Reaction Chamber and Cathode Configurations in Arc Production of Fullerenes

1994 ◽  
Vol 359 ◽  
Author(s):  
E. Pasqualini ◽  
C. Podesta ◽  
A. GarcÍa ◽  
A. Rafael ◽  
S. Dengra ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Reaction Chamber ◽  
Decomposition Rates ◽  
Deposit Formation ◽  
Cathodic Deposit ◽  
Visible Spectra ◽  
Uv Visible ◽  
Different Origins ◽  
Equivalent Conditions

ABSTRACTThe reaction chamber in the arc production of fullerenes was redesigned with a nozzle surrounding the decomposition zone to allow for clean collection of soot in a filtering cartridge. Quantitative analysis in the region of 300–430 nm in UV-visible spectra permits determination of the abundance of C60 and C70 in the soot. Calibrated curves of absorptivity for both pure fullerenes were employed. In equivalent conditions of current and pressure, electrographites of different origins have different decomposition rates and yields. A mechanism to interpret the cathodic deposit formation is proposed. Decomposition inside a closed cathodic cylinder yields 100% deposit.

scholarly journals Analisis Senyawa β-Karoten pada Buah Pepaya (Carica papaya L.) Asal Kabupaten Konawe Selatan, Provinsi Sulawesi Tenggara

2021 ◽  
Vol 4 (2) ◽  
pp. 1-7
Author(s):  
Irman Idrus ◽  
Sabda Wahab ◽  
Andi Fitrah Nugraha ◽  
Syaiful Bachri
Keyword(s):  
Quantitative Analysis ◽  
The Body ◽  
Test Results ◽  
Carotene Content ◽  
Test Parameter ◽  
Qualitative Test ◽  
Uv Visible ◽  
Planting Method ◽  
Β Carotene

South Konawe District at Southeast Sulawesi Province is a producer of agriculture such as Papaya fruit ranging from 1168 quintals each year. Papaya fruit contains β-carotene which plays an important role in the formation of vitamin A in the body. This research was conducted to determine the β-carotene content of papaya fruit by using variables planting method, fruitage, and fruit condition. The mashed fruit was extracted using n-hexane: acetone: ethanol (2: 1: 1) v/v, then separated from polar and non-polar solutions. Qualitative analysis was carried out using the Carr-Price method and quantitative analysis or determination of β-carotene levels using the UV-Visible spectrophotometric method λ = 452.0 nm. The qualitative test results showed that the papaya fruit in the papaya fruit obtained by cultivation and growing wild with each variable half-ripe, ripe, and not fresh papaya identified the presence of β-carotene. The results of quantitative analysis of β-carotene levels in cultivated papaya fruit were 1.76 μL, half-ripe 1.32 μL, and cultivated young papaya 1.22 μL. In wild ripe papaya 1.75 μL, wild half-ripe papaya 1.3 μL and wild young papaya 1.21 μL. There is an effect of each test parameter starting from the parameters of planting method, fruitage, and fruit condition on β-carotene content in papaya fruit.

Cellulose Nanofiber as Potential Absorbent Material for Chloride Ion

2021 ◽  
Vol 317 ◽  
pp. 263-269
Author(s):  
Muhammad Syukri Mohamad Misenan ◽  
Nurjahirah Janudin ◽  
Mas Amira Idayu ◽  
Mohd Nor Faiz Norrrahim ◽  
Siti Hasnawati Jamal ◽  
...  
Keyword(s):  
Low Cost ◽  
Cellulose Nanofibers ◽  
Chloride Ion ◽  
Absorption Capacity ◽  
Visible Spectra ◽  
Ft Ir ◽  
Uv Visible ◽  
Hcl Concentration ◽  
Hcl Solution

A simple, low cost and rapid analytical method for determination of HCl concentration after being treated with cellulose and cellulose nanofibers (CNF) is developed. This method is based on color intensity after the HCl solution is doped with sodium iodide (NaI). The color of HCl solution changes from colorless to yellow. The intensity of the color is measured by UV – Visible spectroscopy. The UV-Visible spectra of 0.15 M HCl treated with cellulose and cellulose nanofibers is reduced from its initial concentration. The CNF absorption capacity is higher as compared to cellulose. FT-IR analysis showed that there is interaction between C-H group from the CNF backboned and chloride ion from HCl solution.

scholarly journals Study of the β-Cyclodextrin Imipramine Hydrochloride Inclusion Complex and Determination of its Stability Constant (K) by UV-Visible Spectroscopy

2007 ◽  
Vol 4 (4) ◽  
pp. 550-558 ◽  
Author(s):  
Alamdar Ashnagar ◽  
Nahid Gharib Naseri ◽  
Bita Khanaki
Keyword(s):  
Stability Constant ◽  
Inclusion Complex ◽  
Visible Spectroscopy ◽  
Constant Amount ◽  
A Value ◽  
Visible Spectra ◽  
Imipramine Hydrochloride ◽  
Uv Visible ◽  
The Stability

In this research, the interactions of imipramine hydrochloride drug with β- cyclodextrin and the stability constant (K) of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. Solutions consisting of a known and constant amount of imipramine hydrochloride and varying amounts of β- cyclodextrin were prepared in 0.1 M phosphate buffer (pH 7.4). The final solutions had cyclodextrin concentrations between 0.0011 and 0.0153 M. UV-visible spectra of each solution was taken at λmax= 250 nm. The absorbances at this wavelength were recorded and plotted against cyclodextrin concentrations. From the graph, the concentrations of free and bound imipramine hydrochloride and free β-cyclodextrin were calculated using the Beer-Lambert law. From these data, the stability constant was calculated and a value of K=52.26±11.41 mol-1L was obtained. The magnitude of the stability constant is discussed in terms of the relative sizes and the chemical natures of β-cyclodextrin and imipramine hydrochloride.

N-confusedmeso-tetraaryl-substituted free-base porphyrins: determination of protonation and deprotonation constants in nonaqueous media

2015 ◽  
Vol 19 (01-03) ◽  
pp. 251-260 ◽  
Author(s):  
Zhongping Ou ◽  
Xueyan Chen ◽  
Lina Ye ◽  
Songlin Xue ◽  
Yuanyuan Fang ◽  
...  
Keyword(s):  
Tautomeric Form ◽  
Equilibrium Constants ◽  
Single Step ◽  
Free Base ◽  
Nonaqueous Media ◽  
Tautomeric Forms ◽  
Visible Spectra ◽  
Phenyl Rings ◽  
Uv Visible

The protonation and deprotonation reactions for a series N-confused meso-tetraaryl-substituted free-base porphyrins containing electron-donating or electron-withdrawing substituents was monitored in CHCl3and DMF by UV-visible spectroscopy during titrations with trifluoroacetic acid or tetra-n-butylammonium hydroxide. The spectroscopic data was also used to calculate equilibrium constants for these reactions. The examined compounds are represented as (XPh)4NCPH2, where "NCP" represents the N-confused porphyrin π-conjugated macrocycle and X is a CH3O , CH3, H or Cl para-substituent on the four meso-phenyl rings (Ph) of the compound. The porphyrins can exist in two tautomeric forms depending upon the solvent and each tautomer undergoes two stepwise protonation reactions leading to formation of the mono- and bis-protonated porphyrins, [(XPh)4NCPH3]+and [(XPh)4NCPH4]2+. A single step deprotonation is observed for the same compounds in DMF and the product is assigned as [(XPh)4NCPH]-. Comparisons are made between UV-visible spectra of the protonated, neutral and deprotonated forms of the porphyrin and the effect of the porphyrin ring substituents and tautomeric form of the neutral porphyrin on the UV-visible spectra and protonation constants is discussed along with data from DFT calculations.

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Infrared and UV-visible spectra of layer semiconductors Gas, GaSe and GaTe

1977 ◽  
Vol 38 (10) ◽  
pp. 1293-1299 ◽  
Author(s):  
U. Giorgianni ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta ◽  
G. Vermiglio
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Application of EDS Technique for OSP Film Thickness Measurement

2006 ◽  
Author(s):  
Prong Kongsubto ◽  
Sirarat Kongwudthiti
Keyword(s):  
Thin Film ◽  
Quantitative Analysis ◽  
Joint Strength ◽  
Critical Factor ◽  
Thickness Measurement ◽  
Ic Manufacturing ◽  
And Control ◽  
Film Thickness Measurement ◽  
Non Destructive

Abstract Organic solderability preservatives (OSPs) pad is one of the pad finishing technologies where Cu pad is coated with a thin film of an organic material to protect Cu from oxidation during storage and many processes in IC manufacturing. Thickness of OSP film is a critical factor that we have to consider and control in order to achieve desirable joint strength. Until now, no non-destructive technique has been proposed to measure OSP thickness on substrate. This paper reports about the development of EDS technique for estimating OSP thickness, starting with determination of the EDS parameter followed by establishing the correlation between C/Cu ratio and OSP thickness and, finally, evaluating the accuracy of the EDS technique for OSP thickness measurement. EDS quantitative analysis was proved that it can be utilized for OSP thickness estimation.

HPLC-UV Method for Determination of Famotidine from Pharmaceutical Products

2018 ◽  
Vol 69 (2) ◽  
pp. 297-299
Author(s):  
Adriana Nita ◽  
Delia Mirela Tit ◽  
Lucian Copolovici ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Dana Maria Copolovici ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Quantitative Analysis ◽  
Linear Response ◽  
Mobile Phase ◽  
Acetic Acid Solution ◽  
Pharmaceutical Products ◽  
Quantification Limit ◽  
Validation Parameters ◽  
Hplc Analyses

The aim of this study was to develop and validate a rapid, accurate, and exact method for the quantitative determination of famotidine in pharmaceutical products. The HPLC analyses were performed by using a mobile phase containing methanol:1% acetic acid solution=30:7 (v/v), at a flow rate of 0.4 mL/min.The total time of the method was 10 min, and the retention time of famotidine was 4.16 min. The detection was evaluated at l=267 nm. The method has been validated by using different validation parameters. The linear response of the detector for famotidine peak area was observed at concentrations ranging from 0.1 to 0.0001 mg mL-1 , resulting in a correlation coefficient of 0.99998. The values of the detection limit and of the quantification limit are 0.00048 mg mL-1 and 0.00148 mg mL-1, respectively. The method proposed allowed accurate (with a relative error of less than 2%) and precise (RSD values less than 2.0%) determination of famotidine content in pharmaceutical products and can be used for its rapid quantitative analysis.

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