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[IEEE 2018 IEEE 7th International Conference on Photonics (ICP) - Langkawi, Malaysia (2018.4.9-2018.4.11)] 2018 IEEE 7th International Conference on Photonics (ICP) - Detection of Power Transformer Fault Conditions using Optical Characteristics of Transformer Oil
摘要： Power transformers are important in the power transmission and distribution network. A continuous monitoring of the transformer is important in ensuring the prolonged service of the transformer. This paper focuses on the characterization of transformer oil using optical detection method. 10 Transformer oil samples from the main tanks and 11 oil samples from the on-load-tap-changer (OLTC) were obtained for the optical characterization from 200 to 3300 nm. Based on the conventional results interpretation using dissolved gas analysis (DGA) and Duval Triangle, the optical characteristics of the samples in 2120 to 2220 nm clearly demonstrate the detection of electrical discharges of high energy (D2), electrical discharges of low energy (D1) and thermal faults at temperatures above 700°C (T3) faults. This approach provides a quicker and cheaper method to determine the condition of power transformers based on the optical characteristics of transformer oil.
关键词： spectrophotometer,On-load-tap-changer,main transformer tank,transformer oil aging
更新于2025-09-10 09:29:36
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Spectrophotometric Study of the Effect of Luting Agents on the Resultant Shade of Ceramic Veneers: An Invitro Study
摘要： Introduction: Dentistry has found practically the best available aesthetic answer, is ceramic restoration. There are various factors that contribute to the success of ceramic veneers, like colour of underlying tooth, thickness if ceramics and the type of underlying luting cement. Shade selection and matching remains still challenge, however the shade of luting agent used for cementation of veneers produces a change in resultant shade of veneers. Aim: To compare and analyze the spectrophotometric effect of opaque and transparent luting agent on resultant shade of ceramic veneers made of 2L1.5 shade (Vitapan 3D-Masters) and B2 shade (Vitapan Classic). Materials and Methods: Out of 15 ceramic veneers of 2L1.5 shade (VITAPAN 3D- Master), seven teeth cemented with opaque cement and eight teeth with transparent cement shade of dual cure resin cement (Variolink IITM). Out of 10 ceramic veneers of B2 shade (VITAPAN Classic), five teeth were cemented with opaque cement and other five teeth with transparent cement shade of dual cure resin cement (Variolink IITM). Spectrophotometric (Macbeth U.S.A.) analysis of all ceramic veneer crowns done with optiview software and readings were recorded in Commission Internationale de I’ Eclairge {CIELAB} system and dE value was calculated. Statistical Analysis: Statistical analysis was done by using Paired t-test. results: Spectrophotometric analysis of all the veneers cemented with opaque luting agent were lighter in shade due to significant change in dL value. Veneers cemented with transparent luting agent were darker in shade due to significant change in the dL value. conclusion: Opaque luting agent gives lighter shade and transparent luting agent gives darker shade to ceramic veneers fabricated with 2L1.5 and B2 shades.
关键词： Spectrophotometer,Aesthetic dentistry,Discolouration,Restoration
更新于2025-09-10 09:29:36
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Determination of complex refractive index of SU-8 by Kramers-Kronig dispersion relation method at the wavelength range 2.5 – 22.0 μm
摘要： Accurate determination of the complex refractive index of SU-8 epoxy has significant for the wide variety of applications in optical sensor technology at IR range. The complex refractive index of SU-8 is determined by recording the transmission of light spectra for the wavelength range of 2.5 – 22.0 μm. The data analysis is based on the Kramers-Kronig dispersion relation method. The method has several merits, such as ease of operation, non-contact technique, measurement accuracy, and rapid measurement. The present method is not restricted to the case of SU-8 but it is also proposed to be applicable across a broad range of applications, such as assessment of the optical properties of paints and biomedical samples.
关键词： SU-8 epoxy,FT-IR spectrophotometer,Infrared region,Kramers-Kronig dispersion relation method,Complex refractive index
更新于2025-09-10 09:29:36
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Aerosol optical depth in the European Brewer Network
摘要： The high spatial and temporal variability of aerosols makes networks capable of measuring their properties in near real time of high scientific interest. In this work we present and discuss results of an aerosol optical depth algorithm to be used in the European Brewer Network, which provides data in near real time of more than 30 spectrophotometers located from Tamanrasset (Algeria) to Kangerlussuaq (Greenland). Using data from the Brewer Intercomparison Campaigns in the years 2013 and 2015, and the period in between, plus comparisons with Cimel sunphotometers and UVPFR instruments, we check the precision, stability, and uncertainty of the Brewer AOD in the ultraviolet range from 300 to 320 nm. Our results show a precision better than 0.01, an uncertainty of less than 0.05, and a stability similar to that of the ozone measurements for well-maintained instruments. We also discuss future improvements to our algorithm with respect to the input data, their processing, and the characterization of the Brewer instruments for the measurement of aerosols.
关键词： European Brewer Network,uncertainty,ultraviolet range,precision,aerosol optical depth,stability,Brewer spectrophotometer
更新于2025-09-09 09:28:46
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Investigation on Physical Properties of Semiorganic Nonlinear Optical Glycine Zinc Sulfate Single Crystal
摘要： Nonlinear optical single crystals of Glycine Zinc Sulfate (GZS) were grown by slow evaporation technique. Single crystal X-ray diffraction analysis revealed the crystal system and lattice parameter values. Powder X-ray diffraction analyses have been carried out and the diffraction patterns have been indexed. The optical properties of the crystals were determined using UV-Visible spectroscopy. Optical constants such as band gap, refractive index, extinction coefficient and electric susceptibility were determined from UV-Visible spectroscopy. The refractive index was determined using Brewster’s angle method. Hardness of the GZS crystal was estimated by Vicker’s hardness studies. Second Harmonic Generation (SHG) of GZS crystal was investigated by Kurtz powder technique. The dielectric constant and dielectric loss measurements were carried out for different temperatures and frequencies. The photoconductivity studies confirm that the grown crystal has negative photoconductivity nature. In order to investigate the growth mechanism and surface features, etching studies are carried out for the crystal.
关键词： NLO,single X-ray diffraction,SHG,UV-Vis-NIR spectrophotometer,dielectric loss studies,dielectric constant
更新于2025-09-09 09:28:46
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DEVELOPMENT AND VALIDATION OF UV-SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF HYDROQUINONE IN BULK, MARKETED CREAM AND PREAPARED NLC FORMULATION
摘要： The aim of the present work was to develop a simple, rapid, accurate and economical UV-visible spectrophotometric method for the determination of hydroquinone (HQ) in its pure form, marketed formulation as well as in the prepared nanostructured lipid carrier (NLC) systems and to validate the developed method. HQ was estimated at UV maxima of 289.6 nm in pH 5.5 phosphate buffer using UV-Visible double beam spectrophotometer. Following the guidelines of the International Conference on Harmonization (ICH), the method was validated for various analytical parameters like linearity, precision, and accuracy robustness, ruggedness, limit of detection, quantification limit, and formulation analysis. The obtained results of the analysis were validated statistically. Recovery studies were performed to confirm the accuracy of the proposed method. In the developed method, linearity over the concentration range of 5-40 μg/ml of HQ was observed with the correlation coefficient of 0.998 and found in good agreement with Beer Lambert’s law. The precision (intra-day and inter-day) of the method was found within official RCD limits (RSD<2%). The sensitivity of the method was assessed by determining the limit of detection and limit of quantification. It could be concluded from the results obtained that the purposed method for estimation of HQ in pure form, in the marketed ointment and in the prepared NLC-formulation was simple, rapid, accurate, precise and economical. It can be used successfully in the quality control of pharmaceutical formulations and for the routine laboratory analysis.
关键词： Nanostructured lipid carriers,UV Spectrophotometer,Validation,Hydroquinone
更新于2025-09-09 09:28:46
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Evaluation of the Level of Transmission of Solar Radiation by Eyeglasses (Spectacles) and its Effects on the Human Eye
摘要： Global atmospheric changes such as depletion of Ozone in the stratosphere and global warming contribute to the average increase of ultraviolet radiation on earth. Protective eyeglasses are normally recommended to safeguard the eyes from the harmful effects of solar radiation. In this paper, twenty (20) pairs of eyeglasses were selected based on systematic random sampling to determine the amount of optical radiation transmission and level of attenuation by eyeglasses, in the wavelength range of 200nm to 900nm using 6405 UV/VIS spectrophotometer. All the eyeglasses were found to transmit a substantial amount of ultraviolet radiation. The transmission of visible light depends on the lens colours. It was discovered that the eyeglasses do not provide complete protection from UV radiation. This shows that the glasses can still pose great danger to human eyes.
关键词： Spectrophotometer,Eyeglasses,Human eye,Percentage transmittance (%T),Optical radiation,Global warming,Depletion of Ozone,Solar radiation,Attenuation
更新于2025-09-04 15:30:14
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Forensic Discrimination Potential of Video Spectral Comparator and Micro Spectrophotometer in Analyzing Question Document and Fraud Cases in India
摘要： The aim of the study was to evaluate the discriminating power of non-destructive methods, including optical methods likes the Video spectral comparator method (VSC) and Micro spectrophotometer (MSP) used to differentiate ballpoint pen ink which is commonly used in question document and fraud cases in India. Documents have been investigated to determine the feasibility of utilizing the Video spectral comparator method (VSC) and Micro spectrophotometer (MSP) for the differentiation and comparison of inks on paper. The work focused on how to develop the most effective procedure to ensure quality, when Micro spectrophotometer is used to differentiate writing materials by characteristics color scan of each ink. Six different commercially available blue ballpoint pen inks produced from most popular pens in Indian Market which were used as research material. We have studied most selling pens in Indian market (Reynolds, Parker, and Lexis 2 types, Cello griper and local made pen) for overwriting, alternation and modification of ballpoint pen ink on documents. These pens are generally used on questioned document in forensic discrimination cases and these questioned documents cases received by forensic science laboratories regularly. In forensic discrimination cases generally initial writing is overwritten by using other ink and to identify which ink was used to overwrite is challenging task in field of forensic science. The present study highlighted that the Video Spectral Comparator method (VSC) and Micro spectrophotometer (MSP) can be used routinely in such types of document cases and it has demonstrated to be an excellent analytical method for the forensic analysis of inks on a questioned document.
关键词： Overwriting of inks,Question document,Video spectral comparator,Micro spectrophotometer
更新于2025-09-04 15:30:14
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Retrieval of aerosol optical depth in the visible range with a Brewer spectrophotometer in Athens
摘要： A MkIV Brewer spectrophotometer has been operating in Athens since 2004. Direct-sun measurements originally scheduled for nitrogen dioxide retrievals were reprocessed to provide aerosol optical depths (AODs) at a wavelength of about 440 nm. A novel retrieval algorithm was specifically developed and the resulting AODs were compared to those obtained from a collocated Cimel filter radiometer belonging to the Aerosol Robotic Network (AERONET). The series are perfectly correlated, with Pearson’s correlation coefficients being as large as 0.996 and with 90 % of AOD deviations between the two instruments being within the World Meteorological Organisation (WMO) traceability limits. In order to reach such a high agreement, several instrumental factors impacting the quality of the Brewer retrievals must be taken into account, including sensitivity to the internal temperature, and the state of the external optics and pointing accuracy must be carefully checked. Furthermore, the long-term radiometric stability of the Brewer was investigated and the performances of in situ Langley extrapolations as a way to track the absolute calibration of the Brewer were assessed. Other sources of error, such as slight shifts of the wavelength scale, are discussed and some recommendations to Brewer operators are drawn. Although MkIV Brewers are rarely employed to retrieve AODs in the visible range, they represent a key source of information about aerosol changes in the past three decades and a potential worldwide network for present and future coordinated AOD measurements. Moreover, a better understanding of the AOD retrieval at visible wavelengths will also contribute in improving similar techniques in the more challenging UV range.
关键词： Cimel sun-sky photometer,AERONET,aerosol optical depth,Athens,Brewer spectrophotometer
更新于2025-09-04 15:30:14
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Preparation of ZnO Nanoparticles Under Ultrasonic Irradiation and Photocatalytic Performance of ZnO Nanoparticles Multilayer Films
摘要： Zinc oxide nanoparticles were synthesized by the reaction of an aqueous-alcoholic solution containing zinc nitrate hexahydrate and sodium hydroxide under ultrasonic irradiation at room temperature. The crystallinity, morphology and optical property of ZnO nanoparticles were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-visible spectrophotometer. Zinc oxide nanoparticles multilayer films were prepared dipping glass slide, which had been cleaned with a piranha solution, into a ZnO solution by ultrasonic irradiation. The ZnO nanoparticles multilayer films were evaluated as a photocatalyst in the photocatalytic degradation of organic dyes, such as methylene blue, methyl orange and rhodamine B, under ultraviolet light at 254 nm.
关键词： Multilayer films,Photocatalytic activity,Zinc oxide nanoparticles,Organic dyes,UV-visible spectrophotometer
更新于2025-09-04 15:30:14