Pub Date : 2022-01-01DOI: 10.11648/j.sjc.20221001.13
C. Mitan, E. Bartha, C. Draghici, M. Cǎproiu, Petru A. Filip, Robert Michael Moriarty
{"title":"Hopf Fibration on Relationship Between Dihedral Angle θ<sub>HnHn+1</sub>[deg] and Vicinal Angle ϕ[deg], Angles Calculated from NMR Data with 3-Shere Approach and Java Script","authors":"C. Mitan, E. Bartha, C. Draghici, M. Cǎproiu, Petru A. Filip, Robert Michael Moriarty","doi":"10.11648/j.sjc.20221001.13","DOIUrl":"https://doi.org/10.11648/j.sjc.20221001.13","url":null,"abstract":"","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88487630","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}
Pub Date : 2022-01-01DOI: 10.11648/j.sjc.20221001.12
Bianca Elena Popovici, M. Mitrică, Moga Marius
{"title":"Eating Patterns in Children, an Issue for Future Health Policy","authors":"Bianca Elena Popovici, M. Mitrică, Moga Marius","doi":"10.11648/j.sjc.20221001.12","DOIUrl":"https://doi.org/10.11648/j.sjc.20221001.12","url":null,"abstract":"","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79838631","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}
Pub Date : 2022-01-01DOI: 10.11648/j.sjc.20221001.11
A. Gueye, Papa Samba Camara, Mbossé Ndiaye-Guèye, Sofia Zazouli, Farba Bouyagui Tamboura, O. Diouf, N. Gruber, Mohamed Lamine Gaye
The use of 1,5-bis (phenyl (pyridin-2-yl) methylene) carbonohydrazide (H2L) in the coordination chemistry of lanthanides (III) yielded complexes in which two ligand molecules are present. The synthesis was carried out using a Ln/H2L ratio of 1/2 to lead mononuclear complexes of [Ln(H2L)2(η -NO3)3-x](NO3)x (Ln=La (1), Sm (4), Gd (6) and Yb (7)), [Ln(H2L)2(NO3)3] (Ln=Pr(2), Eu(5) and a co-crystal {[Nd(H2L)2(η -NO3)2(η -NO3)], [Nd(H2L)2(η -NO3)(h NO3)(H2O)]}.(NO3).2CH3OH} (3). The structures of the complexes (2) and (3)were solved by X-ray crystallography on a single crystal. In the mononuclear complex of Pr, two neutral ligand molecules act in tridentate fashion. In the co-crystal complex, one of the Nd atom is coordinated by two ligand molecules acting tridentately in neutral form and three nitrate anions acting in bidentate fashion while the second Nd atom is coordinated by two ligand molecules acting tridentately in neutral form, one monodentate nitrate anion, one bidentate nitrate anion and one water molecule. The neutrality of the complex is ensured by one free nitrate anion. Two free methanol molecules are present. Complex (2) crystallizes in the triclinic space group P-1 with the following parameters: a=10.128 (2) Å, b=12.2285 (19) Å, c=20.816 (5) Å, α=85.634 (4), β=81.870 (4)°, γ=87.210 (5)°, V=2542.9 (9) Å, Z=2, R1=0.0640, wR2=0.1377. Complex (3) crystallizes in the monoclinic space group P21/c with the following parameters: a=10.4554 (12) Å, b=44.089 (6) Å, c=23.212 (3) Å, β=90.851 (2)°, V=10699 (2) Å, Z=4, R1=0.0630, wR2=0.1690. The coordination sphere of the twelve-coordinated Pr III atom is best described as distorted icosahedron. In the co-crystal one of the Nd atom is eleven-coordinated while the second Nd atom is ten-coordinated. The environments around the Nd atoms are respectively best described as distorted pentacapped trigonal prism and a distorted bicapped square antiprism, respectively. Supramolecular structures are consolidated by numerous hydrogen bonds.
{"title":"Synthesis, Spectroscopic, Characterization and X-ray Structures of Lanthanide(III) Complexes Derived from 1,5-bis(phenyl(pyridin-2-yl)methylene)carbonohydrazide","authors":"A. Gueye, Papa Samba Camara, Mbossé Ndiaye-Guèye, Sofia Zazouli, Farba Bouyagui Tamboura, O. Diouf, N. Gruber, Mohamed Lamine Gaye","doi":"10.11648/j.sjc.20221001.11","DOIUrl":"https://doi.org/10.11648/j.sjc.20221001.11","url":null,"abstract":"The use of 1,5-bis (phenyl (pyridin-2-yl) methylene) carbonohydrazide (H2L) in the coordination chemistry of lanthanides (III) yielded complexes in which two ligand molecules are present. The synthesis was carried out using a Ln/H2L ratio of 1/2 to lead mononuclear complexes of [Ln(H2L)2(η -NO3)3-x](NO3)x (Ln=La (1), Sm (4), Gd (6) and Yb (7)), [Ln(H2L)2(NO3)3] (Ln=Pr(2), Eu(5) and a co-crystal {[Nd(H2L)2(η -NO3)2(η -NO3)], [Nd(H2L)2(η -NO3)(h NO3)(H2O)]}.(NO3).2CH3OH} (3). The structures of the complexes (2) and (3)were solved by X-ray crystallography on a single crystal. In the mononuclear complex of Pr, two neutral ligand molecules act in tridentate fashion. In the co-crystal complex, one of the Nd atom is coordinated by two ligand molecules acting tridentately in neutral form and three nitrate anions acting in bidentate fashion while the second Nd atom is coordinated by two ligand molecules acting tridentately in neutral form, one monodentate nitrate anion, one bidentate nitrate anion and one water molecule. The neutrality of the complex is ensured by one free nitrate anion. Two free methanol molecules are present. Complex (2) crystallizes in the triclinic space group P-1 with the following parameters: a=10.128 (2) Å, b=12.2285 (19) Å, c=20.816 (5) Å, α=85.634 (4), β=81.870 (4)°, γ=87.210 (5)°, V=2542.9 (9) Å, Z=2, R1=0.0640, wR2=0.1377. Complex (3) crystallizes in the monoclinic space group P21/c with the following parameters: a=10.4554 (12) Å, b=44.089 (6) Å, c=23.212 (3) Å, β=90.851 (2)°, V=10699 (2) Å, Z=4, R1=0.0630, wR2=0.1690. The coordination sphere of the twelve-coordinated Pr III atom is best described as distorted icosahedron. In the co-crystal one of the Nd atom is eleven-coordinated while the second Nd atom is ten-coordinated. The environments around the Nd atoms are respectively best described as distorted pentacapped trigonal prism and a distorted bicapped square antiprism, respectively. Supramolecular structures are consolidated by numerous hydrogen bonds.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83000718","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}
Pub Date : 2021-09-06DOI: 10.11648/J.SJC.20210905.11
Iortyom Susan Doofan, Kukwa Donald, Iornumbe Esther Nguumbur, A. Gbaa, Ijuo Godwin
While metal carboxylates are by no means rare or inaccessible, complete characterization with notable exception of acetates is largely neglected hence a deficiency within the carboxylate literature giving rise to discrepancies within the characterization data available thus, spectroscopic properties of synthesized sodium metal carboxylates of acetic acid and myristic acid were investigated using Atomic Absorption Spectroscopy (AAS), flame photometry, FTIR spectrophotometer and UV- Visible spectrophotometry. AAS and flame photometric results showed elemental abundance of the sodium metals in the carboxylate complexes. FTIR spectra data revealed ʋCOO- absorptions at 1636 cm-1 and 1558 cm-1 for sodium acetate and sodium myristate respectively. The free acid ligands showed absorptions at 1703 cm-1 for acetic acid which shifted to 1636 cm-1 for sodium acetate. FTIR absorption of myristic acid revealed a strong absorption band at 1696 cm-1 which shifted to 1558 cm-1 in sodium myristate. The geometry of the complexes were determined by the magnitude of separation, Δʋ, which is equal to ʋaym - ʋsym,. The values of Δʋ for the synthesized sodium acetate complex was found to be 231 cm-1 and 138 cm-1 for sodium myristate indicating monodentate and bridging bidentate bonding respectively. Force constants of the carboxylates which correspond to their bond energies were found to be 1495.94 K NM-1 and 1358 K NM-1 for sodium acetate and sodium myristate, respectively. The UV- Visible analysis shows ʎ max values of 201 nm and 195 nm for sodium acetate and sodium myristate respectively, which corresponds to the absorption of the COO chromophore which is due to n-π* transition.
虽然金属羧酸盐并不罕见或难以获得，但除了醋酸盐之外，完整的表征在很大程度上被忽视了，因此羧酸盐文献的不足导致了现有表征数据的差异。因此，使用原子吸收光谱法(AAS)，火焰光度法，红外分光光度计和紫外可见分光光度计。原子吸收光谱和火焰光度测定结果表明，羧酸盐配合物中金属钠元素丰度较高。FTIR光谱数据显示，乙酸钠和肉豆蔻酸钠的吸光度分别为1636 cm-1和1558 cm-1。游离酸配体对乙酸的吸光度为1703 cm-1，对乙酸钠的吸光度为1636 cm-1。肉豆蔻酸在1696 cm-1处有较强的吸收带，肉豆蔻酸钠在1558 cm-1处有较强的吸收带。配合物的几何形状是由分离的大小决定的，Δ，等于，。合成的乙酸钠配合物的Δ - k值为231 cm-1，肉豆酸钠的值为138 cm-1，分别表示单齿和桥接双齿键。乙酸钠和肉豆蔻酸钠羧酸盐的力常数分别为1495.94 K NM-1和1358 K NM-1。紫外可见光谱分析表明，乙酸钠和肉豆蔻酸钠的最大吸收波长分别为201 nm和195 nm，对应于COO发色团因n-π*跃迁而被吸收。
{"title":"Synthesis and Spectrophotometric Properties of Sodium Metal Carboxylates","authors":"Iortyom Susan Doofan, Kukwa Donald, Iornumbe Esther Nguumbur, A. Gbaa, Ijuo Godwin","doi":"10.11648/J.SJC.20210905.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20210905.11","url":null,"abstract":"While metal carboxylates are by no means rare or inaccessible, complete characterization with notable exception of acetates is largely neglected hence a deficiency within the carboxylate literature giving rise to discrepancies within the characterization data available thus, spectroscopic properties of synthesized sodium metal carboxylates of acetic acid and myristic acid were investigated using Atomic Absorption Spectroscopy (AAS), flame photometry, FTIR spectrophotometer and UV- Visible spectrophotometry. AAS and flame photometric results showed elemental abundance of the sodium metals in the carboxylate complexes. FTIR spectra data revealed ʋCOO- absorptions at 1636 cm-1 and 1558 cm-1 for sodium acetate and sodium myristate respectively. The free acid ligands showed absorptions at 1703 cm-1 for acetic acid which shifted to 1636 cm-1 for sodium acetate. FTIR absorption of myristic acid revealed a strong absorption band at 1696 cm-1 which shifted to 1558 cm-1 in sodium myristate. The geometry of the complexes were determined by the magnitude of separation, Δʋ, which is equal to ʋaym - ʋsym,. The values of Δʋ for the synthesized sodium acetate complex was found to be 231 cm-1 and 138 cm-1 for sodium myristate indicating monodentate and bridging bidentate bonding respectively. Force constants of the carboxylates which correspond to their bond energies were found to be 1495.94 K NM-1 and 1358 K NM-1 for sodium acetate and sodium myristate, respectively. The UV- Visible analysis shows ʎ max values of 201 nm and 195 nm for sodium acetate and sodium myristate respectively, which corresponds to the absorption of the COO chromophore which is due to n-π* transition.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85671566","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}
Pub Date : 2021-08-31DOI: 10.11648/j.sjc.20210904.13
Minghui Jiang, M. Hang, Yubing Yang, Teng-fei Cheng, Hao Wang, Gang Zhou
Reinforced concrete structures are easily corroded in the Salt Lake areas of China, especially in harsh environmental circumstance, such as freezing-thawing cycles, wetting-dry, et al, thus causing a lot of damage problems (concrete deterioration and steel bars corrosion). This research investigation was a research study which was to solve the corrosion problem of reinforced concrete structures under the chloride environmental circumstance through the electrochemical performance and mechanical properties test of the reinforced mortar specimens, the effect of single or compound doping of two organic and two inorganic corrosion inhibitors to the electrode potential, electrochemical impedance spectroscopy and mechanical properties of the reinforced mortar were investigated. The experimental conclusion demonstrated that the organic or inorganic corrosion inhibitors after single and compound doping showed some degree influence on the electrode potential and mechanical properties of the reinforced mortar specimens. Meanwhile, when the ratio of triethanolamine (TEA):triisopropanolamine (TIPA) was 7:3, sodium monofluorophosphate (MFP):sodium molybdate was 5:5, the compressive strength and flexural strength of mortar after curing for 28 days were greater than 90%, it indicated that these proportions showed the best corrosion resistance performance of steel bars. Therefore, these proportions of corrosion inhibitors could be used in reinforced concrete structures. The significant was that these results could provide theoretical guidance and technical basis for the study of corrosion damage of reinforced concrete structures in the future.
{"title":"Inhibition Effect of Different Corrosion Inhibitors on Steel Bars Corrosion and Improvement Effect After Double Doped","authors":"Minghui Jiang, M. Hang, Yubing Yang, Teng-fei Cheng, Hao Wang, Gang Zhou","doi":"10.11648/j.sjc.20210904.13","DOIUrl":"https://doi.org/10.11648/j.sjc.20210904.13","url":null,"abstract":"Reinforced concrete structures are easily corroded in the Salt Lake areas of China, especially in harsh environmental circumstance, such as freezing-thawing cycles, wetting-dry, et al, thus causing a lot of damage problems (concrete deterioration and steel bars corrosion). This research investigation was a research study which was to solve the corrosion problem of reinforced concrete structures under the chloride environmental circumstance through the electrochemical performance and mechanical properties test of the reinforced mortar specimens, the effect of single or compound doping of two organic and two inorganic corrosion inhibitors to the electrode potential, electrochemical impedance spectroscopy and mechanical properties of the reinforced mortar were investigated. The experimental conclusion demonstrated that the organic or inorganic corrosion inhibitors after single and compound doping showed some degree influence on the electrode potential and mechanical properties of the reinforced mortar specimens. Meanwhile, when the ratio of triethanolamine (TEA):triisopropanolamine (TIPA) was 7:3, sodium monofluorophosphate (MFP):sodium molybdate was 5:5, the compressive strength and flexural strength of mortar after curing for 28 days were greater than 90%, it indicated that these proportions showed the best corrosion resistance performance of steel bars. Therefore, these proportions of corrosion inhibitors could be used in reinforced concrete structures. The significant was that these results could provide theoretical guidance and technical basis for the study of corrosion damage of reinforced concrete structures in the future.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72949314","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}
Pub Date : 2021-07-29DOI: 10.11648/J.SJC.20210904.11
Mahnaz Jabbarzadeh Sani
Herein we report the density functional theory (DFT) calculations of nonlinear optical (NLO) properties of neutral gold clusters Aun (n=2-10) applying long-range corrected LC-M06L functional and Los-Alamos National Laboratory double-ζ polarized basis set. The effects of the incident frequency on the first and second-order hyperpolarizability together with the influence of the external electric field on the frontier orbitals of neutral gold clusters are investigated. It is found that the application of external electric field can increase or decrease the gap energy of neutral gold clusters depending on the direction and magnitude of the applied field. More importantly, by correctly controlling the direction and magnitude of the external electric field, reactive gold clusters having low gap energies can be achieved. Furthermore, the external electric field has more important effect on the virtual orbitals of gold hexamer and decreases the energy of these orbitals along the directions parallel to the molecular plane, resulting in low-energy excitations. The low-energy excitations are expected to play important role in the high second-order hyperpolarizability and better response to the applied field. The third-order nonlinear (NLO) properties of gold hexamer are also strongly affected by the frequency of the incident light and thus can be tuned using the incident frequency for applications. The present work may propose new strategies for enhancing the nonlinear optical response of neutral gold clusters.
{"title":"Electric Field Effects on Neutral Gold Clusters Au2-10: A First-Principles Theoretical Survey of the First- and Second-Order Hyperpolarizabilities","authors":"Mahnaz Jabbarzadeh Sani","doi":"10.11648/J.SJC.20210904.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20210904.11","url":null,"abstract":"Herein we report the density functional theory (DFT) calculations of nonlinear optical (NLO) properties of neutral gold clusters Aun (n=2-10) applying long-range corrected LC-M06L functional and Los-Alamos National Laboratory double-ζ polarized basis set. The effects of the incident frequency on the first and second-order hyperpolarizability together with the influence of the external electric field on the frontier orbitals of neutral gold clusters are investigated. It is found that the application of external electric field can increase or decrease the gap energy of neutral gold clusters depending on the direction and magnitude of the applied field. More importantly, by correctly controlling the direction and magnitude of the external electric field, reactive gold clusters having low gap energies can be achieved. Furthermore, the external electric field has more important effect on the virtual orbitals of gold hexamer and decreases the energy of these orbitals along the directions parallel to the molecular plane, resulting in low-energy excitations. The low-energy excitations are expected to play important role in the high second-order hyperpolarizability and better response to the applied field. The third-order nonlinear (NLO) properties of gold hexamer are also strongly affected by the frequency of the incident light and thus can be tuned using the incident frequency for applications. The present work may propose new strategies for enhancing the nonlinear optical response of neutral gold clusters.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"110 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79448449","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}
Pub Date : 2021-06-29DOI: 10.11648/J.SJC.20210903.13
B. Habila, E. C. Ezeh, S. Saidu, J. Attah, P. O. Nsude, E. Agboeze, Ikechukwu Ozoemena, J. Gaiya, Tachye Ninnat Bwankhot Shekarri, Sunday Ture Dahiru, Olajide Joseph Igbehinadun
Polysiloxanes are characterized by silicon and oxygen backbone and are hydrophobic in nature with low moisture uptake widely used for medical applications. Polysiloxane immobilized thiosalicylic acid ligand system has been prepared through sol-gel method, gelation was observed after 40 minutes. The immobilized ligand was characterized using FTIR, the spectrum showed characteristic absorption bands (cm-1) at: 3377 (OH), 2981 (C-H stretch); 2631 (SH); 1587 to 1684 (C=C, C=O); 1032 to 1144 (Si - O) respectively. SEM analysis showed irregular particle sizes of the polysiloxane matrices while EDX elemental composition gave (wt %): 3-CPPS; Si (50.45), O (25.02) and Cl (24.57). F - 3CPPS showed, O (58.68), Si (41.32); thiosalicylic (7.14 of S). The extraction of metal ions (Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+) were studied using Microwave Plasma Atomic Emission Spectrophotometer (Agilent MPAES-4200) at pH 6.0. Thermodynamic range with respect to Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+ yielded negative values forΔGo: Cu2+-(11.483 to 14.842) to Zn2+ -(14.368 to 14.842)KJmol-1; positive values for ΔHo: Fe3+ (0.000) to Pb2+ (105.130)KJmol-1 and ΔSo: Zn2+ (47.421) to Pb2+ (389.328)Jmol1K1 respectively, indicating spontaneous, endothermic reactions and high degree of disorderliness with respect to metal ion binding capacity to the ligand system.
{"title":"Immobilized Thiosalicylic Ligand System Potentials for the Detoxification of Some Heavy Metals from Tannery Wastewater","authors":"B. Habila, E. C. Ezeh, S. Saidu, J. Attah, P. O. Nsude, E. Agboeze, Ikechukwu Ozoemena, J. Gaiya, Tachye Ninnat Bwankhot Shekarri, Sunday Ture Dahiru, Olajide Joseph Igbehinadun","doi":"10.11648/J.SJC.20210903.13","DOIUrl":"https://doi.org/10.11648/J.SJC.20210903.13","url":null,"abstract":"Polysiloxanes are characterized by silicon and oxygen backbone and are hydrophobic in nature with low moisture uptake widely used for medical applications. Polysiloxane immobilized thiosalicylic acid ligand system has been prepared through sol-gel method, gelation was observed after 40 minutes. The immobilized ligand was characterized using FTIR, the spectrum showed characteristic absorption bands (cm-1) at: 3377 (OH), 2981 (C-H stretch); 2631 (SH); 1587 to 1684 (C=C, C=O); 1032 to 1144 (Si - O) respectively. SEM analysis showed irregular particle sizes of the polysiloxane matrices while EDX elemental composition gave (wt %): 3-CPPS; Si (50.45), O (25.02) and Cl (24.57). F - 3CPPS showed, O (58.68), Si (41.32); thiosalicylic (7.14 of S). The extraction of metal ions (Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+) were studied using Microwave Plasma Atomic Emission Spectrophotometer (Agilent MPAES-4200) at pH 6.0. Thermodynamic range with respect to Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+ yielded negative values forΔGo: Cu2+-(11.483 to 14.842) to Zn2+ -(14.368 to 14.842)KJmol-1; positive values for ΔHo: Fe3+ (0.000) to Pb2+ (105.130)KJmol-1 and ΔSo: Zn2+ (47.421) to Pb2+ (389.328)Jmol1K1 respectively, indicating spontaneous, endothermic reactions and high degree of disorderliness with respect to metal ion binding capacity to the ligand system.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84336848","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}
Pub Date : 2021-05-21DOI: 10.11648/J.SJC.20210903.12
Zhang Yun-shen
A novel green synthesis process of methyl-β-cyclodextrin was investigated through the reaction betweenβ-cyclodextrin and dimethyl carbonate in DMF (dimethyl formamide) with anhydrous potassium carbonate as catalyst. The influences of factors including reaction time and temperature, molar ratio of β-cyclodextrin to dimethyl carbonate and dosage of anhydrous potassium carbonate on the average degree of substitution of methyl-β-cyclodextrin were studied via orthogonal experiments. The results show that the average degree of methyl-β-cyclodextrin depends on the reaction temperature and the molar ratio of raw material primarily. The optimal maximum average degree of substitution of methyl-β-cyclodextrin can reach 14.2 when the molar ratio of β-cyclodextrin to dimethyl carbonate, reaction temperature, reaction time and molar ratio of β-cyclodextrin to catalyst are 1:28, 85℃, 24 h and 1:14, respectively. The structures of the synthesized methyl-β-cyclodextrin were characterized by TLC, IR, MS, 1H-NMR and 13C-NMR, respectively. All the results are concordant with those of methyl-β-cyclodextrin synthesized by dimethyl sulfate or methyl iodide. It should be pointed out that the methyl-β-cyclodextrin synthesis technology proposed is a simple and green one.
{"title":"A Novel Synthesis Technology of Ethyl-β-Cyclodextrin","authors":"Zhang Yun-shen","doi":"10.11648/J.SJC.20210903.12","DOIUrl":"https://doi.org/10.11648/J.SJC.20210903.12","url":null,"abstract":"A novel green synthesis process of methyl-β-cyclodextrin was investigated through the reaction betweenβ-cyclodextrin and dimethyl carbonate in DMF (dimethyl formamide) with anhydrous potassium carbonate as catalyst. The influences of factors including reaction time and temperature, molar ratio of β-cyclodextrin to dimethyl carbonate and dosage of anhydrous potassium carbonate on the average degree of substitution of methyl-β-cyclodextrin were studied via orthogonal experiments. The results show that the average degree of methyl-β-cyclodextrin depends on the reaction temperature and the molar ratio of raw material primarily. The optimal maximum average degree of substitution of methyl-β-cyclodextrin can reach 14.2 when the molar ratio of β-cyclodextrin to dimethyl carbonate, reaction temperature, reaction time and molar ratio of β-cyclodextrin to catalyst are 1:28, 85℃, 24 h and 1:14, respectively. The structures of the synthesized methyl-β-cyclodextrin were characterized by TLC, IR, MS, 1H-NMR and 13C-NMR, respectively. All the results are concordant with those of methyl-β-cyclodextrin synthesized by dimethyl sulfate or methyl iodide. It should be pointed out that the methyl-β-cyclodextrin synthesis technology proposed is a simple and green one.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78134824","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}
Pub Date : 2021-05-14DOI: 10.11648/J.SJC.20210903.11
Lin Zhong
The Discrete Element Method (DEM) is a calculation method by which a particle flow at a single particle occurs. It is widely used in many fields such as coastal engineering, mining and civil engineering. Specifically, when small particles are taken away by water, pores will increase and collapse due to the soil's own weight, which will cause other parts of the soil to deform. Due to the continuous development of piping, small soil particles are taken away from the entrance, so the entrance is constantly expanding. Once the upper layer of soil loses the support below, the upper layer of particles will collapse under infiltration. Therefore, as the above phenomenon continues to develop, the amount and flow of water will increase. At the same time, this will increase the rate of seepage destruction. In fact, the law of particle motion includes the growth, aggregation, diffusion and crystallization of particles under different conditions, which can be applied to other fields, such as the research of material surface roughness in textile science, the crystal origin and potential self-rotation in electronic engineering, etc. The research of this paper can provide a further theoretical basis and framework for the above direction, and pave the way for the majority of scholars to carry out the follow-up research work. In this article, EDEM (Electronic Discrete Element Method) modeling is used to simulate the movement of particles during the slip.
{"title":"DEM Modelling of Particle Movement During Seepage Failure","authors":"Lin Zhong","doi":"10.11648/J.SJC.20210903.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20210903.11","url":null,"abstract":"The Discrete Element Method (DEM) is a calculation method by which a particle flow at a single particle occurs. It is widely used in many fields such as coastal engineering, mining and civil engineering. Specifically, when small particles are taken away by water, pores will increase and collapse due to the soil's own weight, which will cause other parts of the soil to deform. Due to the continuous development of piping, small soil particles are taken away from the entrance, so the entrance is constantly expanding. Once the upper layer of soil loses the support below, the upper layer of particles will collapse under infiltration. Therefore, as the above phenomenon continues to develop, the amount and flow of water will increase. At the same time, this will increase the rate of seepage destruction. In fact, the law of particle motion includes the growth, aggregation, diffusion and crystallization of particles under different conditions, which can be applied to other fields, such as the research of material surface roughness in textile science, the crystal origin and potential self-rotation in electronic engineering, etc. The research of this paper can provide a further theoretical basis and framework for the above direction, and pave the way for the majority of scholars to carry out the follow-up research work. In this article, EDEM (Electronic Discrete Element Method) modeling is used to simulate the movement of particles during the slip.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88461346","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}
Pub Date : 2021-04-23DOI: 10.11648/J.SJC.20210902.12
Odum Bismark, Owusu Kwaku Michael, Odoom Kwesi Justice, E. Otoo, Norgbey Eyram, Kwakye Danso Benjamin
The use of acid hydrolysis to convert starch into dextrose can be difficult and time-consuming. The process requires high acidic medium and temperature which tends to contaminate the end-product hydrolysate. Therefore, this research was carried out to obtain optimum conditions necessary to produce a high and quality Dextrose Equivalent by varying the initial starch concentration and acid volume. The mass of corn and cassava starch and the total hydrochloric acid volume used for the hydrolysis ranged from 100 to 400 g and 1-3 liters respectively. The results showed that the optimum conditions for hydrolyzing the two starch types to Dextrose were within a temperature range of 100°C-120°C, 12 w/w% starch concentration, 4 atmospheric pressure and 30 minutes operating time. The optimum conditions produced a Dextrose Equivalent of 79.80% and 78.66% for cassava and corn starch respectively. The amount of dextrose produced in the process is a function of temperature, pressure, acid volume, operating time and initial starch concentration. Experimental results also confirmed an increase in pH of the hydrolysate with a temperature rise, and this influenced the Dextrose quality. The outcomes provided new findings to complement existing outcomes on how initial starch concentration and acid volume affect Dextrose Equivalent by acid-type hydrolysis.
{"title":"Dextrose Equivalent Analysis of Acid Hydrolysed Corn and Cassava Starch Sourced from Ghana","authors":"Odum Bismark, Owusu Kwaku Michael, Odoom Kwesi Justice, E. Otoo, Norgbey Eyram, Kwakye Danso Benjamin","doi":"10.11648/J.SJC.20210902.12","DOIUrl":"https://doi.org/10.11648/J.SJC.20210902.12","url":null,"abstract":"The use of acid hydrolysis to convert starch into dextrose can be difficult and time-consuming. The process requires high acidic medium and temperature which tends to contaminate the end-product hydrolysate. Therefore, this research was carried out to obtain optimum conditions necessary to produce a high and quality Dextrose Equivalent by varying the initial starch concentration and acid volume. The mass of corn and cassava starch and the total hydrochloric acid volume used for the hydrolysis ranged from 100 to 400 g and 1-3 liters respectively. The results showed that the optimum conditions for hydrolyzing the two starch types to Dextrose were within a temperature range of 100°C-120°C, 12 w/w% starch concentration, 4 atmospheric pressure and 30 minutes operating time. The optimum conditions produced a Dextrose Equivalent of 79.80% and 78.66% for cassava and corn starch respectively. The amount of dextrose produced in the process is a function of temperature, pressure, acid volume, operating time and initial starch concentration. Experimental results also confirmed an increase in pH of the hydrolysate with a temperature rise, and this influenced the Dextrose quality. The outcomes provided new findings to complement existing outcomes on how initial starch concentration and acid volume affect Dextrose Equivalent by acid-type hydrolysis.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76914168","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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