GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Hindawi Limited  (6)
  • 1
    Online Resource
    Online Resource
    Modeling Friction Performance of Drill String Torsional Oscillation Using Dynamic Friction Model
    Hindawi Limited ; 2017
    In:  Shock and Vibration Vol. 2017 ( 2017), p. 1-14
    Details
    In: Shock and Vibration, Hindawi Limited, Vol. 2017 ( 2017), p. 1-14
    Abstract: Drill string torsional and longitudinal oscillation can significantly reduce axial drag in horizontal drilling. An improved theoretical model for the analysis of the frictional force was proposed based on microscopic contact deformation theory and a bristle model. The established model, an improved dynamic friction model established for drill strings in a wellbore, was used to determine the relationship of friction force changes and the drill string torsional vibration. The model results were in good agreement with the experimental data, verifying the accuracy of the established model. The analysis of the influence of drilling mud properties indicated that there is an approximately linear relationship between the axial friction force and dynamic shear and viscosity. The influence of drill string torsional oscillation on the axial friction force is discussed. The results indicated that the drill string transverse velocity is a prerequisite for reducing axial friction. In addition, low amplitude of torsional vibration speed can significantly reduce axial friction. Then, increasing the amplitude of transverse vibration speed, the effect of axial reduction is not significant. In addition, by involving general field drilling parameters, this model can accurately describe the friction behavior and quantitatively predict the frictional resistance in horizontal drilling.
    Type of Medium: Online Resource
    ISSN: 1070-9622 , 1875-9203
    URL: Article
    DOI: 10.1155/2017/4051541
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2017
    detail.hit.zdb_id: 2070162-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Experimental Investigation on Proppant Transport Behavior in Hydraulic Fractures of Tight Oil and Gas Reservoir
    Hindawi Limited ; 2022
    In:  Geofluids Vol. 2022 ( 2022-3-24), p. 1-14
    Details
    In: Geofluids, Hindawi Limited, Vol. 2022 ( 2022-3-24), p. 1-14
    Abstract: Proppant concentration and fracture surface morphology are two significant fractures that can affect proppant transport and deposition behavior especially in tight and oil and gas reservoirs. This paper proposed a new set of similarity criteria for proppant experimental design by incorporating proppant concentration and fracture roughness. Based on the proposed criterion, proppant transport experiments in hydraulic fractures of tight oil and gas reservoirs were conducted to explore the proppant placement behavior and identify the key parameters that affected the fracture propping efficiency. Results showed that the proposed similarity criterion can be used to evaluate the onsite proppant transport behavior and optimize hydraulic fracturing parameters. Results showed that the fracture placement efficiency of LD C7 tight oil reservoir is mainly affected by sand ratio and fracturing fluid viscosity. The sand ratio in the LD C7 tight oil reservoir should not be less than 8%, and the optimal carrying fluid viscosity is 5 mPa s. The proppant placement efficiency of the SLG H8 tight gas reservoir is mainly affected by the displacement rate and frac fluid viscosity. The displacement rate of SLG H8 tight gas reservoir should not be less than 3.5 m3/min, and the optimal carrying fluid viscosity is 15 mPa s.
    Type of Medium: Online Resource
    ISSN: 1468-8123 , 1468-8115
    URL: Article
    DOI: 10.1155/2022/1385922
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2045012-6
    SSG: 13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Follistatin-Like 1: A Potential Mediator of Inflammation in Obesity
    Hindawi Limited ; 2013
    In:  Mediators of Inflammation Vol. 2013 ( 2013), p. 1-12
    Details
    In: Mediators of Inflammation, Hindawi Limited, Vol. 2013 ( 2013), p. 1-12
    Abstract: Obesity is associated with a state of chronic low-grade inflammation, which contributes to insulin resistance and type 2 diabetes. However, the molecular mechanisms that link obesity to inflammation are not fully understood. Follistatin-like 1 (FSTL1) is a novel proinflammatory cytokine that is expressed in adipose tissue and secreted by preadipocytes/adipocytes. We aimed to test whether FSTL1 could have a role in obesity-induced inflammation and insulin resistance. It was found that FSTL1 expression was markedly decreased during differentiation of 3T3-L1 preadipocytes but reinduced by TNF- α . Furthermore, a significant increase in FSTL1 levels was observed in adipose tissue of obese ob/ob mice, as well as in serum of overweight/obese subjects. Mechanistic studies revealed that FSTL1 induced inflammatory responses in both 3T3-L1 adipocytes and RAW264.7 macrophages. The expression of proinflammatory mediators including IL-6, TNF- α , and MCP-1 was upregulated by recombinant FSTL1 in a dose-dependent manner, paralleled with activation of the IKK β -NF κ B and JNK signaling pathways in the two cell lines. Moreover, FSTL1 impaired insulin signaling in 3T3-L1 adipocytes, as revealed by attenuated phosphorylation of both Akt and IRS-1 in response to insulin stimulation. Together, our results suggest that FSTL1 is a potential mediator of inflammation and insulin resistance in obesity.
    Type of Medium: Online Resource
    ISSN: 0962-9351 , 1466-1861
    URL: Article
    DOI: 10.1155/2013/752519
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2013
    detail.hit.zdb_id: 2008065-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Investigation of Statin Medication Use in Elderly Patients with Cardiovascular Disease on Regular Physical Examination and the Relationship with Glucolipid Metabolism and Adverse Cardiovascular Prognosis
    Hindawi Limited ; 2022
    In:  Disease Markers Vol. 2022 ( 2022-6-16), p. 1-5
    Details
    In: Disease Markers, Hindawi Limited, Vol. 2022 ( 2022-6-16), p. 1-5
    Abstract: Our purpose of this study was to investigate the use of statins in elderly patients with cardiovascular diseases during regular physical examination and to analyze the relationship between statins and glucose and lipid metabolism and adverse cardiovascular prognosis. From January 2019 to December 2021, 2121 elderly patients with cardiovascular disease underwent regular physical examination as the study subjects to investigate the use and intensity of statins. The patients were divided into the dosing group ( n = 1848 ) and the nondosing group ( n = 273 ) according to whether they were taking statins or not. The cardiac function, glucose and lipid metabolism indexes, and cardiovascular adverse events were compared between the two groups. Statin use in elderly patients with cardiovascular disease was 87.13% (1848/2121). The intensity of statin use decreased with age ( P 〈 0.05 ); the left ventricular ejection fraction (LVEF) was greater in the medicated group than in the nonmedicated group, and the left ventricular end-diastolic internal diameter (LVDd) and left ventricular end-systolic internal diameter (LVDs) were smaller than in the nonmedicated group ( P 〈 0.05 ). The total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose (FBG) levels were lower in the medicated group than in the nonmedicated group, the high-density lipoprotein cholesterol (HDL-C) levels were higher than in the nonmedicated group, and the glycated hemoglobin (HbA1c) values were lower than in the nonmedicated group ( P 〈 0.05 ). The overall incidence of cardiovascular adverse events in the medicated group was lower than that in the nonmedicated group ( P 〈 0.05 ). Statin use was higher in elderly patients with cardiovascular disease; the intensity of drug use decreased with age. The patients’ cardiac function, glucose metabolism, and prognosis were significantly improved after statin treatment.
    Type of Medium: Online Resource
    ISSN: 1875-8630 , 0278-0240
    URL: Article
    DOI: 10.1155/2022/8714392
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2033253-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Sperm cryopreservation of the noble Scallop Chlamys nobilis by a programmable freezing method: Effect of cryoprotectant
    Hindawi Limited ; 2019
    In:  Aquaculture Research Vol. 50, No. 6 ( 2019-06), p. 1678-1686
    Details
    In: Aquaculture Research, Hindawi Limited, Vol. 50, No. 6 ( 2019-06), p. 1678-1686
    Type of Medium: Online Resource
    ISSN: 1355-557X , 1365-2109
    URL: Issue
    URL: Article
    DOI: 10.1111/are.2019.50.issue-6
    DOI: 10.1111/are.14050
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2019
    detail.hit.zdb_id: 2207423-5
    detail.hit.zdb_id: 1227359-4
    detail.hit.zdb_id: 2019895-4
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Polydatin Alleviates Small Intestine Injury during Hemorrhagic Shock as a SIRT1 Activator
    Hindawi Limited ; 2015
    In:  Oxidative Medicine and Cellular Longevity Vol. 2015 ( 2015), p. 1-12
    Details
    In: Oxidative Medicine and Cellular Longevity, Hindawi Limited, Vol. 2015 ( 2015), p. 1-12
    Abstract: Objective . To evaluate the role of SIRT1 in small intestine damage following severe hemorrhagic shock and to investigate whether polydatin (PD) can activate SIRT1 in shock treatment. Research Design and Methods . The severe hemorrhagic shock model was reproduced in Sprague Dawley rats. Main Outcome Measures . Two hours after drug administration, half of the rats were assessed for survival time evaluation and the remainder were used for small intestinal tissue sample collection. Results . Bleeding and swelling appeared in the small intestine with epithelial apoptosis and gut barrier disturbance during hemorrhagic shock. SIRT1 activity and PGC-1 α protein expression of the small intestine were decreased, which led to an increase in acetylated SOD2 and decreases in the expression and activity of SOD2, resulting in severe oxidative stress. The decreased SIRT1 activity and expression were partially restored in the PD administration group, which showed reduced intestine injury and longer survival time. Notably, the effect of PD was abolished after the addition of Ex527, a selective inhibitor of SIRT1. Conclusions . The results collectively suggest a role for the SIRT1-PGC-1 α -SOD2 axis in small intestine injury following severe hemorrhagic shock and that PD is an effective SIRT1 activator for the shock treatment.
    Type of Medium: Online Resource
    ISSN: 1942-0900 , 1942-0994
    URL: Article
    DOI: 10.1155/2015/965961
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2015
    detail.hit.zdb_id: 2455981-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...