scholarly journals Tobacco Stalk Waste Biomass Holds Multilayer and Spontaneous Adsorption Capabilities for Reactive Black 5 Dye: Equilibrium Modelling and Error Function Analysis

Author(s):  
Jehanzeb Ali Shah ◽  
Cyrus Raza Mirza ◽  
Tayyab Ashfaq Butt ◽  
Walid Khalifa ◽  
Hatem Gasmi ◽  
...  
2017 ◽  
Vol 19 (1) ◽  
pp. 74-81 ◽  

<p>The composite media, Zeliac<sup>TM</sup> was developed with the initial aim to provide low cost adsorbent with promising adsorption capacity. This study was conducted to investigate the removal of UV absorbance at 254 nm (UV<sub>254</sub>) in Kerian river water using Zeliac<sup>TM</sup> as the media. Batch experiments study was carried out to determine the optimum removal of UV<sub>254</sub> by Zeliac<sup>TM</sup>. The experimental data were fitted to Langmuir and Freundlich isotherms to investigate the adsorption mechanism. The results from batch study exhibit that Zeliac<sup>TM</sup> is capable to remove 74.4% UV<sub>254</sub> at the dosage of 7g/100 ml. Linear isotherm analysis suggests that the best fitting linear line is Freundlich isotherm with R<sup>2</sup> values of 0.9294 indicating multilayer adsorption. Similarly, non-linear regression analysis reveals that the adsorption of UV<sub>254</sub> by Zeliac<sup>TM</sup> is attributed by physisorption. The non-linear Freundlich isotherm gives a better fit to the adsorption of UV<sub>254</sub> than Langmuir isotherm with R<sup>2</sup> values of 0.9488. The results are supported with low values of X<sup>2</sup>, ARE, HYBRID and MPSED from the error function analysis.&nbsp; Additionally, it is noted that the linear analysis overestimates the constant parameters’ values for Freundlich isotherm, which cause larger errors as estimated by the error function analysis. Hence, non-linear analysis is more appropriate in explaining the batch experiment data.</p>


2010 ◽  
Vol 649 ◽  
pp. 23-28
Author(s):  
Viktor Bánhidi ◽  
Tamas J. Szabo

In the frame of an international cooperation a 4 year long project was executed to determine thermal conductivity in metallic melts. During the project, the University of Miskolc designed and developed unique apparatus which was capable to perform measurements under microgravity conditions. The experiments were carried out at the Drop Tower „Bremen” where the conditions of reduced gravity could be provided for 4.7 s and a gravity level of 10-5g was achieved. The registered temperature distribution data of the examined melts always show a clear difference between the experiments measured in the normal and in the low gravity environment. During the evaluation of the datasets it was proven, that the well known canonical evaluations could not be used with high reliability for all the measurements, for all the materials and for all the geometry used. Besides of the understanding of the underlying physics and evaluating the measured data, the Crank-Nicolson method and error function analysis were used at the beginning, some numerical analyses were also initiated to simulate the system in FEM (Marc). The results showed acceptable results, but also pointed out a need for further study, so a detailed numerical analysis on a specialized FVM (Fluent) system was started. The code used for the numerical simulation (Fluent) was able to handle the heat conductivity, the liquid flow, the complex material parameters changes and the used geometries as well. With this technique, from the data of the drop experiments, the pure - free from the effect of the liquid flow - thermal conductivity could be separated. The results show that after these simulations, using different conditions (temperature, gravity level, etc.) for one material the same thermal conductivity value could be determined, within acceptable tolerance.


2020 ◽  
pp. 101-107
Author(s):  
Francis M. Maingi ◽  
Harun M. Mbuvi

Abstract: The Molo region of Kenya has experienced decreased potato acreage yields over the years. This has impacted negatively economic endeavors and food security of the region and Kenya at large. A preliminary study on the physical-chemical characterization of the soils indicated that they were deficient in the amount of available potassium. This finding was very important because the majority of the farmers in the region replenish phosphorous and nitrogen but not potassium. Subsequently, the present study was undertaken to determine the effect of replenishing selected farm soils with various potassium levels on the growth and productivity of ‘Shangi’ a variety grown in Molo Sub-county and ultimately determine the soil optimum potassium dose requirement. A field experiment was conducted with seven model-based K fertilizer treatments (0, 33.3, 41.5, 55.3, 133.3, 200 and 266.7 kg K2O/ha) and three replications in Randomized Complete Block Design (RCBD). The potassium sorption study was conducted using soil samples as adsorbent while varying the K+ concentration in solution. The data obtained were treated using both linearized and non-linearized Freundlich adsorption isotherms. The optimum potassium fertilizer rate was evaluated using yield response models (Quadratic, linear-plateau, quadratic-plateau, and square root). The results of the study showed that the increase in soil potassium levels led to a significant increase in growth and yield parameters. Aerial stem number, leaf number per plant, and plant height recorded increase with an increase in K levels. The sorption data were found to fit best in linearized Freundlich isotherm based on correlation coefficient values (R2) and error function analysis. The potassium buffering capacity ranged from 13.667-46.068 with a mean of 33.6 ± 17.4mg/Kg. The quadratic model fitted the data better than other models with R2 (0.9559) and SSE (18.237). K2O fertilizer application at 200 Kg/ha maximized the potato tuber yield to 30.111 Ton/ha. The result showed clearly that there is a need to adopt the use of potassium-based fertilizer according to soil requirements in this region to realize good tuber yield.


2021 ◽  
Vol 11 (16) ◽  
pp. 7432
Author(s):  
Kowit Suwannahong ◽  
Surachai Wongcharee ◽  
Torpong Kreetachart ◽  
Chadrudee Sirilamduan ◽  
Javier Rioyo ◽  
...  

The sorption of basic dyes onto magnetic nanosorbent is commonly used as a novel material to combat powdered activated carbon, which is difficult to handle and separate during water and wastewater treatment. This adsorption method is commonly implemented in water and wastewater treatment due to its low cost and high performance. To explore the feasibility of adsorption, six different nonlinear isotherm models were applied and introduced to evaluate the performance and adsorption mechanisms via Microsoft Excel, and they were then compared to those of MATLAB and OriginPro. The Langmuir best provided the sorption of methylene blue adsorbed for a two-parameter isotherm model. The three-parameter model Toth gave a goodness of fit indicating a heterogeneous sorbent surface. Error function analysis found that the Residual Sum of Squares Error, Chi-square, Coefficient of determination, Average Relative Error, Hybrid Fractional Error Function, Marquardt’s Percent Standard Deviation and Root Mean Square Error provided the best overall results. In comparison, it could be concluded that six isotherm models showed the confidence interval that is simply the best fit at all experimental data points provided by the three software tools. All error function results indicated that the Microsoft Excel Solver function spreadsheet method satisfied all the statistic measures to predict the real variance of the probability of experimental data for all six isotherm models of adsorption of basic dye removal. One added benefit of this Microsoft Excel software tool is the built-in function associated with the desired type of application, which designates the desired type of error/statistical functions not mentioned in this research to the adsorbent materials used.


2019 ◽  
Vol 28 (4) ◽  
pp. 834-842
Author(s):  
Harini Vasudevan ◽  
Hari Prakash Palaniswamy ◽  
Ramaswamy Balakrishnan

Purpose The main purpose of the study is to explore the auditory selective attention abilities (using event-related potentials) and the neuronal oscillatory activity in the default mode network sites (using electroencephalogram [EEG]) in individuals with tinnitus. Method Auditory selective attention was measured using P300, and the resting state EEG was assessed using the default mode function analysis. Ten individuals with continuous and bothersome tinnitus along with 10 age- and gender-matched control participants underwent event-related potential testing and 5 min of EEG recording (at wakeful rest). Results Individuals with tinnitus were observed to have larger N1 and P3 amplitudes along with prolonged P3 latency. The default mode function analysis revealed no significant oscillatory differences between the groups. Conclusion The current study shows changes in both the early sensory and late cognitive components of auditory processing. The change in the P3 component is suggestive of selective auditory attention deficit, and the sensory component (N1) suggests an altered bottom-up processing in individuals with tinnitus.


Sign in / Sign up

Export Citation Format

Share Document