Boost converter design for ferrite core compatible with strong magnetic fields

Bing Bai,Xuesong Zhou 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2

Boost converters with a ferrite core are widely used in neurostimulators. However, there may be some problems if it is used in a strong magnetic field because the saturation of the ferrite core leads to a serious decline in the inductance value. To evaluate whether a converter can work normally in a strong magnetic field, it is critical to obtain the lower limit value of the inductance of the converter. Besides, small inductance is easy to fit the small volume of a converter and is also safe in some special scenarios. Therefore, this paper is mainly devoted to establishing the minimum inductance design criterion of boost converters with a pulse load. The operational modes and equivalent circuit considering the parasitic resistance of boost converter components are presented. Then the mathematical formula for the minimal inductance value is derived through theoretical analysis of the components’ current and output voltage. A digital simulation model of a boost converter is established to verify the theoretical analysis. Sets of comparison curves between the theoretical analysis and the simulation show that their results are in good agreement verifying the feasibility of the proposed method. The results in this paper provide theoretical support for the compatibility of converters containing a ferrite core inductor in a strong magnetic field and for the design requirement of a converter with a little volume inductor.

Experimental study on the consolidation of saturated silty clay subjected to cyclic thermal loading

Bai, Bing,Shi, Xiaoying Techno-Press 2017 Geomechanics & engineering Vol.12 No.4

The objective of this paper is to experimentally study the consolidation of saturated silty clay subjected to repeated heating-cooling cycles using a modified temperature-controlled triaxial apparatus. Focus is placed on the influence of the water content, confining pressure, and magnitudes and number of thermal loading cycles. The experimental results show that the thermally induced pore pressure increases with increasing water content and magnitude of thermal loading in undrained conditions. After isothermal consolidation at an elevated temperature, the pore pressure continues to decrease and gradually falls below zero during undrained cooling, and the maximum negative pore pressure increases as the water content decreases or the magnitude of thermal loading increases. During isothermal consolidation at ambient temperature after one heating-cooling cycle, the pore pressure begins to rise due to water absorption and finally stabilizes at approximately zero. As the number of thermal loading cycles increases, the thermally induced pore pressure shows a degrading trend, which seems to be more apparent under a higher confining pressure. Overall, the specimens tested show an obvious volume reduction at the completion of a series of heating-cooling cycles, indicating a notable irreversible thermal consolidation deformation.

Power Quality Warning of High-Speed Rail Based on Multi-Features Similarity

Bai, Jingjing,Gu, Wei,Yuan, Xiaodong,Li, Qun,Chen, Bing,Wang, Xuchong The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

As one type of power quality (PQ) disturbance sources, high-speed rail (HSR) can have major impacts on the power supply grid. Providing timely and accurate warning information for PQ problems of HSR is important for the safe and stable operation of traction power supply systems and the power supply grid. This study proposes a novel warning approach to identify PQ problems and provide warning prompts based on the monitored data of HSR. To embody the displacement and status change of monitored data, multi-features of different sliding windows are computed. To reflect the relative importance degree of these features in the overall evaluation, an analytic hierarchy process (AHP) is used to analyse the weights of multi-features. Finally, a multi-features similarity algorithm is applied to analyse the difference between monitored data and the reference data of HSR, and PQ warning results based on dynamic thresholds can be analysed to quantify its severity. Cases studies demonstrate that the proposed approach is effective and feasible, and it has now been applied to an actual PQ monitoring platform.

Systemic administration of low dosage of tetanus toxin decreases cell proliferation and neuroblast differentiation in the mouse hippocampal dentate gyrus

Bing Chun Yan,In Hye Kim,Joon Ha Park,Ji Hyeon Ahn,Jeong-Hwi Cho,Bai Hui Chen,Jae-Chul Lee,Jung Hoon Choi,Ki-Yeon Yoo,Choong Hyun Lee,Jun Hwi Cho,Jong-Dai Kim,Moo-Ho Won 한국실험동물학회 2013 Laboratory Animal Research Vol.29 No.3

In the present study, we investigated the effect of Tetaus toxin (TeT) on cell proliferation and neuroblast differentiation using specific markers: 5-bromo-2-deoxyuridine (BrdU) as an exogenous marker for cell proliferation, Ki-67 as an endogenous marker for cell proliferation and doublecortin (DCX) as a marker for neuroblasts in the mouse hippocampal dentate gyrus (DG) after TeT treatment. Mice were intraperitoneally administered 2.5 and 10 ng/kg TeT and sacrificed 15 days after the treatment. In both the TeT-treated groups, no neuronal death occurred in any layers of the DG using neuronal nuclei (NeuN, a neuron nuclei maker) and Fluoro-Jade B (F-J B, a high-affinity fluorescent marker for the localization of neuronal degeneration). In addition, no significant change in glial activation in both the 2.5 and 10 ng/kg TeT-treated-groups was found by GFAP (a marker for astrocytes) and Iba-1 (a marker for microglia) immunohistochemistry. However, in the 2.5 ng/kg TeT-treated-group, the mean number of BrdU, Ki-67 and DCX immunoreactive cells, respectively, were apparently decreased compared to the control group, and the mean number of each in the 10 ng/kg TeT-treated-group was much more decreased. In addition, processes of DCX-immunoreactive cells, which projected into the molecular layer, were short compared to those in the control group. In brief, our present results show that low dosage (10 ng/kg) TeT treatment apparently decreased cell proliferation and neuroblast differentiation in the mouse hippocampal DG without distinct gliosis as well as any loss of adult neurons.

The Research of the Oil Drilling Materials Information Management System Based on RFID

Bai Kai,Xia Hong-Nan,Jin Guo-Xing,Wang Hua-Bing 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.10

In the present drilling materials supplies management informationization level is low, which lead to low efficiency of management in the Chinese oil enterprises. This paper presents an effective solution combined with RFID and web technology for oil enterprise information service platform system, and studies several key technologies in the design. The system has taken the advantages of RFID and web services in the practical application process, the enterprises can use this RFID solution to enhance the logistics management efficiency in the oil-drilling materials supplies. At the end of the paper we proposed technical barriers is one of the reasons for RFID popularization.

Predictive Role of GSTs on the Prognosis of Breast Cancer Patients with Neoadjuvant Chemotherapy

Bai, Yun-Lu,Zhou, Bing,Jing, Xiao-Yue,Zhang, Bin,Huo, Xiao-Qing,Ma, Chao,He, Jian-Miao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Objective: To evaluate the predictive value of GST gene polymorphisms with regard to prognosis of breast cancer patients receiving neoadjuvant chemotherapy. Methods: A total of 159 patients were included in our study between January 2005 and January 2007. All the patients were followed up until January 2012. Genotyping was based upon the duplex polymerase-chain-reaction with the PCR-CTPP method. Results: Patients with null GSTM1 and GSTP1 Val/Val genotypes had significantly had better response rates to chemotherapy when compared with non-null GSTM1 and GSTP1 Ile/Ile genotypes (OR=1.96 and OR=2.14, respectively). Patients with the GSTM1 null genotype had a longer average survival time and significantly lower risk of death than did those with non-null genotypes (HR=0.66). Similarly, those carrying the GSTP1 Val/Val genotype had 0.54-fold the risk of death of those with GSTP1 Ile/Ile (HR=0.54). Conclusion: A significant association was found between GSTM1 and GSTP1 gene polymorphisms and clinical outcomes in breast cancer cases.

Melatonin improves vascular cognitive impairment induced by ischemic stroke by remyelination via activation of ERK1/2 signaling and restoration of glutamatergic synapses in the gerbil hippocampus

Chen, Bai Hui,Park, Joon Ha,Lee, Yun Lyul,Kang, Il Jun,Kim, Dae Won,Hwang, In Koo,Lee, Choong-Hyun,Yan, Bing Chun,Kim, Young-Myeong,Lee, Tae-Kyeong,Lee, Jae Chul,Won, Moo-Ho,Ahn, Ji Hyeon Elsevier 2018 BIOMEDICINE AND PHARMACOTHERAPY Vol.108 No.-

<P><B>Abstract</B></P> <P>Vascular dementia affects cognition by damaging axons and myelin. Melatonin is pharmacologically associated with various neurological disorders. In this study, effects of melatonin on cognitive impairment and related mechanisms were investigated in an animal model of ischemic vascular dementia (IVD). Melatonin was intraperitoneally administered to adult gerbils after transient global cerebral ischemia (tGCI) for 25 days beginning 5 days after tGCI. Cognitive impairment was examined using a passive avoidance test and the Barnes maze test. To investigate mechanisms of restorative effects by melatonin, neuronal damage/death, myelin basic protein (MBP, a marker for myelin), Rip (a marker for oligodendrocyte), extracellular signal-regulated protein kinase1/2 (ERK1/2) and phospho-ERK1/2 (p-ERK1/2), and vesicular glutamate transporter (VGLUT)-1 (a glutamatergic synaptic marker) in the hippocampal Cornu Ammonis 1 area (CA1) were evaluated using immunohistochemistry. Melatonin treatment significantly improved tGCI-induced cognitive impairment. Death of CA1 pyramidal neurons after tGCI was not affected by melatonin treatment. However, melatonin treatment significantly increased MBP immunoreactivity and numbers of Rip-immunoreactive oligodendrocytes in the ischemic CA1. In addition, melatonin treatment significantly increased ERK1/2 and p-ERK1/2 immunoreactivities in oligodendrocytes in the ischemic CA1. Furthermore, melatonin treatment significantly increased VGLUT-1 immunoreactive structures in the ischemic CA1. These results indicate that long-term melatonin treatment after tGCI improves cognitive deficit <I>via</I> restoration of myelin, increase of oligodendrocytes which is closely related to the activation of ERK1/2 signaling, and increase of glutamatergic synapses in the ischemic brain area.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Melatonin (Mel) improved impaired memory function after ischemia. </LI> <LI> Mel did not protect ischemia-induced (i-i) neuronal loss in the hippocampus. </LI> <LI> Mel recovered i-i damaged myelinated nerve fibers and oligodendrocytes. </LI> <LI> Mel increased ERK1/2 and p-ERK1/2 in oligodendrocytes in i-i hippocampus. </LI> <LI> Mel increased i-i damaged VGLUT-1 in the hippocampus. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Increased cyclooxygenase-2 and nuclear factor-κB/p65 expression in mouse hippocampi after systemic administration of tetanus toxin

YAN, BING CHUN,JEON, YONG HWAN,PARK, JOON HA,KIM, IN HYE,CHO, JEONG-HWI,AHN, JI HYEON,CHEN, BAI HUI,TAE, HYUN-JIN,LEE, JAE-CHUL,AHN, JI YUN,KIM, DONG WON,CHO, JUN HWI,WON, MOO-HO,HONG, SEONGKWEON SPANDIDOS PUBLICATIONS 2015 MOLECULAR MEDICINE REPORTS Vol.12 No.6

<P>Brain inflammation has a crucial role in various diseases of the central nervous system. The hippocampus in the mammalian brain exerts an important memory function, which is sensitive to various insults, including inflammation induced by exo/endotoxin stimuli. Tetanus toxin (TeT) is an exotoxin with the capacity for neuronal binding and internalization. The present study investigated changes in inflammatory mediators in the mouse hippocampus proper (CA1-3 regions) and dentate gyrus (DG) after TeT treatment. The experimental mice were intraperitoneally injected with TeT at a low dosage (100 ng/kg), while the control mice were injected with the same volume of saline. At 6, 12 and 24 h after TeT treatment, changes in the hippocampal levels of inflammatory mediators cyclooxygenase-2 (COX-2) and nuclear factor kappa-B (NF-κB/p65) were assessed using immunohistochemical and western blot analysis. In the control group, moderate COX-2 immunoreactivity was observed in the stratum pyramidal (SP) of the CA2-3 region, while almost no expression was identified in the CA1 region and the DG. COX-2 immunoreactivity was increased by TeT in the SP and granule cell layer (GCL) of the DG in a time-dependent manner. At 24 h post-treatment, COX-2 immunoreactivity in the SP of the CA1 region and in the GCL of the DG was high, and COX-2 immunoreactivity in the SP of the CA2/3 region was highest. Furthermore, the present study observed that NF-κB/p65 immunoreactivity was obviously increased in the SP and GCL at 6, 12 and 24 h after TeT treatment. In conclusion, the present study demonstrated that systemic treatment with TeT significantly increased the expression of COX-2 and NF-κB/p65 in the mouse hippo-campus, suggesting that increased COX-2 and NF-κB/65 expression may be associated with inflammation in the brain induced by exotoxins.</P>

Ethanol extract of <i>Oenanthe javanica</i> increases cell proliferation and neuroblast differentiation in the adolescent rat dentate gyrus

Chen, Bai Hui,Park, Joon Ha,Cho, Jeong Hwi,Kim, In Hye,Shin, Bich Na,Ahn, Ji Hyeon,Hwang, Seok Joon,Yan, Bing Chun,Tae, Hyun Jin,Lee, Jae Chul,Bae, Eun Joo,Lee, Yun Lyul,Kim, Jong Dai,Won, Moo-Ho,Kang Medknow PublicationsMedia Pvt Ltd 2015 Neural regeneration research Vol.10 No.2

<P><I>Oenanthe javanica</I> is an aquatic perennial herb that belongs to the <I>Oenanthe genus</I> in Apiaceae family, and it displays well-known medicinal properties such as protective effects against glutamate-induced neurotoxicity. However, few studies regarding effects of <I>Oenanthe javanica</I> on neurogenesis in the brain have been reported. In this study, we examined the effects of a normal diet and a diet containing ethanol extract of <I>Oenanthe javanica</I> on cell proliferation and neuroblast differentiation in the subgranular zone of the hippocampal dentate gyrus of adolescent rats using Ki-67 (an endogenous marker for cell proliferation) and doublecortin (a marker for neuroblast). Our results showed that <I>Oenanthe javanica</I> extract significantly increased the number of Ki-67-immunoreactive cells and doublecortin-immunoreactive neuroblasts in the subgranular zone of the dentate gyrus in the adolescent rats. In addition, the immunoreactivity of brain-derived neurotrophic factor was significantly increased in the dentate gyrus of the <I>Oenanthe javanica</I> extract-treated group compared with the control group. However, we did not find that vascular endothelial growth factor expression was increased in the <I>Oenanthe javanica</I> extract-treated group compared with the control group. These results indicate that <I>Oenanthe javanica</I> extract improves cell proliferation and neuroblast differentiation by increasing brain-derived neurotrophic factor immunoreactivity in the rat dentate gyrus.</P>

Power Quality Warning of High-Speed Rail Based on Multi-Features Similarity

Jingjing Bai,Wei Gu,Xiaodong Yuan,Qun Li,Bing Chen,Xuchong Wang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

As one type of power quality (PQ) disturbance sources, high-speed rail (HSR) can have major impacts on the power supply grid. Providing timely and accurate warning information for PQ problems of HSR is important for the safe and stable operation of traction power supply systems and the power supply grid. This study proposes a novel warning approach to identify PQ problems and provide warning prompts based on the monitored data of HSR. To embody the displacement and status change of monitored data, multi-features of different sliding windows are computed. To reflect the relative importance degree of these features in the overall evaluation, an analytic hierarchy process (AHP) is used to analyse the weights of multi-features. Finally, a multi-features similarity algorithm is applied to analyse the difference between monitored data and the reference data of HSR, and PQ warning results based on dynamic thresholds can be analysed to quantify its severity. Cases studies demonstrate that the proposed approach is effective and feasible, and it has now been applied to an actual PQ monitoring platform.