Identification of impact forces on composite structures using an inverse approach

Hu, Ning,Matsumoto, Satoshi,Nishi, Ryu,Fukunaga, Hisao Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.27 No.4

In this paper, an identification method of impact force is proposed for composite structures. In this method, the relation between force histories and strain responses is first formulated. The transfer matrix, which relates the strain responses of sensors and impact force information, is constructed from the finite element method (FEM). Based on this relation, an optimization model to minimize the difference between the measured strain responses and numerically evaluated strain responses is built up to obtain the impact force history. The identification of force history is performed by a modified least-squares method that imposes the penalty on the first-order derivative of the force history. Moreover, from the relation of strain responses and force history, an error vector indicating the force location is defined and used for the force location identification. The above theory has also been extended into the cases when using acceleration information instead of strain information. The validity of the present method has been verified through two experimental examples. The obtained results demonstrate that the present approach works very well, even when the internal damages in composites happen due to impact events. Moreover, this method can be used for the real-time health monitoring of composite structures.

Synthesis, Characterization, and Catalytic Performance of Sb₂Se₃ Nanorods

Hu, Ning,Cheney, Marcos A.,Hanifehpour, Younes,Joo, Sang Woo,Min, Bong-Ki Hindawi Limited 2017 Journal of nanomaterials Vol.2017 No.-

<P>Antimony selenide has many potential applications in thermoelectric, photovoltaic, and phase-change memory devices. A novel method is described for the rapid and scalable preparation of antimony selenide (Sb2Se3) nanorods in the presence of hydrazine hydrate and/or permanganate at 40°C. Crystalline nanorods are obtained by the addition of hydrazine hydrate in a reaction mixture of antimony acetate and/or chloride and sodium selenite in neutral and basic media, while amorphous nanoparticles are formed by the addition of KMnO4 in a reaction mixture of antimony acetate/chloride and sodium selenite. The powder X-ray diffraction pattern confirms orthorhombic phase crystalline Sb2Se3 for the first and second reactions with lattice parameters a=1.120 nm, b=1.128 nm, and c=0.383 nm and amorphous Sb2Se3 for the third reaction. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM) images show the diameter of nanorods for the first and second reactions to be in the order of 100 nm to 150 nm and about 20 nm particles for the third reaction. EDX and XPS suggest that the nanorods are pure Sb2Se3. The UV-vis analysis indicates a band gap of 4.14 and 4.97 eV for the crystalline and amorphous Sb2Se3, respectively, corresponding to a blue shift. The photocatalytic study shows that the decolorization of Rhodamine in solution by nanoparticles is slightly greater than nanorods.</P>

Modeling, Testing and Numerical Simulation on Hot Forming of HSS

Ning Ma Ping Hu,Guozhe Shen Wenhua Wu 한국소성가공학회 2010 기타자료 Vol.2010 No.6

The thermal-mechanical-transformation coupled relationship of microalloy steel has important significance in forming mechanism and numerical simulation of hot forming. Tensile and quenching experiments are implemented at high temperature, and then the thermal-mechanical-transformation coupled constitutive models of hot forming are developed. Based these models, the nonlinear large-deformation dynamic explicit finite element equations are proposed. The phase transformation latent heat is introduced into the analysis of temperature field during the hot forming process. Based on the independently developed commercial CAE software for sheet metal forming, named KMAS (King-Mesh Analysis System), the numerical simulation module of hot forming is developed, which considers multi-field coupled models, nonlinear and large deformation analysis. Then the hot forming process of a reinforced beam inside the automobile door is simulated by the KMAS software, and compared with its hot forming experimental testing. The experimental results indicate the validity and efficiency of the present multi-field coupled constitutive models and numerical simulation software KMAS of hot forming.

Synthesis and Characterization of KTiNbO5 Nano-particles by Novel Polymerizable Complex Method

Ning-ning Wang,Yun-xiang Lan,Jie He,Rui Dong,Jin-song Hu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

The layered KTiNbO5 was successfully synthesized with titanium(IV) isopropoxide and niobium oxalate by a novel polymerized complex (PC) method. The morphology and structure of the as-prepared sample was characterized by means of High-Resolution Transmission Electron Microscope, powder X-ray diffraction, and Laser Raman Spectroscopy. The spectral response characteristic was recorded by using UV-vis Diffuse Reflectance Spectroscopy. Results show that KTiNbO5 as-prepared by PC method presents an uniform morphology of nano-particles, the mean particle sizes is ca. 28 nm corresponding to the (002), and the crystal structure can be well indexed to the orthorhombic phase. The sample as-prepared by PC method has higher band gap energy than that of the sample prepared by a solid-state reaction method due to the quantum size effect.

Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression Surgery in Severe Lumbar Stenosis Under Electrophysiological MonitoringFocused on Full-Visualized Trephine/ Osteotome

Ning-Ning Dou,Hao-lin Wang,Shao-Zhen Hu,Zheng-Nan Huang,Jun Zhong,Shi-Ting Li 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: Although endoscopic drill has the advantages in manipulation and hemostasis, whose low efficiency and blurred vision reduce the efficacy of lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). The present study was designed to evaluate the safety and efficacy of full-visualized trephine/osteotome in the LE-ULBD surgery for severe lumbar stenosis. Methods: Fifty-seven severe lumbar stenosis patients who underwent LE-ULBD between January 2020 to January 2023 were enrolled, who were divided into drill and visualized trephine groups. The medical records including demographics, operative duration, intraoperative electrophysiological findings, postoperative hospital stay or hospital stay, postoperative outcomes and complications were retrospectively reviewed and analyzed. Results: A total of 57 patients included 15 in drill and 42 in trephine group were enrolled in the study. There was significant difference in the pre- and postoperative visual analogue scale and Oswestry Disability Index scores in both groups (p < 0.05). The mean operative duration in the trephine group (101.05 ± 12.18 minutes) was shorter than that in the drill group (134.67 ± 9.68 minutes) (p < 0.05). There was no statistical difference between the 2 groups in electrophysiological monitoring, posthospital stays, postoperative outcomes and complications. Abnormal free-electromyography (EMG) were recorded in 2 (13.3%) and 5 patients (11.9%) in the drill and trephine group. Intraoperative somatosensory evoked potential changes occurred in 3 (20%) and 3 patients (7.1%) in the drill and trephine group and all patients recovered immediately when surgery ended. No serious complications and recurrence occurred in all the patients. Conclusion: Full-visualized trephine/osteotome has been approved to be convenient, safe and efficient in our study, which combined with translaminar inside-out technique and EMG monitoring especially free-EMG may offer a new choice in LE-ULBD surgery for lumbar stenosis patients.

Overexpressed Derlin-1 Inhibits ER Expansion in the Endothelial Cells Derived from Human Hepatic Cavernous Hemangioma

Hu, Dong,Ran, Yu-Liang,Zhong, Xing,Hu, Hai,Yu, Long,Lou, Jin-Ning,Sun, Li-Xing,Yang, Zhi-Hua Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.6

Proteins that are unfolded or misfolded in the endoplasmic reticulum (ER) must be targeted for refolding or degradation to maintain the homeostasis of the ER. Derlin-1 was reportedly implicated in the retro-translocation of misfolded proteins from the ER to the cytosol for degradation. In this report, we showed that Derlin-1 was down-regulated in the endothelial cells derived from human hepatic cavernous hemangioma (CHEC) compared with other tested cells. Electron microscopy analysis showed that ER was aberrantly enlarged in CHEC cells, but not in other tested cells. When overexpressed, Derlin-1 induced the dilated ER to return normal size. This ER dynamic was associated with the activation of unfolded protein response (UPR). In CHEC cells where Derlin-1 was down-regulated, increased expression of the immunoglobulin heavy chain-binding protein (Bip) and UPR-specific splicing of X-box DNA-binding protein 1 (XBP1) mRNA were detected, as compared with that in other tested cells, indicating that UPR was activated. After Derlin-1 overexpression, the extent of UPR activation diminished, as evidenced by decreased expression of Bip, reduced amount of the spliced form of XBP1 ($XBP1_S$), and elevated expression of the unspliced form of XBP1 ($XBP1_U$). Taken together, these findings provide another example of a single protein being able to affect ER dynamic in mammalian cells, and an insight into the possible molecular mechanism(s).

Determination of Tocopherol Contents in Refined Edible Oils Using an HPLC Method

Hu, Jiang-Ning,Zhu, Xue-Mei,Adhikari, Prakash,Li, Dan,Kim, In-Hwan,Lee, Ki-Teak The Korean Society of Food Science and Nutrition 2009 Preventive Nutrition and Food Science Vol.14 No.3

A high-performance liquid chromatography method was applied to determine the contents of tocopherols in edible oils using a LiChrosorb DIOL HPLC column and hexane fortified with 0.1% acetic acid in an isocratic mode. The validation of the method included tests for linearity, sensitivity, accuracy, precision, and recovery. All calibration curves showed good linear regression ($r^2$>0.9995) within the tested ranges. The established method offered good precision and accuracy with overall intra-day and inter-day variations of 0.94$\sim$4.27 and 1.77$\sim$ 4.88%, respectively. The tocopherol recoveries ranged from 91.44$\sim$108.90%. Subsequently, the method was successfully applied to qualitatively and quantitatively determine the total contents of $\alpha$, $\gamma$, and $\delta$-tocopherols in 12 selected refined edible oils, showing a range of 0.92 to 188.71 mg/100 g.

Ni-NTA-COATED NANOWIRE MATERIALS FOR PROTEIN ENRICHMENT AND THE APPLICATION IN A MEDICAL DEVICE USED FOR BLOOD GLUCOSE DEGRADATION

QIN HU,YING QI LIU,NING LI,CHUN CHENG,SHUIGANG XU,NING WANG,WEI QIN,BEN ZHONG TANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.3

A general and reliable method has been developed to functionalize either the iron oxide or the silicon nanowires (NWs) with nickel–nitriloacetic acid (Ni–NTA) complex, which was manufactured to manipulate His-tagged proteins and enzymes. The Ni–NTA-functionalized sea-urchin-shaped α-Fe2O3 NWs exhibit the superior protein purification efficiency and excellent stability in the form of dry powder. Application of this new nanotechnology in biomedical research field has been explored. A glucose degradation bio-matrix was made via the Ni–NTA-modified silicon NW-chips, which were conjugated with an enzyme essential to glycolysis. The glucose level in a simulated blood solution was found to be reduced from 14.4 mM to 9 mM after incubating the hexokinase I-functionalized silicon NW-chips for 12 h. These results suggest a possible way to build up a medical device using enzymes functionalized NW-chips for the removal of excess blood glucose.

Quantum Entanglement in a Graphene Sheet

Zhan-Ning Hu,Kee-Su Park,이경수 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.2

We present the quantum entanglement and the thermal entanglement in a graphene layer. The model Hamiltonian is chosen within an effective-mass approximation, including the interaction of intervalley and intravalley scattering processes. We nd that the degenerate ground state is unentangled and that the thermal concurrence decreases down to zero as the temperature increases. A new maximally entangled quantum state is observed from the excited states of the system by using a proper choice of the Hamiltonian parameters. We present the quantum entanglement and the thermal entanglement in a graphene layer. The model Hamiltonian is chosen within an effective-mass approximation, including the interaction of intervalley and intravalley scattering processes. We nd that the degenerate ground state is unentangled and that the thermal concurrence decreases down to zero as the temperature increases. A new maximally entangled quantum state is observed from the excited states of the system by using a proper choice of the Hamiltonian parameters.

Synthesis and Characterization of KTiNbO₅ Nano-particles by Novel Polymerizable Complex Method

Wang, Ning-Ning,Lan, Yun-Xiang,He, Jie,Dong, Rui,Hu, Jin-Song Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

The layered $KTiNbO_5$ was successfully synthesized with titanium(IV) isopropoxide and niobium oxalate by a novel polymerized complex (PC) method. The morphology and structure of the as-prepared sample was characterized by means of High-Resolution Transmission Electron Microscope, powder X-ray diffraction, and Laser Raman Spectroscopy. The spectral response characteristic was recorded by using UV-vis Diffuse Reflectance Spectroscopy. Results show that $KTiNbO_5$ as-prepared by PC method presents an uniform morphology of nano-particles, the mean particle sizes is ca. 28 nm corresponding to the (002), and the crystal structure can be well indexed to the orthorhombic phase. The sample as-prepared by PC method has higher band gap energy than that of the sample prepared by a solid-state reaction method due to the quantum size effect.