Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal...Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal of free fatty acids(FFAs)in deteriorated vegetable oil.Ni Fe2 O4 was characterized using Fourier transformed infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermogravimetric(TG)analysis,Brunauer–Emm ett–Teller(BET)surface area,transmission electron microscopy(TEM),scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDX).Synthesis of Ni Fe_(2)_(O4)was confirmed by characterization,which revealed a BET surface area of 16.30 m^(2)·g^(-1)and crystallite size of 29 nm.Ni Fe_(2)_(O4)exhibited an adsorption capacity of 145.20 L·kg^(-1)towards FFAs with an 80.69%removal in a process,which obeys Langmuir isotherm and can be described by the pseudo-second-order kinetic model.The process has enthalpy(DH)of 11.251 k Jámolà1 and entropy(DS)of 0.038 k J·mol^(-1)K^(-1)with negative free energy change(DG),which suggests the process to be spontaneous and endothermic.The quantum chemical computation analysis via density functional theory further revealed the sorption mechanism of FFAs by Ni Fe_(2)_(O4)occurred via donor–acceptor interaction,which may be described by the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO).The study showed Ni Fe_(2)_(O4)to be a potential means that can remove FFAs from deteriorated vegetable oil.展开更多
This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are ca...This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are cast; each specimen has two different strengths,the lower strength in the middle segment and higher strength in both ends. The lower strength is to simulate the status of partial deteriorated region. Different layers of CFRP sheets have been wrapped just on the lower strength part to gain the reinforcement with CFRP sheets,and to verify the practicability of partial confinement. Specimens are subjected to monotonic axial compression until failure. Axial load,axial and transverse strains are measured to compare the different behaviors between the two parts. Experimental results show that partial confinement can significantly enhance the strength and the ductility of the deteriorated strength part,then,the load capacity of the whole column can be increased subsequently. Test data indicate that the ultimate load of the confined column is higher than that of the original column without deterioration; partial confinement on weakness is a feasible approach.展开更多
This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal ...This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal policy of this inventory problem by analyzing the structural properties of the model, and introduce a simple algorithm for generating the optimal solution to this problem. Numerical results are reported to show effi-cacy of the proposed method.展开更多
三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定...三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定性影响。研究表明:目前三峡库区巫山段的近水平层状危岩岸坡消落带岩体劣化严重,在不同消落带劣化区存在紧密层状、松散碎裂状、溶蚀凹腔状、含挤压碎裂带等典型消落带劣化区形态;含有第1种消落带劣化区形态的危岩岸坡稳定性较好,危岩体位移较小,失稳模式为滑移破坏;含有第2种消落带劣化区形态的危岩岸坡危岩体先向坡内偏移,其后随着消落带岩体支撑强度弱化向坡外倾倒破坏;含有第3种消落带劣化区形态的危岩岸坡危岩体向坡外位移较大,失稳模式为倾倒破坏;含有第4种消落带劣化区形态的危岩岸坡稳定性主要受挤压破碎带的力学性质控制,易产生沿破碎带切割面的旋转滑移破坏;通过对以上4种劣化区形态的危岩岸坡增加防治加固措施,危岩体的变形位移得到了不同程度的有效控制。展开更多
文摘Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal of free fatty acids(FFAs)in deteriorated vegetable oil.Ni Fe2 O4 was characterized using Fourier transformed infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermogravimetric(TG)analysis,Brunauer–Emm ett–Teller(BET)surface area,transmission electron microscopy(TEM),scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDX).Synthesis of Ni Fe_(2)_(O4)was confirmed by characterization,which revealed a BET surface area of 16.30 m^(2)·g^(-1)and crystallite size of 29 nm.Ni Fe_(2)_(O4)exhibited an adsorption capacity of 145.20 L·kg^(-1)towards FFAs with an 80.69%removal in a process,which obeys Langmuir isotherm and can be described by the pseudo-second-order kinetic model.The process has enthalpy(DH)of 11.251 k Jámolà1 and entropy(DS)of 0.038 k J·mol^(-1)K^(-1)with negative free energy change(DG),which suggests the process to be spontaneous and endothermic.The quantum chemical computation analysis via density functional theory further revealed the sorption mechanism of FFAs by Ni Fe_(2)_(O4)occurred via donor–acceptor interaction,which may be described by the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO).The study showed Ni Fe_(2)_(O4)to be a potential means that can remove FFAs from deteriorated vegetable oil.
文摘This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are cast; each specimen has two different strengths,the lower strength in the middle segment and higher strength in both ends. The lower strength is to simulate the status of partial deteriorated region. Different layers of CFRP sheets have been wrapped just on the lower strength part to gain the reinforcement with CFRP sheets,and to verify the practicability of partial confinement. Specimens are subjected to monotonic axial compression until failure. Axial load,axial and transverse strains are measured to compare the different behaviors between the two parts. Experimental results show that partial confinement can significantly enhance the strength and the ductility of the deteriorated strength part,then,the load capacity of the whole column can be increased subsequently. Test data indicate that the ultimate load of the confined column is higher than that of the original column without deterioration; partial confinement on weakness is a feasible approach.
文摘This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal policy of this inventory problem by analyzing the structural properties of the model, and introduce a simple algorithm for generating the optimal solution to this problem. Numerical results are reported to show effi-cacy of the proposed method.
文摘三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定性影响。研究表明:目前三峡库区巫山段的近水平层状危岩岸坡消落带岩体劣化严重,在不同消落带劣化区存在紧密层状、松散碎裂状、溶蚀凹腔状、含挤压碎裂带等典型消落带劣化区形态;含有第1种消落带劣化区形态的危岩岸坡稳定性较好,危岩体位移较小,失稳模式为滑移破坏;含有第2种消落带劣化区形态的危岩岸坡危岩体先向坡内偏移,其后随着消落带岩体支撑强度弱化向坡外倾倒破坏;含有第3种消落带劣化区形态的危岩岸坡危岩体向坡外位移较大,失稳模式为倾倒破坏;含有第4种消落带劣化区形态的危岩岸坡稳定性主要受挤压破碎带的力学性质控制,易产生沿破碎带切割面的旋转滑移破坏;通过对以上4种劣化区形态的危岩岸坡增加防治加固措施,危岩体的变形位移得到了不同程度的有效控制。
