A CONTRIBUTION TO THE QUALITATIVE GC ANALYSIS OF SOME NON-CHLORINATED XENOBIOTIC CHEMICALS IN WASTE WATERS

1994 ◽  
Vol 30 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Biljana D. Škrbic ◽  
Mirjana B. Vojinovic-Miloradov

Gas chromatographic unified retention indices of some chlorinated xenobiotic chemicals, as pollutants in waste waters, on OV-101 and SE-30 stationary phases are presented. These values agree well with the corresponding experimental values used in the statistical treaunent of the experimental data.

1983 ◽  
Vol 48 (11) ◽  
pp. 3270-3278 ◽  
Author(s):  
Marta Novrocíková ◽  
Jan Novrocík ◽  
Jan Vymětal

The Kováts retention indices (I) were determined by capillary gas-liquid chromatography on three stationary phases of different polarity, viz. OV-1, Ucon LB-550, and Reoplex 400, for 70 pyridine alkyl homologues present in coal tar. The increments for some alkyl groups were assessed, and the Kováts indices were predicted for 46 pyridine alkyl homologues and compared with the experimental data. The parameters of the linear dependences I(1) = kI(2) + q for pairs of stationary phases (1) and (2) were evaluated.


Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.


2018 ◽  
Vol 207 ◽  
pp. 02002
Author(s):  
Yaoke Wang ◽  
Meng Kou ◽  
Wei Ding ◽  
Huan Ma ◽  
Liangshan Xiong

When applying the non-parallel shear zone model to predict the cutting process parameters of carbon steel workpiece, it is found that there is a big error between the prediction results and the experimental values. And also, the former approach to obtain the relevant cutting parameters of the non-parallel shear zone model by applying coordinate transformation to the parallel shear zone model has a theoretical error – it erroneously regards the determinant (|J|) of the Jacobian matrix (J) in the coordinate transformation as a constant. The shape of the shear zone obtained when |J| is not constant is drew and it is found that the two boundaries of the shear zone are two slightly curved surfaces rather than two inclined planes. Also, the error between predicted values and experimental values of cutting force and cutting thrust is slightly smaller than that of constant |J|. A corrected model where |J| is a variable is proposed. Since the specific values of inclination of the shear zone (α, β), the thickness coefficient of the shear zone (as) and the constants related to the material (f0, p) are not given in the former work, a method to obtain the above-mentioned five constants by solving multivariable constrained optimization problem based on experimental data was also proposed; based on the obtained experimental data of AISI 1045 steel workpiece cutting force, cutting thrust, chip thickness, the results of five above-mentioned model constants are obtained. It is found that, compared with prediction from uncorrected model, the cutting force and cutting thrust of AISI 1045 steel predicted by the corrected model with the obtained constants has a better agreement with the experimental values obtained by Ivester.


2012 ◽  
Vol 212-213 ◽  
pp. 225-229
Author(s):  
Jie Gu ◽  
Dan Qing Ma ◽  
Wei Chen ◽  
Xin Qin ◽  
Xiao Li Wang

Based on the experimental data of sediment particle cloud during the settlement process in the water and combined with the existed sediment settling velocity formulae, a new formula for calculation of the settling velocity of sediment particle cloud is proposed by the introduction of the characteristic particle size of sediment particle cloud ( D' ). By using experimentally measured settling velocity values of sediment particle cloud to verify the settling velocity values of sediment particle cloud which calculated by using this new formula, the results show that the calculated settling velocity values using this new formula are closer to the experimental values.


2010 ◽  
Vol 46 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y. Du ◽  
J. Wang ◽  
Y.F. Ouyang ◽  
L.J. Zhang ◽  
Z.H. Yuan ◽  
...  

An integrated approach of experiment and theoretical computation to acquire enthalpies of formation for ternary compounds is described. The enthalpies of formation (DHf ) for Al71Fe19Si10 and Al31Mn6Ni2 are measured via a calorimeter. Miedema model, CALPHAD and first-principles method are employed to calculate DHf for the above compounds and several Al-based ternary compounds. It is found that first-principles generated data yield good agreements with experimental values and thus can be used as key 'experimental data', which are needed for CALPHAD approach.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 626
Author(s):  
Ireneusz Marzec ◽  
Jerzy Bobiński

Results of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity of the results with respect to the material parameters and the specimen geometry is investigated. Three different softening laws are examined. First, a bilinear softening definition is utilized. Then, an exponential curve is taken. Finally, a rational Bezier curve is tested. An ambiguity in choosing material parameters and softening curve definitions is discussed. Numerical results are compared with experimental outcomes recently reported in the literature. Two error measures are defined and used to quantitatively assess calculated maximum forces (nominal strengths) in comparison with experimental values as a primary criterion. In addition, the force—displacement curves are also analyzed. It is shown that all softening curves produce results consistent with the experimental data. Moreover, with different softening laws assumed, different initial fracture energies should be taken to obtain proper results.


Author(s):  
Tatjana Šoštarić ◽  
Marija Petrović ◽  
Jelena Milojković ◽  
Jelena Petrović ◽  
Marija Stanojević ◽  
...  

In this paper, the removal of methylene blue (MB) from aqueous solution by biosorption ontoapricot shellshas been investigated through batch experiments. Apricot shells were chosen as alocally available and abundant waste from fruit juice industry. Methylene blue is common pollutantof waste waters from textile industry.The influence of initial MB concentration on biosorption process has been studied. Theexperimental data have been analysed using Langmuir and Freundlichisotherm models. TheLangmuir model better fits to experimental data, which explain monolayer adsorption. Maximumbiosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shellswith biosorption capacities of similar adsorbents previously investigated indicates that apricotshells could be a promising biosorbent for removal of MB from aqueous solution.


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