Development & research of double loop thermosyphon air-air cooler for wind power generator

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.Wind energy is well recognized as the nearest commercialized renewable energy technologies besides the water resource, it has high priority by governments, is developing rapidly worldwide. In the field of wind power, single megawatt wind power unit is becoming the mainstream of technology development and market demand [1]. On the one hand it is needed to optimize the generator structure to reduce heat generation [2], more importantly, efficient cooling system is needed to protect the generator [3]. Air-water cooled and air-air cooled are the main cooling mode for wind power generator coolers. For the air cooled type, most of the current application has simple smooth tube bundle structure, it is larger in size and heavier in weight, it has higher energy consumption and sometimes unable to meet the cooling requirements during hot summer. Lightweight design is the trends, a new type thermosyphon air cooled heat exchanger is developed, compared with the conventional one, preliminary studies indicate that it is about 29% smaller in size, 13.4% lighter in weight, 16.3% saved in energy consumption and 14.6% improved in cooling capacity.mp201

Research on management and application of tunnel engineering based on BIM technology

The emergence of BIM technology has provided powerful technical means for realizing informatization and digitization in the field of engineering construction, which remarkably promotes the transformation and advance of production and management modes in engineering construction. Presently, the application and development of BIM technology in the field of engineering construction has become increasingly mature, yet in the field of tunnel engineering, the application of BIM technology is still in its infancy. Under such a circumstance, this paper first puts forward the basic hardware and software configuration requirements for BIM technology in tunnel engineering, and elaborates the basic structure of the BIM technology implementation team from eight respects. Second, this paper elaborates the general principles and the basic process of BIM technology application in tunnel engineering. Third, the paper proposes the initial construction scheme of the tunnel engineering collaborative management platform based on BIM technology, and analyzes the feasibility of platform development deeply. Last, the BIM technology is applied to two projects including Tunnel 1 in Yinxi Railway Huanxian County and Tianjin Metro Line 6, which provides auxiliary technical means for solving practical engineering problems, and provides some reference for subsequent application researches of BIM-like technologies in tunnel engineering

Experiment study of multi-fans cooling module using different shroud structures for advanced vehicle thermal management system

As one of the most important components of the vehicle thermal management system, multi-fans cooling module can potentially be used to optimal the system performance in order to save the energy consumption and reduce the vehicle fuel consumption. In this study, a test rig has been designed, constructed and used to test the heat transfer performance of the multi-fans cooling module using four different fan shroud structures. Results indicate the separated plates, which have limited or worse effect on the performance of the system, are not recommended to be used in the multi-fans cooling module. The optimal shroud structure for multi-fans cooling module has been identified and experimentally tested. By adding shutters at the ventilation part of the fans (Shroud C) can significantly improve the overall performance of the module (Shroud A) by 13.25 % to 69.08 % under various operation conditions

Continuous low-dose cyclophosphamide plus prednisone in the treatment of relapsed and refractory multiple myeloma with severe complications

Background/objectiveWe retrospectively analyzed the effective and safety of continuous low-dose cyclophosphamide combined with prednisone (CP) in relapsed and refractory multiple myeloma (RRMM) patients with severe complications.MethodsA total of 130 RRMM patients with severe complications were enrolled in this study, among which 41 patients were further given bortezomib, lenalidomide, thalidomide or ixazomib on the basis of CP regimen (CP+X group). The response to therapy, adverse events (AEs), overall survival (OS) and progression-free survival (PFS) were recorded.ResultsAmong the 130 patients, 128 patients received therapeutic response assessment, with a complete remission rate (CRR) and objective response rate (ORR) of 4.7% and 58.6%, respectively. The median OS and PFS time were (38.0 ± 3.6) and (22.9±5.2) months, respectively. The most common AEs were hyperglycemia (7.7%), pneumonia (6.2%) and Cushing’s syndrome (5.4%). In addition, we found the pro-BNP/BNP level was obviously decreased while the LVEF (left ventricular ejection fraction) was increased in RRMM patients following CP treatment as compared with those before treatment. Furthermore, CP+X regimen further improved the CRR compared with that before receiving the CP+X regimen (24.4% vs. 2.4%, P=0.007). Also, both the OS and PFS rates were significantly elevated in patients received CP+X regimen following CP regimen as compared with the patients received CP regimen only.ConclusionThis study demonstrates the metronomic chemotherapy regimen of CP is effective to RRMM patients with severe complications

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Synthesis of Branch Fluorinated Cationic Surfactant and Surface Properties

A novel fluorinated quaternary ammonium salt cationic surfactant N,N,N-trimethyl-2-[[4-[[3,4,4,4-tetrafluoro-2-[1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl]-1,3-bis(tri-fluoromethyl)-1-buten-1-yl]oxy]-benzoyl]amino]-iodide (FQAS) was synthesized successfully, and its structure was characterized by FTIR, 1H-NMR, 19F-NMR, and MS. The surface activities of FQAS and the effect of temperature, electrolyte, and combination with hydrocarbon surfactant were investigated. The results showed that FQAS exhibited excellent surface activity and combination with hydrocarbon surfactant

Theoretical and experimental research on the influence of multiple piezoelectric effects on physical parameters of piezoelectric actuator

Compared with the traditional actuator of machinery and electricity, the piezoelectric actuator has the advantages of a compact structure, small volume, no mechanical friction, athermancy and no electromagnetic interference. Therefore, it has high application value in the fields of MEMS, bioengineering, medical science and so on. This article draws conclusions from the influence of multiple piezoelectric effects on the physical parameters (dielectric coefficient, equivalent capacity, energy conversion and piezoelectric coefficient) of piezoelectric actuators. These data from theoretical and experimental research show the following: (1) The rate between the dielectric coefficient of piezoelectric in mechanical freedom and clamping is obtained from the secondary direct piezoelectric effect, which enhances the dielectric property, increases the dielectric coefficient and decreases the coefficient of dielectric isolation; (2) Under external field, E n ( ex ) = E 1 , exterior stress T = 0, that is to say, under the boundary condition of mechanical freedom, piezoelectric can store electric energy and elasticity, which obtains power density, elastic density and an electromechanical coupling factor; (3) According to the piezoelectric strain S i ( 1 ) , piezoelectric displacement D m ( 2 ) and piezoelectric strain S i ( 3 ) of multiple piezoelectric effects, when the dielectric coefficient of the first converse piezoelectric effect ε33 is 1326 and the dielectric coefficient of the secondary direct piezoelectric effect increases to 3336, the dielectric coefficient of the ceramic chip increases. When the piezoelectric coefficient of the first converse piezoelectric effect d33 is 595 and the piezoelectric coefficient of the secondary direct piezoelectric effect decreases to 240, the piezoelectric coefficient of the ceramic chip will decrease. It is of major significance both in the applications and in basic theory to research the influence of multiple piezoelectric effects on the physical parameters of piezoelectric actuators. On the one hand, this can further increase the control precision of piezoelectric actuators. On the other hand, it can be applied to research on the physical parameters and self-sensing actuators, like piezoelectric quartz and piezoelectric ceramic self-sensing actuators, which will be of great service for MEMS

LSTM-based Flight Trajectory Prediction

Safety ranks the first in Air Traffic Management (ATM). Accurate trajectory prediction can help ATM to forecast potential dangers and effectively provide instructions for safely traveling. Most trajectory prediction algorithms work for land traffic, which rely on points of interest (POIs) and are only suitable for stationary road condition. Compared with land traffic prediction, flight trajectory prediction is very difficult because way-points are sparse and the flight envelopes are heavily affected by external factors. In this paper, we propose a flight trajectory prediction model based on a Long Short-Term Memory (LSTM) network. The four interacting layers of a repeating module in an LSTM enables it to connect the long-term dependencies to present predicting task. Applying sliding windows in LSTM maintains the continuity and avoids compromising the dynamic dependencies of adjacent states in the long-term sequences, which helps to improve accuracy of trajectory prediction. Taking time dimension into consideration, both 3-D (time stamp, latitude and longitude) and 4-D (time stamp, latitude, longitude and altitude) trajectories are predicted to prove the efficiency of our approach. The dataset we use was collected by ADS-B ground stations. We evaluate our model by widely used measurements, such as the mean absolute error (MAE), the mean relative error (MRE), the root mean square error (RMSE) and the dynamic warping time (DWT) methods. As Markov Model is the most popular in time series processing, comparisons among Markov Model (MM), weighted Markov Model (wMM) and our model are presented. Our model outperforms the existing models (MM and wMM) and provides a strong basis for abnormal detection and decision-making