99 research outputs found
Chemical Composition and Antioxidant Activity of Heracleum sprengelianum (Wight and Arnott) Essential Oils Growing Wild in Peninsular India
No full textAbstract The essential oils, isolated by hydrodistillation from the leaves, seeds and rhizomes of Heracleum sprengelianum (Wight and Arnott), collected from the Western Ghats of Peninsula India, were analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS). The antioxidant property of these oils was tested, with and without peroxidation inducer, through the egg yolk-based Thiobarbituric Acid Reactive Substances assay (TBARS assay) and in the concentrations of 50, 100, 250 and 500 mg/L. β-Pinene, 1,8-Cineole, β-Phellandrene and ρ-Cymen-8-ol were the main components of H. sprengelianum leaves, seeds and rhizomes essential oils. The oils demonstrated the antioxidant capacity in the absence of radical inducer 2, 20-azobis-(2-amidinopropane) dihydrochloride (ABAP), mainly that of H. sprengelianum at 250 and 500 mg/L, comparable in some cases to that of α-tocopherol and butylated hydroxytoluene (BHT). The presence of ABAP diminished the antioxidant ability of all tested essential oils, leaf oils of H. sprengelianum still showing the highest antioxidant capacity at 500 mg/L. At 250 and 500 mg/L for BHA, and 500 mg/L for α-tocopherol, the antioxidant capacity significantly increased in the presence of ABAP
Author Correction: COVID-19 vaccine guidance for patients with cancer participating in oncology clinical trials
No full textIn the original version of this Perspective, the name of the author Giuseppe Curigliano was incorrectly written as Guiseppe Curigiliano. The affiliations have been corrected in the HTML and PDF versions of the manuscrip
Author Correction: EGFR and HER2 exon 20 insertions in solid tumours: from biology to treatment (Nature Reviews Clinical Oncology, (2022), 19, 1, (51-69), 10.1038/s41571-021-00558-1)
No full textNovel Simulator for Wireline Mini-Fracture Testing
No full textWireline Mini-Fracture testing jobs consist of a short duration, small volume fracturing operation inside an open-hole borehole, where a certain amount of fluid is injected into the formation at constant rate using a Wireline Modular conveyed tool as a source of hydraulic power to pressurize the wellbore. The tool is configured with an inflatable straddle packer and an internal pump, which inflate/deflates the packers and supplies pressure to the formation until a hydraulic fracture is induced. This procedure is used to determine in–situ formation breakdown and closure pressure also known as minimum horizontal closure pressure. This provides vital information regarding hydraulic fracture design, water and gas injection management, fault re-activation, wellbore stability, sand production, rock mechanical properties, casing string design, cap and base rock integrity and gas storage design. Geomechanical and operational parameters such as, elastic properties, poro-elasticity, rock strength, formation pore pressure, far field horizontal stress, permeability/porosity distributions, borehole fluid properties among others, influences the performance of the Mini-Frac Jobs. In many cases poor understanding of the reservoir response to the fracture process, caused that the hydraulic fracture did not propagate deep into the formation. In other cases the pressure applied to the formation might be insufficient to break down the formation, leading to unsatisfactory application of the Mini-Fracture technique in the process. The objective of this thesis is to develop a Mini-Facture application simulator that uses the geomechanical and operational parameters that control the performance of a Mini-Fracture job and estimate the possibility of the occurrence of a tensile failure in the formation. The simulator is then validated by comparing its output with the results of stress test done in the field. With this simulator petrotechnical professionals and field engineers will have a platform that simulates the pressure responses and fracture initialization during Mini-Frac treatments, incorporating all the variables affecting a Wireline Mini-Fracture job, helping the design engineer to make key decisions about the ultimate or required fracture plan. Furthermore the simulator will reduce the uncertainties that limit the reliability of the Wireline Mini-Fracture treatment by allowing the selection of appropriate tool configuration based on the job objectives and the geological environmental conditions. Finally this project demonstrates that combining the appropriate constitutive relations that reflect the coupling among the tool operational performance with wellbore flow, reservoir and geomechanics modelling a Mini-Fracture simulator can be developed.Petroleum EngineeringGeoscience & EngineeringCivil Engineering and Geoscience
Information Technology: Equalizer or Separator of Developing Countries?
No full textThe author discusses about the Information technology scenario in developing countries
China promotes traditional medicine
No full textThe author reports the promotional activities undertaken by China in the field of traditional medicine
Is mathematics research in India on the decline?
No full textIn this paper the author analyses the research dynamics of Mathematics research in India using the multidisciplinary database Science Citation Index®
Recommended from our members
Correspondence on "Diabetes Research in India"
No full textThis is a correspondence generated by the article "Diabetes research in India" between the author, A. Subiah Arunachalam and Rosalind Marita
Machining of brittle materials using precision crack-off
No full textAt present, a high wasteful and time-consuming method is widely used in silicon fabrication industry for slicing silicon wafers. To minimize the cost as well as shorten lead time, a new fabrication method should be brought out.
The objective of this project is to verify and develop precision crack-off method which can be used for breaking and slicing silicon ingot even all brittle materials.
In this report, the author described preparations and procedures of the experiments, such as 3-point bending test, and precision crack-off method on rods with 1 and 2 notches respectively. Based on the experimental result, the author analyzed parameters that affect the surface finish of cracking surface and proposed improved ideas for further experiments. In addition, due to failure of some experiments, the author also gave possible explanations. Furthermore, since the main purpose of this project is to apply a new method to mass production, the author provided a feasible experimental setup to be examined further. Last but not least, the author discussed whether this method can be applied to crystalline materials.Bachelor of Engineering (Mechanical Engineering
- …
