Ltaief Lammari, Sana Ben Khlifa, Linda Hamed, Khalil Hamraoui, H. Kharroubi
The physical, mechanical and morphological data of foods are essential in the separation and aeration processes, whether in the case of transportation or storage, in order to preserve the freshness of these products, and in this context we try to predict and implement some experiments that will be validated through equations, where it is desirable to determine the relationships among the characteristics. Key physical and mechanical parameters, for example, fruits are often classified by size, but it may be more economical to develop a method that classifies them by weight when designing a machine, the relationship between weight and intermediate dimensions is essential. These physical and technical properties of the potato had to be evaluated to know the effect of surface conditioning, the limits of loading without damage, as well as to allow the volume of breathing during all stages of the life cycle especially in the case of harvesting, transportation and storage, which is also important for the design of harvesting and harvesting equipment. Psychiatric treatment. The shape of potato tubers is as complex as any agricultural product, therefore, in order to determine the mechanical and physical properties, it has become more and more necessary to find all the necessary data and prove the basic viscoelastic behavior of this material, especially since then. The product is consumed by all worlds.
{"title":"Determination of Physical and Mechanical Properties of Potatoes and the Importance in Food Chemistry","authors":"Ltaief Lammari, Sana Ben Khlifa, Linda Hamed, Khalil Hamraoui, H. Kharroubi","doi":"10.37358/rc.22.1.8503","DOIUrl":"https://doi.org/10.37358/rc.22.1.8503","url":null,"abstract":"\u0000The physical, mechanical and morphological data of foods are essential in the separation and aeration processes, whether in the case of transportation or storage, in order to preserve the freshness of these products, and in this context we try to predict and implement some experiments that will be validated through equations, where it is desirable to determine the relationships among the characteristics. Key physical and mechanical parameters, for example, fruits are often classified by size, but it may be more economical to develop a method that classifies them by weight when designing a machine, the relationship between weight and intermediate dimensions is essential. These physical and technical properties of the potato had to be evaluated to know the effect of surface conditioning, the limits of loading without damage, as well as to allow the volume of breathing during all stages of the life cycle especially in the case of harvesting, transportation and storage, which is also important for the design of harvesting and harvesting equipment. Psychiatric treatment. The shape of potato tubers is as complex as any agricultural product, therefore, in order to determine the mechanical and physical properties, it has become more and more necessary to find all the necessary data and prove the basic viscoelastic behavior of this material, especially since then. The product is consumed by all worlds.\u0000","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82336887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oriana Palma Calabokis, R. Perera, C. Rosales, Yamid Nu�ez, Jairo Segura, A. Arrieta
Nanocomposites of poly(lactic acid) with sepiolite needles (5 wt.%) were evaluated in terms of the mechanical and biofilm formation properties. The nanocomposite exhibited higher values of the Young�s modulus and tensile strength at break compared to the PLA, without detriment in the percent elongation at break. These improvements were related to the high aspect ratio of the nanoclay, the polymer-clay interactions, and the degree of dispersion. The growth of Pseudomonas aeruginosa on the surface of the PLA and nPLA materials was promoted in different conditions. Medium with different concentration of nutrients were used and also were compared the effect of the medium physical state (solid or liquid medium). Biofilms were formed in all the conditions. However, the nanocomposite presented a higher area coverage of microorganisms on its surface, possibly due to the positive effects of the nanoclay on the bacterial adhesion.
{"title":"Nanocomposite Poly(lactic acid)/sepiolite with Improved Mechanical and Biofilms Formation Properties","authors":"Oriana Palma Calabokis, R. Perera, C. Rosales, Yamid Nu�ez, Jairo Segura, A. Arrieta","doi":"10.37358/rc.22.1.8501","DOIUrl":"https://doi.org/10.37358/rc.22.1.8501","url":null,"abstract":"\u0000Nanocomposites of poly(lactic acid) with sepiolite needles (5 wt.%) were evaluated in terms of the mechanical and biofilm formation properties. The nanocomposite exhibited higher values of the Young�s modulus and tensile strength at break compared to the PLA, without detriment in the percent elongation at break. These improvements were related to the high aspect ratio of the nanoclay, the polymer-clay interactions, and the degree of dispersion. The growth of Pseudomonas aeruginosa on the surface of the PLA and nPLA materials was promoted in different conditions. Medium with different concentration of nutrients were used and also were compared the effect of the medium physical state (solid or liquid medium). Biofilms were formed in all the conditions. However, the nanocomposite presented a higher area coverage of microorganisms on its surface, possibly due to the positive effects of the nanoclay on the bacterial adhesion.\u0000","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73189992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, modified zeolite was used to improve p-xylene selectivity in toluene dis-proportionation process. ZSM-5 zeolite was modified by introducing the phosphorus/Germanium loading and vacuum UV treatment from He+O2 microwave plasma treatment. Results showed that the ZSM-5 zeolite impregnated with Germanium and phosphorus have high p-xylene selectivity (up to 33 %). A sharp decrease in the acidity properties was achieved after phosphorus loading. By Germanium loading, selectivity increased but conversion did not change much. Also, the highest p-xylene selectivity (47 %) was obtained by P/Ge ZSM-5 with VUV treatment at the highest WHSV of 85 h-1.
{"title":"Modification Strategy of ZSM-5 Zeolite for Enhancing p-Xylene Selectivity in Toluene Disproportionation","authors":"Siamak Shehni, Seyed Mostafa Tabatabaee Ghomsheh","doi":"10.37358/rc.22.1.8499","DOIUrl":"https://doi.org/10.37358/rc.22.1.8499","url":null,"abstract":"\u0000In this study, modified zeolite was used to improve p-xylene selectivity in toluene dis-proportionation process. ZSM-5 zeolite was modified by introducing the phosphorus/Germanium loading and vacuum UV treatment from He+O2 microwave plasma treatment. Results showed that the ZSM-5 zeolite impregnated with Germanium and phosphorus have high p-xylene selectivity (up to 33 %). A sharp decrease in the acidity properties was achieved after phosphorus loading. By Germanium loading, selectivity increased but conversion did not change much. Also, the highest p-xylene selectivity (47 %) was obtained by P/Ge ZSM-5 with VUV treatment at the highest WHSV of 85 h-1.\u0000","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83268062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mg(OH)2 whiskers were successfully prepared under mechanical stirring with D301 ion exchange resin and Mg(NO3)2. The products were systematically characterized by testing settling ratio, turbidity, and analyzing SEM, FT-IR. The results showed that Mg(OH)2 prepared with 0.05 or 0.1 mol/L Mg(NO3)2 had excellent dispersion, and the settling ratio was close to 100 % after 360 min; The time extension was extremely helpful to improve the dispersion; The dispersion of product was correspondingly good under pH value of about 9. The products synthesized with different concentrations and reaction time could reach nanoscale, and the product obtained using 0.05 mol/L Mg(NO3)2 for 4 h had whisker structure with a length of 10 im and had a lipophilicity. FT-IR analysis showed the product included some functional groups or fragments from the resin, which had a positive modification effect on the products. The preparation of Mg(OH)2 whisker with resin as raw material is simple, green, and environmentally friendly, which is worthy of further application.
{"title":"Preparation and Properties of Mg(OH)2 Whiskers by Ion Exchange Resin Method","authors":"Gang Li, Y. Wang, Fen-Dou Wang","doi":"10.37358/rc.22.1.8498","DOIUrl":"https://doi.org/10.37358/rc.22.1.8498","url":null,"abstract":"\u0000Mg(OH)2 whiskers were successfully prepared under mechanical stirring with D301 ion exchange resin and Mg(NO3)2. The products were systematically characterized by testing settling ratio, turbidity, and analyzing SEM, FT-IR. The results showed that Mg(OH)2 prepared with 0.05 or 0.1 mol/L Mg(NO3)2 had excellent dispersion, and the settling ratio was close to 100 % after 360 min; The time extension was extremely helpful to improve the dispersion; The dispersion of product was correspondingly good under pH value of about 9. The products synthesized with different concentrations and reaction time could reach nanoscale, and the product obtained using 0.05 mol/L Mg(NO3)2 for 4 h had whisker structure with a length of 10 im and had a lipophilicity. FT-IR analysis showed the product included some functional groups or fragments from the resin, which had a positive modification effect on the products. The preparation of Mg(OH)2 whisker with resin as raw material is simple, green, and environmentally friendly, which is worthy of further application.\u0000","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89349631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wu Fei, Li Haigang, C. Cheng, Zhang Hao, Shunxin Fei
Cognition to the metal-metal interactions is of vital importance for the catalytic process and would help exploring novel catalysts. In the present study, the model system of FexNiy (x + y = 6) bimetallic clusters was utilized to study how metal-metal interactions influence the catalytic performance. The formation energies of different FeNi clusters, the hydrogen chemisorption energies together with the maximum hydrogen capacity and the saturated hydrogen atoms desorption energies were calculated. Bimetallic clusters exhibit a superior performance than pure clusters. Especially, Fe2Ni4 cluster has the highest hydrogen loading capacity, the most facile hydrogen molecule dissociation activation energy barrier and the lowest hydrogen atom desorption energy, suggesting that it is easier to dissociate H2 and release the H atoms. As a consequence, by adjusting appropriate metal/metal ratios, it is possible to design bimetallic catalysts with excellent catalytic performance.
认识金属-金属相互作用对催化过程具有重要意义，有助于探索新型催化剂。本研究利用FexNiy (x + y = 6)双金属团簇模型体系研究金属-金属相互作用对催化性能的影响。计算了不同FeNi簇的形成能、氢的化学吸附能、最大氢容量和饱和氢原子的解吸能。双金属团簇表现出优于纯团簇的性能。特别是Fe2Ni4簇的载氢能力最高，氢分子解离活化能垒最易形成，氢原子脱附能最低，说明它更容易解离H2并释放H原子。因此，通过调整适当的金属/金属比例，可以设计出具有优异催化性能的双金属催化剂。
{"title":"Synergistic Effect of FeNi Bimetallic Clusters for the Catalytic of Hydrogen Dissociation and Desorption: A Density Functional Theory Study","authors":"Wu Fei, Li Haigang, C. Cheng, Zhang Hao, Shunxin Fei","doi":"10.37358/rc.21.3.8434","DOIUrl":"https://doi.org/10.37358/rc.21.3.8434","url":null,"abstract":"\u0000Cognition to the metal-metal interactions is of vital importance for the catalytic process and would help exploring novel catalysts. In the present study, the model system of FexNiy (x + y = 6) bimetallic clusters was utilized to study how metal-metal interactions influence the catalytic performance. The formation energies of different FeNi clusters, the hydrogen chemisorption energies together with the maximum hydrogen capacity and the saturated hydrogen atoms desorption energies were calculated. Bimetallic clusters exhibit a superior performance than pure clusters. Especially, Fe2Ni4 cluster has the highest hydrogen loading capacity, the most facile hydrogen molecule dissociation activation energy barrier and the lowest hydrogen atom desorption energy, suggesting that it is easier to dissociate H2 and release the H atoms. As a consequence, by adjusting appropriate metal/metal ratios, it is possible to design bimetallic catalysts with excellent catalytic performance.\u0000","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79055064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The esterification of acetic acid and n-propanol catalyzed by benzenesulfonic acid and its derivatives in the batch and continuous rectification tower was studied, in order to develop a new effective and green catalyst instead of the oxidative and corrosive sulfuric acid. A series of the comparison system with sulfuric acid was build for the targeted and fast evaluation of catalysts. The results showed that the catalytic esterification activity of p-phenolsulfonic acid and p-toluenesulfuric acid is very closed to sulfonic acid in the continuous rectification tower. Furthermore, the stability test for continuous esterification with p-toluenesulfuric acid presented that the high yield of n-propyl acetate could maintain 50 hours and stability. Therefore, p-phenolsulfonic acid and p-toluenesulfuric acid could be prospective substitutes for sulfuric acid for the continuous synthesis of n-propyl acetate in the rectification tower.
{"title":"Benzenesulfonic Acid - an Green Efficient Esterification Catalysts for Continuous Synthesis of n-propyl Acetate","authors":"Zhijun Xia","doi":"10.37358/RC.21.2.8423","DOIUrl":"https://doi.org/10.37358/RC.21.2.8423","url":null,"abstract":"The esterification of acetic acid and n-propanol catalyzed by benzenesulfonic acid and its derivatives in the batch and continuous rectification tower was studied, in order to develop a new effective and green catalyst instead of the oxidative and corrosive sulfuric acid. A series of the comparison system with sulfuric acid was build for the targeted and fast evaluation of catalysts. The results showed that the catalytic esterification activity of p-phenolsulfonic acid and p-toluenesulfuric acid is very closed to sulfonic acid in the continuous rectification tower. Furthermore, the stability test for continuous esterification with p-toluenesulfuric acid presented that the high yield of n-propyl acetate could maintain 50 hours and stability. Therefore, p-phenolsulfonic acid and p-toluenesulfuric acid could be prospective substitutes for sulfuric acid for the continuous synthesis of n-propyl acetate in the rectification tower.","PeriodicalId":21296,"journal":{"name":"Revista de Chimie","volume":"36 1","pages":"94-101"},"PeriodicalIF":0.0,"publicationDate":"2021-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78041269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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