• Title/Summary/Keyword: Variation of Qi

Search Result 45, Processing Time 0.023 seconds

Power Cable Ampacity and Influential Factors Analysis under Operation

  • Tong, Qiang;Qi, Jianping;Wang, Yanling;Liang, Likai;Meng, Xiangxing;Zhang, Qiang
    • Journal of Information Processing Systems
    • /
    • v.14 no.5
    • /
    • pp.1136-1149
    • /
    • 2018
  • With the increasing of urban electricity demand, making the most use of the power cable carrying capacity has become an important task in power grid system. Contrary to the rated ampacity obtained under extremely conservative conditions, this paper presents the various steady value of cable ampacity by using the changing surrounding parameters under operation, which is based on cable ampacity calculation equation under the IEC-60287 standard. To some degree, the cable ampacity analysis of actual surroundings improves the transmission capacity of cables. This paper reveals the factors that influence cable ampacity such as insulating layer thickness, allowable long-term conductor temperature, the ambient temperature, soil thermal resistance coefficient, and so on, then gives the class of the influence of these parameters on the ampacity, which plays a great role in accurately calculating the real-time ampacity and improving the utilization rate of cable in the complex external environment condition. Furthermore, the transient thermal rating of the cable is analyzed in this paper, and temperature variation of the conductor under different overload conditions is discussed, which provides effective information for the operation and control of the system.

The Effect of coenzyme QI0 Supplement On Cardiorepiratory Function and the Energy Substrates Utilization During Maximal Exercise

  • Kim, Jun-Mo
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.4
    • /
    • pp.1091-1100
    • /
    • 2008
  • The purpose of this study is to find out how energy substrate's utilizations in the maximal exercise-cardiorespiratory function and the energy metabolic variation- have the effect on before and after the supplements of coenzyme Q10(100mg per day for 8 weeks) based on the male students(CoQ10=8, placebo=8) of high school. The results of this study are as follows: Maximal oxygen uptake and maximal oxygen per weight are found to have the significant increase respectively in supplement group. Glucose is found to have the significant decrease after the supplement of CoQ10. And then FFA is found to have the significant increase. In the above results, the supplements of CoQ10 and cardiorespiratory function in the maximal exercise are found to have the improvement. CoQ10 in the anaerobic exercise spares the energy's utilization of Glucose and then is found to have the increase of the utilization of FFA. CoQ10 in the aerobic exercise is reported to have the increase of the utilization of FFA and then CoQ10 in the maximal exercise is also recognized to have the increase of the utilization of FFA, or energy substrates.

  • PDF

Study on the mechanical properties and rheological model of an anchored rock mass under creep-fatigue loading

  • Song, Yang;Li, Yong qi
    • Geomechanics and Engineering
    • /
    • v.23 no.6
    • /
    • pp.535-546
    • /
    • 2020
  • The stress environment of deep rock masses is complex. Under the action of earthquakes or blasting, the strength and stability of anchored rock masses in fracture zones or faults are affected. To explore the variation in anchored rock masses under creep-fatigue loading, shear creep comparative testing of anchored marble specimens with or without fatigue loading is performed. Considering the damage variable of rock under fatigue loading, a rheological model is established to characterize the whole shear creep process of anchored rock masses under creep-fatigue loading. The results show that (1) the overall deformation of marble under creep-fatigue loading is larger than that under only shear creep loading, and the average deformation is increased by 18.3%. (2) By comparing the creep curves with and without fatigue loading, the two curves basically coincide when the first level stress is applied, and the two curves are stable with the increase in stress level. The results show that the strain difference among the specimens increases gradually in the steady-state stage and reaches the maximum at the fourth level. (3) The shear creep is described by considering the creep mechanical properties of anchored rock masses under fatigue loading. The accuracy of this creep-fatigue model is verified by laboratory tests, and the applicability of the model is illustrated by the fitting parameter R2. The proposed model provides a theoretical basis for the study of anchored rock masses under low-frequency earthquakes or blasting and new methods for the stability and reinforcement of rock masses.

Experimental study on freezing point of saline soft clay after freeze-thaw cycling

  • Wang, Songhe;Wang, Qinze;Qi, Jilin;Liu, Fengyin
    • Geomechanics and Engineering
    • /
    • v.15 no.4
    • /
    • pp.997-1004
    • /
    • 2018
  • The brine leakage is a tough problem in artificial freezing engineering. This paper takes the common soft clay in Wujiang District as the study object, and calcium chloride solutions with six salinity levels were considered. The 'classic' cooling curve method was employed to measure the freezing point of specimens after freeze-thaw. Results indicate that four characteristic stages can be observed including supercooling, abrupt transition, equilibrium and continual freezing, strongly dependent on the variation of unfrozen water content. Two characteristic points were found from the cooling curves, i.e., freezing point and initial crystallization temperature. A critical value for the former exists at which the increment lowers. The higher the saline content approximately linearly, lower the freezing point. In the initial five cycles, the freezing point increases and then stabilizes. Besides, the degree of supercooling was calculated and its correlations with water, salt and freeze-thaw cycles were noted. Finally, an empirical equation was proposed for the relationship of freezing point and three main factors, i.e., water content, saline content and freeze-thaw cycles. Comparison of calculated and measured data proves that it is reliable and may provide guidance for the design and numerical analysis in frozen soil engineering.

Study on Male Nursing College Students' Subjectivity in Their Attitude toward Jobs (남자 간호 대학생의 직업 가치관에 대한 주관적 구조)

  • Doo, Hyun-Jung;Kim, Yoon-Sook
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.14 no.2
    • /
    • pp.167-175
    • /
    • 2008
  • Purpose: The purpose of this study was to explore the structure and characteristics of male college nursing students' personality-based career attitudes. Method: The Q-methodology was used to identify factors in male nursing students' personality-based career attitudes. A Q sample was collected from literature reviews (Kim & Kim, 2005). The subjects consisted of 30 male nursing students. Result: The results of the study show that male nursing students can be categorized into four types. The five factors extracted all had eigen values greater than 1.0 and explained approximately 50.84% of the variation in responses (32.62, 7.59, 5.70 and 4.93% respectively). The categories were labeled 'Repair intention style', 'Belief intention style', 'Stability intention style', and 'Self-regulation intention style'. Conclusion: Through a process that analyzes subjective structure, male nursing students' personality based career attitudes create occupational consciousness, professional accomplishment and professional ethics as a nursing profession. Content of curriculum and development of a reasonable and realistic course consultation program should be done.

Structural Equation Modeling of Job Engagement in Pediatric Nurses Based on the Job Crafting Model (잡 크래프팅 모델에 근거한 아동간호사의 직무열의 구조모형)

  • Kang, Jung Mi;Cho, Hun Ha
    • Child Health Nursing Research
    • /
    • v.26 no.2
    • /
    • pp.201-211
    • /
    • 2020
  • Purpose: The goal of this study was to construct a structural equation model of job engagement in pediatric nurses based on Tims and Bakker's job crafting model. Methods: In total, 203 pediatric nurses participated in this study, which was conducted to analyze the relationships among the concepts of job demands, job resources, person-job fit, job crafting and job engagement. Data were collected from July 24 to August 30, 2017, and analyzed using SPSS 20.0 and AMOS 21.0. Results: The hypothetical model appeared to fit the data. Six of the nine hypotheses selected for the hypothetical model were statistically significant. The job engagement model showed significant direct effects for job crafting, person-job fit and job resources, which collectively explained 61.5% of the variation in pediatric nurses' job engagement. Conclusion: Based on the findings of this study, a strategy will be needed to improve job resources and person-job fit in order to promote job engagement among pediatric nurses. Job crafting was affected by the factors of job resources and person-job fit, which should be addressed in job crafting promotion programs.

12-year LIDAR Observations of Tropospheric Aerosol over Hefei (31.9°N, 117.2°E), China

  • Wu, Decheng;Zhou, Jun;Liu, Dong;Wang, Zhenzhu;Zhong, Zhiqing;Xie, Chenbo;Qi, Fudi;Fan, Aiyuan;Wang, Yingjian
    • Journal of the Optical Society of Korea
    • /
    • v.15 no.1
    • /
    • pp.90-95
    • /
    • 2011
  • 12-year LIDAR observations of tropospheric aerosol vertical distribution using a Mie scattering LIDAR in Hefei ($31.9^{\circ}N$, $117.2^{\circ}E$) from 1998 to 2009 are presented and analyzed in this paper. Characters of temporal variation and vertical distribution of tropospheric aerosol over Hefei are summarized from the LIDAR measurements. The impacts of natural source and human activities on the aerosol vertical distribution over Hefei could be seen clearly. Dust particles from the north in spring could affect the aerosol distributions below about 12 km over Hefei, and aerosol scale height in April reaches $2.29{\pm}0.68\;km$. Both LIDAR measurements and surface visibility imply that aerosols in the lower troposphere have been increasing since about 2005.

Influence of a Novel Mold Inhibitor on Mechanical Properties and Water Repellency of Bamboo Fiber-based Composites

  • Qi, Yue;Huang, Yu-Xiang;Ma, Hong-Xia;Yu, Wen-Ji;Kim, Nam-Hun;Zhang, Ya-Hui
    • Journal of the Korean Wood Science and Technology
    • /
    • v.47 no.3
    • /
    • pp.336-343
    • /
    • 2019
  • Effects of a novel mold inhibitor specifically for bamboo, on the properties of composite products have been confirmed in this study. The mechanical and dimensional stability properties of bamboo fiber-based composites (BFBCs) from different bamboo species were also investigated. The results showed that Burmanica Gamble possessed the highest values of modulus of elasticity (MOE) of 33.2 GPa, modulus of rupture (MOR) of 286.9 MPa, compressive strength of 182.6 MPa and shear strength of 24.0 MPa. By contrast, Phyllostochys heterocycla among all of species showed the lowest MOE of 16.3 GPa, MOR of 170.3 MPa and compressive strength of 128.9 MPa were the lowest among all of species. Moreover, there is a remarkable variation in the swelling and water absorption between the samples with 4 h and 28 h water immersion treatment, especially Phyllostachys iridenscens. Overall, the results suggested that TCIT (Tebuconazole and 3(2H)-isothiazolone) had no significant effect on the mechanical properties compared with the control condition, and it would be utilized as an antimould of BFBCs manufacturing.

Epigenetic Regulation of Human Riboflavin Transporter 2(hRFT2) in Cervical Cancers from Uighur Women

  • Ma, Jun-Qi;Kurban, Shajidai;Zhao, Jun-Da;Li, Qiao-Zhi;Hasimu, Ayshamgul
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.6
    • /
    • pp.2485-2489
    • /
    • 2014
  • In the present study, we studied the hypermethylation of the human riboflavin transporter 2 (hRFT2) gene and regulation of protein expression in biopsies from resected tissues from Uighur cervical squamous cell carcinoma (CSCC) patients and their neighboring normal tissues. hRFT2 gene promoter region methylation sequences were mapped in cervical cancer cell line SiHa by bisulfite-sequencing PCR and quantitative detection of methylated DNA from 30 pairs of Uighur's CSCCs and adjacent normal tissues by MassARRAY (Sequenom, San Diego, CA, USA) and hRFT2 protein expression was analyzed by immunohistochemistry. In SiHa, we identified 2 CG sites methylated from all of 12CpG sites of the hRFT2 gene. Analysis of the data from quantitative analysis of single CpG site methylation by Sequenom MassARRAY platform showed that the methylation level between two CpG sites (CpG 2 and CpG 3) from CpG 1~12 showed significant differences between CSCC and neighboring normal tissues. However, the methylation level of whole target CpG fragments demonstrated no significant variation between CSCC ($0.476{\pm}0.020$) and neighboring normal tissues ($0.401{\pm}0.019$, p>0.05). There was a tendency for translocation the hRFT2 proteins from cytoplasm/membrane to nucleus in CSCC with increase in methylation of CpG 2 and CpG 3 in hRFT2gene promoter regions, which may relate to the genesis of CSCC. Our results suggested that epigenetic modifications are responsible for aberrant expression of the hRFT2 gene, and may help to understand mechanisms of cervical carcinogenesis.

Shear strength prediction of high strength steel reinforced reactive powder concrete beams

  • Qi-Zhi Jin;Da-Bo He;Xia Cao;Feng Fu;Yi-Cong Chen;Meng Zhang;Yi-Cheng Ren
    • Advances in concrete construction
    • /
    • v.17 no.2
    • /
    • pp.75-92
    • /
    • 2024
  • High Strength steel reinforced Reactive Powder Concrete (RPC) Beam is a new type of beams which has evident advantages than the conventional concrete beams. However, there is limited research on the shear bearing capacity of high-strength steel reinforced RPC structures, and there is a lack of theoretical support for structural design. In order to promote the application of high-strength steel reinforced RPC structures in engineering, it is necessary to select a shear model and derive applicable calculation methods. By considering the shear span ratio, steel fiber volume ratio, longitudinal reinforcement ratio, stirrup ratio, section shape, horizontal web reinforcement ratio, stirrup configuration angle and other variables in the shear test of 32 high-strength steel reinforced RPC beams, the applicability of three theoretical methods to the shear bearing capacity of high-strength steel reinforced RPC beams was explored. The plasticity theory adopts the RPC200 biaxial failure criterion, establishes an equilibrium equation based on the principle of virtual work, and derives the calculation formula for the shear bearing capacity of high-strength steel reinforced RPC beams; Based on the Strut and Tie Theory, considering the softening phenomenon of RPC, a failure criterion is established, and the balance equation and deformation coordination condition of the combined force are combined to derive the calculation formula for the shear bearing capacity of high-strength reinforced RPC beams; Based on the Rankine theory and Rankine failure criterion, taking into account the influence of size effects, a calculation formula for the shear bearing capacity of high-strength reinforced RPC beams is derived. Experimental data is used for verification, and the results are in good agreement with a small coefficient of variation.