20,587 research outputs found
Modelling the thermo-mechanical volume change behaviour of compacted expansive clays
Compacted expansive clays are often considered as a possible buffer material
in high-level deep radioactive waste disposals. After the installation of waste
canisters, the engineered clay barriers are subjected to
thermo-hydro-mechanical actions in the form of water infiltration from the
geological barrier, heat dissipation from the radioactive waste canisters, and
stresses generated by clay swelling under almost confined conditions. The aim
of the present work is to develop a constitutive model that is able to describe
the behaviour of compacted expansive clays under these coupled
thermo-hydro-mechanical actions. The proposed model is based on two existing
models: one for the hydro-mechanical behaviour of compacted expansive clays and
another for the thermo-mechanical behaviour of saturated clays. The elaborated
model has been validated using the thermo-hydro-mechanical test results on the
compacted MX80 bentonite. Comparison between the model prediction and the
experimental data show that this model is able to reproduce the main features
of volume changes: heating at constant suction and pressure induces either
expansion or contraction; the mean yield stress changes with variations of
suction or temperature
Linear Global Translation Estimation with Feature Tracks
This paper derives a novel linear position constraint for cameras seeing a
common scene point, which leads to a direct linear method for global camera
translation estimation. Unlike previous solutions, this method deals with
collinear camera motion and weak image association at the same time. The final
linear formulation does not involve the coordinates of scene points, which
makes it efficient even for large scale data. We solve the linear equation
based on norm, which makes our system more robust to outliers in
essential matrices and feature correspondences. We experiment this method on
both sequentially captured images and unordered Internet images. The
experiments demonstrate its strength in robustness, accuracy, and efficiency.Comment: Changes: 1. Adopt BMVC2015 style; 2. Combine sections 3 and 5; 3.
Move "Evaluation on synthetic data" out to supplementary file; 4. Divide
subsection "Evaluation on general data" to subsections "Experiment on
sequential data" and "Experiment on unordered Internet data"; 5. Change Fig.
1 and Fig.8; 6. Move Fig. 6 and Fig. 7 to supplementary file; 7 Change some
symbols; 8. Correct some typo
Nursing Care of a Case of Mediastinal Tumor Resection Combined with Postoperative Thoracic Hemorrhage after Video-assisted Thoracoscopic Surgery (VATS)
Objective: To summarize the nursing experience of a patient withpostoperative intrathoracic hemorrhage after thoracoscopic-assistedresection of the right upper mediastinal tumor through the original incision.Methods: Summarize the main points of nursing care of postoperativeintrathoracic hemorrhage after thoracoscopic mediastinal surgery, includingobservation and nursing when internal hemorrhage occurs after operation,respiratory management, activity management and pain managementmeasures. Result: After careful care, the patient recovered and dischargedsmoothly. Conclusion: It is particularly important to observe the overallobservation and take timely corresponding nursing measures for patientswith intrathoracic hemorrhage after thoracoscopic mediastinal surgery
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