PSJD - Yadda

1

The influence of the catalyst on the kinetics of ethyl metacrylate synthesis

100%

Grzesik M., Witczak T.

Polish Journal of Chemical Technology

|

2007

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vol. 9

|

issue 1

7-9

EN

The synthesis of ethyl metacrylate in the liquid phase was studied. Tungstophosphoric and molybdophosphoric acids, which belong to heteropolyacids group, were used as a catalyst. The chemical compounds from this group are often utilized in the catalysis with regard to their activity and selectivity. The rate equations, reaction rate constants and equilibrium constants have been determined. The reaction order and the kinetic parameters of the kinetic relations were determined by the integral method. All rate equations are formulated with activities taking the non ideal effects of the compounds into consideration. It was found that the kinetics of the esterification of the presented reactions was non-elementary

2

A biomechanical model correlating shoulder kinetics to pain in young baseball pitchers

100%

Keeley D. W., Oliver G. D., Dougherty C. P.

Journal of Human Kinetics

|

2012

|

vol. 34

|

issue 1

15-20

EN

Previous work has postulated that shoulder pain may be associated with increases in both peak shoulder anterior force and peak shoulder proximal force. Unfortunately these relationships have yet to be quantified. Thus, the purpose of this study was to associate these kinetic values with reported shoulder pain in youth baseball pitchers. Nineteen healthy baseball pitchers participated in this study. Segment based reference systems and established calculations were utilized to identify peak shoulder anterior force and peak shoulder proximal force. A medical history questionnaire was utilized to identify shoulder pain. Following collection of these data, the strength of the relationships between both peak shoulder anterior force and peak shoulder proximal force and shoulder pain were analyzed. Although peak anterior force was not significantly correlated to shoulder pain, peak proximal force was. These results lead to the development of a single variable logistic regression model able to accurately predict 84.2% of all cases and 71.4% of shoulder pain cases. This model indicated that for every 1 N increase in peak proximal force, there was a corresponding 4.6% increase in the likelihood of shoulder pain. The magnitude of peak proximal force is both correlated to reported shoulder pain and capable of being used to accurately predict the likelihood of experiencing shoulder pain. It appears that those pitchers exhibiting high magnitudes of peak proximal force are significantly more likely to report experiencing shoulder pain than those who generate lower magnitudes of peak proximal force.

3

Kinetics and Thermodynamic Studies of Corrosion Inhibition of Mild Steel Using Methanolic Extract of Erigeron floribundus (Kunth) in 2 M HCl Solution

100%

Abeng F. E., Idim V. D., Nna P. J.

World News of Natural Sciences

|

2017

|

vol. 10

26-38

EN

The investigation of kinetics and thermodynamics of the corrosion of mild steel in a 2 M HCl solution using methanolic extract of Erigeron floribundus was carried out by means of gravimetric techniques. The results obtained indicate that the extract retarded corrosion. The inhibition efficiency was seen to increase with increase in concentration of the inhibitor, as well as with increase in temperature. The values of activation energy (Ea) obtained indicate a chemisorptions mechanism, whereas the value of Gibb free energy (ΔGoads) indicates a spontaneous adsorption of the extract components on the metal surface. Kinetic modelling of the experimental data obeys first order reaction. The adsorption of methanolic extract of Erigeron floribundus onto the mild steel surface followed the Langmuir adsorption isotherm model. Therefore, the extract functions as good corrosion inhibitor for mild steel in hydrochloric acid.

4

Ground Reaction Force and Valgus Knee Loading during Landing after a Block in Female Volleyball Players

100%

Zahradnik D., Uchytil J., Farana R., Jandacka D.

Journal of Human Kinetics

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2014

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vol. 40

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issue 1

67-75

EN

A non-contact anterior cruciate ligament (ACL) injury is both a serious and very common problem in volleyball. The aim of the study was to determine the association between stick, step-back, and run-back landings after a block and select risk factors of ACL injuries for female professional volleyball players. The research sample involved fourteen female professional volleyball players. Two force plates were used to determine ground reaction forces. Eight infrared cameras were employed to collect the kinematic data. The one-factor repeated-measures analysis of variance, where the landing type was the factor, was used for comparing the valgus moment and ground reaction force on the right lower limb. ANOVA showed that the type of landing has a main effect on the valgus moment on the right lower limb (F) = 5.96, p = 0.019df = 1.18, partial ƞ2 = 0.239 and SP = 0.693). Furthermore, it did not show a main effect on the vertical reaction force on the right lower limb ((F)=2.77, p=0.090, df=1.55, partial ƞ2= 0.128 and SP=0.448). The highest valgus moment occurred during the run-back landing. This moment, however, did not have any effect within the first 100 ms after initial contact with the ground, but rather upon the subsequent motion carried out when stepping back off the net. A comparison between a run-back landing and a step-back landing showed relevant higher values of vertical ground reaction forces during the run-back landing.

5

Biomechanical Differences Associated with Two Different Load Carriage Systems and their Relationship to Economy

100%

Lloyd R., Cooke C.

Human Movement

|

2011

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vol. 12

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issue 1

65-74

EN

Purpose. To explore relationships between load carriage economy and the kinematics and kinetics of load carriage using both a backpack (BP) and a double pack (DP). Basic procedures. Nine participants walked on a treadmill at gradients of between 27% downhill and 20% uphill, and over a force plate on level ground, at a speed of 3 km.h-1. Expired air was collected throughout the treadmill experiment and all experiments were filmed for subsequent biomechanical analysis. The relative economy of load carriage was expressed in terms of the Extra Load Index (ELI). Main findings. There was a tendency for the double pack system to be associated with better economy than the BP. The double pack system provoked significantly less forward lean than the backpack and the horizontal displacement of the CoM was also smaller for the double pack system and both of these factors were strongly related to economy. There was, however, a greater range of motion of the trunk in the DP condition and this was also associated with improved economy. Conclusions. The results suggest that the DP was associated with smaller perturbations in gait than the BP and that this represents an advantage in terms of economy. In particular freedom of movement of the trunk in the sagittal plane may be an important consideration in the efficiency of load carriage systems.

6

Kinetic modeling of simultaneous saccharification and fermentation of corn starch for ethanol production

100%

Białas W., Czerniak A., Szymanowska-Powałowska D.

|

2014

|

vol. 61

|

issue 1

153-162

EN

Fuel ethanol production, using a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed using Saccharomyces cerevisiae and a granular starch hydrolyzing enzyme. The quantitative effects of mash concentration, enzyme dose and pH were investigated with the use of a Box-Wilson central composite design protocol. Proceeding from results obtained in optimal fermentation conditions, a kinetics model relating the utilization rates of starch and glucose as well as the production rates of ethanol and biomass was tested. Moreover, scanning electron microscopy (SEM) was applied to investigate corn starch granule surface after the SFF process. A maximum ethanol concentration of 110.36 g/l was obtained for native corn starch using a mash concentration of 25%, which resulted in ethanol yield of 85.71%. The optimal conditions for the above yield were found with an enzyme dose of 2.05 ml/kg and pH of 5.0. These results indicate that by using a central composite design, it is possible to determine optimal values of the fermentation parameters for maximum ethanol production. The investigated kinetics model can be used to describe SSF process conducted with granular starch hydrolyzing enzymes. The SEM micrographs reveal randomly distributed holes on the surface of granules.

7

The Effect of Disaccharide Concentration in a Liquid Binder on The Mechanisms and Kinetics of Disc Granulation

100%

Obraniak A., Gluba T.

Chemical and Process Engineering

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2017

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vol. 38

|

issue 2

8

KINETIC CHARACTERISATION OF CATALYSTS FOR METHANOL SYNTHESIS

100%

Ledakowicz S., Nowicki L., Petera J., Nizioł J., Kowalik P., Gołębiowski A.

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vol. 34

|

issue 4

497-506

EN

The results of activity studies of four catalysts in methanol synthesis have been presented. A standard industrial catalyst TMC-3/1 was compared with two methanol catalysts promoted by the addition of magnesium and one promoted by zirconium. The kinetic analysis of the experimental results shows that the Cu/Zn/Al/Mg/1 catalyst was the least active. Although TMC-3/1 and Cu/Zn/Al/Mg/2 catalysts were characterised by a higher activity, the most active catalyst system was Cu/Zn/Al/Zr. The activity calculated for zirconium doped catalyst under operating conditions was approximately 30% higher that of TMC-3/1catalyst. The experimental data were used to identify the rate equations of two types - one purely empirical power rate equation and the other one - the Vanden Bussche & Froment kinetic model of methanol synthesis. The Cu/ZnO/Al2O3 catalyst modified with zirconium has the highest application potential in methanol synthesis.

9

The comparative gait effects of select walking surfaces using kinetic and EMG analyses

100%

Slaughter S., Butler P., Capozzella H., Nguyen A., Hutcheson L.

Human Movement

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2012

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vol. 13

|

issue 3

198-203

EN

Purpose. This study investigated the EMG characteristics of muscles crossing the knee and the kinetics of the lower extremity during side-slope walking and other activities of daily living. We studied the difference in EMG data of the medial gastrocnemius and vastus lateralis muscles bilaterally and the relative rotation of the thigh to leg. Methods. Eleven outdoor workers (47.3 ± 13.9 years old) were recruited for this study. Participants walked on a 0° flat surface, 5° and 10° side-sloped surfaces, 10° inclined treadmill and ascended stairs. The EMG activity and rotation about a vertical axis during stance phase were analyzed. Results. Except for minor variations, ANOVA showed no significant difference in EMG activity between the walking surfaces, furthermore, the relative rotation of thigh-to-leg showed little or no differences between the variables. Multivariate ANOVA showed p-values between 0.1602 and 0.9943 when comparing the EMG data of all side-sloped surfaces. The relative rotation of the thigh to the leg showed p-values of 0.7837 and 0.9813 when comparing the left 0° to 10° and right 0° to 10°, respectively. Conclusions. The results of this study indirectly indicate that when considering rotation about a vertical axis and EMG activity, there is little difference in knee joint loading.

10

Application of artificial neural nerworks in oxidation kinetic analysis of nanocomposites

100%

Straszko J., Biedunkiewicz A., Strzelczak A.

Polish Journal of Chemical Technology

|

2008

|

vol. 10

|

issue 3

21-28

EN

This study concerns the application of artificial neural networks in oxidation kinetic analysis of ceramic nanocomposites. The oxidation of the Ti-Si-C ceramic nanocomposite in dry air was studied. The size of the nanoparticles was determined by scanning electron microscopy (SEM). The gaseous oxidation products were analysed by mass spectroscopy (MS) while the solid oxidation products by X-ray diffraction (XRD). The kinetic analysis of the oxidation was based on the Coats-Redfern equation. The kinetic models were identified for the consecutive stages and then the A and E parameters of the Arrhenius equations were evaluated. Artificial neural networks were used at each step of the kinetic calculations.

11

Modelling Grain Growth Kinetics in Steels

88%

Napoli G., Di Schino A.

Archives of Metallurgy and Materials

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2018

|

vol. 63

|

issue 2

12

Adsorptive removal of cochineal red a dye from aqueous solutions using yeast

88%

Borysiak M., Gabruś E., Borysiak M., Gabruś E.

Chemical and Process Engineering

|

2020

|

vol. 41

|

issue 2

13

Adsorption of Zn(II) ions from aqueous environment by surface modified Strychnos potatorum seeds, a low cost adsorbent

88%

Kumar P. S.

Polish Journal of Chemical Technology

|

2013

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vol. 15

|

issue 3

35-41

EN

The surface modified Strychnos potatorum seeds (SMSP), an agricultural waste has been developed into an effective adsorbent for the removal of Zn(II) ions from aqueous environment. The Freundlich model provided a better fit with the experimental data than the Langmuir model as revealed by a high coefficient of determination values and low error values. The kinetics data fitted well into the pseudo-second order model with the coefficient of determination values greater than 0.99. The influence of particle diffusion and film diffusion in the adsorption process was tested by fitting the experimental data with intraparticle diffusion, Boyd kinetic and Shrinking core models. Desorption experiments were conducted to explore the feasibility of regenerating the spent adsorbent and the adsorbed Zn(II) ions from spent SMSP was desorbed using 0.3 M HCl with the efficiency of 93.58%. The results of the present study indicates that the SMSP can be successfully employed for the removal of Zn(II) ions from aqueous environment.

14

Biochemical characterization of a catalase from Vibrio vulnificus, a pathogen that causes gastroenteritis

88%

Pei J., Wang H., Wu L., Xia S., Xu C., Zheng B., Li T., Jiang Y.

|

2017

|

vol. 64

|

issue 3

543-549

EN

Vibrio vulnificus is a virulent human pathogen causing gastroenteritis and possibly life threatening septicemia in patients. Most V. vulnificus are catalase positive and can deactivate peroxides, thus allowing them to survive within the host. In the study presented here, a catalase from V. vulnificus (CAT-Vv) was purified to homogeneity after expression in Escherichia coli. The kinetics and function of CAT-Vv were examined. CAT-Vv catalyzed the reduction of H2O2 at an optimal pH of 7.5 and temperature of 35°C. The Vmax and Km values were 65.8±1.2 U/mg and 10.5±0.7 mM for H2O2, respectively. Mutational analysis suggests that amino acids involved in heme binding play a key role in the catalysis. Quantitative reverse transcription-PCR revealed that in V. vulnificus, transcription of CAT-Vv was upregulated by low salinity, heat, and oxidative stresses. This research gives new clues to help inhibit the growth of, and infection by V. vulnificus.

15

A kinetic study on drinking water denitrification using a membrane bioreactor

88%

Petrovič A., Goršek A., Simonič M.

Open Chemistry

|

2015

|

vol. 13

|

issue 1

EN

This study determines the basic parameters of Monod kinetics for microbial growth within a membrane bioreactor using the Zenon ZeeWeed 10 MBR system. The influent nitrate concentration was kept at 70 ± 2 mg L-1 NO3ˉ. During the experiments a constant concentration of activated sludge was maintained at approximately 0.76 g L-1 under anoxic conditions. Sucrose was added to the activated sludge as a carbon source. The Monod kinetic parameters were calculated by numerical interpolation, by considering experimental data. The maximum specific growth rate of the biomass was determined to be 0.31 h-1, half-saturation constant 5.4 mg L-1, and yield coefficient 0.35 mg biomass mg-1 COD. Afterwards, a dynamic simulation was performed within the calculated parameters. The dynamic concentration profiles for substrate and biomass were determined at different dilution rates within the range of 0.8 to 5 d-1.

16

Exploratory Investigation of Impact Loads During the Forward Handspring Vault

88%

Penitente G., Sands W. A.

Journal of Human Kinetics

|

2015

|

vol. 46

|

issue 1

59-68

EN

The purpose of this study was to examine kinematic and kinetic differences in low and high intensity hand support impact loads during a forward handspring vault. A high-speed video camera (500 Hz) and two portable force platforms (500 Hz) were installed on the surface of the vault table. Two-dimensional analyses were conducted on 24 forward handspring vaults performed by 12 senior level, junior Olympic program female gymnasts (16.9 ±1.4 yr; body height 1.60 ±0.1 m; body mass 56.7 ±7.8 kg). Load intensities at impact with the vault table were classified as low (peak force < 0.8 × body weight) and high (peak force > 0.8 × body weight). These vaults were compared via crucial kinetic and kinematic variables using independent t-tests and Pearson correlations. Statistically significant (p < 0.001) differences were observed in peak force (t(24) = 4.75, ES = 3.37) and time to peak force (t(24) = 2.07, ES = 1.56). Statistically significant relationships between the loading rate and time to peak force were observed for high intensity loads. Peak force, time to peak force, and a shoulder angle at impact were identified as primary variables potentially involved in the determination of large repetitive loading rates on the forward handspring vault.

17

Esterification of palmitic acid with epichlorohydrin on anion exchange resin catalyst

88%

Muresan E., Oprea S., Malutan T., Vata M.

Open Chemistry

|

2007

|

vol. 5

|

issue 3

715-726

EN

The esterification reaction of palmitic acid with epichlorohydrin catalyzed by an anionic macroporous resin was studied. Purolite A-500 resin proved to be a very effective catalyst in the synthesis of 3-chloro-2-hydroxypropyl palmitate. The effects of certain parameters such as speed of agitation, catalyst particle size, catalyst loading, temperature, initial molar ratio between reactants on the rate of reaction were studied. It was found that the overall rate is intrinsically kinetically controlled. The structure of synthesized ester was confirmed by FTIR and 1H NMR analyses. [...]

18

KINETIC CHARACTERISATION OF CATALYSTS FOR METHANOL SYNTHESIS

88%

Ledakowicz S., Nowicki L., Petera J., Nizioł J., Kowalik P., Gołębiowski A.

Chemical and Process Engineering

|

2013

|

issue 4

19

Modelling and experimental investigation of waste tyre pyrolysis process in a laboratory reactor

88%

Rudniak L., Machniewski P. M.

Chemical and Process Engineering

|

2017

|

vol. 38

|

issue 3

20

Kinetics of cometabolic biodegradation of 4-chlorophenol and phenol by Stenotrophomonas maltophilia KB2

88%

Gąszczak A., Bartelmus G., Greń I., Rotkegel A., Janecki D.

Chemical and Process Engineering

|

2018

|

vol. 39

|

issue 4

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The influence of the catalyst on the kinetics of ethyl metacrylate synthesis

A biomechanical model correlating shoulder kinetics to pain in young baseball pitchers

Kinetics and Thermodynamic Studies of Corrosion Inhibition of Mild Steel Using Methanolic Extract of Erigeron floribundus (Kunth) in 2 M HCl Solution

Ground Reaction Force and Valgus Knee Loading during Landing after a Block in Female Volleyball Players

Biomechanical Differences Associated with Two Different Load Carriage Systems and their Relationship to Economy

Kinetic modeling of simultaneous saccharification and fermentation of corn starch for ethanol production

The Effect of Disaccharide Concentration in a Liquid Binder on The Mechanisms and Kinetics of Disc Granulation

KINETIC CHARACTERISATION OF CATALYSTS FOR METHANOL SYNTHESIS

The comparative gait effects of select walking surfaces using kinetic and EMG analyses

Application of artificial neural nerworks in oxidation kinetic analysis of nanocomposites

Modelling Grain Growth Kinetics in Steels

Adsorptive removal of cochineal red a dye from aqueous solutions using yeast

Adsorption of Zn(II) ions from aqueous environment by surface modified Strychnos potatorum seeds, a low cost adsorbent

Biochemical characterization of a catalase from Vibrio vulnificus, a pathogen that causes gastroenteritis

A kinetic study on drinking water denitrification using a membrane bioreactor

Exploratory Investigation of Impact Loads During the Forward Handspring Vault

Esterification of palmitic acid with epichlorohydrin on anion exchange resin catalyst

KINETIC CHARACTERISATION OF CATALYSTS FOR METHANOL SYNTHESIS

Modelling and experimental investigation of waste tyre pyrolysis process in a laboratory reactor

Kinetics of cometabolic biodegradation of 4-chlorophenol and phenol by Stenotrophomonas maltophilia KB2