Abstract Effectively managing resources encompasses accurate engineering of target formations and prudent execution of project capital. Attaining both requires employing current technologies and implementing efficient operations, especially with today's challenging drilling environment and economic climate. The influence of improved technologies and the latest operational developments has lead to a significant impact in the arena of coiled-tubing drilling operations. Coiled-tubing drilling is a rapidly growing technology that has been used for various applications nowadays such as drilling shallow new wells, re-entry applications, sidetracking etc. This paper summarizes the hypotheses and theories relating to the causes and expectations of Coiled-tubing drilling in various reservoirs worldwide. The intent of the paper is to:Provide a concise compendium to the current understanding of the coiled-tubing drilling operations.Provide a comprehensive single-source review of the various projects successfully completed in the area and lessons learned.Help operators develop operational and design strategies for current and future projects, as well as to input parameters for simulating current and future projects.
Abstract In this work, wood apple leaves dye has been extracted, characterized, and examined as a potential photosensitizer for dye-sensitized solar cells (DSSCs). The dye was extracted in an ethanolic medium from the fresh wood apple leaves and characterized using thin-layer chromatography (TLC), ultraviolet-visible (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy. The current density-voltage (J–V) characteristics measurements were performed on the two assembled DSSCs for 1–22 days using fresh and seven days old extracted dye. The characterization results revealed that the extracted dye mainly contains the compound of carotenoids (neoxanthin), chlorophyll a, chlorophyll b, and their derivative (pheophytin) with various functional groups. The J–V characteristics of DSSCs indicate that an open-circuit voltage and short circuit current density radically decrease with increasing time, thus degrading the efficiency of cells. A degraded DSSCs suffered from high defect recombination may be induced by Mg ions migrating from chlorophyll dye into DSSC. Therefore, the extracted dye may be used for energy harvesting from the wood apple leaves.
Objective: To deposit the highly crystalline thin film of vanadium pentoxide on Si substrate. Method: In this work, we deposited vanadium oxide thin films by RF sputtering setup. These deposited thin films were annealed at 500°C for 1 hour in argon atmosphere. Grazing Incidence X-Ray Diffraction (GIXRD), Raman Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR) are used to analyze structural properties of as-deposited and annealed thin films of vanadium oxide. Finding: GIXRD spectra of annealed film revealed that highly crystalline thin film of vanadium pentoxide (V2 O5 ) is obtained. The texture of the film is oriented along c- axis, perpendicular to the surface of the Si substrate and it’s a, b axis are parallel to the surface of substrate. Raman Spectroscopy and FTIR results confirmed the layered structure of the annealed vanadium pentoxide thin film. After post annealing, the highly crystalline and layered structure of V2 O5 thin film on Si substrate is obtained. Applications: Vanadium pentoxide thin films are used in electrochromic devices, lithium batteries, and energy storage devices and as toxic gas sensors. Keywords: Vanadium Pentoxide (V2 O5 ), Grazing Incidence X-Ray Diffraction (GIXRD), Raman Spectroscopy, RF Sputtering
The present study is carried out for the investigation of energetic ion beam mixing in the Bi/Ge system, induced by electronic excitation. The system Ge/Bi/C was deposited on Si substrate at room temperature in the high vacuum deposition system and irradiated using Au ions of 120 MeV at the fluences 1 × 1013, 5 × 1013 and 1 × 1014 ions/cm2. The top layer of carbon was deposited as the protecting layer to avoid oxidation. The swift heavy ions (SHI)-induced interface mixing was studied by Rutherford backscattering spectroscopy (RBS) for depth profiles and compositions, grazing incidence X-ray diffraction (GIXRD) for phase identification and atomic force microscopy (AFM) for surface roughness. We have calculated the mixing rate, mixing efficiency and inter-diffusion coefficient for the Bi/Ge system. We observed that the thickness of the mixed region increased with increasing fluence. In the GIXRD pattern, no new crystalline phase formation was observed after irradiation, the mixed region may be in an amorphous form. The mixing effect is explained in the framework of the thermal spike model.
Abstract In this work, we report the study of swift heavy ion-induced mixing at the interface of an a-Si/Nb/ a-Si (a-Si=amorphous silicon) thin film system at different fluences using two different characterization techniques: secondary ion mass spectroscopy and Rutherford backscattering spectrometry. The depth profiles of the samples of this system showed significant changes in the interface region when irradiated by 120 MeV Au ions. The fluence range was varied from 1×1013 to 1×1014 ions/cm2. Significant interface mixing has been observed in this range and was found to increase linearly with the increase in the ion fluence. Atomic force microscopy of the samples was also performed to confirm that there is no significant contribution of surface roughness. Mixing has been quantified in terms of mixing rate (k). This high energy-induced mixing effect has been explained in the framework of the thermal spike model which verifies the hypothesis of melt-phase diffusion across the interface. Keywords: ion beam mixingswift heavy ionselectronic energy loss Acknowledgements Dr Diva is grateful to the Metallurgy Division, TBRL (DRDO), Chandigarh, for facilitating the completion this work. Dr R.S. Chauhan would like to thank UGC, New Delhi, for the financial support in terms of a project. We are thankful to Dr Pivin (Orsay Campus, France) and Dr D.K. Avasthi of IUAC, Delhi, for their help and suggestions and Ms Neeti Tripathi (Delhi University) for the AFM data.
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