base displacement
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2021 ◽  
Author(s):  
Hassiba Beghzim ◽  
Toufik Karech ◽  
Tayeb Bouzid

Abstract The analysis of the failure due to the effect of the propagation of normal and reversed faults with different angles of inclination and by sliding through the Ourkiss dam isstudied numerically. Mainly at the end of construction and at the highest water level, for this purpose the non-linear finite difference method is used considering four fault angles of inclination, activated at the center of the base of the embankment.The results of the study show that the shear stress values increase with the increase of the vertical base displacement imposed in both conditions of the dam state, and this for both normal and overturned faults.


2021 ◽  
pp. 107754632110359
Author(s):  
César A Morales

A novel design procedure for tuned mass dampers in isolated structures is presented. The proposed optimization method is specifically developed to control base displacements or to solve the large isolator displacement problem in this type of structures under earthquakes. Therefore, it is based on a displacement transmissibility function, T, a particular case of the general transmissibility concept, which comes from Vibration Isolation. Three contributions are application of new seismic displacement narrowbandness, simpler relative transmissibility function, and compound design of isolation plus tuned mass damper. A standard isolated model is used to show that the base displacement can be controlled at levels in the proximity of the ground motion ( T ≈ 1), which results in a positive comparison with previous isolation and tuned mass damper solutions; this is one of the main conclusions and it is based on novelty three above; in fact, other solutions in the literature compare their attained displacements with respect to the structure without tuned mass damper. Comparison with isolated results is not, therefore, possible herein, but it is not desirable either; actually, what is possible is a positive and more demanding comparison, which is with respect to the very seismic ground displacement itself. The large isolator displacement problem can be solved or attenuated by properly designing a tuned mass damper subsystem jointly with the isolation one.


2021 ◽  
Vol 5 (2) ◽  
pp. 18-24
Author(s):  
Renas Rajab Asaad

In this article, we'll learn about the concepts of instruction organized in computer organization. On the premise of accessibility of ALU operands sorts of CPU organization is moreover endorsed in this article. When the constructing agent forms an Instruction it changes over the instruction from its memory helpers shape to standard machine language format called the "Instruction organize". Within the preparation of change, the constructing agent must decide the sort of instruction, change over typical names and express documentation to a base/displacement organize, decide the lengths of certain operands, and parse any strict and constants. An instruction arrangement characterizes the format of bits of instruction, in terms of its constituent parts. An instruction arrangement must incorporate an opcode and verifiably or unequivocally, zero or more operands. Each unequivocal operand is referenced utilizing one of tending to modes. Arrange must, certainly or unequivocally, show tending to the mode for each operand. For most instruction sets, more than on instruction used.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mayumi Ikeda ◽  
Akiko Mori

Abstract Background Pelvic floor muscles support the pelvic organs and control voiding. The first choice in the repair of pelvic floor function that is damaged during pregnancy and delivery is pelvic floor muscle training, which involves repeated muscle relaxation and contraction. However, as muscle contractions cannot be visualised, it is difficult to assess whether patients understand how to contract them. Therefore, we assessed patients’ comprehension of pelvic floor muscle contraction by comparing two teaching methods, vaginal palpation and transabdominal ultrasound, following vaginal delivery. We hypothesised that vaginal palpation is better than transabdominal ultrasound in this regard. Methods This randomised controlled trial conducted in facilities in Tokyo, Japan between July 2018 and January 2019 included women aged ≥ 20 years at 4–6 weeks after vaginal delivery. The randomisation involved website-based centralised allocation. The primary outcome was a change in bladder base displacement during pelvic floor muscle contraction before and after training, which was measured using transabdominal ultrasound. Participants performed three contractions for 3 s, and the mean value was used for statistical analysis. The secondary outcome was a change in understanding the contraction before and after training, which was measured using a five-point Likert scale questionnaire. Outcomes were analysed using Welch’s t-test. Results Sixty-five participants were randomly allocated to the vaginal palpation group (n = 32) and transabdominal ultrasound group (n = 33). Baseline characteristics were similar between the groups. Changes in bladder base displacement were not significantly different between the groups (p = 0.181). Within-group analyses showed that bladder base displacement was large in both groups after the respective intervention. There were no significant differences in any of the outcomes between the two groups before and after the intervention. Conclusions Vaginal palpation and transabdominal ultrasound might be useful for comprehending pelvic floor muscle contraction after vaginal delivery. Trial registration: UMIN 000032304. Registered 18 April 2018, https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000036820.


2019 ◽  
Vol 57 (2) ◽  
pp. 245-248
Author(s):  
Aaron M. Foglio ◽  
Jonathan Y. Lee ◽  
Sanjay Naran ◽  
Lindsay A. Schuster ◽  
Alexander Davit ◽  
...  

Patients presenting with a unique unilateral cleft phenotype may be at risk of nasal airway obstruction which can be exacerbated by presurgical infant orthopedic (PSIO) appliance therapy and lip taping. Four patients presented to the UPMC Children’s Hospital of Pittsburgh Cleft-Craniofacial Center with a cleft phenotype characterized by: An anteriorly projected greater alveolar segment and medial collapse of the lesser segment posteriorly, leading to cleft alar base displacement posteromedial to the anteriorly projected greater segment. Resultant bilateral nasal airway obstruction: cleft ala drape over the leading edge of the greater segment’s alveolus (cleft side obstruction) and caudal septum displacement secondary to attachments to the orbicularis oris from the noncleft side (noncleft side obstruction). The patient described presented at 3 months old from an outside institution, where PSIO therapy was undertaken. A second opinion was sought due to concern of significant difficulty in breathing and feeding with the PSIO oral plate. Lip-nose adhesion (LNA) was elected and airway obstruction was immediately relieved after this intervention. Lip-nose adhesion releases the tethered cleft side alar base from the pyriform rim of the posteromedially collapsed lesser segment and unites the superior lip and nostril sill—relieving the cleft side nostril obstruction. During the LNA, the caudal septum is surgically released from the anterior nasal spine and is uprighted, relieving the obstructed noncleft nostril. In this cleft anatomy, the treatment alternatives of modification to the PSIO appliance or LNA should be carefully considered in consultation with the surgeon, PSIO provider, and the infant’s caretakers.


2019 ◽  
Vol 11 (1) ◽  
pp. 278
Author(s):  
Quanwu Zhang ◽  
Zhiguo Shi ◽  
Jiazeng Shan ◽  
Weixing Shi

Near-fault pulse motions will cause excessive and much larger base displacement in traditional isolated structures than common earthquake motions. The new isolation system inspired by the “sacrificial bonds and hidden length” biomechanics of an abalone shell can control the base displacement efficiently and reach almost the same vibration isolation efficiency as a semi-active control system. The current research is confined to the lumped mass model and cannot uncover the exact performance of isolators and structures in practical applications. A user subroutine is developed based on the interface of UEL in Abaqus. Subsequent verification has been done in both the lumped mass model and 3D complex model with Abaqus, Matlab/Simulink, and SAP2000. It can be revealed from the comparative results that the calculation accuracy of the secondary developed user subroutine can meet the demand of design and research.


2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Jonathan Salvi ◽  
Egidio Rizzi ◽  
Emiliano Rustighi ◽  
Neil S. Ferguson

Tuned mass dampers (TMDs) are typically introduced and calibrated as natural passive control devices for the vibration mitigation of the steady-state response of primary structures subjected to persistent excitations. Otherwise, this work investigates the optimum tuning of TMDs toward minimizing the transient structural response. Specifically, a single-degree-of-freedom (SDOF) system is considered as a primary structure, with added TMD, subjected to pulse-like excitations. First, the system is analytically analyzed, within the time domain, for unit impulse base displacement, through Laplace transform. Then, the tuning process is numerically explored by an optimization procedure focused on an average response index, to extract the optimum condition toward best TMD calibration. The efficiency of the proposed control device is then assessed and demonstrated through further post-tuning numerical tests, by considering as dynamic loadings: first, a time unit impulse base displacement, coherent with the source description above; second, different pulse-like excitations, to detect the effectiveness of the so-conceived TMD for generic ideal shock actions; third, a set of nonstationary earthquake excitations, to enquire the achievable level of seismic isolation. It is shown that this leads to a consistent passive TMD in such a transient excitation context, apt to mitigate the average response. Additionally, the present tuning forms a necessary optimum background for a possible upgrade to a hybrid TMD, with the potential addition of an active controller to the so-optimized TMD, to achieve even further control performance, once turned on, specifically for abating the peak response, too.


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