• Steel and Composite Structures
• /
• v.51 no.1
• /
• pp.9-24
• /
• 2024

In order to study the shear mechanical behavior of prefabricated and assembled multi-key group stud connectors, this paper conducted push-out tests on 10 prefabricated and assembled multi-key group stud connectors, distributed in 5 groups, and detailed the failure modes of each specimen. Based on the finite element software, a total of 22 models of this type of stud connector are established, and validated the finite element models using the push-out tests. Furthermore, the effects of stud diameter, number of key groups, and spacing of key groups on the shear resistance of prefabricated and assembled multi-key group stud connectors are analyzed. Combined with the test and finite element, the force analysis is carried out for the stud and first-pouring and post-pouring concrete. The results show that the spacing and number of key groups have a significant impact on the shear capacity and shear stiffness of the specimen. For a single stud, the shear force is transferred to the surrounding concrete via the stud's root. When the stud is finally cut, the steel and the concrete plate are separated. Under vertical shear force, the top row of studs experiences the highest shear, while the middle row has the least. Based on statistical regression, a formula of assembled multi-key group stud connectors is proposed.

• Journal of the Korea Safety Management & Science
• /
• v.26 no.1
• /
• pp.15-24
• /
• 2024

The purpose of this study is to improve the stack effect of the staircase and the failure to take into account the opening of the outside door of the staircase, which are the disadvantages of the existing smoke control only vestibule. As a result of the study, the new vestibule and the staircase simultaneous smoke control are equipped with an exhaust flap damper with an effective opening area of about 0.25 m² in the upper part of the staircase, and a ventilator-type air supply fan of about 5 m³/s in the lower part, and take measures to prevent overpressure in the staircase. If you use the new simultaneous smoke control method of the vestibule and staircase, you can achieve the following effects. First, it is possible to open the external entrance door. Second, it can reduce the stack effect. Third, the staircase door closes automatically without fail. And a new method of preventing overpressure was proposed for the vestibule.

• Archives of Plastic Surgery
• /
• v.46 no.6
• /
• pp.544-549
• /
• 2019

Background As the indications for postmastectomy radiotherapy expand, innovative solutions are required to reduce operative complications and reconstructive failure after prosthetic breast reconstruction. In this study, we investigated the effectiveness of acellular dermal matrix (ADM) inlay grafts in preventing postoperative wound dehiscence of irradiated breasts in the context of prosthetic breast reconstruction. Methods A retrospective analysis was conducted of 45 patients who received two-stage prosthetic reconstruction and radiotherapy following mastectomy. An ADM graft was placed beneath the incisional site during the second-stage operation in 19 patients using marionette sutures, whereas the control group did not receive the ADM reinforcement. Patient demographics and complications such as wound dehiscence, capsular contracture, peri-prosthetic infection, cellulitis, and seroma were compared between the two groups. Results During an average follow-up period of 37.1 months, wound dehiscence occurred significantly less often in the ADM-reinforced closure group (0%) than in the non-ADM group (23.1%) (P=0.032). There was no significant difference between the two groups in relation to other complications, such as capsular contracture, postoperative infection, or seroma. Conclusions The ADM inlay graft is a simple and easily reproducible technique for preventing incisional dehiscence in the setting of radiotherapy after prosthetic breast reconstruction. The ADM graft serves as a buttress to offload tension during healing and provides a mechanical barrier against pathogens. Application of this technique may serve to reduce complications in prosthetic breast reconstruction after radiotherapy.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.222-234
• /
• 2009

How to make use of the surplus labor force is the key problem referring to success or failure of new rural building in China. The purpose of the paper is to know exactly that what the problems to the development in the rural area, especially the problem of the rural labor force. The way to solve rural labor force question is to protect the rights of peasants, eliminate the extant city and rural's partitioning pattern and give them the same treatment. Firstly, it should dominate the city and rural economic society's development; Secondly, it should dominate the markets in city and rural, and speed up the fair competition in employment; Thirdly, it should dominate the infrastructural facilities in city and rural; Fourthly, it should dominate the education and social enterprises in city and rural; Fifthly, it should dominate the social security system in city and rural. It should also enlarge the investment of funding, science technology, talented person and management. This is the only way to solve the problem of rural labor force outlet.

• Mycobiology
• /
• v.48 no.3
• /
• pp.204-209
• /
• 2020

Three hepatic failure poisoning incidents caused by Lepiota brunneoincarnata and Lepiota venenata mushrooms have been occurred in China in 2017, L. venenata has been described as a new species. However, the cyclopeptide toxins of these lethal mushrooms remain poorly understood. In this study, the composition and content of amatoxins in L. brunneoincarnata and L. venenata are analyzed and compared, the analysis of composition and content of amatoxins in L. venenata are reported for the first time. The results showed that β-amanitin (β-AMA), α-amanitin (α-AMA), amanin, and amaninamide were identified in L. brunneoincarnata, and α-AMA, amanin II (an analog of amanin), and an unknown compound were identified in L. venenata. The differences between L. brunneoincarnata and L. venenata in the identified compounds provide chemical evidence for L. venenata as a new species. Quantitative analysis shows that α-AMA concentrations in L. brunneoincarnata and L. venenata were 0.72-1.97 mg/g dry weight, β-AMA concentrations in L. brunneoincarnata were 0.57-0.94 mg/g dry weight, and β-AMA was absent in L. venenata.

• Geomechanics and Engineering
• /
• v.15 no.6
• /
• pp.1173-1182
• /
• 2018

The coal wall, gob-side backfill, and gangues in goaf, constitute the support system for Gob-side entry retaining (GER) in coal mines. Reasonably allocating and utilizing their bearing capacities are key scientific and technical issues for the safety and economic benefits of the GER technology. At first, a mechanical model of GER was established and a governing equation for coordinated bearing of the coal-backfill-gangue support system was derived to reveal the coordinated bearing mechanism. Then, considering the bearing characteristics of the coal wall, gob-side backfill and gangues in goaf, their quantitative design methods were proposed, respectively. Next, taking the No. 2201 haulage roadway serving the No. 7 coal seam in Jiangjiawan Mine, China, as an example, the design calculations showed that the strains of both the coal wall and gob-side backfill were larger than their allowable strains and the rotational angle of the lateral main roof was larger than its allowable rotational angle. Finally, flexible-rigid composite supporting technology and roof cutting technology were designed and used. In situ investigations showed that the deformation and failure of surrounding rocks were well controlled and both the coal wall and gob-side backfill remained stable. Taking the coal wall, gob-side backfill and gangues in goaf as a whole system, this research takes full consideration of their bearing properties and provides a quantitative basis for design of the support system.

• Geomechanics and Engineering
• /
• v.15 no.2
• /
• pp.721-728
• /
• 2018

The surrounding rock mass contains cracks and joints which are distributed randomly around tunnels, and in the process of tunnel blasting excavation, radial cracks could also be induced in the surrounding rock mass. In order to clearly understand the impact of radial cracks on tunnel stability, tunnel model tests and finite element numerical analysis were implemented in this paper. Two kinds of materials: cement mortar and sandstone, were used to make tunnel models, which were loaded vertically and confined horizontally. The tunnel failure pattern was simulated by using RFPA2D code, and the Tresca stresses and the stress intensity factors were calculated by using ABAQUS code, which were applied to the analysis of tunnel model test results. The numerical results generally agree with the model test results, and the mode II stress intensity factors calculated by ABAQUS code can well explain the model test results. It can be seen that for tunnels with a radial crack emanating from three points on tunnel edge, i.e., the middle point between tunnel spandrel and its top with a dip angle $45^{\circ}$, the tunnel foot with a dip angle $127^{\circ}$, and the tunnel spandrel with $135^{\circ}$ with tunnel wall, the tunnel model strength is about a half of the regular tunnel model strength, and the corresponding tunnel stability decreases largely.

• Journal of the Microelectronics and Packaging Society
• /
• v.17 no.3
• /
• pp.65-69
• /
• 2010

In this study, we investigated the effects of UBM(Under Bump Metallization) and solder composition on the drop impact reliability of wafer level packaging. Fan-in type WLP chips were prepared with different solder ball composition (Sn3.0Ag0.5Cu, and Sn1.0Ag0.5Cu) and UBM (Cu 10 ${\mu}m$, Cu 5 ${\mu}m$\Ni 3 ${\mu}m$). Drop test was performed up to 200 cycles with 1500G acceleration according to JESD22-B111. Cu\Ni UBM showed better drop performance than Cu UBM, which could be attributed to suppression of IMC formation by Ni diffusion barrier. SAC105 was slightly better than SAC305 in terms of MTTF. Drop failure occurred at board side for Cu UBM and chip side for Cu\Ni UBM, independent of solder composition. Corner and center chip position on the board were found to have the shortest drop lifetime due to stress waves generated from impact.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.5
• /
• pp.2095-2100
• /
• 2014

Objective: Most patients with advanced breast cancer experience resistance to endocrine treatment and eventual disease progression. This meta-analysis was designed to compare the efficacy and tolerability of fulvestrant 250mg with anastrozole 1mg in postmenopausal women with advanced breast cancer. Methods: Electronic literature databases (Cochrane Library, Medline, and Embase) were searched for randomized controlled trials (RCTs) published prior to August 2013. Only RCTs that compared fulvestrant 250mg to anastrozole 1mg in postmenopausal women with advanced breast cancer were selected. The main outcomes were time to treatment failure (TTF), time to progression (TTP), duration of response (DOR), clinical benefit rate, and tolerability. Results: Four RCTs covering 1,226 patients (fulvestrant, n=621; anastrozole, n=605) were included in the meta-analysis. Fulvestrant increased the DOR compared to anastrozole (HR =1.31, 95% confidence interval [CI] 1.13-1.51). There was no statistically significant difference between fulvestrant and anastrozole in terms of TTF (HR=1.02, 95%CI 0.89-1.17), complete response (RR=1.79, 95%CI, 0.93-3.43), and partial response (RR=0.91, 95%CI 0.69-1.21). As for safety, there was no statistical significance between the two groups for common adverse events. Conclusion: Fulvestrant 250mg is as effective and well-tolerated as anastrozole 1mg treatment for advanced breast cancer in postmenopausal women whose disease progressed after prior endocrine treatment. Thus, fulvestrant may serve as a reasonable alternative to anastrozole when resistance is experienced in breast cancer cases.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.2
• /
• pp.782-795
• /
• 2019

Safety is always acritical focus of exploration of ocean resources, and it is well recognized that human factor is one of the major causes of accidents and breakdowns. Our research developed a dynamic human reliability assessment approach, Predicted Mean Vote-Cognitive Reliability and Error Analysis Method (PMV-CREAM), that is applicable to monitoring the cognitive reliability of oceanauts during deep-sea missions. Taking into account the difficult and variable operating environment of manned submersibles, this paper analyzed the cognitive actions of oceanauts during the various procedures required by deep-sea missions, and calculated the PMV index using human factors and dynamic environmental data. The Cognitive Failure Probabilities (CFP) were calculated using the extended CREAM approach. Finally, the CFP were corrected using the PMV index. This PMV-CREAM hybrid model can be utilized to avoid human error in deep-sea research, thereby preventing injury and loss of life during undersea work. This paper verified the method with "Jiaolong" manned submersible 7,000 m dive test. The"Jiaolong" oceanauts CR(Corrected CFP) is dynamic from 3.0615E-3 to 4.2948E-3, the CR caused by the environment is 1.2333E-3. The result shown the PMV-CREAM method could describe the dynamic human reliability of manned submersible caused by thermal environment.