-3-Glucoside Significantly Inhibits Platelet Activation and Thrombosis: Novel Protective Roles against Cardiovascular Diseases
Delphinidin-3-glucoside (Dp-3-g) is one of the predominant bioactive compounds of anthocyanins in many plant foods. Although several anthocyanin compounds have been reported to be protective against cardiovascular diseases (CVDs), the direct effect of anthocyanins on platelets, the key players in atherothrombosis, has not been studied. The roles of Dp-3-g in platelet function are completely unknown. The present study investigated the effects of Dp-3-g on platelet activation and several thrombosis models in vitro and in vivo. We found that Dp-3-g significantly inhibited human and murine platelet aggregation in both platelet-rich plasma and purified platelets. It also markedly reduced thrombus growth in human and murine blood in perfusion chambers at both low and high shear rates. Using intravital microscopy, we observed that Dp-3-g decreased platelet deposition, destabilized thrombi, and prolonged the time required for vessel occlusion. Dp-3-g also significantly inhibited thrombus growth in a carotid artery thrombosis model. To elucidate the mechanisms, we examined platelet activation markers via flow cytometry and found that Dp-3-g significantly inhibited the expression of P-selectin, CD63, CD40L, which reflect platelet α- and δ-granule release, and cytosol protein secretion, respectively. We further demonstrated that Dp-3-g downregulated the expression of active integrin αIIbβ3 on platelets, and attenuated fibrinogen binding to platelets following agonist treatment, without interfering with the direct interaction between fibrinogen and integrin αIIbβ3. We found that Dp-3-g reduced phosphorylation of adenosine monophosphate-activated protein kinase, which may contribute to the observed inhibitory effects on platelet activation. Thus, Dp-3-g significantly inhibits platelet activation and attenuates thrombus growth at both arterial and venous shear stresses, which likely contributes to its protective roles against thrombosis and CVDs
The effect of acceptance and commitment therapy on insomnia and sleep quality: A systematic review
Background Acceptance and Commitment Therapy (ACT), as a type of behavioral therapy, attempts to respond to changes in people’s performance and their relationship to events. ACT can affect sleep quality by providing techniques to enhance the flexibility of patients’ thoughts, yet maintaining mindfullness. Therefore, for the first time, a systematic review on the effects of ACT on sleep quality has been conducted. Methods This systematic review was performed to determine the effect of ACT on insomnia and sleep quality. To collect articles, the PubMed, Web of Science (WOS), Cochrane library, Embase, Scopus, Science Direct, ProQuest, Mag Iran, Irandoc, and Google Scholar databases were searched, without a lower time-limit, and until April 2020. Results Related articles were derived from 9 research repositories, with no lower time-limit and until April 2020. After assessing 1409 collected studies, 278 repetitive studies were excluded. Moreover, following the primary and secondary evaluations of the remaining articles, 1112 other studies were removed, and finally a total of 19 intervention studies were included in the systematic review process. Within the remaining articles, a sample of 1577 people had been assessed for insomnia and sleep quality. Conclusion The results of this study indicate that ACT has a significant effect on primary and comorbid insomnia and sleep quality, and therefore, it can be used as an appropriate treatment method to control and improve insomnia
Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design
<p>Abstract</p> <p>Background</p> <p>Obesity leads to an increase in inflammation and insulin resistance. This study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people.</p> <p>Methods</p> <p>Using a randomized crossover design, nine obese glucose intolerant people consumed 40 g ground flaxseed or 40 g wheat bran daily for 12 weeks with a 4-week washout period. Plasma inflammation biomarkers (CRP, TNF-α, and IL-6), glucose, insulin, and thiobaribituric acid reactive substance (TBARS) were measured before and after of each supplementation.</p> <p>Results</p> <p>Flaxseed supplementation decreased TBARS (p = 0.0215) and HOMA-IR (p = 0.0382). Flaxseed or wheat bran supplementation did not change plasma inflammatory biomarkers. A positive relationship was found between TBARS and HOMA-IR (r = 0.62, p = 0.0003).</p> <p>Conclusions</p> <p>The results of the study weakly support that decreased insulin resistance might have been secondary to antioxidant activity of flaxseed. However, the mechanism(s) of decreased insulin resistance by flaxseed should be further determined using flaxseed lignan.</p
Meanings attributed by family members in pediatrics regarding their interactions with nursing professionals
Abstract OBJECTIVE Understanding the meanings attributed by family caregivers of children in hospital environments about their interactions with nursing professionals. METHODS This qualitative study used Symbolic Interactionism as a theoretical reference and Grounded Theory as the methodological framework. It was carried out in a Pediatrics Center in southern Brazil, in the first half of 2013. Participants were 15 family caregivers of hospitalized children. Data were collected through interviews and submitted to open and axial analysis. RESULTS Interactions with the nursing team enable family to trust or distrust in the provided child care and to positively evaluate the care received. CONCLUSION Interactions between family members and the nursing team contribute to the significance attributed by the family to the nursing care received by the child. Nurses should be aware of the attitudes of the nursing team regarding the child and their family, prioritizing humanized care
Enhancing the HVRT and LVRT Capabilities of DFIG-based Wind Turbine in an Islanded Microgrid
Doubly fed induction generator (DFIG) based wind turbines are very sensitive to grid voltage variations. Therefore, low-voltage-ride-through (LVRT) and high-voltage-ride-through (HVRT) capabilities are employed to improve DFIG performance during grid faults and voltage swell events. In this paper, a superconducting magnetic energy storage (SMES) device with a PWM voltage source converter and a DC-DC chopper is proposed to enhance the DFIG LVRT and HVRT capabilities in an islanded microgrid simultaneously. The simulation results demonstrate that the SMES absorbs or releases energy from/to the microgrid during voltage swell events and fault condition respectively and consequently, improves the DFIG performance and enhances the DFIG LVRT and HVRT capabilities. The effectiveness of the proposed method is validated through detailed simulations in PSCAD/EMTDC
The anticoccidial effect of alcoholic extract of Citrullus colocynthis fruit and Juglans regia peel‌ in experimentally infected domestic chicken
One of the main illnesses within the poultry industry is coccidiosis. Anticoccidial medicines applied in the poultry industry show many shortcomings and new control measures are necessary. The current research aimed to study the effect of extract of Citrullus colocynthis and Juglans regia peel on growth performance, gut bacteria, Haematological, Anticoccidial Index (ACI), and Optimum Anticoccidial Activity (OAA) of coccidiosis-infected domestic chicken. The maximum weight gain was observed in the groups treated with 0.001% and 0.01% C. colocynthis extract. Moreover, 0.01% C. colocynthis extract treatment increased two factors of ACI and OAA by 121.42 and 109, respectively, which were higher than commercial anticoccidial (Sulfaclozine). The extract of C. colocynthis fruit and J. regia peel decreased monocytes and eosinophils haematological factors and increased basophils in birds infected with Eimeria. Both extracts modulated intestinal microbiome haematological factors in birds infected with Eimeria, while J. regia peel extract had better performance than C. colocynthis fruit extract. These results indicate that used C. colocynthis and J. regia extracts have an anti-coccidial effect and the potential to control Eimeria infection. © 2023 Elsevier Lt
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