Development and Performance Study of an Apparatus for Imparting Lateral Cyclic Load on Model Pile Foundation

2006 ◽  
Author(s):  
Sudip Basak

The environment prevalent in ocean necessitates the pile foundations supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system introducing progressive reduction in the bearing capacity as well as settlement of the pile foundation. To understand the effect of lateral cyclic load on pile group, a new apparatus, consisting of mechanically and electrically controlled components, has been designed and fabricated. Each of the components of this apparatus is calibrated and a series of trial tests are performed for its performance study. This paper presents detailed description of the apparatus, calibration and operating principle of each of its components, the observations made from trial experiments and the relevant conclusions drawn therefrom.

2014 ◽  
Vol 891-892 ◽  
pp. 24-29 ◽  
Author(s):  
Sudip Basack ◽  
Abhik Kumar Banerjee

The pile foundations supporting offshore structures are required to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition produces progressive degradation in the pile-soil interactive performance which is likely to introduce significant reduction in bearing capacity with increased settlement and displacements. This paper is based on a numerical model developed by the Authors to study the response of pile foundation under lateral cyclic load in layered soil. The model is validated with a field test data and thereafter, parametric studies have been carried out. A brief description of the works conducted and the major conclusions drawn are highlighted in this paper.


2020 ◽  
Vol 10 (2) ◽  
pp. 103-111
Author(s):  
Andrey K. Babin ◽  
Andrew R. Dattel ◽  
Margaret F. Klemm

Abstract. Twin-engine propeller aircraft accidents occur due to mechanical reasons as well as human error, such as misidentifying a failed engine. This paper proposes a visual indicator as an alternative method to the dead leg–dead engine procedure to identify a failed engine. In total, 50 pilots without a multi-engine rating were randomly assigned to a traditional (dead leg–dead engine) or an alternative (visual indicator) group. Participants performed three takeoffs in a flight simulator with a simulated engine failure after rotation. Participants in the alternative group identified the failed engine faster than the traditional group. A visual indicator may improve pilot accuracy and performance during engine-out emergencies and is recommended as a possible alternative for twin-engine propeller aircraft.


2014 ◽  
Vol 45 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Robert J. Calin-Jageman ◽  
Tracy L. Caldwell

A recent series of experiments suggests that fostering superstitions can substantially improve performance on a variety of motor and cognitive tasks ( Damisch, Stoberock, & Mussweiler, 2010 ). We conducted two high-powered and precise replications of one of these experiments, examining if telling participants they had a lucky golf ball could improve their performance on a 10-shot golf task relative to controls. We found that the effect of superstition on performance is elusive: Participants told they had a lucky ball performed almost identically to controls. Our failure to replicate the target study was not due to lack of impact, lack of statistical power, differences in task difficulty, nor differences in participant belief in luck. A meta-analysis indicates significant heterogeneity in the effect of superstition on performance. This could be due to an unknown moderator, but no effect was observed among the studies with the strongest research designs (e.g., high power, a priori sampling plan).


Author(s):  
Jyoti Baijal

Examination stress is a ubiquitous phenomenon that has, in the present times, adversely affected the learning outcomes and performance of the students at all levels- primary, secondary or higher education. It’s increasing intensity specifically among students appearing for high stakes board examination evokes a response from the teaching fraternity at the earliest. The reason being that a prolonged experience of stress with respect to evaluative situations is bound to prove detrimental to the mental, physical and emotional well-being of the students. For the nation to develop and progress towards a knowledge society, it is imperative that the students are taught to cope with stressful stimuli and improve performance. Study-Skills Training is an intervention intended to improve their study and test- taking habits and skills. It is based on a cognitive-deficit model which is directed towards improving a variety of cognitive activities that affect the organization, processing and retrieval of information and thereby help in reducing the experience of examination stress. Systematic desensitization as a process can be used to unlearn anxiety reactions by replacing the anxiety response with a calm, relaxed state. Thus, a combination of study-skills training and systematic desensitization has been shown to be effective and superior in alleviating test anxiety


2020 ◽  
Vol 15 ◽  
pp. 155892502097575
Author(s):  
Huiling Wang ◽  
Bin Zhou

Facial masks are beauty products which composed of a facial mask paper and beauty solution. Silk contains the amino acid structure closest to the human skin, and has the skin-friendly, cosmetic and antibacterial functions, but the common method for making nonwoven facial mask paper is not suitable for silk. In this paper, the silkworm’s spinning path is intervened manually to obtain a smart silk facial mask paper (SMC) of controllable thickness, so that the sericin on the silk fiber is well preserved. In the experiment where the SMC is compared with the nonwoven 384-cuprammonium rayon facial mask paper (CRMC) which is the most widely used in the market, it is found that the ways of forming the two facial mask paper are completely different, and therefore the morphologies under SEM are obviously different. The thickness of the SMC is 0.183 mm and the areal weight of it is 38.0 g/m2. It is very close to the CRMC (0.187 mm, 38.4 g/m2). The porosity of the SMC is 84.0%, which is slightly lower than that of the CRMC (86.3%), but its pores are well distributed. Compared with the CRMC, the smart SMC has higher dry and wet strength, lower elongation, slightly lower air permeability and liquid entrainment rate, and better antibacterial performance.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 415
Author(s):  
Dayong Ning ◽  
Zihao Li ◽  
Gangda Liang ◽  
Qibo Wang ◽  
Weifeng Zou ◽  
...  

Considering the further exploration of the ocean, the requirements for deep-sea operation equipment have increased. Many problems existing in the widely used deep-sea hydraulic system have become increasingly prominent. Compared with the traditional deep-sea hydraulic system, actuators using a paraffin phase change material (PCM) have incomparable advantages, including lightweight structure, low energy consumption, high adaptability to the deep sea, and good biocompatibility. Thus, a deep-sea drive microunit (DDM) based on paraffin PCM is proposed in this paper. The device adopts a flexible shell, adapting to the high-pressure environment of the deep-sea based on the principle of pressure compensation. The device realizes the output of displacement and force through the electrothermal drive, which can be used as actuator or power source of other underwater operation equipment. The microunit successfully completes the functional verification experiments in air, shallow water, and hydrostatic pressure of 110 MPa. In accordance with experimental results, a reasonable control curve is fitted, highlighting its potential application in deep-sea micro electro mechanical systems, especially in underwater soft robot.


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