scholarly journals Feasibility of Using an Electrolysis Cell for Quantification of the Electrolytic Products of Water from Gravimetric Measurement

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Samuel Melaku ◽  
Zewdu Gebeyehu ◽  
Rajeev B. Dabke
Keyword(s):  
Color Change ◽  
Cell Mass ◽  
Gravimetric Method ◽  
Constant Current ◽  
Electrolysis Cell ◽  
Gravimetric Measurement ◽  
Excess Amount ◽  
Coulometric Method ◽  
Potassium Hydrogen ◽  
Better Than

A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO3 was added to the anode compartment electrolyte. During electrolysis, cathode and anode compartments produced OH−(aq) and H+(aq) ions, respectively. Electrolytically produced OH−(aq) neutralized the KHP, and the completion of this neutralization was detected by a visual indicator color change. Electrolytically produced H+(aq) reacted with HCO3−(aq) liberating CO2(g) from the anode compartment. Concurrent liberation of H2(g) and O2(g) at the cathode and anode, respectively, resulted in a decrease in the mass of the cell. Mass of the electrolysis cell was monitored. Liberation of CO2(g) resulted in a pronounced effect of a decrease in mass. Experimentally determined decrease in mass (53.7 g/Faraday) agreed with that predicted from Faraday’s laws of electrolysis (53.0 g/Faraday). The efficacy of the cell was tested to quantify the acid content in household vinegar samples. Accurate results were obtained for vinegar analysis with a precision better than 5% in most cases. The cell offers the advantages of coulometric method and additionally simplifies the circuitry by eliminating the use of a constant current power source or a coulometer.

EFFECT OF ETCHING TIME ON OPTICAL AND MORPHOLOGICAL FEATURES OF N-TYPE POROUS SILICON PREPARED BY PHOTO-ELECTROCHEMICAL METHOD

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Asad A. Thahe ◽  
Noriah Bidin ◽  
Mohammed A. Al-Azawi ◽  
Naser M. Ahmed
Keyword(s):  
Porous Silicon ◽  
Gravimetric Method ◽  
Constant Current ◽  
Etching Time ◽  
Absorption Data ◽  
Time Duration ◽  
Constant Current Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structure Properties

Achieving efficient visible photoluminescence from porous-silicon (PSi) is demanding for optoelectronic and solar cells applications. Improving the absorption and emission features of PSi is challenging. Photo-electro-chemical etching assisted formation of PSi layers on n-type (111) silicon (Si) wafers is reported. Samples are prepared at constant current density (~30 mA/cm2) under varying etching times of 10, 15, 20, 25, and 30 min. The influence of etching time duration on the growth morphology and spectral properties are inspected. Room temperature photoluminescence (PL) measurement is performed to determine the optical properties of as-synthesized samples. Sample morphologies are imaged via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The thickness and porosity of the prepared samples are estimated using the gravimetric method. The emission and absorption data is further used to determine the samples band gap and electronic structure properties. Results and analyzed, interpreted with different mechanisms and compared.  

BRIGHT LUMINESCENCE OF FIRE RETARDANT ALUMINUM HYDROXIDE-SILICA SPHERE COMPOSITE

2018 ◽  
Vol 25 (06) ◽  
pp. 1850113
Author(s):  
HA-SUNG KONG ◽  
BYOUNG-JU KIM ◽  
KWANG-SUN KANG
Keyword(s):  
Aluminum Hydroxide ◽  
Color Change ◽  
Fire Retardant ◽  
Excitation Wavelength ◽  
Silica Spheres ◽  
Fire Retardancy ◽  
Characteristic Absorption ◽  
Excess Amount ◽  
Mg Addition ◽  
Bright Luminescence

Bright luminescence was achieved with excess amount of aluminum hydroxide with silica spheres. Various amounts of aluminum hydroxide were attached to silica spheres to improve the performance of fire retardancy. Although silica spheres attached with 60[Formula: see text]wt.% of AlCl3 (AlOH-A) showed no color change and luminescent chromophores, silica spheres attached with 80[Formula: see text]wt.% of (AlOH-B) and 100% of (AlOH-C) of AlCl3 changed the color and produced luminescent chromophores. The solution colors became intense yellow and brown for AlOH-B and AlOH-C, respectively, after 15 days. The FTIR spectra showed the characteristic absorption peaks of Al–OH and Si–O–Al. The concentration dependent photoluminescence (PL) intensities were continuously increased until 242[Formula: see text]mg addition of the colored solution and then slightly decreased thereafter for both AlOH-B and AlOH-C. The PL peaks shifted toward red by increasing the excitation wavelength for both AlOH-B and AlOH-C. Large Stoke shifts, such as 73 and 68[Formula: see text]nm for AlOH-B and AlOH-C, respectively, were observed.

scholarly journals Printability of papers recycled from toner and inkjet-printed papers after deinking and recycling processes

2017 ◽  
Vol 16 (2) ◽  
pp. 76-82
Author(s):  
Arif Karademir ◽  
Cem Aydemir ◽  
Dogan Tutak ◽  
Raja Aravamuthan
Keyword(s):  
High Efficiency ◽  
Color Change ◽  
Paper Industry ◽  
Optical Quality ◽  
Recycled Paper ◽  
High Optical Quality ◽  
Contemporary World ◽  
Before And After ◽  
Better Than

Background: In our contemporary world, while part of the fibers used in the paper industry is obtained from primary fibers such as wood and agricultural plants, the rest is obtained from secondary fibers from waste papers. To manufacture paper with high optical quality from fibers of recycled waste papers, these papers require deinking and bleaching of fibers at desired levels. High efficiency in removal of ink from paper mass during recycling, and hence deinkability, are especially crucial for the optical and printability quality of the ultimate manufactured paper. Methods: In the present study, deinkability and printability performance of digitally printed paper with toner or inkjet ink were compared for the postrecycling product. To that end, opaque 80 g/m2 office paper was digitally printed under standard printing conditions with laser toner or inkjet ink; then these sheets of paper were deinked by a deinking process based on the INGEDE method 11 p. After the deinking operation, the optical properties of the obtained recycled handsheets were compared with unprinted (reference) paper. Then the recycled paper was printed on once again under the same conditions as before with inkjet and laser printers, to monitor and measure printing color change before and after recycling, and differences in color universe. Results: Recycling and printing performances of water-based inkjet and toner-based laser printed paper were obtained. The outcomes for laser-printed recycled paper were better than those for inkjet-printed recycled paper. Conclusions: Compared for luminosity Y, brightness, CIE a* and CIE b* values, paper recycled from laser-printed paper exhibited higher value than paper recycled from inkjet-printed paper.

scholarly journals Fabrication and Characterization of Porous Silicon Layer Prepared by Photo-Electrochemical Etching in CH3OH:HF Solution

2013 ◽  
Vol 8 ◽  
pp. 29-36 ◽  
Author(s):  
Hasan A. Hadi ◽  
Raid A. Ismail ◽  
Nadir F. Habubi
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Gravimetric Method ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Constant Current ◽  
Theoretical Relation ◽  
Fabrication And Characterization ◽  
A Current

Porous silicon (PS) has been fabricated by Photo-electrochemical etching. Porous silicon was anodized on n-type Si in light using a current density of 20 mA/cm2 for 10 min. The porous structure formation was confirmed using XRD and AFM studies. The root mean square (RMS) roughness of the Porous silicon layer is found to be around 47.5 nm and the ten point height was 317 nm. The average of pores diameter was 419.98nm, and the grain growth is columnar with a (211) preferred orientation. The grain size of the PS was estimated from the Scherer’s formula and found to be 73 nm. All the properties of the porous silicon layer, such as porosity and the thickness depend on the anodization parameters. The porosity (P) was approximately 77%. The thickness of the layer formed during an anodization in constant current was 3.54 nm in gravimetric method, while its value was 1.77 nm by using the theoretical relation.

scholarly journals EVLW and its Importance in Fluid Management

2021 ◽  
Author(s):  
Hakan Yılmaz ◽  
Baturay Kansu Kazbek ◽  
Perihan Ekmekçi
Keyword(s):  
Transpulmonary Thermodilution ◽  
Fluid Management ◽  
Gravimetric Method ◽  
Tissue Perfusion ◽  
Gravimetric Measurement ◽  
Lung Water ◽  
Hemodynamic Management ◽  
Surgical Costs ◽  
Widespread Acceptance ◽  
Lymphatic Fluid

Fluid management and optimization is one of the most frequently observed problems in anesthesiology and critical care. An ideal hemodynamic management increases oxygen supply to tissues, improves postoperative outcomes and decreases surgical costs. Extravascular lung water (EVLW) measurement has gained widespread acceptance in the early prediction and management of adverse effects caused by fluid treatment. The fundamental aim of acute circulatory failure treatment is to improve tissue perfusion and oxygenation while avoiding fluid overload. EVLW consists of extravascular interstitial, intracellular, alveolar and lymphatic fluid in the lungs and its normal values are 3-7 ml kg-1. Studies have reported that values above 10 ml kg-1 as a cut-off value points to pulmonary edema. Although the gold standard in EVLW measurement is the gravimetric method, lung ultrasound and transpulmonary thermodilution is more widely utilized since gravimetric measurement can only be performed post-mortem. EVLW measurement is expected to gain importance in the hemodynamic measurement of ALI/ARDS patients and future studies will benefit from focusing on EVLW based fluid therapy.

114 VITRIFICATION OF BOVINE EMBRYOS IN MEDIUM WITH POLYVINYL ALCOHOL REPLACING BSA

2006 ◽  
Vol 18 (2) ◽  
pp. 165
Author(s):  
D. J. Walker ◽  
G. E. Seidel Jr
Keyword(s):  
Ethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Survival Rates ◽  
Sodium Hyaluronate ◽  
Blastocyst Stage ◽  
Embryo Survival ◽  
Better Than

Embryos vitrified in medium supplemented with 4.25 μg/mL sodium hyaluronate (SH) and 0.1% polyvinyl alcohol (PVA) survived vitrification better than embryos vitrified in medium supplemented with 0.25% FAF-BSA (Walker and Seidel 2005 Reprod. Fert. Dev. 17, 153). The purpose of the present study was to determine if the small amount of SH was beneficial to in vitro survival and to examine the effects of different concentrations of PVA in vitrification solutions. Day 7 blastocysts (n = 360) were produced in vitro with semen from three bulls, two replicates each. Cryoprotectant solutions were prepared in a 2 × 3 factorial combination with two SH concentrations (0 or 4.25 μg/mL) and three PVA concentrations (0.05, 0.1%, or 0.2%). For vitrification, embryos were placed into chemically defined HEPES-buffered medium (HCDM-2) at room temperature (22–24°C) and then transferred to V1 (5 m ethylene glycol in HCDM-2) for 3 min. Next, embryos were placed in a 6 μL drop of V2 (7 m ethylene glycol, 0.5 m galactose, and 18% w/v Ficoll 70 in HCDM-2) for 45 s. During these 45 s, dilution medium (0.5 m galactose in HCDM-2) was aspirated into 0.25-mL straws, followed by the 6 μL drop of V2 plus embryos and a final short column of dilution medium. When 45 s had elapsed, the heat-sealed end of straw was dipped into liquid nitrogen to cover the embryo, and then the remainder of the straw was immersed slowly. Straws were thawed in air for 10 s and then in 37°C water for 20 s. Next, straws were shaken like a clinical thermometer four times to mix columns, and held in 37°C water for 10 min before embryos were expelled, rinsed and cultured in CDM-2 + 5% FCS. At 48 h, embryo survival (as determined by expansion of blastocysts), embryo quality (1 = excellent, 2 = fair, 3 = poor), inner cell mass (ICM) quality (1 = large and compact, 2 = clearly visible, 3 = not discernable) and blastocyst stage (5 = early, 6 = full, 7 = expanded, 8 = hatching, 9 = hatched) were evaluated and replicate averages were analyzed by ANOVA. Neither bull nor SH concentration nor PVA concentration significantly affected any response (P > 0.10). Averaged over PVA concentrations, vitrification of embryos in 0 μg/mL or 4.25 μg/mL SH resulted in similar survival rates (67% vs. 62%, respectively). When averaged over SH concentrations, 0.2% PVA had a numerically higher survival rate of blastocysts as compared to 0.1% or 0.05% (71% vs. 63% and 60%, respectively). The main effects of 0 μg/mL SH and 0.2% PVA also resulted in numerically higher, but nonsignificant improvements in quality score, ICM score and blastocyst stage as compared to the other doses of SH and PVA. Vitrification of Day 7 in vitro-produced bovine blastocysts in medium containing 0.2% PVA in the absence of SH resulted in a subclass mean of 80% embryo survival. Results of this experiment show no benefit of 4.25 μg/mL SH and that 0.2% PVA may be slightly better than 0.05% or 0.1% in terms of embryo survival. Therefore, our results indicate that 0.2% PVA can be used alone as an effective alternative to animal products in this vitrification procedure for in vitro-derived bovine blastocysts.

scholarly journals Artificial Neural Network for Healthy Chicken Meat Identification

2018 ◽  
Vol 7 (1) ◽  
pp. 63
Author(s):  
Fajar Yumono ◽  
Imam Much Ibnu Subroto ◽  
Sri Arttini Dwi Prasetyowati
Keyword(s):  
Neural Network ◽  
Texture Analysis ◽  
Experimental Approach ◽  
Color Change ◽  
Chicken Meat ◽  
Color Analysis ◽  
Canny Edge ◽  
The Right ◽  
Very High ◽  
Better Than

Indonesia is the country with the largest number of Muslims in the world. Every Muslim is taught to consume thoyyiban halal meat or healthy chicken because it is slaughtered in the right way and stored in a good way too. But the reality in the market of many chicken meat on the market can not meet that criteria. Identification of healthy chicken meat can be done with laboratory experiments, but that is not simple and takes time. This experiment offers a cheaper, faster approach, with very high accuracy. The experimental approach is based on color and texture analysis on 5 types of meat quality based on healthy value. Color analysis was performed using artificail neural network (ANN) while texture analysis used Canny edge detection. Experimental results show that the color histogram approach with ANN is better than the texture approach, ie 94% versus 66%. It can be concluded that the freshness of a chicken does not have much effect on the texture of the meat but it has an effect on the color change in the meat.

Incidences of Problematic Organisms on Petrifilm Aerobic Count Plates Used To Enumerate Selected Meat and Dairy Products

2005 ◽  
Vol 68 (7) ◽  
pp. 1506-1511 ◽  
Author(s):  
G. S. DAWKINS ◽  
J. B. HOLLINGSWORTH ◽  
M. A. E. HAMILTON
Keyword(s):  
Bacillus Subtilis ◽  
Incubation Period ◽  
Bacillus Licheniformis ◽  
Dairy Products ◽  
Color Change ◽  
Close Correlation ◽  
Large Numbers ◽  
Indicator Dye ◽  
Group D ◽  
Better Than

Petrifilm aerobic count plates are similar to or better than conventional pour plates. Petrifilm has its problems, however; some microorganisms can liquefy the Petrifilm gel and others do not produce the necessary color change with the indicator dye used. Petrifilm aerobic count plates were compared with the pour plates for determining the incidence and identification of problematic organisms in 329 meat and dairy products. Petrifilm plates produced higher mean counts with better repeatability than did pour plates. There was also close correlation between methods with coefficients of 0.97 to 1.0. Bacillus subtilis, Bacillus licheniformis, and a group D Streptococcus liquefied Petrifilm gels in 17.4% of the samples tested: dairy products accounted for 16.0%, and meats accounted for the remaining 1.4%. Liquefaction hindered enumeration in 3.2% of the Petrifilm plates used. Streptococcus viridans was not detectable on Petrifilm plates after the recommend incubation period, and this organism occurred in 0.3% of the Petrifilm plates used. These results indicate that Petrifilm plates would be unsuitable for samples with large numbers of these organisms. Knowledge of the contaminating flora may be an asset when utilizing Petrifilm aerobic count plates for the enumeration of microbes in food.

Adaptation to intermittent stress promotes maintenance of β-cell compensation: comparison with food restriction

2008 ◽  
Vol 295 (4) ◽  
pp. E947-E958 ◽  
Author(s):  
Holly E. Bates ◽  
Adam Sirek ◽  
Michael A. Kiraly ◽  
Jessica T. Y. Yue ◽  
Michael C. Riddell ◽  
...  
Keyword(s):  
Food Restriction ◽  
Cell Mass ◽  
Β Cells ◽  
Β Cell ◽  
Cell Hyperplasia ◽  
Cell Hypertrophy ◽  
Zdf Rats ◽  
Insulin Responses ◽  
Obese Male ◽  
Better Than

Intermittent restraint stress delays hyperglycemia in ZDF rats better than pair feeding. We hypothesized that intermittent stress would preserve β-cell mass through distinct mechanisms from food restriction. We studied temporal effects of intermittent stress on β-cell compensation during pre-, early, and late diabetes. Six-week-old obese male ZDF rats were restraint-stressed 1 h/day, 5 days/wk for 0, 3, 6, or 13 wk and compared with age-matched obese ZDF rats that had been food restricted for 13 wk, and 19-wk-old lean ZDF rats. Thirteen weeks of stress and food restriction lowered cumulative food intake 10–15%. Obese islets were fibrotic and disorganized and not improved by stress or food restriction. Obese pancreata had islet hyperplasia and showed evidence of neogenesis, but by 19 wk old β-cell mass was not increased, and islets had fewer β-cells that were hypertrophic. Both stress and food restriction partially preserved β-cell mass at 19 wk old via islet hypertrophy, whereas stress additionally lowered α-cell mass. Concomitant with maintenance of insulin responses to glucose, stress delayed the sixfold decline in β-cell proliferation and reduced β-cell hypertrophy, translating into 30% more β-cells per islet after 13 wk. In contrast, food restriction did not improve insulin responses or β-cell hyperplasia, exacerbated β-cell hypertrophy, and resulted in fewer β-cells and greater α-cell mass than with stress. Thus, preservation of β-cell mass with adaptation to intermittent stress is related to β-cell hyperplasia, maintenance of insulin responses to glucose, and reductions in α-cell mass that do not occur with food restriction.

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