Search results for: reaction control jet

Authors: Chandrashekar, R. T. Radhika, B. M. Venkatesha, S. Ananda, Shivalingegowda, T. S. Shashikumar, H. Ramachandra

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The kinetics of the oxidation of amitriptyline (AT) by sodium N-bromotoluene sulphonamide (C₆H₅SO₂NBrNa) has been studied in an acidic buffer medium of pH 1.2 at 303 K. The oxidation reaction of AT was followed spectrophotometrically at maximum wavelength, 410 nm. The reaction rate shows a first order dependence each on concentration of AT and concentration of sodium N-bromotoluene sulphonamide. The reaction also shows an inverse fractional order dependence at low or high concentration of HCl. The dielectric constant of the solvent shows negative effect on the rate of reaction. The addition of halide ions and the reduction product of BAT have no significant effect on the rate. The rate is unchanged with the variation in the ionic strength (NaClO₄) of the medium. Addition of reaction mixtures to be aqueous acrylamide solution did not initiate polymerization, indicating the absence of free radical species. The stoichiometry of the reaction was found to be 1:1 and oxidation product of AT is identified. The Michaelis-Menton type of kinetics has been proposed. The CH₃C₆H₅SO₂NHBr has been assumed to be the reactive oxidizing species. Thermodynamical parameters were computed by studying the reactions at different temperatures. A mechanism consistent with observed kinetics is presented.

Keywords: amitriptyline, bromamine-T, kinetics, oxidation

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Authors: Joshi Rajiv, Shah Priyank, Thavkar Amit, Rohira Poonam, Mehta Suyog

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Topical formulation containing minoxidil and finasteride helps hair growth in the treatment of male androgenetic alopecia. The objective of this study is to compare the irritation potential of three conventional formulations of minoxidil 5% + finasteride 0.1% topical solution of in human patch test. The study was a single centre, double blind, non-randomized controlled study in 53 healthy adult Indian subjects. Occlusive patch test for 24 hours was performed with three formulations of minoxidil 5% + finasteride 0.1% topical solution. Products tested included aqueous based minoxidil 5% + finasteride 0.1% (AnasureTM-F, Sun Pharma, India – Brand A), lipid based minoxidil 5% + finasteride 0.1% (Brand B) and aqueous based minoxidil 5% + finasteride 0.1% (Brand C). Isotonic saline 0.9% and 1% w/w sodium lauryl sulphate were included as negative control and positive control respectively. Patches were applied and removed after 24 hours. The skin reaction was assessed and clinically scored 24 hours after the removal of the patches under constant artificial daylight source using the Draize scale (0-4 points scale for erythema/dryness//wrinkles and for oedema). Follow-up was scheduled after one week to confirm recovery for any reaction. A combined mean score up to 2.0/8.0 indicates a product is “non-irritant” and a score between 2.0/8.0 and 4.0/8.0 indicates “mildly irritant” and a score above 4.0/8.0 indicates “irritant”. The procedure of the patch test followed the principles outlined by the Bureau of Indian Standards (BIS) (IS 4011:2018; Methods of Test for safety evaluation of Cosmetics-3rd revision). Fifty three subjects with mean age 31.9 years (25 males and 28 females) participated in the study. The combined mean score ± standard deviation were: 0.06 ± 0.23 (Brand A), 0.81 ± 0.59 (Brand B), 0.38 ± 0.49 (Brand C), 2.92 ± 0.47 (positive control) and 0.0 ± 0.0 (Negative control). This means the score of Brand A (Sun Pharma product) was significantly lower than that of Brand B (p=0.001) and that of Brand C (p=0.001). The combined mean erythema score ± standard deviation were: 0.06 ± 0.23 (Brand A), 0.81 ± 0.59 (Brand B), 0.38 ± 0.49 (Brand C), 2.09 ± 0.4 (Positive control) and 0.0 ± 0.0 (Negative control). The mean erythema score of Brand A was significantly lower than Brand B (p=0.001) and that of Brand C (p=0.001). Any reaction observed at 24hours after patch removal subsided in a week. All the three topical formulations of minoxidil 5% + finasteride 0.1% were non-irritant. Brand A of minoxidil 5% + finasteride 0.1% (Sun Pharma) was found to be the least irritant than Brand B and Brand C based on the combined mean score and mean erythema score in the human patch test as per the BIS, IS 4011:2018

Keywords: erythema, finasteride, irritation, minoxidil, patch test

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Authors: Burcu Kiren, Alattin CAkan, Nezihe Ayas

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Hydrogen will be arguably the best fuel in the future as it is the most abundant element in the universe. Hydrogen, as a fuel, is notably environmentally benign, sustainable and has high energy content compared to other sources of energy. It can be generated from both conventional and renewable sources. The hydrolysis reaction of metal hydrides provides an option for hydrogen production in the presence of a catalyst. In this study, Ni/dolomite catalyst was synthesized by the wet impregnation method for hydrogen production by hydrolysis reaction of sodium borohydride (NaBH4). Besides, the synthesized catalysts characterizations were examined by means of thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer –Emmett – Teller (BET) and scanning electron microscopy (SEM). The influence of reaction temperature (25-75 °C), reaction time (15-60 min.), amount of catalyst (50-250 mg) and active metal loading ratio (20,30,40 wt.%) were investigated. The catalyst prepared with 30 wt.% Ni was noted as the most suitable catalyst, achieving of 35.18% H₂ and hydrogen production rate of 19.23 mL/gcat.min at 25 °C at reaction conditions of 5 mL of 0.25 M NaOH and 100 mg NaBH₄, 100 mg Ni/dolomite.

Keywords: sodium borohydride, hydrolysis, catalyst, Ni/dolomite, hydrogen

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Authors: André Luis Lima de Oliveira, Vera Lúcia Viana do Nascimento, Victória Maura Silva Bermudez, Mauricio Nunes Kleinberg, João Carlos da Costa Assunção, José Osvaldo Beserra Carioca

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The objective of this study was to synthesize a triglyceride with high content of unsaturated fatty acids from salmon oil (Salmo salar L.) by esterification with glycerol catalyzed dealuminized zeolite. A kinetic study was conducted to determine the reaction order and the activation energy. A statistical study was conducted to determine optimal reaction conditions. Initially, the crude oil was refined salmon physically and chemically. The crude oil was hydrolyzed and unsaturated free fatty acids were separated by urea complexation method. An experimental project to verify the parameters (temperature, glycerin and catalyst) with the greatest impact on the reaction was developed. In experiments aliquots were taken at predetermined times to measure the amount of free fatty acids. Pareto, surface, contour and hub graphs were used to determine the factors that maximized the reaction. According to the graphs the best reaction conditions were: temperature 80 ° C, the proportion glycerine/oil 5: 1 and 1% of catalyst. The kinetic data showed that the system was compatible with a second-order reaction. After analyzing the rate constant versus temperature charts a value of 85.31 kJ/mol was obtained for the reaction activation energy.

Keywords: esterification, kinect, oil, salmon

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Authors: Mehdi Razeghi

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Background: The purpose of this case series was to quantify gait to study muscular dystrophy disease. In this research, the quantitative differences between normal and waddling gaits were assessed by force plate analysis. Methods: Nineteen myopathy patients and twenty normal subjects serving as the control group participated in this research. In this study, quantitative analyses of gait have been used to investigate the differences between the mobility of normal subjects and myopathy patients. This study was carried out at the Iranian Muscular Dystrophy Association in Boali Hospital, Tehran, Iran, from October 2015 to July 2020. Patient data were collected from Iranian Muscular Dystrophy Association members. individuals signed an informed consent form approved by the ethics committee of the Azad University. All of the gait tests were performed using a Kistler force platform. Participants walked at a self-selected speed, barefoot, independently, and without assistive devices. Results: Our findings indicate that there were no significant differences between the patients and the control group in the anterior-posterior components of the ground reaction forces; however, there were considerable differences in the force components between the groups in the medial-lateral and vertical directions of the ground reaction force. In addition, there were significant differences in the time parameters between the groups in the vertical and medial-lateral directions.

Keywords: biomechanics, force plate analysis, gait disorder, ground reaction force, kinetic analysis, myopathy disease, rehabilitation engineering

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Authors: Karim Hrratha, Khaled Essalahb, Christophe Morellc, Henry Chermettec, Salima Boughdiria

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Among the carbon-carbon bond formation types, allylation of active methylene compounds with cyclic Baylis-Hillman (BH) alcohols is a reliable and widely used method. This reaction is a very attractive tool in organic synthesis of biological and biodiesel compounds. Thus, in view of an insistent and peremptory request for an efficient and straightly method for synthesizing the desired product, a thorough analysis of various aspects of the reaction processes is an important task. The product afforded by the reaction of active methylene with BH alcohols depends largely on the experimental conditions, notably on the catalyst properties. All experiments reported that catalysis is needed for this reaction type because of the poor ability of alcohol hydroxyl group to be as a suitable leaving group. Within the catalysts, several transition- metal based have been used such as palladium in the presence of acid or base and have been considered as reliable methods. Furthemore, acid catalysts such as BF3.OEt2, BiX3 (X= Cl, Br, I, (OTf)3), InCl3, Yb(OTf)3, FeCl3, p-TsOH and H-montmorillonite have been employed to activate the C-C bond formation through the alkylation of active methylene compounds. Interestingly a report of a smoothly process for the ability of 4-imethyaminopyridine(DMAP) to catalyze the allylation reaction of active methylene compounds with cyclic Baylis-Hillman (BH) alcohol appeared recently. However, the reaction mechanism remains ambiguous, since the C- allylation process leads to an unexpected product (noted P1), corresponding to a direct allylation instead of conjugate allylation, which involves the most electrophilic center according to the electron withdrawing group CO effect. The main objective of the present theoretical study is to better understand the role of the DMAP catalytic activity as well as the process leading to the end- product (P1) for the catalytic reaction of a cyclic BH alcohol with active methylene compounds. For that purpose, we have carried out computations of a set of active methylene compounds varying by R1 and R2 toward the same alcohol, and we have attempted to rationalize the mechanisms thanks to the acid–base approach, and conceptual DFT tools such as chemical potential, hardness, Fukui functions, electrophilicity index and dual descriptor, as these approaches have shown a good prediction of reactions products.The present work is then organized as follows: In a first part some computational details will be given, introducing the reactivity indexes used in the present work, then Section 3 is dedicated to the discussion of the prediction of the selectivity and regioselectivity. The paper ends with some concluding remarks. In this work, we have shown, through DFT method at the B3LYP/6-311++G(d,p) level of theory that: The allylation of active methylene compounds with cyclic BH alcohol is governed by orbital control character. Hence the end- product denoted P1 is generated by direct allylation.

Keywords: DFT calculation, gas phase pKa, theoretical mechanism, orbital control, charge control, Fukui function, transition state

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Authors: L. Parisi

Abstract:

In this research work, neural networks were applied to classify two types of hip joint implants based on the relative hip joint implant side speed and three components of each ground reaction force. The condition of walking gait at normal velocity was used and carried out with each of the two hip joint implants assessed. Ground reaction forces’ kinetic temporal changes were considered in the first approach followed but discarded in the second one. Ground reaction force components were obtained from eighteen patients under such gait condition, half of which had a hip implant type I-II, whilst the other half had the hip implant, defined as type III by Orthoload®. After pre-processing raw gait kinetic data and selecting the time frames needed for the analysis, the ground reaction force components were used to train a MLP neural network, which learnt to distinguish the two hip joint implants in the abovementioned condition. Further to training, unknown hip implant side and ground reaction force components were presented to the neural networks, which assigned those features into the right class with a reasonably high accuracy for the hip implant type I-II and the type III. The results suggest that neural networks could be successfully applied in the performance assessment of hip joint implants.

Keywords: kinemic gait data, neural networks, hip joint implant, hip arthroplasty, rehabilitation engineering

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Authors: Chin-Chih Chiou, Tai-Yuan Su, Ti-Yu Chen, Wen-Yu Chiu, Chungyu Chen

Abstract:

The purpose of this study was to investigate the effect of reaction time (RT) or balance performance as the number of stimulus-response choices increases, the amount of information processing of 0-bit and 1-bit conditions based on Hick’s law, using the dual-task design. Eighteen children (age: 9.38 ± 0.27 years old) were recruited as the participants for this study, and asked to assess RT and balance performance separately and simultaneously as following five conditions: simple RT (0-bit decision), choice RT (1-bit decision), single balance control, balance control with simple RT, and balance control with choice RT. Biodex 950-300 balance system and You-Shang response timer were used to record and analyze the postural stability and information processing speed (RT) respectively for the participants. Repeated measures one-way ANOVA with HSD post-hoc test and 2 (balance) × 2 (amount of information processing) repeated measures two-way ANOVA were used to test the parameters of balance performance and RT (α = .05). The results showed the overall stability index in the 1-bit decision was lower than in 0-bit decision, and the mean deflection in the 1-bit decision was lower than in single balance performance. Simple RTs were faster than choice RTs both in single task condition and dual task condition. It indicated that the chronometric approach of RT could use to infer the attention requirement of the secondary task. However, this study did not find that the balance performance is interfered for children by the increasing of the amount of information processing.

Keywords: capacity theory, reaction time, Hick’s law, balance

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Authors: Deokyeong Choe, Sung Hun Youn, Younggon Kim, Chul Soo Shin

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L-Cysteine is extensively used as a supplement of pharmaceuticals, cosmetics, food and feed additives. It has obtained industrially by hydrolysis of human hair and poultry feathers. However, there are some problems such as the restriction of using materials from animals and the intractable waste pollution. The enzymatic conversion has been regarded as an environmental-friendly method. Currently, the biggest bottle-neck of enzymatic conversion is the low yield of L-cysteine due to the low substrate solubility. In this study, the method of enhancing the solubility of the substrate D,L-2-amino-Δ2-thiazoline-4-carboxylicacid (ATC) was developed and the enzymatic reaction at high concentration levels was performed. A large amount of substrate in aqueous solutions was dissolved by pH control using salts. As the pH of the solution increased, the solubility of ATC increased. It was thought that a shift of ATC from acid form (-COOH) to dissociated carboxylic group (-COO-) would improve its hydrophilicity leading to solubility increase. The highest solubility of ATC was 610 mM at pH 10.5, whereas the maximum reaction rate was obtained at pH 8.3. As a result, a high L-cysteine yield of 250 mM was achieved at pH 9.1, which was obtained from a combination of optimum pH conditions for ATC solubility and enzymatic conversion. This yield corresponds to approximately 18 times of that in previous reports.

Keywords: D, L-2-amino-Δ2-thiazoline-4-carboxylicacid, enzymatic conversion, high-substrate solubilization, L-Cysteine

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Authors: Zahid Shafiq, Li Liu, Dong Wang, Yong-Jun Chen

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As synthetic organic methods are increasingly concerned with the growing importance of sustainable chemistry, iodine recently has emerged as an inexpensive, non-toxic, readily available and environmentally benign catalyst for various organic transformations to afford the corresponding products in high yields with high regio- and chemoselectivity. Iodine has found widespread applications in various organic synthesis such as Michael addition, coupling reaction and also in the multicomponent synthesis where it can efficiently activate C=C, C=O, C=N, and so forth. Iodine not only has been shown to be an efficient mild Lewis acid in various processes, but also due to its moderate nature, and water tolerance, reactions catalyzed by iodine can be effectively carried out in neutral media under very mild conditions. We have successfully described an efficient procedure for the nucleophilic substitution of the Baylis-Hillman (BH) adducts and their corresponding acetates with indoles to get α-substitution product using catalytic Silver Triflate (AgOTf) as Lewis acid. At this point, we were interested to develop an environmentally benign catalytic system to effect this substitution reaction and to avoid the use of metal Lewis acid as a catalyst. Since, we observed the formation of -product during the course of the reaction, we also became interested to explore the reaction conditions in order to control regioselectivity and to obtain both regioisomers. The developed methodology resulted in regioselective substitution products with controlled selectivity. Further, the substitution products were used to synthesize various Tri- and Tetracyclo Azepino indole derivatives via reductive amination.

Keywords: indole, regioselective, Baylis-Hillman, substitution

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Authors: Mohammad Anwar, Shah Waliullah

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The development of science and technology in the present era has an urgent demand for the training of thinking of undergraduates. This requirement actively promotes research and teaching of basic theories, beneficial to the career development of students. This study clarified the dialectical relation between the thermodynamic equilibrium constant and reaction rate constant through the contrast thinking method. Findings reveal that both the isobaric Van't Hoff equation and the Arrhenius equation had four similar forms, and the change in the trend of both constants showed a similar law. By the derivation of the formation rate constant of the product (KY) and the consumption rate constant of the reactant (KA), the ratio of both constants at the end state indicated the nature of the equilibrium state in agreement with that of the thermodynamic equilibrium constant (K^θ (T)). This study has thus presented that the thermodynamic equilibrium constant contained the characteristics of microscopic dynamics based on the analysis of the reaction mechanism, and both constants are organically connected and unified. The reaction enthalpy and activation energy are closely related to each other with the same connotation.

Keywords: thermodynamic equilibrium constant, reaction rate constant, PBL teaching, dialectical relation, innovative thinking

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Authors: M. Abdoul-Hakim, A. Zeroual, H. Garmes

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2-Chlorobenzimidazoles are amphoteric compounds and versatile intermediates for the construction of polycyclic heterocycles. In this theoretical study performed by DFT at the B3LYP/6-311+G(d,p) level, we showed that the most likely route to obtain benzimidazo[1,2-d]oxadiazole from the reaction of 2-Chlorobenzimidazole with benzonitrile N-oxide involves the presence of anionic species, a concerted mechanism is not possible. The inclusion of the effect of the polar protic solvent (MeOH) favors the course of the reaction. The key interactions causing bond formation and breakage were identified by ELF topological analysis.

Keywords: benzimidazo[1, 2-d]oxadiazole, benzonitrile N-oxide, DFT, ELF, polycyclic heterocycles

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Authors: Salina Y. Saddick

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Mild gestational hyperglycemia (MGH) is a very common complication of pregnancy that is characterized by intolerance to glucose. The association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism to MGH has been previously reported. In this study, we evaluated the association between ACE polymorphism and the risk of MGH in a Saudi population. We conducted a case-control study in a population of 100 MGH patients and 100 control subjects. ACE gene polymorphism was analyzed by the novel approach of tetraprimer amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR). The frequency of ACE polymorphism was not associated with either alleles or genotypes in MGH patients. Glucose concentration was found to be significantly associated with the MGH group. Our study suggests that ACE genotypes were not associated with ACE polymorphism in a Saudi population.

Keywords: MGH, ACE, insertion polymorphism, deletion polymorphism

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Authors: Malee Santikunaporn, Neera Wongtyanuwat, Channarong Asavatesanupap

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Pyrolysis of waste oil is an effective process to produce high quality liquid fuels. In this work, pyrolysis experiments of waste oil over Y zeolite were carried out in a semi-batch reactor under a flow of nitrogen at atmospheric pressure and at different reaction temperatures (350-450 ^oC). The products were gas, liquid fuel, and residue. Only liquid fuel was further characterized for its composition and properties by using gas chromatography, thermogravimetric analyzer, and bomb calorimeter. Experimental results indicated that the pyrolysis reaction temperature significantly affected both yield and composition distribution of pyrolysis oil. An increase in reaction temperature resulted in increased fuel yield, especially gasoline fraction. To obtain high amount of fuel, the optimal reaction temperature should be higher than 350 ^oC. A presence of Y zeolite in the system enhanced the cracking activity. In addition, the pyrolysis oil yield is proportional to the catalyst quantity.

Keywords: gasoline, diesel, pyrolysis, waste oil, Y zeolite

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Authors: Kanda Wongwailikhit

Abstract:

Copper (I) oxide microparticles with the morphology of cubic and hollow sphere were synthesized with the assistance of a surfactant as the shape controller. Both particles were then subjected to a study of the catalytic activity and the results of shape effects of catalysts on rate of catalytic reaction was observed. The decolorizing reaction of crystal violet and sodium hydroxide was chosen and the decrease of reactant with respect to time was measured using a spectrophotometer. The result revealed that morphology of the crystal had no effect on the catalytic activity for the crystal violet reaction but contributed to total surface area predominantly.

Keywords: copper (I) oxide, catalytic activity, crystal violet

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Authors: Manjusha C. Padole, Parag A. Deshpande

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Density functional theory calculations were carried out for identification of an active heterogeneous catalyst to carry out Heck coupling reaction which is of pharmaceutical importance. One of the carbonaceous nanomaterials, heterofullerene, was designed for the reaction. Stability and reactivity of the proposed heterofullerenes (C59M, M = Pd/Ni) were established with insights into the metal-carbon bond, electron affinity and chemical potential. Adsorbent potentials of both the heterofullerenes were examined from the adsorption study of four halobenzenes (C6H5F, C6H5Cl, C6H5Br and C6H5I). Oxidative addition activities of all four halobenzenes were investigated by developing free energy landscapes over both the heterofullerenes for rate determining step (oxidative addition). C6H5I showed a good catalytic activity for the rate determining step. Thus, C6H5I was proposed as a suitable halobenzene and complete free energy landscapes for Heck coupling reaction were developed over C59Pd and C59Ni. Smaller activation barriers observed over C59Pd in comparison with C59Ni put us in a position to propose C59Pd to be an efficient heterofullerene for carrying Heck coupling reaction.

Keywords: metal-substituted fullerene, density functional theory, electron affinity, oxidative addition, Heck coupling reaction

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Authors: Juree Hong, Sanggeun Lee, Jungmok Seo, Taeyoon Lee

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We report a facile synthesis of metal nano particles (NPs) on graphene layer via galvanic displacement reaction between graphene-buffered copper (Cu) and metal ion-containing salts. Diverse metal NPs can be formed on graphene surface and their morphologies can be tailored by controlling the concentration of metal ion-containing salt and immersion time. The obtained metal NP-decorated single-layer graphene (SLG) has been used as hydrogen gas (H2) sensing material and exhibited highly sensitive response upon exposure to 2% of H2.

Keywords: metal nanoparticle, galvanic displacement reaction, graphene, hydrogen sensor

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Authors: S. Said, Asmaa A. Abdulrahman

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MoOₓ/Al₂O₃ based catalyst has long been widely used as an active catalyst in oxidative desulfurization reaction due to its high stability under severe reaction conditions and high resistance to sulfur poisoning. In this context, 4 & 9wt.% MoO₃ grafted on mesoporous γ-Al₂O₃ has been synthesized using the modified atomic layer deposition (ALD) method. Another MoO₃/Al₂O₃ sample was prepared by the conventional wetness impregnation (IM) method, for comparison. The effect of the preparation methods on the metal-support interaction was evaluated using different characterization techniques, including X-ray diffraction, X-ray photoelectron spectroscopy (XPS), N₂-physisorption, transmission electron microscopy (TEM), H₂- temperature-programmed reduction and FT-IR. Oxidative desulfurization (ODS) reaction of the model fuel oil was used as a probe reaction to examine the catalytic efficiency of the prepared catalysts. ALD method led to samples with much better physicochemical properties than those of the prepared one via the impregnation method. However, the 9 wt.%MoO₃/Al₂O₃ (ALD) catalyst in the ODS reaction of model fuel oil shows enhanced catalytic performance with ~90%, which has been attributed to the more Mo⁶⁺ surface concentrations relative to Al³⁺ with large pore diameter and surface area. The kinetic study shows that the ODS of DBT follows a pseudo first-order rate reaction.

Keywords: mesoporous Al₂O₃, xMoO₃/Al₂O₃, atomic layer deposition, wetness impregnation, ODS, DBT

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Authors: Rayenne Djemil

Abstract:

The mechanism of oxidation reaction of linoleic acid C18: 2 (9 cis12) by singlet oxygen 1O2 were theoretically investigated via using quantum chemical methods. We explored the four reaction pathways at PM3, Hartree-Fock HF and, B3LYP functional associated with the base 6-31G (d) level. The results are in favor of the first and the last reaction ways. The transition states were found by QST3 method. Thus the pathways between the transition state structures and their corresponding minima have been identified by the IRC calculations. The thermodynamic study showed that the four ways of oxidation of linoleic acid are spontaneous, exothermic and, the enthalpy values confirm that conjugate hydroperoxydes are the most favorable products.

Keywords: echanism, quantum mechanics, oxidation, linoleic acid H

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Authors: N. Naga Subrahmanyeswara Rao, Parag Arvind Deshpande

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Understanding nucleotide synthesis reaction of any organism is beneficial to know the growth of it as in Mycobacterium tuberculosis to design anti TB drug. One of the reactions of de novo pathway which takes place in all organisms was considered. The reaction takes places between phosphoribosyl pyrophosphate and orotate catalyzed by orotate phosphoribosyl transferase and divalent metal ion gives orotdine monophosphate, a nucleotide. All the reaction steps of three experimentally proposed mechanisms for this reaction were considered to develop kinetic rate expression. The model was validated using the data for four organisms. This model could successfully describe the kinetics for the reported data. The developed model can serve as a reliable model to describe the kinetics in new organisms without the need of mechanistic determination. So an organism-independent model was developed.

Keywords: mechanism, nucleotide, organism, tuberculosis

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Authors: Hamish Love, Navjot Bhullar, Nicola Schutte

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Self-control and related psychological constructs have been shown to have a large role in the improvement and maintenance of healthful dietary behaviour. However, self-control for diet, and related constructs such as motivation, level of conflict between tempting desires and dietary goals, and attentional bias for tempting food, have not been studied together to establish their relationships, to the author’s best knowledge. Therefore the aim of this paper was to conduct model testing on these constructs and evaluate how they relate to affect dietary outcomes. 400 Australian adult participants will be recruited via the Qualtrics platform and will be representative across age and gender. They will complete survey and reaction timing surveys to gather data on the five target constructs: Trait Self-control, Attentional Bias for Food, Dietary Goal-Desire Incongruence, Motivation for Dietary Self-control, and Satisfaction with Dietary Behaviour. A model of moderated mediation is predicted, whereby the initial predictor (Dietary Goal-Desire Incongruence) predicts the level of the outcome variable, Satisfaction with Dietary Behaviour. We hypothesise that the relationship between these two variables will be mediated by Trait Self-Control and that the extent that Trait Self-control is allowed to mediate dietary outcome is moderated by both Attentional Bias for Food and Motivation for Dietary Self-control. The analysis will be conducted using the PROCESS module in SPSS 23. The results of model testing in this current study will be valuable to direct future research and inform which constructs could be important targets for intervention to improve dietary outcomes.

Keywords: self-control, diet, model testing, attentional bias, motivation

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Authors: Miguel Pereira, Lígia Pimentel, Manuela Pintado

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Animal blood is a major by-product of slaughterhouses and still represents a cost and environmental problem in some countries. To be eliminated, blood should be stabilised by cooking and afterwards the slaughterhouses must have to pay for its incineration. In order to reduce the elimination costs and valorise the high protein content the aim of this study was the optimization of hydrolysis conditions, in terms of enzyme ratio and time, in order to obtain hydrolysates with biological activity. Two enzymes were tested in this assay: pepsin and proteases from Cynara cardunculus (cardosins). The latter has the advantage to be largely used in the Portuguese Dairy Industry and has a low price. The screening assays were carried out in a range of time between 0 and 10 h and using a ratio of enzyme/reaction volume between 0 and 5%. The assays were performed at the optimal conditions of pH and temperature for each enzyme: 55 °C at pH 5.2 for cardosins and 37 °C at pH 2.0 for pepsin. After reaction, the hydrolysates were evaluated by FPLC (Fast Protein Liquid Chromatography) and tested for their antioxidant activity by ABTS method. FPLC chromatograms showed different profiles when comparing the enzymatic reactions with the control (no enzyme added). The chromatogram exhibited new peaks with lower MW that were not present in control samples, demonstrating the hydrolysis by both enzymes. Regarding to the antioxidant activity, the best results for both enzymes were obtained using a ratio enzyme/reactional volume of 5% during 5 h of hydrolysis. However, the extension of reaction did not affect significantly the antioxidant activity. This has an industrial relevant aspect in what concerns to the process cost. In conclusion, the enzymatic blood hydrolysis can be a better alternative to the current elimination process allowing to the industry the reuse of an ingredient with biological properties and economic value.

Keywords: antioxidant activity, blood, by-products, enzymatic hydrolysis

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Authors: Y. A. Shapovalov, F. M. Gumerov, M. K. Nauryzbaev, S. V. Mazanov, R. A. Usmanov, A. V. Klinov, L. K. Safiullina, S. A. Soshin

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A flow-through installation was created and manufactured for the transesterification of triglycerides of fatty acids and production of biodiesel fuel under supercritical fluid conditions. Transesterification of rapeseed oil with ethanol was carried out according to two parameters: temperature and the ratio of alcohol/oil mixture at the constant pressure of 19 MPa. The kinetics of the yield of fatty acids ethyl esters (FAEE) was determined in the temperature range of 320-380 °C at the alcohol/oil molar ratio of 6:1-20:1. The content of the formed FAEE was determined by the method of correlation of the resulting biodiesel fuel by its kinematic viscosity. The maximum FAEE yield (about 90%) was obtained within 30 min at the ethanol/oil molar ratio of 12:1 and a temperature of 380 °C. When studying of transesterification of triglycerides, a kinetic model of an isothermal flow reactor was used. The reaction order implemented in the flow reactor has been determined. The first order of the reaction was confirmed by data on the conversion of FAEE during the reaction at different temperatures and the molar ratios of the initial reagents (ethanol/oil). Using the Arrhenius equation, the values of the effective constants of the transesterification reaction rate were calculated at different reaction temperatures. In addition, based on the experimental data, the activation energy and the pre-exponential factor of the transesterification reaction were determined.

Keywords: biodiesel, fatty acid esters, supercritical fluid technology, transesterification

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Authors: Dmitriy Yu. Korulkin, Ravshan M. Nuraliev, Raissa A. Muzychkina

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In this research paper, we investigated the main regularities of a radical bromination reaction of decalin. We studied the temperature effect, durations of reaction, frequency rate of process, ratio of initial components, type and number of the initiator on decalin bromination degree. We found specified optimum conditions of synthesis of a perbromodecalin by the method of a decalin bromination. We developed the technological flowchart of receiving a perbromodecalin and the mass balance of process on the first and the subsequent loadings of components. The results of the research of antibacterial and antifungal activity of synthesized bromoderivatives have been represented.

Keywords: decalin, optimum technology, perbromodecalin, radical bromination

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Authors: Carolin Anna Joy, Rohith K. R, Rehin Sulay, Parvathy Santhoshkumar, G.Anil Kumar, Vibin Ipe Thomas

Abstract:

Ullmann coupling reactions are gaining great relevance owing to their contribution in the synthesis of biologically and pharmaceutically important compounds. Palladium and many other heavy metals have proven their excellent ability in coupling reaction, but the toxicity matters. The first-row transition metal also possess toxicity, except in the case of iron and manganese. The suitability of manganese as a catalyst is achieving great interest in oxidation, reduction, C-H activation, coupling reaction etc. In this presentation, we discuss the thermo chemistry of ligand free manganese catalyzed C-O coupling reaction between phenol and aryl halide for the synthesis of biaryl ethers using Density functional theory techniques. The mechanism involves an oxidative addition-reductive elimination step. The transition state for both the step had been studied and confirmed using Intrinsic Reaction Coordinate (IRC) calculation. The barrier height for the reaction had also been calculated from the rate determining step. The possibility of other mechanistic way had also been studied. To achieve further insight into the mechanism, substrate having various functional groups is considered in our study to direct their effect on the feasibility of the reaction.

Keywords: Density functional theory, Molecular Modeling, ligand free, biaryl ethers, Ullmann coupling

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Authors: Hellal Abdelkader, Chafaa Salah, Boudjemaa Fouzia

Abstract:

A new, convenient, and high yielding procedure for the preparation of diethyl α-aminophosphonates in water via Kabachnik-Fields reaction by one-pot reaction of aromatic aldehydes, ortho-aminophenols, and dialkylphosphites in the presence of a low catalytic amount of citric, malic, tartaric, and oxalic acids as a natural, bi-functional, and highly stable catalyst is described, the obtained products were characterized by elemental analyses, molar conductance, magnetic susceptibility, FTIR, Uv-Vis spectral data, NMR-C, NMR-H, and NMR-P analyses.

Keywords: α-aminophosphonates, aminophenols, natural acids, aqueous media, Kabachnik-Fields reaction

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Authors: Salam M. Elhafez, Ahmed A. Ashour, Naglaa M. Elhafez, Ghada M. Elhafez, Azza M. Abdelmohsen

Abstract:

Patients suffering from gait disturbances are referred by having muscle group dysfunctions. There is a need for more studies investigating the contribution of muscle moments of the lower limb to the vertical ground reaction force using 3D gait analysis system. The purpose of this study was to investigate how the hip, knee and ankle moments in the sagittal plane contribute to the vertical ground reaction force in healthy subjects during normal speed of walking. Forty healthy male individuals volunteered to participate in this study. They were filmed using six high speed (120 Hz) Pro-Reflex Infrared cameras (Qualisys) while walking on an AMTI force platform. The data collected were the percentage contribution of the moments of the hip, knee and ankle joints in the sagittal plane at the instant of occurrence of the first peak, second peak, and the trough of the vertical ground reaction force. The results revealed that at the first peak of the ground reaction force (loading response), the highest contribution was generated from the knee extension moment, followed by the hip extension moment. Knee flexion and ankle plantar flexion moments produced high contribution to the trough of the ground reaction force (midstance) with approximately equal values. The second peak of the ground reaction force was mainly produced by the ankle plantar flexion moment. Conclusion: Hip and knee flexion and extension moments and ankle plantar flexion moment play important roles in the supporting phase of normal walking.

Keywords: gait analysis, ground reaction force, moment contribution, normal walking

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Authors: Zahra Neffah, Henda Kahalerras

Abstract:

A numerical study is made in a parallel-plate porous channel subjected to an oscillating flow and an exothermic chemical reaction on its walls. The flow field in the porous region is modeled by the Darcy–Brinkman–Forchheimer model and the finite volume method is used to solve the governing equations. The effects of the modified Frank-Kamenetskii (FKm) and Damköhler (Dm) numbers, the amplitude of oscillation (A), and the Strouhal number (St) are examined. The main results show an increase of heat and mass transfer rates with A and St, and their decrease with FKm and Dm.

Keywords: chemical reaction, heat and mass transfer, oscillating flow, porous channel

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Authors: Esma Gizem Daskiran, Mehmet Mustafa Daskiran

Abstract:

This paper investigates the effectiveness of two natural zeolites in reducing expansion of concrete due to alkali-silica reaction. These natural zeolites have different reactive silica content. Three aggregates; two natural sand and one crushed stone aggregate were used while preparing mortar bars in accordance with accelerated mortar bar test method, ASTM C1260. Performance of natural zeolites are compared by examining the expansions due to alkali silica reaction. Natural zeolites added to the mixtures at %10 and %20 replacement levels by weight of cement. Natural zeolite with high reactive silica content had better performance on reducing expansions due to ASR. In this research, using high reactive zeolite at %20 replacement level was effective in mitigating expansions.

Keywords: alkali silica reaction, natural zeolite, durability, expansion

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Authors: Deepti Mishra, K. K Pant, Xiu Song Zhao, Muxina Konarova

Abstract:

Catalytic transformation of simplest hydrocarbon methane into benzene and valuable chemicals over Mo/HZSM-5 has a great economic potential, however, it suffers serious hurdles due to the blockage in the micropores because of extensive coking at high temperature during methane dehydroaromatization (MDA). Under such conditions, it necessitates the design of micro/mesoporous ZSM-5, which has the advantages viz. uniform dispersibility of MoOx species, consequently the formation of active Mo sites in the micro/mesoporous channel and lower carbon deposition because of improved mass transfer rate within the hierarchical pores. In this study, we report a unique strategy to control the porous structures of ZSM-5 through a dual templating approach, utilizing C6 and C12 -surfactants as porogen. DFT studies were carried out to correlate the ZSM-5 framework development using the C6 and C12 surfactants with structure directing agent. The structural and morphological parameters of the synthesized ZSM-5 were explored in detail to determine the crystallinity, porosity, Si/Al ratio, particle shape, size, and acidic strength, which were further correlated with the physicochemical and catalytic properties of Mo modified HZSM-5 catalysts. After Mo incorporation, all the catalysts were tested for MDA reaction. From the activity test, it was observed that C6 surfactant-modified hierarchically porous Mo/HZSM-5(H) showed the highest benzene formation rate (1.5 μmol/gcat. s) and longer catalytic stability up to 270 min of reaction as compared to the conventional microporous Mo/HZSM-5(C). In contrary, C12 surfactant modified Mo/HZSM-5(D) is inferior towards MDA reaction (benzene formation rate: 0.5 μmol/gcat. s). We ascribed that the difference in MDA activity could be due to the hierarchically interconnected meso/microporous feature of Mo/HZSM-5(H) that precludes secondary reaction of coking from benzene and hence contributing substantial stability towards MDA reaction.

Keywords: hierarchical pores, Mo/HZSM-5, methane dehydroaromatization, coke deposition

Procedia PDF Downloads 51