Describing second-order spatiotemporal couplings in ultrashort pulses using correlation coefficient

2009 ◽  
Vol 26 (10) ◽  
pp. 1869 ◽  
Author(s):  
Shuguang Zeng ◽  
Youquan Dan ◽  
Bin Zhang
Keyword(s):  
Correlation Coefficient ◽  
Ultrashort Pulses ◽  
Second Order

scholarly journals OPTIMIZATION OF LEVOFLOXACIN REMOVAL FROM AQUEOUS SOLUTION USING ELECTROCOAGULATION PROCESS BY RESPONSE SURFACE METHODOLOGY

2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha
Keyword(s):  
Aqueous Solution ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Correlation Coefficient ◽  
Iron Hydroxide ◽  
Second Order ◽  
Experimental Results ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
Good Agreement

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.

Biopolymeric Adsorbent for the Removal of Methylene Blue: Characterizations, Equilibrium Isotherms and Kinetic Studies

2015 ◽  
Vol 1125 ◽  
pp. 281-285
Author(s):  
Siti Aishah Muhmed ◽  
Mohd Ghazali Mohd Nawawi
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Correlation Coefficient ◽  
Kinetic Studies ◽  
Second Order ◽  
Equilibrium Isotherms ◽  
Chi Square ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.

On the second order characterization of ultrashort pulses

1999 ◽  
Vol 46 (15) ◽  
pp. 2069-2077
Author(s):  
Roberto Ortega-Martínez ◽  
Carlos J. Román-Moreno ◽  
Dmitrii Kouznetsov
Keyword(s):  
Ultrashort Pulses ◽  
Second Order

scholarly journals On Second Order Slope Rotatable Designs under Intra-class Correlated Structure of Errors Using a Pair of Dissimilar Incomplete Block Designs

2020 ◽  
pp. 1-12
Author(s):  
Sulochana Beeraka ◽  
Re. Victor Babu Bejjam
Keyword(s):  
Correlation Coefficient ◽  
Second Order ◽  
Block Designs ◽  
Incomplete Block ◽  
Intra Class Correlation ◽  
Error Structure ◽  
Balanced Incomplete Block Designs ◽  
Balanced Incomplete Block ◽  
Block Sizes ◽  
Intra Class Correlation Coefficient

In this paper, a study of second order slope rotatable designs under intra-class correlation error structure using two suitably chosen dissimilar incomplete block designs like balanced incomplete block designs and symmetrical unequal block arrangements with two unequal block sizes are suggested. Further, we study the variance of the estimated slopes for different values of the intra-class correlation coefficient (ρ) and the distance from the centre (d) for v factors are suggested. Some illustrative examples are also suggested.

scholarly journals Oyster Shell Waste (Crassostrea Gigas) as A Cheap Adsorbent for Adsorption Of Methylene Blue Dyes: Equilibrium and Kinetics Studies

2021 ◽  
Vol 1 (4) ◽  
pp. 95-102
Author(s):  
Muhammad Muhammad ◽  
Meriatna Meriatna ◽  
Nia Afriani ◽  
Rizka Mulyawan
Keyword(s):  
Methylene Blue ◽  
Correlation Coefficient ◽  
Crassostrea Gigas ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Oyster Shell ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Shell Powder

In this study, Oyster (Crassostrea gigas) shell powder which contains calcium carbonate (CaCO3) was converted into calcium oxide (CaO). The Oyster shell powder that had been activated was utilized for the adsorption of the methylene blue (MB) dyeing material, which is one of waste water concerns. Oyster shells were crushed and sieved into 100 mesh sized powder and then calcinated at a temperature of 600℃ and 800℃ both for 4 hours period. To determine the adsorption equilibrium, methylene blue (MB) solution was used with varying concentration from 10 to 50 mg/L in which the adsorbent weighing 3 g was put into a conical flash and shaken until the adsorption equilibrium was reached. As for the adsorption kinetics, 250 mL MB solution was used with initial concentrations of 10, 20 and 30 mg/L, with an adsorbent weight of 3 g and a solution at pH 11 for each concentration. The evaluation of the experimental data from the adsorption process is well explained by the Freundlich equation, with the correlation coefficient value (R2) found to be 0.9999, where the value of the adsorption intensity (n) is close to unity; this shows that the adsorption is multilayer or in other words the adsorption energy is heterogeneous. The kinetics study also shows that pseudo second-order model is the most applicable to the adsorption process. From the pseudo-second-order model, with the correlation coefficient between 0.9984 - 0.9999 can explain that the methylene blue (MB) adsorption process is chemically based sorption or in other words termed as chemisorption.

scholarly journals Transformation of residual biomass into adsorbent materials: Applications to treatment of liquid effluents

2019 ◽  
Vol 9 (1) ◽  
pp. 1-11
Author(s):  
Samia Glissi ◽  
Meriem Tarbaoui ◽  
Laila Makouki ◽  
Khadija Legrouri ◽  
Hassan Hannache ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Phosphoric Acid ◽  
Correlation Coefficient ◽  
Chemical Activation ◽  
Second Order ◽  
Order Kinetic ◽  
Residual Biomass ◽  
Pseudo Second Order ◽  
The Impact ◽  
Adsorbent Materials

In this work, some adsorbent materials were prepared from residual biomass, which constitutes a real hazard for the environment and human health. So, in order to valorize this vegetal resource, a process of transformation was studied. The residual biomass was turned into adsorbent materials under the effect of chemical activation with phosphoric acid which allows the development of a large pore in the activated materials. The optimization of the conditions for the elaboration of our adsorbents was realized by experimental design by evaluating some parameters (percentage of phosphoric acid, temperature and time of activation) and their effects on the responses (capacity of adsorption of methylene blue, adsorbent yield), these parameters were selected after a screening study. The activation of our residual biomass was effected with 60% of phosphoric acid in 225°C while 115 min. The studied biomass was characterized by different physic-chemical methods (Differential Thermal Analysis /Thermogravimetric Analysis (DTA/TGA), Scanning Electron Microscopy (SEM), Raman and X-Ray Diffraction (XRD)); the results of characterization show the presence of the excellent textural and structural properties. The application of the best adsorbent in the removal of textile dyes (methylene blue) from aqueous solutions was studied. The impact of various parameters such as contact time, pH and concentration on the removal was evaluated by batch method. The adsorption isotherms were studied using Langmuir and Freundlich isotherm models. Langmuir isotherm provided the best fit to the equilibrium data with a correlation coefficient equal to 0.998. This result shows the presence of monolayer adsorption. The experiments demonstrated that the removal of methylene blue followed the pseudo-second-order kinetic model. The correlation coefficient is consistent and equal to unity, and the experimental qe value (44.17) was agreed with the calculated qe value (45.45) of pseudo-second-order then the value of pseudo-first-order which confirm a chemisorption process. The obtained results revealed that the elaborated material is an effective adsorbent for the removal of methylene blue.

Scandium adsorption from sulfuric-chloride solutions with activated carbons

2019 ◽  
pp. 49-55
Author(s):  
Wai Moe Aung ◽  
M. V. Marchenko ◽  
I. D. Troshkina
Keyword(s):  
Correlation Coefficient ◽  
Diffusion Model ◽  
Activated Carbons ◽  
Second Order ◽  
Model Description ◽  
Particle Diffusion ◽  
Diffusion Region ◽  
Chloride Solutions ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

The study covers scandium adsorption in batch conditions by VSK, DAS and PFT activated carbon grades (Russia) of different origin (сoconut shell, аnthracite, thermoset waste, respectively) from sulfuric acid-chloride solutions (pH = 2) simulating the composition of the underground leaching solutions of polymetallic ores. It was found that scandium adsorption by DAS and VSK carbons proceeds with the highest distribution coefficients (133 and 45.8 cm3/g, respectively). Isotherms of scandium adsorption with these carbons are linear and described by the Henry equation with constants 133 ± 21 and 46 ± 7 cm3/g, respectively. A limited solution volume method was used to obtain the integral kinetic curves of scandium adsorption. Their linearization according to the kinetic models of the pseudo-first, pseudo-second order, the Elovich model and the Weber–Morris intra-particle diffusion model indicates that the kinetics of scandium adsorption with VSK carbon having a higher correlation coefficient (0.999) is described using the pseudo-second order model. Description of the kinetic data obtained during the adsorption of scandium with DAS carbon showed that for all the models used the correlation coefficient is low (<0.939), while the highest value is observed when using the intra-particle diffusion model. It was suggested that the scandium adsorption process occurs in the mixed diffusion region. The possibility of scandium elution from VSK and DAS carbons with sodium carbonate solution (10 %) was studied in batch conditions, where the degree of scandium desorption in two stages of elution was 84.0 and 90.4 %, respectively.

scholarly journals SIV: Raise the Correlation of Second-Order Correlation Power Analysis to 1.00

2020 ◽  
Vol 10 (10) ◽  
pp. 3394
Author(s):  
Ju-Hwan Kim ◽  
Bo-Yeon Sim ◽  
Dong-Guk Han
Keyword(s):  
Power Consumption ◽  
Correlation Coefficient ◽  
Power Analysis ◽  
Second Order ◽  
Operational Characteristic ◽  
Secret Key ◽  
Cryptographic Algorithm ◽  
Correlation Power Analysis ◽  
Major Factors ◽  
Intermediate Value

The major factors that determine the performance of the second-order correlation power analysis (SOCPA) include the accuracy of the power model and the correlation between the hypothetical intermediate value and preprocessed power consumption. Because of the tradeoff between the accuracy and correlation, the correlation coefficient of the general SOCPA using 8-bit SubBytes output is only up to 0.35. Therefore, based on the operational characteristic of the cryptographic algorithm, we propose to find a special intermediate value, called sparse intermediate value (SIV). The SIV significantly improves the performance of the SOCPA because it accurately models the power consumption while the correlation coefficient is 1.00. Further, the experimental results on OpenSSL advanced encryption standard (AES) show that the SIV-based SOCPA can disclose the entire secret key with only about a quarter of the power trace required by the general SOCPA.

scholarly journals Batch Adsorption of Safranin Dye from an Aqueous Solution of Balanites aegyptiaca Seed Coats

2020 ◽  
pp. 48-54
Author(s):  
Buhari Magaji ◽  
Aisha U. Maigari ◽  
Usman A. Abubakar ◽  
Mukhtar M. Sani ◽  
Amina U. Maigari
Keyword(s):  
Aqueous Solution ◽  
Correlation Coefficient ◽  
Low Cost ◽  
Kinetic Studies ◽  
Second Order ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Seed Coats

This study was aimed at using Balanite aegyptiaca seed coats activated carbon (BAAC) as a potential adsorbent to remove safranin dye from aqueous solution. BAAC was prepared from Balanite aegyptiaca seed coats using a one-step procedure with 67.27% yield, 3.23% ash content, 695 m2/g surface area and 203 mg/g iodine number. The FTIR spectroscopy revealed O-H, N-H, C-H, C=C, C-O-H stretching vibrations. The influences of agitation time, initial dye concentration and adsorbent dose were studied in batch experiments at room temperature. The adsorptions were rapid at the first 15 minutes of agitation, with the uptake of 2.746 mg/kg. The adsorption equilibrium was achieved at 90 minutes of agitation. Kinetic studies showed good correlation coefficient for both pseudo-first order and pseudo-second-order kinetics model but fitted well into pseudo-second order kinetic model. The adsorption data fitted well into Langmuir isotherm with correlation coefficient (R2) very close to unity and Langmuir maximum adsorption constant, qm  1.00. Thus, the fitting into Langmuir indicates monolayer coverage on the adsorbents. The results showed that BAAC has the potential to be applied as alternative low-cost adsorbents in the remediation of dye contamination in wastewater.

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