103 research outputs found

    Effect of the changed electrolytic cell on the current efficiency in FFC Cambridge process

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    Low current efficiency of the FFC Cambridge process made it no obvious advantages in cost compared with the traditional process to produce metals. Effect of the changed electrolysis cell on the current efficiency has been studied. Put the cathode into an alumina tube with a hole can efficiently avoid short circuit and the cathode contaminated by carbon produced from graphite anode. The results show that the current efficiency can be improved greatly by reducing the electric field intensity in the electrolysis cell. The high background current is mainly caused by the electronic conductivity in the electrolysis cell. Otherwise, pollution of the cathode is avoided, the depletion of the anode sharply decreases and the deoxidation of the samples greatly improve when using the improvement electrolysis cell

    Study on performance degradation and damage modes of thin-film photovoltaic cell subjected to particle impact

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    It has been a key issue for photovoltaic (PV) cells to survive under mechanical impacts by tiny dust. In this paper, the performance degradation and the damage behavior of PV cells subjected to massive dust impact are investigated using laser-shock driven particle impact experiments and mechanical modeling. The results show that the light-electricity conversion efficiency of the PV cells decreases with increasing the impact velocity and the particles’ number density. It drops from 26.7 to 3.9% with increasing the impact velocity from 40 to 185 m/s and the particles’ number densities from 35 to 150/mm², showing a reduction up to 85.7% when being compared with the intact ones with the light-electricity conversion efficiency of 27.2%. A damage-induced conversion efficiency degradation (DCED) model is developed and validated by experiments, providing an effective method in predicting the performance degradation of PV cells under various dust impact conditions. Moreover, three damage modes, including damaged conducting grid lines, fractured PV cell surfaces, and the bending effects after impact are observed, and the corresponding strength of each mode is quantified by different mechanical theories

    Optical Flow Sensor/INS/Magnetometer Integrated Navigation System for MAV in GPS-Denied Environment

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    The drift of inertial navigation system (INS) will lead to large navigation error when a low-cost INS is used in microaerial vehicles (MAV). To overcome the above problem, an INS/optical flow/magnetometer integrated navigation scheme is proposed for GPS-denied environment in this paper. The scheme, which is based on extended Kalman filter, combines INS and optical flow information to estimate the velocity and position of MAV. The gyro, accelerator, and magnetometer information are fused together to estimate the MAV attitude when the MAV is at static state or uniformly moving state; and the gyro only is used to estimate the MAV attitude when the MAV is accelerating or decelerating. The MAV flight data is used to verify the proposed integrated navigation scheme, and the verification results show that the proposed scheme can effectively reduce the errors of navigation parameters and improve navigation precision

    catena-Poly[cobalt(II)-bis­(μ-3,7-dichloro­quinoline-8-carboxyl­ato-κ3 N,O:O′)]

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    In the crystal structure of the title compound, [Co(C10H4Cl2NO2)2]n, the CoII cation lies on a twofold rotation axis. Each cation is N,O-chelated by the carboxyl­ate anions of two 3,7-dichloro­quinoline-8-carboxyl­ate ligands. The second carboxyl­ate O atom of each ligand coordinates to the CoII cation of an adjacent mol­ecule, linking the cations into a linear chain. Strong inter­chain π–π stacking inter­actions are observed in the crystal structure (perpendicular distance 3.42 Å, centroid-to-centroid distance 3.874 Å

    Measurement of distal intramural spread and the optimal distal resection by naked eyes after neoadjuvant radiation for rectal cancers

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    BACKGROUND: The safe distance between the intraoperative resection line and the visible margin of the distal rectal tumor after preoperative radiotherapy is unclear. We aimed to investigate the furthest tumor intramural spread distance in fresh tissue to determine a safe distal intraoperative resection margin length. METHODS: Twenty rectal cancer specimens were collected after preoperative radiotherapy. Tumor intramural spread distances were defined as the distance between the tumor’s visible and microscopic margins. Visible tumor margins in fresh specimens were identified during the operation and were labeled with 5 - 0 sutures under the naked eye at the distal 5, 6, and 7 o’clock directions of visible margins immediately after removal of the tumor. After fixation with formalin, the sutures were injected with nanocarbon particles. Longitudinal tissues were collected along three labels and stained with hematoxylin and eosin. The spread distance after formalin fixation was measured between the furthest intramural spread of tumor cells and the nanocarbon under a microscope. A positive intramural spread distance indicated that the furthest tumor cell was distal to the nanocarbon, and a negative value indicated that the tumor cell was proximal to the nanocarbon. The tumor intramural spread distance in fresh tissue during the operation was 1.75 times the tumor intramural spread distance after formalin fixation according to the literature. RESULTS: At the distal 5, 6, and 7 o’clock direction, seven (35%), five (25%), and six (30%) patients, respectively, had distal tumor cell intramural spread distance > 0 mm. The mean and 95% confidence interval of tumor cell intramural spread distance in fresh tissue during operation was − 0.3 (95%CI − 4.0 ~ 3.4) mm, − 0.9 (95%CI − 3.4 ~ 1.7) mm, and − 0.4 (95%CI − 3.5 ~ 2.8) mm, respectively. The maximal intraoperative intramural spread distances in fresh tissue were 8.8, 7, and 7 mm, respectively. CONCLUSIONS: The intraoperative distance between the distal resection line and the visible margin of the rectal tumor after radiotherapy should not be less than 1 cm to ensure oncological safety

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

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    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

    Removal of Impurity Elements from the Molten Aluminum: Modeling and Validation

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    In order to remove impurity elements like H, Na, Ca, Li from the molten aluminium, many processes, such as injecting inert or reactive gases, reactive or unreactive powders, and slag refining, have been used in last several decades. In the current paper, mathematical models for the removal of impurity elements from molten aluminium in the batch and continuous reactor were developed and validated with industrial measurements
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