scholarly journals Surface Modification of Fly Ash for Active Catalysis

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Deepti Jain ◽  
Renu Hada ◽  
Ashu Rani
Keyword(s):  
Fly Ash ◽  
Heterogeneous Catalysts ◽  
Chemical Activation ◽  
Alumina Content ◽  
Precipitation Method ◽  
Solid Base ◽  
Thermally Activated ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Different Temperatures

Fly ash based effective solid base catalyst (KF/Al2O3/fly ash473, KF/Al2O3/fly ash673, and KF/Al2O3/fly ash873) was synthesized by loading KF over chemically and thermally activated fly ash. The chemical activation was done by treating fly ash with aluminum nitrate via precipitation method followed by thermal activation at 650°C to increase the alumina content in fly ash. The increased alumina content was confirmed by SEM-EDX analysis. The alumina enriched fly ash was then loaded with KF (10 wt%) and calcined at three different temperatures 473 K, 673 K and 873 K. The amount of loaded KF was monitored by XRD, FTIR spectroscopy, SEM-EDX, TEM and Flame Atomic Absorption Spectrophotometer. The catalytic activities of the catalysts were tested in the Claisen-Schmidt condensation of benzaldehyde and 4-methoxybenzaldehyde with 2′-hydroxyacetophenone to produce 2′-hydroxychalcone and 4-methoxy-2′-hydroxychalcone respectively. Higher conversion (83%) of benzaldehyde and (89%) of 4-methoxybenzaldehyde reveals that among these heterogeneous catalysts KF/Al2O3/fly ash673 is very active.

Determination of Lead Content in Red Colored Lipsticks from Mandalay Market by Flame Atomic Absorption Spectrophotometer

2018 ◽  
Vol 30 (3) ◽  
pp. 167-173
Keyword(s):  
Sampling Procedure ◽  
The Body ◽  
Lead Content ◽  
Social Psychological ◽  
Allowable Limit ◽  
Flame Atomic Absorption ◽  
Therapeutic Benefits ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Exposure Levels

Red colored lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because some lipsticks contain a considerable amount of heavy metal especially lead. Lead is being used in lipstick mainly for the pigments required to obtain needed colors. Lead accumulates in the body over time and lead-containing lipstick applied several times a day, every day, combined with lead in water and other sources, could add up to significant exposure levels. Therefore, this study was aimed to determine lead content in red colored lipsticks from market. This study was laboratorybased, analytical study by using 25 lipstick samples. Red colored lipsticks were bought from Mandalay Market by random sampling procedure and they were completely coded to avoid the bias. Then, lead content in coded samples was determined by Flame AAS according to International Conference on Harmonization (ICH) guideline. Lead contents of 88% of the lipsticks samples were more than specified limit (20 ppm) of Food and Drug Administration, United States. All of them, lead content was highest in counterfeit lipsticks group. Among the tested lipstick samples, lipstick with lowest lead content was LE-RL 01 (15.74 ppm) and the lipstick with highest lead content was CF-RL 01(60.09 ppm). In conclusion, lead contents of red colored lipsticks (22 out of 25) from market samples were higher than allowable limit (20 ppm).

scholarly journals Characterization of Toxic Metals in Tobacco, Tobacco Smoke, and Cigarette Ash from Selected Imported and Local Brands in Pakistan

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Huma Ajab ◽  
Asim Yaqub ◽  
Salman Akbar Malik ◽  
Muhammad Junaid ◽  
Sadia Yasmeen ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Toxic Metals ◽  
The Body ◽  
Metal Extraction ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Cigarette Ash ◽  
Tobacco Smoke Condensate ◽  
Significant Concentration

In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.

scholarly journals Assessing the Effect of Weak and Strong Acids as Electrolytes in the Removal of Cesium by Soil Electrokinetic Remediation

2020 ◽  
Vol 21 (1) ◽  
pp. 118
Author(s):  
Rudy Syah Putra ◽  
Alfi Ihda Amalia ◽  
Naila Zahrotul Jannah
Keyword(s):  
Acetic Acid ◽  
Contaminated Soil ◽  
Physicochemical Characteristics ◽  
Ph Control ◽  
Electrokinetic Remediation ◽  
Current Profile ◽  
Data Logger ◽  
Soil C ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer

The removal of cesium from artificially contaminated soil using electrokinetic remediation with nitric and acetic acid as electrolytes had been evaluated. In this study, uncontaminated soil was taken from four different sampling points (i.e., A, B, C, and D) in Kotagede, Yogyakarta, Indonesia. All samples were prepared as cesium contaminated soil (100 mg CsCl/kg soil), which have similar physicochemical characteristics with Fukushima soil, Japan. The electrokinetic remediation (EKR) was conducted using a graphite electrode in a constant voltage of 1.0 Vcm–1 for 7 days without electrolyte pH control, with 1.0 M nitric and acetic acid as electrolytes. The current profile during the EKR was recorded by a data logger for every 10 min. The remaining cesium in the soil was measured by a flame atomic absorption spectrophotometer at a wavelength of 852.1 nm. The results showed that the type of acid used in the experiments affected the removal of cesium. The highest cesium removal was achieved when nitric acid was used in the experiment and then followed by acetic acid. For all acids, the removal ability of cesium from soil was in the following order: soil C > soil A > soil D > soil B.

scholarly journals Removal of Phenol from Aqueous Solution by Adsorption on to Coal Fly Ash

1996 ◽  
Vol 13 (6) ◽  
pp. 527-536 ◽  
Author(s):  
L.J. Alemany ◽  
M.C. Jiménez ◽  
M.A. Larrubia ◽  
F. Delgado ◽  
J.M. Blasco
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Removal Efficiency ◽  
Ph Value ◽  
Coal Fly Ash ◽  
Solid Wastes ◽  
Power Stations ◽  
Different Temperatures ◽  
Coal Power ◽  
Coal Power Stations

The present work examines the possible use of fly ash, a byproduct of coal power stations, as a means of removing phenol from water, or equivalently, of restricting its movement in solid wastes or soil. Equilibrium experiments were performed to evaluate the removal efficiency of fly ash. The adsorption experiments were undertaken using fly ash treated at three different pH levels and with three different temperatures. The results indicate that although phenol can be removed from water, this depends markedly on the temperature and pH value of the treatment solution employed.

Transesterification of Jatropha Oil to Biodiesel by Using Catalyst Containing Ca(C3H7O3)2 as a Solid Base Catalyst

2013 ◽  
Vol 666 ◽  
pp. 93-102 ◽  
Author(s):  
Chang Jun Li ◽  
Zhi Wei Huang ◽  
Yu Jie He ◽  
Dong Zhou ◽  
Cheng Du ◽  
...  
Keyword(s):  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Solid Base ◽  
Jatropha Oil ◽  
Direct Precipitation ◽  
Acid Methyl ◽  
Direct Precipitation Method ◽  
C Nmr

An direct precipitation method of Calcium glyceroxide Ca(C3H7O3)2 was proposed. The prepared Ca(C3H7O3)2 was effective in transesterification of Jatropha oil into fatty acid methyl esters (FAME). The Ca(C3H7O3)2 catalysts were characterized by using XRD, solid state 13C-NMR, FTIR, and Hammett indicator. The influence of various reaction variables on the conversion was investigated. Under a condition of methanol/oil molar ratio of 9:1, a catalyst amount of 4 wt %, reaction time of 1.5 h, and reaction temperature of 65 °C, over 95% of biodiesel yield was obtained.

Chemical Alumina Preparation by Using High Alumina Content Fly Ash

2017 ◽  
pp. 115-120 ◽  
Author(s):  
Guozhi Lv ◽  
Ting-an Zhang ◽  
Weiguang Zhang ◽  
Xiaofeng Zhu ◽  
Yan Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Alumina Content ◽  
High Alumina ◽  
High Alumina Content

Optimized atomic absorption spectrophotometry of calcium in erythrocytes.

1987 ◽  
Vol 33 (11) ◽  
pp. 2004-2007 ◽  
Author(s):  
S Nomoto ◽  
S Shoji
Keyword(s):  
Hydrochloric Acid ◽  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Graphite Tube ◽  
Optimum Conditions ◽  
Absorption Spectrophotometry ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
The Mean ◽  
Mean Concentration

Abstract We sought to establish optimum conditions for measuring calcium in erythrocytes by atomic absorption spectrophotometry. The conditions we selected are as follows. Wash one volume of fresh heparin-treated packed cells once with 30 volumes of isotonic buffered saline (pH 7.4) at a temperature somewhat exceeding 25 degrees C. Dilute the washed packed cells 10-fold with 12 mmol/L hydrochloric acid, and analyze the supernate for calcium. Measure the hematocrit of the washed packed cells, then analyze an aliquot of them for calcium, using a computer-readout type of flame or a non-flame atomic absorption spectrophotometer equipped with a pyrocoated graphite tube. The temperature program is 1000 degrees C for ashing [corrected] and 1800 degrees C for the atomizing cycle. Intraday and day-to-day reproducibility of the assay was 6.55% and 8.19%, respectively, at the mean concentration of calcium in the erythrocytes of healthy adults, which is 4.30 mumol/L.

scholarly journals Effect of Annealing on the ZnS Nanocrystals Prepared by Chemical Precipitation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nadana Shanmugam ◽  
Shanmugam Cholan ◽  
Natesan Kannadasan ◽  
Kannadasan Sathishkumar ◽  
G. Viruthagiri
Keyword(s):  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Atomic Force ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Uv Visible ◽  
Dta Curves

Nanocrystals of ZnS have been synthesized through simple chemical precipitation method using thiourea as sulphur source. The synthesized products were annealed at different temperatures in the range of 200–800∘C. The as-synthesized and annealed samples were characterized by X-ray diffraction (XRD), UV-Visible absorption (UV-Vis), and room temperature photoluminescence (PL) measurements. The morphological features of ZnS annealed at 200 and 500∘C were studied by atomic force microscope (AFM) and transmission electron microscope (TEM) techniques. The phase transformation of ZnS and formation of ZnO were confirmed by thermogravimetric (TG) and differential thermal analysis (DTA) curves.

scholarly journals Long-term hydrophilization of polydimethylsiloxane (PDMS) for capillary filling microfluidic chips

2019 ◽  
Vol 24 (1) ◽  
Author(s):  
Farzin Jahangiri ◽  
Tuuli Hakala ◽  
Ville Jokinen
Keyword(s):  
Cold Storage ◽  
Storage Temperature ◽  
Microfluidic Channel ◽  
Vibration Band ◽  
Microfluidic Chips ◽  
Thermally Activated ◽  
Capillary Filling ◽  
Different Temperatures ◽  
Long Term Preservation

AbstractWe present a simple and facile method for long-term preservation of hydrophilicity of oxygen plasma-hydrophilized poly (dimethylsiloxane) (PDMS) by cold storage. We show that storage under temperature of − 80 °C can maintain superhydrophilicity of plasma-exposed PDMS for at least 100 days. Storage at − 15 °C and at 22 °C room temperature (RT) is shown to exhibit, respectively, about half and full recovery of the original hydrophobicity after 100 days in storage. Furthermore, we investigated the implications of the cold storage for microfluidic applications, the capillary filling rate and the ability of the flow to bypass geometrical obstacles in a microfluidic channel. It is shown that the preservation of capillary filling properties of microchannels is in close agreement with the contact angle (CA) measurements and that the colder the storage temperature, the better the capillary filling capability of the channels is preserved. We ascribe the significantly reduced recovery rate to reduced thermally activated relaxation phenomena such as diminished diffusion of low molecular weight species (LMW) in the polymer matrix at colder temperatures. This is supported by ATR-FTIR measurements of the OH vibration band over time for samples stored at different temperatures.

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