Fatigue characteristics of distributed sensing cables under low cycle elongation

Dan Zhang,Jiacheng Wang,Bo li,Bin Shi 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.18 No.6

When strain sensing cables are under long-term stress and cyclic loading, creep may occur in the jacket material and each layer of the cable structure may slide relative to other layers, causing fatigue in the cables. This study proposes a device for testing the fatigue characteristics of three types of cables operating under different conditions to establish a decay model for observing the patterns of strain decay. The fatigue characteristics of cables encased in polyurethane (PU), GFRP-reinforced, and wire rope-reinforced jackets were compared. The findings are outlined as follows. The cable strain decayed exponentially, and the decay process involved quick decay, slow decay, and stabilization stages. Moreover, the strain decay increased with the initial strain and tensile frequency. The shorter the unstrained period was, the more similar the initial strain levels of the strain decay curves were to the stabilized strain levels of the first cyclic elongation. As the unstrained period increased, the initial strain levels of the strain decay curves approached those of the first cyclic elongation. The tested sensing cables differed in the amount and rate of strain decay. The wire rope-reinforced cable exhibited the smallest amount and rate of decay, whereas the GFRP-reinforced cable demonstrated the largest.

Research of Regional Forest Fire Prediction Method based on Multivariate Linear Regression

Dan Liu,Yanrong Zhang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.1

In order to achieve the predicted speed, high accuracy, the use of simple purpose, forest fire prediction of the key issues is to choose the main predictors. Forest fire prediction involves many factors, some of which are stable factors such as climate, topography, forest characteristics; and some unstable factors, such as fuel moisture content, meteorological factors, and other sources of ignition. Currently leading factor in the prediction of forest fire is often used in the fuel moisture, precipitation or dry days, relative humidity, temperature and wind five factors. In this paper, some of the data Yichun fire nearly a decade predict the forest fire meteorological data analysis, using multivariate linear regression to derive forest fire prediction method in the wireless sensor networks.

Isolation and Identification of Lactic Acid Bacteria from Traditional Dairy Products in Baotou and Bayannur of Midwestern Inner Mongolia and q-PCR Analysis of Predominant Species

Dan Wang,Wenjun Liu,Yan Ren,Liangliang De,Donglei Zhang,Yanrong Yang,Qiuhua Bao,Heping Zhang,Bilige Menghe 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.4

In this study, traditional culture method and 16S rRNA gene analysis were applied to reveal the composition and diversity of lactic acid bacteria (LAB) of fermented cow milk, huruud and urum from Baotou and Bayannur of midwestern Inner Mongolia. Also, the quantitative results of dominant LAB species in three different types of dairy products from Baotou and Bayannur were gained by quantitative polymerase chain reaction (q-PCR) technology. Two hundred and two LAB strains isolated from sixty-six samples were identified and classified into four genera, namely Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, and twenty-one species and subspecies. From these isolates, Lactococcus lactis subsp. lactis (32.18%), Lactobacillus plantarum (12.38%) and Leuconosto mesenteroides (11.39%) were considered as the dominated LAB species under the condition of cultivating in MRS and M17 medium. And the q-PCR results revealed that the number of dominant species varied from samples to samples and from region to region. This study clearly shows the composition and diversity of LAB existing in fermented cow milk, huruud and urum, which could be considered as valuable resources for LAB isolation and further probiotic selection.

Improvement of Poly(γ-glutamic acid) Biosynthesis and Quantitative Metabolic Flux Analysis of a Two-stage Strategy for Agitation Speed Control in the Culture of Bacillus subtilis NX-2

Dan Zhang,Zongqi Xu,Hong Xu,Xiaohai Feng,Sha Li,Heng Cai,Yan Wei,Pingkai Ouyang 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.6

In this study, the production of poly(γ-glutamic acid) by Bacillus subtilis NX-2 (PGA) at different agitation speeds was investigated. Based on the analysis of specific cell growth rate (μ) and specific PGA formation rate (q_p),a two-stage strategy for agitation speed control was proposed. During the first 24 h, an agitation speed of 600rpm was used to maintain a high μ for better cell growth,which then reduced to 400 rpm after 24 h to maintain a high qp to enhance PGA production. Using this method, the maximum concentration of PGA reached 40.5 ± 0.91 g/L and the PGA productivity was 0.56 ± 0.012 g/L/h, which was 17.7 and 9.8% higher, respectively, than the best results obtained when a constant agitation speed was used. The flux distributions and the related enzymes of 2-oxoglutarate could be affected by this two-stage strategy for agitation speed. The activity of isocitrate dehydrogenase and glutamate dehydrogenase at the key node of 2-oxoglutarate increased, and more flux distribution was directed to glutamate. The flux distribution from extracellular to intracellular glutamate also increased and improved PGA production as the glutamate uptake rates increased using the agitation-shift control method.

Experimental and numerical studies on mechanical behavior of buried pipelines crossing faults

Dan F. Zhang,Xue M. Bie,Xi. Zeng,Zhen. Lei,Guo F. Du 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.1

This paper presents a study on the mechanical behavior of buried pipelines crossing faults using experimental and numerical methods. A self-made soil-box was used to simulate normal fault, strike-slip fault and oblique slip fault. The effects of some important parameters, including the displacement and type of fault, the buried depth and the diameter of pipe, on the deformation modes and axial strain distribution of the buried pipelines crossing faults was studied in the experiment. Furthermore, a finite element analysis (FEA) model of spring boundary was developed to investigate the performance of the buried pipelines crossing faults, and FEA results were compared with experimental results. It is found that the axial strain distribution of those buried pipelines crossing the normal fault and the oblique fault is asymmetrical along the fault plane and that of buried pipelines crossing the strike-slip fault is approximately symmetrical. Additionally, the axial peak strain appears near both sides of the fault and increases with increasing fault displacement. Moreover, the axial strain of the pipeline decreases with decreasing buried depth or increasing ratios of pipe diameter to pipe wall thickness. Compared with the normal fault and the strike-slip fault, the oblique fault is the most harmful to pipelines. Based on the accuracy of the model, the regression equations of the axial distance from the peak axial strain position of the pipeline to the fault under the effects of buried depth, pipe diameter, wall thickness and fault displacement were given.

Study of Oleophobic Modification of Fiber Material Surface and Its Performance

Dan Zhang,Chanjuan Huang,Wei Luo,Yuhe Wu,Zhu Long 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

In recent years, remarkable development and progresses have been made on the study of oleophobic modificationof fibers. Modified oleophobic fibers have broad application prospects not only owing to their important uses in daily life, butalso their extraordinary use in the fields of defense science and technology, and medical health care. In this study, fluorinecontainingacrylate (FP) emulsion was synthesized via emulsion polymerization method using perfluorooctyl acrylate(PFOA) as the fluorine-containing monomer, and butyl acrylate (BA) and styrene (St) as the basic monomers. In addition,SiO2 hydrosol was also prepared by water-based sol-gel reaction using tetraethyl orthosilicate (TEOS) as the precursor. Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, particle size analysis,thermogravimetric analysis and contact angle measurement were used to characterize the structural morphology and thermalstability of the FP polymer. The as-obtained FP and SiO2/FP were coated on cotton fabrics by the impregnation-curingmethod, successfully affording the cotton fabrics with oleophobic property. The application performance of the fabrics beforeand after finishing were measured and analyzed, and the effect of rubbing and soap washing on the oleophobic property of thefabrics were investigated. Then property changes, such as the anti-ultraviolet property, whiteness, breathability, and breakingstrength, of the fabrics before and after finishing were investigated. The results showed that the FP finishing agent exhibitedexcellent thermal property and satisfied the basic requirements for the fabrics finishing agents. The oleophobic property ofthe fabrics after FP emulsion finishing achieved grade 5, with no wettability to n-dodecane. The oleophobic property of theSiO2/FP treated fabrics was better than those of the FP treated fabrics, indicating that the roughen treatment of cotton fabricssurfaces using silica sol first and then coating with FP improved the oleophobic property. The combined actions of the coarsesurface structure provided by SiO2 nanoparticles and the low surface energy of the fluorine-containing polymers afforded thecotton fabric surfaces with oleophobic property. The treated fabrics retained good oleophobic performance after multipletimes of water washing and rubbings, and the physical mechanical properties of the cotton fabrics did not change muchbefore and after finishing, and thus did not affect the clothing performance of the cotton fabrics.

Research on Collaborative Filtering Algorithm based on Cloud Computing

Dan Zhang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.7

In order to solve this problem of cloud model, this paper presents another new collaborative filtering recommendation algorithm by combining the item classification and cloud model. Firstly the algorithm utilizes the item classification information and cloud model to compute items inner-similarity, and then gets the scores from neighbor items which have the highest similarity and uses their scores to forecast the unrated inner-class items. Secondly, the neighbors of user are obtained by computing the inner-class user similarities in the cloud model, providing the final forecast grade and carrying out the recommendation.

Controlled synthesis of Co₂C nanochains using cobalt laurate as precursor: Structure, growth mechanism and magnetic properties

Zhang, Yajing,Zhu, Yuan,Wang, Kangjun,Li, Da,Wang, Dongping,Ding, Fu,Meng, Dan,Wang, Xiaolei,Choi, Chuljin,Zhang, Zhidong Elsevier 2018 Journal of magnetism and magnetic materials Vol.456 No.-

<P><B>Abstract</B></P> <P>Cobalt carbides (Co<SUB>2</SUB>C and Co<SUB>3</SUB>C) nanocomposites exhibit interesting hard magnetic property, controlled synthesis of individual phase facilitates to clarify the magnetism of each, but it is difficult to obtain the single phase. We present a new approach to address this issue via a polyol refluxing process, using cobalt laurate as the precursor. The single phase Co<SUB>2</SUB>C magnetic nanochains self-assembled by nanoparticles are synthesized. The precursor is the key factor for controlling the growth kinetics of the Co<SUB>2</SUB>C nanochains. Cobalt, instead of cobalt carbides, is produced if cobalt chloride, acetate and acetylacetonate replace cobalt laurate as the precursor, respectively. The evolution of the growth process has been studied. In the formation of Co<SUB>2</SUB>C, first fcc-Co produces, then it transforms into Co<SUB>2</SUB>C by carbon diffusion process, and the produced carbon first exists in disordered state and then a small amount of them transforms into graphite. Saturation magnetization (<I>Ms</I>) of Co<SUB>2</SUB>C nanochains obtained at 300 °C for 20, 60, and 180 min are 27.1, 18.9, and 10.9 emu g<SUP>−1</SUP>, respectively. The decrease of <I>Ms</I> caused by increasing carbon content, and the carbon content are much larger than the stoichiometric ratio value of Co<SUB>2</SUB>C (9.2 wt%). The Co<SUB>2</SUB>C nanochains have mesoporous pore of 3.8 nm and the specific surface area of 48.6 m<SUP>2</SUP> g<SUP>−1</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Co<SUB>2</SUB>C magnetic nanochains are synthesized using cobalt laurate as the precursor in TEG. </LI> <LI> The precursor of cobalt laurate is the key factor for controlling the growth kinetics of Co<SUB>2</SUB>C nanochains. </LI> <LI> Ms of Co<SUB>2</SUB>C nanochains obtained at 300 °C for 20, 60, and 180 min are 27.1, 18.9, and 10.9 emu g<SUP>−1</SUP>, respectively. </LI> <LI> The decrease of Ms is caused by increasing carbon content with increasing reaction time. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We present a new approach to obtain single phase Co<SUB>2</SUB>C nanochains by using cobalt laurate as the precursor.</P> <P>[DISPLAY OMISSION]</P>

Residual detection of buparvaquone, nystatin, and etomidate in animal-derived food products in a single chromatographic run using liquid chromatography-tandem mass spectrometry

Zhang, Dan,Park, Jin-A.,Abd El-Aty, A.M.,Kim, Seong-Kwan,Cho, Sang-Hyun,Wang, Yanmei,Shim, Jae-Han,Jeong, Ji Hoon,Shin, Sung Chul,Kim, Jin-Suk,Chang, Byung-Joon,Shin, Ho-Chul Elsevier 2017 Food chemistry Vol.237 No.-

<P><B>Abstract</B></P> <P>A reliable and highly sensitive screening method based on liquid chromatography coupled withtriple-quadrupoleelectrospray tandemmass spectrometry (LC-MS/MS) analysis has been developed for the detection and quantification of three veterinary drugs, including buparvaquone, nystatin, and etomidate impurity B CRS. The tested drugs were extracted from samples of porcine muscle, pasteurized whole milk, and eggs using 10mM ammonium formate in acetonitrile followed by liquid-liquid purification with <I>n</I>-hexane. Chromatographic separation was achieved on a Phenomenex Luna C18 analytical column using 0.1% formic acid in ultrapure water (A) and acetonitrile (B) as mobile phases. All the matrix-matched calibration curves were linear (<I>R<SUP>2</SUP> </I> ≥0.9756) over the concentration levels of the drugs tested. Recovery at two spiking levels (equivalent to the limit of quantification (LOQ)=5ng/g and 2×LOQ) ranged from 72.88% to 92.59% with intra- and inter-day precisions <17%, except for porcine muscle spiked with 5ng/g nystatin (RSD=25.15%). Samples collected from markets located in Seoul, Republic of Korea, tested negative for all the drugs analyzed. In summary, this method is suitable for screening and quantifying the selected drugs in a single chromatographic run and with high selectivity in animal-derived food products meant for human consumption.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Buparvaquone, nystatin, and etomidate were analyzed in animal-derived food products using LC-MS/MS. </LI> <LI> A combination of 10mM ammonium formate in acetonitrile and <I>n</I>-hexane is sufficient to effectively extract the drugs without SPE. </LI> <LI> The performance parameters were satisfactory and acceptable. </LI> <LI> The target analytes were not detected in any of the market samples. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Perioperative Comprehensive Supportive Care Interventions for Chinese Patients with Esophageal Carcinoma: a Prospective Study

Zhang, Xiao-Dan,Zhao, Qing-Yu,Fang, Yi,Chen, Guan-Xuan,Zhang, Hui-Fang,Zhang, Wen-Xiao,Yang, Xiao-Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Objective: To assess the effects of perioperative comprehensive supportive care interventions on outcome of Chinese esophageal cancer patients in a prospective study. Methods: 60 patients with primary esophageal carcinoma were randomized into an intervention group (IG, n=31) and a control group (CG, n=29). The Chinese version of symptom checklist-90 (SCL-90) was adopted to assess their psychological status. The interventions, including health education, psychological support, stress management, coping strategies and behavior training, were carried out in 3 phases (preoperative, postoperative I and postoperative II), and psychological effects were thereafter evaluated accordingly before surgery, and 1 week, 4 weeks and 24 weeks post-surgery. Medical costs were estimated at discharge. Survival of patients was estimated each year post-surgery. General health status and satisfaction-with-hospital were surveyed by a follow-up questionnaire 4 years post-surgery. Results: All the subjects demonstrated higher scores in the preoperative phase than the normal range of Chinese population concerning 7 psychological domains including somatization, obsessive-compulsive, depression, anxiety, hostility, phobic anxiety and paranoid ideation. Although no significant difference was observed between the two groups at admission, the scores of IG, which tended to decrease at a faster rate, were generally lower than those of CG at weeks 1, 4 and 24 post-surgery. The length of hospital stay and medical costs of IG were significantly less than those of CG and satisfaction-with-hospital was better. However, there was no significant difference in 4-year survival or health status between two groups. Conclusions: Appropriate perioperative comprehensive supportive care interventions help to improve the psychological state of Chinese patients with esophageal carcinoma, to reduce health care costs and to promote satisfaction of patients and their families with hospital.