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Wyświetlanie 1-8 z 8
Tytuł:
Efficiency evaluation of Luffa cylindrica and Mucuna sloanei seeds in dye removal: A news approach
Autorzy:
Nnaji, P. C.
Okoye, C. C.
Umeuzuegbu, J. U.
Powiązania:
https://bibliotekanauki.pl/articles/1031647.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Luffa cylindrica
Mucuna sloanei
coag-flocculation rate constant
critical coag-flocculation rate constant
dye-based wastewater
Opis:
The use of Luffa cylindrica (LC) and Mucuna sloanei (MS) seeds as coagulants in the removal of dye by coag-flocculation was evaluated using a new approach. The approach uses the coag-flocculation rate constant K11, calculated using experimental data obtained while using LC and MS as coagulants in coag-flocculation process as a valid indicator to determine the optimum condition. The research also applied criterion for critical coag-flocculation rate constant Kc to satisfy World Health Organization’s minimum allowable level of suspended substance for wastewater discharge. In the criterion K11 ≥ Kc indicates better performance. The results indicated that K11 of 0.00214 L/mg·min for LC and 0.00208 L/mg·min for MS surpassed 0.00016 L/mg·min Kc value. This was observed for LC and MS at pH 2, but 1400 mg/L and 1200 mg/L, respectively. From the above, in accordance with the WHO guideline, the dosage of both coagulants meets the requirement. The solution pH could not meet the standard. Nonetheless, MS satisfied the requirement at pH 6, for dosage and pH. These results correspond to what was obtained experimentally. Therefore, in coag-flocculation kinetic modeling, this novel approach can be considered to track the efficiency of these sensitive factors in water treatment plants to meet the effluent quality requirements.
Źródło:
World Scientific News; 2020, 146; 184-201
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shifted Chebyshev-Lanczos polynomials
Autorzy:
Caltenco, J. H.
López-Bonilla, J.
Peña-Rivero, R.
Powiązania:
https://bibliotekanauki.pl/articles/1177824.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Feigenbaum constant
Modified Lanczos polynomials
Pascal triangle
Opis:
We show an algorithm for to express in terms of the modified Chebyshev-Lanczos polynomials , which is important to reduce the degree of a polynomial in the interval [0, 1]. Besides, with the use of into logistic map we obtain a simple geometric interpretation of the Feigenbaum´s universal constant.
Źródło:
World Scientific News; 2018, 99; 222-226
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-adiabatic universe and the redshift
Autorzy:
Gupta, Rajendra P.
Powiązania:
https://bibliotekanauki.pl/articles/1163142.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Cosmic microwave background radiation
Cosmological constant
Cosmology theory
Distance scale
Distances and redshifts
Galaxies
General relativity
Hubble constant
Supernovae
Opis:
We have relaxed the constraint of adiabatic universe used in most cosmological models and shown that the new approach provides a better fit to the supernovae Ia redshift data with a single parameter, the Hubble constant, than the standard ΛCDM model with two parameters, the Hubble constant and the cosmological constant. The new approach, developed within the confines of the cosmological principle, yields the Hubble constant value 69.01 (±0.53) km s-1 Mpc-1. The cosmological constant may thus be considered as a manifestation of a non-adiabatic universe that is treated as an adiabatic universe.
Źródło:
World Scientific News; 2018, 110; 210-218
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chenodeoxycholic acid: A Physicochemical study
Autorzy:
Baluja, Shipra
Bhesaniya, Kapil
Powiązania:
https://bibliotekanauki.pl/articles/1193963.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Chenodeoxycholic acid
Dissociation constant
acoustical parameters
thermal analysis
Opis:
Some physicochemical properties such as dissociation constant, acoustical parameters and thermal studies of acid are studied in methanol and 1,4-dioxane at 298.15 K. The dissociation constant of Chenodeoxycholic acid is evaluated in binary mixtures (of methanol / 1,4-dioxane + water) by two methods; half-integral and average methods. The acoustical properties have been evaluated from experimental data of density, viscosity and ultrasonic velocity. It is observed that in both the solvents, strong solute-solvent interactions exist. Thermal degradation of Chenodeoxycholic acid is found to be a single step process.
Źródło:
World Scientific News; 2015, 18; 115-127
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Inverse Reaction Cross Sections for Unit Rate Cost Model for Pricing Weld Mesh Reinforcement in Construction Projects
Autorzy:
Samuel, Egwunatum I.
Akpokodje, I. O.
Powiązania:
https://bibliotekanauki.pl/articles/1193018.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Aggregation
Cost model
Estimate
Labour output constant
Time and motion study
Unit rate
Opis:
The subsisting methods of unit rate pricing in the construction industry are either determinate on immediate use basis (analytical pricing) or predictive (cost modeling). The literature cited in this paper showed that cost models used in the industry are spurious. Most of the models attempts to respond to whole building cost from inception to completion with a single formula. This paper argues that on the basis of the units of measurement of the various building elements, a holistic cost model for pricing a complete building cost is a near impossibility. Rather as a negation cost model on the basis of each work item is idealized. Accordingly, this paper responded by generating a unit rate cost model for weld mesh reinforcement. This was done by abstracting and decomposing the relevant cost data and using productivity study by time and motion to determine the various outputs for materials and labour. These were subsequently factored to the cost data to derive the unit rate cost. The paper concludes that the model enjoys flexibility of further mathematical treatment should any of the variable be constrained and recommends that other work items should be modeled if the cost of a project must be known and this model should be used to justify contractor’s tender for weld mesh reinforcement bid.
Źródło:
World Scientific News; 2016, 28; 84-100
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and modelling investigation of caesium adsorption on soil samples around DAE facility, India
Autorzy:
Maity, Sukanta
Sandeep, Police
Sahu, Sanjay Kumar
Kumar, A. Vinod
Powiązania:
https://bibliotekanauki.pl/articles/1030685.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CEC
Laboratory batch method
caesium
chemical parameters
distribution coefficient (Kd)
equilibration time
isotherm
rate constant
Opis:
The kinetics and thermodynamics behind the sorption process of Cs (Caesium) on the soil are important to understand as these studies give information about the mobility of Cs in the environment. In the present study, sorption kinetics and the parameters influencing sorption (viz. time of contact, competing ions, temperature, solution pH and Cs concentration) were studied on the soil samples collected from Tarapur area. Site-specific distribution coefficient (Kd) of Cs was also estimated in soil samples collected from different locations across Tarapur, India using laboratory batch method. The effect of soil parameters (viz. pH, cation exchange capacity, organic matter and CaCO3) on Kd values of Cs was also investigated. The data of Cs adsorption on the soil is well fitted with the pseudo-second-order kinetic equation with the correlation coefficient (R2) value of 0.99. The rate constant (k2) of Cs adsorption (at 25 ºC) on collected soil samples was found to be 3.33×105 g µg-1 min-1. In the present study, Cs adsorption data were well fitted with Freundlich and Dubinin–Radushkevich (D–R) isotherm models. The change of enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) were estimated for the Cs adsorption on soil samples. Results showed that the adsorption process was exothermic (ΔH = -3.69 J mol−1) and favoured at a lower temperature. The calculated ΔG value (< 0) indicates that the Cs sorption on the soil is a spontaneous process. The Kd values were found to the range of 58 ± 2 to 275 ± 10 kg-1. The parametric study indicated CEC to have a stronger influence as compared to pH, OM and CaCO3 in the soil samples.
Źródło:
World Scientific News; 2020, 139, 2; 201-220
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, characterization, biological activity of Schiff bases derived from 2-bromo-4-methyl aniline and its potentiometric studies with Cu(II), Co(II) and Ni(II) ions
Autorzy:
Upadhyay, Surbhi V.
Zala, Raksha V.
Bhatt, Keyur D.
Powiązania:
https://bibliotekanauki.pl/articles/1030767.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
2-bromo-4-methyl aniline
Antimicrobial activity
Irving-Rossotti
Potentiometric studies
Schiff base
Stability constant
Opis:
Schiff bases namely, 2-bromo-4-methyl-N-(2-nitrobenzylidene)aniline; 2-bromo-4-methyl-N-(2,4,5-trimethoxybenzylidene)aniline; 2-bromo-N-(4-methoxybenzylidene)-4-methylaniline and N-((1H-indol-3-yl)methylene-2-bromo-4-methylaniline have been synthesized and characterized by elemental analysis, FT-IR, Mass and 1H-NMR spectroscopy. Schiff bases have been screened for Antimicrobial activity against bacteria and fungi by using MIC determination. Binary complexes of Co(II), Ni(II) and Cu(II) with Schiff bases in solution have been studied potentiometrically in 60:40 % (V/V) 1,4-dioxane-water system at constant temperature 27 ±0.5 ºC and at an ionic strength of 0.1 M KNO3. The order of stability constant of formed binary complexes in solution was examined.
Źródło:
World Scientific News; 2020, 145; 1-15
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infrared and 13C NMR Spectral Correlation Analysis of Some Substituted Oxazepin Based Ketone and Thione Derivatives with Hammett Constant
Autorzy:
Sathiyamoorthi, K.
Kamalakkannan, D.
Suresh, R.
Sakthinathan, S. P.
Arulkumaran, R.
Sundararajan, R.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1193044.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Oxazepins
IR
13C NMR
Hammett constant
F and R parameter
Single and multi-regression analysis
Opis:
Single and multi-regression analysis was applied for the corrosion study of transmission of substituent effects on IR carbonyl stretching frequencies and 13C chemical shifts of some substituted oxazepin compounds. The substituent effects were estimated on the basis of results of the statistical analysis. The differences among the obtained regression coefficients were discussed in terms of the relative importance of the field, inductive and resonance effects of substituent.
Źródło:
World Scientific News; 2016, 58; 48-64
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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