Control synthesis of magnetic Fe3O4–chitosan nanoparticles under UV irradiation in aqueous system

Lian-ying Zhang,Xin-jun Zhu,Han-wen Sun,Gui-rong Chi,Jun-xiao Xu,Yong-ling Sun 한국물리학회 2010 Current Applied Physics Vol.10 No.3

Novel magnetic Fe3O4–chitosan nanoparticles were synthesized via photochemical method in an emulsifier-free aqueous system at room temperature for the first time. The scanning electron microscopy (SEM)and transmission electron microscopy (TEM) results showed that the Fe3O4–chitosan nanoparticles were in regular shape with a mean diameter of 41 nm, whereas the average size in aqueous solution measured by photocorrelation spectroscopy (PCS) was 64 nm, which indicated that the nanoparticles had waterswelling properties. X-ray diffraction (XRD) patterns indicated that the Fe3O4 nanoparticles were pure Fe3O4 with a spinel structure, and the irradiation under UV light did not result in a phase change. The Fe3O4–chitosan nanoparticles were also characterized by Fourier transform infrared (FTIR) spectra, thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). Magnetic measurement revealed that the saturated magnetization (Ms) of the Fe3O4–chitosan nanoparticles reached 48.6 emu/g and the nanoparticles showed the characteristics of superparamagnetism. The stability test showed these novel nanoparticles had high magnetic stability. The PCS and TGA results indicated that the size and chitosan content of Fe3O4–chitosan nanoparticles formed was pH- and chitosan/Fe3O4 ratio-dependent,which could be used to synthesize magnetic Fe3O4–chitosan nanoparticles with different size to meet the requirements of different applications.

Effects of maternal dietary energy restriction on laying performance, embryonic development, and lipid metabolism in broilers

Sun, Hao,Chen, Zhihui,Ma, Chengzhan,Lian, Lina,Zhao, Zeyu,Niu, Shupeng,Xu, Liangmei,Sun, Jinhua Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: The objective of this study was to investigate the effects of different degrees of maternal dietary energy restriction on lipid deposition in embryonic tissues during the medium laying period (37 to 39 weeks) in Arbor Acres (AA) broiler breeders. Methods: A single factor design was adopted, and 400 AA broiler breeders (20 weeks of age) with a similar weight were randomly allocated into four groups. The birds in the control group were fed a corn-soybean meal based diet, and those in trial groups were fed diets with 80%, 70%, and 50% energy levels of the basal diet. Incubated eggs from the medium laying period were collected. Samples of developing embryos at various stages were prepared for composition analysis. Results: The embryo weight in the 80% energy group was higher than those of the other groups on embryonic day (E) 13, but at 21 E, they were significantly decreased with decreasing energy intake of the broiler breeders (p<0.05). Additionally, the levels of crude fat in tissues in the restriction groups were significantly decreased (p<0.05). The long axis and area of adipocytes in breast muscle, thigh muscle and the liver were significantly decreased (p<0.05) at 21 E in the 80%, 70%, and 50% energy groups. Conclusion: The effects of the 80% maternal dietary energy restriction energy affects egg production performance, egg quality, and nutrient deposition in egg weights, which then directly impacts on the developmental process of embryos, especially on fat utilization and deposition.

Depression and the Risk of Breast Cancer: A Meta-Analysis of Cohort Studies

Sun, Hui-Lian,Dong, Xiao-Xin,Cong, Ying-Jie,Gan, Yong,Deng, Jian,Cao, Shi-Yi,Lu, Zu-Xun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Whether depression causes increased risk of the development of breast cancer has long been debated. We conducted an updated meta-analysis of cohort studies to assess the association between depression and risk of breast cancer. Materials and Methods: Relevant literature was searched from Medline, Embase, Web of Science (up to April 2014) as well as manual searches of reference lists of selected publications. Cohort studies on the association between depression and breast cancer were included. Data abstraction and quality assessment were conducted independently by two authors. Random-effect model was used to compute the pooled risk estimate. Visual inspection of a funnel plot, Begg rank correlation test and Egger linear regression test were used to evaluate the publication bias. Results: We identified eleven cohort studies (182,241 participants, 2,353 cases) with a follow-up duration ranging from 5 to 38 years. The pooled adjusted RR was 1.13(95% CI: 0.94 to 1.36; $I^2=67.2%$, p=0.001). The association between the risk of breast cancer and depression was consistent across subgroups. Visual inspection of funnel plot and Begg's and Egger's tests indicated no evidence of publication bias. Regarding limitations, a one-time assessment of depression with no measure of duration weakens the test of hypothesis. In addition, 8 different scales were used for the measurement of depression, potentially adding to the multiple conceptual problems concerned with the definition of depression. Conclusions: Available epidemiological evidence is insufficient to support a positive association between depression and breast cancer.

ASR을 위한 개선된 이중 확산 모델(DDM)

손연방 ( Sun Lian Fang ),유일환 ( You Ilhwan ),박진우 ( Park Jinwoo ),지광습 ( Zi Goangseup ) 한국구조물진단유지관리공학회 2018 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.22 No.1

This paper presents an improved double diffusion model (DDM) for the alkali silica reaction. By this model we could simulate the diffusion process of alkali both in concrete (macro-scale) and aggregate (micro-scale). As the alkali source, either internal or outside cases can be analyzed through this model. Concrete with different size groups of aggregate distribution also can be analyzed. Numerical simulation is utilized to analyze the ion concentration both inside the concrete and aggregate at different moment of penetration.

Closed-form solution of axisymmetric deformation of prestressed Föppl-Hencky membrane under constrained deflecting

Yong-Sheng Lian,Jun-Yi Sun,Jiao Dong,Zhou-Lian Zheng,Zhi-Xin Yang 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.69 No.6

In this study, the problem of axisymmetric deformation of prestressed Föppl-Hencky membrane under constrained deflecting was analytically solved and its closed-form solution was presented. The small-rotation-angle assumption usually adopted in membrane problems was given up, and the initial stress in membrane was taken into account. Consequently, this closed-form solution has higher calculation accuracy and can be applied for a wider range in comparison with the existing approximate solution. The presented numerical examples demonstrate the validity of the closed-form solution, and show the errors of the contact radius, profile and radial stress of membrane in the existing approximate solution brought by the small-rotation-angle assumption. Moreover, the influence of the initial stress on the contact radius is also discussed based on the numerical examples.

PageRank 알고리즘 활용한 태권도 선수들의 랭킹 산정

손해련(Hai-Lian Sun),이성노(Seong-no Lee),김만근(Man-Keun Kim) 세계태권도문화학회 2023 세계태권도문화학회지 Vol.14 No.3

The purpose of this study is to apply the Olympic Kyorugi Ranking system and PageRank algorithm to the results of four world-class taekwondo competitions held from 2020 to 2023, including G20, G14, G10, and G6, to calculate the rankings. Based on the results, a comparison between the two algorithms is conducted to provide basic information for taekwondo ranking calculation methods. For the purpose of this study, information was collected from the official website of the World Taekwondo Federation. Use MS-Excel, PyCharm, and IBM SPSS (ver. 27) programs to process data. The results of this study are as follows. Firstly, using the PageRank algorithm, the gender and weight rankings of taekwondo athletes can be calculated. Secondly, using the PageRank system for ranking calculation is more suitable for considering the relative performance of players than using the Olympic Kyorugi Ranking system for ranking calculation. Thirdly, the ranking consistency calculated using the Olympic Kyorugi Ranking system and PageRank system is relatively low.

A Braking Force Distribution Strategy for Four-in-Wheel-Motor-Driven Electric Vehicles on Roads with Different Friction Coefficients

Lian Yufeng,Liu Shuaishi,Zhongbo Sun,Liu Keping,Nie Zhigen,Tian Chongwen 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4

This paper presents an active collision avoidance system based on a braking force distribution strategy for four-in-wheel-motor-driven electric vehicles (FIWMD-EVs) on roads with different friction coefficients. There are three major contributions in the proposed braking force distribution strategy. Firstly, the braking force distribution strategy based on constrained regenerative braking strength continuity (CRBSC) is further improved, and its general analytic expressions are derived. It provides the theoretical basis of braking force distribution between front and rear wheels. Secondly, the braking forces between front and rear wheels can be redistributed by considering power demand efficiency (PDE) to protect energy storage system from overcharge. Finally, the braking forces between left and right wheels can be distributed with different adhesion coefficients to adapt to complex roads. Simulations using rapid control prototyping (RCP) and hardware-in-the-loop (HIL) simulator are performed to demonstrate the effectiveness of control scheme and adaptability of the active collision avoidance system based on the proposed braking force distribution strategy on complex roads.

Influence of Cellular Fatty Acids Composition on Ethanol Tolerance in Escherichia coli

Lian Hua LUO,Pil-Soo SEO,Jeong-Woo SEO,Sun-Yeon HEO,Dae-Hyuk KIM,Chul Ho KIM 한국생물공학회 2009 한국생물공학회 학술대회 Vol.2009 No.10

Power series solution of circular membrane under uniformly distributed loads: investigation into Hencky transformation

Sun, Jun-Yi,Rong, Yang,He, Xiao-Ting,Gao, Xiao-Wei,Zheng, Zhou-Lian Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.5

In this paper, the problem of axisymmetric deformation of the circular membrane fixed at its perimeter under the action of uniformly-distributed loads was resolved by exactly using power series method, and the solution of the problem was presented. An investigation into the so-called Hencky transformation was carried out, based on the solution presented here. The results obtained here indicate that the well-known Hencky solution is, without doubt, correct, but in the published papers the statement about its derivation is incorrect, and the so-called Hencky transformation is invalid and hence may not be extended to use as a general mathematical method.

Research on an Anchor Point Lever Beam Coupling Type Tuning Fork Micro-gyroscope

Lian-min Cao,Jian-wei Li,Xian-wen Liu,Feng-yao Sun 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.6

This paper has designed an anchor point lever beam coupled tuning fork micro-gyroscope and tested its output performance. The tuning fork micro-gyro is designed to eliminate the output error caused by orthogonal coupling and in-phase-inverting coupling by structural decoupling and electrical decoupling, and can improve the anti-vibration performance and the modal optimization ability. It has derived the dynamic response working model of the non-ideal tuning fork micro-gyroscope, and optimized the structural parameters of the micro-gyroscope by simulation analysis. The microstructure processing has been realized by the SOI-MEMS process, sealed the processed structural prototype, and tested the performance through the established experimental system. According to the test results, the designed micro-gyroscope driving direction has greatly reduced the in-phase-inverting coupling through the anchor coupling lever beam, and the detection direction eff ectively suppressed the in-phase-inverting coupling through the stiff ness matching electrode. While closed-loop detecting, the measured Aallan variance zero-bias stability is 1.779°/h, and the 1σ zero-bias stability is 8.3°/h. While applying a stiff ness matching voltage, the measured vibration sensitivity is 23.9°/h/g.