Enhanced remote-sensing scale for wind damage assessment

Jianjun Luo,Daan Liang,Cagdas Kafali,Ruilong Li,Tanya M. Brown 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.3

This study has developed an Enhanced Remote-Sensing (ERS) scale to improve the accuracy and efficiency of using remote-sensing images of residential building to predict their damage conditions. The new scale, by incorporating multiple damage states observable on remote-sensing imagery, substantially reduces measurement errors and increases the amount of information retained. A ground damage survey was conducted six days after the Joplin EF 5 tornado in 2011. A total of 1,400 one- and two-family residences (FR12) were selected and their damage states were evaluated based on Degree of Damage (DOD) in the Enhanced Fujita (EF) scale. A subsequent remote-sensing survey was performed to rate damages with the ERS scale using high-resolution aerial imagery. Results from Ordinary Least Square regression indicate that ERS-derived damage states could reliably predict the ground level damage with 94% of variance in DOD explained by ERS. The superior performance is mainly because ERS extracts more information. The regression model developed can be used for future rapid assessment of tornado damages. In addition, this study provides strong empirical evidence for the effectiveness of the ERS scale and remote-sensing technology for assessment of damages from tornadoes and other wind events.

Reconstruction of a near-surface tornado wind field from observed building damage

Luo, Jianjun,Liang, Daan,Weiss, Christopher Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.3

In this study, residential building damage states observed from a post-tornado damage survey in Joplin after a 2011 EF 5 tornado were used to reconstruct the near-surface wind field. It was based on well-studied relationships between Degrees of Damage (DOD) of building and wind speeds in the Enhanced Fujita (EF) scale. A total of 4,166 one- or two-family residences (FR12) located in the study area were selected and their DODs were recorded. Then, the wind speeds were estimated with the EF scale. The peak wind speed profile estimated from damage of buildings was used to fit a translating analytical vortex model. Agreement between simulated peak wind speeds and observed damages confirms the feasibility of using post-tornado damage surveys for reconstructing the near-surface wind field. In addition to peak wind speeds, the model can create the time history of wind speed and direction at any given point, offering opportunity to better understand tornado parameters and wind field structures. Future work could extend the method to tornadoes of different characteristics and therefore improve model's generalizability.

Reconstruction of a near-surface tornado wind field from observed building damage

Jianjun Luo,Daan Liang,Christopher Weiss 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.3

In this study, residential building damage states observed from a post-tornado damage survey inJoplin after a 2011 EF 5 tornado were used to reconstruct the near-surface wind field. It was based onwell-studied relationships between Degrees of Damage (DOD) of building and wind speeds in the EnhancedFujita (EF) scale. A total of 4,166 one- or two-family residences (FR12) located in the study area wereselected and their DODs were recorded. Then, the wind speeds were estimated with the EF scale. The peakwind speed profile estimated from damage of buildings was used to fit a translating analytical vortex model. Agreement between simulated peak wind speeds and observed damages confirms the feasibility of usingpost-tornado damage surveys for reconstructing the near-surface wind field. In addition to peak wind speeds,the model can create the time history of wind speed and direction at any given point, offering opportunity tobetter understand tornado parameters and wind field structures. Future work could extend the method totornadoes of different characteristics and therefore improve model‟s generalizability.

Enhanced remote-sensing scale for wind damage assessment

Luo, Jianjun,Liang, Daan,Kafali, Cagdas,Li, Ruilong,Brown, Tanya M. Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.19 No.3

This study has developed an Enhanced Remote-Sensing (ERS) scale to improve the accuracy and efficiency of using remote-sensing images of residential building to predict their damage conditions. The new scale, by incorporating multiple damage states observable on remote-sensing imagery, substantially reduces measurement errors and increases the amount of information retained. A ground damage survey was conducted six days after the Joplin EF 5 tornado in 2011. A total of 1,400 one- and two-family residences (FR12) were selected and their damage states were evaluated based on Degree of Damage (DOD) in the Enhanced Fujita (EF) scale. A subsequent remote-sensing survey was performed to rate damages with the ERS scale using high-resolution aerial imagery. Results from Ordinary Least Square regression indicate that ERS-derived damage states could reliably predict the ground level damage with 94% of variance in DOD explained by ERS. The superior performance is mainly because ERS extracts more information. The regression model developed can be used for future rapid assessment of tornado damages. In addition, this study provides strong empirical evidence for the effectiveness of the ERS scale and remote-sensing technology for assessment of damages from tornadoes and other wind events.

Evaluation of the efficacy of unipolar and bipolar spinal dorsal root ganglion radiofrequency thermocoagulation in the treatment of postherpetic neuralgia

Jianjun Zhu,Ge Luo,Qiuli He,Ming Yao 대한통증학회 2022 The Korean Journal of Pain Vol.35 No.1

Background: Different views have been proposed on the radiofrequency treatment modes and parameters of radiofrequency thermocoagulation of the spinal dorsal root ganglion for the treatment of postherpetic neuralgia (PHN). It is urgent to identify a more effective therapy for patients with PHN. Methods: Patients who underwent radiofrequency thermocoagulation therapy for PHN were retrospectively reviewed and were divided into a radiofrequency thermocoagulation (CRF) and double neddles radiofrequency thermocoagulation (DCRF). The pain scores (numerical rating scale, NRS) were evaluated at the following time points: before the operation, 1 day, 3 months, 6 months, 1 year, and 2 years after operation. The incidence of complications and the degree of pain relief were evaluated. The in vitro ovalbumin experiment was used to indicate the effects of radiofrequency thermocoagulation. Results: Compared with the preoperative NRS scores, the postoperative NRS scores decreased significantly; the NRS scores of the DCRF group was lower than that of the CRF group at all time points from 6 months to 2 years following the operation. The total effective rate of the DCRF group was significantly higher than that of the CRF group at 2 years following the operation. The incidence of numbness in the DCRF group was higher than that noted in the CRF group. The ovalbumin experiments in vitro indicated that the effects of radiofrequency thermocoagulation were optimal when the distance between the two needles was 5 mm. Conclusions: DCRF with a 5 mm spacing exhibits a longer duration and higher effective rate in the treatment of PHN and is worth promoting.

Research on Operation Performance of Women Oriented Cross-country Teaching in College: an Empirical Analysis Based on Multimedia Computer

Luo Hong,Long Xiaodong,Tao Ganchen,Long Jianjun,Wan Shaoyong,Chen Yuanping 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.9

With the development of computer multimedia technology, the new educational model, which is represented by the educational technology, has emerged in the field of education in our country. Sports’ teaching is a participatory teaching and learning activities, also, the current network resources is relatively abundant, so that design and development of a multimedia network teaching platform is very necessary. In this paper, we test the performance evaluation of directional cross-country teaching by using multimedia. Result shows that college students will have significant advantage after using teaching media, both in weight, vital capacity, sit ups, and 800 meters. After the experiment, experimental classes get higher score than comparative classes in 100 meters directional cross country ability test. The application of computer multimedia is helpful in physical education; it can improve students' learning enthusiasm and the effect is remarkable.

Influence of tip clearance on pressure fluctuations in an axial flow pump

Jianjun Feng,Xingqi Luo,Pengcheng Guo,Guangkuan Wu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Rotor-stator interaction in axial pumps can produce pressure fluctuations and further vibrations even damage to the pump system in some extreme case. In this paper, the influence of tip clearance on pressure fluctuations in an axial flow water pump has been investigated by numerical method. Three-dimensional unsteady flow in the axial flow water pump has been simulated with different tip clearances between the impeller blade tip and the casing wall. In addition to monitoring pressure fluctuations at some typical points, a new method based on pressure statistics was proposed to determine pressure fluctuations at all grid nodes inside the whole pump. The comparison shows that the existence of impeller tip clearance magnifies the pressure fluctuations in the impeller region, from the hub to shroud. However, the effect on pressure fluctuation in the diffuser region is not evident. Furthermore, the tip clearance vortex has also been examined under different tip clearances.

Trichloroethylene injures rat liver and elevates the level of peroxisomal bifunctional enzyme (Ehhadh)

Nuanyuan Luo,Qunqun Chang,Xiaohu Ren,Peiwu Huang,Wei Liu,Li Zhou,Yungang Liu,Jianjun Liu 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.3

Background Trichloroethylene (TCE) is a common industrial solvent and an occupational toxicant. TCE exposure can cause severe hepatotoxicity, but its mode of action is poorly understood. Many studies have shown TCE-induced liver damage in mice, while few have examined the effects of TCE in rats. Objective To explore the effects of TCE in Sprague–Dawley (SD) rats and the potential mechanisms in TCE-induced hepatocytotoxicity. Results The liver index and activities of liver damage marker enzymes (ALT, AST and ALP) in rat serum were elevated along with the increase in TCE dose, while the levels of total proteins and albumin in serum were reduced. The results suggest that TCE is hepatotoxic in rats. 2D-DIGE electrophoresis showed that the levels of 66 liver proteins in TCE-treated rats were abnormally altered (39 up-regulated and 27 down-regulated). In these proteins, six enzymes were related to liver damage and carcinogenesis as indicated by bioinformatics analysis, and Western blot analysis confirmed the alterations of three of them, i.e., aldehyde dehydrogenase 2 (Aldh2), glutathione S-transferase Mu 1 (Gstm1) and peroxisomal bifunctional enzyme (PBE, also named as Ehhadh). PBE was the only protein elevated in a dose dependent manner. Whether PBE can be a biomarker of TCE hepatotoxicity needs to be further studied. Conclusion These findings indicate that TCE induces liver injury in rats.

Ozone infusiblization and curing mechanism of polysilazane ceramic precursor fibers

Li Xiaohong,Luo Xiaoyu,Li Jing,Li Jinxia,Yang Jiahao,Ahmad Zahoor,Bao Zhihao,Zhang Xiao,Chen Jianjun 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.5

An appropriate infusible method plays a vital role as one of the key processes of the fabrication of polymer-derived ceramic fibers. In this work, ozone curing, a novel room temperature controllable curing strategy was used to prepare SiCN ceramic fibers. Some circular pores were observed on the surface of the obtained SiCN ceramic fibers. The tensile strength of the fibers was also investigated. To reveal the ozone-curing mechanisms of the PSZ fibers and the formation process of the circular pores, the FT-IR, SEM, OM, XRD and TG were characterized. The results showed that the Si–H bonds and Si-CH3 groups in the PSZ molecule were oxidized gradually to form oxygen-containing groups such as Si–OH, Si–O-Si and C = O in the ozone curing process, which contributed to the curing and weight gain of the PSZ fibers. Moreover, a hydrolysis reaction between Si-NH-Si and H2O might further accelerate the curing of the PSZ fibers. An unexpected result of the hydrolysis reaction is the formation of some circular pores on the surface layer of the PSZ fibers. This strategy provides a method to design, adjust and control the microstructure and composition of silicon-based ceramic fibers, and the obtained SiCN fibers may be used as catalyst support, bacterial culture and other fields.

Numerical investigation of supercavity geometry and gas leakage behavior for the ventilated supercavities with the twin-vortex and the re-entrant jet modes

Xu Haiyu,Luo Kai,Dang Jianjun,Li Daijin,Huang Chuang 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1

To investigate the supercavity geometry and gas flow structure for the supercavities with two closure types under the different flow conditions, an inhomogeneous multiphase model with the SST turbulence model was established, and validated by experimental results. The results show that two distinct regions exist inside the supercavity, which include the downstream flow region along the gas-water interface and the reverse flow region. For the twin-vortex supercavity, the internal gas leaks from the supercavity boundary by two paths: the supercavity surface and the two-vortex tubes. Increasing Froude number leads to more internal gas stripped from the supercavity surface. Two types of gas loss exist for the reentrant jet supercavity with high Froude number, one type is the steady process of gas loss, and the major gas-leaking path is the supercavity surface rather than supercavity closure region. The other type is the unsteady periodic ejection, and the gas cluster of periodic ejection is merely a small part of the gas stored inside the supercavity.