Vacuum-ultraviolet circular dichroism spectrophotometer using synchrotron radiation

International Nuclear Information System (INIS)

Matsu, K.; Yonehara, R.; Gekko, K.

2004-01-01

Full text: Circular dichroism (CD) spectroscopy is powerful for analyzing the structure of optically active materials such as biopolymers. However, no commercial CD spectrophotometer is capable of measuring the CD in the vacuum ultraviolet (VUV) region below 190 nm because of technical difficulties involved in the light source, optical device, and sample cell. CD measurements extended to the VUV region can provide more detailed and new information on the structure of biopolymers based on the higher energy transition of chromophores such as hydroxyl and acetal groups. We have constructed a VUVCD spectrophotometer to measure the CD spectra of biomaterials in aqueous solutions in the 310-140 nm wavelength region under a high vacuum, using a small-scale SR source (0.7 GeV) at Hiroshima Synchrotron Radiation Center (HiSOR). All optical devices of the spectrophotometer were set up under a high vacuum (10 -6 Torr), to avoid the absorption of light by air and water vapor. The SR light is separated into two orthogonal linearly polarized light beams by a linear polarizer and then modulated to circularly polarized light at 50 kHz by a photo-elastic modulator (PEM). In order to control PEM accurately and to stabilize the lock-in amplifier under a high vacuum, we used the optical servo-control system. Also, an assembled-type MgF 2 cell with a temperature-control unit was constructed using a Peltier thermoelectric element. Its path length can be adjusted by various Tefron spacers in the range from 1.3 to 50 μm and its temperature can be controlled within an accuracy of ± 1 deg C in the range from -30 to 70 deg C. The performance of the spectrophotometer and MgF 2 cell constructed was tested by monitoring the CD spectra of ammonium d-camphor-10-sulfonate (ACS), D- and L-isomers of amino acids. These obtained results demonstrate that the optical system and the sample cell constructed normally operate under a high vacuum to provide useful information on the structure analysis of

Vacuum-ultraviolet circular dichroism spectrophotometer using synchrotron radiation

International Nuclear Information System (INIS)

Matsuo, K.; Fukuyama, T.; Yonehara, R.; Namatame, H.; Taniguchi, M.; Gekko, K.

2005-01-01

We have constructed a vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer using a synchrotron radiation and an assembled-type MgF 2 cell endurable under a high vacuum, to measure the CD spectra of biomaterials in aqueous solutions from 310 to 140 nm. To avoid the absorption of light by air and water vapor, all optical devices of the spectrophotometer were set up under a high vacuum (10 -4 Pa). A path length of the optical cell can be adjusted by various Teflon spacers in the range from 1.3 to 50 μm and its temperature can be controlled to an accuracy of ±1 deg. C over the range from -30 to 70 deg. C by a temperature-control unit using a Peltier thermoelectric element. The performance of the spectrophotometer and the optical cell constructed was tested by measuring the CD spectra of ammonium d-camphor-10-sulfonate, D- and L-isomers of amino acids, and myoglobin in aqueous solutions. The spectra obtained demonstrate that the optical system and the sample cell constructed operate normally under a high vacuum and provide useful information on the structure of biomolecules based on the higher energy chromophores

The Fuge Tube Diode Array Spectrophotometer

Science.gov (United States)

Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.

2008-01-01

We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

Modernization of Atomic Absorption Spectrophotometer

International Nuclear Information System (INIS)

Tasic, Visa; Milivojevic, Dragan; Karabasevic, Dejan

2003-01-01

In Copper Institute in Bor, connection has been made between absorption spectrophotometer and standard PC with the aim to make its operation more reliable and comfortable. Applied solution includes both software and hardware components. An I/O interface module has been installed in PC [1]. Software component consists of programs for measuring and interpretation of results. Paper presents details of this job realization.(Author)

Automated dual-wavelength spectrophotometer optimized for phytochrome assay

International Nuclear Information System (INIS)

Pratt, L.H.; Wampler, J.E.; Rich, E.S. Jr.

1985-01-01

A microcomputer-controlled dual-wavelength spectrophotometer suitable for automated phytochrome assay is described. The optomechanical unit provides for sequential irradiation of the sample by the two measuring wavelengths with intervening dark intervals and for actinic irradiation to interconvert phytochrome between its two forms. Photomultiplier current is amplified, converted to a digital value and transferred into the computer using a custom-designed IEEE-488 bus interface. The microcomputer calculates mathematically both absorbance and absorbance difference values with dynamic correction for photomultiplier dark current. In addition, the computer controls the operating parameters of the spectrophotometer via a separate interface. These parameters include control of the durations of measuring and actinic irradiation intervals and their sequence. 14 references, 4 figures

Satellite spectrophotometer for research of the atmospheric ozone

International Nuclear Information System (INIS)

Getzov, P.; Mardirossian, G.; Stoyanov, S.

2014-01-01

The measurement of atmospheric ozone and its influence upon climate and life on Earth is undoubtedly one of the most pressing issues of present time. A mathematical model of an optical tract of a spectrophotometer has been designed. The paper presents the functional scheme of a satellite optoelectronic spectrophotometer for measuring the total content of atmospheric ozone and other gas components of the atmosphere, which has increased precision, smaller weight and energy consumption, increased space and time resolution, quickness of reaction and increased volume of useful information. The object of the paper is the design of an appliance which ensures research of ozone content in atmosphere from the board of a satellite

[Assessment of tooth bleaching efficacy with spectrophotometer].

Science.gov (United States)

Zhu, Wenhao; Liu, Chang; Pan, Jie

2014-06-01

To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

An ultraviolet-visible spectrophotometer automation system. Part 3: Program documentation

Science.gov (United States)

Roth, G. S.; Teuschler, J. M.; Budde, W. L.

1982-07-01

The Ultraviolet-Visible Spectrophotometer (UVVIS) automation system accomplishes 'on-line' spectrophotometric quality assurance determinations, report generations, plot generations and data reduction for chlorophyll or color analysis. This system also has the capability to process manually entered data for the analysis of chlorophyll or color. For each program of the UVVIS system, this document contains a program description, flowchart, variable dictionary, code listing, and symbol cross-reference table. Also included are descriptions of file structures and of routines common to all automated analyses. The programs are written in Data General extended BASIC, Revision 4.3, under the RDOS operating systems, Revision 6.2. The BASIC code has been enhanced for real-time data acquisition, which is accomplished by CALLS to assembly language subroutines. Two other related publications are 'An Ultraviolet-Visible Spectrophotometer Automation System - Part I Functional Specifications,' and 'An Ultraviolet-Visible Spectrophotometer Automation System - Part II User's Guide.'

Development of Raman spectrophotometer

International Nuclear Information System (INIS)

Adam, A.I.

2008-05-01

In this work, the Raman spectrophotometer HG.2S Jobin Yvon rebuilt and developed, the Raman setup provided as a gift for Neelian University from Amsterdam University. The main parts, which were replaced, include monochromator, an air-cooled photomultiplier tube RCA IP 28, log amplifier, hand scanning lab VIEW card for computer interfacing. The components assembled and the whole device was tested successfully. The developed setup was checked using some standard solutions, which showed perfect consistency with literature in the references and published papers. Solutions included hexane, cyclohexane, carbon tetrachloride, benzene and sodium sulfate.(Author)

Cuvette and method for measuring refractive index in a spectrophotometer

DEFF Research Database (Denmark)

2017-01-01

Embodiments of the present invention include a cuvette (100) for use in determining a refractive index of a sample matter in a spectrophotometer (600), the cuvette comprising a container (102) for holding the sample matter, the container (102) having an entry window (121) that allows input...... or integrally formed in the container and arranged in the radiation path, the photonic crystal having a grating part (111) causing a reflectance spectrum of the photonic crystal to exhibit a resonance. A spectrophotometer is also provided....

Compensation for the temperature drift of the wavelength adjustment in an acoustooptic spectrophotometer

International Nuclear Information System (INIS)

Vilenskii, A V; Lysoi, B G; Cherednichenko, O B

2002-01-01

It is shown that the temperature drift of the wavelength adjustment in acoustooptic spectrophotometers can be compensated by using the reference channel of the spectrophotometer in which the absorption lines of neodymium-doped yttrium - aluminium garnet are employed as reference lines.

Fundamental studies to develop certified reference material to calibrate spectrophotometer in the ultraviolet region

International Nuclear Information System (INIS)

Da Conceição, F C; Borges, P P; Gomes, J F S

2016-01-01

Spectrophotometry is the technique used in a great number of laboratories around the world. Quantitative determination of a high number of inorganic, organic and biological species can be made by spectrophotometry using calibrated spectrophotometers. International standards require the use of optical filters to perform the calibration of spectrophotometers. One of the recommended materials is the crystalline potassium dichromate (K_2Cr_2O_7), which is used to prepare solutions in specific concentrations for calibration or verification of spectrophotometers in the ultraviolet (UV) spectral regions. This paper presents the results concerning the fundamental studies for developing a certified reference material (CRM) of crystalline potassium dichromate to be used as standard of spectrophotometers in order to contribute to reliable quantitative analyses. (paper)

Filter indexing for spectrophotometer system

International Nuclear Information System (INIS)

Chamran, M.M.; Scott, L.B.; Williams, P.B.

1982-01-01

A spectrophotometer system has an optical system for transmitting a beam from a source at select wavelengths onto a detector. A plurality of filters are positioned in a tray. A stepper mechanism indexes the tray along a path. A microcomputer controls the stepper mechanism and the optical system. The wavelength is successively changed over a range, the tray is indexed to move a select filter into the beam at a predetermined wavelength and the changing is discontinued during indexing

Non-focusing optics spectrophotometer, and methods of use

Science.gov (United States)

Kramer, David M.; Sacksteder, Colette A.

2004-11-02

In one aspect, the present invention provides kinetic spectrophotometers that each comprise: (a) a light source; and (b) a compound parabolic concentrator disposed to receive light from the light source and configured to (1) intensify and diffuse the light received from the light source, and (2) direct the intensified and diffused light onto a sample. In other aspects, the present invention provides methods for measuring a photosynthetic parameter, the methods comprising the steps of: (a) illuminating a plant leaf until steady-state photosynthesis is achieved; (b) subjecting the illuminated plant leaf to a period of darkness; (c) using a kinetic spectrophotometer of the invention to collect spectral data from the plant leaf treated in accordance with steps (a) and (b); and (d) determining a value for a photosynthetic parameter from the spectral data.

Brewer spectrophotometer measurements in the Canadian Arctic

Science.gov (United States)

Kerr, J. B.; Evans, W. F. J.

1988-01-01

In the winters of 1987 and 1988 measurements were conducted with the Brewer Spectrophotometer at Alert (82.5 N) and Resolute (74.5 N). The measurements were conducted as part of our Canadian Program to search for an Arctic Ozone Hole (CANOZE). Ozone measurements were conducted in the months of December, January and February using the moon as a light source. The total ozone measurements will be compared with ozonesonde profiles, from ECC sondes, flown once per week from Alert and Resolute. A modified Brewer Spectrophotometer was used in a special study to search for chlorine dioxide at Alert in March 1987. Ground based observations at Saskatoon in February and at Alert in March 1987 failed to detect any measureable chlorine dioxide. Interference from another absorbing gas, which we speculate may be nitrous acid, prevented the measurements at the low levels of chlorine dioxide detected in the Southern Hemisphere by Solomon et al.

Measurement of protein-like fluorescence in river and waste water using a handheld spectrophotometer.

Science.gov (United States)

Baker, Andy; Ward, David; Lieten, Shakti H; Periera, Ryan; Simpson, Ellie C; Slater, Malcolm

2004-07-01

Protein-like fluorescence intensity in rivers increases with increasing anthropogenic DOM inputs from sewerage and farm wastes. Here, a portable luminescence spectrophotometer was used to investigate if this technology could be used to provide both field scientists with a rapid pollution monitoring tool and process control engineers with a portable waste water monitoring device, through the measurement of river and waste water tryptophan-like fluorescence from a range of rivers in NE England and from effluents from within two waste water treatment plants. The portable spectrophotometer determined that waste waters and sewerage effluents had the highest tryptophan-like fluorescence intensity, urban streams had an intermediate tryptophan-like fluorescence intensity, and the upstream river samples of good water quality the lowest tryptophan-like fluorescence intensity. Replicate samples demonstrated that fluorescence intensity is reproducible to +/- 20% for low fluorescence, 'clean' river water samples and +/- 5% for urban water and waste waters. Correlations between fluorescence measured by the portable spectrophotometer with a conventional bench machine were 0.91; (Spearman's rho, n = 143), demonstrating that the portable spectrophotometer does correlate with tryptophan-like fluorescence intensity measured using the bench spectrophotometer.

Enzyme Activity Experiments Using a Simple Spectrophotometer

Science.gov (United States)

Hurlbut, Jeffrey A.; And Others

1977-01-01

Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

[An optical-fiber-sensor-based spectrophotometer for soil non-metallic nutrient determination].

Science.gov (United States)

He, Dong-xian; Hu, Juan-xiu; Lu, Shao-kun; He, Hou-yong

2012-01-01

In order to achieve rapid, convenient and efficient soil nutrient determination in soil testing and fertilizer recommendation, a portable optical-fiber-sensor-based spectrophotometer including immersed fiber sensor, flat field holographic concave grating, and diode array detector was developed for soil non-metallic nutrient determination. According to national standard of ultraviolet and visible spectrophotometer with JJG 178-2007, the wavelength accuracy and repeatability, baseline stability, transmittance accuracy and repeatability measured by the prototype instrument were satisfied with the national standard of III level; minimum spectral bandwidth, noise and excursion, and stray light were satisfied with the national standard of IV level. Significant linear relationships with slope of closing to 1 were found between the soil available nutrient contents including soil nitrate nitrogen, ammonia nitrogen, available phosphorus, available sulfur, available boron, and organic matter measured by the prototype instrument compared with that measured by two commercial single-beam-based and dual-beam-based spectrophotometers. No significant differences were revealed from the above comparison data. Therefore, the optical-fiber-sensor-based spectrophotometer can be used for rapid soil non-metallic nutrient determination with a high accuracy.

Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source.

Science.gov (United States)

Gombár, Melinda; Józsa, Éva; Braun, Mihály; Ősz, Katalin

2012-10-01

An inexpensive photoreactor using LED light sources and a fibre-optic CCD spectrophotometer as a detector was built by designing a special cell holder for standard 1.000 cm cuvettes. The use of this device was demonstrated by studying the aqueous photochemical reaction of 2,5-dichloro-1,4-benzoquinone. The developed method combines the highly quantitative data collection of CCD spectrophotometers with the possibility of illuminating the sample independently of the detecting light beam, which is a substantial improvement of the method using diode array spectrophotometers as photoreactors.

Evaluation of accuracy of shade selection using two spectrophotometer systems: Vita Easyshade and Degudent Shadepilot.

Science.gov (United States)

Kalantari, Mohammad Hassan; Ghoraishian, Seyed Ahmad; Mohaghegh, Mina

2017-01-01

The aim of this in vitro study was to evaluate the accuracy of shade matching using two spectrophotometric devices. Thirteen patients who require a full coverage restoration for one of their maxillary central incisors were selected while the adjacent central incisor was intact. 3 same frameworks were constructed for each tooth using computer-aided design and computer-aided manufacturing technology. Shade matching was performed using Vita Easyshade spectrophotometer, Shadepilot spectrophotometer, and Vitapan classical shade guide for the first, second, and third crown subsequently. After application, firing, and glazing of the porcelain, the color was evaluated and scored by five inspectors. Both spectrophotometric systems showed significantly better results than visual method ( P spectrophotometers ( P Spectrophotometers are a good substitute for visual color selection methods.

Structure analysis of biomolecules using synchrotron radiation circular dichroism spectrophotometer

International Nuclear Information System (INIS)

Gekko, Kunihiko; Matsuo, Koichi

2004-01-01

We constructed the vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer, which is capable of measuring circular dichroism spectra to 140 nm for aqueous solutions at temperature from -30 to 70degC, using a small-scale SR source at Hiroshima Synchrotron Radiation Center (HiSOR). This spectrophotometer was used for structural analyses of amino acids, saccharides, and proteins in water. The obtained results demonstrate that a synchrotron radiation VUVCD spectroscopy provides more detailed and new information on the structures of biomolecules, based on the high energy transitions of chromophores such as hydroxyl, acetal, and peptide groups. (author)

Atomic absorption spectrophotometer

International Nuclear Information System (INIS)

Stockdale, T. J.

1985-01-01

In atomic absorption spectrophotometer, a reference path may be provided for radiation which excludes the flame. This radiation provides a signal from a detector which varies only with the instrumental drift produced by variations in the radiation source brightness and by variations in detector gain. The signal can be used to compensate for drift in other signals received through a sample path including the flame. In the present invention, radiation passes through the sample path continuously during measurement, and only through the reference path between sample measurements. Movable mirrors shift the radiation between the paths upon externally applied commands. Conveniently, the reference path measurement is made while the flame is stabilized during the change between samples. The reference path measurements are stored and used to correct for drift

Development of a Novel Spectrophotometer for Biochemical Analyzer Based on Volume Holography Transmissive Grating and Linear CCD

International Nuclear Information System (INIS)

Ren Zhong; Liu Guodong; Huang Zhen; Zeng Lvming; Dai Longmin

2011-01-01

The classical surface-embossed plane and concave grating are usually used as the diffraction grating in some spectrophotometers. But the minute cracks are produced on the surface of the gratings' grooves, which leads to generate the stray-light and decrease the efficiency of instrument. Therefore, a novel custom-built spectrophotometer for BCA is developed in this paper. Meanwhile, the volume holography transmissive (VHT) grating is used as the diffraction grating in this spectrophotometer. Additionally, a high resolution CCD and data acquisition (DAQ) card with combined the virtual software platform based on LabVIEW are used to design the spectral acquisition and analysis system. Experimental results show that the spectral range and the diffraction efficiency of the spectrophotometer for BCA are greatly increased. The spectral range of the spectrophotometer for BCA can reach 300-1000 nm, its wavelength resolution can reach 1nm. And, it uses the back-splitting-light technology and multi-channel parallel analysis. Compared with other same types, this spectrophotometer has many advantages, such as, higher efficiency, simpler algorithm, higher accuracy, cheaper cost and fewer stray-light and higher imaging quality, etc. Therefore, this spectrophotometer for BCA based on VHT grating will has the greatly potential values in the fields of the biochemical or medical research.

Shutter mechanism for spacecraft spectrophotometer

Science.gov (United States)

Weilbach, A.

1972-01-01

A shutter mechanism is described for the backscatter ultraviolet spectrophotometer experiment on the Nimbus D satellite. The purpose of the experiment is to determine spatial distribution of atmospheric ozone from measurements of ultraviolet radiation backscattered by the earth's atmosphere. The system consists of two independent, rotary cylinder shutters, controlled by a dual star Geneva mechanism, and driven by a single stepper motor. A single driver controls a combination of two independently driven Geneva stars. Design considerations involved the use of low friction, nonmetallic materials.

Spectrophotometer and ultrasound evaluation of late toxicity following breast-cancer radiotherapy.

Science.gov (United States)

Yoshida, E J; Chen, H; Torres, M A; Curran, W J; Liu, T

2011-10-01

Radiation-induced normal-tissue toxicities are common, complex, and distressing side effects that affect 90% of patients receiving breast-cancer radiotherapy and 40% of patients post radiotherapy. In this study, the authors investigated the use of spectrophotometry and ultrasound to quantitatively measure radiation-induced skin discoloration and subcutaneous-tissue fibrosis. The study's purpose is to determine whether skin discoloration correlates with the development of fibrosis in breast-cancer radiotherapy. Eighteen breast-cancer patients were enrolled in our initial study. All patients were previously treated with a standard course of radiation, and the median follow-up time was 22 months. The treated and untreated breasts were scanned with a spectrophotometer and an ultrasound. Two spectrophotometer parameters-melanin and erythema indices-were used to quantitatively assess skin discoloration. Two ultrasound parameters-skin thickness and Pearson coefficient of the hypodermis-were used to quantitatively assess severity of fibrosis. These measurements were correlated with clinical assessments (RTOG late morbidity scores). Significant measurement differences between the treated and contralateral breasts were observed among all patients: 27.3% mean increase in skin thickness (p spectrophotometer parameters do not correlate with ultrasound parameters. Spectrophotometry and quantitative ultrasound are objective tools that assess radiation-induced tissue injury. Spectrophotometer parameters did not correlate with those of quantitative ultrasound suggesting that skin discoloration cannot be used as a marker for subcutaneous fibrosis. These tools may prove useful for the reduction of radiation morbidities and improvement of patient quality of life.

Fiber optic modification of a diode array spectrophotometer

International Nuclear Information System (INIS)

Van Hare, D.R.; Prather, W.S.

1986-01-01

Fiber optics were adapted to a Hewlett-Packard diode array spectrophotometer to permit the analysis of radioactive samples without risking contamination of the instrument. Instrument performance was not compromised by the fiber optics. The instrument is in routine use at the Savannah River Plant control laboratories

The Spectrophotometer II: A Module on the Spectral Properties of Light. Tech Physics Series.

Science.gov (United States)

Frank, Nathaniel; And Others

This module is designed to give the learner an understanding of the nature of light and how its properties are used in the design of spectrophotometers. Problems promote the use of spectrophotometers in qualitative analysis, the optical elements used in a monochromator, and the physical properties of the prism and the diffraction grating. Other…

Shade determination using camouflaged visual shade guides and an electronic spectrophotometer.

Science.gov (United States)

Kvalheim, S F; Øilo, M

2014-03-01

The aim of the present study was to compare a camouflaged visual shade guide to a spectrophotometer designed for restorative dentistry. Two operators performed analyses of 66 subjects. One central upper incisor was measured four times by each operator; twice with a camouflaged visual shade guide and twice with a spectrophotometer Both methods had acceptable repeatability rates, but the electronic shade determination showed higher repeatability. In general, the electronically determined shades were darker than the visually determined shades. The use of a camouflaged visual shade guide seems to be an adequate method to reduce operator bias.

A multi-channel coronal spectrophotometer.

Science.gov (United States)

Landman, D. A.; Orrall, F. Q.; Zane, R.

1973-01-01

We describe a new multi-channel coronal spectrophotometer system, presently being installed at Mees Solar Observatory, Mount Haleakala, Maui. The apparatus is designed to record and interpret intensities from many sections of the visible and near-visible spectral regions simultaneously, with relatively high spatial and temporal resolution. The detector, a thermoelectrically cooled silicon vidicon camera tube, has its central target area divided into a rectangular array of about 100,000 pixels and is read out in a slow-scan (about 2 sec/frame) mode. Instrument functioning is entirely under PDP 11/45 computer control, and interfacing is via the CAMAC system.

Versatile IEEE-488 data acquisition and control routines for a diode array spectrophotometer

OpenAIRE

Shiundu, Paul M.; Wade, Adrian P.

1991-01-01

The UV-visible diode array spectrophotometer is a work-horse instrument for many laboratories. This article provides simple data acquisition and control routines in Microsoft QuickBasic for a HP-8452A diode array spectrophotometer interfaced to an IBM PC/XT/AT, or compatible, microcomputer. These allow capture of full spectra and measure absorbance at one or several wavelengths at preset time intervals. The variance in absorbance at each wavelength is available as an option.

Development of an ultra-compact mid-infrared attenuated total reflectance spectrophotometer

Science.gov (United States)

Kim, Dong Soo; Lee, Tae-Ro; Yoon, Gilwon

2014-07-01

Mid-infrared spectroscopy has been an important tool widely used for qualitative analysis in various fields. However, portable or personal use is size and cost prohibitive for either Fourier transform infrared or attenuated total reflectance (ATR) spectrophotometers. In this study, we developed an ultra-compact ATR spectrophotometer whose frequency band was 5.5-11.0 μm. We used miniature components, such as a light source fabricated by semiconductor technology, a linear variable filter, and a pyro-electric array detector. There were no moving parts. Optimal design based on two light sources, a zippered configuration of the array detector and ATR optics could produce absorption spectra that might be used for qualitative analysis. A microprocessor synchronized the pulsed light sources and detector, and all the signals were processed digitally. The size was 13.5×8.5×3.5 cm3 and the weight was 300 grams. Due to its low cost, our spectrophotometer can replace many online monitoring devices. Another application could be for a u-healthcare system installed in the bathroom or attached to a smartphone for monitoring substances in body fluids.

Utilization of Android-base Smartphone to Support Handmade Spectrophotometer : A Preliminary Study

Science.gov (United States)

Ujiningtyas, R.; Apriliani, E.; Yohana, I.; Afrillianti, L.; Hikmah, N.; Kurniawan, C.

2018-04-01

Visible spectrophotometer is a powerful instrument in chemistry. We can identify the chemical species base on their specific color and then we can also determine the amount of the species using the spectrophotometer. However, the availability of visible spectrophotometer still limited, particularly for education. This affect the skill of student to have experience on handling the instrumentation. On the other hand, the communication technology creates an opportunity for student to explore their smart feature, mainly the camera. The objective of this research is to make an application that utilize the camera feature as a detector for handmade visible spectrophotometer. The software have been made based on android program, and we name it as Spectrophone®. The spectrophotometer consists of an acrylic body, sample compartment, and light sources (USB-LED lamp powered by 6600 mAh battery). Before reach the sample, the light source was filtered using colored-mica plastic. The spectrophone® apps utilize the camera to detect the color based on its RGB composition. A different colored solution will show a different RGB composition based on the concentration and specific absorbance wavelength. We then can choose one type of color composition, R or G or B only to be converted as an absorbance using -Log (Cs/Co), where Cs and Co are color composition of sample and blank, respectively. The calibration curve of metilen blue measured. In a red (R) composition, the regression is not linear (R2=0.78) compare to the result of UV-Vis spectrophotomer model Spectroquant Pharo 300 (R2=0.8053). This measurement result shows that The Spectrophone® still need to be evaluated and corrected. One problem than can we identify that the diameter of pick point of RGB composition is too wide and this will affect the reading color composition. Next, we will fix the problem and in advance we will apply this Spectrophone® in a wide scale.

Versatile IEEE-488 data acquisition and control routines for a diode array spectrophotometer

Science.gov (United States)

Shiundu, Paul M.

1991-01-01

The UV-visible diode array spectrophotometer is a work-horse instrument for many laboratories. This article provides simple data acquisition and control routines in Microsoft QuickBasic for a HP-8452A diode array spectrophotometer interfaced to an IBM PC/XT/AT, or compatible, microcomputer. These allow capture of full spectra and measure absorbance at one or several wavelengths at preset time intervals. The variance in absorbance at each wavelength is available as an option. PMID:18924888

Dobson spectrophotometer ozone measurements during international ozone rocketsonde intercomparison

Science.gov (United States)

Parsons, C. L.

1980-01-01

Measurements of the total ozone content of the atmosphere, made with seven ground based instruments at a site near Wallops Island, Virginia, are discussed in terms for serving as control values with which the rocketborne sensor data products can be compared. These products are profiles of O3 concentration with altitude. By integrating over the range of altitudes from the surface to the rocket apogee and by appropriately estimating the residual ozone amount from apogee to the top of the atmosphere, a total ozone amount can be computed from the profiles that can be directly compared with the ground based instrumentation results. Dobson spectrophotometers were used for two of the ground-based instruments. Preliminary data collected during the IORI from Dobson spectrophotometers 72 and 38 are presented. The agreement between the two and the variability of total ozone overburden through the experiment period are discussed.

[Comparison of color reappearance between metal-ceram restoration and foundry-ceram restoration using crystaleye spectrophotometer].

Science.gov (United States)

Shi, Tao; Zhang, Ning; Kong, Fan-wen; Zhan, De-song

2010-10-01

To study the color reappearance effect of metal-ceram restoration and foundry-ceram restoration using Crystaleye spectrophotometer. 58 metal-ceram restorations and 58 foundry-ceram restorations according to the result of the Crystaleye spectrophotometer were made respectively. The deltaE between restorations and natural teeth as referenced were analyzed. And satisfaction of dentists and patients were evaluated. The deltaE between metal-ceram restorations and natural teeth was 7.13 +/- 0.74. The deltaE between foundry-ceram restorations and teeth was 1.47 +/- 0.84. There were statistical differences between the deltaE (P spectrophotometer can provide accurate reference for foundry-ceram restoration, but for metal-ceram restoration it is not accurate.

Aberration Correction in the Brewer Spectrophotometer

International Nuclear Information System (INIS)

Johnston, J.E.; Kerr, J.B.; McElroy, C.T.; Wardle, D.I.

2000-01-01

The optical design of the Brewer Spectrophotometer has been optimised for measurements in the 300-320 nm wavelength range. An aberration resolution limit that is much less than the 0.6 nm FWHM (full width at half maximum) is achieved by using an Ebert-Fastie spectrometer design, modified by the inclusion tilted lens that optimises performance at 310 nm. The small contribution of the remaining aberration to the measured instrument function is critical to radiometric measurement quality. Ramifications of this design to the development of instrumentation with enhanced scanning abilities are discussed. (author)

Far-infrared spectrophotometer for astronomical observations

Science.gov (United States)

Moseley, H.; Silverberg, R. F.

1981-01-01

A liquid-helium-cooled far infrared spectrophotometer was built and used to make low resolution observations of the continua of several kinds of astronomical objects using the Kuiper Airborne Observatory. This instrument fills a gap in both sensitivity to continuum sources and spectral resolution between the broadband photometers with lambda/Delta lambda approximately 1 and spectrometers with lambda/Delta lambda greater than 50. While designed primarily to study planetary nebulae, the instrument permits study of the shape of the continua of many weak sources which cannot easily be observed with high resolution systems.

Spectrophotometer-Integrating-Sphere System for Computing Solar Absorptance

Science.gov (United States)

Witte, William G., Jr.; Slemp, Wayne S.; Perry, John E., Jr.

1991-01-01

A commercially available ultraviolet, visible, near-infrared spectrophotometer was modified to utilize an 8-inch-diameter modified Edwards-type integrated sphere. Software was written so that the reflectance spectra could be used to obtain solar absorptance values of 1-inch-diameter specimens. A descriptions of the system, spectral reflectance, and software for calculation of solar absorptance from reflectance data are presented.

Vacuum-ultraviolet circular dichroism of amino acids as revealed by synchrotron radiation spectrophotometer

International Nuclear Information System (INIS)

Matsuo, Koichi; Matsushima, Yosuke; Fukuyama, Takayuki; Gekko, Kunihiko; Senba, Shinya

2002-01-01

We succeeded in constructing a vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer with a small-scale synchrotron radiation source (0.7 GeV) at Hiroshima Synchrotron Radiation Center (HiSOR). This VUVCD system revealed for the first time the CD spectra of amino acids in aqueous media in the 310-140 nm region under high vacuum. These data, which cannot be observed by any types of existing CD spectrophotometers, now open a new field in the structural analysis of biomaterials on a basis of the higher energy transition of chromophores. (author)

Objective evaluation of whiteness of cooked rice and rice cakes using a portable spectrophotometer.

Science.gov (United States)

Goto, Hajime; Asanome, Noriyuki; Suzuki, Keitaro; Sano, Tomoyoshi; Saito, Hiroshi; Abe, Yohei; Chuba, Masaru; Nishio, Takeshi

2014-03-01

The whiteness of cooked rice and rice cakes was evaluated using a portable spectrophotometer with a whiteness index (WI). Also, by using boiled rice for measurement of Mido values by Mido Meter, it was possible to infer the whiteness of cooked rice without rice cooking. In the analysis of varietal differences of cooked rice, 'Tsuyahime', 'Koshihikari' and 'Koshinokaori' showed high whiteness, while 'Satonoyuki' had inferior whiteness. The whiteness of rice cakes made from 'Koyukimochi' and 'Dewanomochi' was higher than the whiteness of those made from 'Himenomochi' and 'Koganemochi'. While there was a significant correlation (r = 0.84) between WI values and whiteness scores of cooked rice by the sensory test, no correlation was detected between the whiteness scores and Mido values, indicating that the values obtained by a spectrophotometer differ from those obtained by a Mido Meter. Thus, a spectrophotometer may be a novel device for measurement of rice eating quality.

A comparison between a tristimulus colorimeter (Minolta ChromaMeter CR-200) and two spectrophotometers (Minolta Spectrophotometer CM-508i and CM-2002). Quantification of UV-B induced erythema in a hairless guinea pig model.

Science.gov (United States)

Fullerton, A; Keiding, J

1997-11-01

A comparison was made between a tristimulus colorimeter (Minolta ChromaMeter CR 200) and two spectrophotometers (Minolta CM-508i and CM-2002). The object was to compare skin colour data in the CIE 1976 L*a*d*colour space system obtained with the different instruments after UV-B exposure. Guinea pigs were exposed on their dorsal trunk with UV-B light for different time periods. Skin colour in the L*a*b* system was measured 6 and 24 h after exposure. Reproducible and objective measurements expressed in the CIE system were obtained with all three instruments. A strong correlation was found between the Minolta Chromameter CR200 and each of the two spectrophotometers. However, absolute values found with the Minolta ChromaMeter CR 200, especially for b*, differed from values obtained with the two spectrophotometers. The instruments were, despite minor inter-instrumental variation, suited for objective evaluation of erythema. The spectrophotometers were somewhat cumbersome to use due to their heavy weight and difficulties in positioning within the test sites; the Minolta CromaMeter CR200 (or later versions) is thus preferable for simple routine measurements. Use of the spectophotometers appears only indicated where specific information about skin pigments or photoactive substances relative to wavelength is needed.

Palmtop spectrophotometer for DNA and protein measurement in micro-nanoliter assays

International Nuclear Information System (INIS)

Qiu Tian; Huang Guoliang; Yang Xiaoyong; Ma Li; Yang Xu

2011-01-01

Spectrophotometer, an important tool in life science, medicine, and analytical fields, usually uses an optical path of 10 mm or more for absorbance measurement of UV light. This corresponds to a sample consumption of ≥ 50 μL in volume and a narrow measuring range of 0.5-50 ng/μL for nucleic acid samples and 0.05-2 mg/mL for protein samples. Higher concentrations must be diluted for measurement. In this paper, we developed an advanced palmtop spectrophotometer for the measurement of both DNA and protein concentrations in micro-nanoliter assays. We constructed a fiber transmission and a fiber reflection absorbance detection scheme illuminated by either UV-LED or deuterium lamp. The sensitivity of 0.5 ng/μL and a wide measuring range of 0.5-2000 ng/μL in concentrations were obtained for DNA, and the sensitivity of 0.05 mg/mL and a wide measuring range of 0.05-100 mg/mL were also obtained for protein. However, sample consumption is only 1 μL in volume for fiber transmission detection scheme and 500 nL for fiber reflection detection scheme. The linear correlation coefficient of measured concentrations to theoretical concentrations is greater than 0.99. With the profit of this work, a miniaturized spectrophotometer with better sensitivity and wider measuring range can be produced for analytical applications.

Isosbestic points in the quality control oF spectrophotometers

International Nuclear Information System (INIS)

Oliveira, E.M. de.

1987-01-01

The methodology and results of quality control of spectrophotometers are reported and the calibrating of the monochromator by isosbestic points is presented. Four colorimetric indicators are used. The absorption curves (in acid and alkaline media) and mathematic determination of the common junction point are used for indicated the isosbetic points. (M.A.C.) [pt

Last improvements of the DTC 1000 spectrophotometer

International Nuclear Information System (INIS)

Blanc, F.

1988-01-01

The DTC 1000 spectrophotometer, based on optical fibers and photodiode array was developed for Pu(IV) measurement in fuel reprocessing. The apparatus takes advantage of experience acquired in optical fibers instrumentation and of the study of gamma radiation effects on fibers. This paper give the complete evolution of these last months (memory, hardware, software, background noise). But the principle of the apparatus and examples of results obtained on americium and plutonium on a previous version of the apparatus are recalled. 17 figs., 6 refs [fr

Using a digital multimeter to capture spectral information generated by a spectrophotometer broadcast / atomic absorption

International Nuclear Information System (INIS)

Villalobos Chaves, Alberto E.

2006-01-01

Spectral analysis capability of the information generated by a spectrophotometer broadcast / shimadzu AA 640-13 atomic absorption has increased, through the capture of data, using a digital multimeter as the interface between the spectrophotometer and a computer. To facilitate the identification of analytes was created Chromulan format files for the 99 chemical elements reported in the literature, and covering the region between 200 nm and 900 nm, the subject of this study. (author) [es

A low cost short wave near infrared spectrophotometer: application for determination of quality parameters of diesel fuel.

Science.gov (United States)

Gonzaga, Fabiano Barbieri; Pasquini, Celio

2010-06-18

A low cost absorption spectrophotometer for the short wave near infrared spectral region (850-1050 nm) is described. The spectrophotometer is basically composed of a conventional dichroic lamp, a long-pass filter, a sample cell and a Czerny-Turner type polychromator coupled to a 1024 pixel non-cooled photodiode array. A preliminary evaluation of the spectrophotometer showed good repeatability of the first derivative of the spectra at a constant room temperature and the possibility of assigning some spectral regions to different C-H stretching third overtones. Finally, the spectrophotometer was successfully applied for the analysis of diesel samples and the determination of some of their quality parameters using partial least squares calibration models. The values found for the root mean square error of prediction using external validation were 0.5 for the cetane index and from 2.5 to 5.0 degrees C for the temperatures achieved during distillation when obtaining 10, 50, 85, and 90% (v/v) of the distilled sample, respectively. 2010 Elsevier B.V. All rights reserved.

An extinction scale-expansion unit for the Beckman DK2 spectrophotometer

Science.gov (United States)

Dixon, M.

1967-01-01

The paper describes a simple but accurate unit for the Beckman DK2 recording spectrophotometer, whereby any 0·1 section of the extinction (`absorbance') scale may be expanded tenfold, while preserving complete linearity in extinction. PMID:6048800

Determination of the Performance Parameters of a Spectrophotometer: An Advanced Experiment.

Science.gov (United States)

Cope, Virgil W.

1978-01-01

Describes an advanced analytical chemistry laboratory experiment developed for the determination of the performance parameters of a spectrophotometer. Among the parameters are the baseline linearity with wavelength, wavelength accuracy and respectability, stray light, noise level and pen response time. (HM)

Portable visible and near-infrared spectrophotometer for triglyceride measurements.

Science.gov (United States)

Kobayashi, Takanori; Kato, Yukiko Hakariya; Tsukamoto, Megumi; Ikuta, Kazuyoshi; Sakudo, Akikazu

2009-01-01

An affordable and portable machine is required for the practical use of visible and near-infrared (Vis-NIR) spectroscopy. A portable fruit tester comprising a Vis-NIR spectrophotometer was modified for use in the transmittance mode and employed to quantify triglyceride levels in serum in combination with a chemometric analysis. Transmittance spectra collected in the 600- to 1100-nm region were subjected to a partial least-squares regression analysis and leave-out cross-validation to develop a chemometrics model for predicting triglyceride concentrations in serum. The model yielded a coefficient of determination in cross-validation (R2VAL) of 0.7831 with a standard error of cross-validation (SECV) of 43.68 mg/dl. The detection limit of the model was 148.79 mg/dl. Furthermore, masked samples predicted by the model yielded a coefficient of determination in prediction (R2PRED) of 0.6856 with a standard error of prediction (SEP) and detection limit of 61.54 and 159.38 mg/dl, respectively. The portable Vis-NIR spectrophotometer may prove convenient for the measurement of triglyceride concentrations in serum, although before practical use there remain obstacles, which are discussed.

Application of microplate spectrophotometer in determination of apparent amylose content and mutant selection in rice

International Nuclear Information System (INIS)

Zhu Xiaoyang; Shen Shengquan; Chen Wenyue; Shu Qingyao

2004-01-01

The application of automatic microplate spectrophotometer (SpectraMax 190, Sunnyvale, USA) was investigated for measurement of apparent amylose content (AAC) of rice grains. By using five rice varieties (IR24, Iri371, Z413, KMD1 and Xiushui 11), a microplate spectrophotometer-facilitated AAC measurement system was established with similar accuracy to that of standard protocol (NY147-88). In this system, sample was treated as NY147-88, but directly stained in a microplate and the OD values of each sample were determined by a microplate spectrophotometer. A regression equation was established by using the AAC and OD value of standard samples, and the AAC of test samples were estimated by using the equation. The system is simple, accurate and high-throughput. By using this system, about 1500 progenies of M 3 seeds (harvested from individual M 2 plants) were screened for putative AAC mutants, from which one mutant line ZXY16 was developed with a middle AAC of about 16%

Comparison of accuracies of an intraoral spectrophotometer and conventional visual method for shade matching using two shade guide systems.

Science.gov (United States)

Parameswaran, Vidhya; Anilkumar, S; Lylajam, S; Rajesh, C; Narayan, Vivek

2016-01-01

This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both methods and effectiveness of two shade guides with either method. In the visual method, 10 examiners with normal color vision matched target control shade tabs taken from the two shade guides (VITAPAN Classical™ and VITAPAN 3D Master™) with other full sets of the respective shade guides. Each tab was matched 3 times to determine repeatability of visual examiners. The spectrophotometric shade matching was performed by two independent examiners using an intraoral spectrophotometer (VITA Easyshade™) with five repetitions for each tab. Results revealed that visual method had greater accuracy than the spectrophotometer. The spectrophotometer; however, exhibited significantly better interrater agreement as compared to the visual method. While VITAPAN Classical shade guide was more accurate with the spectrophotometer, VITAPAN 3D Master shade guide proved better with visual method. This in vitro study clearly delineates the advantages and limitations of both methods. There were significant differences between the methods with the visual method producing more accurate results than the spectrophotometric method. The spectrophotometer showed far better interrater agreement scores irrespective of the shade guide used. Even though visual shade matching is subjective, it is not inferior and should not be underrated. Judicious combination of both techniques is imperative to attain a successful and esthetic outcome.

Chemical Fouling Reduction of a Submersible Steel Spectrophotometer in Estuarine Environments Using a Sacrificial Zinc Anode.

Science.gov (United States)

Tait, Zachary S; Thompson, Megan; Stubbins, Aron

2015-07-01

The availability of in situ spectrophotometers, such as the S::CAN spectro::lyser, has expanded the possibilities for high-frequency water quality data collection. However, biological and chemical fouling can degrade the performance of in situ spectrophotometers, especially in saline environments with rapid flow rates. A complex freshwater washing system has been previously designed to reduce chemical fouling for the S::CAN spectro::lyser spectrophotometer. In the current study, we present a simpler, cheaper alternative: the attachment of a sacrificial zinc anode. Results are presented detailing the S::CAN spectro::lyser performance with and without the addition of the sacrificial anode. Attachment of the zinc anode provided efficient corrosion protection during 2-wk deployments in a highly dynamic (average tidal range, 2.5 m) saline tidal saltmarsh creek at Groves Creek, Skidaway Institute of Oceanography, Savannah, GA. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

UV-observations with a Brewer spectrophotometer at Hohenpeissenberg

Science.gov (United States)

Vandersee, Winfried; Koehler, U.

1994-01-01

Regular spectral UV-B measurements with a Brewer spectrophotometer have been performed at Hohenpeissenberg since 1990. Intercomparison of the Brewer instrument with other UV-B monitoring devices have shown agreement to within plus or minus 10 percent. Comparisons of UV-B spectra measured on fair weather days reveal the well known increasing influence of ozone on UV-B irradiance with decreasing wavelengths. The integral amplification factor the erythemal irradiance reaches values up to 2.8, which can be diminished by increasing turbidity. The influence of cirrus cloud on the UV-B is also shown.

Results of international Dobson spectrophotometer calibrations at Arosa, Switzerland, 1990

Science.gov (United States)

Grass, R. D.; Komhyr, W. D.; Koenig, G. L.; Evans, R. D.

1994-01-01

An international comparison of Dobson ozone spectrophotometers, organized and partially funded by the World Meteorological Organization (WMO), was held at the Lichtklimatisches Observatorium (LKO) in Arosa, Switzerland, July-August 1990. Countries participating with a total of 18 Dobson instruments were Belgium, Czechoslovakia, Denmark, Germany, Greece, Hungary, Iceland, Norway, Poland, Portugal, Rumania, Spain, Switzerland, the United Kingdom, the United States, and the United Soviet Socialist Republics. The reference standard instrument for the comparison was U.S.A. Secondary Standard Dobson Spectrophotometer 65 maintained by the NOAA Climate and Monitoring and Diagnostics Laboratory, Boulder, Colorado. The mean difference in ozone obtained with the Dobson instruments relative to Dobson instrument 65, calculated from ADDSGQP observations in the air mass range 1.15-3.2, was minus 1.0 plus or minus 1.2 (1 sigma) percent. The WMO Standard Brewer Spectrometer 39 also participated. In the mean, the Brewer instrument measured 0.6 plus or minus 0.2 (1 sigma) percent more ozone than did Dobson instrument 65. Results are presented, also, of ozone vertical profile measurements made with the Dobson instruments, two Brewer spectrometers, a LIDAR, a balloon ozonesonde flown from Hohenpeissenberg, Germany, and balloon ozonesondes flown from Payerne, Switzerland.

Use of the SF-8 detection spectrophotometer for measuring absorption spectra of molten salts

International Nuclear Information System (INIS)

Kotlin, V.P.; Barbanel', Yu.A.

1975-01-01

Three versions of the use of the SF-8 spectrophotometer for high-temperature measurements are described: 1) based on the standard optical scheme at temperatures of up to 400 0 C; 2) based on a modified one-wave scheme; 3) based on a modified twin-wave scheme. The external heater used in the schemes 2 and 3 ensures that measurements can be performed at temperatures of up to 1000 0 C. In order to obtain the spectra of thin-layer samples vessels with an insert are used. For operation of the spectrophotometer according to the schemes 2 and 3 te heater may in principle be replaced by a cryostat or some other external device

Online analysis by a fiber-optic diode array spectrophotometer

International Nuclear Information System (INIS)

Van Hare, D.R.; Prather, W.S.; O'Rourke, P.E.

1987-01-01

An online photometric analyzer has been developed which can make remote measurements over the 350 to 900 nm region at distances of up to 100 feet. The analyzer consists of a commercially available diode array spectrophotometer interfaced to a fiber-optic multiplexer to allow online monitoring of up to ten locations sequentially. The development of the fiber-optic interface is discussed and data from several online applications are presented to demonstrate the capabilities of the measurement system

Automated spectrophotometer for plutonium and uranium determination

International Nuclear Information System (INIS)

Jackson, D.D.; Hodgkins, D.J.; Hollen, R.M.; Rein, J.E.

1975-09-01

The automated spectrophotometer described is the first in a planned series of automated instruments for determining plutonium and uranium in nuclear fuel cycle materials. It has a throughput rate of 5 min per sample and uses a highly specific method of analysis for these elements. The range of plutonium and uranium measured is 0.5 to 14 mg and 1 to 14 mg, respectively, in 0.5 ml or less of solution with an option to pre-evaporate larger volumes. The precision of the measurements is about 0.02 mg standard deviation over the range corresponding to about 2 rel percent at the 1-mg level and 0.2 rel percent at the 10-mg level. The method of analysis involves the extraction of tetrapropylammonium plutonyl and uranyl trinitrate complexes into 2-nitropropane and the measurement of the optical absorbances in the organic phase at unique peak wavelengths. Various aspects of the chemistry associated with the method are presented. The automated spectrophotometer features a turntable that rotates as many as 24 samples in tubes to a series of stations for the sequential chemical operations of reagent addition and phase mixing to effect extraction, and then to a station for the absorbance measurement. With this system, the complications of sample transfers and flow-through cells are avoided. The absorbance measurement system features highly stable interference filters and a microcomputer that controls the timing sequence and operation of the system components. Output is a paper tape printout of three numbers: a four-digit number proportional to the quantity of plutonium or uranium, a two-digit number that designates the position of the tube in the turntable, and a one-digit number that designates whether plutonium or uranium was determined. Details of the mechanical and electrical components of the instrument and of the hardware and software aspects of the computerized control system are provided

Quantitative analysis of skin reaction by reflectance spectrophotometer. Acute reaction following proton therapy

International Nuclear Information System (INIS)

Kawashima, Mitsuhiko; Okumura, Toshiyuki; Tatsuzaki, Hideo; Tsuji, Hiroshi; Tsujii, Hirohiko.

1994-01-01

Acute reactions induced by proton irradiation were measured using a reflectance spectrophotometer, which is commonly used in the printing and textile industries. In this method, the skin color was expressed by three parameters, lightness (L * ), chroma (C * ) and hue (h). At first, in order to evaluate the accuracy of this spectrophotometer, the skin color of a normal volunteer was measured 100 times. The values of the three parameters for normal skin were as follows (mean values and standard deviation), L * : 68.64±0.29, C * : 19.08±0.13, h: 69.41±0.76. The standard deviations with regard to L * and h, were considered to be sufficiently small when compared with the changes of these parameters (prefix: Δ) in the irradiated sites (ΔL * * and h values significantly decreased with time, and the L * values were highly correlated with elapsed treatment days. The h values had a relatively low linear correlation compared with L * . The C * values had no trends as the treatment period was extended. Among these parameters, the L * values were the most valuable for assessment of proton-induced skin reactions, and it was suggested that the L * values measured with this spectrophotometer were a useful index for showing biological effects induced by proton irradiation. Further experiments are needed to apply this method to quantify the biological effects induced by other forms of ionizing radiation. (author)

Authentic Performance in the Instrumental Analysis Laboratory: Building a Visible Spectrophotometer Prototype

Science.gov (United States)

Wilson, Mark V.; Wilson, Erin

2017-01-01

In this work we describe an authentic performance project for Instrumental Analysis in which students designed, built, and tested spectrophotometers made from simple components. The project addressed basic course content such as instrument design principles, UV-vis spectroscopy, and spectroscopic instrument components as well as skills such as…

Comparing predictive abilities of three visible-near infrared spectrophotometers for soil organic carbon and clay determination

DEFF Research Database (Denmark)

Knadel, Maria; Stenberg, Bo; Deng, Fan

2013-01-01

carbon (SOC) and clay calibrations for 194 Danish top soils. Scanning procedures for the three spectrophotometers where done according to uniform laboratory protocols. SOC and clay calibrations were performed using PLS regression. One third of the data was used as an independent test set. A range...... of spectral preprocessing methods was applied in search for model improvement. Validation for SOC content using an independent data set derived from all three spectrophotometers provided values of RMSEP between 0.45 and 0.52 %, R2=0.44-0.58 and RPD=1.3-1.5. Clay content was predicted with a higher precision...

Development of Simple and Precise Method of Arginine Determination in Rumen Fluid by Spectrophotometer

International Nuclear Information System (INIS)

Chacher, B.; Marghazani, I. B.; Liu, J. X.; Liu, H. Y.

2015-01-01

The objective of current study was to build up a convenient, economic and accurate procedure to determine arginine (ARG) concentration in rumen fluid. Rumen fluid was collected from 3 rumen fistulated Chinese Holstein dairy cows and added with or without (control) 1mmol/l unprotected ARG and blank (with only medium) in to syringe system in triplicate as a replicate. All syringes were incubated in water bath at 39 Degree C for 0, 2, 4, 6, 12 and 24 h and were terminated to measure the ARG concentration. Sakaguchi reaction method was used to analyze the ARG concentration in rumen fluid by determining the rumen degradation rate of protected and unprotected ARG. Temperature, time and absorbance were optimized in the procedure based on Sakaguchi reaction. Color consistency remained 4-6 min. The optimum temperature (0-5) Degree C was observed for maximum optical density 0.663 at wave length 500 nm. Minimum ARG that could be determined in rumen fluid by spectrophotometer was 4-5 μ g/ml. No significance (P>0.05) difference were observed between two results derived from spectrophotometer and amino acid analyzer methods. In conclusion, the spectrophotometer method of ARG determination in rumen fluid based on Sakaguchi reaction is easy, accurate, and economical and could be useful in learning ARG metabolism in the rumen. (author)

Correlation between skin color evaluation by skin color scale chart and narrowband reflectance spectrophotometer.

Science.gov (United States)

Treesirichod, Arucha; Chansakulporn, Somboon; Wattanapan, Pattra

2014-07-01

Various methods are available for the evaluation of skin color. A skin color scale chart is a convenient and inexpensive tool. However, the correlation between a skin color scale chart and objective measurement has not been evaluated. To assess the correlation between skin color evaluation done by a skin color scale chart (Felix von Luschan skin color chart) and a narrowband reflectance spectrophotometer (Mexameter MX18). The participants were evaluated for skin color by using the Felix von Luschan skin color chart (range 1-36) and a narrowband reflectance spectrophotometer (Mexameter MX18) in which the results of the measurements were expressed as Erythema (E) and Melanin (M) indices. Skin color was measured on four different anatomical skin sites from each participant on the medial aspect of the volar and the dorsal regions of both forearms. A total of 208 records from 52 participants were established. The majority of participants (19.2%) were rated with the skin color scale at the number 16 (range 14-33). The mean M plus E, M, and E indices were 498.9 ± 143.9, 230.4 ± 74.4, and 268.5 ± 73.2, respectively. The correlation coefficient between the number on the skin color scale and each index: M plus E, M, and E indices were 0.90, 0.90, and 0.86, respectively, with a statistical significance of P spectrophotometer.

Low-cost, digital lock-in module with external reference for coating glass transmission/reflection spectrophotometer

Science.gov (United States)

Alonso, R.; Villuendas, F.; Borja, J.; Barragán, L. A.; Salinas, I.

2003-05-01

A versatile, low-cost, digital signal processor (DSP) based lock-in module with external reference is described. This module is used to implement an industrial spectrophotometer for measuring spectral transmission and reflection of automotive and architectonic coating glasses over the ultraviolet, visible and near-infrared wavelength range. The light beams are modulated with an optical chopper. A digital phase-locked loop (DPLL) is used to lock the lock-in to the chop frequency. The lock-in rejects the ambient radiation and permits the spectrophotometer to work in the presence of ambient light. The algorithm that implements the dual lock-in and the DPLL in the DSP56002 evaluation module from Motorola is described. The use of a DSP allows implementation of the lock-in and DPLL by software, which gives flexibility and programmability to the system. Lock-in module cost, under 300 euro, is an important parameter taking into account that two modules are used in the system. Besides, the algorithms implemented in this DSP can be directly implemented in the latest DSP generations. The DPLL performance and the spectrophotometer are characterized. Capture and lock DPLL ranges have been measured and checked to be greater than the chop frequency drifts. The lock-in measured frequency response shows that the lock-in performs as theoretically predicted.

Automated atomic absorption spectrophotometer, utilizing a programmable desk calculator

International Nuclear Information System (INIS)

Futrell, T.L.; Morrow, R.W.

1977-01-01

A commercial, double-beam atomic absorption spectrophotometer has been interfaced with a sample changer and a Hewlett-Packard 9810A calculator to yield a completely automated analysis system. The interface electronics can be easily constructed and should be adaptable to any double-beam atomic absorption instrument. The calculator is easily programmed and can be used for general laboratory purposes when not operating the instrument. The automated system has been shown to perform very satisfactorily when operated unattended to analyze a large number of samples. Performance statistics agree well with a manually operated instrument

Simple LED spectrophotometer for analysis of color information.

Science.gov (United States)

Kim, Ji-Sun; Kim, A-Hee; Oh, Han-Byeol; Goh, Bong-Jun; Lee, Eun-Suk; Kim, Jun-Sik; Jung, Gu-In; Baek, Jin-Young; Jun, Jae-Hoon

2015-01-01

A spectrophotometer is the basic measuring equipment essential to most research activity fields requiring samples to be measured, such as physics, biotechnology and food engineering. This paper proposes a system that is able to detect sample concentration and color information by using LED and color sensor. Purity and wavelength information can be detected by CIE diagram, and the concentration can be estimated with purity information. This method is more economical and efficient than existing spectrophotometry, and can also be used by ordinary persons. This contribution is applicable to a number of fields because it can be used as a colorimeter to detect the wavelength and purity of samples.

Study of the influence of substrate and spectrophotometer characteristics on the in vitro measurement of sunscreens efficiency.

Science.gov (United States)

Couteau, C; Philippe, A; Vibet, M-A; Paparis, E; Coiffard, L

2018-05-16

All the methods used for the in vitro measurement of the SPF, the universal indicator of sunscreens efficiency, rely on a spectrophotometric analysis. What can vary about the experimental protocol used is mainly the substrate and the type of spectrophotometer chosen. We decided to work with polymethylmetacrylate plates that we analyzed using two spectrophotometers equipped with integrating spheres, the UV1000S and the UV2000 apparatus. Two marketed products were such tested, after spreading 2 mg/cm 2 on the plates, using one apparatus after another. We applied a non-parametric Wilcoxon test for paired data to the measures realized on 10 plates (as we systematically used the 2 apparatus), in order to compare the series of measures obtained with the two machines. This way, we were able to show a significant difference between the SPF values respectively obtained with the UV1000S and the UV2000 spectrophotometers. This difference could be explained by the decrease of the stray light in the case of the UV2000 apparatus. Copyright © 2017. Published by Elsevier B.V.

PMAS: The Potsdam Multi-Aperture Spectrophotometer. II. The Wide Integral Field Unit PPak

NARCIS (Netherlands)

Kelz, Andreas; Verheijen, Marc A. W.; Roth, Martin M.; Bauer, Svend M.; Becker, Thomas; Paschke, Jens; Popow, Emil; Sánchez, Sebastian F.; Laux, Uwe

2006-01-01

PPak is a new fiber-based integral field unit (IFU) developed at the Astrophysical Institute of Potsdam and implemented as a module into the existing Potsdam Multi-Aperture Spectrophotometer (PMAS) spectrograph. The purpose of PPak is to provide an extended field of view with a large

Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

Science.gov (United States)

Hanser, F. A.; Sellers, B.; Briehl, D. C.

1978-01-01

An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

Interference of different ionic species on the analysis of phosphate in HLW using spectrophotometer

International Nuclear Information System (INIS)

Mishra, P.K.; Ghongane, D.E.; Valsala, T.P.; Sonavane, M.S.; Kulkarni, Y.; Changrani, R.D.

2010-01-01

During reprocessing of spent nuclear fuel by PUREX process different categories of radioactive liquid wastes like High Level (HL), Intermediate Level (IL) and Low Level (LL) are generated. Different methodologies are adopted for management of these wastes. Since PUREX solvent (30% Tri butyl phosphate-70% Normal Paraffin Hydrocarbon) undergoes chemical degradation in the highly acidic medium of dissolver solution, presence of phosphate in the waste streams is inevitable. Since higher concentrations of phosphate in the HLW streams will affect its management by vitrification, knowledge about the concentration of phosphate in the waste is essential before finalising the glass composition. Since a large number of anionic and cationic species are present in the waste, these species may interfere phosphate analysis using spectrophotometer. In the present work, the interference of different anionic and cationic species on the analysis of phosphate in waste solutions using spectrophotometer was studied

Application of ZnO Nanoparticle as Sulphide Gas Sensor Using UV/VIS/NIR-Spectrophotometer

International Nuclear Information System (INIS)

Juliasih, N; Buchari; Noviandri, I

2017-01-01

The nanoparticle of metal oxides has great unique characteristics that applicable to the wide industrial as sensors and catalysts for reducing environmental pollution. Sulphide gas monitors and detectors are required for assessing safety aspects, due to its toxicity level. A thin film of ZnO as the sulphide gas sensor was synthesised by the simple method of chemical liquid deposition with variation of annealing temperature from 200 ºC to 500 ºC, and characterised by Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and UV/VIS/NIR-Spectrophotometer. Characterization studies showed nanoparticle size from the range 62 – 92 nm of diameters. The application this ZnO thin film to sulfide gas, detected by UV/VIS/NIR Spectrophotometer with diffuse reflectance, showed specific chemical reaction by the shifting of maximum % Reflectance peak. The gas sensing using this method is applicable at room. (paper)

Flameless atomic absorption determination of ruthenium using a ''Saturn-1'' spectrophotometer

International Nuclear Information System (INIS)

Pichkov, V.N.; Sinitsyn, N.M.; Sadikova, F.G.; Govorova, M.I.; Yakshinskij, A.I.

1980-01-01

A flameless atomic absorption method is suggested for determining ruthenium in samples of complicated composition using a ''Saturn-1'' spectrophotometer with a L'vov graphite cuvette. The method was used for determining ruthenium in a copper-based sample (10 -3 % Ru) and in electrolyte slurries (10 -3 -10 -2 %). The limit of detection Csub(min, 0.95) = 3.0x10 -3 μg Ru/ml. Other platinum metals do not interfere [ru

An Improved Flame Test for Qualitative Analysis Using a Multichannel UV-Visible Spectrophotometer

Science.gov (United States)

Blitz, Jonathan P.; Sheeran, Daniel J.; Becker, Thomas L.

2006-01-01

Qualitative analysis schemes are used in undergraduate laboratory settings as a way to introduce equilibrium concepts and logical thinking. The main component of all qualitative analysis schemes is a flame test, as the color of light emitted from certain elements is distinctive and a flame photometer or spectrophotometer in each laboratory is…

Laser-plasma sourced, temperature dependent, VUV spectrophotometer using dispersive analysis

International Nuclear Information System (INIS)

French, R.H.

1990-01-01

We have developed a vacuum ultraviolet spectrophotometer with wide energy and temperature range coverage, utilizing a laser-plasma light source (LPLS), CO 2 -laser sample heating and time-resolved dispersive analysis. Reflection and transmission spectra can be taken from 1.7 to 40 eV (31-700 nm) on samples at 15-1800 K with a time resolution of 20-400 ns. These capabilities permit the study of the temperature dependence of the electronic structure, encompassing the effects of thermal lattice expansion and electron-phonon interaction, and changes in the electronic structure associated with equilibrium and metastable phase transitions and stress relaxation. The LPLS utilizes a samarium laser-plasma created by a Q-switched Nd:YAG laser (500 mJ/pulse) to produce high brightness, stable, continuum radiation. The spectrophotometer is of a single beam design using calibrated iridium reference mirrors. White light is imaged off the sample in to the entrance slit of a 1-m polychromator. The resolution is 0.1 to 0.3 nm. The dispersed light is incident on a focal plane phosphor, fiber-optic-coupled to an image-intensified reticon detector. For spectroscopy between 300 and 1800 K, the samples are heated in situ with a 150 Watt CO 2 laser. The signal to noise ratio in the VUV, for samples at 1800 K, is excellent. From 300 K to 15 K samples are cooled using a He cryostat. (orig.)

Instrumentation-related uncertainty of reflectance and transmittance measurements with a two-channel spectrophotometer.

Science.gov (United States)

Peest, Christian; Schinke, Carsten; Brendel, Rolf; Schmidt, Jan; Bothe, Karsten

2017-01-01

Spectrophotometers are operated in numerous fields of science and industry for a variety of applications. In order to provide confidence for the measured data, analyzing the associated uncertainty is valuable. However, the uncertainty of the measurement results is often unknown or reduced to sample-related contributions. In this paper, we describe our approach for the systematic determination of the measurement uncertainty of the commercially available two-channel spectrophotometer Agilent Cary 5000 in accordance with the Guide to the expression of uncertainty in measurements. We focus on the instrumentation-related uncertainty contributions rather than the specific application and thus outline a general procedure which can be adapted for other instruments. Moreover, we discover a systematic signal deviation due to the inertia of the measurement amplifier and develop and apply a correction procedure. Thereby we increase the usable dynamic range of the instrument by more than one order of magnitude. We present methods for the quantification of the uncertainty contributions and combine them into an uncertainty budget for the device.

White light photothermal lens spectrophotometer for the determination of absorption in scattering samples.

Science.gov (United States)

Marcano, Aristides; Alvarado, Salvador; Meng, Junwei; Caballero, Daniel; Moares, Ernesto Marín; Edziah, Raymond

2014-01-01

We developed a pump-probe photothermal lens spectrophotometer that uses a broadband arc-lamp and a set of interference filters to provide tunable, nearly monochromatic radiation between 370 and 730 nm as the pump light source. This light is focused onto an absorbing sample, generating a photothermal lens of millimeter dimensions. A highly collimated monochromatic probe light from a low-power He-Ne laser interrogates the generated lens, yielding a photothermal signal proportional to the absorption of light. We measure the absorption spectra of scattering dye solutions using the device. We show that the spectra are not affected by the presence of scattering, confirming that the method only measures the absorption of light that results in generation of heat. By comparing the photothermal spectra with the usual absorption spectra determined using commercial transmission spectrophotometers, we estimate the quantum yield of scattering of the sample. We discuss applications of the device for spectroscopic characterization of samples such as blood and gold nanoparticles that exhibit a complex behavior upon interaction with light.

Repeatability in Color Measurements of a Spectrophotometer using Different Positioning Devices.

Science.gov (United States)

Hemming, Michael; Kwon, So Ran; Qian, Fang

2015-12-01

This study aimed to evaluate the repeatability of color measurements of an intraoral spectrophotometer with the use of three different methods by two operators. A total of 60 teeth were obtained, comprising 30 human maxillary teeth [central incisors (n = 10); canines (n = 10); molars (n = 10)] and 30 artificial teeth [lateral incisors (n = 10); premolar (n = 20)]. Multiple repeated color measurements were obtained from each tooth using three measuring methods by each of the two operators. Five typodonts with alternating artificial and human teeth were made. Measurements were taken by two operators with the Vita EasyShade spectrophotometer using the custom tray (CT), custom jig (CJ) and free hand (FH) method, twice, at an interval of 2 to 7 days. Friedman test was used to detect difference among the three color measuring methods. Post hoc Wilcoxon signed-rank test with Bonferroni correction applied was used for pair-wise comparison of color measurements among the three methods. Additionally, a paired-sample t-test was used to assess a significant difference between the two duplicated measurements made on the same tooth by the same operator for each color parameter and measuring method. For operator A, mean (SD) overall color change-ΔE* (SD) perceived for FH, CT and CJ were 2.21(2.00), 2.39 (1.58) and 2.86 (1.92), respectively. There was statistically significant difference in perceived ΔE* in FH vs CJ (p = 0.0107). However, there were no significant differences between FH and CT (p = 0.2829) or between CT and CJ (p = 0.1159). For operator B mean ΔE* (SD) for FH, CT and CJ were 3.24 (3.46), 1.95 (1.19) and 2.45 (1.56), respectively. There was a significant difference between FH and CT (p = 0.0031). However, there were no statistically significant differences in ΔE* in FH vs CJ (p = 0.3696) or CT vs CJ (p = 0.0809). The repeatability of color measurements was different among the three measuring methods by operators. Overall, the CT method worked well for both

Vertical-type chiroptical spectrophotometer (I): instrumentation and application to diffuse reflectance circular dichroism measurement.

Science.gov (United States)

Harada, Takunori; Hayakawa, Hiroshi; Kuroda, Reiko

2008-07-01

We have designed and built a novel universal chiroptical spectrophotometer (UCS-2: J-800KCMF), which can carry out in situ chirality measurement of solid samples without any pretreatment, in the UV-vis region and with high relative efficiency. The instrument was designed to carry out transmittance and diffuse reflectance (DR) circular dichroism (CD) measurements simultaneously, thus housing two photomultipliers. It has a unique feature that light impinges on samples vertically so that loose powders can be measured by placing them on a flat sample holder in an integrating sphere. As is our first universal chiroptical spectrophotometer, UCS-1, two lock-in amplifiers are installed to remove artifact signals arising from macroscopic anisotropies which are unique to solid samples. High performance was achieved by theoretically analyzing and experimentally proven the effect of the photoelastic modulator position on the CD base line shifts, and by selecting high-quality optical and electric components. Measurement of microcrystallines of both enantiomers of ammonium camphorsulfonate by the DRCD mode gave reasonable results.

[Design of flat field holographic concave grating for near-infrared spectrophotometer].

Science.gov (United States)

Xiang, Xian-Yi; Wen, Zhi-Yu

2008-07-01

Near-infrared spectrum analysis can be used to determine the nature or test quantitatively some chemical compositions by detecting molecular double frequency and multiple frequency absorption. It has been used in agriculture, biology, petrifaction, foodstuff, medicament, spinning and other fields. Near-infrared spectrophotometer is the main apparatus for near-infrared spectrum analysis, and the grating is the most important part of the apparatus. Based on holographic concave grating theory and optic design software CODE V, a flat field holographic concave grating for near-infrared spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. Using CODE V software, complex high-order aberration equations need not be solved, the result can be evaluated quickly, flat field and resolving power can be kept in balance, and the work efficiency is also enhanced. A paradigm of flat field holographic concave grating is given, it works between 900 nm to 1 700 nm, the diameter of the concave grating is 25 mm, and F/ # is 1. 5. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50 microm, is used to reconstruction, the theoretic resolution capacity is better than 6.3 nm.

Satisfaction of Dental Students, Faculty, and Patients with Tooth Shade-Matching Using a Spectrophotometer.

Science.gov (United States)

Ballard, Erin; Metz, Michael J; Harris, Bryan T; Metz, Cynthia J; Chou, Jang-Ching; Morton, Dean; Lin, Wei-Shao

2017-05-01

The aims of this study were to evaluate dental students' clinical shade-matching outcomes (from subjective use of shade guide) with an objective electronic shade-matching tool (spectrophotometer); to assess patients', students', and supervising faculty members' satisfaction with the clinical shade-matching outcomes; and to assess clinicians' support for use of the spectrophotometer to improve esthetic outcomes. A total of 103 volunteer groups, each consisting of patient, dental student, and supervising faculty member at the University of Louisville, were recruited to participate in the study in 2015. Using the spectrophotometer, clinical shade-matching outcome (ΔE clinical ) and laboratory shade-matching outcome (ΔE laboratory ) were calculated. Two five-point survey items were used to assess the groups' satisfaction with the clinical shade-matching outcome and support for an objective electronic shade-matching tool in the student clinic. The results showed that both ΔE clinical (6.5±2.4) and ΔE laboratory (4.3±2.0) were outside the clinical acceptability threshold ΔE values of 2.7, when visual shade-matching method (subjective usage of shade guide) was used to fabricate definitive restorations. Characteristics of the patients, dental students, supervising faculty members, and restorations had minimal to no effect on the ΔE clinical The patients, dental students, and supervising faculty members generally had positive opinions about the clinical shade-matching outcome, despite the increased ΔE clinical observed. Overall, clinical shade-matching outcomes in this school need further improvement, but the patients' positive opinions may indicate the need to revisit the acceptability threshold ΔE value of 2.7 in the academic setting.

A UV-Vis photoacoustic spectrophotometer.

Science.gov (United States)

Wiegand, Joseph R; Mathews, L Dalila; Smith, Geoffrey D

2014-06-17

A novel photoacoustic spectrophotometer (PAS) for the measurement of gas-phase and aerosol absorption over the UV-visible region of the spectrum is described. Light from a broadband Hg arc lamp is filtered in eight separate bands from 300 to 700 nm using bandpass interference filters (centered at 301 nm, 314 nm, 364 nm, 405 nm, 436 nm, 546 nm, 578 and 687 nm) and modulated with an optical chopper before entering the photoacoustic cell. All wavelength bands feature a 20-s detection limit of better than 3.0 Mm(-1) with the exception of the lower-intensity 687 nm band for which it is 10.2 Mm(-1). Validation measurements of gas-phase acetone and nigrosin aerosol absorption cross sections at several wavelengths demonstrate agreement to within 10% with those measured previously (for acetone) and those predicted by Mie theory (for nigrosin). The PAS instrument is used to measure the UV-visible absorption spectrum of ambient aerosol demonstrating a dramatic increase in the UV region with absorption increasing by 300% from 405 to 301 nm. This type of measurement throughout the UV-visible region and free from artifacts associated with filter-based methods has not been possible previously, and we demonstrate its promise for classifying and quantifying different types of light-absorbing ambient particles.

Near-IR laser-based spectrophotometer for comparative analysis of isotope content of CO2 in exhale air samples

International Nuclear Information System (INIS)

Stepanov, E V; Glushko, A N; Kasoev, S G; Koval', A V; Lapshin, D A

2011-01-01

We present a laser spectrophotometer aimed at high-accuracy comparative analysis of content of 12 CO 2 and 13 CO 2 isotope modifications in the exhale air samples and based on a tunable near-IR diode laser (2.05 μm). The two-channel optical scheme of the spectrophotometer and the special digital system for its control are described. An algorithm of spectral data processing aimed at determining the difference in the isotope composition of gas mixtures is proposed. A few spectral regions (near 4880 cm -1 ) are determined to be optimal for analysis of relative content of 12 CO 2 and 13 CO 2 in the exhale air. The use of the proposed spectrophotometer scheme and the developed algorithm makes the results of the analysis less susceptible to the influence of the interference in optical elements, to the absorption in the open atmosphere, to the slow drift of the laser pulse envelope, and to the offset of optical channels. The sensitivity of the comparative analysis of the isotope content of CO 2 in exhale air samples, achieved using the proposed scheme, is estimated to be nearly 0.1‰.

X-ray spectrophotometer SphinX and particle spectrometer STEP-F of the satellite experiment CORONAS-PHOTON. Preliminary results of the joint data analysis

Science.gov (United States)

Dudnik, O. V.; Podgorski, P.; Sylwester, J.; Gburek, S.; Kowalinski, M.; Siarkowski, M.; Plocieniak, S.; Bakala, J.

2012-04-01

A joint analysis is carried out of data obtained with the help of the solar X-ray SphinX spectrophotometer and the electron and proton satellite telescope STEP-F in May 2009 in the course of the scientific space experiment CORONAS-PHOTON. In order to determine the energies and particle types, in the analysis of spectrophotometer records data are used on the intensities of electrons, protons, and secondary γ-radiation, obtained by the STEP-F telescope, which was located in close proximity to the SphinX spectrophotometer. The identical reaction of both instruments is noted at the intersection of regions of the Brazilian magnetic anomaly and the Earth's radiation belts. It is shown that large area photodiodes, serving as sensors of the X-ray spectrometer, reliably record electron fluxes of low and intermediate energies, as well as fluxes of the secondary gamma radiation from construction materials of detector modules, the TESIS instrument complex, and the spacecraft itself. The dynamics of electron fluxes, recorded by the SphinX spectrophotometer in the vicinity of a weak geomagnetic storm, supplements the information about the processes of radial diffusion of electrons, which was studied using the STEP-F telescope.

PC based data system for infrared spectrophotometer PU-9512

International Nuclear Information System (INIS)

Ali, Mohd Yakub; Venkiteswaran, S.; Nagar, M.S.

2000-08-01

This report summarises the upgrading of an old Infra Red Spectrophotometer using a pc for control, data acquisition, storage and analysis. The hardware link is made through RS232C serial port. The control and data management is achieved through software. A brief account of the facilities provided and versatility of the analysis package which was developed in-house in a user friendly menu driven fashion is given here. This is supported by the analysis and inter comparison of infra red spectra of organic/inorganic reactants and products. It has specific application in synthesis and characterization of new extractants, solvents, actinide and lanthanide complexes and in the study of thermally and radiolytically degraded products. (author)

Estimation of total alkaloid in Chitrakadivati by UV-Spectrophotometer.

Science.gov (United States)

Ajanal, Manjunath; Gundkalle, Mahadev B; Nayak, Shradda U

2012-04-01

Herbal formulation standardization by adopting newer technique is need of the hour in the field of Ayurvedic pharmaceutical industry. As very few reports exist. These kind of studies would certainly widen the herbal research area. Chitrakadivati is one such popular herbal formulation used in Ayurveda. Many of its ingredients are known for presence of alkaloids. Presence of alkaloid was tested qualitatively by Dragondroff's method then subjected to quantitative estimation by UV-Spectrophotometer. This method is based on the reaction between alkaloid and bromocresol green (BCG). Study discloses that out of 16 ingredients, 9 contain alkaloid. Chitrakadivati has shown 0.16% of concentration of alkaloid and which is significantly higher than it's individual ingredients.

Image plane detector spectrophotometer - Application to O2 atmospheric band nightglow

Science.gov (United States)

Luo, Mingzhao; Yee, Jeng-Hwa; Hays, Paul B.

1988-01-01

A new variety of low resolution spectrometer is described. This device, an image plane detector spectrophotometer, has high sensitivity and modest resolution sufficient to determine the rotational temperature and brightness of molecular band emissions. It uses an interference filter as a dispersive element and a multichannel image plane detector as the photon collecting device. The data analysis technqiue used to recover the temperature of the emitter and the emission brightness is presented. The atmospheric band of molecular oxygen is used to illustrate the use of the device.

Construction, calibration, and application of a compact spectrophotometer for EUV(300-2500 A) plasma diagnostics

International Nuclear Information System (INIS)

Moos, H.W.; Chen, K.I.; Terry, J.L.

1979-01-01

A 400-mm normal incidence concave grating spectrophotometer, specifically designed for plasma diagnostics, is described. The wavelength drive, in which the grating is translated as well as rotated, is discussed in detail; the wavelength linearity of the sine drive and methods of improving it are analyzed. The instrument can be used in any orientation, is portable under vacuum, and quite rugged. The construction techniques utilized produce a high quality vacuum making the instrument compatible with both high purity plasma devices and synchrotron radiation sources. The photometric sensitivity calibration was found to be very stable during extended use on high temperature plasma devices. The applications of the instrument to diagnose plasmas in two tokamaks and a mirror device are decribed. A facility used for photometric calibration of extreme ultraviolet (lambda>300-A) spectrophotometers against NBS standard diodes is described. The instrumental calibration obtained using this facility was checked by using synchrotron radiation from SURF II; very good agreement was observed

Differences between the human eye and the spectrophotometer in the shade matching of tooth colour.

Science.gov (United States)

Gómez-Polo, Cristina; Gómez-Polo, Miguel; Celemin-Viñuela, Alicia; Martínez Vázquez De Parga, Juan Antonio

2014-06-01

The aim of this work was to assess the agreement between instrumental and visual colour matching. Shade selection with the 3DMaster Toothguide (Vita-Zahnfabrik) was performed for 1361 maxillary central incisors and compared with the shade obtained with the EasyShade Compact (Vita-Zahnfabrik) spectrophotometer. We observed a greater correlation between the objective method and the subjective one in the colour dimension of lightness (Kappa 0.6587), followed by hue (Kappa 0.4337) and finally chroma (Kappa 0.3578). The colour dimension in which the greatest agreement is seen between the operator and the spectrophotometer is value or lightness. This study reveals differences between the measurement of colour via spectrophotometry and the visual shade selection method. According to our results, there is better agreement in the value or lightness colour dimension, which is the most important one in the choice of tooth colour. Copyright © 2014 Elsevier Ltd. All rights reserved.

AESoP: Astronomical Extinction Spectrophotometer

Science.gov (United States)

Linford, Justin; McGraw, J.; Zimmer, P.; Ackermann, M.; Fitch, J.

2009-01-01

The Earth's atmosphere is a major obstruction to the precision and accuracy of ground-based photometry. The atmosphere removes light from astronomical objects both by absorption and scattering by constituent molecules, aerosols and clouds. These effects can change significantly over short time periods and over modest angles on the sky. To further understand these effects, the UNM Measurement Astrophysics Group has designed, built and recently deployed the Astronomical Extinction Spectrophotometer (AESoP), a 100mm objective grating spectrometer. By monitoring bright stars in sensibly the same direction as a larger photometric telescope is observing, AESoP will measure the wavelength-dependent extinction due to the Earth's atmosphere from 450nm to 900nm on time scales of approximately one minute. The collocated Astronomical LIDAR for Extinction (ALE) provides a high-precision monochromatic extinction measurement at 527nm. Knowing the extinction at a single wavelength allows us to pin the relative spectra generated by AESoP. These extinction spectra can then be integrated over the bandpass of the photometric telescope system to create real time corrections of observations. We present the design and construction of AESoP along with the preliminary results of our first combined observing campaign. This effort is our first step toward breaking the 1% photometry barrier. This project is funded by AFRL Grant FA9451-04-2-0355

Development of a new reference spectrophotometer

International Nuclear Information System (INIS)

Zwinkels, J.C.; Gignac, D.S.

1989-01-01

A new reference spectrophotometer is being developed at the National Research Council of Canada (NRCC) for high-accuracy transmittance measurements over the spectral range 200 to 250 nm. This computerized instrument is a single-beam design based upon a servomotor-driven double monochromator with a wavelength resolution of 0.022 nm. The other main components are: two interchangeable sources (deuterium and tungsten-halogen), two computer-selectable TE-cooled detectors (GaAs photomultiplier tube and PbS cell), all-reflective input and exit optics, and a large sample compartment. The significant feature of the optical system is a large, well-collimated measurement beam: the angle of convergence is 0.7 degrees for a slit height of 7 mm, and the maximal beam size is 37 x 20 mm. This beam geometry eliminates the need for polarization corrections (using linearly polarized light) or compensation for spatially non-uniform detector responsivity (using averaging sphere). The paper describes the instrument design and presents data from preliminary performance tests. The systematic and random sources of error that have been investigated include: wavelength accuracy and reproducibility, bandpass, beam uniformity, polarization, stray light, system drift and linearity

Determining the Absorbance Spectra of Photochromic Materials From Measured Spectrophotometer Data

Science.gov (United States)

Downie, John D.

1998-01-01

If a two-state photochromic material is optically bleached, the absorbance spectrum data measured by a spectrophotometer is in general comprised of components from both the ground state and the upper state. Under general conditions, it may be difficult to extract the actual upper state spectrum from the spectrum of the bleached material. A simple algorithm is presented here for the recovery of the pure absorbance spectra of the upper state of a material such as bacteriorhodopsin, given single wavelength bleaching illumination, steady-state conditions, and accurate knowledge of phototransition rates and thermal decay rates.

Information-measurement and control system of the five-channel stellar spectrophotometer

International Nuclear Information System (INIS)

Granitskij, L.V.; Bukach, A.B.; Kaplin, Yu.V.; Bondarenko, V.P.; Smirnov, A.I.

1979-01-01

The multichannel information-measurement control system of the five-channel stellar spectrophotometer working in photon counting regime is described. The detecting part is synthesized taking into account the principles of multifunctional use of elements of the system. In the part of the photometer scanning mechanism control a discrete drive with the step motor is used. The data are detected on the punched tape, which is convenient for putting them into computer, into a digit printing device with the decimal code or on a diagram tape of the automatic potentiometer

A broad band X-ray imaging spectrophotometer for astrophysical studies

Science.gov (United States)

Lum, Kenneth S. K.; Lee, Dong Hwan; Ku, William H.-M.

1988-01-01

A broadband X-ray imaging spectrophotometer (BBXRIS) has been built for astrophysical studies. The BBXRIS is based on a large-imaging gas scintillation proportional counter (LIGSPC), a combination of a gas scintillation proportional counter and a multiwire proportional counter, which achieves 8 percent (FWHM) energy resolution and 1.5-mm (FWHM) spatial resolution at 5.9 keV. The LIGSPC can be integrated with a grazing incidence mirror and a coded aperture mask to provide imaging over a broad range of X-ray energies. The results of tests involving the LIGSPC and a coded aperture mask are presented, and possible applications of the BBXRIS are discussed.

Interexaminer reliability in clinical measurement of L*C*h* values of anterior teeth using a spectrophotometer.

Science.gov (United States)

Hassel, Alexander J; Grossmann, Anne-christiane; Schmitter, Marc; Balke, Zibandeh; Buzello, Anja M

2007-01-01

The objective of this study was to investigate interexaminer reliability in the clinical measurement of the L*C*h* (lightness/value, chroma, hue) values of anterior teeth using a spectrophotometer (Vita Easyshade). The basic color of the maxillary right central incisors and canines of 23 subjects was spectrophotometrically determined by 4 clinicians and an experienced user (development manager) of the spectrophotometer. Also, to analyze the effect of different training with the instrument on interexaminer reliability, 2 of the clinicians were instructed in the use of the spectrophotometer by the experienced examiner, whereas the others instructed themselves by studying the operating manual. Agreement between all examiners was acceptable to excellent (intraclass coefficient > 0.4). The mean value of the measured differences for the central incisors of all subjects for L* values was 5 (for C* = 3.8, h* = 2.7 degrees) and for canines, the mean L* was 4.5 (C* = 3, h* = 1.6 degrees). Results from comparison of the 2 different training methods were inconsistent. Agreement with the experienced examiner ranged from not acceptable (C* values for incisors of self-instructed examiners) to excellent. The distribution of the measurements of 1 subject could lead to deviations in color, probably with clinical impact. For canines, the measurements were at least equally reproducible (in some cases significantly more reproducible) compared to central incisors. Because of the small number of examiners and the inconsistent results, it was not possible to reach a definite conclusion about the effect of different training methods on interexaminer reliability.

Data acquisition system and performance based on Apple II for using in experimental physics - Applications to spectrophotometer

International Nuclear Information System (INIS)

Costa, L.F.; Castro, J.C.

1987-01-01

A microcomputer based system oriented to experimental physics is described. The system was developed to achieve versatility, low cost, reliability and easy utilization. An application to this system to a dispersive spectrophotometer is also included. (author) [pt

Non-invasive prediction of hematocrit levels by portable visible and near-infrared spectrophotometer.

Science.gov (United States)

Sakudo, Akikazu; Kato, Yukiko Hakariya; Kuratsune, Hirohiko; Ikuta, Kazuyoshi

2009-10-01

After blood donation, in some individuals having polycythemia, dehydration causes anemia. Although the hematocrit (Ht) level is closely related to anemia, the current method of measuring Ht is performed after blood drawing. Furthermore, the monitoring of Ht levels contributes to a healthy life. Therefore, a non-invasive test for Ht is warranted for the safe donation of blood and good quality of life. A non-invasive procedure for the prediction of hematocrit levels was developed on the basis of a chemometric analysis of visible and near-infrared (Vis-NIR) spectra of the thumbs using portable spectrophotometer. Transmittance spectra in the 600- to 1100-nm region from thumbs of Japanese volunteers were subjected to a partial least squares regression (PLSR) analysis and leave-out cross-validation to develop chemometric models for predicting Ht levels. Ht levels of masked samples predicted by this model from Vis-NIR spectra provided a coefficient of determination in prediction of 0.6349 with a standard error of prediction of 3.704% and a detection limit in prediction of 17.14%, indicating that the model is applicable for normal and abnormal value in Ht level. These results suggest portable Vis-NIR spectrophotometer to have potential for the non-invasive measurement of Ht levels with a combination of PLSR analysis.

Development of optical spectrum acquisition with spectrophotometer for characterization of optical radiation sources

International Nuclear Information System (INIS)

Solano Vargas, Alvaro

2013-01-01

An improved process of the data acquisition system is developed with Pasco 750 interface and Pasco OS-8539 spectrophotometer. The optical spectrum and color temperature of incandescent sources available are obtained from the Laboratorio de Fotonica y Tecnologia Laser Aplicada. The procedures developed in the project are recommended to collect data and analyze results. The purchase of a new Software and the interface of Pasco is recommended to have a better operation and update [es

Objectification of facial color inspection to differentiate obstructive/nonobstructive jaundice in neonates by spectrophotometer.

Science.gov (United States)

Shen, Zhen; Zheng, Shan; Dong, Rui; Chen, Gong

2017-12-01

The purpose of this study was to study whether color difference in facial color truly exists between neonates with obstructive and nonobstructive jaundice, and whether the color difference could be objectified by spectrophotometer. Twelve biliary atresia patients were enrolled in an obstructive jaundice group and 15 neonates admitted for non-conjugated hyperbilirubinemia in a nonobstructive group. Nine patients with syphilis (n=6) and sacrococcygeal teratoma (n=3) were studied as control. Transcutaneous total bilirubin (TB) and hemoglobin were recorded. Face color was measured by spectrophotometer. Spectral reflection curve and L*a*b* model parameters were studied. Facial color of jaundiced neonates were characteristic in waveform that reflectivity at wavelength of 550nm was significantly decreased compared with control by 16.4±3.4%, while not significantly different between obstructive and nonobstructive jaundice (p=0.124). At 650nm, reflection in nonobstructive jaundice was decreased by 8.4±2.3% (pobstructive jaundice (58.09±1.25%)>nonobstructive jaundice (54.25±7.27%). Value b* was higher in jaundiced patients compared to normal control (11.88±2.16, pspectrophotometer. Study of Diagnostic Test. Level II. Copyright © 2017 Elsevier Inc. All rights reserved.

A method for calibration of Soleil-Babinet compensator using a spectrophotometer

Science.gov (United States)

Wang, Jun; Chen, Lei; Li, Bo; Shi, Lili; Luo, Ting

2010-06-01

A method using a spectrophotometer for calibrating Soleil-Babinet compensator is proposed. It is based on the spectroscopic method which utilizes the relation between transmittance and wavelength to obtain retardation. By placing a multiple order half wave plate behind the Soleil-Babinet compensator, zero-order retardation can be measured, which is difficult to accomplish by spectroscopic method. In the experiment, the retardations of the compensator in the range 0- λ are measured. It is demonstrated that the precision of retardation is 0.45 nm at the position 0 and λ while the maximum error is less than 1 nm between the two positions.

RECALIBRATION OF H CANYON ONLINE SPECTROPHOTOMETER AT EXTENDED URANIUM CONCENTRATION

International Nuclear Information System (INIS)

Lascola, R

2008-01-01

The H Canyon online spectrophotometers are calibrated for measurement of the uranium and nitric acid concentrations of several tanks in the 2nd Uranium Cycle.[1] The spectrometers, flow cells, and prediction models are currently optimized for a process in which uranium concentrations are expected to range from 0-15 g/L and nitric acid concentrations from 0.05-6 M. However, an upcoming processing campaign will involve 'Super Kukla' material, which has a lower than usual enrichment of fissionable uranium. Total uranium concentrations will be higher, spanning approximately 0-30 g/L U, with no change in the nitric acid concentrations. The new processing conditions require the installation of new flow cells with shorter path lengths. As the process solutions have a higher uranium concentration, the shorter path length is required to decrease the absorptivity to values closer to the optimal range for the instrument. Also, new uranium and nitric acid prediction models are required to span the extended uranium concentration range. The models will be developed for the 17.5 and 15.4 tanks, for which nitric acid concentrations will not exceed 1 M. The restricted acid range compared to the original models is anticipated to reduce the measurement uncertainty for both uranium and nitric acid. The online spectrophotometers in H Canyon Second Uranium Cycle were modified to allow measurement of uranium and nitric acid for the Super Kukla processing campaign. The expected uranium concentrations, which are higher than those that have been recently processed, required new flow cells with one-third the optical path length of the existing cells. Also, new uranium and nitric acid calibrations were made. The estimated reading uncertainties (2σ) for Tanks 15.4 and 17.5 are ∼5% for uranium and ∼25% for nitric acid

Photochemical induced growth and aggregation of metal nanoparticles in diode-array spectrophotometer via excited dimethyl-sulfoxide.

Science.gov (United States)

Zidki, Tomer; Cohen, Haim; Meyerstein, Dan

2010-10-21

Ag(0) and Au(0) nanoparticles suspended in dilute aqueous solutions containing (CH(3))(2)SO are photochemically unstable. The light source of a diode-array spectrophotometer induces, within less than a minute, particle growth and aggregation. The results indicate that this process is triggered by UV light absorption by the (CH(3))(2)SO.

Development of a low-cost NIR instrument for minced meat analysis: Part 1 - Spectrophotometer and sample presentations

Science.gov (United States)

The feasibility of using a compact, low-cost NIR spectrophotometer to predict moisture (MC) and total fat content of minced pork was demonstrated. Results were compared with those obtained using two research type instruments with high signal to noise ratio (S/N). The NIR measuring head of the compac...

A furnace and temperature controller for optical absorption studies with a spectrophotometer

International Nuclear Information System (INIS)

Mariani Rogat, F.

1975-01-01

The design and main features of a furnace with a temperature controller and programmer are shown. This system allows to measure the optical absorption spectrum of a sample from room temperature to 400 deg C, in a double beam spectrophotometer Perkin Elmer 350. The sample temperature can be linearly increased at different heating rates between 4 and 38 deg C/min. The temperature ramp can be stopped at any desired point and the sample temperature shall be stabilized in less than one minute. This temperature shall be kept constant within 0.5 deg C for hours. The sample is heated in vacuum. (author)

Sensitivity of digital dental photo CIE L*a*b* analysis compared to spectrophotometer clinical assessments over 6 months.

Science.gov (United States)

Sluzker, Ariel; Knösel, Michael; Athanasiou, Athanasios E

2011-10-01

To assess the sensitivity of digital dental photo CIE L*a*b* analysis compared to clinical spectrophotometer assessments over 6 months. CIE L*a*b* values for the upper right central incisors of 14 predoctoral dental students subjected to certain color-relevant exclusion criteria were recorded at baseline (T0), after 6 months (T1), and 1 week later (T2), using (Method 1) a spectrophotometer and (Method 2) a method of digital photo analysis. Statistical analysis of color and lightness data between both methods and time points were assessed using the Shapiro-Wilk test, Pearson's correlation coefficient (r), Dahlberg's formula for method error calculation, and paired samples t-tests, adopting a level of significance alpha = 0.05. Between T0 - T1, the spectrophotometer recorded significant changes in lightness (75.51 > 77.75) and color values (a*: 3.25 > 2.38; b*: 18.47 > 17.31), whereas significant changes with Method 2 were only seen for b* (21.51 > 20.57). No significant changes for overall color and lightness changes deltaE to deltaE2 were found for either of the methods. The error of the method (T1-T2) and corresponding correlation coefficients r for values L*a*b* were found to be 1.44 / 0.43 / 0.62 (r: 0.69; P = 0.007/0.64; P = 0.14/0.9; P < 0.001) for Method 1 and 0.97/0.67/1.25 (r : 0.87; P < 0.001/0.63; P = 0.17/0.57, P = 0.04) for Method 2, respectively.

Early results from the Far Infrared Absolute Spectrophotometer (FIRAS)

Science.gov (United States)

Mather, J. C.; Cheng, E. S.; Shafer, R. A.; Eplee, R. E.; Isaacman, R. B.; Fixsen, D. J.; Read, S. M.; Meyer, S. S.; Weiss, R.; Wright, E. L.

1991-01-01

The Far Infrared Absolute Spectrophotometer (FIRAS) on the Cosmic Background Explorer (COBE) mapped 98 percent of the sky, 60 percent of it twice, before the liquid helium coolant was exhausted. The FIRAS covers the frequency region from 1 to 100/cm with a 7 deg angular resolution. The spectral resolution is 0.2/cm for frequencies less than 20/cm and 0.8/cm for higher frequencies. Preliminary results include: a limit on the deviations from a Planck curve of 1 percent of the peak brightness from 1 to 20/cm, a temperature of 2.735 +/- 0.06 K, a limit on the Comptonization parameter y of 0.001, on the chemical potential parameter mu of 0.01, a strong limit on the existence of a hot smooth intergalactic medium, and a confirmation that the dipole anisotropy spectrum is that of a Doppler shifted blackbody.

Agreement between digital image analysis and clinical spectrophotometer in CIEL*C*h° coordinate differences and total color difference (ΔE) measurements of dental ceramic shade tabs.

Science.gov (United States)

Farah, Ra'fat I

2016-01-01

The objectives of this in vitro study were: 1) to test the agreement among color coordinate differences and total color difference (ΔL*, ΔC*, Δh°, and ΔE) measurements obtained by digital image analysis (DIA) and spectrophotometer, and 2) to test the reliability of each method for obtaining color differences. A digital camera was used to record standardized images of each of the 15 shade tabs from the IPS e.max shade guide placed edge-to-edge in a phantom head with a reference shade tab. The images were analyzed using image-editing software (Adobe Photoshop) to obtain the color differences between the middle area of each test shade tab and the corresponding area of the reference tab. The color differences for the same shade tab areas were also measured using a spectrophotometer. To assess the reliability, measurements for the 15 shade tabs were repeated twice using the two methods. The Intraclass Correlation Coefficient (ICC) and the Dahlberg index were used to calculate agreement and reliability. The total agreement of the two methods for measuring ΔL*, ΔC*, Δh°, and ΔE, according to the ICC, exceeded 0.82. The Dahlberg indices for ΔL* and ΔE were 2.18 and 2.98, respectively. For the reliability calculation, the ICCs for the DIA and the spectrophotometer ΔE were 0.91 and 0.94, respectively. High agreement was obtained between the DIA and spectrophotometer results for the ΔL*, ΔC*, Δh°, and ΔE measurements. Further, the reliability of the measurements for the spectrophotometer was slightly higher than the reliability of all measurements in the DIA.

SphinX soft X-ray spectrophotometer: Science objectives, design and performance

Science.gov (United States)

Gburek, S.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Kordylewski, Z.; Podgorski, P.; Plocieniak, S.; Siarkowski, M.; Sylwester, B.; Trzebinski, W.; Kuzin, S. V.; Pertsov, A. A.; Kotov, Yu. D.; Farnik, F.; Reale, F.; Phillips, K. J. H.

2011-06-01

The goals and construction details of a new design Polish-led X-ray spectrophotometer are described. The instrument is aimed to observe emission from entire solar corona and is placed as a separate block within the Russian TESIS X- and EUV complex aboard the CORONAS-PHOTON solar orbiting observatory. SphinX uses silicon PIN diode detectors for high time resolution measurements of the solar spectra in the range 0.8-15 keV. Its spectral resolution allows for discerning more than hundred separate energy bands in this range. The instrument dynamic range extends two orders of magnitude below and above these representative for GOES. The relative and absolute accuracy of spectral measurements is expected to be better than few percent, as follows from extensive ground laboratory calibrations.

Flight of a UV spectrophotometer aboard Galileo 2, the NASA Convair 990 aircraft

Science.gov (United States)

Sellers, B.; Hunderwadel, J. L.; Hanser, F. A.

1976-01-01

An ultraviolet interference-filter spectrophotometer (UVS) fabricated for aircraft-borne use on the DOT Climatic Impact Assessment Program (CIAP) has been successfully tested in a series of flights on the NASA Convair 990, Galileo II. UV flux data and the calculated total ozone above the flight path are reported for several of the flights. Good agreement is obtained with the total ozone as deducted by integration of an ozone sonde vertical profile obtained at Wallops Island, Virginia near the time of a CV-990 underpass. Possible advantages of use of the UVS in the NASA Global Atmospheric Sampling Program are discussed.

Quantification of dsDNA using the Hitachi F-7000 Fluorescence Spectrophotometer and PicoGreen dye.

Science.gov (United States)

Moreno, Luis A; Cox, Kendra L

2010-11-05

Quantification of DNA, especially in small concentrations, is an important task with a wide range of biological applications including standard molecular biology assays such as synthesis and purification of DNA, diagnostic applications such as quantification of DNA amplification products, and detection of DNA molecules in drug preparations. During this video we will demonstrate the capability of the Hitachi F-7000 Fluorescence Spectrophotometer equipped with a Micro Plate Reader accessory to perform dsDNA quantification using Molecular Probes Quant-it PicoGreen dye reagent kit. The F-7000 Fluorescence Spectrophotometer offers high sensitivity and high speed measurements. It is a highly flexible system capable of measuring fluorescence, luminescence, and phosphorescence. Several measuring modes are available, including wavelength scan, time scan, photometry and 3-D scan measurement. The spectrophotometer has sensitivity in the range of 50 picomoles of fluorescein when using a 300 μL sample volume in the microplate, and is capable of measuring scan speeds of 60,000 nm/minute. It also has a wide dynamic range of up to 5 orders of magnitude which allows for the use of calibration curves over a wide range of concentrations. The optical system uses all reflective optics for maximum energy and sensitivity. The standard wavelength range is 200 to 750 nm, and can be extended to 900 nm when using one of the optional near infrared photomultipliers. The system allows optional temperature control for the plate reader from 5 to 60 degrees Celsius using an optional external temperature controlled liquid circulator. The microplate reader allows for the use of 96 well microplates, and the measuring speed for 96 wells is less than 60 seconds when using the kinetics mode. Software controls for the F-7000 and Microplate Reader are also highly flexible. Samples may be set in either column or row formats, and any combination of wells may be chosen for sample measurements. This allows

[Precision and accuracy of a dental spectrophotometer in gingival color measurement of maxillary anterior gingival].

Science.gov (United States)

Du, Yang; Tan, Jian-guo; Chen, Li; Wang, Fang-ping; Tan, Yao; Zhou, Jian-feng

2012-08-18

To explore a gingival shade matching method and to evaluate the precision and accuracy of a dental spectrophotometer modified to be used in gingival color measurement. Crystaleye, a dental spectrophotometer (Olympus, Tokyo, Japan) with a custom shading cover was tested. For precision assessment, two experienced experimenters measured anterior maxillary incisors five times for each tooth. A total of 20 healthy gingival sites (attached gingiva, free gingiva and medial gingival papilla in anterior maxillary region) were measured,the Commission Internationale de I' Eclairage (CIE) color parameters (CIE L*a*b*) of which were analyzed using the supporting software. For accuracy assessment, a rectangular area of approximately 3 mm×3 mm was chosen in the attached gingival portion for spectral analysis. PR715 (SpectraScan;Photo Research Inc.,California, USA), a spectroradiometer, was utilized as standard control. Average color differences (ΔE) between the values from PR715 and Crystaleye were calculated. In precision assessment,ΔL* between the values in all the test sites and average values were from(0.28±0.16)to(0.78±0.57), with Δa*and Δb* from(0.28±0.15)to (0.87±0.65),from(0.19±0.09)to( 0.58±0.78), respectively. Average ΔE between values in all test sites and average values were from (0.62 ± 0.17) to (1.25 ± 0.98) CIELAB units, with a total average ΔE(0.90 ± 0.18). In accuracy assessment, ΔL* with control device were from(0.58±0.50)to(2.22±1.89),with Δa*and Δb* from(1.03±0.67)to(2.99±1.32),from(0.68±0.78)to(1.26±0.83), respectively. Average ΔE with the control device were from (2.44±0.82) to (3.51±1.03) CIELAB units, with a total average ΔE (2.96 ± 1.08). With appropriate modification, Crystaleye, the spectrophotometer, has demonstrated relative minor color variations that can be useful in gingival color measurement.

Assessing the Engagement, Learning, and Overall Experience of Students Operating an Atomic Absorption Spectrophotometer with Remote Access Technology

Science.gov (United States)

Erasmus, Daniel J.; Brewer, Sharon E.; Cinel, Bruno

2015-01-01

The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of…

Evaluation of the LASL automated spectrophotometer for uranium determination at submilligram levels

International Nuclear Information System (INIS)

Hollen, R.M.; Jackson, D.D.; Rein, J.E.

1977-07-01

The LASL automated spectrophotometer, designed for determination of 1 to 14 mg of uranium and 0.5 to 14 mg of plutonium, has been evaluated for determination of lower levels of uranium to 0.12 mg. The essentially linear response of absorbance is maintained and the standard deviation for a single measurement is constant at about 0.013 mg of uranium, corresponding to a maximum uncertainty of about 10 percent at the 0.12-mg limit. The instrument was applied to the analysis of a series of low-level-concentration, 0.07- to 0.8-mg/ml uranium samples. The results were not statistically different from those obtained by a manual spectrophotometric method

A Study of UV Spectral Transmission Through Different Transparent Media with Spectrophotometer

Directory of Open Access Journals (Sweden)

R B Gadgil

1981-01-01

Full Text Available This experiment was carried out with the help of spectrophotometer using an artificial UV light source to find -out the percentage transmission of UVA and UVB regions of the UV spectrum. The aim of the experiment was to select the transparent medium which would block mum UVB at the same time allowing mammum UVA to pass through thus reducing the unwanted side effects of UVB light and reducing the efficacy of PUVASOL. It was observed that an ordinary plain 3.3 mm colorless glass was the best transparent medium and with its use a simple solarium could be constructed to treat patients on PUVASOL with sunlight as the source of UV light.

Demonstrating Principles of Spectrophotometry by Constructing a Simple, Low-Cost, Functional Spectrophotometer Utilizing the Light Sensor on a Smartphone

Science.gov (United States)

Hosker, Bill S.

2018-01-01

A highly simplified variation on the do-it-yourself spectrophotometer using a smartphone's light sensor as a detector and an app to calculate and display absorbance values was constructed and tested. This simple version requires no need for electronic components or postmeasurement spectral analysis. Calibration graphs constructed from two…

Spectrophotometer as a tool for analysis of various species in radioactive liquid wastes (Preprint No. RA-27)

International Nuclear Information System (INIS)

Yeotikar, R.G.; Kaushik, C.P.; Raj, Kanwar

1988-02-01

For the immobilisation of high level radioactive liquid waste in a glass matrix, the analysis of different species in the waste is the primary requirement for fixing the base composition of glass. The commercially available spectrophotometer has been remotised to facilitate the analysis of different radioactive streams. Methods for analysis of constituents such as Fe, Mo, Cr, U, total lanthanides, Zr and PO4 have been established. (author)

Evaluation of Biocompatibility of Root Canal Sealers on L929 Fibroblasts with Multiscan EX Spectrophotometer.

Science.gov (United States)

Konjhodzic-Prcic, Alma; Jakupovic, Selma; Hasic-Brankovic, Lajla; Vukovic, Amra

2015-06-01

The purpose of the current study was to estimate the biocompatibility of endodontic sealers with different bases on L929 mouse fibroblasts permanent cell line using Multiscan EX Spectrophotometer. Endodontics sealers used in this study were GuttaFlow (Roeko) silicone based sealer, AH plus (De Tray-DENTSPLY) epoxy resin based, Apexit (Vivadent) calcium hydroxide based and Endorez (Ultradent) methacrylate based sealer. Sealer were tested trough time, freshly mixed 24 h, 48h and 7 days after setting. Biocompatibility was determinate on permanent cell lines L929 mouse fibroblasts trough cytotoxicity using MTT assay. Level of absorption was measured with multi scan EX spectrophotometer on length 420-600 nm. Sealer based on calcium hydroxide Apexit Plus, GuttaFlow silicone based sealer and AH plus epoxy resin based sealer, have shown a low cytotoxicity through the all periods of time on culture of L292 mouse fibroblasts. Methacrylate based sealer, Endorez showed moderate cytotoxicity when freshly mixed and after 7 days. After 24 hours the visibility of the cells was 74,0% and after 48 hours 65,1%. which is slightly cytotoxic. According to results of this study there is a statistically significant difference among the groups p<0,05 for all the tested sealers. Apexit Plus, GuttaFlow and AH plus can be considered as biocompatibile. EndoREZ sealer which is based on methacrylate, after 7 days shows 50,1% of visible live cells which is considered as moderate cytotoxicity.

Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

International Nuclear Information System (INIS)

Pardo, P.J.; Perez, A.L.; Suero, M.I.

2004-01-01

An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision

Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

Science.gov (United States)

Pardo, P. J.; Pérez, A. L.; Suero, M. I.

2004-01-01

An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision.

Visible light nitrogen dioxide spectrophotometer intercomparison: Mount Kobau, British Columbia, July 28 to August 10, 1991

Science.gov (United States)

Mcelroy, C. T.; Elokhov, A. S.; Elansky, N.; Frank, H.; Johnston, P.; Kerr, J. B.

1994-01-01

Under the auspices of the World Meteorological Organization, Environment Canada hosted an international comparison of visible light spectrophotometers at Mt. Kobau, British Columbia in August of 1991. Instruments from four countries were involved. The intercomparison results have indicated that some significant differences exist in the responses of the various instruments, and have provided a basis for the comparison of the historical data sets which currently exist as a result of the independent researches carried out in the past in the former Soviet Union, New Zealand, and Canada.

Calibration Transfer Between a Bench Scanning and a Submersible Diode Array Spectrophotometer for In Situ Wastewater Quality Monitoring in Sewer Systems.

Science.gov (United States)

Brito, Rita S; Pinheiro, Helena M; Ferreira, Filipa; Matos, José S; Pinheiro, Alexandre; Lourenço, Nídia D

2016-03-01

Online monitoring programs based on spectroscopy have a high application potential for the detection of hazardous wastewater discharges in sewer systems. Wastewater hydraulics poses a challenge for in situ spectroscopy, especially when the system includes storm water connections leading to rapid changes in water depth, velocity, and in the water quality matrix. Thus, there is a need to optimize and fix the location of in situ instruments, limiting their availability for calibration. In this context, the development of calibration models on bench spectrophotometers to estimate wastewater quality parameters from spectra acquired with in situ instruments could be very useful. However, spectra contain information not only from the samples, but also from the spectrophotometer generally invalidating this approach. The use of calibration transfer methods is a promising solution to this problem. In this study, calibration models were developed using interval partial least squares (iPLS), for the estimation of total suspended solids (TSS) and chemical oxygen demand (COD) in sewage from Ultraviolet-visible spectra acquired in a bench scanning spectrophotometer. The feasibility of calibration transfer to a submersible, diode array equipment, to be subsequently operated in situ, was assessed using three procedures: slope and bias correction (SBC); single wavelength standardization (SWS) on mean spectra; and local centering (LC). The results showed that SBC was the most adequate for the available data, adding insignificant error to the base model estimates. Single wavelength standardization was a close second best, potentially more robust, and independent of the base iPLS model. Local centering was shown to be inadequate for the samples and instruments used. © The Author(s) 2016.

Comparation studies of uranium analysis method using spectrophotometer and voltammeter

International Nuclear Information System (INIS)

Sugeng Pomomo

2013-01-01

Comparation studies of uranium analysis method by spectrophotometer and voltammeter had been done. The objective of experiment is to examine the reliability of analysis method and instrument performance by evaluate parameters; linearity, accuracy, precision and detection limit. Uranyl nitrate hexahydrate is used as standard, and the sample is solvent mixture of tributyl phosphate and kerosene containing uranium (from phosphoric acid purification unit Petrokimia Gresik). Uranium (U) stripping in the sample use HN0 3 0,5 N and then was analyzed by using of both instrument. Analysis of standard show that both methods give a good linearity by correlation coefficient > 0,999. Spectrophotometry give accuration 99,34 - 101,05 % with ratio standard deviation (RSD) 1,03 %; detection limit (DL) 0,05 ppm. Voltammetry give accuration 95,63 -101,49 % with RSD 3,91 %; detection limit (DL) 0,509 ppm. On the analysis of sludge samples were given the significantly different in result; spectrophotometry give U concentration 4,445 ppm by RSD 6,74 % and voltammetry give U concentration 7,693 by RSD 19,53%. (author)

Microvolume protein concentration determination using the NanoDrop 2000c spectrophotometer.

Science.gov (United States)

Desjardins, Philippe; Hansen, Joel B; Allen, Michael

2009-11-04

Traditional spectrophotometry requires placing samples into cuvettes or capillaries. This is often impractical due to the limited sample volumes often used for protein analysis. The Thermo Scientific NanoDrop 2000c Spectrophotometer solves this issue with an innovative sample retention system that holds microvolume samples between two measurement surfaces using the surface tension properties of liquids, enabling the quantification of samples in volumes as low as 0.5-2 microL. The elimination of cuvettes or capillaries allows real time changes in path length, which reduces the measurement time while greatly increasing the dynamic range of protein concentrations that can be measured. The need for dilutions is also eliminated, and preparations for sample quantification are relatively easy as the measurement surfaces can be simply wiped with laboratory wipe. This video article presents modifications to traditional protein concentration determination methods for quantification of microvolume amounts of protein using A280 absorbance readings or the BCA colorimetric assay.

An in vitro comparison of quantitative light-induced fluorescence-digital and spectrophotometer on monitoring artificial white spot lesions.

Science.gov (United States)

Kim, Hee Eun; Kim, Baek-Il

2015-09-01

The aim of this study was to evaluate the efficacy of quantitative light-induced fluorescence-digital (QLF-D) compared to a spectrophotometer in monitoring progression of enamel lesions. To generate artificial caries with various severities of lesion depths, twenty bovine specimens were immersed in demineralizing solution for 40 days. During the production of the lesions, repeat measurements of fluorescence loss (ΔF) and color change (ΔE) were performed in six distinct stages after the demineralization of the specimens: after 3, 5, 10, 20, 30, and 40 days of exposure to the demineralizing solution. Changes in the ΔF values in the lesions were analyzed using the QLF-D, and changes in the ΔE values in lesions were analyzed using a spectrophotometer. The repeated measures ANOVA of ΔF and ΔE values were used to determine whether there are significant differences at different exposure times in the demineralizing solution. Spearman's rank correlation coefficient was analyzed between ΔF and ΔE. The ΔF values significantly decreased based on the demineralizing period (pmonitoring color changes. Our findings demonstrate that QLF-D are a more efficient and stable tool for early caries detection. Copyright © 2015 Elsevier B.V. All rights reserved.

Design and evaluation of an imaging spectrophotometer incorporating a uniform light source.

Science.gov (United States)

Noble, S D; Brown, R B; Crowe, T G

2012-03-01

Accounting for light that is diffusely scattered from a surface is one of the practical challenges in reflectance measurement. Integrating spheres are commonly used for this purpose in point measurements of reflectance and transmittance. This solution is not directly applicable to a spectral imaging application for which diffuse reflectance measurements are desired. In this paper, an imaging spectrophotometer design is presented that employs a uniform light source to provide diffuse illumination. This creates the inverse measurement geometry to the directional illumination/diffuse reflectance mode typically used for point measurements. The final system had a spectral range between 400 and 1000 nm with a 5.2 nm resolution, a field of view of approximately 0.5 m by 0.5 m, and millimeter spatial resolution. Testing results indicate illumination uniformity typically exceeding 95% and reflectance precision better than 1.7%.

A new colorimetric DPPH• scavenging activity method with no need for a spectrophotometer applied on synthetic and natural antioxidants and medicinal herbs.

Science.gov (United States)

Akar, Zeynep; Küçük, Murat; Doğan, Hacer

2017-12-01

2,2-Diphenyl-1-picrylhydrazyl (DPPH • ) radical scavenging, the most commonly used antioxidant method with more than seventeen thousand articles cited, is very practical; however, as with most assays, it has the major disadvantage of dependence on a spectrophotometer. To overcome this drawback, the colorimetric determination of the antioxidant activity using a scanner and freely available Image J software was developed. In this new method, the mixtures of solutions of DPPH • and standard antioxidants or extracts of common medicinal herbs were dropped onto TLC plates, after an incubation period. The spot images were evaluated with Image J software to determine CSC 50 values, the sample concentrations providing 50% colour reduction, which were very similar with the SC 50 values obtained with spectrophotometric method. The advantages of the new method are the use of lower amounts of reagents and solvents, no need for costly spectrophotometers, and thus significantly lowered costs, and convenient implementation in any environment and situation.

Calibration of a laboratory spectrophotometer for specular light by means of stacked glass plates.

Science.gov (United States)

Allen, W. A.; Richardson, A. J.

1971-01-01

Stacked glass plates have been used to calibrate a laboratory spectrophotometer, over the spectral range 0.5-2.5 microns, for specular light. The uncalibrated instrument was characterized by systematic errors when used to measure the reflectance and transmittance of stacked glass plates. Calibration included first, a determination of the reflectance of a standard composed of barium sulfate paint deposited on an aluminum plate; second, the approximation of the reflectance and transmittance residuals between observed and computed values by means of cubic equations; and, finally, the removal of the systematic errors by a computer. The instrument, after calibration, was accurate to 1% when used to measure the reflectance and transmittance of stacked glass plates.

Protoporphyrin IX induced by 5-aminolevulinic acid in bladder cancer cells in voided urine can be extracorporeally quantified using a spectrophotometer.

Science.gov (United States)

Nakai, Yasushi; Anai, Satoshi; Onishi, Sayuri; Masaomi, Kuwada; Tatsumi, Yoshihiro; Miyake, Makito; Chihara, Yoshitomo; Tanaka, Nobumichi; Hirao, Yoshihiko; Fujimoto, Kiyohide

2015-06-01

We evaluated the feasibility of photodynamic diagnosis of bladder cancer by spectrophotometric analysis of voided urine samples after extracorporeal treatment with 5-aminolevulinic acid (ALA). Sixty-one patients with bladder cancer, confirmed histologically after the transurethral resection of a bladder tumor, were recruited as the bladder cancer group, and 50 outpatients without history of urothelial carcinoma or cancer-related findings were recruited as the control group. Half of the voided urine sample was incubated with ALA (ALA-treated sample), and the rest was incubated without treatment (ALA-untreated sample). For detecting cellular protoporphyrin IX levels, intensity of the samples at the excitation wavelength of 405 nm was measured using a spectrophotometer. The difference between the intensity of the ALA-treated and ALA-untreated samples at 635 nm was calculated. The differences in the bladder cancer group were significantly greater than those in the control group (p spectrophotometer in patients with bladder cancer. Therefore, this cancer detection system has a potential for clinical use. Copyright © 2015 Elsevier B.V. All rights reserved.

Lightness, chroma, and hue distributions in natural teeth measured by a spectrophotometer.

Science.gov (United States)

Pustina-Krasniqi, Teuta; Shala, Kujtim; Staka, Gloria; Bicaj, Teuta; Ahmedi, Enis; Dula, Linda

2017-01-01

The aim of the study was to analyze the distribution of color parameters, lightness (L*), chroma (C), hue (H), a* and b*, in the intercanine sector in maxilla. Patients' tooth color measurements were performed using an intraoral spectrophotometer VITA Easyshade ® (VITA Zahnfabrik H. Rauter GmbH and Co. KG, Bad Sackingen, Germany). The measurements were made in 255 subjects in the intercanine sector in maxilla. The mean values for the group of 255 subjects were as follows: L*, a*, b*, C, and H as 81.6, 0.67, 21.6, 21.7, and 92.7, respectively. For F=206.27 and P < 0.001 between L*, a*, b*, C, H, and central incisor/lateral incisor/canines, there were statistically significant differences. With the statistical analysis, it was determined that there are significant color differences between the teeth of the intercanine sector, which differences are clinically significant also.

Optofluidic UV-Vis spectrophotometer for online monitoring of photocatalytic reactions.

Science.gov (United States)

Wang, Ning; Tan, Furui; Zhao, Yu; Tsoi, Chi Chung; Fan, Xudong; Yu, Weixing; Zhang, Xuming

2016-06-29

On-chip integration of optical detection units into the microfluidic systems for online monitoring is highly desirable for many applications and is also well in line with the spirit of optofluidics technology-fusion of optics and microfluidics for advanced functionalities. This paper reports the construction of a UV-Vis spectrophotometer on a microreactor, and demonstrates the online monitoring of the photocatalytic degradations of methylene blue and methyl orange under different flow rates and different pH values by detecting the intensity change and/or the peak shift. The integrated device consists of a TiO2-coated glass substrate, a PDMS micro-sized reaction chamber and two flow cells. By comparing with the results of commercial equipment, we have found that the measuring range and the sensitivity are acceptable, especially when the transmittance is in the range of 0.01-0.9. This integrated optofluidic device can significantly cut down the test time and the sample volume, and would provide a versatile platform for real-time characterization of photochemical performance. Moreover, its online monitoring capability may enable to access the usually hidden information in biochemical reactions like intermediate products, time-dependent processes and reaction kinetics.

Optofluidic UV-Vis spectrophotometer for online monitoring of photocatalytic reactions

Science.gov (United States)

Wang, Ning; Tan, Furui; Zhao, Yu; Tsoi, Chi Chung; Fan, Xudong; Yu, Weixing; Zhang, Xuming

2016-06-01

On-chip integration of optical detection units into the microfluidic systems for online monitoring is highly desirable for many applications and is also well in line with the spirit of optofluidics technology-fusion of optics and microfluidics for advanced functionalities. This paper reports the construction of a UV-Vis spectrophotometer on a microreactor, and demonstrates the online monitoring of the photocatalytic degradations of methylene blue and methyl orange under different flow rates and different pH values by detecting the intensity change and/or the peak shift. The integrated device consists of a TiO2-coated glass substrate, a PDMS micro-sized reaction chamber and two flow cells. By comparing with the results of commercial equipment, we have found that the measuring range and the sensitivity are acceptable, especially when the transmittance is in the range of 0.01-0.9. This integrated optofluidic device can significantly cut down the test time and the sample volume, and would provide a versatile platform for real-time characterization of photochemical performance. Moreover, its online monitoring capability may enable to access the usually hidden information in biochemical reactions like intermediate products, time-dependent processes and reaction kinetics.

Results of laboratory tests of the information-measurement system of the five-channel spectrophotometer

International Nuclear Information System (INIS)

Bukach, A.B.

1979-01-01

The study of technical characteristics of the five-channel spectrophotometer detecting star spectra in the 3125-8570 A range was carried out. The optimal conditions of photomultipliers and amplifiers allow to count statistically distributed pulses with the time resolution up to 50 ns. Detection, with printing and perforation, of the pulses rate has the absolute error of about +- 1 pulse, when the counting rate changes from 100 to 10 4 s -1 . The step-motor system and the scanning mechanism give the spectral line position with an accuracy of +- 0.2 step (+- 2 Mcm, i.e. 0.03 A for the first order of grating). Instrumental profile effect on the line position is investigated and the dispersion curves are obtained

Elemental investigation of momordica charantia linn. and syzigium jambolana linn. using atomic absorption spectrophotometer

International Nuclear Information System (INIS)

Kazi, T.G.

2002-01-01

Elemental investigation of very important medicinal plant i.e. momordica charantia linn and syzigium jambolana linn, and its decoction has been carried out using flame atomic absorption spectrophotometer. In present study fifteen essential, trace and toxic elements such as Zn, Cr, K, Mg, Ca, Na, Cu, Fe, Pb, Al, Ba, Mn, Co, Ni and Cd were determined in different parts of both plants and in its decoction. The level of essential elements was found high as compared to the level of toxic elements. Both plants are useful in the treatment of diabetes. The validation of the method was checked by employing NBS- 1570 (Spanish) as a standard reference material . The measured values of elements are in close agreement with certified values. (author)

Roughened glass slides and a spectrophotometer for the detection of the wavelength-dependent refractive index of transparent liquids.

Science.gov (United States)

Niskanen, Ilpo; Räty, Jukka; Myllylä, Risto; Sutinen, Veijo; Matsuda, Kiyofumi; Homma, Kazuhiro; Silfsten, Pertti; Peiponen, Kai-Erik

2012-07-01

We describe a method to determine the wavelength-dependent refractive index of liquids by measurement of light transmittance with a spectrophotometer. The method is based on using roughened glass slides with different a priori known refractive indices and immersing the slides into the transparent liquid with unknown refractive index. Using the dispersion data on the glass material it is possible to find the index match between the liquid and the glass slide, and hence the refractive index of the liquid.

Concentration determination of nucleic acids and proteins using the micro-volume BioSpec-nano-spectrophotometer.

Science.gov (United States)

Sukumaran, Suja

2011-02-17

Nucleic acid quantitation procedures have advanced significantly in the last three decades. More and more, molecular biologists require consistent small-volume analysis of nucleic acid samples for their experiments. The BioSpec-nano provides a potential solution to the problems of inaccurate, non-reproducible results, inherent in current DNA quantitation methods, via specialized optics and a sensitive PDA detector. The BioSpec-nano also has automated functionality such that mounting, measurement, and cleaning are done by the instrument, thereby eliminating tedious, repetitive, and inconsistent placement of the fiber optic element and manual cleaning. In this study, data is presented on the quantification of DNA and protein, as well as on measurement reproducibility and accuracy. Automated sample contact and rapid scanning allows measurement in three seconds, resulting in excellent throughput. Data analysis is carried out using the built-in features of the software. The formula used for calculating DNA concentration is: Sample Concentration = DF · (OD260-OD320)· NACF (1) Where DF = sample dilution factor and NACF = nucleic acid concentration factor. The Nucleic Acid concentration factor is set in accordance with the analyte selected. Protein concentration results can be expressed as μg/mL or as moles/L by entering e280 and molecular weight values respectively. When residue values for Tyr, Trp and Cysteine (S-S bond) are entered in the e280Calc tab, the extinction coefficient values are calculated as e280 = 5500 x (Trp residues) + 1490 x (Tyr residues) + 125 x (cysteine S-S bond). The e280 value is used by the software for concentration calculation. In addition to concentration determination of nucleic acids and protein, the BioSpec-nano can be used as an ultra micro-volume spectrophotometer for many other analytes or as a standard spectrophotometer using 5 mm pathlength cells.

Concentration Determination of Nucleic Acids and Proteins Using the Micro-volume Bio-spec Nano Spectrophotometer

Science.gov (United States)

Sukumaran, Suja

2011-01-01

Nucleic Acid quantitation procedures have advanced significantly in the last three decades. More and more, molecular biologists require consistent small-volume analysis of nucleic acid samples for their experiments. The BioSpec-nano provides a potential solution to the problems of inaccurate, non-reproducible results, inherent in current DNA quantitation methods, via specialized optics and a sensitive PDA detector. The BioSpec-nano also has automated functionality such that mounting, measurement, and cleaning are done by the instrument, thereby eliminating tedious, repetitive, and inconsistent placement of the fiber optic element and manual cleaning. In this study, data is presented on the quantification of DNA and protein, as well as on measurement reproducibility and accuracy. Automated sample contact and rapid scanning allows measurement in three seconds, resulting in excellent throughput. Data analysis is carried out using the built-in features of the software. The formula used for calculating DNA concentration is: Sample Concentration = DF · (OD260-OD320)· NACF (1) Where DF = sample dilution factor and NACF = nucleic acid concentration factor. The Nucleic Acid concentration factor is set in accordance with the analyte selected1. Protein concentration results can be expressed as μg/ mL or as moles/L by entering e280 and molecular weight values respectively. When residue values for Tyr, Trp and Cysteine (S-S bond) are entered in the e280Calc tab, the extinction coefficient values are calculated as e280 = 5500 x (Trp residues) + 1490 x (Tyr residues) + 125 x (cysteine S-S bond). The e280 value is used by the software for concentration calculation. In addition to concentration determination of nucleic acids and protein, the BioSpec-nano can be used as an ultra micro-volume spectrophotometer for many other analytes or as a standard spectrophotometer using 5 mm pathlength cells. PMID:21372788

Vulcan - A low-resolution spectrophotometer for measuring the integrated colors of galaxies

International Nuclear Information System (INIS)

Rakos, K.D.; Weiss, W.W.; Mueller, S.; Pressberger, R.; Wachtler, P.

1990-01-01

Recent advances in fiber optics, holographic gratings, and blue CCD sensitivity have been combined to develop a low-resolution spectrophotometer. Combining the principles of aperture photometry and spectroscopy, this device is designed specifically to measure the light from galaxies with low contrast to the sky brightness (i.e., low surface brightness galaxies). The instrument consists of two large apertures (up to several arcmin) with fast-field lens for imaging the entrance pupil onto a fiber-optics cable. The circular configuration for the input end of the fiber cable is modified to a rectangular slit at the output end. The output is then imaged onto a concave holographic grating producing a spectrum from 3200 A to 7600 A with a resolution of 140 A. The main purpose of this instrument is to obtain narrow-band optical colors for low surface brightness galaxies, which can then be applied to the study of stellar populations in these galaxies. 11 refs

Bulk and track etching of PET studied by spectrophotometer

International Nuclear Information System (INIS)

Zhu, Z.Y.; Duan, J.L.; Maekawa, Y.; Koshikawa, H.; Yoshida, M.

2004-01-01

UV-VIS spectra of poly(ethylene terephthalate) (PET) solutions formed by etching PET in NaOH solution were analyzed with respect to the etching time. A linear relationship between absorptions centered at 4.45 and 5.11 eV with weight loss of PET in NaOH solution was established. The relation was applied to study the influence of UV light illumination on bulk etching of PET and to evaluate pore size of etched-through tracks. It is found that bulk etching of PET can be greatly enhanced by UV illumination in air in the wavelength range around 313 nm. A surface area of about 350 nm in thickness shows a 23 times increase in bulk-etching rate after illuminated for 6 h. The phenomenon is attributed to the oxygen-assisted photo-degradation through generating of new photo-unstable species. The enhancement in bulk etching was immediately reduced as the etching proceeds below the surface with an exponential decay constant of about 1.5 μm -1 . Etching of Xe ion irradiated PET films gives extra etching products with similar chemical structure as revealed by spectrophotometer measurements. Quantitative analysis of etching products from latent tracks implies that pores of about 14.6 nm in radius are formed after etching in 0.74 N NaOH at 40 deg. C for 35 min, which is in agreement with the conductometric measurement

Design of a Simple UV Double Beam Spectrophotometer Detector Based on a High Gain Trans Impedance Operational Amplifiers for RNA Measurement

Directory of Open Access Journals (Sweden)

Alakhib Ibrahim Abdelbary

2016-07-01

Full Text Available In this work a simple double beam spectrophotometer detector for the nucleic acid detection has been designed. The developed system contains photodiodes as a sensor, logarithamatic transimpedance amplifier circuit and filter circuit.The developed prototype design accuracy is validated by running a RNA sample and the result shows that our simplified developed setup detects the present of RNA in the sample.

In vitro kinetics of P700+ reduction of Thermosynechococcus elongatus trimeric Photosystem I complexes by recombinant cytochrome c 6 using a Joliot-type LED spectrophotometer.

Science.gov (United States)

Nguyen, Khoa; Vaughn, Michael; Frymier, Paul; Bruce, Barry D

2017-01-01

The reduction rate of photo-oxidized Photosystem I (PSI) with various natural and artificial electron donors have been well studied by transient absorption spectroscopy. The electron transfer rate from various donors to P 700 + has been measured for a wide range of photosynthetic organisms encompassing cyanobacteria, algae, and plants. PSI can be a limiting component due to tedious extraction and purification methods required for this membrane protein. In this report, we have determined the in vivo, intracellular cytochrome c 6 (cyt c 6 )/PSI ratio in Thermosynechococcus elongatus (T.e.) using quantitative Western blot analysis. This information permitted the determination of P 700 + reduction kinetics via recombinant cyt c 6 in a physiologically relevant ratio (cyt c 6 : PSI) with a Joliot-type, LED-driven, pump-probe spectrophotometer. Dilute PSI samples were tested under varying cyt c 6 concentration, temperature, pH, and ionic strength, each of which shows similar trends to the reported literature utilizing much higher PSI concentrations with laser-based spectrophotometer. Our results do however indicate kinetic differences between actinic light sources (laser vs. LED), and we have attempted to resolve these effects by varying our LED light intensity and duration. The standardized configuration of this spectrophotometer will also allow a more uniform kinetic analysis of samples in different laboratories. We can conclude that our findings from the LED-based system display an added total protein concentration effect due to multiple turnover events of P 700 + reduction by cyt c 6 during the longer illumination regime.

Assessing the engagement, learning, and overall experience of students operating an atomic absorption spectrophotometer with remote access technology.

Science.gov (United States)

Erasmus, Daniel J; Brewer, Sharon E; Cinel, Bruno

2015-01-01

The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of engagement, learning, and overall experience. Feedback from students suggests that the use of remote access technology is effective in teaching students the principles of chemical analysis by atomic absorption spectroscopy. © 2014 The International Union of Biochemistry and Molecular Biology.

A New High-sensitivity solar X-ray Spectrophotometer SphinX:early operations and databases

Science.gov (United States)

Gburek, Szymon; Sylwester, Janusz; Kowalinski, Miroslaw; Siarkowski, Marek; Bakala, Jaroslaw; Podgorski, Piotr; Trzebinski, Witold; Plocieniak, Stefan; Kordylewski, Zbigniew; Kuzin, Sergey; Farnik, Frantisek; Reale, Fabio

The Solar Photometer in X-rays (SphinX) is an instrument operating aboard Russian CORONAS-Photon satellite. A short description of this unique instrument will be presented and its unique capabilities discussed. SphinX is presently the most sensitive solar X-ray spectrophotometer measuring solar spectra in the energy range above 1 keV. A large archive of SphinX mea-surements has already been collected. General access to these measurements is possible. The SphinX data repositories contain lightcurves, spectra, and photon arrival time measurements. The SphinX data cover nearly continuously the period since the satellite launch on January 30, 2009 up to the end-of November 2009. Present instrument status, data formats and data access methods will be shown. An overview of possible new science coming from SphinX data analysis will be discussed.

Total ozone trends over the USA during 1979-1991 from Dobson spectrophotometer observations

Science.gov (United States)

Komhyr, Walter D.; Grass, Robert D.; Koenig, Gloria L.; Quincy, Dorothy M.; Evans, Robert D.; Leonard, R. Kent

1994-01-01

Ozone trends for 1979-1991, determined from Dobson spectrophotometer observations made at eight stations in the United States, are augmented with trend data from four foreign cooperative stations operated by NOAA/CMDL. Results are based on provisional data archived routinely throughout the years at the World Ozone Data Center in Toronto, Canada, with calibration corrections applied to some of the data. Trends through 1990 exhibit values of minus 0.3 percent to minus 0.5 percent yr(exp -1) at mid-to-high latitudes in the northern hemisphere. With the addition of 1991 data, however, the trends become less negative, indicating that ozone increased in many parts of the world during 1991. Stations located within the plus or minus 20 deg N-S latitude band exhibit no ozone trends. Early 1992 data show decreased ozone values at some of the stations. At South Pole, Antarctica, October ozone values have remained low during the past 3 years.

Analysis of Shade Matching in Natural Dentitions Using Intraoral Digital Spectrophotometer in LED and Filtered LED Light Sources.

Science.gov (United States)

Chitrarsu, Vijai Krishnan; Chidambaranathan, Ahila Singaravel; Balasubramaniam, Muthukumar

2017-10-31

To evaluate the shade matching capabilities in natural dentitions using Vita Toothguide 3D-Master and an intraoral digital spectrophotometer (Vita Easyshade Advance 4.0) in various light sources. Participants between 20 and 40 years old with natural, unrestored right maxillary central incisors, no history of bleaching, orthodontic treatment, or malocclusion and no rotations were included. According to their shades, subjects were randomly selected and grouped into A1, A2, and A3. A total of 100 participants (50 male and 50 female) in each group were chosen for this study. Shade selection was made between 10 am and 2 pm for all light sources. The same examiner selected the shade of natural teeth with Vita Toothguide 3D-Master under natural light within 2 minutes. Once the Vita Toothguide 3D-Masterwas matched with the maxillary right central incisor, the L*, a*, and b* values, chroma, and hue were recorded with Vita Easyshade Advance 4.0 by placing it on the shade tab under the same light source. The values were statistically analyzed using one-way ANOVA and Tukey's HSD post hoc test with SPSS v22.0 software. The mean ∆E* ab values for shades A1, A2, and A3 for groups 1, 2, and 3 were statistically significantly different from each other (p spectrophotometer showed statistically significant differences in shade matching compared to Vita Toothguide 3D-Master. Incandescent light showed more accurate shade matching than the filtered LED, LED, and daylight. © 2017 by the American College of Prosthodontists.

Spectrophotometer is useful for assessing vitiligo and chemical leukoderma severity by quantifying color difference with surrounding normally pigmented skin.

Science.gov (United States)

Hayashi, M; Okamura, K; Araki, Y; Suzuki, M; Tanaka, T; Abe, Y; Nakano, S; Yoshizawa, J; Hozumi, Y; Inoie, M; Suzuki, T

2018-05-01

Acquired skin hypopigmentation has many etiologies, including autoimmune melanocyte destruction, skin aging, inflammation, and chemical exposure. Distinguishing lesions from normally pigmented skin is clinically important to precisely assess disease severity. However, no gold standard assessment method has been reported. We aimed to investigate whether spectrophotometers are useful for assessing vitiligo and rhododendrol (4-(4-hydroxyphenol)-2-butanol) (Rhododenol ® )-induced leukoderma disease severity by quantifying skin color. Mexameter ® MX18 and CM-700d spectrophotometer were used for assessing vitiligo/leukoderma by measuring melanin index, L*a*b* color space, and ΔE*ab value, which represents the color difference between two subjects and is calculated by the values of L*a*b*. MX18 and CM-700d can quantitatively distinguish vitiligo/leukoderma from normally pigmented skin based on melanin index. CM-700d consistently quantified the color of vitiligo/leukoderma lesions and surrounding normally pigmented skin in L*a*b* color spaces and ΔE*ab. ΔE*ab is well correlated with melanin index and clinical appearance. ΔE*ab has been frequently used in aesthetic dentistry; however, current study is the first to use it in the measurement of skin color. ΔE*ab seems to be a useful parameter to evaluate the color contrast between vitiligo/leukoderma and surrounding normally pigmented skin and can be used to evaluate disease severity and patient's quality of life. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Skin color analysis using a spectrophotometer in Asians.

Science.gov (United States)

Yun, In Sik; Lee, Won Jai; Rah, Dong Kyun; Kim, Yong Oock; Park, Be-young Yun

2010-08-01

To objectively describe skin color, the Commission International d'Eclairage (CIE) L*a*b* color coordinates and melanin and erythema indexes are used. However, it was difficult to understand the relationship among these parameters and to convert them into each other. We introduced a new technique to measure L*a*b* color coordinates and the melanin and erythema indexes at the same time. We analyzed the skin color of normal Asians using this method. The skin color of the forehead, cheek, upper inner arm, dorsum of hand, and anterior chest of 148 volunteers was measured using a spectrophotometer. Using a computer analysis program, L*a*b* values and the melanin and erythema indexes were presented at the same time. The averages of these data were shown according to gender, age, body parts, and correlations among the melanin and erythema indexes and L*a*b* color coordinates, and then they were analyzed. The averages of the melanin and erythema indexes of 148 participants were 1.10 +/- 0.29 and 1.29 +/- 0.38, respectively. The averages of the L*, a*, and b* values were 64.15 +/- 4.86, 8.96 +/- 2.65, and 18.34 +/- 2.39, respectively. The melanin and erythema indexes were higher in males than in females. While the correlation of the melanin index with the L* value was negative, it was positively correlated with the a* and b* values. While the erythema index showed a weak correlation with the b* value, its correlation was negative with the L* value and positive with the a* value. Our method of skin color measurement is useful. We consider the data of this study valuable basic data for the evaluation of colors of pigmental skin diseases and scars in the future.

A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

International Nuclear Information System (INIS)

Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

2013-01-01

The new version MS2 of the in situ on-axis micro-spectrophotometer at the macromolecular crystallography beamline X10SA of the Swiss Light Source supports the concurrent acquisition of Raman, resonance Raman, fluorescence and UV/Vis absorption spectra along with diffraction data. The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years

Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer

Science.gov (United States)

Raimundo, Jr., Ivo M.; Pasquini, Celio

1993-01-01

This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques. PMID:18924979

Comparative Study of the Gross Interpretation of Phototesting and Objective Measurement with Using a Spectrophotometer for Patients with Psoriasis and Vitiligo Treated with Narrow-band UVB.

Science.gov (United States)

Choi, Kyu-Won; Kim, Ki-Ho; Kim, Young-Hun

2009-05-01

Determination of the minimal erythema dose (MED) is important for developing a phototherapy protocol and to diagnosis photosensitivity disorders. But obtaining a precise and reproducible MED is quite difficult because a phototest for erythema is based on subjective assessment. The objective of our study was to compare the gross interpretation of a phototest and the objective measurement using a spectrophotometer for determining the parameters of cutaneous narrow-band UVB (NBUVB) therapy. A total of 14 psoriasis and 10 vitiligo patients who receiving NBUVB phototherapy with skin types III and IV were selected for this study. To perform phototesting, ten sites on the skin of the back were vertically exposed to a series of 10 NBUVB doses among 14 doses between 340 and 1,400 mJ/cm(2). We interpreted the gross findings of erythema and measured the L*a*b* values with using a spectrophotometer at each phototest spot and at the control skin. Also, we evaluate the relationship between the gross presentation and the spectrophotometric analysis by delta E for the assessment of the minimal perceptible erythema (MPE) and MED. For all the subjects, the MEDs were measured in the 490~1,000 mJ/cm(2) range. The average of the colorimetric values for the control skin were L*: 64.8, a*: 7.9 and b*: 19.8. Among them, the L* value and MED value were shown to be inversely correlated, and as the L* value was decreased, the MED was increased. For the MPE, the delta E, which was the color difference of the normal skin and the phototest area, was within the range of 1.5~3.0 in 17 of the 21 patients, and 4 patients were within the range of 1.0~1.5. For the MED, among the 21 patients, the delta E of 17 patients was within the range of 3.0~6.0, and 4 patients were within the range of 6.0~12.0. A spectrophotometer enables UV erythema to be assessed objectively and quantitatively, and this can compensate for the disadvantages of subjective gross interpretation when determining the MED. Delta E is

Measurements in interplanetary space and in the Martian upper atmosphere with a hydrogen absorption-cell spectrophotometer for Lα-radiation on-board Mars 4 - 7 spaceprobes

International Nuclear Information System (INIS)

Babichenko, S.I.; Deregusov, E.V.; Kurt, V.G.; Romanova, N.N.; Skljankin, V.A.; Smirnov, A.S.; Bertaux, J.J.; Blamont, J.

1977-01-01

An ultraviolet spectrophotometer UFS-2, designed to measure radiation of atomic hydrogen in the Lα-line, was installed onboard the interplanetary Mars 4 - 7 spaceprobes launched in August 1973. The absorption cell which was used for the first time outside the hydrogen geocorona allowed direct temperature measurements of neutral interstellar hydrogen near the Sun and in the upper Martian atmosphere. (Auth.)

Results from laboratory and field testing of nitrate measuring spectrophotometers

Science.gov (United States)

Snazelle, Teri T.

2015-01-01

Five ultraviolet (UV) spectrophotometer nitrate analyzers were evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) during a two-phase evaluation. In Phase I, the TriOS ProPs (10-millimeter (mm) path length), Hach NITRATAX plus sc (5-mm path length), Satlantic Submersible UV Nitrate Analyzer (SUNA, 10-mm path length), and S::CAN Spectro::lyser (5-mm path length) were evaluated in the HIF Water-Quality Servicing Laboratory to determine the validity of the manufacturer's technical specifications for accuracy, limit of linearity (LOL), drift, and range of operating temperature. Accuracy specifications were met in the TriOS, Hach, and SUNA. The stock calibration of the S::CAN required two offset adjustments before the analyzer met the manufacturer's accuracy specification. Instrument drift was observed only in the S::CAN and was the result of leaching from the optical path insert seals. All tested models, except for the Hach, met their specified LOL in the laboratory testing. The Hach's range was found to be approximately 18 milligrams nitrogen per liter (mg-N/L) and not the manufacturer-specified 25 mg-N/L. Measurements by all of the tested analyzers showed signs of hysteresis in the operating temperature tests. Only the SUNA measurements demonstrated excessive noise and instability in temperatures above 20 degrees Celsius (°C). The SUNA analyzer was returned to the manufacturer at the completion of the Phase II field deployment evaluation for repair and recalibration, and the performance of the sensor improved significantly.

The Soft X-ray Spectrophotometer SphinX for the CORONAS-Photon Mission

Science.gov (United States)

Sylwester, Janusz; Kowalinski, Miroslaw; Szymon, Gburek; Bakala, Jaroslaw; Kuzin, Sergey; Kotov, Yury; Farnik, Frantisek; Reale, Fabio

The purpose, construction details and calibration results of the new design, Polish-led solar X-ray spectrophotometer SphinX will be presented. The instrument constitutes a part of the Russian TESIS X-ray and EUV complex aboard the forthcoming CORONAS-Photon solar mission to be launched later in 2008. SphinX uses Si-PIN detectors for high time resolution (down to 0.01 s) measurements of solar spectra in the energy range between 0.5 keV and 15 keV. The spectral resolution allows separating 256 individual energy channels in this range with particular groups of lines clearly distinguishable. Unprecedented accuracy of the instrument calibration at the XACT (Palermo) and BESSY (Berlin) synchrotron will allow for establishing the solar soft X-ray photometric reference system. The cross-comparison between SphinX and the other instruments presently in orbit like XRT on Hinode, RHESSI and GOES X-ray monitor, will allow for a precise determination of the coronal emission measure and temperature during both very low and very high activity periods. Examples of the detectors' ground calibration results as well as the calculated synthetic spectra will be presented. The operation of the instrument while in orbit will be discussed allowing for suggestions from other groups to be still included in mission planning.

Method for improving the use of PASCO brand spectrophotometer using DataStudio program applied to radiometric surveys for LAFTLA

International Nuclear Information System (INIS)

Bolanos Rodriguez, Gary

2008-01-01

Escuela de Ingenieria Electrica at the Universidad de Costa Rica has developed a procedure for the improved use of a PASCO brand Spectrophotometer of the Laboratorio de Fotonica y Tecnologia Laser Aplicada. The program has used DataStudio for the application in radiometric surveys in LAFTLA. Important conclusions have been obtained by the assembly of optical experiments, software and data collection and analysis, such as the behavior of a emitting source radiation known as black body and its relation to the temperature, wavelength and intensity of light. The user guide has been detailed exposing calibrations of the sensors, the definition of constants needed for obtaining parameters and assembly and commissioning of the equipment. (author) [es

PHASES: a concept for a satellite-borne ultra-precise spectrophotometer

International Nuclear Information System (INIS)

Burgo, C del; Prieto, C Allende; Peacocke, T

2010-01-01

The Planet Hunting and Asteroseismology Explorer Spectrophotometer, PHASES, is a concept for a space-borne instrument to obtain flux calibrated spectra and measure micro-magnitude photometric variations of nearby stars. The science drivers are the determination of the physical properties of stars and the characterisation of planets orbiting them, to very high precision. PHASES, intended to be housed in a micro-satellite, consists of a 20 cm aperture modified Baker telescope feeding two detectors: the tracking detector, with a field of 1 degree square, and the science detector for performing spectrophotometry. The optical design has been developed with the primary goal of avoiding stray light on the science detector, while providing spectra in the wavelength range 370-960 nm with a resolving power that ranges from ∼ 900 at 370 nm to ∼ 200 at 960 nm. The signal to noise per resolution element obtained for a V = 10 magnitude star in a 1 minute integration varies between ∼ 35 and 140. An analysis of the light curve constrains the radii of the planets relative to their parent stars' radii, which are, in turn, tightly constrained by the combination of absolute spectrophotometry and trigonometric parallaxes. The provisional optical design satisfies all the scientific requirements, including a ∼ 1% rms flux calibration strategy based on observations of bright A-type stars and model atmospheres, allowing the determination of stellar angular diameters for nearby solar-like stars to 0.5%. This level of accuracy will be propagated to the stellar radii for the nearest stars, with highly reliable Hipparcos parallaxes, and more significantly, to the planetary radii.

Modified spectrophotometer for multi-dimensional circular dichroism/fluorescence data acquisition in titration experiments: application to the pH and guanidine-HCI induced unfolding of apomyoglobin.

Science.gov (United States)

Ramsay, G; Ionescu, R; Eftink, M R

1995-01-01

In a previous paper (Ramsay and Eftink, Biophys. J. 66:516-523) we reported the development of a modified spectrophotometer that can make nearly simultaneous circular dichroism (CD) and fluorescence measurements. This arrangement allows multiple data sets to be collected during a single experiment, resulting in a saving of time and material, and improved correlation between the different types of measurements. The usefulness of the instrument was shown by thermal melting experiments on several different protein systems. This CD/fluorometer spectrophotometer has been further modified by interfacing with a syringe pump and a pH meter. This arrangement allows ligand, pH, and chemical denaturation titration experiments to be performed while monitoring changes in the sample's CD, absorbance, fluorescence, and light scattering properties. Our data acquisition program also has an ability to check whether the signals have approached equilibrium before the data is recorded. For performing pH titrations we have developed a procedure which uses the signal from a pH meter in a feedback circuit in order to collect data at evenly spaced pH intervals. We demonstrate the use of this instrument with studies of the unfolding of sperm whale apomyoglobin, as induced by acid pH and by the addition of guanidine-HCI. Images FIGURE 2 PMID:8527683

[The study of the colorimetric characteristics of the cobalt-chrome alloys abutments covered by four different all-ceramic crowns by using dental spectrophotometer].

Science.gov (United States)

Chen, Yifan; Liu, Hongchun; Meng, Yukun; Chao, Yonglie; Liu, Changhong

2015-06-01

This study aims to evaluate the optical data of the different sites of the cobalt-chrome (Co-Cr) alloy abutments covered by four different all-ceramic crowns and the color difference between the crowns and target tab using a digital dental spectrophotometer. Ten Co-Cr alloy abutments were made and tried in four different groups of all-ceramic crowns, namely, Procera aluminia, Procera zirconia, Lava zirconia (Lava-Zir), and IPS E.max glass-ceramic lithium disilicate-reinforced monolithic. The color data of the cervical, body, and incisal sites of the samples were recorded and analyzed by dental spectrophotometer. The CIE L*, a*, b* values were again measured after veneering. The color difference between the abutments covered by all-ceramic crowns and A2 dentine shade tab was evaluated. The L* and b* values of the abutments can be increased by all of the four groups of all-ceramic copings, but a* values were decreased in most groups. A statistical difference was observed among four groups. After being veneered, the L* values of all the copings declined slightly, and the values of a*, b* increased significantly. When compared with A2 dentine shade tab, the ΔE of the crowns was below 4. Four ceramic copings were demonstrated to promote the lightness and hue of the alloy abutments effecttively. Though the colorimetric baseline of these copings was uneven, veneer porcelain can efficiently decrease the color difference between the samples and thee target.

Direct measurement of the fluorescence characteristics of aquatic humic substances by a three-dimensional fluorescence spectrophotometer

International Nuclear Information System (INIS)

Nagao, Seiya; Senoo, Muneaki; Suzuki, Yasuhiro; Nakaguchi, Yuzuru; Hiraki, Keizo.

1997-01-01

Humic substances play an important role in the transport of trace metals and insoluble organic materials. They are also considered to be precursors of trihalomethane in aquatic environments. The direct measurement of humic substances was carried out with a three-dimensional fluorescence spectrophotometer after filtering natural-water samples through a GF/F glass fiber filter. Because the influence of the humic concentration, pH and ionic strength on the three-dimensional excitation emission matrix spectra is negligible, the proposed method can be directly applied to the characterization of humic substances in freshwater samples (humic concentration 0.5-10 mg 1 -1 , pH6-9 and ionic strength <0.04 M) and sea-water samples (ionic strength 0.75 M). Humic substances in river, lake and pore water samples exhibit 2-3 peaks at excitation 305-340 nm/emission 415-440 nm and excitation 250-270 nm/emission 440-450 nm. These peak positions correspond to those of fulvic acids isolated from soil. (author)

[Determination of soil exchangeable base cations by using atomic absorption spectrophotometer and extraction with ammonium acetate].

Science.gov (United States)

Zhang, Yu-ge; Xiao, Min; Dong, Yi-hua; Jiang, Yong

2012-08-01

A method to determine soil exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) by using atomic absorption spectrophotometer (AAS) and extraction with ammonium acetate was developed. Results showed that the accuracy of exchangeable base cation data with AAS method fits well with the national standard referential soil data. The relative errors for parallel samples of exchangeable Ca and Mg with 66 pair samples ranged from 0.02%-3.14% and 0.06%-4.06%, and averaged to be 1.22% and 1.25%, respectively. The relative errors for exchangeable K and Na with AAS and flame photometer (FP) ranged from 0.06%-8.39% and 0.06-1.54, and averaged to be 3.72% and 0.56%, respectively. A case study showed that the determination method for exchangeable base cations by using AAS was proven to be reliable and trustable, which could reflect the real situation of soil cation exchange properties in farmlands.

Application of the correction's system of bottom by deuterium's lamp of a spectrophotometer of atomic absorption to the obtaining of ultraviolet spectrums

International Nuclear Information System (INIS)

Villalobos Chaves, Alberto Enrique

2002-01-01

The correction system of bottom by lamp of deuterium's arch of a spectrophotometer of atomic absorption has been utilized with sweep's capacity of wavelength to get spectrums of ultraviolet absorption of samples in gaseous phase, whether in presence as in absence of flame, in the region between 200 nm and 365 nm. The spectral information was obtained after of a process of electronic subtraction of the source's signal, except for the source's signal plus the sample and its subsequent analysis by a programmed data's processor to give a report in terms of wavelength. The spectrums obtained in absence of flame were practiced in samples contained in a gas's sell for infrared spectroscopy with polyethylene's windows, it is located of the burner and directly in front to the radiation's beam, comparable spectrums with the reported in the literature were obtained and with a bigger resolution than the measure with an conventional ultraviolet absorption's spectrophotometer utilized like reference. The spectrums in presence of flame have been of flame have been obtained from dissolved samples and directly suctioned, it achieves to obtain spectral information that is normally not detected conveniently when it performs qualitative analysis by emission of flame in elements such like zinc, lead, cobalt, mercury and nickel among other. The information obtained on this way has been utilized like an alternative method to the elemental analysis by humid way with a view to increase the reliability of the results that have been utilized like basis in the determination of the tariff classification of imported or exported products. (Author) [es

Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements

International Nuclear Information System (INIS)

Abukassem, I.; Bero, M.A.

2015-01-01

Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC R film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A 633 ) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11 % for spectral absorbance measurements and 15 % for OD measurements. (authors)

Characterization of near-infrared nonmetal atomic emission from an atmospheric helium microwave-induced plasma using a Fourier transform spectrophotometer

International Nuclear Information System (INIS)

Hubert, J.; Van Tra, H.; Chi Tran, K.; Baudais, F.L.

1986-01-01

A new approach for using Fourier transform spectroscopy (FTS) for the detection of atomic emission from an atmospheric helium plasma has been developed and the results obtained are described. Among the different types of plasma source available, the atmospheric pressure microwave helium plasma appears to be an efficient excitation source for the determination of nonmetal species. The more complete microwave plasma emission spectra of Cl, Br, I, S, O, P, C, N, and He in the near-infrared region were obtained and their corrected relative emission intensities are reported. This makes qualitative identification simple, and aids in the quantitative analysis of atomic species. The accuracy of the emission wavelengths obtained with the Fourier transform spectrophotometer was excellent and the resolution provided by the FTS allowed certain adjacent emission lines to be adequate for analytical applications

The study of temperature and UV light effect in anthocyanin extract from dragon fruit (Hylocereus costaricensis) rind using UV-Visible spectrophotometer

Science.gov (United States)

Purbaningtias, Tri Esti; Aprilia, Anisa Cahyani; Fauzi'ah, Lina

2017-12-01

This study aimed to determine the total of anthocyanin content in ethanol extract from super red dragon fruit rind. The extraction was affected by temperature and light conditions. The determination of anthocyanin's total content was performed with a variation of pH and analyzed by UV-Visible spectrophotometer. The results showed that the average contained total anthocyanins obtained at room temperature, 40 and 60 °C were 4.6757, 5.6108, 21.9757 mg/L, respectively. In higher temperatures, it was observed the more anthocyanin extracted. The concentration of anthocyanin extract without UV light was 2.5716 mg/L, it was less than UV light assisted extract, i.e. 5.3770 mg / L.

Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction

International Nuclear Information System (INIS)

Yang Fangwen; Liu Rui; Tan Zhiqiang; Wen Xiaodong; Zheng Chengbin; Lv Yi

2010-01-01

An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl 4 (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I 0 and I i ) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L -1 , with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L -1 . The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water).

Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction.

Science.gov (United States)

Yang, Fangwen; Liu, Rui; Tan, Zhiqiang; Wen, Xiaodong; Zheng, Chengbin; Lv, Yi

2010-11-15

An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl(4) (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I(0) and I(i)) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L(-1), with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L(-1). The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water). Copyright © 2010 Elsevier B.V. All rights reserved.

Comparison between Brewer spectrometer, M 124 filter ozonometer and Dobson spectrophotometer

Science.gov (United States)

Feister, U.

1994-01-01

Concurrent measurements were taken using the Brewer spectrometer no. 30, the filter ozonometer M 124 no. 200 and the Dobson spectrophotometer no. 71 from September 1987 to December 1988 at Potsdam. The performance of the instrument types and the compatibility of ozone data was checked under the conditions of a field measuring station. Total ozone values derived from Dobson AD direct sun measurements were considered as standard. The Dobson instrument had been calibrated at intercomparisons with the World Standard Dobson instrument no. 83 (Boulder) and with the Regional Standard instrument no. 64 (Potsdam), while the Brewer instrument was calibrated several times with the Travelling Standard Brewer no. 17 (Canada). The differences between individual Brewer DS (direct sun) ozone data and Dobson ADDS are within plus or minus 3 percent with half of all differences within plus or minus 1 percent. Less than 0.7 percent of the systematic difference can be due to atmospheric SO2. Due to inadequate regression coefficients Brewer ZB (zenith blue) ozone measurements are by (3...4) percent higher than Dobson ADDS ozone values. M124 DS ozone data are systematically by (1...2) percent higher than Dobson ADDS ozone with 50 percent of the differences within plus or minus 4 percent, but with extreme differences up to plus or minus (20...25) percent. M124 ZB ozone values are by (3...5) percent higher than Dobson ADDS with all the differences within plus or minus 10 percent, i.e. the scatter of differences is smaller for ZB than for M 124 DS measurements, Results for differences in the daily mean ozone values are also addressed. The differences include the uncertainties in the ozone values derived from both types of measurements. They provide an indication of the uncertainty in ozone data and the comparability of ozone values derived from different types of instruments.

Simple and versatile turbidimetric monitoring of bacterial growth in liquid cultures using a customized 3D printed culture tube holder and a miniaturized spectrophotometer: application to facultative and strictly anaerobic bacteria

Directory of Open Access Journals (Sweden)

Margarida R. G. Maia

2016-08-01

Full Text Available Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213 and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897 anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256. For the strictly anaerobic species, a high precision (RSD < 3.5% was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

Science.gov (United States)

Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

2016-01-01

Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

Science.gov (United States)

Abukassem, I; Bero, M A

2015-04-01

Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Total ozone derived from UV spectrophotometer measurements on the NASA CV-990 aircraft for the fall 1976 latitude survey flights

Science.gov (United States)

Hanser, F. A.

1977-01-01

An ultraviolet interference filter spectrophotometer was modified to use a photodiode and was flown on latitude survey flights in the fall of 1976. Comparison with Dobson station total ozone values shows agreement between UVS and Dobson total ozone of + or - 2 percent. The procedure used to convert UVS measured ozone above the aircraft altitude to total ozone above ground level introduces an additional 2 percent deviation for very high altitude UVS ozone data. Under stable aircraft operating conditions, the UVS derived ozone values have a variability, or reproducibility, of better than + or -1 percent. The UVS data from the latitude survey flights yield a detailed latitude profile of total ozone over the Pacific Ocean during November 1976. Significant latitudinal structure in total ozone is found at the middle latitudes (30 deg to 40 deg N and S).

infrared spectrophotometer for simultaneous detection of traces of heavy water and indocyanine green in flowing blood. In vivo experimentation

International Nuclear Information System (INIS)

Capitini, R.; Roveyaz, P.

1981-07-01

We have developed an infrared absorption method for the pulmonary extravascular water and cardiac output determination by the multiple indicator technique. This led us to construct an original double differential spectrophotometer (DUPLEX) for simultaneous detection of traces of heavy water (D 2 O) and indocyanine green (ICG) in circulating blood in a single absorption cell. This DUPLEX is connected to a computer and results are treated on line. D 2 O and ICG are used as non toxic diffusible and vascular tracers respectively. Performances of the DUPLEX are given and show a high accuracy with D 2 O (x 10) and ICG (x 2) compared with the commercial optical analysers. We show the validity of the method for determining the cardiac output and the pulmonary extravascular water in the course of numerous experiments on human and rats subjects. Preliminary results concerning the measurement of global water on rats are also given [fr

Field measurements of the global UV-B radiation: a comparison between a broad-band radiometer and a Brewer spectrophotometer

International Nuclear Information System (INIS)

Anav, A.; Moriconi, M.L.; Di Menno, M.; Giannoccolo, S.

1996-01-01

The spectral responsivity shape plays an important role in the prospect of a wide use of broad-band meters in the UV-B monitoring. As most UV-B broad-band meters have a responsivity approximating an erythemal action spectrum, a measurement campaign was planned to verify if such an instrument could be successfully used to measure the unfiltered global irradiance. A Yankee radiometer mod. UV-B 1 and a Brewer spectrophotometer, considered as a reference meter, were compared for this purpose. A short theoretical treatment of the Yankee radiometer response and some results of the comparison are shown. Only clear-sky days data are selected so that the UV-B radiation reaching the ground could be modelled as the sum of the direct and isotropic diffuse components. The comparison results show a good agreement between the two instruments and confirm the capability of a broad-band UV-B radiometer of correctly measuring the global irradiance

Comparison of Shade of Ceramic with Three Different Zirconia Substructures using Spectrophotometer.

Science.gov (United States)

Habib, Syed Rashid; Shiddi, Ibraheem F Al

2015-02-01

This study assessed how changing the Zirconia (Zr) substructure affected the color samples after they have been overlaid by the same shade of veneering ceramic. Three commercial Zr materials were tested in this study: Prettau(®) Zirconia (ZirKonZahn, Italy), Cercon (Dentsply, Germany) and InCoris ZI (Sirona, Germany). For each system, 15 disk-shaped specimens (10 × 1 mm) were fabricated. Three shades of A1, A2 and A3.5 of porcelain (IPS e.MaxCeram, IvoclarVivadent, USA) were used for layering the specimens. Five specimens from each type of Zr were layered with same shade of ceramic. Color measurements were recorderd by a spectrophotometer Color-Eye(®) 7000A (X-Rite, Grand Rapids, MI). Mean values of L, a, b color coordinates and ΔE were recorded and comparisons were made. Differences in the ΔE were recorded for the same porcelain shade with different Zr substructures and affected the color of the specimens (p < 0.01, ANOVA). The maximum difference between the ΔE values for the A1, A2 and A3.5 shades with three types of Zr substructures was found to be 1.59, 1.69 and 1.45 respectively. Multiple comparisons of the ΔE with PostHoc Tukey test revealed a statistically significant difference (p < 0.05) between the three types of Zr, except between Type 2 Zr and Type 3 Zr for the Shade A1. The mean values of L, a, b and ΔE for the Prettau(®) Zirconia substructure were found to be the least among the three types. The brand of Zr used influences the final color of the all ceramic Zr based restorations and this has clinical significance.

A study of a sector spectrophotometer and auroral O+(2P-2D) emissions

Science.gov (United States)

Swenson, G. R.

1976-01-01

The metastable O+(2P-2D) auroral emission was investigated. The neighboring OH contaminants and low intensity levels of the emission itself necessitated the evolution of an instrument capable of separating the emission from the contaminants and having a high sensitivity in the wavelength region of interest. A new type of scanning photometer was developed and its properties are discussed. The theoretical aspects of auroral electron interaction with atomic oxygen and the resultant O+(2P-2D) emissions were examined in conjunction with N2(+)1NEG emissions. Ground based measurements of O+(2P-2D) auroral emission intensities were made using the spatial scanning photometer (sector spectrophotometer). Simultaneous measurements of N2(+)1NEG sub 1,0 emission intensity were made in the same field of view using a tilting photometer. Time histories of the ratio of these two emissions made in the magnetic zenith during auroral breakup periods are given. Theories of I sub 7319/I sub 4278 of previous investigators were presented. A rocket measurement of N2(+)1NEG sub 0,0 and O+(2P-2D) emission in aurora was examined in detail and was found to agree with the ground based measurements. Theoretical examination resulted in the deduction of the electron impact efficiency generating O+(2P) and also suggests a large source of O+(2P) at low altitude. A possible source is charge exchange of N+(1S) with OI(3P).

Validation of the method spectrophotometer in the histamine determination in fresh tuna (Thunnus Tunna)

International Nuclear Information System (INIS)

Chacon Silva, F.

1998-01-01

The objective of this study was to validate the spectrophotometer method described by Bateman et al. (1994) for the histamine determination in fresh tuna (Thunnus Tunna) and to evaluate the histamine concentration in samples of fresh tuna. To fulfill the recently exposed objectives, the figures of merit were determined like they are it: recovery limits of detection, sensibility and repetitive of the method spectrophotometry and applied the analysis at twenty samples of fresh tuna for copy of the Metropolitan area and three sample like reference of fresh tuna stored 4 degree centigrade by 15 days. The histamine recovery you determines enriching seven ours of fresh tuna with histamine to two levels different 0.613 mg/L and 2.21 mg/L. three samples were left without enriching and you subtract the average to the native histamine. You determines the one it limits of detection using the standard deviation to three levels of concentration of histamine 1.37 mg/L, 2.22 mg/L and 3.22 mg/L, the minimum quantity of hi stamina that you can determine for the method spectrophotometry settling down. The repetitive you determines using the standard deviation for 100 among the average of the histamine values, in seven you replies independent of the same sample. You determines the histamine content, in the fresh tuna Thunnus Tunna of the expends of the Metropolitan Area and in samples of reference stored 4 degrees centigrade by 15 days [es

Loop system for creating jet fuel vapor standards used in the calibration of infrared spectrophotometers and gas chromatographs.

Science.gov (United States)

Reboulet, James; Cunningham, Robert; Gunasekar, Palur G; Chapman, Gail D; Stevens, Sean C

2009-02-01

A whole body inhalation study of mixed jet fuel vapor and its aerosol necessitated the development of a method for preparing vapor only standards from the neat fuel. Jet fuel is a complex mixture of components which partitions between aerosol and vapor when aspirated based on relative volatility of the individual compounds. A method was desired which could separate the vapor portion from the aerosol component to prepare standards for the calibration of infrared spectrophotometers and a head space gas chromatography system. A re-circulating loop system was developed which provided vapor only standards whose composition matched those seen in an exposure system. Comparisons of nominal concentrations in the exposure system to those determined by infrared spectrophotometry were in 92-95% agreement. Comparison of jet fuel vapor concentrations determined by infrared spectrophotometry compared to head space gas chromatography yielded a 93% overall agreement in trial runs. These levels of agreement show the loop system to be a viable method for creating jet fuel vapor standards for calibrating instruments.

Determination of nanomolar chromate in drinking water with solid phase extraction and a portable spectrophotometer.

Science.gov (United States)

Ma, Jian; Yang, Bo; Byrne, Robert H

2012-06-15

Determination of chromate at low concentration levels in drinking water is an important analytical objective for both human health and environmental science. Here we report the use of solid phase extraction (SPE) in combination with a custom-made portable light-emitting diode (LED) spectrophotometer to achieve detection of chromate in the field at nanomolar levels. The measurement chemistry is based on a highly selective reaction between 1,5-diphenylcarbazide (DPC) and chromate under acidic conditions. The Cr-DPC complex formed in the reaction can be extracted on a commercial C18 SPE cartridge. Concentrated Cr-DPC is subsequently eluted with methanol and detected by spectrophotometry. Optimization of analytical conditions involved investigation of reagent compositions and concentrations, eluent type, flow rate (sample loading), sample volume, and stability of the SPE cartridge. Under optimized conditions, detection limits are on the order of 3 nM. Only 50 mL of sample is required for an analysis, and total analysis time is around 10 min. The targeted analytical range of 0-500 nM can be easily extended by changing the sample volume. Compared to previous SPE-based spectrophotometric methods, this analytical procedure offers the benefits of improved sensitivity, reduced sample consumption, shorter analysis time, greater operational convenience, and lower cost. Copyright © 2012 Elsevier B.V. All rights reserved.

Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions.

Science.gov (United States)

Kalmár, József; Dóka, Éva; Lente, Gábor; Fábián, István

2014-03-28

The aqueous photoreactions of three halide ions (chloride, bromide and iodide) were studied using a diode array spectrophotometer to drive and detect the process at the same time. The concentration and pH dependences of the halogen formation rates were studied in detail. The experimental data were interpreted by improving earlier models where the cage complex of a halogen atom and an electron has a central role. The triiodide ion was shown to exert a strong inhibiting effect on the reaction sequence leading to its own formation. An assumed chemical reaction between the triiodide ion and the cage complex interpreted the strong autoinhibition effect. It is shown that there is a real danger of unwanted interference from the photoreactions of halide ions when halide salts are used as supporting electrolytes in spectrophotometric experiments using a relatively high intensity UV light source.

A spectrophotometer-based diffusivity assay reveals that diffusion hindrance of small molecules in extracellular matrix gels used in 3D cultures is dominated by viscous effects.

Science.gov (United States)

Galgoczy, Roland; Pastor, Isabel; Colom, Adai; Giménez, Alicia; Mas, Francesc; Alcaraz, Jordi

2014-08-01

The design of 3D culture studies remains challenging due to the limited understanding of extracellular matrix (ECM)-dependent hindered diffusion and the lack of simple diffusivity assays. To address these limitations, we set up a cost-effective diffusivity assay based on a Transwell plate and the spectrophotometer of a Microplate Reader, which are readily accessible to cell biology groups. The spectrophotometer-based assay was used to assess the apparent diffusivity D of FITC-dextrans with molecular weight (4-70kDa) spanning the physiological range of signaling factors in a panel of acellular ECM gels including Matrigel, fibrin and type I collagen. Despite their technical differences, D data exhibited ∼15% relative difference with respect to FRAP measurements. Our results revealed that diffusion hindrance of small particles is controlled by the enhanced viscosity of the ECM gel in conformance with the Stokes-Einstein equation rather than by geometrical factors. Moreover, we provided a strong rationale that the enhanced ECM viscosity is largely contributed to by unassembled ECM macromolecules. We also reported that gels with the lowest D exhibited diffusion hindrance closest to the large physiologic hindrance of brain tissue, which has a typical pore size much smaller than ECM gels. Conversely, sparse gels (≤1mg/ml), which are extensively used in 3D cultures, failed to reproduce the hindered diffusion of tissues, thereby supporting that dense (but not sparse) ECM gels are suitable tissue surrogates in terms of macromolecular transport. Finally, the consequences of reduced diffusivity in terms of optimizing the design of 3D culture experiments were addressed in detail. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of Fourier transformed infrared spectrophotometer (FTIR) for determination of breastmilk output by the deuterium dilution method among Senegalese women

International Nuclear Information System (INIS)

Sarr Cisse, Aita; Diaham, Babou; Dossou, Nicole; Guiro, Amadou Tidiane; Wade, Salimata; Bluck, Leslie

2002-01-01

Breastmilk output can be estimated from the mother's total body water and water turnover rates after oral administration of deuterium oxide. Usually the deuterium enrichments are determined using a isotope ratio mass spectrometer, which is expensive and requires a specialist for operation and maintenance. Such equipment is dfficult to set up in developing countries. A less expensive method was developed which uses a Fourier transform infrared spectrophotometer (FTIR) for deuterium enrichment analysis. This study evaluated the constraints of using FTIR to study lactating women in Senegal. The deuterium isotope method was found to be adequate for free living subjects and presented few constraints except for the duration of the saliva sampling (14 days). The method offers the opportunity to determine simultaneously breastmilk output, mother's body composition, and breastfeeding practices. Deuterium sample enrichments measured with FTIR were fast and easy, but for spectrum quality some environmental control is required to optimize the results. (Authors)

Normal incidence spectrophotometer using high density transmission grating technology and highly efficiency silicon photodiodes for absolute solar EUV irradiance measurements

Science.gov (United States)

Ogawa, H. S.; Mcmullin, D.; Judge, D. L.; Korde, R.

1992-01-01

New developments in transmission grating and photodiode technology now make it possible to realize spectrometers in the extreme ultraviolet (EUV) spectral region (wavelengths less than 1000 A) which are expected to be virtually constant in their diffraction and detector properties. Time dependent effects associated with reflection gratings are eliminated through the use of free standing transmission gratings. These gratings together with recently developed and highly stable EUV photodiodes have been utilized to construct a highly stable normal incidence spectrophotometer to monitor the variability and absolute intensity of the solar 304 A line. Owing to its low weight and compactness, such a spectrometer will be a valuable tool for providing absolute solar irradiance throughout the EUV. This novel instrument will also be useful for cross-calibrating other EUV flight instruments and will be flown on a series of Hitchhiker Shuttle Flights and on SOHO. A preliminary version of this instrument has been fabricated and characterized, and the results are described.

Influence of surface layer removal of shade guide tabs on the measured color by spectrophotometer and spectroradiometer.

Science.gov (United States)

Kim, Jin-Cheol; Yu, Bin; Lee, Yong-Keun

2008-12-01

To determine the changes in color parameters of Vitapan 3D-Master shade guide tabs by a spectrophotometer (SP) or a spectroradiometer (SR), and by the removal of the surface layer of the tabs that was performed to make a flat measuring surface for the SP color measurement. Color of the shade tabs was measured before and after removing the surface layer of the tabs using SP and SR. Correlations between the color parameters between the original (OR) and the surface layer removed (RM) tabs and between the SP and the SR measurements were determined (alpha=0.05). Based on SP, the lightness, chroma, CIE a* and b* values measured after the surface layer removal were higher than those of the original tabs except a few cases. Based on SR, the chroma and CIE a* and b* values measured after surface layer removal were higher than those of the original tabs except a few cases; however, in case of the lightness, the changes varied by the shade designation. Type of instrument influenced the changes in color parameters based on paired t-test (pspectrophotometer or a spectroradiometer, measurement protocols should be specified because color difference by the surface layer removal and the instrument was high.

Determination of arsenic concentration in tiger tooth croaker (Otolithes ruber and indian halibut (Psettodes erumei using hydride generation atomic absorption spectrophotometer

Directory of Open Access Journals (Sweden)

E Rahimi

2011-11-01

Full Text Available Heavy metal contaminants in fish are of particular interest because of their potential risk to human. This study was undertaken to determine the levels of arsenic in two fish type including tiger tooth croaker and Indian halibut  in Esfahan. A total of 42 fish samples including 28 tiger tooth croaker (Otolithes ruber and 14 Indian halibut (Psettodes erumei were collected from retails of Esfahan from May 2010 to January 2011. For detection of arsenic contamination, the edible muscles of  fish samples were analyzed by hydride generation atomic absorption spectrophotometer. The arsenic contamination in fish samples were found to be in the range of 11 to 98 µg/kg. Concentration of arsenic in tiger tooth croaker and Indian halibut was 11-56 and 32-98 µg/kg, respectively. Arsenic concentrations were below the limit was acceptable to the World Health Organization. According to the results, the concentration of arsenic did not exceed the maximum acceptable intake limit.

Comparison of Ozone Retrievals from the Pandora Spectrometer System and Dobson Spectrophotometer in Boulder, Colorado

Science.gov (United States)

Herman, J.; Evans, R.; Cede, A.; Abuhassan, N.; Petropavlovskikh, I.; McConville, G.

2015-01-01

A comparison of retrieved total column ozone (TCO) amounts between the Pandora #34 spectrometer system and the Dobson #061 spectrophotometer from direct-sun observations was performed on the roof of the Boulder, Colorado, NOAA building. This paper, part of an ongoing study, covers a 1-year period starting on 17 December 2013. Both the standard Dobson and Pandora TCO retrievals required a correction, TCO(sub corr) = TCO (1 + C(T)), using a monthly varying effective ozone temperature, T(sub E), derived from a temperature and ozone profile climatology. The correction is used to remove a seasonal difference caused by using a fixed temperature in each retrieval algorithm. The respective corrections C(T(sub E)) are C(sub Pandora) = 0.00333(T(sub E) - 225) and C(sub Dobson) = -0.0013(T(sub E) - 226.7) per degree K. After the applied corrections removed most of the seasonal retrieval dependence on ozone temperature, TCO agreement between the instruments was within 1% for clear-sky conditions. For clear-sky observations, both co-located instruments tracked the day-to-day variation in total column ozone amounts with a correlation of r(exp 2) = 0.97 and an average offset of 1.1 +/- 5.8 DU. In addition, the Pandora TCO data showed 0.3% annual average agreement with satellite overpass data from AURA/OMI (Ozone Monitoring Instrument) and 1% annual average offset with Suomi-NPP/OMPS (Suomi National Polar-orbiting Partnership, the nadir viewing portion of the Ozone Mapper Profiler Suite).

Intersstellar absorption lines between 2000 and 3000 A in nearby stars observed with BUSS. [Balloon Borne Ultraviolet Spectrophotometer

Science.gov (United States)

De Boer, K. S.; Lenhart, H.; Van Der Hucht, K. A.; Kamperman, T. M.; Kondo, Y.

1986-01-01

Spectra obtained between 2000 and 3000 A with the Balloon Borne Ultraviolet Spectrophotometer (BUSS) payload were examined for interstellar absorption lines. In bright stars, with spectral types between O9V and F5V, such lines were measured of Mg I, Mg II, Cr II, Mn II, Fe II and Zn II, with Cr II and Zn II data of especially high quality. Column densities were derived and interstellar abundances were determined for the above species. It was found that metal depletion increases with increasing E(B-V); Fe was most affected and Zn showed a small depletion for E(B-V) greater than 0.3 towards Sco-Oph. The metal column densities, derived for Alpha-And, Kappa-Dra, Alpha-Com, Alpha-Aql, and 29 Cyg were used to infer N(H I). It was shown that the ratio of Mg I to Na I is instrumental in determining the ionization structure along each line of sight. The spectra of Aql stars confirms the presence of large gas densities near Alpha-Oph. Moreover, data indicated that the Rho-Oph N(H I) value needs to be altered to 35 x 10 to the 20th/sq cm, based on observed ion ratios and analysis of the Copernicus L-alpha profile.

Spectroscopic studies of model photo-receptors: validation of a nanosecond time-resolved micro-spectrophotometer design using photoactive yellow protein and α-phycoerythrocyanin.

Science.gov (United States)

Purwar, Namrta; Tenboer, Jason; Tripathi, Shailesh; Schmidt, Marius

2013-09-13

Time-resolved spectroscopic experiments have been performed with protein in solution and in crystalline form using a newly designed microspectrophotometer. The time-resolution of these experiments can be as good as two nanoseconds (ns), which is the minimal response time of the image intensifier used. With the current setup, the effective time-resolution is about seven ns, determined mainly by the pulse duration of the nanosecond laser. The amount of protein required is small, on the order of 100 nanograms. Bleaching, which is an undesirable effect common to photoreceptor proteins, is minimized by using a millisecond shutter to avoid extensive exposure to the probing light. We investigate two model photoreceptors, photoactive yellow protein (PYP), and α-phycoerythrocyanin (α-PEC), on different time scales and at different temperatures. Relaxation times obtained from kinetic time-series of difference absorption spectra collected from PYP are consistent with previous results. The comparison with these results validates the capability of this spectrophotometer to deliver high quality time-resolved absorption spectra.

An in-line spectrophotometer on a centrifugal microfluidic platform for real-time protein determination and calibration.

Science.gov (United States)

Ding, Zhaoxiong; Zhang, Dongying; Wang, Guanghui; Tang, Minghui; Dong, Yumin; Zhang, Yixin; Ho, Ho-Pui; Zhang, Xuping

2016-09-21

In this paper, an in-line, low-cost, miniature and portable spectrophotometric detection system is presented and used for fast protein determination and calibration in centrifugal microfluidics. Our portable detection system is configured with paired emitter and detector diodes (PEDD), where the light beam between both LEDs is collimated with enhanced system tolerance. It is the first time that a physical model of PEDD is clearly presented, which could be modelled as a photosensitive RC oscillator. A portable centrifugal microfluidic system that contains a wireless port in real-time communication with a smartphone has been built to show that PEDD is an effective strategy for conducting rapid protein bioassays with detection performance comparable to that of a UV-vis spectrophotometer. The choice of centrifugal microfluidics offers the unique benefits of highly parallel fluidic actuation at high accuracy while there is no need for a pump, as inertial forces are present within the entire spinning disc and accurately controlled by varying the spinning speed. As a demonstration experiment, we have conducted the Bradford assay for bovine serum albumin (BSA) concentration calibration from 0 to 2 mg mL(-1). Moreover, a novel centrifugal disc with a spiral microchannel is proposed for automatic distribution and metering of the sample to all the parallel reactions at one time. The reported lab-on-a-disc scheme with PEDD detection may offer a solution for high-throughput assays, such as protein density calibration, drug screening and drug solubility measurement that require the handling of a large number of reactions in parallel.

A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

Science.gov (United States)

Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

2013-01-01

The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years. PMID:23955041

A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source.

Science.gov (United States)

Pompidor, Guillaume; Dworkowski, Florian S N; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R

2013-09-01

The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years.

Non-destructive assessment of grapevine water status in the field using a portable NIR spectrophotometer.

Science.gov (United States)

Tardaguila, Javier; Fernández-Novales, Juan; Gutiérrez, Salvador; Diago, Maria Paz

2017-08-01

Until now, the majority of methods employed to assess grapevine water status have been destructive, time-intensive, costly and provide information of a limited number of samples, thus the ability of revealing within-field water status variability is reduced. The goal of this work was to evaluate the capability of non-invasive, portable near infrared (NIR) spectroscopy acquired in the field, to assess the grapevine water status in diverse varieties, grown under different environmental conditions, in a fast and reliable way. The research was conducted 2 weeks before harvest in 2012, in two commercial vineyards, planted with eight different varieties. Spectral measurements were acquired in the field on the adaxial and abaxial sides of 160 individual leaves (20 leaves per variety) using a commercially available handheld spectrophotometer (1600-2400 nm). Principal component analysis (PCA) and modified partial least squares (MPLS) were used to interpret the spectra and to develop reliable prediction models for stem water potential (Ψ s ) (cross-validation correlation coefficient (r cv ) ranged from 0.77 to 0.93, and standard error of cross validation (SECV) ranged from 0.10 to 0.23), and leaf relative water content (RWC) (r cv ranged from 0.66 to 0.81, and SECV between 1.93 and 3.20). The performance differences between models built from abaxial and adaxial-acquired spectra is also discussed. The capability of non-invasive NIR spectroscopy to reliably assess the grapevine water status under field conditions was proved. This technique can be a suitable and promising tool to appraise within-field variability of plant water status, helpful to define optimised irrigation strategies in the wine industry. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Measurement of breast milk intake using deuterium oxide and fourier transformed infrared spectrophotometer - a pilot study

International Nuclear Information System (INIS)

Adom, T.; Bansa, D.; Boatin, R.; Vuore, T.; Datohe, D.; Timpo, S.; Asamoa-Tutu, P.

2011-01-01

The measurement of breast milk intake of infants is essential to the estimation of nutrient requirements during infancy and lactation. The conventional method, test-weighing procedure for measuring breast milk is time consuming, most often inaccurate and may interfere with the mother's normal activities. A more practical and accurate method is isotope dilution using stable isotope-labelled water. The accuracy and ready availability of deuterium oxide (D 2 O) have led to its extensive use in measuring body composition and breast milk intake of infants. The D 2 O turnover method was field-tested in 13 lactating Ghanaian mother-baby pairs. Maternal and baby anthropometric measurements were made. Baby milk intake and maternal body composition were measured with the dose-to-mother method. Pre-dose samples of saliva were taken from each mother-baby pair. A measured D 2 O dose (30g) was administered orally to the mother. Post-dose saliva samples were collected from mother and baby on days 1, 2, 3, 4, 13, and 14. Samples were analysed using Fourier Transformed Infrared Spectrophotometer (FTIR). The mean ± SD maternal age was 24 ± 5 years. Babies were aged 3.5 months on the average and weighed 6.7 ± 0.7 kg. Mean milk intake of babies was 828 ± 132 ml/day with a range of 610 to 1040 ml/day. Maternal fat free mass and % body fat were 44.8 ± 5.3 kg, 23.1 ± 5.1 respectively. This non-invasive and convenient method has been used successfully to measure breast milk intake of Ghanaian infants. (au)

Image-based ELISA on an activated polypropylene microtest plate--a spectrophotometer-free low cost assay technique.

Science.gov (United States)

Parween, Shahila; Nahar, Pradip

2013-10-15

In this communication, we report ELISA technique on an activated polypropylene microtest plate (APPµTP) as an illustrative example of a low cost diagnostic assay. Activated test zone in APPµTP binds a capture biomolecule through covalent linkage thereby, eliminating non-specific binding often prevalent in absorption based techniques. Efficacy of APPµTP is demonstrated by detecting human immunoglobulin G (IgG), human immunoglobulin E (IgE) and Aspergillus fumigatus antibody in patient's sera. Detection is done by taking the image of the assay solution by a desktop scanner and analyzing the color of the image. Human IgE quantification by color saturation in the image-based assay shows excellent correlation with absorbance-based assay (Pearson correlation coefficient, r=0.992). Significance of the relationship is seen from its p value which is 4.087e-11. Performance of APPµTP is also checked with respect to microtiter plate and paper-based ELISA. APPµTP can quantify an analyte as precisely as in microtiter plate with insignificant non-specific binding, a necessary prerequisite for ELISA assay. In contrast, paper-ELISA shows high non-specific binding in control sera (false positive). Finally, we have carried out ELISA steps on APPµTP by ultrasound waves on a sonicator bath and the results show that even in 8 min, it can convincingly differentiate a test sample from a control sample. In short, spectrophotometer-free image-based miniaturized ELISA on APPµTP is precise, reliable, rapid, and sensitive and could be a good substitute for conventional immunoassay procedures widely used in clinical and research laboratories. Copyright © 2013 Elsevier B.V. All rights reserved.

Influence of Iatrogenic Gaps, Cement Type, and Time on Microleakage of Cast Posts Using Spectrophotometer and Glucose Filtration Measurements.

Science.gov (United States)

Al-Madi, Ebtissam M; Al-Saleh, Samar A; Al-Khudairy, Reem I; Aba-Hussein, Taibah W

2018-04-06

To determine the influence of iatrogenic gaps, type of cement, and time on microleakage of cast posts using spectrophotometer and glucose filtration measurements. Forty-eight single-rooted teeth were divided into eight groups of six teeth each. Teeth were instrumented and obturated, and a cast post was fabricated. In addition to two control groups (positive and negative), a total of six groups were prepared: In four groups, an artificial 2- to 3-mm gap was created between post and residual gutta percha (GP), and two groups were prepared with intimate contact between post and residual GP. Posts were cemented with either zinc phosphate cement or resin cement. Leakage through the post after 1, 8, 14, and 20 days was measured using a glucose penetration model with two different reading methods. Mixed analysis of variance tests were performed to analyze the data. The presence of a gap between the apical end of the post and the most coronal portion of the GP remaining in the root canal after post space preparation increased microleakage significantly. However, microleakage was significantly less when the gap was refilled with GP compared to no gap. There was no difference in leakage between luting cements used. It was concluded that none of the cements were able to prevent microleakage. However, the addition of GP to residual GP did increase the sealing ability.

[Variation in soil Mn fractions as affected by long-term manure amendment using atomic absorption spectrophotometer in a typical grassland of inner Mongolia].

Science.gov (United States)

Fu, Ming-ming; Jiang, Yong; Bai, Yong-fei; Zhang, Yu-ge; Xu, Zhu-wen; Li, Bo

2012-08-01

The effect of sheep manure amendment on soil manganese fractions was conducted in a 11 year experiment at inner Mongolia grassland, using sequential extraction procedure in modified Community Bureau of Reference, and determined by atomic absorption spectrophotometer. Five treatments with dry sheep manure addition rate 0, 50, 250, 750, and 1500 g x m(-2) x yr(-1), respectively, were carried out in this experiment. Results showed that the recovery rate for total Mn was 91.4%-105.9%, as the percentage recovered from the summation of the improved BCR results with aqua regia extractable contents, and it was 97.2%-102.9% from certified soil reference materials. Plant available exchangeable Mn could be enhanced by 47.89%, but reducible and total Mn contents decreased significantly under heavy application of manure at depth of 0-5 cm. The effect of manure amendment on Mn fractions was greater in 0-5 cm than in 5-10 cm soil layer. The results are benefit to micronutrient fractions determination and nutrient management in grassland soils.

iHWG-μNIR: a miniaturised near-infrared gas sensor based on substrate-integrated hollow waveguides coupled to a micro-NIR-spectrophotometer.

Science.gov (United States)

Rohwedder, J J R; Pasquini, C; Fortes, P R; Raimundo, I M; Wilk, A; Mizaikoff, B

2014-07-21

A miniaturised gas analyser is described and evaluated based on the use of a substrate-integrated hollow waveguide (iHWG) coupled to a microsized near-infrared spectrophotometer comprising a linear variable filter and an array of InGaAs detectors. This gas sensing system was applied to analyse surrogate samples of natural fuel gas containing methane, ethane, propane and butane, quantified by using multivariate regression models based on partial least square (PLS) algorithms and Savitzky-Golay 1(st) derivative data preprocessing. The external validation of the obtained models reveals root mean square errors of prediction of 0.37, 0.36, 0.67 and 0.37% (v/v), for methane, ethane, propane and butane, respectively. The developed sensing system provides particularly rapid response times upon composition changes of the gaseous sample (approximately 2 s) due the minute volume of the iHWG-based measurement cell. The sensing system developed in this study is fully portable with a hand-held sized analyser footprint, and thus ideally suited for field analysis. Last but not least, the obtained results corroborate the potential of NIR-iHWG analysers for monitoring the quality of natural gas and petrochemical gaseous products.

Fiberoptic spectrophotometer

Science.gov (United States)

Tans, Petrus P.; Lashof, Daniel A.

1986-01-01

A device for determining the relative composition of a sample of a gas by comparison of the Raman-scattered light of the sample with that of a known gas comprising: a means for passing a single light source through the unknown and the known gases, choppers to alternate the Raman-scattered light into a common light detection and measuring system, optical fiber networks for spatially mixing the resulting Raman scattered light from each sample and directing the mixed light to selective detectors, and a compiler to record the light intensity of each wavelength of Raman-scattered light as a function of the sample from which it originated.

Method Performance of Total Mercury (Hg) Testing in the Biological Samples by Using Cold Vapour Atomic Absorption Spectrophotometer (CV-AAS)

International Nuclear Information System (INIS)

Susanna TS; Samin

2007-01-01

Method performance (validation) of total mercury (Hg) testing in the biological samples by using cold vapour atomic absorption spectrophotometer (CV-AAS) has been done. The objective of this research is to know the method performance of CV-AAS as one of points for the accreditation testing of laboratory according IS0/IEC 17025-2005. The method performance covering limit of detection (LOD), accuracy, precision and bias. As a standard material used SRM Oyster Tissue 15660 from Winopal Forshung Germany, whereas the biological samples were human hair. In principle of mercury testing for solid samples using CV-AAS is dissolving this sample and standard with 10 mL HNO 3 supra pure into a closed quartz tube and heating at 150 °C for 4 hours. The concentration of mercury in each samples was determined at the condition of operation were stirring time (T 1 ) 70 seconds, delay time (T 2 ) 15 seconds, heating time (T 3 ) 13 seconds and cooling time (T 4 ) of 25 seconds. Mercury ion in samples are reduced with SnCl 2 10 % in H 2 SO 4 20 %, and then the vapour of mercury from reduction is passed in NaOH 20 % solution and aquatridest. The result of method performance were: limit of detection (LOD) = 0.085 ng, accuracy 99.70 %, precision (RSD) = 1.64 % and bias = 0.30 %. From the validation result showed that the content of mercury total was in the range of certified values. The total mercury content (Hg) in human hair were varied from 406.93 - 699.07 ppb. (author)

Analysis of Photosystem I Donor and Acceptor Sides with a New Type of Online-Deconvoluting Kinetic LED-Array Spectrophotometer.

Science.gov (United States)

Schreiber, Ulrich; Klughammer, Christof

2016-07-01

The newly developed Dual/KLAS-NIR spectrophotometer, technical details of which were reported very recently, is used in measuring redox changes of P700, plastocyanin (PC) and ferredoxin (Fd) in intact leaves of Hedera helix, Taxus baccata and Brassica napus An overview of various light-/dark-induced changes of deconvoluted P700 + , PC + and Fd - signals is presented demonstrating the wealth of novel information and the consistency of the obtained results. Fd - changes are particularly large after dark adaptation. PC oxidation precedes P700 oxidation during dark-light induction and in steady-state light response curves. Fd reoxidation during induction correlates with the secondary decline of simultaneously measured fluorescence yield, both of which are eliminated by removal of O 2 By determination of 100% redox changes, relative contents of PC/P700 and Fd/P700 can be assessed, which show considerable variations between different leaves, with a trend to higher values in sun leaves. Based on deconvoluted P700 + signals, the complementary quantum yields of PSI, Y(I) (photochemical energy use), Y(ND) (non-photochemical loss due to oxidized primary donor) and Y(NA) (non-photochemical loss due to reduced acceptor) are determined as a function of light intensity and compared with the corresponding complementary quantum yields of PSII, Y(II) (photochemical energy use), Y(NPQ) (regulated non-photochemical loss) and Y(NO) (non-regulated non-photochemical loss). The ratio Y(I)/Y(II) increases with increasing intensities. In the low intensity range, a two-step increase of PC + is indicative of heterogeneous PC pools. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

In situ analysis of proteins at high temperatures mediated by capillary-flow hydrothermal UV-vis spectrophotometer with a water-soluble chromogenic reagent.

Science.gov (United States)

Kawamura, Kunio; Nagayoshi, Hiroki; Yao, Toshio

2010-05-14

In situ monitoring of quantities, interactions, and conformations of proteins is essential for the study of biochemistry under hydrothermal environments and the analysis of hyperthermophilic organisms in natural hydrothermal systems on Earth. We have investigated the potential of a capillary-flow hydrothermal UV-vis spectrophotometer (CHUS) for performing in situ measurements of proteins and determining their behavior at extremely high temperatures, in combination with a chromogenic reagents probe, which interacts with the proteins. The spectral shift obtained using a combination of water-soluble porphyrin (TPPS) and bovine serum albumin (BSA) was the best among the spectral shifts obtained using different combinations of chromogenic reagents and proteins. The association behavior of TPPS with BSA was investigated in detail using CHUS at temperatures up to 175 degrees C and the association constant (K(ass)) of TPPS with BSA was successfully determined at temperatures up to 100 degrees C. The lnK(ass) values were inversely proportional to the T(-1) values in the temperature range 50-100 degrees C. These analyses showed for the first time that the decrease of association of TPPS with BSA is due to the conformational change, fragmentation, and/or denaturing of BSA rather than the decrease of the hydrophobic association between TPPS and BSA. This study conclusively demonstrates the usability of the CHUS system with a chromogenic reagent as an in situ detection and measurement system for thermostable proteins at extremely high temperatures. Copyright 2010 Elsevier B.V. All rights reserved.

Improved fiberoptic spectrophotometer

Science.gov (United States)

Tans, P.P.; Lashof, D.A.

1985-04-02

The present invention allows for accurate spectrophotmetric comparison of the Raman scattering from a sample gas with the Raman scattering from a known gas via a novel fiber optic network. The need for complicated electronic of optical circuit balancing, control, or error compensation circuitry is eliminated. The laser cavity is split into two regions, one of which houses the plasma discharge and produces laser power, and the other of which is adapted to house tubes containing the gas samples. Light from the laser source is beamed simultaneously through samples of the reference gas and the unknown gas, and Raman-scattered light is emitted. The Raman-scattered light from the known and unknown mixtures is then alternately passed through a fiber optic network where the various wavelengths are spatially mixed. The mixed light is then passed into a system of light detectors, each of which are adapted to measure one of the wavelengths of light representing a constituent element of the gases. When the test is complete, each gas sample can be assigned a Raman-scattered profile from the data consisting of the ratios each of the constituent elements bear to each other. (LEW)

Influence of Light Conditions and Light Sources on Clinical Measurement of Natural Teeth Color using VITA Easyshade Advance 4,0® Spectrophotometer. Pilot Study.

Science.gov (United States)

Posavec, Ivona; Prpić, Vladimir; Zlatarić, Dubravka Knezović

2016-12-01

The purpose of this study was to evaluate and compare lightness (L), chroma (C) and hue (h), green-red (a) and blue-yellow (b) character of the color of maxillary right central incisors in different light conditions and light sources. Two examiners who were well trained in digital color evaluation participated in the research. Intraclass correlation coefficients (ICCs) were used to analyze intra- and interobserver reliability. The LCh and L*a*b* values were determined at 08.15 and at 10.00 in the morning under three different light conditions. Tooth color was assessed in 10 subjects using intraoral spectrophotometer VITA Easyshade Advance 4.0 ® set at the central region of the vestibular surface of the measured tooth. Intra- and interobserver ICC values were high for both examiners and ranged from 0.57 to 0.99. Statistically significant differences in LCh and L*a*b* values measured in different time of the day and certain light condition were not found (p>0.05). Statistically significant differences in LCh and L*a*b* values measured under three different light conditions were not found, too (p>0.05). VITA Easyshade Advance 4.0 ® is reliable enough for daily clinical work in order to assess tooth color during the fabrication of esthtic appliances because it is not dependent on light conditions and light sources.

An enzymatic method for the rapid measurement of the hemoglobin A1c by a flow-injection system comprised of an electrochemical detector with a specific enzyme-reactor and a spectrophotometer

International Nuclear Information System (INIS)

Nanjo, Yoko; Hayashi, Ryuzo; Yao, Toshio

2007-01-01

A flow-injection analytical (FIA) system, comprised of an electrochemical detector with a fructosyl-peptide oxidase (FPOX-CET) reactor and a flow-type spectrophotometer, was proposed for the simultaneous measurement of glycohemoglobin and total hemoglobin in blood cell. The blood cell samples were hemolyzed with a surfactant and then treated with protease. In the first stage of operation, total hemoglobin in digested sample was determined spectrophotometrically. In the second stage, fructosyl valyl histidine (FVH) released from glycohemoglobin by the selective proteolysis was determined specifically using the electrochemical detector with the FPOX-CET reactor. The FIA system could be automatically processed at an analytical speed of 40 samples per hour. The proposed assay method could determine selectively only the glycated N-terminal residue of β-chain in glycohemoglobin and total hemoglobin in blood cell. The enzymatic hemoglobin A 1c (HbA 1c ) value calculated by the concentration ratio of the FVH to total hemoglobin, was closely correlated with the HbA 1c values certified by the Japan Diabetic Society (JDS) and the International Federation of Clinical Chemistry (IFCC)

Effect of vital bleaching with solutions containing different concentrations of hydrogen peroxide and pineapple extract as an additive on human enamel using reflectance spectrophotometer: An in vitro study.

Science.gov (United States)

Vejai Vekaash, Chitra Janardhanan; Kumar Reddy, Tripuravaram Vinay; Venkatesh, Kondas Vijay

2017-01-01

This study aims to evaluate the color change in human enamel bleached with three different concentrations of hydrogen peroxide, containing pineapple extract as an additive in two different timings, using reflectance spectrophotometer. The study aimed to investigate the bleaching efficacy on natural teeth using natural enzymes. Baseline color values of 10 randomly selected artificially stained incisors were obtained. The specimens were divided into three groups of 20 teeth each: Group 1 - 30% hydrogen peroxide, Group II - 20% hydrogen peroxide, and Group III - 10% hydrogen peroxide. One half of the tooth was bleached with hydrogen peroxide, and other was bleached with hydrogen peroxide and pineapple extract for 20 min (Subgroup A) and 10 min (Subgroup B). The results were statistically analyzed using student's t -test. The mean ΔE values of Group IA (31.62 ± 0.9), Group IIA (29.85 ± 1.2), and Group IIIA (28.65 ± 1.2) showed statistically significant higher values when compared to the mean Δ E values of Group 1A (25.02 ± 1.2), Group IIA (22.86 ± 1.1), and Group IIIA (16.56 ± 1.1). Identical results were obtained in Subgroup B. The addition of pineapple extract to hydrogen peroxide resulted in effective bleaching.

Support Vector Machine and Artificial Neural Network Models for the Classification of Grapevine Varieties Using a Portable NIR Spectrophotometer.

Directory of Open Access Journals (Sweden)

Salvador Gutiérrez

Full Text Available The identification of different grapevine varieties, currently attended using visual ampelometry, DNA analysis and very recently, by hyperspectral analysis under laboratory conditions, is an issue of great importance in the wine industry. This work presents support vector machine and artificial neural network's modelling for grapevine varietal classification from in-field leaf spectroscopy. Modelling was attempted at two scales: site-specific and a global scale. Spectral measurements were obtained on the near-infrared (NIR spectral range between 1600 to 2400 nm under field conditions in a non-destructive way using a portable spectrophotometer. For the site specific approach, spectra were collected from the adaxial side of 400 individual leaves of 20 grapevine (Vitis vinifera L. varieties one week after veraison. For the global model, two additional sets of spectra were collected one week before harvest from two different vineyards in another vintage, each one consisting on 48 measurement from individual leaves of six varieties. Several combinations of spectra scatter correction and smoothing filtering were studied. For the training of the models, support vector machines and artificial neural networks were employed using the pre-processed spectra as input and the varieties as the classes of the models. The results from the pre-processing study showed that there was no influence whether using scatter correction or not. Also, a second-degree derivative with a window size of 5 Savitzky-Golay filtering yielded the highest outcomes. For the site-specific model, with 20 classes, the best results from the classifiers thrown an overall score of 87.25% of correctly classified samples. These results were compared under the same conditions with a model trained using partial least squares discriminant analysis, which showed a worse performance in every case. For the global model, a 6-class dataset involving samples from three different vineyards, two years

Support Vector Machine and Artificial Neural Network Models for the Classification of Grapevine Varieties Using a Portable NIR Spectrophotometer.

Science.gov (United States)

Gutiérrez, Salvador; Tardaguila, Javier; Fernández-Novales, Juan; Diago, María P

2015-01-01

The identification of different grapevine varieties, currently attended using visual ampelometry, DNA analysis and very recently, by hyperspectral analysis under laboratory conditions, is an issue of great importance in the wine industry. This work presents support vector machine and artificial neural network's modelling for grapevine varietal classification from in-field leaf spectroscopy. Modelling was attempted at two scales: site-specific and a global scale. Spectral measurements were obtained on the near-infrared (NIR) spectral range between 1600 to 2400 nm under field conditions in a non-destructive way using a portable spectrophotometer. For the site specific approach, spectra were collected from the adaxial side of 400 individual leaves of 20 grapevine (Vitis vinifera L.) varieties one week after veraison. For the global model, two additional sets of spectra were collected one week before harvest from two different vineyards in another vintage, each one consisting on 48 measurement from individual leaves of six varieties. Several combinations of spectra scatter correction and smoothing filtering were studied. For the training of the models, support vector machines and artificial neural networks were employed using the pre-processed spectra as input and the varieties as the classes of the models. The results from the pre-processing study showed that there was no influence whether using scatter correction or not. Also, a second-degree derivative with a window size of 5 Savitzky-Golay filtering yielded the highest outcomes. For the site-specific model, with 20 classes, the best results from the classifiers thrown an overall score of 87.25% of correctly classified samples. These results were compared under the same conditions with a model trained using partial least squares discriminant analysis, which showed a worse performance in every case. For the global model, a 6-class dataset involving samples from three different vineyards, two years and leaves

Cross-validity of a portable glucose capillary monitors in relation to enzymatic spectrophotometer methods

Directory of Open Access Journals (Sweden)

William Alves Lima

2006-09-01

Full Text Available The glucose is an important substrate utilizaded during exercise. Accurate measurement of glucose is vital to obtain trustworthy results. The enzymatic spectrophotometer methods are generally considered the “goldstandard” laboratory procedure for measuring of glucose (GEnz, is time consuming, costly, and inappropriate for large scale field testing. Compact and portable glucose monitors (GAccu are quick and easy methods to assess glucose on large numbers of subjects. So, this study aimed to test the cross-validity of GAccu. The sample was composed of 107 men (aged= 35.4±10.7 years; stature= 168.4±6.9 cm; body mass= 73.4±11.2 kg; %fat= 20.9±8.3% – by dual energy x-ray absorptiometry. Blood for measuring fasting glucose was taken in basilar vein (Genz, Bioplus: Bio-2000 and in ring finger (GAccu: Accu-Chek© Advantage©, after a 12-hour overnight fast. GEnz was used as the criterion for cross-validity. Paired t-test shown differences (p RESUMO A glicose é um substrato importante utilizado durante o exercício físico. Medidas acuradas da glicose são fundamentais para a obtenção de resultados confiáveis. O método laboratorial de espectrofotometria enzimática geralmente é considerado o procedimento “padrão ouro” para medir a glicose (GEnz, o qual requer tempo, custo e é inapropriado para o uso em larga escala. Monitores portáteis de glicose (GAccu são rápidos e fáceis para medir a glicose em um grande número de sujeitos. Então, este estudo teve por objetivo testar a validade concorrente do GAccu. A amostra foi composta por 107 homens (idade= 35,4±10,7 anos; estatura= 168,4±6,9 cm; massa corporal= 73,4±11,2 kg; %gordura= 20,9±8,3% – por absortometria de raio-x de dupla energia. O sangue para mensurar a glicose em jejum foi tirado na veia basilar (Genz, Bioplus: Bio-2000 e no dedo anular (GAccu - Accu- Chek© Advantage©, depois de 12h de jejum noturno. O GEnz foi usado como critério para testar a validade

Spectrophotometer-Based Color Measurements

Science.gov (United States)

2017-10-24

equipment. There are several American Society for Testing and Materials ( ASTM ) chapters covering the use of spectrometers for color measurements (refs. 3...Perkin Elmer software and procedures described in ASTM chapter E308 (ref. 3). All spectral data was stored on the computer. A summary of the color...similarity, or lack thereof, between two colors (ref. 5). In this report, the Euclidean distance metric, E, is used and recommended in ASTM D2244

Novel absorptivity centering method utilizing normalized and factorized spectra for analysis of mixtures with overlapping spectra in different matrices using built-in spectrophotometer software.

Science.gov (United States)

Lotfy, Hayam Mahmoud; Omran, Yasmin Rostom

2018-07-05

A novel, simple, rapid, accurate, and economical spectrophotometric method, namely absorptivity centering (a-Centering) has been developed and validated for the simultaneous determination of mixtures with partially and completely overlapping spectra in different matrices using either normalized or factorized spectrum using built-in spectrophotometer software without a need of special purchased program. Mixture I (Mix I) composed of Simvastatin (SM) and Ezetimibe (EZ) is the one with partial overlapping spectra formulated as tablets, while mixture II (Mix II) formed by Chloramphenicol (CPL) and Prednisolone acetate (PA) is that with complete overlapping spectra formulated as eye drops. These procedures do not require any separation steps. Resolution of spectrally overlapping binary mixtures has been achieved getting recovered zero-order (D 0 ) spectrum of each drug, then absorbance was recorded at their maxima 238, 233.5, 273 and 242.5 nm for SM, EZ, CPL and PA, respectively. Calibration graphs were established with good correlation coefficients. The method shows significant advantages as simplicity, minimal data manipulation besides maximum reproducibility and robustness. Moreover, it was validated according to ICH guidelines. Selectivity was tested using laboratory-prepared mixtures. Accuracy, precision and repeatability were found to be within the acceptable limits. The proposed method is good enough to be applied to an assay of drugs in their combined formulations without any interference from excipients. The obtained results were statistically compared with those of the reported and official methods by applying t-test and F-test at 95% confidence level concluding that there is no significant difference with regard to accuracy and precision. Generally, this method could be used successfully for the routine quality control testing. Copyright © 2018 Elsevier B.V. All rights reserved.

Online identification of the antioxidant constituents of traditional Chinese medicine formula Chaihu-Shu-Gan-San by LC-LTQ-Orbitrap mass spectrometry and microplate spectrophotometer.

Science.gov (United States)

Su, Zhi-Heng; Zou, Guo-An; Preiss, Alfred; Zhang, Hong-Wu; Zou, Zhong-Mei

2010-11-02

Chaihu-Shu-Gan-San (CSGS), a traditional Chinese medicine (TCM) formula containing seven herbal medicines, has been used in treatment of gastritis, peptic ulcer, irritable bowel syndrome and depression clinically. However, the chemical constituents in CSGS had not been studied so far. To quickly identify the chemical constituents of CSGS and to understand the chemical profiles related to antioxidant activity of CSGS, liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole orbitrap (LC-LTQ-Orbitrap) mass spectrometry has been applied for online identification of chemical constituents in complex system, meanwhile, antioxidant profile of CSGS was investigated by the fraction collecting and microplate reading system. As a result, 33 chemical constituents in CSGS were identified. Among them, 13 components could be detected both in positive and in negative ion modes, 20 constituents were determined only in positive ion mode and 2 components were only detected in negative ion mode. Meanwhile, the potential antioxidant profile of CSGS was also characterized by combination of 96-well plate collection of elutes from HPLC analysis and microplate spectrophotometer, in which the scavenging activities of free radical produced by DPPH of each fraction could be directly investigated by the analysis of microplate reader. This study quickly screened the contribution of CSGS fractions to the antioxidant activity and online identified the corresponding active constituents. The results indicated that the combination of LC-MS(n) and 96-well plate assay system established in this paper would be a useful strategy for correlating the chemical profile of TCMs with their bioactivities without isolation and purification. Crown Copyright (c) 2010. Published by Elsevier B.V. All rights reserved.

Reviews Book: The Babylonian Theorem Video Game: BrainBox360 (Physics Edition) Book: Teaching and Learning Science: Towards a Personalized Approach Book: Good Practice in Science Teaching: What Research Has to Say Equipment: PAPERSHOW Equipment: SEP Steady State Bottle Kit Equipment: Sciencescope Datalogging Balance Equipment: USB Robot Arm Equipment: Sciencescope Spectrophotometer Web Watch

Science.gov (United States)

2010-07-01

WE RECOMMEND Good Practice in Science Teaching: What Research Has to Say Book explores and summarizes the research Steady State Bottle Kit Another gem from SEP Sciencescope Datalogging Balance Balance suits everyday use Sciencescope Spectrophotometer Device displays clear spectrum WORTH A LOOK The Babylonian Theorem Text explains ancient Egyptian mathematics BrainBox360 (Physics Edition) Video game tests your knowledge Teaching and Learning Science: Towards a Personalized Approach Book reveals how useful physics teachers really are PAPERSHOW Gadget kit is useful but has limitations Robotic Arm Kit with USB PC Interface Robot arm teaches programming WEB WATCH Simple applets teach complex topics

Design of the detector to observe the energetic charged particles: a part of the solar X-ray spectrophotometer ChemiX onboard Interhelio-Probe mission

Science.gov (United States)

Dudnik, Oleksiy; Sylwester, Janusz; Kowalinski, Miroslaw; Bakala, Jaroslaw; Siarkowski, Marek; Evgen Kurbatov, mgr..

2016-07-01

-layer detector stack: first two layers consist of silicon detectors; the third one is based on the p-terphenyl scintillation detector coupled with pixelated silicon photomultiplier. Coincidence logic allows collecting systematic data on particle variety and their energy with 1 and/or 10 s time resolutions. Digital processing unit is constructed based on FPGA Actel ProAsic M1A3PE1500, and contains each event processing logic, forms telemetry data and housekeeping frames, communicates with ChemiX digital processing unit and executes received telecommands. In order to increase the reliability and time resource of the BPM its digital processing unit and secondary power supply unit has backup sets. Switching between backup sets is commanded by externally orders. The BPM is capable to sort out in situ abundances of individual particle constituents from electrons up to oxygen nuclei. 1. O.V.Dudnik, E.V.Kurbatov, V.O.Tarasov, L.A.Andryushenko, I.L.Zajtsevsky, J.Sylwester, J.Bąkala, M.Kowaliński. Background particle detector for the solar X-ray photometer ChemiX of space mission "Interhelioprobe": an adjustment of breadboard model modules (in Russian) / ISSN 1561-8889: Kosmichna Nauka I Tekhnologiya, 2015, Vol.21, No.2, P.3-14. 2. O.V.Dudnik, E.V.Kurbatov, J.Sylwester, M.Siarkowski, P.Podgórski, M.Kowaliński. Background Particle Monitor - a part of the solar X-ray spectrophotometer ChemiX: principles of the operation and construction / in: Abstracts of 15th Ukrainian conference on space research, Odesa, Ukraine, August 24-28, 2015, P.80, doi:10.13140/RG.2.1.2284.2649. 3. O.V.Dudnik, E.V.Kurbatov, M.Kowaliński, M.Siarkowski, P.Podgórski, J.Sylwester. Operational features of Background Particle Monitor, a vital part of the solar X-ray spectrophotometer ChemiX / in: Abstract book of the Conference "Progress on EUV&X-ray spectroscopy and imaging II", Wroclaw, Poland, November 17 19, 2015, P.9, doi:10.13140/RG.2.1.1184.3604.

OBSERVATIONS OF FIVE-MINUTE SOLAR OSCILLATIONS IN THE CORONA USING THE EXTREME ULTRAVIOLET SPECTROPHOTOMETER (ESP) ON BOARD THE SOLAR DYNAMICS OBSERVATORY EXTREME ULTRAVIOLET VARIABILITY EXPERIMENT (SDO/EVE)

International Nuclear Information System (INIS)

Didkovsky, L.; Judge, D.; Wieman, S.; Kosovichev, A. G.; Woods, T.

2011-01-01

We report on the detection of oscillations in the corona in the frequency range corresponding to five-minute acoustic modes of the Sun. The oscillations have been observed using soft X-ray measurements from the Extreme Ultraviolet Spectrophotometer (ESP) of the Extreme Ultraviolet Variability Experiment on board the Solar Dynamics Observatory. The ESP zeroth-order channel observes the Sun as a star without spatial resolution in the wavelength range of 0.1-7.0 nm (the energy range is 0.18-12.4 keV). The amplitude spectrum of the oscillations calculated from six-day time series shows a significant increase in the frequency range of 2-4 mHz. We interpret this increase as a response of the corona to solar acoustic (p) modes and attempt to identify p-mode frequencies among the strongest peaks. Due to strong variability of the amplitudes and frequencies of the five-minute oscillations in the corona, we study how the spectrum from two adjacent six-day time series combined together affects the number of peaks associated with the p-mode frequencies and their amplitudes. This study shows that five-minute oscillations of the Sun can be observed in the corona in variations of the soft X-ray emission. Further investigations of these oscillations may improve our understanding of the interaction of the oscillation modes with the solar atmosphere, and the interior-corona coupling, in general.

Espectrofotometria de longo caminho óptico em espectrofotômetro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa Long optical path length spectrophotometry in conventional double-beam spectrophotometers: a simple alternative for investigating samples of very low optical density

Directory of Open Access Journals (Sweden)

André Luiz Galo

2009-01-01

Full Text Available We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW capillary. Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities. The device uses a custom optical concentrator optically coupled to LCW (TEFLON® AF. Optical density measurements, carried out using a LCW of ~ 45 cm, were in accordance with the Beer-Lambert Law. Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in spectrophotometric measurements.

Determination of fat, moisture, and protein in meat and meat products by using the FOSS FoodScan Near-Infrared Spectrophotometer with FOSS Artificial Neural Network Calibration Model and Associated Database: collaborative study.

Science.gov (United States)

Anderson, Shirley

2007-01-01

A collaborative study was conducted to evaluate the repeatability and reproducibility of the FOSS FoodScan near-infrared spectrophotometer with artificial neural network calibration model and database for the determination of fat, moisture, and protein in meat and meat products. Representative samples were homogenized by grinding according to AOAC Official Method 983.18. Approximately 180 g ground sample was placed in a 140 mm round sample dish, and the dish was placed in the FoodScan. The operator ID was entered, the meat product profile within the software was selected, and the scanning process was initiated by pressing the "start" button. Results were displayed for percent (g/100 g) fat, moisture, and protein. Ten blind duplicate samples were sent to 15 collaborators in the United States. The within-laboratory (repeatability) relative standard deviation (RSD(r)) ranged from 0.22 to 2.67% for fat, 0.23 to 0.92% for moisture, and 0.35 to 2.13% for protein. The between-laboratories (reproducibility) relative standard deviation (RSD(R)) ranged from 0.52 to 6.89% for fat, 0.39 to 1.55% for moisture, and 0.54 to 5.23% for protein. The method is recommended for Official First Action.

A Portable Diode Array Spectrophotometer.

Science.gov (United States)

Stephenson, David

2016-05-01

A cheap portable visible light spectrometer is presented. The spectrometer uses readily sourced items and could be constructed by anyone with a knowledge of electronics. The spectrometer covers the wavelength range 450-725 nm with a resolution better than 5 nm. The spectrometer uses a diffraction grating to separate wavelengths, which are detected using a 128-element diode array, the output of which is analyzed using a microprocessor. The spectrum is displayed on a small liquid crystal display screen and can be saved to a micro SD card for later analysis. Battery life (2 × AAA) is estimated to be 200 hours. The overall dimensions of the unit are 120 × 65 × 60 mm, and it weighs about 200 g. © The Author(s) 2016.

asan alternative to conventional spectrophotometers

African Journals Online (AJOL)

signal whi:h can be processd in a multitude of increasingly complex ways in order to cxtraet as much ehemical information as possible. Apart from the fact that the LEDs are cheap. copact and commercially available, equipment constructed from this system have smalt size. fight weight. low power consumption and negligible ...

SphinX x-ray spectrophotometer

Science.gov (United States)

Kowaliński, Mirosław

2012-05-01

This paper presents assumptions to a PhD thesis. The thesis will be based on the construction of Solar Photometer in X-rays (SphinX). SphinX was an instrument developed to detect the soft X-rays from the Sun. It was flown on board the Russian CORONAS-Photon satellite from January 30, 2009 to the end of November, 2009. During 9 months in orbit SphinX provided an excellent and unique set of observations. It revealed about 750 flares and brightenings. The instrument observed in energy range 1.0 - 15.0 keV with resolution below ~0.5 keV. Here, the SphinX instrument objectives, design, performance and operation principle are described. Below results of mechanical and thermal - vacuum tests necessary to qualify the instrument to use in space environment are presented. Also the calibration results of the instrument are discussed. In particular detail it is described the Electrical Ground Support Equipment (EGSE) for SphinX. The EGSE was used for all tests of the instrument. At the end of the paper results obtained from the instrument during operation in orbit are discussed. These results are compared with the other similar measurements performed from the separate spacecraft instruments. It is suggested design changes in future versions of SphinX.

[The content of mineral elements in Camellia olei fera ovary at pollination and fertilization stages determined by auto discrete analyzers and atomic absorption spectrophotometer].

Science.gov (United States)

Zou, Feng; Yuan, De-Yi; Gao, Chao; Liao, Ting; Chen, Wen-Tao; Han, Zhi-Qiang; Zhang, Lin

2014-04-01

In order to elucidate the nutrition of Camellia olei fera at pollination and fertilization stages, the contents of mineral elements were determined by auto discrete analyzers and atomic absorption spectrophotometer, and the change in the contents of mineral elements was studied and analysed under the condition of self- and cross-pollination. The results are showed that nine kinds of mineral elements contents were of "S" or "W" type curve changes at the pollination and fertilization stages of Camellia olei fera. N, K, Zn, Cu, Ca, Mn element content changes showed "S" curve under the self- and out-crossing, the content of N reaching the highest was 3.445 8 mg x g(-1) in self-pollination of 20 d; K content reaching the highest at the cross-pollination 20 d was 6.275 5 mg x g(-1); Zn content in self-pollination of 10 d reaching the highest was 0.070 5 mg x g(-1); Cu content in the cross-pollination of 5 d up to the highest was 0.061 0 mg x g(-1); Ca content in the cross-pollination of 15 d up to the highest was 3.714 5 mg x g(-1); the content of Mn reaching the highest in self-pollination 30 d was 2. 161 5 mg x g(-1). Fe, P, Mg element content changes was of "S" type curve in selfing and was of "W" type curve in outcrossing, Fe content in the self-pollination 10 d up to the highest was 0.453 0 mg x g(-1); P content in self-pollination of 20 d reaching the highest was 6.731 8 mg x g(-1); the content of Mg up to the highest in self-pollination 25 d was 2.724 0 mg x g(-1). The results can be used as a reference for spraying foliar fertilizer, and improving seed setting rate and yield in Camellia olei fera.

Method development for the determination of fluorine in toothpaste via molecular absorption of aluminum mono fluoride using a high-resolution continuum source nitrous oxide/acetylene flame atomic absorption spectrophotometer.

Science.gov (United States)

Ozbek, Nil; Akman, Suleyman

2012-05-30

Fluorine was determined via the rotational molecular absorption line of aluminum mono fluoride (AlF) generated in C(2)H(2)/N(2)O flame at 227.4613 nm using a high-resolution continuum source flame atomic absorption spectrophotometer (HR-CS-FAAS). The effects of AlF wavelength, burner height, fuel rate (C(2)H(2)/N(2)O) and amount of Al on the accuracy, precision and sensitivity were investigated and optimized. The Al-F absorption band at 227.4613 nm was found to be the most suitable analytical line with respect to sensitivity and spectral interferences. Maximum sensitivity and a good linearity were obtained in acetylene-nitrous oxide flame at a flow rate of 210 L h(-1) and a burner height of 8mm using 3000 mg L(-1) of Al for 10-1000 mg L(-1)of F. The accuracy and precision of the method were tested by analyzing spiked samples and waste water certified reference material. The results were in good agreement with the certified and spiked amounts as well as the precision of several days during this study was satisfactory (RSD<10%). The limit of detection and characteristic concentration of the method were 5.5 mg L(-1) and 72.8 mg L(-1), respectively. Finally, the fluorine concentrations in several toothpaste samples were determined. The results found and given by the producers were not significantly different. The method was simple, fast, accurate and sensitive. Copyright © 2012 Elsevier B.V. All rights reserved.

Defense meteorological satellite measurements of total ozone

International Nuclear Information System (INIS)

Lovill, J.E.; Ellis, J.S.; Luther, F.M.; Sullivan, R.J.; Weichel, R.L.

1992-01-01

A multichannel filter radiometer (MFR) on Defense Meteorological Satellites (DMS) that measured total ozone on a global-scale from March 1977 - February 1980 is described. The total ozone data measured by the MFR were compared with total ozone data taken by surfaced-based Dobson spectrophotometers. When comparisons were made for five months, the Dobson spectrophotometer measured 2-5% more total ozone than the MFR. Comparisons between the Dobson spectrophotometer and the MFR showed a reduced RMS difference as the comparisons were made at closer proximity. A Northern Hemisphere total ozone distribution obtained from MFR data is presented

Measurement of opalescence of tooth enamel.

Science.gov (United States)

Lee, Yong-Keun; Yu, Bin

2007-08-01

Opalescent dental esthetic restoratives look natural and esthetic in any light, react to light in the same manner as the natural tooth and show improved masking effect. The objective of this study was to determine the opalescence of tooth enamel with reflection spectrophotometers. Color of intact bovine and human enamel was measured in the reflectance and transmittance modes. Two kinds of spectrophotometers were used for bovine and one kind was used for human enamel. The opalescence parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Deltab(*)) and red-green color coordinate (CIE Deltaa(*)) between the reflected and transmitted colors. Mean OP value of bovine enamel was 10.6 (+/-1.4) to 19.0 (+/-2.1), and varied by the configuration of spectrophotometers. Mean OP value of human enamel was 22.9 (+/-1.9). Opalescence varied by the configuration of measuring spectrophotometer and the species of enamel. These values could be used in the development of esthetic restorative materials.

Instrumentation

Energy Technology Data Exchange (ETDEWEB)

None

1973-07-01

Developments discussed include a transistorized- power supply for the Beckman DU spectrophotometer, a master clock pulse generator, a modular printing unit, a flash photolysis setup, a glove box assembly for a Perkin-Elmer infrared spectrophotometer, and a Faraday balance for measuring the magnetic susceptibilities of actinide compounds. (WHK)

An Effective and Economical Photometer for Classroom Demonstrations and Laboratory Use

Science.gov (United States)

Butterfield, Anthony E.; Young, Colin C.

2012-01-01

We present a simple, effective, and inexpensive spectrophotometer design that may be used in a stand-alone teaching module, and to enhance various unit operations experiments. The spectrophotometers described performed as well as a commercial option at estimating cell concentration in a bioreactor and tracking a first-order reaction. Such devices…

Reviews Equipment: Vibration detector Equipment: SPARK Science Learning System PS-2008 Equipment: Pelton wheel water turbine Book: Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book: Outliers: The Story of Success Book: T-Minus: The Race to the Moon Equipment: Fridge Rover Equipment: Red Tide School Spectrophotometer Web Watch

Science.gov (United States)

2010-03-01

WE RECOMMEND Vibration detector SEP equipment measures minor tremors in the classroom SPARK Science Learning System PS-2008 Datalogger is easy to use and has lots of added possibilities Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book is crammed with the latest on the atom bomb T-Minus: The Race to the Moon Graphic novel depicts the politics as well as the science Fridge Rover Toy car can teach magnetics and energy, and is great fun Red Tide School Spectrophotometer Professional standard equipment for the classroom WORTH A LOOK Pelton wheel water turbine Classroom-sized version of the classic has advantages Outliers: The Story of Success Study of why maths is unpopular is relevant to physics teaching WEB WATCH IOP webcasts are improving but are still not as impressive as Jodrell Bank's Chromoscope website

Untitled

Indian Academy of Sciences (India)

The infra-red spectra were obtained with a Perkin-Elmcr model 221 spectrophotometer in thc region 700-4000 cm.-* and also on a Perkin-Elmer model 331 grating spectrophotometer in the region 400—4000 cm.* The solid samples were in the form of KBr pellets; the mull technique was also employed. The data for urea ...

CIEL*a*b* color space predictive models for colorimetry devices--analysis of perfume quality.

Science.gov (United States)

Korifi, Rabia; Le Dréau, Yveline; Antinelli, Jean-François; Valls, Robert; Dupuy, Nathalie

2013-01-30

Color perception plays a major role in the consumer evaluation of perfume quality. Consumers need first to be entirely satisfied with the sensory properties of products, before other quality dimensions become relevant. The evaluation of complex mixtures color presents a challenge even for modern analytical techniques. A variety of instruments are available for color measurement. They can be classified as tristimulus colorimeters and spectrophotometers. Obsolescence of the electronics of old tristimulus colorimeter arises from the difficulty in finding repair parts and leads to its replacement by more modern instruments. High quality levels in color measurement, i.e., accuracy and reliability in color control are the major advantages of the new generation of color instrumentation, the integrating sphere spectrophotometer. Two models of spectrophotometer were tested in transmittance mode, employing the d/0° geometry. The CIEL(*)a(*)b(*) color space parameters were measured with each instrument for 380 samples of raw materials and bases used in the perfume compositions. The results were graphically compared between the colorimeter device and the spectrophotometer devices. All color space parameters obtained with the colorimeter were used as dependent variables to generate regression equations with values obtained from the spectrophotometers. The data was statistically analyzed to create predictive model between the reference and the target instruments through two methods. The first method uses linear regression analysis and the second method consists of partial least square regression (PLS) on each component. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of instrumental parameters for obtaining acceptable analytical results of the Dosimetry Laboratory of Chemistry of the Regional Center of Nuclear Sciences, CNEN-NE, Recife, Brazil

International Nuclear Information System (INIS)

Souza, V.L.B.; Figueiredo, M.D.C.; Cunha, M.S.

2008-01-01

Instrumental parameters need to be evaluated for obtaining acceptable analytical results for a specific instrument. The performance of the UV-VIS spectrophotometer can be verified for wavelengths and absorbances with appropriate materials (solutions of different concentrations of K 2 CrO 4 , for example). The aim of this work was to demonstrate the results of the procedures to control the quality of the measurements carried out in the laboratory in the last four years. The samples were analyzed in the spectrophotometer and control graphics were obtained for K 2 CrO 4 and Fe 3+ absorbance values. The variation in the results obtained for the stability of the spectrophotometer and for the control of its calibration did not exceed 2%. (author)

Data on fluoride concentration level in villages of Asara (Alborz, Iran) and daily fluoride intake based on drinking water consumption.

Science.gov (United States)

Akhavan, Giti; Dobaradaran, Sina; Borazjani, Jaleh Mohajeri

2016-12-01

In the present data article, fluoride concentration levels of drinking water (with spring or groundwater sources) in 10 villages of Asara area located in Alborz province were determined by the standard SPADNS method using a spectrophotometer (DR/2000 Spectrophotometer, USA). Daily fluoride intakes were also calculated based on daily drinking water consumption. The fluoride content were compared with EPA and WHO guidelines for drinking water.

Spectrophotometers for plutonium monitoring in HB-line

Energy Technology Data Exchange (ETDEWEB)

Lascola, R. J. [Savannah River Site (SRS), Aiken, SC (United States); O' Rourke, P. E. [Savannah River Site (SRS), Aiken, SC (United States); Kyser, E. A. [Savannah River Site (SRS), Aiken, SC (United States); Immel, D. M. [Savannah River Site (SRS), Aiken, SC (United States); Plummer, J. R. [Savannah River Site (SRS), Aiken, SC (United States); Evans, E. V. [Savannah River Site (SRS), Aiken, SC (United States)

2016-02-12

This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

Application of Modern Colour Measurement Dervices in Coloration Industries

Institute of Scientific and Technical Information of China (English)

CHUNG Y.S.; XIN John H.; SIN K.M.

2002-01-01

In colour measurement ralated industry, reflectance spectrophotometer is the one of the popular measuring machine for measutring colour and quality control. Colour communications is frequently confusing. This is because the colour appearance is subject to the influence of at least three different phenomena: the light source, the object and the visual system. The variation in either the radiant quantity or the spectral distribution of the source can alter the observed colour. Because of this reason,the objective quantitative tool, colour measurement equipment and communication method; become more important in evaluating of the colour. In fact, based on the advanced in computer system and electronic device,the colour measurement becomes more and more accuracy, especiany in spectrophotometer measurement.In this paper, we will focus on the review of modern spectrophotometers in coloration industries.

Effect of R.F. Power to the Structural Properties of ZnO Thin Films Deposited by Magnetron Sputtering

International Nuclear Information System (INIS)

Sin, N.D.M.; Rusop, M.

2011-01-01

The effect of RF power variation (100 watt∼400 watt ) on the zinc oxide (ZnO) thin films electrical, optical and structural properties were examined using current voltage (I-V) measurement, UV-Vis-NIR spectrophotometer, x-ray diffraction (XRD) and atomic force microscope (AFM). ZnO thin films were prepared at room temperature in pure argon atmosphere by a RF magnetron sputtering using ZnO target. The resistivity of thin film show the lowest at 300 watt. The absorption coefficient spectra obtained from UV-Vis-NIR spectrophotometer measurement show all films have low absorbance in visible and near infrared (IR) region but have high UV absorption properties using UV-VIS spectrophotometer (JASCO 670) . Highly oriented ZnO thin films [002] direction were obtained by using Rigaku Ultima IV. (author)

Health impacts of mercury cycling in contaminated environments of Central India studied by NAA and ICP-MS

International Nuclear Information System (INIS)

Patel, Khageshwar Singh

2002-01-01

The environmental and atmospheric samples i.e. surface water, ground water, surface soil, sediment, rain and fog from various sites of contaminated environments of central India were collected in year, 2000-2001. The concentration levels of total-Hg in these samples were analyzed by using techniques i.e. cold vapor- atomic absorption spectrophotometer (CV-AAS), X-ray fluorescence spectrophotometer XFS). Further, the data base of total Hg in the environmental samples would be validated in other laboratories i.e. Prof Dr. Klaus Heumann (Johannes Gutenberg-University, Mainz, Germany), David Amouroux (University of Pau, France) and Dr Joerg Feldmann (University of Aberdeen, Scotland, UK) for exploration of the Hg-contaminated environments by using techniques i.e. ICP-MS/GC, gas chromatography-induced couple atomic emission spectrophotometer (GC-ICP-AES), neutron activation analysis (NAA). (author)

Visible light photocatalytic activities of template free porous graphitic carbon nitride-BiOBr composite catalysts towards the mineralization of reactive dyes

Science.gov (United States)

Kanagaraj, Thamaraiselvi; Thiripuranthagan, Sivakumar; Paskalis, Sahaya Murphin Kumar; Abe, Hideki

2017-12-01

Template free porous g-C3N4 (pGCN) and flower like bismuth oxybromide catalysts were synthesized by poly condensation and precipitation methods respectively. Various weight percentages of porous GCN-BiOBr composite catalysts (x% pGCN-BiOBr where x = 5, 10, 30, 50 & 70 wt% of pGCN) were synthesized by impregnation method. All the synthesized catalysts were characterized by X-Ray diffractometer, Fourier transform infrared spectrophotometer, BET surface area analyzer, UV Visible diffuse reflectance spectrophotometer, X-Ray photoelectron spectrophotometer, SEM with Energy dispersive X-ray analyzer (SEM/EDAX) and elemental mapping, Transmission electron microscope, Photoluminescence spectrophotometer and Electrochemical impedance. Photocatalytic degradation of all the synthesized catalysts were tested towards the harmful reactive dyes such as reactive blue 198 (RB 198), reactive black 5 (RB 5) and reactive yellow 145 (RY 145) in presence of visible irradiation. Among the catalysts 30% pGCN-BiOBr resulted in the highest photocatalytic activity towards the degradation of all the three dyes in presence of UV, visible and solar irradiations. Kinetics studies on the photocatalytic mineralization of dyes indicated that it followed pseudo first order. HPLC, TOC and COD studies confirm that the dyes are mineralized into CO2, water and mineral salts.

Assessment of dose measurement uncertainty using RisoScan

International Nuclear Information System (INIS)

Helt-Hansen, Jakob; Miller, Arne

2006-01-01

The dose measurement uncertainty of the dosimeter system RisoScan, office scanner and Riso B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectively, at one standard deviation. The subroutine in RisoScan for electron energy measurement is shown to give results that are equivalent to the measurements with a scanning spectrophotometer

Isolasi Dan Analisis Kimia Minyak Atsiri Dari Bunga Kecombrang (Etlingera Elatior) Dengan Gas Kromatografi-Spektrometer Massa (GC-MS) Dan Uji Aktivitas Anti Bakteri

OpenAIRE

Perangin Angin, Mawar Indah

2016-01-01

In this study has been treated isolation and analyze its chemical component of volatile oil of Etlingera e. obtained from district of Nang Belawan sub district of Simpang Empat in Karo Regency. The isolated volatile oil used Stahl tool. Chemical composition for each outcome of isolation was treated analysis using Gas chromatography Mass Spectrophotometer (GC-MS) device and Infra Red Spectrophotometer. The outcome isolation of Etlingera e.by distillation using Stahl device some 450 gram sa...

Assessment of dose measurement uncertainty using RisøScan

DEFF Research Database (Denmark)

Helt-Hansen, J.; Miller, A.

2006-01-01

The dose measurement uncertainty of the dosimeter system RisoScan, office scanner and Riso B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectiv......%, respectively, at one standard deviation. The subroutine in RisoScan for electron energy measurement is shown to give results that are equivalent to the measurements with a scanning spectrophotometer. (c) 2006 Elsevier Ltd. All rights reserved....

Phosphate solubilizing bacteria around Indian peninsula

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

nitrophenylphosphate by the culture. One mole of nitrophenol is equivalent to 1 atom of phosphorus. The absorbance was read at 418 nm using DU-6 Beckmann spectrophotometer. The activity was expressed as ?mol.Pml-1d-1. The cultures which showed good phosphate... suitable controls. Growth was measured at 600 nm using DU-6 Beckmann spectrophotometer and phosphatase activity was measured as described earlier. For testing the rate of survival of PSB on various carriers 2 g of finely powdered sediment, rice...

Water transparency measurements in the deep Ionian Sea

CERN Document Server

Anassontzis, E G; Belias, A; Fotiou, A; Grammatikakis, G; Kontogiannis, H; Koske, P; Koutsoukos, S; Lykoussis, V; Markopoulos, E; Psallidas, A; Resvanis, L K; Siotis, I; Stavrakakis, S; Stavropoulos, G; Zhukov, V A

2010-01-01

A long optical base line spectrophotometer designed to measure light transmission in deep sea waters is described. The variable optical path length allows measurements without the need for absolute or external calibration. The spectrophotometer uses eight groups of uncollimated light sources emitting in the range 370–530 nm and was deployed at various depths at two locations in the Ionian Sea that are candidate sites for a future underwater neutrino telescope. Light transmission spectra at the two locations are presented and compared.

Comparisons of radiation dosimetry between Louvain (Belgium) and Edinburgh (UK)

International Nuclear Information System (INIS)

Law, J.; Prignot, M.; Wambersie, A.

1975-01-01

A comparison of radiation dosimetry performed between Edinburgh and Louvain using the FeSO 4 system, was reported. The procedure adopted provided comparisons both of solution response and of spectrophotometer calibration, and also provided a comparison of ionization dosimetry and irradiation techniques at the two centres. Therefore dosimeter solutions were prepared in both centres, FeSO 4 samples were irradiated either in Edinburgh (4 MV X-rays) or in Louvain ( 60 Co), finally optical densities were measured using the spectrophotometer of either centre. For these different comparisons, the samples were transported once of twice. An agreement between the two centres better than 1% was observed, both for ionization dosimetry and irradiation techniques and for spectrophotometer calibration. The ratio of Louvain to Edinburgh solution response was found close to 1 (0.998+-0.004). However, a previous comparison showed a discrepancy of 2% which illustrates the care needed in checking the purity of the solution components and mainly of the distilled water

Surface roughness and gloss study of prints: application of specular reflection at near infrared

International Nuclear Information System (INIS)

Silfsten, P; Dutta, R; Pääkkönen, P; Peiponen, K-E; Tåg, C-M; Gane, P A C

2012-01-01

Absolute reflectance data were measured with a spectrophotometer in the visible and near infrared (NIR) spectral range. The specular reflectance data in the NIR were used for the assessment of the surface roughness of magenta, yellow, cyan and black prints on paper. In addition, surface roughness data obtained from the prints with a mechanical diamond stylus, an optical profiling system and the spectrophotometer are compared with each other. The surface roughness obtained with the aid of the spectrophotometer data suggests a smoother surface than when measured with the diamond stylus and the optical profiling system. The gloss of the prints can be obtained from the absolute specular reflectance spectra in the spectral region of visible light. It is shown that specular reflection data at a fixed wavelength in the NIR are useful also in the interpretation of gloss in the visible spectral range, but using an unconventional grazing angle of incidence. (paper)

Data acquisition system for electronic paramagnetic resonance spectrophotometer

International Nuclear Information System (INIS)

Pena Eguiluz, R.

1992-01-01

In the Atomic and Molecular Physics Laboratory at the Physics Department of the Instituto Nacional de Investigaciones Nucleares (ININ), there is in operation an electronic paramagnetic resonance spectrometer (EPR). This equipment is utilized for determine, the distribution of the absorbed energy intensity for a sample of paramagnetic substance by means of the study and analysis of its emission lines spectrum. The useful information is provided as a graphic result showing the spectrum corresponding to the analyzed sample. In similar devices like this, the researchers problem, trying to get the important information, is a hard and imprecise work, thus, this process of find the ordinate magnitudes of a approximately two hundred points, equal spaced in the spectrum, is carried out completely by hand. After this, the information is captured and processed in a personal computer. As a solution for this problem, an interface in both aspects, hardware and software adaptable to a personal computer, was designed and constructed. This interface is able to: a) To get and digitized the analogical signal, that represents the corresponding spectrum curve. b) It stores the digitized information in files and c) It displays in graphic mode the stored data, and then these are normalized in order to be transferred to a statistics and analytical software packets (Author)

Spec UV-Vis: An Ultraviolet-Visible Spectrophotometer Simulation

Science.gov (United States)

Papadopoulos, N.; Limniou, Maria; Koklamanis, Giannis; Tsarouxas, Apostolos; Roilidis, Mpampis; Bigger, Stephen W.

2001-11-01

The software and its accompanying manual can be used to illustrate the recording of an absorption spectrum and the Beer-Lambert law (5-7) as well as various aspects of acid-base indicators such as the spectrophotometric determination of pKa (8), the isosbestic point (6, 9), and distribution diagrams (10, 11). Literature Cited Shiowatana, J. J. Chem. Educ. 1997, 74, 730. Altemose, I. R. J. Chem. Educ. 1986, 63, A216, A262. Piepmeier, E. H. J. Chem. Educ. 1973, 50, 640. Lott, P. F. J. Chem. Educ. 1968, 45, A89, A169, A182, A273. Skoog, D. A.; West, D. M.; Holler, F. J. Fundamentals of Analytical Chemistry, 7th ed.; Saunders College Publishing: Fort Worth, TX, 1996, Chapters 22-24. Christian, G. D. Analytical Chemistry, 5th ed.; Wiley: New York, 1994; Chapter 14. Kennedy, J. H. Analytical Chemistry--Principles, 2nd ed.; Saunders College Publishing: New York, 1990; Chapters 11,12. Patterson, G. S. J. Chem. Educ. 1999, 76, 395. Harris, D. C. Quantitative Chemical Analysis, 5th ed.; Freeman: New York, 1997; Chapters 19, 20. Butler, J. N. Ionic Equilibrium--A Mathematical Approach; Addison-Wesley: Reading, MA, 1964; Chapter 5. Sawyer, C. A.; McCarty, P. L.; Parkin, G. F. Chemistry for Environmental Engineering, 4th ed.; McGraw-Hill: Singapore, 1994; Chapter 4.

Installation Restoration Program. Remedial Investigation Report. Minnesota Air National Guard Base Duluth International Airport, Duluth, Minnesota. Volume 4

Science.gov (United States)

1990-01-01

DATA job No.: OROOl Calibration Date: 8-19-88 Instrument I.D.: Perkin Elmer 257 Client: ES Oak Ridge Grating Infrared Spectrophotometer Attn: Bill...ilh (2 2 ___ UPPER I LIMIT__ I/ LOWER I0 I 9 I LIMIT_ I -00 I o0 WW2 1EPA SAMPLE] I No. I I I---. ...I I .. .. - ==== =---I 01- J ox.9oJ wqIJ~%o S... Infrared Spectrophotometer Attn: Bill Hayden Address: 710 S. Illinois Avenue Unit: mg/L Suite F-103 Date Reported: 11-09-88 Oak Ridge, Tn. 37830 R

Usefulness of hemocytometer as a counting chamber in a computer assisted sperm analyzer (CASA)

Science.gov (United States)

Eljarah, A.; Chandler, J.; Jenkins, J.A.; Chenevert, J.; Alcanal, A.

2013-01-01

Several methods are used to determine sperm cell concentration, such as the haemocytometer, spectrophotometer, electronic cell counter and computer-assisted semen analysers (CASA). The utility of CASA systems has been limited due to the lack of characterization of individual systems and the absence of standardization among laboratories. The aims of this study were to: 1) validate and establish setup conditions for the CASA system utilizing the haemocytometer as a counting chamber, and 2) compare the different methods used for the determination of sperm cell concentration in bull semen. Two ejaculates were collected and the sperm cell concentration was determined using spectrophotometer and haemocytometer. For the Hamilton-Thorn method, the haemocytometer was used as a counting chamber. Sperm concentration was determined three times per ejaculate samples. A difference (P 0.05) or between the haemocytometer count and the spectrophotometer. Based on the results of this study, we concluded that the haemocytometer can be used in computerized semen analysis systems as a substitute for the commercially available disposable counting chambers, therefore avoiding disadvantageous high costs and slower procedures.

Characterization of potassium dichromate solutions for spectrophotometercalibration

Science.gov (United States)

Conceição, F. C.; Silva, E. M.; Gomes, J. F. S.; Borges, P. P.

2018-03-01

Spectrophotometric analysis in the ultraviolet (UV) region is used in the determination of several quantitative and qualitative parameters. For ensuring reliability of the analyses performed on the spectrophotometers, verification / calibration of the equipment must be performed periodically using certified reference materials (CRMs). This work presents the characterization stage needed for producing this CRM. The property value characterized was the absorbance for the wavelengths in the UV spectral regions. This CRM will contribute to guarantee the accuracy and linearity of the absorbance scale to the spectrophotometers, through which analytical measurement results will be provided with metrological traceability.

Feasibility study for automating the analytical laboratories of the Chemistry Branch, National Enforcement Investigation Center, Environmental Protection Agency

International Nuclear Information System (INIS)

Morris, W.F.; Fisher, E.R.; Barton, G.W. Jr.

1978-01-01

The feasibility of automating the analytical laboratories of the Chemistry Branch of the National Enforcement Investigation Center, Environmental Protection Agency, Denver, Colorado, is explored. The goals of the chemistry laboratory are defined, and instrumental methods and other tasks to be automated are described. Five optional automation systems are proposed to meet these goals and the options are evaluated in terms of cost effectiveness and other specified criteria. The instruments to be automated include (1) a Perkin-Elmer AA spectrophotometer 403, (2) Perkin-Elmer AA spectrophotometer 306, (3) Technicon AutoAnalyzer II, (4) Mettler electronic balance, and a (5) Jarrell-Ash ICP emission spectrometer

Spectrophotometry with optical fibers applied to nuclear product processing

International Nuclear Information System (INIS)

Boisde, G.; Perez, J.J.; Velluet, M.T.; Jeunhomme, L.B.

1988-01-01

Absorption spectrophotometry is widely used in laboratories for composition analysis and quality control of chemical processes. Using optical fibers for transmitting the light between the instrument and the process line allows to improve the safety and productivity of chemical processes, thanks to real time measurements. Such applications have been developed since 1975 in CEA for the monitoring of nuclear products. This has led to the development of fibers, measurement cells, and optical feedthrough sustaining high radiation doses, of fiber/spectrophotometer couplers, and finally of a photodiode array spectrophotometer optimized for being used together with optical fibers [fr

At-line cotton color measurements by portable color spectrophotometers

Science.gov (United States)

As a result of reports of cotton bales that had significant color changes from their initial Uster® High Volume Instrument (HVI™) color measurements, a program was implemented to measure cotton fiber color (Rd, +b) at-line in remote locations (warehouse, mill, etc.). The measurement of cotton fiber...

Measurements of SO2 in the Mount St. Helens debris

International Nuclear Information System (INIS)

Kerr, J.B.; Evans, F.J.; Mateer, C.L.

1982-01-01

Routine measurements of ozone and SO 2 are made with the Dobson and Brewer spectrophotometers at the Atmospheric Environment Service in Downsview Ontario. On May 20 and 21, 1980, large values of column SO 2 were observed with both spectrophotometers at the time of passage of the Mount St. Helens debris. Enhanced SO 2 values were first observed at 1800Z on May 20. The maximum column amount of SO 2 measured was 0.06 cm at 2200 Z. On May 21, SO 2 values slowly decreased from 0.03 cm at 1100 Z cm to 0.01 cm at 2000Z. Typical SO 2 amounts due to pollution at the Downsview site are approximately 0.003 to 0.005 cm. At the same time of maximum SO 2 enhancement, both Dobson and Brewer spectrophotometers measured a 0.040 cm decrease of total ozone. It is not clear whether the decrease of total ozone was caused by the volcanic cloud or natural ozone variability. Air mass trajectories indicate that the altitude of the debris cloud, which passed over Downsview at the time, was between 10 km and 12 km

The effect of different molarities of precursor Zn(NO3)2.6H2O to the growth of ZnO by solution-immersion deposited on ZnO seeded template

International Nuclear Information System (INIS)

Afaah, A N; Asib, N A M; Aadila, A; Eswar, K A; Mahmud, M R; Khusaimi, Z; Alrokayan, Salman A H; Khan, Haseeb A; Mohamed, R; Rusop, M

2015-01-01

ZnO films were grown on glass substrates by mist-atomization, with the growth temperature of 300 °C to form ZnO seeded template. The ZnO seeded template then undergo second deposition method, which is solution-immersion method to grow ZnO on the ZnO seeded template thin film. The thin films were immersed in different molarities of starting materials; which are zinc nitrate hexahydrate and HMTA. The molarities were varied from 0.05, 0.10, 0.20 and 0.40 M. As a control to the study, the ZnO seeded template which undergoes mist-atomization only, denoted as MA only is prepared for comparison studies to the other samples. The properties of the products were examined by photoluminescence (PL) spectrophotometer, Raman spectrophotometer, and ultraviolet-visible (UV-Vis) spectrophotometer. From the PL measurement, it shows that 0.40 M sample have highest UV emission and from Raman measurements, it was found that the sample immersed in 0.40 M precursor have high crystal quality. From UV-Vis measurements, sharp UV emission at ∼378 nm is observed and 0.40 M ZnO thin film shows a better absorption properties. (paper)

Size dependent photoluminescence property of hydrothermally synthesized crystalline carbon quantum dots

Energy Technology Data Exchange (ETDEWEB)

Sarkar, S.; Banerjee, D.; Ghorai, U.K.; Das, N.S. [School of Material Science and Nanotechnology Jadavpur University, Kolkata 700032 (India); Chattopadhyay, K.K., E-mail: kalyan_chattopadhyay@yahoo.com [School of Material Science and Nanotechnology Jadavpur University, Kolkata 700032 (India); Thin Film and NanoScience Laboratory, Department of Physics, Jadavpur University, Kolkata 700032 (India)

2016-10-15

In this work, simple hydrothermal synthesis of water soluble Carbon quantum dots (CQDs) of different sizes has been reported. The effect of synthesis temperature and synthesis time on the particle size has also been shown. The structures of all the as-prepared samples were studied by field emission scanning electron microscope and high resolution transmission electron microscope. Fourier transformed infrared spectrophotometer analyzes the different bonding present in the sample whereas Raman spectrophotometer quantifies the hybridization state of the prepared samples. UV–vis spectrophotometer gives the variation of absorbance of all the samples with wavelength. Dynamic light scattering study shows the variation of particle size with deposition condition and corresponding zeta potential gives the idea about the stability of the CQD solutions. The photoluminescence (PL) properties of the as prepared CQDs were also studied in detail. It is noticed that with the increase of excitation wavelength, the PL emissions for the different samples were red shifted. The results have been explained in terms of the excitation dependent emission, variations in size of the CQD and presence of different functional groups on the surface of CQDs.

Size dependent photoluminescence property of hydrothermally synthesized crystalline carbon quantum dots

International Nuclear Information System (INIS)

Sarkar, S.; Banerjee, D.; Ghorai, U.K.; Das, N.S.; Chattopadhyay, K.K.

2016-01-01

In this work, simple hydrothermal synthesis of water soluble Carbon quantum dots (CQDs) of different sizes has been reported. The effect of synthesis temperature and synthesis time on the particle size has also been shown. The structures of all the as-prepared samples were studied by field emission scanning electron microscope and high resolution transmission electron microscope. Fourier transformed infrared spectrophotometer analyzes the different bonding present in the sample whereas Raman spectrophotometer quantifies the hybridization state of the prepared samples. UV–vis spectrophotometer gives the variation of absorbance of all the samples with wavelength. Dynamic light scattering study shows the variation of particle size with deposition condition and corresponding zeta potential gives the idea about the stability of the CQD solutions. The photoluminescence (PL) properties of the as prepared CQDs were also studied in detail. It is noticed that with the increase of excitation wavelength, the PL emissions for the different samples were red shifted. The results have been explained in terms of the excitation dependent emission, variations in size of the CQD and presence of different functional groups on the surface of CQDs.

Synthesis of CdSe-TiO_2 Photocatalyst and Their Enhanced Photocatalytic Activities under UV and Visible Light

International Nuclear Information System (INIS)

Lim, Chang Sung; Chen, Ming Liang; Oh, Won Chun

2011-01-01

In this study, CdSe-TiO_2 photocatalyst were synthesized by a facile solvothermal method and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and UV-vis diffuse reflectance spectrophotometer. The photocatalytic activity was investigated by degrading methylene blue (MB) in aqueous solution under irradiation of UV light as well as visible light. The absorbance of degraded MB solution was determined by UV-vis spectrophotometer. The results revealed that the CdSe- TiO_2 photocatalyst exhibited much higher photocatalytic activity than TiO_2 both under irradiation of UV light as well as visible light

Standardization of fertilization protocols for the European eel, Anguilla anguilla

DEFF Research Database (Denmark)

Butts, Ian; Sørensen, Sune Riis; Politis, Sebastian Nikitas

2014-01-01

of this research were to provide a rapid, accurate and precise method to quantify sperm density by examining the relationship between sperm density and absorbance by use of a spectrophotometer, determine the optimal number of sperm required to fertilize eggs in a controlled setting, and explore how long eggs...... are receptive to fertilization post-stripping. Mean sperm density and absorbance at 350nm were 1.54e+10±4.95e+9sperm/mL and 1.91±0.22nm, respectively. Regression analysis demonstrated a highly significant positive relationship between sperm density and absorbance using a spectrophotometer at 350nm (R2=0.94, p

A novel system for plutonium spectrophotometry using a modified La Calhene container

International Nuclear Information System (INIS)

Savage, D.J.; MacDonald, A.

1980-02-01

A specially modified La Calhene container is described which simplifies spectrophotometric measurements on plutonium solutions without requiring a dedicated specially modified spectrophotometer. (author)

Proximate, Mineral and Phytochemical Composition of Dioscorea ...

African Journals Online (AJOL)

ADOWIE PERE

Keywords: Dioscorea dumetorum, proximate composition, mineral analysis, phytochemical screening ... were analyzed using atomic absorption ... determined using a Hack Dr/200 Spectrophotometer. ... Lead Acetate. +. +. + .... cosmetics.

7 CFR 353.9 - Standards for accreditation of non-government facilities to perform laboratory seed health...

Science.gov (United States)

2010-01-01

... seed requires a stereo microscope. Visual examination of tissue requires a compound light microscope... equipment; fluorescent microscopes; plate readers; spectrophotometers; and the appropriate assay materials...

137Cs source dose distribution using the Fricke Xylenol Gel dosimetry

International Nuclear Information System (INIS)

Sato, R.; De Almeida, A.; Moreira, M.V.

2009-01-01

Dosimetric measurements close to radioisotope sources, such as those used in brachytherapy, require high spatial resolution to avoid incorrect results in the steep dose gradient region. In this work the Fricke Xylenol Gel dosimeter was used to obtain the spatial dose distribution. The readings from a 137 Cs source were performed using two methods, visible spectrophotometer and CCD camera images. Good agreement with the Sievert summation method was found for the transversal axis dose profile within uncertainties of 4% and 5%, for the spectrophotometer and CCD camera respectively. Our results show that the dosimeter is adequate for brachytherapy dosimetry and, owing to its relatively fast and easy preparation and reading, it is recommended for quality control in brachytherapy applications.

Standard test method for color and color difference of whitewares by abriged spectrophotometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

2001-01-01

1.1 This test method describes the instrumental measurement of the reflection properties and color of ceramic glazes and other whitewares by the use of a spectrophotometer or spectrocolorimeter with a hemispherical optical measuring system, such as an integrating sphere. 1.2 The test method is suitable for use with most specimens having an exterior flat surface large enough to cover the spectrophotometer sample port. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

evaluation of pawpaw leaves extract as anti-corrosion agent

African Journals Online (AJOL)

user

2 DEPARTMENT OF CHEMICAL ENGINEERING, NNAMDI AZIKIWE UNIVERSITY, AWKA ... and corrosion product were analyzed using Fourier transform infrared spectrophotometer (FTIR). ... They are used as reaction vessels, pipes,.

Hand-Held Photometer for Instant On-Spot Quantification of Nucleic Acids, Proteins, and Cells.

Science.gov (United States)

Li, Shi-Hao; Jain, Abhinav; Tscharntke, Timo; Arnold, Tobias; Trau, Dieter W

2018-02-20

This paper presents a novel hand-held photometer, termed "Photopette", for on-spot absorbance measurements of biochemical analytes. The Photopette is a multicomponent, highly portable device with an overall weight of 160 g, which fits within 202 mm × 47 mm × 42 mm. Designed in the form factor of a micropipette, Photopette integrates a photodiode detector with light emitting diodes (LEDs) to form a highly customizable photometer which supports a wide variety of applications within the wavelengths between 260 and 1050 nm. A dual-purpose disposable reflective tip was designed to act as a sample holder and a light-reflecting system, which is in stark contrast to the operation of mainstream spectrophotometers and photometers. Small volume analytes may be measured with low sample loss using this proprietary CuveTip. A user-friendly software application running on smart devices was developed to control and read the values from Photopette via a low-energy Bluetooth link. This one-step strategy allows measurements on-spot without sample transfer, minimizing cross-contamination and human error. The results reported in this paper demonstrate Photopette's great potential to quantify DNA, direct protein, and cell density directly within the laminar flow hood. Results are compared with a Nanodrop 2000c spectrophotometer, a mainstream spectrophotometer for small-volume measurements.

Rapid identification of the medicinal plant Taraxacum formosanum ...

African Journals Online (AJOL)

Administrator

2011-06-06

Jun 6, 2011 ... 4Department of Safety, Health and Environmental Engineering, Mingchi University of Technology, ... some disadvantages, such as their low reproducibility ... determined by spectrophotometer (NanoVue™, GE Healthcare,.

An Automatic System for Determining Solar Absorptance and Thermal Emittance of Surfaces from Spectral Normal Reflectance Measurements

National Research Council Canada - National Science Library

Teichman, Louis

1965-01-01

.... The system consists of two spectrophotometers used to make optical reflectance measurements, electronic digitizing equipment to record the data, and a high-speed electronic computer to calculate the desired results...

Determination of hydrazine in third loops of China experimental fast reactor by spectrophotometry

International Nuclear Information System (INIS)

Huang Wenjie; Wang Mi; Gao Yaopeng; Xie Chun; Yu Xiaochen

2013-01-01

The method for the determination of hydrazine by Uv-vis spectrophotometer was proposed. The coloration conditions and instrument parameters were also optimized. In HCl, hydrazine formed a yellow azine with para-dimethyl aminobenzaldehyde ((CH 3 ) 2 NC 6 H 4 CHO), and then determined by spectrophotometer. The complex's maximum absorption was exhibited at 458 nm. The coloration effect was excellent in conditions of 1% HCl, 10 mL para-dimethyl aminobenzaldehyde and 10 minutes' developing time. A good liner relationship was obtained in the range of 5∼200 μg/L, and the recovery was (101.1±1.9)%. This method was used in the third loop of China experimental fast reactor with satisfactory results. (authors)

Bias in the absorption coefficient determination of a fluorescent dye, standard reference material 1932 fluorescein solution

International Nuclear Information System (INIS)

DeRose, Paul C.; Kramer, Gary W.

2005-01-01

The absorption coefficient of standard reference material[registered] (SRM[registered]) 1932, fluorescein in a borate buffer solution (pH=9.5) has been determined at λ=488.0, 490.0, 490.5 and 491.0 nm using the US national reference UV/visible spectrophotometer. The purity of the fluorescein was determined to be 97.6% as part of the certification of SRM 1932. The solution measured was prepared gravimetrically by diluting SRM 1932 with additional borate buffer. The value of the absorption coefficient was corrected for bias due to fluorescence that reaches the detector and for dye purity. Bias due to fluorescence was found to be on the order of -1% for both monochromatic and polychromatic (e.g., diode-array based) spectrophotometers

Diffusion of Vitamin B12 Across a Mesoporous Metal Organic Framework

Directory of Open Access Journals (Sweden)

Veronica Valencia

2013-01-01

Full Text Available We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water at 2 different temperatures (room temperature and 37°C by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion for this 2-phase system using Fick’s laws of diffusion.

Layered zinc hydroxide–ibuprofen nanohybrids: synthesis and ...

Indian Academy of Sciences (India)

The nonsteroidal anti-inflammatory drug (NSAID), ibuprofen (IBU) anion, was intercalated into the layered zinc ... surface morphology, Fourier transform infrared (FTIR) spectrophotometer to study the chemical interactions and ..... J. Food Sci.

Fabry-Perot observations of [FeX] in the Cygnus Loop and IC443

International Nuclear Information System (INIS)

Ballet, J.; Rothenflug, R.; Soutoul, A.; Caplan, J.

1988-01-01

The authors present the first results of an observational program of SNRs in the coronal lines of [FeX] and [FeXIV] using Fabry--Perot spectrophotometer. These support previously published brightnesses

Effects of ad libitum and restricted diets in different feeding regimes ...

African Journals Online (AJOL)

WJ

Bomb Calorimeter and starch according to the AOAC (1984) procedure. ... the Perkin Elmer Atomic Spectrophotometer-2380 (Giron, 1973). ..... changes in ingredients, making it difficult to distinguish ingredient effects from energy effects.

Effect of Temperature towards RNA Concentration: Quantitative Investigation with Spectrophotometer

Directory of Open Access Journals (Sweden)

Feby Fariska Savira

2016-06-01

Full Text Available Ribonucleic acid (RNA is a thermodynamically unstable molecule. The way RNA samples are preserved is critical to maintain maximum yield and quality, therefore it is useful for molecular analysis such as real time- PCR. There are many contradictions and variations regarding the temperature for RNA storage. The aim of this study is to find the ideal temperature to store RNA among -80o C, -20o C and 4oC by determining changes in RNA concentration over two weeks of storage time. The liver of eight rats was divided into three groups, weighing from 25-26 μg. Samples were homogenized, isolated and stored in -80oC, -20oC and 4oC freezers. Absorbance was measured with spectrophotometry at 260 and 280 nm to determine the concentration of RNA. There was no significant difference in the concentration of RNA samples stored in all temperatures after two weeks, both experimentally and statistically (Kruskal-Wallis, -80oC p=0.949; -20oC p=0.885; 4oC p=0.935. In conclusion, RNA can be stored in -80oC, -20oC and 4oC for two weeks without quantity reduction. Longer duration of study and RNA quality analysis is recommended to check for RNA degradation. Keywords: RNA, temperature, concentration, storage, spectrophotometry Efek Suhu terhadap Konsentrasi RNA: Investigasi Kuantitatif dengan Spektrofotometer Abstrak Ribonucleic acid (RNA adalah molekul yang tidak stabil secara termodinamik. Cara penyimpanan RNA sangat kritis untuk menjaga kuantitas dan kualitasnya agar dapat digunakan untuk analisis molekuler seperti real time-PCR. Tujuan penelitian ini adalah mengetahui suhu ideal penyimpanan RNA di antara -80oC, -20oC dan 4oC dengan melihat perubahan pada konsentrasi RNA selama dua minggu masa penyimpanan. Delapan hati tikus dibagi menjadi tiga kelompok dengan berat sampel 25-26 μg. Sampel hati dihomogenisasi dan diisolasi, lalu disimpan pada suhu -80oC, -20oC and 4oC. Absorbansi diukur dengan spektrofotometri pada gelombang cahaya 260 dan 280 nm untuk mendapatkan konsentrasi RNA. Tidak ditemukan perbedaan bermakna antara konsentrasi RNA dengan ketiga suhu penyimpanan selama dua minggu, baik secara eksperimental maupun secara statistik (Kruskal-Wallis, -80oC p=0,949; -20oC p=0,885; 4oC p=0,935. Disimpulkan bahwa RNA dapat disimpan pada suhu -80oC, -20oC dan 4oC selama dua minggu tanpa perubahan kuantitas. Durasi percobaan sebaiknya diperpanjang dan analisis kualitas RNA dapat dilakukan untuk melihat apablia ada degradasi terhadap RNA. Kata kunci: RNA, suhu, konsentrasi, penyimpanan, spektrofotometri Normal 0 false false false IN X-NONE X-NONE

Preliminary assessments of portable color spectrophotometer measurements of cotton color

Science.gov (United States)

Cotton in the U.S. is classified for color with the Uster® High Volume Instrument (HVI), using the parameters Rd (diffuse reflectance) and +b (yellowness). It has been reported that some cotton bales, especially those transported overseas, appear to have changed significantly in color from their in...

Minimization of operational impacts on spectrophotometer color measurements for cotton

Science.gov (United States)

A key cotton quality and processing property that is gaining increasing importance is the color of the cotton. Cotton fiber in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), using the parameters Rd and +b. Rd and +b are specific to cotton fiber and are not typical ...

Fiber sample presentation system for spectrophotometer cotton fiber color measurements

Science.gov (United States)

The Uster® High Volume Instrument (HVI) is used to class U.S. cotton for fiber color, yielding the industry accepted, cotton-specific color parameters Rd and +b. The HVI examines a 9 square inch fiber sample, and it is also used to test large AMS standard cotton “biscuits” or rectangles. Much inte...

Rapid coagulation of polystyrene latex in a stopped-flow spectrophotometer

NARCIS (Netherlands)

Lichtenbelt, J.W.Th.; Pathmamanoharan, C.; Wiersema, P.H.

1974-01-01

With a stopped-flow method the rapid coagulation by electrolyte of several polystyrene latices is measured. By extrapolating back to zero time the initial process of two single particles forming a doublet is observed. We find an average rate constant ifk11 = 6.0 × 10−12 p−1 cm3 sec su−1 at 20°C,

IMPROVED SPECTROPHOTOMETER FIBER SAMPLING SYSTEM FOR COTTON FIBER COLOR MEASUREMENTS

Science.gov (United States)

Cotton in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), and the parameters Rd and +b are used to designate color grades for cotton fiber. However, Rd and +b are cotton-specific color parameters, and the need existed to demonstrate the relationships of Rd and +b to...

The effect of parity on maternal body mass index, plasma mineral ...

African Journals Online (AJOL)

each subject. Blood lead, plasma copper, iron and zinc were determined using atomic absorption spectrophotometer. .... logical parameters, essential minerals status and blood lead of ..... and its interaction with some essential metals among.

Neonatal mortality of pigs in Nsukka, Southeast Nigeria

African Journals Online (AJOL)

Dr Abonyi

2012-08-23

Aug 23, 2012 ... tials for optimum profit making. Unfortunately, this is .... energy was determined by Gallenkamp ballistic bomb calorimeter; crude protein was ... and phosphorus were determined using the atomic absorption spectrophotometer ...

HEALTH RISK ASSESSMENT OF HEAVY METALS VIA ...

African Journals Online (AJOL)

emissions from the rapidly expanding industrial areas, mine tailings, disposal of .... determined by flame atomic absorption spectrophotometer (FAAS) that uses ... Validation of the analytical method using water, soil and vegetable reference ...

Spectrophotometric studies of transcurium element halides and oxyhalides in the solid state

International Nuclear Information System (INIS)

Young, J.P.; Haire, R.G.; Fellows, R. L.; Peterson, J.R.

1978-01-01

The present state of a microscale spectrophotometric technique is described. The application of spectrophotometry to transcurium elements (Bk, Cf, Es) requires some rather specialized microtechniques for the following reasons: only small amounts of these elements are available; their radioactivity makes the use of μg-sized samples desirable; and spectral study of solids requires thin samples. A schematic diagram of the microscope-spectrophotometer used for spectrophotometric study of the transcurium element compounds is shown. The spectrophotometer, of local design, consists of two microscopes equipped with Cassegrainian reflecting microscope objective lenses, a quartz field lens, and a Jarrell Ash 1/2 meter scanning monochromator equipped with a 1180 line/mm grating blazed at 4000 A. The photomultiplier used in this system is an S-1 type RCA 7102 operated at approximately -50 deg C. This grating-photomultiplier combination provides a continuous response free of discontinuities over the useful wavelength range of the system from 3000 to 11 000 A. The microscope-spectrophotometer is a single beam instrument. Each spectral trace is registered as photomultiplier current on a strip chart recorder. In order to obtain true absorption spectra, however, the output from the photometer is also simultaneously digitized for on-line processing. The unique advantages of applying both spectrophotometric and X-ray powder diffraction methods on the sample, in order to identify and characterize newly synthesized compounds, are also discussed. (T.G.)

Characterization of beta radiation fields using radiochromic films

International Nuclear Information System (INIS)

Benavente, Jhonny A.; Silva, Teogenes A. da

2011-01-01

The objective of this work was to study the response of radiochromic films for beta radiation fields in terms of absorbed dose. The reliability of the EBT model Gafchromic radiochromic film was studied. A 9800 XL model Microtek, transmission scanner, a 369 model X-Rite optical densitometer and a Mini 1240 Shimadzu UV spectrophotometer were used for measurement comparisons. Calibration of the three systems was done with irradiated samples of radiochromic films with 0.1; 0.3; 0.5; 0.8; 1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.5 e 5.0 Gy in beta radiation field from a Sr-90/Y-90 source. Calibration was performed by establishing a correlation between the absorbed dose values and the corresponding radiochromic responses. Results showed significant differences in the absorbed dose values obtained with the three methods. Absorbed dose values showed errors from 0.6 to 4.4%, 0.3 to 31.8% and 0.2 to 47.3% for the Microtek scanner, the X-Rite Densitometer and the Shimadzu spectrophotometer, respectively. Due to the easy acquisition and use for absorbed dose measurements, the densitometer and the spectrophotometer showed to be suitable techniques to evaluate radiation dose in relatively homogeneous fields. In the case of inhomogeneous fields or for a two dimension mapping of radiation fields to identify anisotropies, the scanner technique is the most recommended. (author)

Characterization of beta radiation fields using radiochromic films; Caracterizacao de campos de radiacao beta utilizando filmes radiocromicos

Energy Technology Data Exchange (ETDEWEB)

Benavente, Jhonny A.; Silva, Teogenes A. da, E-mail: jabc@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencia e Tecnologia das Radiacoes, Minerais e Materiais; Meira-Belo, Luiz C.; Reynaldo, Sibele R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

The objective of this work was to study the response of radiochromic films for beta radiation fields in terms of absorbed dose. The reliability of the EBT model Gafchromic radiochromic film was studied. A 9800 XL model Microtek, transmission scanner, a 369 model X-Rite optical densitometer and a Mini 1240 Shimadzu UV spectrophotometer were used for measurement comparisons. Calibration of the three systems was done with irradiated samples of radiochromic films with 0.1; 0.3; 0.5; 0.8; 1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.5 e 5.0 Gy in beta radiation field from a Sr-90/Y-90 source. Calibration was performed by establishing a correlation between the absorbed dose values and the corresponding radiochromic responses. Results showed significant differences in the absorbed dose values obtained with the three methods. Absorbed dose values showed errors from 0.6 to 4.4%, 0.3 to 31.8% and 0.2 to 47.3% for the Microtek scanner, the X-Rite Densitometer and the Shimadzu spectrophotometer, respectively. Due to the easy acquisition and use for absorbed dose measurements, the densitometer and the spectrophotometer showed to be suitable techniques to evaluate radiation dose in relatively homogeneous fields. In the case of inhomogeneous fields or for a two dimension mapping of radiation fields to identify anisotropies, the scanner technique is the most recommended. (author)

Determining CDOM Absorption Spectra in Diverse Aquatic Environments Using a Multiple Pathlength, Liquid Core Waveguide System

Science.gov (United States)

Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

2001-01-01

We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, aCDOM, and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values and showed a linear response across all four pathlengths. Values of aCDOM measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of aCDOM for MPLCW measurements was 0.002 - 231.5 m-1. At low CDOM concentrations spectrophotometric aCDOM were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples.

Demonstration of physical phenomenas and scavenging activity from d-psicose and methionine maillard reaction products

Directory of Open Access Journals (Sweden)

Arum Tiyas Suminar

2017-01-01

Full Text Available Maillard reaction has been well understood as a non-enzymatic reaction between reducing sugars and amino acids to generate the Maillard reaction products (MRPs. This study is aimed to demonstrate the browning intensity, color development, spectra measurements, scavenging activity, and the correlation between browning intensity and scavenging activity of the MRPs generated from D-Psicose and Methionine (Psi-Met at 50℃. The browning intensity of MRPs was investigated based on the absorbance using spectrophotometer at 420 nm, the color development was observed using digital colorimeter to gained L*a*b* value then calculated as browning index, the spectra development was analyzed using spectrophotometer at 190 - 750 nm, and the scavenging activity was determined with ABTS method using spectrophotometer at 734 nm. The browning intensity, color development, and scavenging activity were improved along with the increase in heating process. Based on spectra analysis, MRPs from Psi-Met was initially detected at 21 h and Psi at 24 h of heating treatment, which indicating that Psi-Met have faster and better reaction than Psi during heating process. Positive non-linear and significant correlation between browning intensity and scavenging activity were assigned. This finding may provide beneficial information of D-psicose and MRPs to the next scientific research and to the food industries which applies MRPs in their products.

[Preliminary evaluation on self-developed dentin porcelain color prediction system].

Science.gov (United States)

Chen, L; Lu, C; Li, X L; Zhu, X M; Zhang, S; Tan, J G

2016-09-01

To apply the self-developed dentin porcelain color prediction system in the fabrication of porcelain-fused-to-metal-crown(PFMC), and to evaluate its accuracy in color-matching. Twenty upper central incisors were recruited according to preset criteria, and three PFMC were made for each tooth using three shade-matching techniques. Group A: PFMC were made according to the result of visual color selection; Group B: an spectrophotometer-based color-matching technique was used; Group C: PFMC were fabricated with dentin porcelain powder calculated by the prediction system according to the L(*), a(*), b(*) value measured by a spectrophotometer. Color differences(ΔE) (measured by spectrophotometer) of three groups of crowns were calculated in the cervical, middle, and incisal regions. The results were analyzed using one-way ANOVA. Mean color differences in body regions were: Group A: 3.53±1.80, Group B: 2.86±1.63, Group C: 3.77±1.40(P>0.05), and those in incisal regions were: Group A: 2.70 ± 1.13, Group B: 2.80 ± 0.90, Group C: 3.04 ± 1.03(P>0.05). In cervical region, Group C had greater color difference than Group B(2.78±1.14)(P0.05). PFMC fabricated using self-developed dentin porcelain color prediction system had similar color matching compared with conventional and instrument-based methods.

Estimation of Theaflavins (TF) and Thearubigins (TR) Ratio in Black Tea Liquor Using Electronic Vision System

Science.gov (United States)

Akuli, Amitava; Pal, Abhra; Ghosh, Arunangshu; Bhattacharyya, Nabarun; Bandhopadhyya, Rajib; Tamuly, Pradip; Gogoi, Nagen

2011-09-01

Quality of black tea is generally assessed using organoleptic tests by professional tea tasters. They determine the quality of black tea based on its appearance (in dry condition and during liquor formation), aroma and taste. Variation in the above parameters is actually contributed by a number of chemical compounds like, Theaflavins (TF), Thearubigins (TR), Caffeine, Linalool, Geraniol etc. Among the above, TF and TR are the most important chemical compounds, which actually contribute to the formation of taste, colour and brightness in tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer instrument. But, the analysis technique undergoes a rigorous and time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an Electronic Vision System based on digital image processing technique has been developed. The system is faster, low cost, repeatable and can estimate the amount of TF and TR ratio for black tea liquor with accuracy. The data analysis is done using Principal Component Analysis (PCA), Multiple Linear Regression (MLR) and Multiple Discriminate Analysis (MDA). A correlation has been established between colour of tea liquor images and TF, TR ratio. This paper describes the newly developed E-Vision system, experimental methods, data analysis algorithms and finally, the performance of the E-Vision System as compared to the results of traditional spectrophotometer.

Reliability and accuracy of Crystaleye spectrophotometric system.

Science.gov (United States)

Chen, Li; Tan, Jian Guo; Zhou, Jian Feng; Yang, Xu; Du, Yang; Wang, Fang Ping

2010-01-01

to develop an in vitro shade-measuring model to evaluate the reliability and accuracy of the Crystaleye spectrophotometric system, a newly developed spectrophotometer. four shade guides, VITA Classical, VITA 3D-Master, Chromascop and Vintage Halo NCC, were measured with the Crystaleye spectrophotometer in a standardised model, ten times for 107 shade tabs. The shade-matching results and the CIE L*a*b* values of the cervical, body and incisal regions for each measurement were automatically analysed using the supporting software. Reliability and accuracy were calculated for each shade tab both in percentage and in colour difference (ΔE). Difference was analysed by one-way ANOVA in the cervical, body and incisal regions. range of reliability was 88.81% to 98.97% and 0.13 to 0.24 ΔE units, and that of accuracy was 44.05% to 91.25% and 1.03 to 1.89 ΔE units. Significant differences in reliability and accuracy were found between the body region and the cervical and incisal regions. Comparisons made among regions and shade guides revealed that evaluation in ΔE was prone to disclose the differences. measurements with the Crystaleye spectrophotometer had similar, high reliability in different shade guides and regions, indicating predictable repeated measurements. Accuracy in the body region was high and less variable compared with the cervical and incisal regions.

A comparative study on the biochemical effect of ocular and oral ...

African Journals Online (AJOL)

STORAGESEVER

2010-05-24

May 24, 2010 ... smoke (Avunduk et al., 1997) and facial cosmetics ... Ocular exposure to Cd may lead to ... atomic absorption spectrophotometer, Hitachi, Tokyo, Japan). To ... procedure involved the determination of thiobarbituric acid reactive.

Spectrophotometric Determination Of Heavy Metals In Cosmetics

African Journals Online (AJOL)

ISSN 1597-6343. Spectrophotometric Determination Of Heavy Metals In Cosmetics ... analysed using atomic absorption spectrophotometer – coupled with a hydride ... presence of arsenic (As), mercury (Hg), cadmium (Cd) and lead. (Pb) in ...

Visual evaluation of beef tenderness by using surface structural ...

African Journals Online (AJOL)

Kedibone KY. Modika

2015-08-01

Aug 1, 2015 ... The tenderisation process is estimated to begin soon after slaughter, depending .... spectrophotometer, which was used with the software package SpectraMagic NX Pro (Konica-Minolta) (CIE. 1986) at three ... probability.

Estimating Soil Bulk Density and Total Nitrogen from Catchment ...

African Journals Online (AJOL)

Bheema

The SMR analysis showed overall model coefficients of determination (R ..... Fe & Zn. SMR, stepwise multiple regression; GLM, generalized linear model; n is ... spectrophotometer, while Na and K were determined by flame photometry (Black.

Synthesis and characterization of some metal complexes of a Schiff ...

African Journals Online (AJOL)

KEY WORDS: Metal complexes, Schiff base, Ninhydrin, α,L-Alanine, .... Buck Scientific Infrared Spectrophotometer Model 500 in the range of 4000 .... Assignments based on Nakamoto [35], ν - stretching vibration, δ - bending or deformation.

A Spectrophotometric Method for the Determination of Ramipril in ...

African Journals Online (AJOL)

HP

Purpose: To develop a simple and cost effective spectrophotometer method for the determination of. ACE inhibitor ramipril in dosage forms. Methods: UV spectrophotometry was used to develop and validate a simple method .... 2003 software.

Magnetic, catalytic, EPR and electrochemical studies on binuclear ...

Indian Academy of Sciences (India)

Unknown

binuclear copper(II) complexes derived from 3,4-disubstituted phenol ... M. Avanta G.B.C., Australia atomic absorption spectrophotometer. .... hydroxide. ... in OH bridged complexes may give rise to poor ligand–metal orbital overlap. The.

Geochemical assessment of toxic metals stocking in top-soil within ...

African Journals Online (AJOL)

African Journal of Environmental Science and Technology ... Journal Home > Vol 10, No 9 (2016) >. Log in or ... All the samples were processed and extracted with nitrate acid solution and analysed using smart spectrophotometer methods.

Change in amino acids content during germination and ... - AJOL

African Journals Online (AJOL)

GREGORY

2010-08-30

Val) was the least present, while in C. anomala, .... Hitachi F-1050 fluorescence spectrophotometer (λex = 334 nm, λem. = 425 nm). The column ...... Schott and Endlicher) using enzymatic markers. Plant Genet. Res. Newslett.

Instrument calls and real-time code for laboratory automation

International Nuclear Information System (INIS)

Taber, L.; Ames, H.S.; Yamauchi, R.K.; Barton, G.W. Jr.

1978-01-01

These programs are the result of a joint Lawrence Livermore Laboratory and Environmental Protection Agency project to automate water quality laboratories. They form the interface between the analytical instruments and the BASIC language programs for data reduction and analysis. They operate on Data General NOVA 840's at Cincinnati and Chicago and on a Data General ECLIPSE C330 at Livermore. The operating system consists of unmodified RDOS, Data General's disk operating system, and Data General's multiuser BASIC modified to provide the instrument CALLs and other functions described. Instruments automated at various laboratories include Technicon AutoAnalyzers, atomic absorption spectrophotometers, total organic carbon analyzers, an emission spectrometer, an electronic balance, sample changers, and an optical spectrophotometer. Other instruments may be automated using these same CALLs, or new CALLs may be written as described

Levels of cobalt and silver in water sources in a mining area in Ghana

African Journals Online (AJOL)

underground water and river water) from a mining community in Ghana. The water samples were treated in the laboratory by acid digestion and the concentration of silver and cobalt were analysed with Atomic Absorption Spectrophotometer.

Article 4

African Journals Online (AJOL)

detection of the entirely transmitted energy simultaneously (Koenig ... are tightly bonded together with only weak bonding existing ... and then placed at the light chamber of the spectrophotometer. ... signal of Al-Mg-OH band vibrations which.

(17) ACCUMULATION OF HEAVY METAL

African Journals Online (AJOL)

Adeyinka Odunsi

Spectrophotometer (AAS) 2ID using their respective lamp and wavelengths. Calculation ... (Table 2). Concentration of heavy metals in the cassava. Lead and chromium were not significantly ..... Market basket survey for some heavy metals in ...

SELECTIVE SODIUM REMOVAL FROM LITHIUM CHLORIDE ...

African Journals Online (AJOL)

Preferred Customer

regression coefficient value of above 0.99. ... The powdered pattern of the sample was determined by X-ray ... brines and supplied by the Qinghai Lithium Co. ... Flame atomic absorption spectrophotometer (FAAS) (GBC-932 AAS, Australia).

Influence of Fatty Acid Methyl Esters on Fuel properties of Biodiesel ...

African Journals Online (AJOL)

Influence of Fatty Acid Methyl Esters on Fuel properties of Biodiesel Produced from the. Seeds Oil of Curcubita ... Gas chromatograph coupled with mass spectrophotometer (GC-MS). The results indicate ..... Chemical and physical properties of ...

glutamic acid from high-viscosity fermentation broth

African Journals Online (AJOL)

Measurement of IR spectrum was performed using an IR spectrophotometer with KBr pellet. . Results: The ... presence of carboxyl, hydroxyl, carbonyl and amide groups. Conclusion: An ... charges near neutral pH because of the ionization of ...

root extract on egg production

African Journals Online (AJOL)

2013-07-30

Jul 30, 2013 ... using a shell strength device with a spiral pressure system (Fujihara, ... spectrophotometer by the improved ABTS•+ method, as described by ..... no advantage of this attribute in characterizing eggshell colour (Li et al., 2006).

Catalytic aspects of a copper(II) complex: biological oxidase to ...

Indian Academy of Sciences (India)

BISWAJIT CHOWDHURY

2017-10-03

Oct 3, 2017 ... made with a Jasco model V-730 UV-Vis spectrophotometer. ..... Ligand-induced coordination changes ... Fet3 protein from yeast, a multinuclear copper oxidase ... of mutants of the multicopper oxidase Fet3p Biochem-.

Isolation and partial purification of lysozyme from saliva of Bali Cattle ...

African Journals Online (AJOL)

SND

2012-01-26

Jan 26, 2012 ... 2Faculty of Mathematics and Life Sciences, Mataram University, Jl. Majapahit No. ... The method adopted for isolation of the lysozyme was from Su and ... Vis spectrophotometer (Shimadzu UV-160, Japan) using a BSA.

In vitro study on biomineralization of biphasic calcium phosphate ...

Indian Academy of Sciences (India)

Chitosan, a product obtained by removal of acetyl group from chitin, is the second .... range using Nicolet Impact 400 Fourier transform infrared spectrophotometer using .... trum shows BCP is intact without disintegration. It reveals the presence ...

UV, VISIBLE AND NIR SPECTRAL ANALYSIS OF EGGSHELLS IN THE CHARADRIIDAE FAMILY OF BIRDS

Science.gov (United States)

We employed reflectance spectrophotometry to quantify color and mineral composition of eggshells from several species of the bird family Charadriidae to characterize species physiology and to distinguish nesting habitat preferences. We used a Shimadzu spectrophotometer to measur...

bioactivities of extracts, debromolaurinterol and fucosterol from ...

African Journals Online (AJOL)

Mohammed Azeemuddin

(UV-Vis spectrophotometer, model 6305, JENWAY). The absorbance of each sample which contained DPPH was ... tank, and a lamp illuminated the uncovered part to attract the ..... C. myrica and P. boryana led to isolation of a sesquiterpene.

Compostos fenólicos e atividade antimicrobiana de Myracrodruon ...

African Journals Online (AJOL)

Usuario

2012-04-20

Apr 20, 2012 ... dichlorophenoxyacetic acid (2,4-D). After inoculation, the ... spectrophotometer UV-VIS (Analyser 850M) at 760 nm, using gallic acid as standard. ... and against the following isolates of fungi: Candida albicans. ATCC14053 ...

Biochemical, nutritional and haematological implications of Telfairia ...

African Journals Online (AJOL)

GREGO

2007-04-16

Apr 16, 2007 ... rich sources of iron and essential fatty acids making it desirable as cooking oil. ... using Atomic Absorption Spectrophotometer (AAS model SP9). ... Gallenkamp ballistic bomb calorimeter (Model CBB-330-0104L). The results ...

Download this PDF file

African Journals Online (AJOL)

Department of Chemistry

spectrophotometer (PE-3300) using the hollow cathode lamps. ... The mineral content of Ficus carica is shown in Table 2. Potassium was the ... Currently, enormous amounts of food supplements are available in the market, which may be ...

Phosphate Rock Dissolution and Availability in Some Soils of Semi ...

African Journals Online (AJOL)

Fiifi Baidoo

crop production with less expensive indigenous phosphate rocks (PRs) merits the attention of ... spectrophoto-meter at 712 nm following the procedure of Murphy & Riley (1962). Laboratory analyses ..... L. M. and Goh K. M. (1989). Effects of ...

Robotic UV-Vis apparatus for long-term characterization of drug release from nanochannels

International Nuclear Information System (INIS)

Geninatti, T; Grattoni, A; Small, E

2014-01-01

Reliable monitoring of the kinetics of molecular release from drug delivery devices is crucial for their therapeutic success. Commercially available UV-Vis spectrophotometers provide reliable quantification of analyte concentrations directly correlated to the absorbance of fluids. However, they are not suitable for long-term measurements requiring high frequency of sampling from a large number of replicates and continuous fluid mixing, all of which are necessary for evaluation of drug delivery devices. To address this need, we developed a novel robotic apparatus serially connected to a commercial UV-Vis spectrophotometer. The robotic apparatus enables us to automatically and reliably acquire long-term data for up to 48 samples with high frequency of measurements and independent magnetic stirring. We equipped the robotic apparatus with independent connectors that allowed us to apply an electric potential to each sample for electrokinetic studies. The apparatus repeatability and accuracy was demonstrated in comparison to a commercial UV-Vis spectrophotometer. The system was successfully employed to characterize the diffusion kinetics of acetone and doxorubicin through nanochannel membranes (nDS) designed for long-term drug delivery. Dendritic fullerene 1 was used to show that the robotic apparatus routes the electric potential to nanochannel membranes enabling us to investigate the actively controlled release of molecules. Our results demonstrate that the robotic apparatus could widely broaden the range of applications of UV-Vis spectrophotometry, especially in the case of large sample processing and for long-term diffusive and electrokinetic studies in drug delivery. (technical design note)

An assessment of the accuracy of visual diagnosis of meconium-stained amniotic fluid

International Nuclear Information System (INIS)

Sanlialp, C.; Caglar, G.S.; Tapisiz, O.L.; Avsar, A.F.

2004-01-01

Objective: The assessment of meconium content in the amniotic fluid depends on visual observation by clinicians at the bedside. The aim of the present study was to compare visual evaluation of meconium-stained amniotic fluid with spectrophotometer evaluation. Study Design: Ten gram of meconium was added to 100 ml of amniotic fluid and mixed. The solution was serially two-fold diluted with amniotic fluid. The serially diluted tubes' absorbance spectrum was measured at 420 nm and thus a standard scale was established. Ninety five samples of meconium- stained amniotic fluid were collected from labouring women and the grade of meconium was deter- mined visually at the bedside. The samples' absorbance spectrum was measured at 420 nm and recorded. Spectrophotometer was considered gold standard and the ranges of optical density in the standard scale was used to test the accuracy of visual categorization of the samples. In the statistical analysis chi-square test was used and significance was p<0.05. Results: The accuracy rate of visual diagnosis of meconium-stained amniotic fluid were found as statistically significant (accuracy rate=54.74%, p<0.001). Visual evaluation was correct in 19.4% of thin, 53.1 % of moderate and 90.6% of thick meconium samples when examined with spectrophotometer. Conclusion: Visually diagnosed thin meconium can be moderate or thick meconium when examined objectively. The visual diagnosis at bedside is not always reliable and should be replaced with an objective method like spectrophotometry. (author)

Observation of diffusion phenomena of liquid phase with multiple components

International Nuclear Information System (INIS)

Eguchi, Wataru

1979-01-01

The diffusion phenomena of liquid phase with multiple components was directly observed, and the factors contributing to complex material transfer were investigated, comparing to the former experimental results. The most excellent method of observing the diffusion behavior of liquid phase used heretofore is to trace the time history of concentration distribution for each component in unsteady diffusion process. The method of directly observing the concentration distribution is usually classified into the analysis of diffused samples, the checking of radioactive isotope tracers, and the measurement of light refraction and transmission. The most suitable method among these is to trace this time history by utilizing the spectrophotometer of position scanning type. An improved spectrophotometer was manufactured for trial. The outline of the measuring system and the detail of the optical system of this new type spectrophotometer are explained. The resolving power for position measurement is described with the numerical calculation. As for the observation examples of the diffusion phenomena of liquid phase with multiple components, the diffusion of multiple electrolytes in aqueous solution, the observation of the material transfer phenomena accompanied by heterogeneous and single phase chemical reaction, and the observation of concentration distribution in the liquid diaphragm in a reaction absorption system are described. For each experimental item, the test apparatus, the sample material, the test process, the test results and the evaluation are explained in detail, and the diffusion phenomena of liquid phase with multiple components were pretty well elucidated. (Nakai, Y.)

A simple and low-cost biofilm quantification method using LED and CMOS image sensor.

Science.gov (United States)

Kwak, Yeon Hwa; Lee, Junhee; Lee, Junghoon; Kwak, Soo Hwan; Oh, Sangwoo; Paek, Se-Hwan; Ha, Un-Hwan; Seo, Sungkyu

2014-12-01

A novel biofilm detection platform, which consists of a cost-effective red, green, and blue light-emitting diode (RGB LED) as a light source and a lens-free CMOS image sensor as a detector, is designed. This system can measure the diffraction patterns of cells from their shadow images, and gather light absorbance information according to the concentration of biofilms through a simple image processing procedure. Compared to a bulky and expensive commercial spectrophotometer, this platform can provide accurate and reproducible biofilm concentration detection and is simple, compact, and inexpensive. Biofilms originating from various bacterial strains, including Pseudomonas aeruginosa (P. aeruginosa), were tested to demonstrate the efficacy of this new biofilm detection approach. The results were compared with the results obtained from a commercial spectrophotometer. To utilize a cost-effective light source (i.e., an LED) for biofilm detection, the illumination conditions were optimized. For accurate and reproducible biofilm detection, a simple, custom-coded image processing algorithm was developed and applied to a five-megapixel CMOS image sensor, which is a cost-effective detector. The concentration of biofilms formed by P. aeruginosa was detected and quantified by varying the indole concentration, and the results were compared with the results obtained from a commercial spectrophotometer. The correlation value of the results from those two systems was 0.981 (N = 9, P CMOS image-sensor platform. Copyright © 2014 Elsevier B.V. All rights reserved.

Screening upland rice (Oryza sativa L. ssp. indica) genotypes for salt ...

African Journals Online (AJOL)

USER

2010-07-26

Jul 26, 2010 ... lamps (TLD 36W/84, Cool White, Philips, Thailand). Fourteen-day- ... were measured using a UV-visible spectrophotometer (DR/4000,. HACH ... measuring beam of far-red light (LED source with typical peak at wavelength ...

Development of paclitaxel-loaded liposomal systems with anti-her2 ...

African Journals Online (AJOL)

Methods: Seven different liposomal systems containing PTX, or MabHer2 or a combination of .... particle distribution via the polydispersity index ... at a constant voltage of 150 V for about 3h. ... using nano-drop spectrophotometer (BioSpec-.

Metal concentration in some seaweeds of Goa (India)

Digital Repository Service at National Institute of Oceanography (India)

Agadi, V.V.; Bhosle, N.B.; Untawale, A.G.

Seventeen species of marine algae collected from five localities of Goa, were analysed for Co, Cu, Fe, Mn, Ni, Pb and Zn, using atomic absorption spectrophotometer. All the seven metals showed considerable variations in their concentration. The role...

Organic acids in the rhizosphere and root characteristics of soybean ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... taken for the estimation of arbuscular mycorrhizal fungi (AMF) infection by the method of ... of the peaks and detection was by UV–VIS spectrophotometer at a wavelength of 210 nm. Standards and calibration curves were.

Extraction and analysis of tea (Camellia sinensis) seed oil from ...

African Journals Online (AJOL)

OMONDI-GUYA

2013-02-20

Feb 20, 2013 ... spectrophotometer (Model JENWAY6705, multi-cell changer) against a blank ... All the tea seed oil extracts were golden yellow in color and liquid at .... respectively, the two being products of oxidative rancidity. (Chindo et al.

Growth in liquid media.

Science.gov (United States)

Elbing, Karen; Brent, Roger

2002-08-01

The procedure for inoculating overnight (starter) cultures of E. coli from a single colony is described along with considerations for growing larger cultures. Also included are two methods for monitoring cell growth using a spectrophotometer or a hemacytometer.

The Determination of Uranium and Trace Metal Impurities in Yellow Cake Sample by Chemical Method

International Nuclear Information System (INIS)

Busamongkol, Arporn; Rodthongkom, Chouvana

1999-01-01

The purity of uranium cake is very critical in nuclear-grade uranium (UO 2 ) and uranium hexafluoride (UF 6 ) production. The major element in yellow cake is uranium and trace metal impurities. The objective of this study is to determine uranium and 25 trace metal impurities; Aluminum, Barium, Bismuth, Calcium, Cadmium, Cobalt, Chromium, Copper, Iron, Potassium, Iithium, Magnesium, Manganese, Molybdenum, Sodium, Niobium, Nickel, Lead, Antimony, Tin, Strontium, Titanium, Vanadium, Zinc and Zirconium, Uranium is determined by Potassium dichromate titration, after solvent extraction with Cupferon in Chloroform, Trace metal impurities are determined by solvent extraction with Tributyl Phosphate in Carbon-tetrachloride ( for first 23 elements) and N-Benzoyl-N-Phenylhydroxylamine in Chloroform ( for last 2 elements), then analyzed by Atomic Absorption Spectrophotometer (AAS) compared with Inductively Couple Plasma Spectrophotometers (ICP). The accuracy and precision are studied with standard uranium octaoxide

Improved sample holders for the PMMA dosimeters

International Nuclear Information System (INIS)

Kobayashi, Toshikazu; Sone, Koji; Iso, Katsuaki

1994-01-01

PMMA dosimeters are widely used for high dose dosimetry. Dose is determined by measuring the change in optical density of the irradiated PMMA dosimeter element. Measurement precision depends on the mounting method of a dosimeter element in the sample room of a spectrophotometer. We tried to prepare three types of holders, (holders A, B and C in Figs. 1-3), according to the shape of PMMA dosimeter elements. We measured optical density of the irradiated PMMA dosimeter elements by using the three types of holders. It is revealed that the holder of the type A gives more precise results for the Red 4034 or Gammachrome YR dosimeter than that of the type B. The measurements with a spectrophotometer using the type C holder gives better results for the Red acrylic dosimeter than the case of the measurements by the exclusive reader. (author)

Gloss as an aspect of the measurement of appearance

Science.gov (United States)

Ji, Wei; Pointer, Mike R.; Luo, Ronnier M.; Dakin, John

2006-01-01

The perception and measurement of gloss is just one part of the concept of appearance measurement. We describe the comparison between data derived by 20 observers who each scaled the perceived gloss of a set of 84 neutral and colored test samples and measurements of those samples made using a glossmeter and a sphere-based spectrophotometer. With a glossmeter, the relationship between the visual-scaled data and the measured gloss values could be described by a three-part linear fit or, with a higher correlation, a cubic function. For the sphere-based spectrophotometer, the difference in the luminance factor, DeltaY, between specular-included and specular-excluded measurements, was found to give a better linear correlation with the observer-scaled data. The color of the samples did not appear to significantly change the perceived gloss of the surface.

GMJ V 12 2010.pub Final

African Journals Online (AJOL)

Dr. Annku

the ore for cosmetic purposes. Modern ... in the Arufu Lead-Zinc Mining District, Middle Benue. Trough ... Cr, As, Cd and Ag, using atomic absorption spectrophotometer (AAS). ... and the pH of both soil and water samples were also determined.

Nutritional composition, vitamins, minerals and toxic heavy metals ...

African Journals Online (AJOL)

, than retinol (0.81 mg/g). Among the macro minerals, potassium was present in high concentration (51.6 mg/g) than sodium (44.0 mg/g). The trace elements were assessed using atomic absorption spectrophotometer (AAS) and their ...

Friction stir processed Al–TiO₂ surface composites: Anodising behaviour and optical appearance

DEFF Research Database (Denmark)

Gudla, Visweswara Chakravarthy; Jensen, Flemming; Simar, Aude

2015-01-01

was investigated. Microstructural and morphological characterization was performed using scanning (SEM) and transmission electron microscopy (TEM), and X-ray diffraction (XRD). The surface appearance was analysed using an integrating sphere-spectrophotometer setup which measures the diffuse and total reflectance...

A rapid method of estimating the solar irradiance spectra with potential lighting applications

NARCIS (Netherlands)

Gao, Y.; Dong, J.; Isabella, O.; Zeman, M.; Zhang, G

2016-01-01

Diverse solar irradiance spectra can be observed under different conditions of time, date, location, weather, etc. Since the solar irradiance spectrum is required by certain scientific and engineering applications, obtaining accurate spectral data is essential. Measurements by spectrophotometers are

Antiplasmodial and larvicidal compounds of Toddalia asiatica root ...

Indian Academy of Sciences (India)

communication, we report the isolation of eight com- pounds from the ... UNICAM SP 8-150 UV/VIS spectrophotometer. Mass spectral data were obtained on a MAT 8200 A Varian. Bremen ..... the stock solutions were diluted in the media RPMI.

Characterization of Optical Attenuation by Colored Dissolved Organic Matter (CDOM) in the Red Sea

KAUST Repository

Tiwari, Surya Prakash; Kü rten, Benjamin; Jones, Burton

2016-01-01

from two different instruments (i.e. a spectrophotometer and WET Labs ac-s sensor), and assesses the variations in optical properties of CDOM in the Red Sea using data collected in 2014 and 2015. Three global inversion algorithms (Garver

glutamic acid from high-viscosity fermentation broth

African Journals Online (AJOL)

Measurement of IR spectrum was performed using an IR spectrophotometer with ... Results: The results showed that the γ-PGA yield was 35 g/L. The viscosity of ... of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), ...

Characterization of light absorption by chromophoric dissolved organic matter (CDOM) in the upper layer of the Red Sea

KAUST Repository

Kheireddine, Malika; Ouhssain, Mustapha; Calleja, Maria Ll.; Moran, Xose Anxelu G.; Sarma, Y.V.B; Tiwari, Surya Prakash; Jones, Burton

2018-01-01

distribution of the absorption coefficient of CDOM. The spectral absorption coefficients were determined from 400nm to 740nm using a WETLabs ac-s hyper-spectral spectrophotometer. In general, we found a latitudinal gradient in the CDOM absorption coefficient

Evaluation of pawpaw leaves extract as anti-corrosion agent for ...

African Journals Online (AJOL)

Pawpaw leaves extract was examined as anti-corrosion agent for aluminium in hydrochloric acid medium. The extract and corrosion product were analyzed using Fourier transform infrared spectrophotometer (FTIR). Thermometric, gravimetric, potentiodynamic polarization and scanning electron microscopic methods were ...

efficiency of wastewater treatment by a mixture of sludge

African Journals Online (AJOL)

H. Khaldi

2017-09-01

Sep 1, 2017 ... All bioreactors were illuminated with two SQI LED T8 tube green technology lamps, with a 12 h light- 12h dark cycle. ... measurements were performed using the SHIMADZU 1240 UV/VIS Spectrophotometer. In each bioreactor ...

Thermodynamics of the Rhodamine B Lactone--Zwitterion Equilibrium.

Science.gov (United States)

Hinckley, Daniel A.; Seybold, Paul G.

1987-01-01

Discusses the benefits of thermochromic transformations for studying thermodynamic properties. Describes an experiment that uses a commercially available dye, attains equilibrium rapidly, employs a simple, single-beam spectrophotometer, and is suitable for both physical chemistry and introductory chemistry laboratories. (TW)

Displacement of aqua ligands from the hydroxopentaaquarhodium ...

Indian Academy of Sciences (India)

Abstract. The kinetics of the reaction of HOBt with [Rh(H2O)5(OH)]2+ has been studied spectrophotomet- ... antitumor properties, were found to be effective as anti- ... Experimental ..... in rate may be explained based on the acid dissociation.

SphinX : A fast solar Ph otometer in X -rays

Czech Academy of Sciences Publication Activity Database

Sylwester, J.; Kuzin, S.; Kotov, Yu. D.; Fárník, František; Reale, F.

2008-01-01

Roč. 29, 1-2 (2008), s. 339-343 ISSN 0250-6335 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-rays * spectrophotometer * high time resolution Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.667, year: 2008

POLLUTION EFFECT OF FOOD AND BEVERAGES EFFLUENTS ...

African Journals Online (AJOL)

Preferred Customer

UV-Visible spectrophotometer (model CE 2501, 2000 series). Nickel ..... The level of nitrate in the effluent varied between 32.1 mg/L and 58.4 mg/L. These levels ..... Institute of Social and Economic Research, Ibadan, Nigeria; 1986; p 234. 9.

preliminary investigation of a colouring matter extract from sorghum

African Journals Online (AJOL)

Umar Ali

2012-03-21

Mar 21, 2012 ... used particularly for goat-skin leather in Nigeria, but also for mats, textiles, ... xJenway3320 and. UV/visible Spectrophotometer model Pye Unicam UV- ... The dyed fabric samples were tested for light fastness along with eight ...

Temperature dependence of gafchromic MD-55 dosimeter

International Nuclear Information System (INIS)

Klassen, Norman V.; Zwan, Len van der; Cygler, Joanna

1997-01-01

Objective: Gafchromic MD-55 is a fairly new, thin film dosimeter that develops a blue color (λ max = 676 nm) when irradiated with ionizing radiation. The increase in absorbance is nearly proportional to the absorbed dose. MD-55 can be used for high precision dosimetry if care is taken to assure reproducible film orientation in the spectrophotometer as well as temperature control during both irradiation and reading. In order to achieve the maximum sensitivity of this dosimeter the readings of the optical density should be taken at λ max . It was reported for another type of Gafchromic film (DM-1260), that both λ max and ε max decrease with an increase in the temperature of the spectrophotometer. The purpose of this study was to characterize the reading temperature dependence of the new type of Gafchromic film available on the market and to find optimal conditions for using it for high precision dosimetry. Materials and Methods: Irradiations were carried out using 60 Co gamma rays from an Eldorado irradiator. The dosimeters were sandwiched in a lucite phantom with 4.4 mm build-up and irradiated in the center of a 10 cm x 10 cm field at 1 meter from the source. The temperature during irradiations was 22 deg. C. The dose rate was about 0.68 Gy/min. Measurements of optical density were made using a Cary 210 spectrophotometer. A bandpass of 3.5 nm was used. The temperature of the baseplate of the sample holder was regulated to +/-0.05 deg. C and measured by a probe lying on the baseplate. In all cases, values of OD were only recorded after they had come to a constant value, which was reached within 5 minutes of inserting the dosimeter into the sample chamber of the spectrophotometer. Results: The temperature dependence of the OD at 676 nm was measured in 2 studies using 6 dosimeters that had received 0, 1.0, 3.5, 6.2, 14.5 Gy. Readings were taken at 7 temperatures between 18.8 and 28.1 deg. C. By returning to the initial temperature several hours later, it was found

S-Cam 3: Optical astronomy with a STJ-based imaging spectrophotometer

International Nuclear Information System (INIS)

Verhoeve, P.; Martin, D.D.E.; Hijmering, R.A.; Verveer, J.; Dordrecht, A. van; Sirbi, G.; Oosterbroek, T.; Peacock, A.

2006-01-01

S-Cam 3 is the third generation of a cryogenic camera, based on superconducting tunnel junctions (STJs), for ground-based optical astronomy, deployed at the 4.2 m William Herschel Telescope (WHT) at La Palma (Spain). It exploits a 10x12 pixel array of Ta/Al STJs, covering a field of view of ∼9''x11'' on the sky. The wavelength band extends from 330-750 nm, with a wavelength resolving power of ∼10 at 500 nm. The detectors are operated at ∼285 mK, achieved with a double stage 4 He- 3 He sorption cooler. Each pixel has its own electronic readout chain at room temperature, with a JFET-based charge sensitive preamplifier. The instrument has undergone extensive testing and calibration, followed by the first observation campaign at La Palma in July 2004. This campaign has focused on point sources with time variability, exploiting the instrument's unique combination of spectrophotometry with high time resolution

Optical fiber-spectrophotometer coupling: when will the measurement be on line

International Nuclear Information System (INIS)

Anon.

1984-01-01

Ten years of research and development made at CEA in colorimetry and remote spectrometry by optical fibers allow to define more precisely the best conditions for on-line measurement in industrial process controls and in laboratory analysis in adverse environment. This article presents the new possibilities brought by this type of measurement. One of them is the simultaneous determination of many components; current studies concern the control ''in situ'' of uranium (IV) and (VI) and plutonium (III) and (IV) mixtures [fr

Error analysis of Dobson spectrophotometer measurements of the total ozone content

Science.gov (United States)

Holland, A. C.; Thomas, R. W. L.

1975-01-01

A study of techniques for measuring atmospheric ozone is reported. This study represents the second phase of a program designed to improve techniques for the measurement of atmospheric ozone. This phase of the program studied the sensitivity of Dobson direct sun measurements and the ozone amounts inferred from those measurements to variation in the atmospheric temperature profile. The study used the plane - parallel Monte-Carlo model developed and tested under the initial phase of this program, and a series of standard model atmospheres.

A solid-state dedicated circularly polarized luminescence spectrophotometer: Development and application.

Science.gov (United States)

Harada, Takunori; Hayakawa, Hiroshi; Watanabe, Masayuki; Takamoto, Makoto

2016-07-01

A new solid-state dedicated circularly polarized luminescence (CPL) instrument (CPL-200CD) was successfully developed for measuring true CPL spectra for optically anisotropic samples on the basis of the Stokes-Mueller matrix approach. Electric components newly installed in the CPL-200CD include a pulse motor-driven sample rotation holder and a 100 kHz lock-in amplifier to achieve the linearly polarized luminescence measurement, which is essential for obtaining the true CPL signal for optically anisotropic samples. An acquisition approach devised for solid-state CPL analysis reduces the measurement times for a data set by ca. 98% compared with the time required in our previous method. As a result, the developed approach is very effective for samples susceptible to light-induced degradation. The theory and implementation of the method are described, and examples of its application to a CPL sample with macroscopic anisotropies are provided. An important advantage of the developed instrument is its ability to obtain molecular information for both excited and ground states because circular dichroism measurements can be performed by switching the monochromatic light to white light without rearrangement of the sample.

Teaching UV-Vis Spectroscopy with a 3D-Printable Smartphone Spectrophotometer

Science.gov (United States)

Grasse, Elise K.; Torcasio, Morgan H.; Smith, Adam W.

2016-01-01

Visible absorbance spectroscopy is a widely used tool in chemical, biochemical, and medical laboratories. The theory and methods of absorbance spectroscopy are typically introduced in upper division undergraduate chemistry courses, but could be introduced earlier with the right curriculum and instrumentation. A major challenge in teaching…

Cathodoluminescence study of vickers indentations in magnesium ...

African Journals Online (AJOL)

Vickers diamond pyramid indentations made in single crystal of magnesium oxide (MgO) were examined in an environmental scanning electron microscope interfaced with an AVS-2000 spectrophotometer for luminescence. Three distinct zones around the indentations were identified to exhibit cathodoluminescence, which ...

Evolution of Instrumentation for UV-Visible Spectrophotometry. Part I.

Science.gov (United States)

Altemose, Ines R.

1986-01-01

Traces the development of instruments used in spectrophotometry. Discusses how spectrophotometric measurements are made. Describes the color comparator, the filter photometer, and the spectrophotometer. Outlines the evolution of optical systems, including light sources, the monochromator, the photodetector, double-beam optics, and split-beam…

Development of a Simple System for the Determination of Arsenic ...

African Journals Online (AJOL)

injected such that the excess molecular hydrogen evolved carries the generated arsine directly through the atomic absorption spectrophotometer nebuliser to a nitrogen-hydrogen entrained air flame for atomic absorption measurement is described. The average ... Gas flow rates affected sensitivity markedly, but the

effect of carbide waste on the properties of rice husk ash concrete.

African Journals Online (AJOL)

DJFLEX

KEY WORDS: Carbide Waste, Rice Husk Ash, Cement, Concrete and Rigid Pavement. INTRODUCTION .... and alumina components of the RHA, this ... Chemical analysis of CW, ... Kaduna, using X-ray analyzer together with. Atomic Absorption Spectrophotometer (AAS). ... determine the compressive strength at each level.

Nigella sativa L.

African Journals Online (AJOL)

ajl yemi

2011-10-26

Oct 26, 2011 ... and agro-biodiversity in black cumin (Nigella sativa L.) genotypes from ... analysis. INTRODUCTION. Among the medicinal plants in use from prehistoric times, .... AA240 FS Fast sequential atomic absorption spectrophotometer) ... Lead (Pb) mg kg- ..... for herbal, pharmaceutical, neutraceutical and cosmetic.

Investigation of relationship between sediment characteristics and ...

African Journals Online (AJOL)

ADOWIE PERE

Correlation analysis was used to test association between sediment characteristics and ... could lead to elevated levels of heavy metals in water bodies. Essentially ... cosmetics & traditional medicines and when Lead pipes are being ... Atomic. Absorption. Spectrophotometer (AAS) was calibrated with various standards for ...

Indium oxide thin film based ammonia gas and ethanol vapour sensor

Indian Academy of Sciences (India)

Unknown

acetone and dried under an electric lamp (100 W). Thin films of indium oxide ... A λ-19, UV–VIS Spectrophotometer (Perkin Elmer, USA) was used for measuring .... tion of ammonia is observed through glowing of LED. LM3914, LED driver is ...

Introduction to Instrumental Analysis of Water Pollutants. Training Manual.

Science.gov (United States)

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This course is designed for those requiring an introduction to instruments commonly used in water pollution analyses. Examples are: pH, conductivity, dissolved oxygen meters, spectrophotometers, turbidimeters, carbon analyzer, and gas chromatographs. Students should have a basic knowledge of analytical chemistry. (CO)

Evaluation of essential trace metals in female type 2 diabetes ...

African Journals Online (AJOL)

SAM

2014-04-30

Apr 30, 2014 ... levels of the elements were determined using atomic absorption spectrophotometer (AAS) after acid digestion. ... These included proteinuria, pregnancy, lactating mothers and .... insulin, it also enhance cells uptake of insulin and there- ... transplantation in newly diagnosed type 1 diabetic mellitus JAMA.

Biodegradation of Crude-oil by Fungi Isolated from Cow Dung ...

African Journals Online (AJOL)

http://www.ajol.info/index.php/njb/index ... Chromatography and Mass Spectrophotometer (GC-MS). The GC-MS analysis ... In this study, attention is paid to source for fungi from ..... utilization of a PAH as a selective medium for the growth of ...

The evaluation of a novel method comparing quantitative light-induced fluorescence (QLF) with spectrophotometry to assess staining and bleaching of teeth

NARCIS (Netherlands)

Adeyemi, A.A.; Jarad, F.D.; de Josselin de Jong, E.; Pender, N.; Higham, S.M.

2010-01-01

This study reports the development and evaluation of a novel method using quantitative light-induced fluorescence (QLF), which enables its use for quantifying and assessing whole tooth surface staining and tooth whitening. The method was compared with a spectrophotometer to assess reliability. Two

STECH,4(1), S/NO 9, FEBRUARY, 2015

African Journals Online (AJOL)

ZTE

2015-02-09

Feb 9, 2015 ... spectrophotometer. From the spectral analysis of absorbance and transmittance, the optical and solid properties were obtained. The properties studied include the reflectance, absorption coefficient, thickness, refractive index, extinction coefficient, optical conductivity and band gap energy. The films show ...

Quality of Packaged Waters Sold in Ibadan, Nigeria

African Journals Online (AJOL)

Samuel Olaleye

spectrophotometer and analytical quality chemical reagents were used for chemical analyses. MacConkey broth .... 25cl or 30cl nylon / plastic film sachets and sealed by heat at ... topped with a piece of cloth, nylon wrap or rags to strain off any ...

PRELIMINARY STUDY ON THE KINETIC PROFILE OF SULFAMETHAZINE IN ADULT LOCAL BREED DOG KAJIAN AWAL TENTANG PROFIL KINETIK SULFAMETAZIN PADA PERANAKAN ANJING LOKAL DEWASA

Directory of Open Access Journals (Sweden)

Mochamad Lazuardi

2007-06-01

Full Text Available The kinetic parameters of sulmethazine in blood plasma were investigated by UV-Vis spectrophotometer at vaious times following intramuscular administration of 50 mg/kg body weight in local breed dog (Surabaya breed x DEnpasar breed. The objectives of this research

Effects of the Consortium of Pseudomonas, Bacillus and ...

African Journals Online (AJOL)

The effect of the consortium of Pseudomonas, Bacillus and Micrococcus spp on polycyclic aromatic hydrocarbons in crude oil was carried out using standard microbiological methods. Spectrophotometer, gas chromatography and viable count which determined the optical density, the polycyclic aromatic hydrocarbons and ...

Equipment gift to Monaco

International Nuclear Information System (INIS)

1970-01-01

Research work at the Agency's Laboratory of Marine Radioactivity in Monaco, including that concerned with pollution of the sea, has been made more effective by its latest acquisition of equipment. This is a spectrophotometer donated by the Federal Republic of Germany. (author)

Download this PDF file

African Journals Online (AJOL)

10865

2013-10-30

Oct 30, 2013 ... DOI: 10.5897/AJB12.2940. ISSN 1684-5315 ©2013 Academic Journals .... were covered with a light fine-porous cloth (curtain fabric), mimicking a ... 1000 spectrophotometer (software ND-1000 V3.5.1; USA). The. DNA purity ...

Metal (Co, Fe) tribenzotetraazachlorin-fullerene conjugates: impact of direct p-bonding on the redox behaviour and oxygen reduction reaction

CSIR Research Space (South Africa)

Ozoemena, KI

2009-06-01

Full Text Available 123UV–vis spectra measurements were recorded using a Cary 300 124UV–vis spectrophotometer, driven by Varian software version 1253.0. All electrochemical studies were performed with Autolab 126PGSTAT 20, GPES 4.9 software (Eco-Chemie, Utrecht...

Standard Test Methods for Solar Energy Transmittance and Reflectance (Terrestrial) of Sheet Materials

CERN Document Server

American Society for Testing and Materials. Philadelphia

1971-01-01

1.1 These test methods cover the measurement of solar energy transmittance and reflectance (terrestrial) of materials in sheet form. Method A, using a spectrophotometer, is applicable for both transmittance and reflectance and is the referee method. Method B is applicable only for measurement of transmittance using a pyranometer in an enclosure and the sun as the energy source. Specimens for Method A are limited in size by the geometry of the spectrophotometer while Method B requires a specimen 0.61 m2 (2 ft2). For the materials studied by the drafting task group, both test methods give essentially equivalent results. 1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Applicability of a prototype for determination of absorbed dose using brachytherapy equipment with Ir-192 sources; Aplicabilidade de um prototipo para determinacao da dose absorvida utilizando equipamentos de braquiterapia com fontes de IR-192

Energy Technology Data Exchange (ETDEWEB)

Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila, E-mail: vlsouza@cnen.gov.br, E-mail: mayaradqf@hotmail.com, E-mail: rodriguesss@hootmail.com, E-mail: waldecy@cnen.gov.br, E-mail: riziakeila@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

2014-07-01

This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose.

Applicability of a prototype for determination of absorbed dose using brachytherapy equipment with Ir-192 sources

International Nuclear Information System (INIS)

Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila

2014-01-01

This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose

Validation of the FACSCount AF system for determination of sperm concentration in boar semen

DEFF Research Database (Denmark)

Hansen, C.; Christensen, P.; Stryhn, H.

2002-01-01

microspheres ( beads). Satisfactory staining can be achieved within 2-3 min and the following flow cytometric analysis on the FACSCount AF System rapidly provides the user with a precise and accurate assessment of the sperm concentration. In this study, the FACSCount AF System and Sperm Counting Reagent ( BD...... Biosciences) was compared with microscopic counting using a Burker-Turk haemocytometer. In addition, sperm concentration was determined using the Corning 254 spectrophotometer which is used routinely by Danish artificial insemination stations for boars. The results show that the agreement between flow...... cytometry and microscopic counting is very high. The slope for the regression line was 1.12 (SE = 0.03) with an estimated intercept with the Y-axis of 22 x 10(6) sperm/ml (SE = 10 x 10(6) sperm/ml) and an estimated error of the model of 10 x 10(6) sperm/ml. For the spectrophotometer, the slope...

Microstructure and optical properties of nanocrystalline Cu2O thin films prepared by electrodeposition.

Science.gov (United States)

Jiang, Xishun; Zhang, Miao; Shi, Shiwei; He, Gang; Song, Xueping; Sun, Zhaoqi

2014-01-01

Cuprous oxide (Cu2O) thin films were prepared by using electrodeposition technique at different applied potentials (-0.1, -0.3, -0.5, -0.7, and -0.9 V) and were annealed in vacuum at a temperature of 100°C for 1 h. Microstructure and optical properties of these films have been investigated by X-ray diffractometer (XRD), field-emission scanning electron microscope (SEM), UV-visible (vis) spectrophotometer, and fluorescence spectrophotometer. The morphology of these films varies obviously at different applied potentials. Analyses from these characterizations have confirmed that these films are composed of regular, well-faceted, polyhedral crystallites. UV-vis absorption spectra measurements have shown apparent shift in optical band gap from 1.69 to 2.03 eV as the applied potential becomes more cathodic. The emission of FL spectra at 603 nm may be assigned as the near band-edge emission.

Laser induced fluorescence technique for detecting organic matter in East China Sea

Science.gov (United States)

Chen, Peng; Wang, Tianyu; Pan, Delu; Huang, Haiqing

2017-10-01

A laser induced fluorescence (LIF) technique for fast diagnosing chromophoric dissolved organic matter (CDOM) in water is discussed. We have developed a new field-portable laser fluorometer for rapid fluorescence measurements. In addtion, the fluorescence spectral characteristics of fluorescent constituents (e.g., CDOM, chlorophyll-a) were analyzed with a spectral deconvolution method of bi-Gaussian peak function. In situ measurements by the LIF technique compared well with values measured by conventional spectrophotometer method in laboratory. A significant correlation (R2 = 0.93) was observed between fluorescence by the technique and absorption by laboratory spectrophotometer. Influence of temperature variation on LIF measurement was investigated in lab and a temperature coefficient was deduced for fluorescence correction. Distributions of CDOM fluorescence measured using this technique in the East China Sea coast were presented. The in situ result demonstrated the utility of the LIF technique for rapid detecting dissolved organic matter.

Reflection measurements for luminescent powders

Science.gov (United States)

Kroon, R. E.

2018-04-01

Luminescent materials are useful in applications varying from lighting and display technologies to document security features and medical research, amongst many others. Measurement of the excitation range is an important consideration, and absorption bands are often determined from a decrease in the measured diffuse reflectance of the material using a ultraviolet-visible (UV-vis) spectrophotometer with an integrating sphere. Such a system may provide questionable results when used to measure the reflectance of a luminescence material, which is demonstrated for a Tb doped silica phosphor, because the system cannot differentiate between the reflected light and luminescence. It is shown that more reliable results are achieved for this phosphor by measuring the reflectance using a synchronous zero-offset scan in a fluorescence spectrometer equipped with an integrating sphere. This method is therefore recommended instead of traditional reflectance measurements using a UV-vis spectrophotometer for luminescent powders.

Development of mixed-waste analysis capability for graphite furnace atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Bass, D.A.; TenKate, L.B.; Wroblewski, A.

1995-03-01

Graphite furnace atomic absorption spectrophotometer (GFAAS) are typically configured with ventilation to capture potentially toxic and corrosive gases emitted from the vaporization of sample aliquots. When radioactive elements are present, additional concerns (such as meeting safety guidelines and ALARA principles) must be addressed. This report describes a modification to a GFAAS that provides additional containment of vaporized sample aliquots. The modification was found to increase containment by a factor of 80, given expected operating conditions. The use of the modification allows more mixed-waste samples to be analyzed, permits higher levels of radioactive samples to be analyzed, or exposes the analyst to less airborne radioactivity. The containment apparatus was attached to a Perkin-Elmer Zeeman 5000 spectrophotometer for analysis of mixed-waste samples; however, it could also be used on other systems and in other applications where greater containment of vaporized material is desired

Comparative analysis of colour change measurement devices in textile industry

Directory of Open Access Journals (Sweden)

Paulina Gilewicz

2014-08-01

Full Text Available In the paper there is presented a trial of application of new measurement principle of colour change with the use of DigiEye device. Comparison of DigiEye with commonly use in the textile industry spectrophotometer Macbeth 2020 was an aim of determination of relationship between parameters of both measurement systems. Samples for the colour change assessment on both measurement systems were first aged in the Xenotest 150. Ageing process was done according to the method of blues scale. Results were obtained by the colour measurement devices before and after the ageing test each releasing the diaphragms during exposing the examined samples on the light. Result of colour change were obtained in the colour system CIE L*a*b*. The measurements were done for PES fabrics destined on the outer layers of clothing. [b]Keywords[/b]: textiles, spectrophotometer, colorimeter [b][/b

Determining CDOM Absorption Spectra in Diverse Coastal Environments Using a Multiple Pathlength, Liquid Core Waveguide System. Measuring the Absorption of CDOM in the Field Using a Multiple Pathlength Liquid Waveguide System

Science.gov (United States)

Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

2000-01-01

We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, a(sub CDOM), and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values (r > 0.99) and showed a linear response across all four pathlengths. Values of a(sub CDOM) measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of a(sub CDOM) for MPLCW measurements was 0.002 - 231.5/m. At low CDOM concentrations (a(sub 370) CDOM) were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples. The maximum deviation in replicate MPLCW spectra was less than 0.001 absorbance units. The portability, sampling, and optical characteristics of a MPLCW system provide significant enhancements for routine CDOM absorption measurements in a broad range of natural waters.

Outlier detection in UV/Vis spectrophotometric data

NARCIS (Netherlands)

Lepot, M.J.; Aubin, Jean Baptiste; Clemens, F.H.L.R.; Mašić, Alma

2017-01-01

UV/Vis spectrophotometers have been used to monitor water quality since the early 2000s. Calibration of these devices requires sampling campaigns to elaborate relations between recorded spectra and measured concentrations. In order to build robust calibration data sets, several spectra must be

Antibacterial properties and preliminary phytochemical analysis of ...

African Journals Online (AJOL)

Partial purification (Thin Layer Chromatography) of the crude extract revealed five (5) components. Characteristics of these components were viewed by Infrared and UV/VIS spectrophotometer showing the presence of alkaloid, saponin, tannin, steroid and flavonoid. The observed antibacterial activity was believed to be due ...

Preliminary investigation into the chemical composition of the ...

African Journals Online (AJOL)

Nutritional and toxicological analyses were carried out using an Atomic Absorption Spectrophotometer (AAS) 900T. Results of the study indicated that the Sargassum samples analyzed contained low concentrations of nitrogen. However, nitrogen utilized by plants, namely, nitrate and ammonia were very high, together with ...

Levels of Some Selected (Essential-Mn, Zn and Toxic-Al, Sb) Metals in

African Journals Online (AJOL)

The fish were dissected, blood samples were obtained and the tissues were digested with standard methodsand assayed for levels of manganese, zinc, aluminum and antimony using inductively coupled plasma mass spectrophotometer (ICP-MS). Results obtained showed that the mean concentration of the elements ...

Evaluation of Extraction Methods for the Analysis of Carotenoids for Different Vegetable Matrix

Directory of Open Access Journals (Sweden)

Stancuta Scrob

2013-11-01

Full Text Available In this study, different solvents were used to achieve the maximum extractibility of total carotenoids. The extracted total carotenoids were estimated using UV- visible spectrophotometer. Carotenoids from vegetable matrix can be used as a food colorant, food additive, cosmetics, antioxidants and nutraceuticals.

Comparative study of cocoa-sweat and that of pure honey

African Journals Online (AJOL)

USER

2010-05-17

May 17, 2010 ... initiative and enterprise of Nigeria peasant farmers. The ... Babatunde, 2006), for Clarias catfish feeds (Hamzat et al., 2006), for cocoa .... Inaugural Lecture. Series 36, Federal University of Technology, Akure, Nigeria. Dubois S (1956). Spectrophotometer Method for Determination of Sugar and Related ...

The pH dependent toxicity and bioaccumulation of chloroquine tested on S. viminalis (basket willow)

DEFF Research Database (Denmark)

Rendal, Cecilie; Trapp, Stefan; Legind, Charlotte Nielsen

2010-01-01

(hydroxymethyl) – aminomethane (pH 8 and 9). Concentrations were determined with spectrophotometer. Toxicity was derived from calculations of normalized transpiration over time, and RCF (root concentration factor) values were calculated. Increasing BCF values were found for increasing pH levels, and the toxicity...

Synthesis of 1-D ZnO nanorods and polypyrrole/1-D ZnO ...

Indian Academy of Sciences (India)

1-D ZnO nanorods and PPy/1-D ZnO nanocomposites were prepared by the surfactant-assisted precipitation and in situ polymerization method, respectively. The synthesized nanorods and nanocomposites were characterized by UV–Vis spectrophotometer, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction ...

Sequential Analysis of Metals in Municipal Dumpsite Composts of ...

African Journals Online (AJOL)

... Ni) in Municipal dumpsite compost were determined by the sequential extraction method. Chemical parameters such as pH, conductivity, and organic carbon contents of the samples were also determined. Analysis of the extracts was carried out by atomic absorption spectrophotometer machine (Buck Scientific VPG 210).

Oyebola et al (23).cdr

African Journals Online (AJOL)

Timothy Ademakinwa

3+ described elsewhere (Oyebola et al., 2010). Ho absorption peaks were obtained from transmission studies carried out with a Cary 5000. UV-VIS-NIR spectrophotometer and corresponding absorption coefficients deduced using the Beer-Lambert law. Spectral emission measurements were carried out using the schematic ...

concentration levels of major and trace metals in onion

African Journals Online (AJOL)

Preferred Customer

like stews, soups, tomato sauces, cooked vegetables and meat by slicing, chopping, ... including metal concentrations in soils, soil pH, cation exchange capacity, ... determination was done by flame atomic absorption spectrophotometer (FAAS) (Buck ...... Margen, S. Onions, The Wellness Encyclopedia of Food and Nutrition, ...

INVESTIGATION ON PLEUROTUS FERULAE POTENTIAL FOR ...

African Journals Online (AJOL)

Preferred Customer

7.5), temperature (30-50 oC), biomass dosage of 0.5-4 g and initial metal ... spectrophotometer (AAS Alpha 4 model, USA) was used for analysis of the metal ions and ... is present at 1541 cm−1 assigned to –NH deformation conjugated to.

Monitoring of endocrine disrupting chemicals in surface water

CSIR Research Space (South Africa)

Govender, S

2008-06-01

Full Text Available monitored at 25°C in a CARY 110 UV-Vis spectrophotometer. A Beckman spectrophotometric plate reader was used to measure the activity of avidin conjugated peroxidase (Av-P). In the presence of sufficient affinity immobilized Av-P, the ABTS solution...

assessment of heavy metals concentration in drinking water ...

African Journals Online (AJOL)

userpc

guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit of WHO. Keywords: Atomic Absorption Spectrophotometers, Heavy Metals, Water, Kauru Local. Government Area.

African Journal of Science and Technology (AJST) IMPACT OF ...

African Journals Online (AJOL)

This paper discusses the impact of these activities on heavy metal loading in different media within the wetlands. ... cosmetics industry (Hg). .... All the analysis of heavy metals was done at the Southern ... using a Flame Atomic Absorption Spectrophotometer (AAS). ..... battery manufacture and dilapidated lead sewage pipes.

SHORT COMMUNICATION IMPACT OF ENVIRONMENTAL ...

African Journals Online (AJOL)

Preferred Customer

This study evaluated the levels of cadmium, lead, copper and zinc in the ... analysis showed significant correlation (p < 0.01) between the metal levels in .... Atomic Absorption Spectrophotometer (UNICAM, UK) using air-acetylene flame. .... exceeded the 20 mg/kg recommended by Food Stuff, Cosmetics and Disinfectant Act.

Chemical and nutritional values of maize and maize products ...

African Journals Online (AJOL)

Maize and maize products in selected grain markets within Kaduna, Nigeria, were obtained and investigated for proximate and mineral composition analysis using Atomic Absorption Spectrophotometer (AAS) and flame photometer. Proximate composition of maize and maize products were in the range of 11.6- 20 .0% ...

Lead Content of Well Water in Enugu South-East Nigeria | Ogbu ...

African Journals Online (AJOL)

Aim: To study the lead content of well water in Enugu, Southeast Nigeria. Method: Wells (101) were located using the multistage sampling procedure and samples were collected into clean plastic containers. Analysis was done using atomic absorption spectrophotometer. Result: The means lead content of well water ...

Method 446.0: In Vitro Determination of Chlorophylls a, b, c + c and Pheopigments in 1 2Marine And Freshwater Algae by Visible Spectrophotometry

Science.gov (United States)

This method provides a procedure for determination of chlorophylls a (chl a), b (chl b), c + c 1 2 (chl c + c ) and pheopigments of chlorophyll a (pheo a) 1 2 found in marine and freshwater phytoplankton. Chlorophyllide a is determined as chl a. Visible wavelength spectrophotomet...

In situ determination of the reduction levels of cytochromes b and c in growing bacteria : a case study with N2-fixing Azorhizobium caulinodans

NARCIS (Netherlands)

Pronk, A.F.; Boogerd, F C; Stoof, C.; Oltmann, L F; Stouthamer, A.H.; van Verseveld, H W

1993-01-01

The determination of the in situ reduction levels of cytochromes b and c in growing bacteria is achieved by coupling a chemostat with a dual wavelength spectrophotometer. Visible light absorption spectra of cytochromes present in bacterial cells actively growing in a chemostat at a specific growth

Performance of a solar collector with antireflection treated glass cover

DEFF Research Database (Denmark)

Duer, Karsten

1999-01-01

The spectral transmittances of two different glass types have been measured in a spectrophotometer. Both glass types have been investigated with and without a Sunarc anti reflection surface (AR surface). The transmittance data for the AR treated samples have been used as input to the AR treatment...

Estimation of Heavy Metals in Neem Tree Leaves along Katsina ...

African Journals Online (AJOL)

Widespread and growing use of medicinal plants has created public health challenges in terms of quality, safety and effectiveness. Using Atomic Absorption Spectrophotometer (AAS), concentrations of Ni, Zn, Mn, Cu, Cr and Pb, , were determined in samples of neem tree (Azadirachta indica) leaves obtained from Katsina, ...

Behavior of manganese ion in basic medium: consequence for the ...

African Journals Online (AJOL)

Dr. J. T. Ekanem

2006-01-25

Jan 25, 2006 ... adding manganese chloride or manganese sulfate to sodium hydroxyde or sodium carbonate in aqueous ... carbonate (1 M). The release of p- nitrophenoxide anion (pNP) was quantified at. 420 nm using a spectrophotometer (Spectronic. Genesis 5). .... These curves were bell-type with an ascending.

Untitled

African Journals Online (AJOL)

M Tris-acetate or phosphate buffer. Monitoring the decreasing NADH concentration after the enzymatic reaction produced peaks which formed the basis for measuring ammonia. Detection was made with a flow-through spectrophotometer (at 340 nm) or amperometric detector with a wall-jet phenoxazine-modified graphite ...

The Determination of Anionic Surfactants in Natural and Waste Waters.

Science.gov (United States)

Crisp, P. T.; And Others

1983-01-01

Background information, procedures, and results of an experiment suitable for measuring subpart per million concentrations of anionic surfactants in natural waters and waste effluents are provided. The experiment required only a spectrophotometer or filter photometer and has been successfully performed by students in an undergraduate environmental…

Comparative analysis of different brands of prednisolone tablets ...

African Journals Online (AJOL)

The experiment involves analysis of nine brands of prednisolone, using ultra violet spectrophotometer in the range of (200-400nm) and high performance liquid chromatography (HPLC) in which the samples were dissolved in various solvents and their various absorbance, peak area at various wavelength were determined ...

Attanayake et al., Afr J Tradit Complement Altern Med. (2015) 12(4 ...

African Journals Online (AJOL)

Proff.Adewunmi

Materials and Methods: DPPH(2, 2-diphenyl-2-picrylhydrazyl), FRAP (ferric reducing power) and ... A Sanyo Gallenkamp (model SP65) spectrophotometer was ... mixed with 1.0 mL of 95% ethanol, 5.0 mL of distilled water and 0.5 mL of 50% ...

Mineral Elements Content of some Coarse Grains used as staple ...

African Journals Online (AJOL)

Analysis of mineral elements were carried out on some coarse grains used as staple food in Kano metropolis. The levels of Magnesium, Calcium, Manganese, Iron, Copper and Zinc were determined using atomic absorption spectrophotometer (AAS), and that of Sodium and Potassium were obtained using flame photometer ...

The Use of a Microprocessor-Controlled, Video Output Atomic Absorption Spectrometer as an Educational Tool in a Two-Year Technical Curriculum.

Science.gov (United States)

Kerfoot, Henry B.

Based on instructional experiences at Charles County Community College, Maryland, this report examines the pedagogical advantage of teaching atomic absorption (AA) spectroscopy with an AA spectrophotometer that is equipped with a microprocessor and video output mechanism. The report first discusses the growing importance of AA spectroscopy in…

Assessment of heavy metals, pH and EC in effluent run-off, river and ...

African Journals Online (AJOL)

Heavy metal contents from effluent run-off, neighboring Holeta River, and adjacent soils around floriculture greenhouses in Holeta town, Ethiopia were determined using Atomic Absorption Spectrophotometer (AAS) to assess their potentialities as pollutants. Samples were taken from four sites for the effluent, two river bank ...

Design philosophy and construction of a high concentration compound parabolic concentrator

CSIR Research Space (South Africa)

Roos, TH

2010-09-01

Full Text Available mm samples were measured in a Cary spectrophotometer. The mean transmission of these samples is shown in comparison to a regular 2mm soda-lime glass sample (non-mirror application) from PFG in figure 2 (left). 400 600 800 1000 1200 1400 1600 1800...

Determination of free radical scavenging activity from aqueous extract of Curcuma mangga by DPPH method

Science.gov (United States)

Indis, N. A.; Kurniawan, F.

2016-04-01

Curcuma mangga (mango ginger) belongs to the family of Zingiberaceae. The rhizome of C. mangga are morphologically similar to ginger (Zingiber officinale) with a little mango flavour. C. mangga can growth in tropical areas and easy found in Indonesia. The rhizomes of C. mangga were washed and cut into the small piece, then drying at room temperature for 6 days, and then grinded until get the powder of C. mangga. The powder of C. mangga was extracted with deminerahzed water by maceration for 6 hours. C. mangga extract was analysed with FTIR spectrophotometer to determine its functional groups. C. mangga extract was diluted at various of concentration (5, 10, 25, 50, 100, 250, 500 mg/L) using deminerahzed water. C. mangga extracts were tested the antioxidant activity using 0.002% DPPH at 517nm with UV-Vis spectrophotometer, and the IC50 value of C. mangga extract is 212.70 mg/L.

Estimation of Anthocyanin Content of Berries by NIR Method

International Nuclear Information System (INIS)

Zsivanovits, G.; Ludneva, D.; Iliev, A.

2010-01-01

Anthocyanin contents of fruits were estimated by VIS spectrophotometer and compared with spectra measured by NIR spectrophotometer (600-1100 nm step 10 nm). The aim was to find a relationship between NIR method and traditional spectrophotometric method. The testing protocol, using NIR, is easier, faster and non-destructive. NIR spectra were prepared in pairs, reflectance and transmittance. A modular spectrocomputer, realized on the basis of a monochromator and peripherals Bentham Instruments Ltd (GB) and a photometric camera created at Canning Research Institute, were used. An important feature of this camera is the possibility offered for a simultaneous measurement of both transmittance and reflectance with geometry patterns T0/180 and R0/45. The collected spectra were analyzed by CAMO Unscrambler 9.1 software, with PCA, PLS, PCR methods. Based on the analyzed spectra quality and quantity sensitive calibrations were prepared. The results showed that the NIR method allows measuring of the total anthocyanin content in fresh berry fruits or processed products without destroying them.

In-vitro Anticancer and Antioxidant Activity of Gold Nanoparticles Conjugate with Tabernaemontana divaricata flower SMs Against MCF -7 Breast Cancer Cells

International Nuclear Information System (INIS)

Preetam, Raj J. P.; Purushothaman, M; Khusro, Ameer; Panicker, Shirly George

2016-01-01

Biologically stabilized gold nanoparticles were synthesized from the flower aqueous extract of T. divaricata. The synthesized nanoparticles were characterized by UV-Vis spectrophotometer, Zeta sizer, FTIR and TEM analysis. T. divaricata reduced gold nanoparticles having particle size and potential of 106.532 nm and -10.2 mV, respectively, with a characteristic peak of 550 nm in UV-visible spectrophotometer. FTIR graph after comparison between the crude flower extract and gold nanoparticles showed three major shifts in the functional groups. The morphology and size of the gold nanoparticles were examined by HRTEM analysis, which showed that most of the nanoparticles were nearly spherical with size of 100 nm. The gold nanoparticles synthesized demonstrated potent anticancer activity against MCF-7 cell line. The findings conclude that the antioxidant molecule present in T. divaricata may be responsible for both reduction and capping of gold nanoparticles which possess potential applications in medicine and pharmaceutical fields

Determination of free radical scavenging activity from aqueous extract of Curcuma mangga by DPPH method

International Nuclear Information System (INIS)

Indis, N A; Kurniawan, F

2016-01-01

Curcuma mangga (mango ginger) belongs to the family of Zingiberaceae. The rhizome of C. mangga are morphologically similar to ginger (Zingiber officinale) with a little mango flavour. C. mangga can growth in tropical areas and easy found in Indonesia. The rhizomes of C. mangga were washed and cut into the small piece, then drying at room temperature for 6 days, and then grinded until get the powder of C. mangga. The powder of C. mangga was extracted with deminerahzed water by maceration for 6 hours. C. mangga extract was analysed with FTIR spectrophotometer to determine its functional groups. C. mangga extract was diluted at various of concentration (5, 10, 25, 50, 100, 250, 500 mg/L) using deminerahzed water. C. mangga extracts were tested the antioxidant activity using 0.002% DPPH at 517nm with UV-Vis spectrophotometer, and the IC 50 value of C. mangga extract is 212.70 mg/L. (paper)

Neutron Fluence Evaluation using an Am-Be Neutron Sources Assembly and P ADC Detectors

International Nuclear Information System (INIS)

Seddik, U.

2008-01-01

An assembly of four 241 Am-Be sources has been constructed at Nuclear Reactions Unit (NRU) of Nuclear Research Center (NRU) to perform analysis of different materials using thermal and fast neutrons. In the present paper, we measure the value of transmittance (T) in percentage of etched CR-39 detectors using a spectrophotometer at different neutron fluences ,to relate the transmittance of the detector with the neutron fluence values. The exposed samples to neutrons with accumulated fluence of order between 10 10 and 10 12 cm -2 were etched for 15 time intervals between 10-600 min in 6.25 N NaOH at 70 degree C. The etched samples were analyzed using Tech 8500 II spectrophotometer. A trend of the sample transmission and the etching time is observed which is different for each fluence value. A linear relation between the transmittance decay constant and the neutron fluence is observed which could be used as a calibration to determine unknown neutron fluence

A novel high performance stopped-flow apparatus equipped with a special constructed mixing chamber containing a plunger under inert condition with a very short dead-time to investigate very rapid reactions

Directory of Open Access Journals (Sweden)

Sayyed Mostafa Habibi Khorassani

2015-11-01

Full Text Available The present work set out to establish a novel stopped-flow instrument equipped with a special constructed mixing chamber containing a plunger to enable a kinetic study of the very rapid reactions under a dry inert atmosphere glove bag, in particular, for the reactions are sensitive to moisture or air. A stopped-flow spectrophotometer is essentially a conventional spectrophotometer with the addition of a system for rapid mixing of solutions. The purpose of this work is to describe the fabrication and evaluation of specially constructed and in-expensive stopped-flow system. The evaluation includes determination of the dead-time, relative mixing efficiency, and the measurement of known rate constants. Herein, a dead-time of about 3.4 ms was determined in the final modified construction of the stopped-flow apparatus in order to investigate the rapid initial during which some form of reaction intermediate is presented to be formed.

In-vitro Anticancer and Antioxidant Activity of Gold Nanoparticles Conjugate with Tabernaemontana divaricata flower SMs Against MCF -7 Breast Cancer Cells

Energy Technology Data Exchange (ETDEWEB)

Preetam, Raj J. P.; Purushothaman, M; Khusro, Ameer; Panicker, Shirly George [PG Biotechnology, Tamil Nadu (India)

2016-02-15

Biologically stabilized gold nanoparticles were synthesized from the flower aqueous extract of T. divaricata. The synthesized nanoparticles were characterized by UV-Vis spectrophotometer, Zeta sizer, FTIR and TEM analysis. T. divaricata reduced gold nanoparticles having particle size and potential of 106.532 nm and -10.2 mV, respectively, with a characteristic peak of 550 nm in UV-visible spectrophotometer. FTIR graph after comparison between the crude flower extract and gold nanoparticles showed three major shifts in the functional groups. The morphology and size of the gold nanoparticles were examined by HRTEM analysis, which showed that most of the nanoparticles were nearly spherical with size of 100 nm. The gold nanoparticles synthesized demonstrated potent anticancer activity against MCF-7 cell line. The findings conclude that the antioxidant molecule present in T. divaricata may be responsible for both reduction and capping of gold nanoparticles which possess potential applications in medicine and pharmaceutical fields.

Electrical properties of undoped zinc oxide nanostructures at different annealing temperature

Energy Technology Data Exchange (ETDEWEB)

Nasir, M. F., E-mail: babaibaik2002@yahoo.com; Zainol, M. N., E-mail: nizarzainol@yahoo.com; Hannas, M., E-mail: mhannas@gmail.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, Mohamad, E-mail: rusop@salam.uitm.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Rahman, S. A., E-mail: saadah@um.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Low Dimensional Materials Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2016-07-06

This project has been focused on the electrical and optical properties respectively on the effect of Undoped zinc oxide (ZnO) thin films at different annealing temperature which is varied 400 °C, 450 °C, 500 °C, and 550 °C.Undoped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 500 °C which its resistivity is 5.36 × 10{sup 4} Ωcm{sup −1}. The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

Chemical Stability of Cd(II and Cu(II Ionic Imprinted Amino-Silica Hybrid Material in Solution Media

Directory of Open Access Journals (Sweden)

Buhani, Narsito, Nuryono, Eko Sri Kunarti

2015-12-01

Full Text Available Chemical stability of Cd(II and Cu(II ionic imprinted hybrid material of (i-Cd-HAS and i-Cu-HAS derived from silica modification with active compound (3-aminopropyl-trimethoxysilane (3-APTMS has been studied in solution media. Stability test was performed with HNO3 0.1 M (pH 1.35 to investigate material stability at low pH condition, CH3COONa 0.1 M (pH 5.22 for adsorption process optimum pH condition, and in the water (pH 9.34 for base condition. Material characteristics were carried out with infrared spectrophotometer (IR and atomic absorption spectrophotometer (AAS. At interaction time of 4 days in acid and neutral condition, i-Cd-HAS is more stable than i-Cu-HAS with % Si left in material 95.89 % (acid media, 43.82 % (close to neutral, and 9.39 % (base media.Keywords: chemical stability, amino-silica hybrid, ionic imprinting technique

Chemical Stability of Cd(II and Cu(II Ionic Imprinted Amino-Silica Hybrid Material in Solution Media

Directory of Open Access Journals (Sweden)

Buhani Buhani

2012-02-01

Full Text Available Chemical stability of Cd(II and Cu(II ionic imprinted amino-silica (HAS material of (i-Cd-HAS and i-Cu-HAS derived from silica modification with active compound (3-aminopropyl-trimethoxysilane (3-APTMS has been studied in solution media.  Stability test was performed with HNO3 0.1 M (pH 1.35 to investigate material stability at low pH condition, acetat buffer at pH 5.22 for adsorption process optimum pH condition, and in the water (pH 9.34 for base condition.  Material characteristics were carried out with infrared spectrophotometer (IR and atomic absorption spectrophotometer (AAS.  At interaction time of 4 days in acid and neutral condition, i-Cd-HAS is more stable than i-Cu-HAS with % Si left in material 95.89 % (acid media, 43.82 % (close to neutral, and 9.39 % (base media.Keywords: chemical stability, amino-silica hybrid, ionic imprinting technique.

Probing Photocatalytic Characteristics of Sb-Doped TiO2 under Visible Light Irradiation

Directory of Open Access Journals (Sweden)

Lingjing Luo

2014-01-01

Full Text Available Sb-doped TiO2 nanoparticle with varied dopant concentrations was synthesized using titanium tetrachloride (TiCl4 and antimony chloride (SbCl3 as the precursors. The properties of Sb-doped TiO2 nanoparticles were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, fluorescence spectrophotometer, and Uv-vis spectrophotometer. The absorption edge of TiO2 nanoparticles could be extended to visible region after doping with antimony, in contrast to the UV absorption of pure TiO2. The results showed that the photocatalytic activity of Sb-doped TiO2 nanoparticles was much more active than pure TiO2. The 0.1% Sb-doped TiO2 nanoparticles demonstrated the best photocatalytic activity which was better than that of the Degussa P25 under visible light irradiation using terephthalic acid as fluorescent probe. The effects of Sb dopant on the photocatalytic activity and the involved mechanism were extensively investigated in this work as well.

JCSC_129_04_0415_0420_SI.doc

Indian Academy of Sciences (India)

Melting points of all the compounds were recorded by Analab ThermoCal melting point apparatus in the open capillary tube and are uncorrected. The FTIR spectra (KBr) were recorded on Shimadzu FTIRAffinity-1 Fourier Transform Infrared spectrophotometer. 1H NMR spectra were recorded on MR400 Agilent Technology ...

Determination of heavy metals in soils from dump site of tanneries ...

African Journals Online (AJOL)

Heavy metals were determined in soil samples at the dump site, Challawa town, Karfi Irrigation site and farmlands near the dump site by flame Atomic Absorption Spectrophotometer (AAS). The results showed that soil at the dump site contains significant amount of toxic elements. Hence remediation processes were ...

Formulation and Evaluation of Microspheres Based on Gelatin ...

African Journals Online (AJOL)

Patrick Erah

drug delivery systems to achieve a controlled release and site-specific targeting of the incorporated drug. ... a potential alternative to the parenteral route for ... The solution was then filtered and analyzed spectrophotometrically at a wavelength of 280 nm using a UV-Vis spectrophotometer (Spectronic 21D). The drug.

Analysis of some selected toxic metals in registered herbal products ...

African Journals Online (AJOL)

Twenty brands of herbal remedies were purchased randomly from the Pharmacy shops in Lagos, digested with aquaregia (3:1 HCl: HNO3) and were analysed using atomic absorption spectroscopy (Buck 205 Atomic Absorption Spectrophotometer). There was no detectable lead in any of the 20 herbal samples; however, ...

The bio accumulation of some heavy metals in some organs of two ...

African Journals Online (AJOL)

Hence, the bioaccumulation of Zinc (Zn), Iron (Fe), Lead (Pb) and Cadmium (Cd) in samples of gill, Liver and offal of Clarias Gariepinus nigrodigilatus and Chrysichthys from 'Ose' fish landing site of River Niger, at Onitsha was investigated using Atomic Absorption Spectrophotometer (AAS). The result obtained showed that ...

Effect of acute and delayed hyperbaric oxygen therapy on cyanide whole blood levels during acute cyanide intoxication

DEFF Research Database (Denmark)

Lawson-Smith, P; Jansen, E C; Hilsted, Linda Maria

2011-01-01

and the subsequent formation of cyanocobalamin measured by a spectrophotometer. Results showed that whole-blood-cyanide concentration in Group 1 controls and acute HBO2 initially rose and then fell towards zero. In rats treated with delayed HBO2, the reduction in whole-blood-cyanide concentration was significantly...

Specific interaction of central nervous system myelin basic protein with lipids effects of basic protein on glucose leakage from liposomes

NARCIS (Netherlands)

Gould, R.M.; London, Y.

1972-01-01

The leakage from liposomes preloaded with glucose was continuously monitored in a Perkin-Elmer Model 356 dual beam spectrophotometer using an enzyme-linked assay system. The central nervous system myelin basic protein (A1 protein) caused a 3–4-fold increase in the rate of leakage from liposomes

Metrological traceability of holmium oxide solution

Science.gov (United States)

Gonçalves, D. E. F.; Gomes, J. F. S.; Alvarenga, A. P. D.; Borges, P. P.; Araujo, T. O.

2018-03-01

Holmium oxide solution was prepared as a candidate of certified reference material for spectrophotometer wavelength scale calibration. Here is presented the necessary steps for evaluation of the uncertainty and the establishment of metrological traceability for the production of this material. Preliminary results from the first produced batch are shown.

Binding of Pentaammineruthenium(II) Residues to the Tris(bipyrazine)ruthenium(II) Cation.

Science.gov (United States)

1987-08-01

de Quimica , Universidade de Sao Paulo, CP 20780, Sao Paulo, SP, Brazil and Department of Chemistry, York University, North York, Ontario, Canada M3J...absorption spectra in the near-infrared region were obtained with a Cary 1 7 spectrophotometer, with the samples dissolved in D20. Nuclear magnetic

Nigerian Journal of Biotechnology (Vol. 33)

African Journals Online (AJOL)

Ladaf 2

The average egg laid per protocol. The purity and concentration of the extracted year ranges between 200 – 250 eggs. DNA were determined using Nano-drop. This increasing interest in genetics and animal spectrophotometer. breeding has led to several researches on how to improve both productive and reproductive ...

An automated wavelength selection for flame spectroscopy

International Nuclear Information System (INIS)

Hurteau, M.; Mislan, J.P.; Ashley, R.W.

1976-01-01

A simple electro-mechanical programming system is described for use with a flame spectrophotometer. Its application for automated sequential multi-element analysis is illustrated. Reproducibility of wavelength settings are within +-0.5 A. Precision and sensitivities are at least as good as those obtained for single element determinations. (author)

Use of Strychnos nux-vomica (Azraqi) seeds in unani system of ...

African Journals Online (AJOL)

It has been found that the detoxification processes studied reduce the strychnine content, as determined either by using uv-vis spectrophotometer or HPLC, present in Strychnos nux vomica seeds which is responsible for Strychnos nux vomica toxicity. The decrease in strychnine amount was best when the seeds were ...

One-pot synthesis of an Mn(III)–Cu(II)–Mn(III) trinuclear ...

Indian Academy of Sciences (India)

development of new materials with novel electronic properties.2 A common strategy to obtain such hetero- bimetallic ... Electronic spectra were recorded with a. UV-101PC/UV/Vis–NIR spectrophotometer (Shima- ..... Grants Commission, Government of India for the infrastructure facility at the University of Hydera- bad under ...

Trace Elements as Indicators of Quality of Drinking Water in Offa ...

African Journals Online (AJOL)

This study involved the determination of trace elements in drinking water in Offa Metropolis. Drinking water samples were collected from tap, well, borehole, stream and sachet water and analysed for Cr, Co, Cu, Fe, Mg and Mn using Atomic Absorption Spectrophotometer. The results obtained show the concentration ranges ...

Gold in semen: Level in seminal plasma and spermatozoa of normal ...

African Journals Online (AJOL)

The study was conducted to understand the amount of gold in semen of normal and different infertile conditions. Gold was estimated in normal (n38) and pathological conditions (n86) by employing Atomic Absorption Spectrophotometer. Gold level observed in seminal plasma was as follows: in normozoospermia (n38) ...

Analysis of mercury in Malaysian herbal preparations | Ang | Journal ...

African Journals Online (AJOL)

The rhizome of Smilax luzonensis is eaten as an aphrodisiac in the Malaysian community. This study was conducted to analyse the mercury content of 100 pharmaceutical dosage forms of S. luzonensis that were purchased in the Malaysian market, using cold vapour atomic absorption spectrophotometer. Results show that ...

A method optimization study for atomic absorption ...

African Journals Online (AJOL)

A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring ...

Method development and validation of potent pyrimidine derivative by UV-VIS spectrophotometer.

Science.gov (United States)

Chaudhary, Anshu; Singh, Anoop; Verma, Prabhakar Kumar

2014-12-01

A rapid and sensitive ultraviolet-visible (UV-VIS) spectroscopic method was developed for the estimation of pyrimidine derivative 6-Bromo-3-(6-(2,6-dichlorophenyl)-2-(morpolinomethylamino) pyrimidine4-yl) -2H-chromen-2-one (BT10M) in bulk form. Pyrimidine derivative was monitored at 275 nm with UV detection, and there is no interference of diluents at 275 nm. The method was found to be linear in the range of 50 to 150 μg/ml. The accuracy and precision were determined and validated statistically. The method was validated as a guideline. The results showed that the proposed method is suitable for the accurate, precise, and rapid determination of pyrimidine derivative. Graphical Abstract Method development and validation of potent pyrimidine derivative by UV spectroscopy.

Coincident Observation of Lightning using Spaceborne Spectrophotometer and Ground-Level Electromagnetic Sensors

Science.gov (United States)

Adachi, Toru; Cohen, Morris; Li, Jingbo; Cummer, Steve; Blakeslee, Richard; Marshall, THomas; Stolzenberg, Maribeth; Karunarathne, Sumedhe; Hsu, Rue-Ron; Su, Han-Tzong;

Development of optimized detector/spectrophotometer technology for low background space astronomy missions

Science.gov (United States)

Jones, B.

1985-01-01

This program was directed towards a better understanding of some of the important factors in the performance of infrared detector arrays at low background conditions appropriate for space astronomy. The arrays were manufactured by Aerojet Electrosystems Corporation, Azusa. Two arrays, both bismuth doped silicon, were investigated: an AMCID 32x32 Engineering mosiac Si:Bi accumulation mode charge injection device detector array and a metal oxide semiconductor/field effect transistor (MOS-FET) switched array of 16x32 pixels.

Evaluation of portable near infrared spectrophotometer to stage maturity in channel catfish

Science.gov (United States)

Gonadal maturity of channel catfish varies within the same cohort of fish. Female channel catfish with superior maturity need to be identified and staged for higher success to induce spawn wit ovulating hormones to produce channel x blue hybrid catfish fry in hatcheries. Maturation is not synchron...

Determination of Iron Content in Iron Deficiency Drugs by UV-Visible Spectrophotometer

Directory of Open Access Journals (Sweden)

Isam Eldin Hussein Elgailani

2017-07-01

Full Text Available The objective of this work was to validate a simple, precise and accurate spectrophotometric method for the determination of iron in the iron deficiency drugs, namely are Feroglobin B12, Ferose-F and Ferose. The proposed method is based on the reaction of iron with ammonium thiocyanate after the wet digestion of the drugs under study with HNO3 and H2O2.  Effects of pH, temperature, standing time and thiocyanate concentration on the determination of iron in drugs containing iron have been investigated. The λmax was 430 nm and the molar absorptivity of 0.0399 L mol-1 cm-1. The linear regression was in the range 0.5 - 60 μg/mL for iron content in hemoglobin. The detection limit and the limit of quantification were found to be 0.040 and 0.122 µg mL-1 for the iron respectively, and with a linear regression correlation coefficient of 0.998. Recovery measurements ranged from 99.63-100.20%. This method is simple and fast can be used for the determination of iron in the iron deficiency drugs in pharmaceutical laboratories. DOI: http://dx.doi.org/10.17807/orbital.v9i3.953

Band gap determination of Ni–Zn ferrites

Indian Academy of Sciences (India)

Unknown

Nanocomposites of Ni–Zn with copolymer matrix of aniline and formaldehyde in presence of varying concentrations of zinc ions have been ... spectrophotometer at room temperature. From the analysis of reflection spectra, nanocomposites of .... the nanocomposites of. Ni1–xZnxFe2O4. In some of the ternary semiconductors.

Influence of mine drainage on water quality along River Nyaba in ...

African Journals Online (AJOL)

The cations and trace elements were determined by ICP- MS while the anions were measured by spectrophotometer and titration methods. Field parameters such as pH, temperature and conductivity were determined in the field using standard equipment. The results show that the water is acidic to moderately acidic (pH ...

Escherichia coli growth modeling using neural network | Shamsudin ...

African Journals Online (AJOL)

technique that has the ability to predict with efficient and good performance. Using NARX, a highly accurate model was developed to predict the growth of Escherichia coli (E. coli) based on pH water parameter. The multiparameter portable sensor and spectrophotometer data were used to build and train the neural network.

A Laboratory Application of Microcomputer Graphics.

Science.gov (United States)

Gehring, Kalle B.; Moore, John W.

1983-01-01

A PASCAL graphics and instrument interface program for a Z80/S-100 based microcomputer was developed. The computer interfaces to a stopped-flow spectrophotometer replacing a storage oscilloscope and polaroid camera. Applications of this system are discussed, indicating that graphics and analog-to-digital boards have transformed the computer into…

Optical characteristics of crystalline antimony sulphide (Sb 2 S 3 ...

African Journals Online (AJOL)

This paper presents the important optical characteristics of crystalline Sb2S3 film deposited on glass substrate using solution growth technique at 300k. These characteristics were analyzed using PYEUNICAM SP8-100 spectrophotometer in the range of UV-VIS-NIR while the morphology and the structural composition were ...

Distributed Read-out Imaging Device array for astronomical observations in UV/VIS

NARCIS (Netherlands)

Hijmering, R.A.

2009-01-01

STJ (Superconducting Tunneling Junctions) are being developed as spectro-photometers in wavelengths ranging from the NIR to X-rays. 10x12 arrays of STJs have already been successfully used as optical imaging spectrometers with the S-Cam 3, on the William Hershel Telescope on La Palma and on the

Atomic absorption spectrometer readout and data reduction using the LSI-11 microcomputer

International Nuclear Information System (INIS)

Allen, M.J.; Wikkerink, R.W.

1978-01-01

Some common instruments found in the chemistry laboratory have analog chart recorder output as their primary data readout media. Data reduction from this medium is slow and relatively inaccurate. This paper describes how to interface a single LSI-11 microcomputer to PERKIN-ELMER models 603 and 303 Atomic Absorption Spectrophotometers

Spectrophotometric Determination of Nitrate and Phosphate Levels ...

African Journals Online (AJOL)

Twelve drinking water samples from boreholes were collected from various sampling sites around the vicinity of Kura irrigated farmlands using polythene plastic containers and were analysed for the nitrate and phosphate levels using uV – visible spectrophotometer. From the results, it was found that all the samples had ...

SHORT COMMUNICATION REACTION OF NITRILIMINES WITH 1,4 ...

African Journals Online (AJOL)

Preferred Customer

spectra were measured as potassium bromide pellets using a Satellite 3000 mid infrared spectrophotometer. The 1H NMR and 13C NMR spectra were recorded on a Bruker AM 300. MHz spectrometer at room temperature in DMSO-d6 solution using tetramethylsilane (TMS) as internal reference. Chemical shifts were ...

A DNA Melting Exercise for a Large Laboratory Class

Science.gov (United States)

Levine, Lauren A.; Junker, Matthew; Stark, Myranda; Greenleaf, Dustin

2015-01-01

A simple and economical experimental setup is described that enables multiple individuals or groups within a laboratory class to measure the thermal melting of double stranded DNA simultaneously. The setup utilizes a basic spectrophotometer capable of measuring absorbance at 260 nm, UV plastic cuvettes, and a stirring hot plate. Students measure…

Lead, zinc and pH concentrations of Enyigba soils in Abakaliki Local ...

African Journals Online (AJOL)

The concentrations of lead (Pb) and zinc (Zn) were quantitatively determined in surface and sub-surface soils in Enyigba, Ebonyi State, Nigerian's major lead mining area using atomic absorption spectrophotometer. pH status of the soils was similarly determined. The survey was conducted to establish a base line pollution ...

Sorghum cobalt analysis on not determined wave length with atomic ...

African Journals Online (AJOL)

This study was to know the better wave length on measuring cobalt content in forage sorghum hybrid (Sorghum bicolor) with an atomic absorption spectrophotometer. The analysis was on background correction mode with three wave lengths; 240.8, 240.7 (determined wave length or recommended wave length) and 240.6 ...

Research Article Special Issue

African Journals Online (AJOL)

pc

2017-10-17

Oct 17, 2017 ... 1Faculty of Electrical Engineering, Universiti Teknologi MARA, 23000 ... spectrophotometer to measure the protein concentration. ... root through any exposed tissue in the stem or branch resulting from wounds. ... Where A is the absorbance, ε is the molar absorption coefficient (M−1cm−1), l is the cell.

Spectroscopy, Understanding the Atom Series.

Science.gov (United States)

Hellman, Hal

This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

Delonix regia

African Journals Online (AJOL)

NICOLAAS

cate using Atomic Absorption Spectrophotometer (Buck 210. VGP). 2.4. Amino Acid Composition. Amino acid composition of the seeds was determined using modified method .... increase of which leads to toxicity, so their presence in D. regia shows it is a .... for the production of food and in cosmetic applications.4,36 Oleic.

Quality assessment of drinking water in Temeke District (part II ...

African Journals Online (AJOL)

Water quality studied includes pH, chloride, nitrate and total hardness levels. The concentrations of total hardness in mg CaCO3/L and chloride were obtained by titration method while the nitrate concentration levels were determined by spectrophotometer. Tap water was found to be of high quality than other sources in ...

Development and performance of on-line uranium analyzers

International Nuclear Information System (INIS)

Ofalt, A.E.; O'Rourke, P.E.

1985-10-01

A diode-array spectrophotometer and and x-ray fluorescence analyzer were installed online in a full-scale prototype facility to monitor uranium loading and breakthrough of ion exchange columns. Uranium concentrations of 10 ppM in uranyl nitrate solutions can be detected online to improve process control and material accountability. 9 figs

Light-Induced Copper(II) Coordination by a Bicyclic Tetraaza Chelator through a Ligand-to-Metal Charge-Transfer Reaction

DEFF Research Database (Denmark)

Holm-Jørgensen, Jacob Rørdam; Jensen, Mikael; Bjerrum, Morten J.

2011-01-01

coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu2+ and [24.31]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation...

Structural, magnetic and photocatalytic characterization of Bi1 ...

Indian Academy of Sciences (India)

47

The UV–Vis absorption spectra were recorded on a Shimadzu UV-Vis-52550 spectrophotometer with the wavelength range of 200–700 nm. Photocatalytic activity of the synthesized Bi1-xLaxFeO3 nanoparticles was evaluated by the degradation of methylene blue (MB) in aqueous solution under visible light radiation.

Dose reader of dosimetric foil; Czytnik dawki folii dozymetrycznej

Energy Technology Data Exchange (ETDEWEB)

Machaj, B.; Strzalkowski, J.; Smolko, K.

1997-12-31

Read out the absorbance of a dosimetric foil is accomplished by two beam spectrophotometer. Such a solution makes possible the compensation of light source instabilities and ensures higher stability of the dose reader. The error of absorbance measurement caused by the instabilities does not exceed 0.0004 A. (author). 3 refs, 3 figs.

Simple picrate method for the determination of cyanide in cassava ...

African Journals Online (AJOL)

The red coloured complex on the strips was extracted with 50% ethanol solution and the absorbance of the extract was measured at 510nm using a spectrophotometer. The method was reproducible and cyanide as low as 1 microgram could be determined. Cyanide levels of all the cassava varieties tested were higher than ...

Physico-chemical, functional and processing attributes of some ...

African Journals Online (AJOL)

ajl yemi

2011-12-26

Dec 26, 2011 ... commercial processing and marketing chain is generally inevitable and ... was measured by a digital caliper (0 to 150 mm, China) with an accuracy of .... Spectrophotometer (GBC-932 Australlia), whereas Na and .... era ls (m g. /1. 0. 0 g. ) Figure 4. Correlation between ash (%) and total minerals (mg/100 g).

Untitled

Indian Academy of Sciences (India)

Absorption spectra were taken with the UVISPEK spectro-photometer and pH was measured with a Macbeth pH meter. Fluo- rescence spectra were recorded with a Bellingham Stanley monochromator and 931 A photomultiplier arrangement. The exciting radiation (3650A) from a 125-watt Philips black-light lamp, run on a ...

Applicability Of A Semi-Automated Clinical Chemistry Analyzer In Determining The Antioxidant Concentrations Of Selected Plants

Directory of Open Access Journals (Sweden)

Allan L. Hilario

2017-07-01

Full Text Available Plants are rich sources of antioxidants that are protective against diseases associated to oxidative stress. There is a need for high throughput screening method that should be useful in determining the antioxidant concentration in plants. Such screening method should significantly simplify and speed up most antioxidant assays. This paper aimed at comparing the applicability of a semi-automated clinical chemistry analyzer Pointe Scientific MI USA with the traditional standard curve method and using a Vis spectrophotometer in performing the DPPH assay for antioxidant screening. Samples of crude aqueous leaf extract of kulitis Amaranthus viridis Linn and chayote Sechium edule Linn were screened for the Total Antioxidant Concentration TAC using the two methods. Results presented in mean SD amp956gdl were compared using unpaired Students t-test P0.05. All runs were done in triplicates. The mean TAC of A. viridis was 646.0 45.5 amp956gdl using the clinical chemistry analyzer and 581.9 19.4 amp956gdl using the standard curve-spectrophotometer. On the other hand the mean TAC of S. edule was 660.2 35.9 amp956gdl using the semi-automated clinical chemistry analyzer and 672.3 20.9 amp956gdl using the spectrophotometer. No significant differences were observed between the readings of the two methods for A. viridis P0.05 and S. edible P0.05. This implies that the clinical chemistry analyzer can be an alternative method in conducting the DPPH assay to determine the TAC in plants. This study presented the applicability of a semi-automated clinical chemistry analyzer in performing the DPPH assay. Further validation can be conducted by performing other antioxidant assays using this equipment.

coupling the image analysis and the artificial neural networks to ...

African Journals Online (AJOL)

Y. Mahdi, L. Mouhi, N. Guemras and K. Daoud

mixture, we use the method of Image processing, figure 2. Fig. 2. Schematic diagram of the image acquisition setup. The pictures taken during the processes of mixture at the wall of the blenders have been analyzed using ImageJ software and have been validated with the results obtained by the. UV-vis spectrophotometer ...

Investigation of methods to prepare carbon foils and to determine their thicknesses

International Nuclear Information System (INIS)

Xu Guoji; Guan Shouren; Luo Xinghua; Meng Xiangjin

1988-01-01

The development and study of methods to prepare carbon foils and to determine their thicknesses are described. The methods of making carbon foils consist of carbon-arc evaporation, resistance heating, electron bombardment, cracking ethylene and centrifugal precipitation. Weighing, α-particle measurement, Rutherford backscattering and spectrophotometer are used to determine the thickness of carbon foils

Heavy metals content in the stem bark of Detarium microcarpum ...

African Journals Online (AJOL)

The heavy metal analysis was carried out on the stem bark of D. microcarpum using an atomic absorption spectrophotometer (AAS). The heavy metals screened for include: lead, chromium, manganese, zinc and iron. The levels of manganese, zinc and iron were 13.91, 4.89 and 21.89 mg/L respectively. These heavy metals ...

The Challenge '88 Project: Interfacing of Chemical Instruments to Computers.

Science.gov (United States)

Lyons, Jim; Verghese, Manoj

The main part of this project involved using a computer, either an Apple or an IBM, as a chart recorder for the infrared (IR) and nuclear magnetic resonance (NMR) spectrophotometers. The computer "reads" these machines and displays spectra on its monitor. The graphs can then be stored for future reference and manipulation. The program to…

Estimation of arsenic in nail using silver diethyldithiocarbamate method

Directory of Open Access Journals (Sweden)

Habiba Akhter Bhuiyan

2015-08-01

Full Text Available Spectrophotometric method of arsenic estimation in nails has four steps: a washing of nails, b digestion of nails, c arsenic generation, and finally d reading absorbance using spectrophotometer. Although the method is a cheapest one, widely used and effective, it is time consuming, laborious and need caution while using four acids.

Screening of degradative plasmids from Arthrobacter sp. HW08 and ...

African Journals Online (AJOL)

Administrator

2011-06-08

Jun 8, 2011 ... Media were solidified, if necessary, by the addition of 15 g agar ... genome extraction reagent kit, plasmid DNA fast extraction kit and. DNA segments ... spectrophotometer (Spectronic Instruments, Rochester, NY) and. SW content .... cultivation on LB slant for 100 times at 30 °C for 2 days, it was found that ...

Analysis of some metals in some brands of tea sold in Kano, Nigeria ...

African Journals Online (AJOL)

Tea leaves can be a source of mineral components and trace elements as well as some undesirable substances due to exposure to the environment. In this study, Mg, Fe, Ca, Zn, Mn, Cu and Pb were analyzed by Atomic Absorption spectrophotometer (AAS), K and Na were also determined by flame photometer. Among the ...

DARPA Antibody Technology Program Standardized Test Bed for Antibody Characterization: Characterization of an MS2 ScFv Antibody

Science.gov (United States)

2016-03-01

2 2.2 UV –Visible Spectrophotometry...3 M phosphoric acid or 3 M sodium hydroxide [Sigma-Aldrich] as necessary), and overhead pressure of 1 psi. When the OD inside the 100 L fermentor...chromatography media (GE Healthcare). 2.2 UV –Visible Spectrophotometry A NanoDrop ND-1000 spectrophotometer (Thermo Scientific; Waltham, MA

Palaemon pacijicus (Stimpson) in eastern Cape tidal

African Journals Online (AJOL)

1984-09-25

Sep 25, 1984 ... seasonally with peak numbers and biomass found in summer ... One part of the programme dealt with the tidal pool ... pools sampled. Unicam spectrophotometer at 458 run. A dilution series was made for each batch of concentrate used. A domestic water meter was coupled to the outlet of a portable pump ...

Extraction and Purification of Flavonoids from Radix Puerariae

African Journals Online (AJOL)

content of puerarin and flavonoids in the samples were tested by a HPLC and a UV-Vis. Spectrophotometer, respectively. ... the weight of the crude drug), the volume of loading sample is 2 BV (bed volume). The mobile phases of desorption are ... flavonoids, they have a variety of biological activities [1-3] including improving ...

Spectrophotometric determination of lisinopril in three simulated ...

African Journals Online (AJOL)

The methods were based on dissolution of standard lisinopril powder or extraction of the drug from tablet formulation using three dissolution media (0.1 M HCl, phosphate buffer pH 6.8 and phosphate buffer pH 7.4) respectively as solvents. Each resulting extract was filtered and scanned using UV/Vis spectrophotometer ...

Antibacterial and antioxidant properties of macrocyclic Schiff bases ...

African Journals Online (AJOL)

CLEMENT O BEWAJI

Electronic spectra of the compounds were recorded on a digital spectrophotometer. ... Acetylacetone in ethanol with the solutions of Semicarbazide hydrochloride in hot water ... pre-incubated for 1 h at room temperature and incubated at 37°C for 24 h.8 Ofloxacin was used as standard. 2.4 Scavenging of nitric oxide. Sodium ...

Synthesis and characterization of irradiated injectable bone substitute paste based on hydroxyapatite

International Nuclear Information System (INIS)

Yessy Warastuti; Basril Abbas

2011-01-01

Synthesis and characterization of hydroxyapatite, chitosan and hydroxypropyl methylcellulose (HPMC) composite in injectable paste form have been done. The composite was synthesized by stirring hydroxyapatite, chitosan and HPMC until homogen. IBS paste was irradiated at the dose of 25 kGy (sterile dose). Characterization of IBS paste was conducted by measuring of the water content, identification of functional group with Fourier Transform Infra Red Spectrophotometer (FTIR), and identification of sample morphology with Scanning Electron Microscope Energy Dispersive Spectrophotometer (SEM EDS). The result showed that the water content of irradiated sample was higher than unirradiated sample due to water radiolysis. Several specific bands of IBS paste were identified, i.e., carbonate (CO 3 2- ), at 1420 cm -1 , phosphate (PO 4 3- ) at 1043 cm -1 , 605 cm -1 , 568 cm -1 and chitosan (NH 2 ) at 1599 cm -1 . There is no significant difference in absorbed band between irradiated and unirradiated samples. IBS paste has a microstructure with the size of 0.05 – 0.1 μm. Electron beam irradiation did not change the structure and morphology of sample. (author)

Procedure for measuring simultaneously the solar and visible properties of glazing with complex internal or external structures.

Science.gov (United States)

Gentle, A R; Smith, G B

2014-10-20

Accurate solar and visual transmittances of materials in which surfaces or internal structures are complex are often not easily amenable to standard procedures with laboratory-based spectrophotometers and integrating spheres. Localized "hot spots" of intensity are common in such materials, so data on small samples is unreliable. A novel device and simple protocols have been developed and undergone validation testing. Simultaneous solar and visible transmittance and reflectance data have been acquired for skylight components and multilayer polycarbonate roof panels. The pyranometer and lux sensor setups also directly yield "light coolness" in lumens/watt. Sample areas must be large, and, although mainly in sheet form, some testing has been done on curved panels. The instrument, its operation, and the simple calculations used are described. Results on a subset of diffuse and partially diffuse materials with no hot spots have been cross checked using 150 mm integrating spheres with a spectrophotometer and the Air Mass 1.5 spectrum. Indications are that results are as good or better than with such spheres for transmittance, but reflectance techniques need refinement for some sample types.

Use of photothermal deflection spectrometry (PDS) for studies of analytes in aqueous solutions

International Nuclear Information System (INIS)

Bohnert, B.; Faubel, W.; Ache, H.J.

1990-01-01

A crossed-beam photothermal deflection spectrophotometer (PSD) instrument was built, evaluated and applied to the determination of lanthanide neodymium. A dye laser filled with rhodamine 6 G and pumped by an argon ion laser at 514 nm was operated with outputs between 4 and 500 mW at the cuvette position and chopped at 2 Hz. The deflection of a He-Ne probe laser beam, crossing the exciting dye laser, was measured by a two-dimensional position sensitive device and two lock-in amplifiers. The setup was evaluated with a solid carbon sample and the liquids toluene and Nd 3+ /HClO 4 . A calibration curve for Nd 3+ in HClO 4 was obtained and the limit of detection (LOD) for Nd 3+ was determined to be 2x10 -6 mol/l. This LOD is, on the one hand, by 2 orders of magnitudes lower than the value obtained with the Cary 2400 spectrophotometer and, on the other hand, this transverse PDS technique is highly competitive to collinear thermal lensing and laser-induced photoacoustic spectroscopy. (orig.)

Optical characterization of n=1.03 silica aerogel used as radiator in the RICH of HERMES

CERN Document Server

Aschenauer, E; Capitani, G P; Carter, P; Casalino, C; Cisbani, E; Coluzza, C; De Leo, R; De Sanctis, E; De Schepper, D; Dzhordzhadze, V; Filippone, B W; Frullani, S; Garibaldi, F; Hansen, J O; Hommez, B; Iodice, M; Jackson, H E; Kaiser, R; Kanesaka, J; Lagamba, L; Muccifora, V; Nappi, E; Nowak, Wolf-Dieter; O'Neill, T G; Potterveld, D; Ryckbosch, D; Sakemi, Y; Sato, F; Schwind, A; Suetsugu, K; Shibata, T A; Thomas, E; Tytgat, M; Urciuoli, G M; Kerckhove, K V D; Vyver, R V D; Yoneyama, S; Zhang, L F

2000-01-01

The optical properties of silica aerogel tiles with a refractive index of 1.03 and dimensions 11x11x1 cm sup 3 , produced by the Matsushita Electric Works (Japan), have been measured in the wavelength range from 200 to 900 nm. The tiles are used as one of the two radiators of the ring imaging Cherenkov counter of the HERMES experiment at DESY-HERA. The transmittance of light has been measured on 200 tiles by means of a double beam spectrophotometer. The light transflectance and reflectance have been measured on one tile by means of a single-beam spectrophotometer and an integrating reflecting sphere. Typical values of the measured transmittances at a wavelength lambda=400 nm are around 0.67. The measured transflectance increases almost linearly from 0.4 to 0.96 in the interval 200-300 nm, and remains nearly constant at the value 0.95 in the complementary lambda-range. The measured reflectance, mostly confined below 400 nm, is completely interpretable as backscattering from inside the aerogel, revealing an abs...

Automated monosegmented flow analyser. Determination of glucose, creatinine and urea.

Science.gov (United States)

Raimundo Júnior, I M; Pasquini, C

1997-10-01

An automated monosegmented flow analyser containing a sampling valve and a reagent addition module and employing a laboratory-made photodiode array spectrophotometer as detection system is described. The instrument was controlled by a 386SX IBM compatible microcomputer through an IC8255 parallel port that communicates with the interface which controls the sampling valve and reagent addition module. The spectrophotometer was controlled by the same microcomputer through an RS232 serial standard interface. The software for the instrument was written in QuickBasic 4.5. Opto-switches were employed to detect the air bubbles limiting the monosegment, allowing precise sample localisation for reagent addition and signal reading. The main characteristics of the analyser are low reagent consumption and high sensitivity which is independent of the sample volume. The instrument was designed to determine glucose, creatinine or urea in blood plasma and serum without hardware modification. The results were compared against those obtained by the Clinical Hospital of UNICAMP using commercial analysers. Correlation coefficients among the methods were 0.997, 0.982 and 0.996 for glucose, creatinine and urea, respectively.

Feasibility of Uranium Concentration Measurements for H Canyon Tank 16.7

International Nuclear Information System (INIS)

Lascola, R.J.

2003-01-01

Savannah River Technology Center (SRTC) evaluated the feasibility of using the H Canyon on-line diode array spectrophotometer to measure uranium concentrations in Tank 16.7. On-line measurements will allow an increase in highly enriched uranium (HEU) production by removing delays associated with off-line measurements. The instrument must be able to measure uranium at concentrations below 1.0 g/L with an uncertainty no greater than 0.3 g/L. SRTC determined that the system has a limit of quantitation of 0.15 g/L. At concentrations of 0.5 and 1.0 g/L, the spectrometer uncertainty is 0.10 g/L. No design changes, such as an increase in flow cell path length, are required to obtain this performance. Expected levels of iron in Tank 16.7 solutions will not interfere with the measurement. The CHEMCHEK method should not be used for confirmatory analysis, as it contributes excessively to the overall uncertainty of the measurement. SRTC expects that the spectrophotometer will meet the measurement requirements for Tank 16.7

Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater.

Science.gov (United States)

Lepot, Mathieu; Aubin, Jean-Baptiste; Bertrand-Krajewski, Jean-Luc

2013-01-01

Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.

Quantitative analysis of properties of petroleum mixtures by near infrared spectroscopy; Analise quantitativa de propriedades de misturas de petroleos via espectrofotometria no infravermelho proximo

Energy Technology Data Exchange (ETDEWEB)

Santos, Leila M.; Silva, Elisangela B.; Fortuny, Montserrat; Dariva, Claudio; Santos, Alexandre F. [Universidade Tiradentes (UNIT), Aracaju, SE (Brazil). Instituto de Tecnologia e Pesquisa (ITP); Araujo, Augusto M. [Siemens Brazil, Rio de Janeiro, RJ (Brazil); Coutinho, Raquel C.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

An experimental study is carried out aiming to develop a method of quantitative analysis of properties of petroleum mixtures, such as water and asphaltene contents, heavy oil concentration and viscosity based on the use of a NIR spectrophotometer. A strategy of generation of crude oil mixtures with known properties was developed to help calibrating the NIR spectrophotometer. Petroleum mixtures involving 2 or 3 oils under known ratios were prepared based on a set of different light and heavy Brazilian crude oil samples. Moreover, experimental data of 5 binary mixtures were also assembled into a data set named multi-compound. Results indicated that excellent calibration models can be obtained for binary mixtures with correlation coefficient (R{sup 2}) greater than 99% for water and asphaltene contents, viscosity and heavy oil concentration. For ternary systems, excellent correlations (R{sup 2}>99%) can be attained for asphaltene and heavy oil contents. Finally for the multi-compound data set, the asphaltene content was the only property that resulted in R{sup 2}>99%, which demonstrates the adequacy of the NIR technique for assessing this property. (author)

Ground and river water quality monitoring using a smartphone-based pH sensor

Directory of Open Access Journals (Sweden)

Sibasish Dutta

2015-05-01

Full Text Available We report here the working of a compact and handheld smartphone-based pH sensor for monitoring of ground and river water quality. Using simple laboratory optical components and the camera of the smartphone, we develop a compact spectrophotometer which is operational in the wavelength range of 400-700 nm and having spectral resolution of 0.305 nm/pixel for our equipment. The sensor measures variations in optical absorption band of pH sensitive dye sample in different pH solutions. The transmission image spectra through a transmission grating gets captured by the smartphone, and subsequently converted into intensity vs. wavelengths. Using the designed sensor, we measure water quality of ground water and river water from different locations in Assam and the results are found to be reliable when compared with the standard spectrophotometer tool. The overall cost involved for development of the sensor is relatively low. We envision that the designed sensing technique could emerge as an inexpensive, compact and portable pH sensor that would be useful for in-field applications.