Fire Behaviors of Multilayer Latex Foam Coated by Thin Surface Fabric under Bottom Ventilation Conditions

Yiming Shen,Kai Zhang,Dongmei Huang,Chaoyi Wang,Chen Chen,De Li,Long Shi 한국고분자학회 2021 폴리머 Vol.45 No.1

The latex mattress is usually accompanied by fire risk due to its coating material and multi-layer structure. The fire behaviors of multi-layer (with a total thickness of 5 cm) latex foam coated with different fabric layer under bottom ventilation conditions were investigated experimentally. Experimental results showed that fabric coated on the surface of the multi-layer sample could significantly affect the fire behaviors. The combustion duration and peak mass loss rate of single layer sample were obtained 30% shorter and 25% larger than that of the coated samples, respectively. The effects of blending coated from the latex foam surface on the fire behaviors were found larger than those from the cotton coated sample. The total combustion duration and average fuel regression rate of cotton coated samples reduced by 34%, 43.2% when compared to those of the blending coated samples, respectively. With the increase of the number of latex foam layers, the fuel regression rate in the depth direction of the sample increases.

Nonlinear dynamic analysis of cutting head-rotor-bearing system of the roadheader

Zhilong Huang,Zhongchao Zhang,Yiming Li,Guiqiu Song,Yang He 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.3

In order to study the dynamic characteristics of cutting head and cantilever system, a nonlinear dynamic model with a 13 degrees of freedom (13-DOF) lateral torsional coupled cutting head-rotor-bearing system (CHRBS) is established. The nonlinear coupled factors of spline clearance and bearing contact force are mainly considered, the dynamic analysis of CHRBS under time-varying load is carried out. The results show that there is no positive correlation between the cutting rock thickness and the states of chaotic motion and quasiperiodic motion. The system is in the two states mentioned above when in low speed region. With the increase of rotational speed, the chaotic motion becomes periodic motion. When the hardness of rock is lower, increasing rotational speed can reduce the vibration of the system, and the cutting thickness can be increased to improve the productivity and lump rock rate. As the hardness of rocks increases, the coupled system shows complex dynamic characteristics when the rotational speed changes from low to high, and the vibration increased. When cutting hard rock, the cutting speed should be increased. However, when the speed is too high, the cutting torque of system becomes smaller. In the case of cutting hard rock, reasonable rotational speed should be chosen between improving stability and increasing cutting force. The dynamic analysis results provide strong support for the vibration reduction and dynamic design of roadheader.

Influence of Water on the Fracture Process of Marble with Acoustic Emission Monitoring

Jun Zhu,Jianhui Deng,Yiming Huang,Zhiliang He 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Water has a great influence on rock fracture process, and it is necessary to explore the activity of cracks for saturated rocks at key stress points. By uniaxial compression test and acoustic emission (AE) tests, four key points of stress-strain curve for dry and saturated marble specimens are determined. Those four key stress points include: crack closure stress (point A), crack initiation stress (point B), crack damage stress (point C) and peak stress (point D). By analyzing dominant frequencies and amplitude of AE waveforms of the whole loading process and in the vicinity of key points, the fracture process of samples was studied. The results show that there are two concentrations of dominant frequency bands in both dry and saturated marble, and the ranges of dominant frequency bands of the saturated seem wider. Due to the existence of water, the number and energy of AE waveforms decrease relatively during the whole test. This phenomenon indicates that water enhances the ductility and creep characteristics of rock. The appearance of lots of AE waveform signals with low dominant frequency is the precursor information of intense crack propagation and failure for dry rock, and the effects of water increased the number of micro-tensile failures for saturated rock in the vicinity of each key point. From point A, point B, point C to point D, the proportions of H-type bands in the vicinity of each key point for dry rock show a trend of increasing - decreasing - sharply decreasing, while those for saturated rock follow the law of increasing - decreasing - increasing.

Association analysis of polymorphisms in six keratin genes with wool traits in sheep

Sulayman, Ablat,Tursun, Mahira,Sulaiman, Yiming,Huang, Xixia,Tian, Kechuan,Tian, Yuezhen,Xu, Xinming,Fu, Xuefeng,Mamat, Amat,Tulafu, Hanikezi Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.6

Objective: The purpose of this study was to investigate the genetic effects of six keratin (KRT) genes on the wool traits of 418 Chinese Merino (Xinjiang type) (CMXT) individuals. Methods: To explore the effects and association of six KRT genes on sheep wool traits, The polymerase chain reaction-based single-strand conformation polymorphism (PCR-SSCP), DNA sequencing, and the gene pyramiding effect methods were used. Results: We report 20 mutation sites (single-nucleotide polymorphisms) within the six KRT genes, in which twelve induced silent mutations; five induced missense mutations and resulted in $Ile{\rightarrow}Thr$, $Glu{\rightarrow}Asp$, $Gly{\rightarrow}Ala$, $Ala{\rightarrow}Ser$, $Se{\rightarrow}His$; two were nonsense mutations and one was a same-sense mutation. Association analysis showed that two genotypes of the KRT31 gene were significantly associated with fiber diameter (p<0.05); three genotypes of the KRT36 gene were significantly associated with wool fineness score and fiber diameter (p<0.05), three genotypes of the KRT38 gene were significantly associated with the number of crimps (p<0.05); and three genotypes of the KRT85 gene were significantly associated with wool crimps score, body size, and fiber diameter (p<0.05). Analysis of the gene pyramiding effect between the different genotypes of the gene loci KRT36, KRT38, and KRT85, each genotype in a gene locus was combined with all the genotypes of another two gene loci and formed the different three loci combinations, indicated a total of 26 types of possible combined genotypes in the analyzed population. Compared with the other combined genotypes, the combinations CC-GG-II, CC-HH-IJ, CC-HH-JJ, DD-HH-JJ, CC-GH-IJ, and CC-GH-JJ at gene loci KRT36, KRT38, and KRT85, respectively, had a greater effect on wool traits (p<0.05). Conclusion: Our results indicate that the mutation loci of KRT31, KRT36, KRT38, and KRT85 genes, as well as the combinations at gene loci KRT36, KRT38, and KRT85 in CMXT have significant effects on wool traits, suggesting that these genes are important candidate genes for wool traits, which will contribute to sheep breeding and provide a molecular basis for improved wool quality in sheep.

An Open-switch Fault Diagnosis Method for Single-phase PWM Rectifier Based on CEEMD-DNN

Na Qin,Tianwei Wang,Deqing Huang,Yiming Zhang,Lei Ma 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.10

Based on complementary ensemble empirical mode decomposition and deep neural network (CEEMDDNN), a novel diagnosis method is proposed to discover the open-circuit faults of insulated gate bipolar transistors (IGBTs) in single-phase pulse width modulation (PWM) AC-DC rectifier, an important part of traction power supply system of high-speed railway. By virtue of the combination of signal processing and deep learning schemes, the multi-scale feature information for IGBT’s open-circuit fault diagnosis are extracted by regarding the input current of rectifier as the original signal. More clearly, CEEMD is adopted to decompose the original signal to a series of intrinsic mode function components (IMFs). Then, the correlation coefficient algorithm is used to evaluate the correlation between each of the IMFs and the original signal. Further, those IMFs that have been verified to be highly correlated with the original signal are selected as the input eigenvectors of DNN to train the IGBTs fault diagnosis network. Experimental results show that the proposed CEEMD-DNN algorithm is superior to pure DNN, empirical mode decomposition (EMD)-DNN and ensemble empirical mode decomposition (EEMD)-DNN in the sense that within the similar time-consuming situations the fault diagnosis accuracy has been improved from 73.0%, 86.0%, and 89.9% to almost 99.0%. This is mainly owing to the remarkable decomposing performance of CEEMD for complex mixed signal, and the strong feature extraction and learning abilities of DNN in pattern recognition.

Reasearch on the main factors for changes in pressure based on turbulent circulating fluidized bed coal gasification technology

Duan Feng,Jin Bao-Sheng,Huang Ya-Ji,Li Bin,Sun Yu,Wu Yiming,Zhang Ming-Yao 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

High temperature preheated air and steam as gasifying agent and coal gasification was performed in a pressurized turbulent circulating fluidized bed (CFB) gasification pilot plant to investigate the pressurized gasification process and estimate its potential. Within the scope of this paper this test facility as well as its operation behavior was described. Furthermore, the parameter pressure has been investigated regarding its influence on the syngas composition and was presented and discussed in the following. The results show that the gasification quality is improved at higher pressure because of the better fluidization in the reactor. Coal gasification at a higher pressure shows advantages in lower heat value and carbon conversion. With the gasifier pressure increased from 0.1MPa to 0.3MPa, the gas heating value is increased by 15%. Increasing the gasifier pressure would increase the carbon conversion from 57.52% to 76.76%. Also, the dry gas yield and efficiency of cold gas increase little with the increase of the gasifier pressure. The operating parameter of pressure exists at optimum operating range for this specific CFB coal gasification process.

COVID Pandemic Impact on Healthcare Provision and Patient Psychosocial Distress: A Multi-National Cross-Sectional Survey among Asia-Pacific Countries

Chung Eric,Jiann Bang-Ping,Nagao Koichi,Hakim Lukman,Huang William,Lee Joe,Lin Haocheng,Mai Dung Ba Tien,Nguyen Quang,박현준,Sato Yoshikazu,Tantiwongse Kavirach,Yuan Yiming,Park Kwangsung 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: COVID pandemic significantly affected the delivery and maintenance of healthcare system, resulting in greater utilization of digital health interventions. Materials and Methods: This multi-national cross-sectional survey was administered to clinicians working in major Asia-Pacific cities during the mandatory social lockdown period in June 2020. Clinical demographics and professional data, delivery of Andrology-related healthcare services, and patient distress based on validated questionnaires such as Depression and Anxiety Stress Scales (DASS) and Decisional Engagement Scale (DES) were collected. Results: Telehealth medicine was instituted in all the centres with the majority of centres (92.9%) reported a 50% or more reduction in out-patient related services. The numbers of phone calls, emails correspondence and educational webinars have significantly increased. Despite the provision of reasons for changes in healthcare service and delay in surgery, more than half of the patients (57.1%) rated 2 on the DASS score for the item on patients over-react to situations, while a third of the patients (35.7%) scored a 2 for DASS item on patients being more demanding or unreasonable. The DES scores were more positive with most patients reported a score above 7 out of 10 in terms of items on accepting current arrangement (85.7%), confident in clinician decision-making about treatment (92.9%) and comfortable that the decision is consistent with their preferences (71.4%). Most patients (85.7%) indicated their preferences for more detailed information on healthcare provision. Conclusions: Our study showed telehealth services were integrated early and successfully during the COVID pandemic and patients were generally receptive with minimal psychosocial distress.