An Experimental Investigation of the Feasibility of “Self-Sensing” Shape Memory Alloy Based Actuators

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
K. Malukhin ◽  
K. F. Ehmann
Keyword(s):  
Shape Memory ◽  
Working Conditions ◽  
Voltage Drop ◽  
The Self ◽  
Order System ◽  
System Response ◽  
Crystallographic Structure ◽  
The Relationship ◽  
Insulation Condition

Shape memory alloys (SMAs) change their crystallographic structure and shape during heating/cooling and, as a consequence, their electrical resistance also changes. This allows the determination of the location of a SMA-based structure in space without separate sensors by suitably measuring this change. In this paper, this “self-sensing” concept is explored in SMA wire-type actuators. Step responses, expressed in terms of resistance (voltage drop) across the wire, and the corresponding displacement changes during heating/cooling, were measured. It was shown that the relationship between the displacement and the voltage drop can be approximated by a linear regression with a correlation coefficient close to 1. System identification has shown that SMA wire actuator performance can be best approximated by first or by second order system response depending on the thermal insulation condition of the actuator. The resolution and the sensitivity of the self-sensing method were evaluated based on experimental data and it was shown that their minimal values were less than 1.7μm and 0.7μm, respectively, thus supporting the feasibility of the “self-sensing concept.” Both values exponentially increase with the increase in the range of the measured displacements whose magnitudes vary under different working conditions.

scholarly journals Evaluation of diagnostic thresholds dependability for tribologic signals received in the environment disturbed by vibroacoustic and functional signals

2015 ◽  
Vol 36 (1) ◽  
pp. 17-32
Author(s):  
Paweł Lindstedt ◽  
Marek Zboiński ◽  
Maciej Deliś ◽  
Jerzy Manerowski
Keyword(s):  
Working Conditions ◽  
Operation Time ◽  
Working Environment ◽  
Cauchy Product ◽  
Diagnostic Thresholds ◽  
Diagnostic Threshold ◽  
Complete Set ◽  
The Relationship ◽  
Insufficient Number

Abstract Determination of dependable diagnostic thresholds for tribologic signals received e.g. from antifriction bearings (in particular for insufficient number of measurements, only 4÷5) is a really difficult task due to complexity of working environment where such bearings are operated. Typical working environment for such objects must take account for operation time under various working conditions and accompanying (and disturbing) signals, e.g. vibroacoustic ones. The sought assessment of the relationship between diagnostic signals and environmental noise can be determined from convolution of both diagnostic and environments signals that make up the complete set of received information. The convolution of these two series of signals can be obtained from an algorithm based on the Cauchy product. Then one has to find the coherence factor and the square of amplitude gain for the set of diagnostic signals with reference to various sets of signals received from environment, which makes it possible to evaluate cohesion of the investigated series of signals, thus their suitability to determine diagnostic threshold for tribologic signals intended for the analysis.

scholarly journals GENERAL ANALYSIS OF STRESS AND DEFORMATION OF PARTS MOVING WITH HIGH VELOCITY IN A LIQUID OR GAS (REVIEW ARTICLE)

2021 ◽  
pp. 71-76
Author(s):  
Mykola Prokopenko
Keyword(s):  
Working Conditions ◽  
Thermal Fatigue ◽  
Uniaxial Stress ◽  
Material Strength ◽  
High Speeds ◽  
Analytical Review ◽  
Stress And Deformation ◽  
The Relationship

The article provides an analytical review and analysis of stresses and deformations of parts moving at high speeds in a liquid or gas. The working conditions of materials and parts of turbines (blades, rotor and casing) operating at high temperatures and loads are analyzed. The main ways of solving the problem of ensuring the strength of such parts are presented. The main ways to solve the problem of reliability of parts or the product as a whole are given: mathematical modeling (calculated determination of strength, durability and reliability); physical modeling (model testing); testing of full-scale products in reproducible real or operational conditions.It is impossible to speak about the strength of a part only from the calculation of deformations and stresses, even taking into account their change over time, so it is necessary to have strength criteria that establish the relationship between the strength parameters. It is emphasized that in the general case, the criterion of strength should answer the question: will the part collapse or not with the known laws of change in time of stresses, strains and temperatures It is shown that the considered standard characteristics of creep and long-term strength can be directly used in calculations only for those parts in which the uniaxial stress state at constant stresses and temperature is realized, when the working conditions of the material fully meet the test conditions of materials.An analytical view of deformation diagrams is considered as the main means of carrying out practical calculations of material strength. It is shown that in order to determine the stresses and strains in parts that move at high speeds in a liquid or gas, it is necessary to take into account the model of parts exploitation, the processes of creep and thermal fatigue of the material, and the unsteadiness of load processes. Keywords: stresses and deformations of turbine parts; deformation diagram; operating model of turbine parts; creep and thermal fatigue; nonstationarity of loading processes  

Personality‐descriptive verbs

1988 ◽  
Vol 2 (2) ◽  
pp. 81-96 ◽  
Author(s):  
Boele De Raad ◽  
Erik Mulder ◽  
Klaas Kloosterman ◽  
Willem K. B. Hofstee
Keyword(s):  
Factor Analysis ◽  
Internal Structure ◽  
The Self ◽  
Factor Analyses ◽  
Effective Instrument ◽  
The Relationship

This article describes the derivation of a taxonomy of personality‐descriptive verbs. In the introduction the verb domain is delineated relative to other domains of the language of personality. It is argued that verbs are theoretically useful in bridging the gap between trait language and act language. The aim is to provide a representative and effective instrument for registering judgements on personality. In a first study the steps are described that were followed to arrive at a list of personality‐descriptive verbs. Both the present authors and layjudges (n=22) took part in this. Five hundred and forty‐three verbs resulted from this study. Study 2 (n=200) describes the determination of the internal structure of the domain of verbs through factor analysis of both self‐ and partner‐ratings. By applying a method of rotation to perfectly congruent weights the verb‐structure turned out to be invariant under the self‐ and partner‐conditions. The last part of the study investigates the relationship between personality‐descriptive verbs and adjectives. Regressions of verb‐ratings on the adjective‐ratings and of adjective‐ratings on the verb‐ratings were calculated and factor analyses were performed on the residual matrices. The results show the existence of additional verb‐dimensions above those already established in the adjective domain.

scholarly journals Hubungan Self Efficacy Terhadap Motivasi Belajar Biologi Siswa Kelas XI Pada Pembelajaran Daring

2021 ◽  
Vol 9 (3) ◽  
pp. 234-241
Author(s):  
Sindia Dwi Yolandita ◽  
◽  
Nurul Fauziah
Keyword(s):  
Self Efficacy ◽  
Sampling Technique ◽  
The Self ◽  
Learning Motivation ◽  
Coefficient Of Determination ◽  
Positive Contribution ◽  
Motivation To Learn ◽  
The Relationship ◽  
Academic Year

This research is correlation research. This study aims to determine the relationship between self-efficacy and motivation to learn biology in class XI SMA Negeri 14 Pekanbaru in the 2020/2021 academic year. The instruments used in data collection are observation, interviews, questionnaires, and documentation. This research was conducted on April 26 to June 3, 2021. The sampling technique in this study used a saturated sampling technique. The number of samples in this study was 180 students. The questionnaire distributed consisted of 30 statements. The results of data analysis correlation coefficient (rcount) of 0,22 with a significant level of 5% has a correlation in the low category. From hypothesis testing, it was obtained tcount (3,0) > ttable (1,66). This means that Ho is rejected, and Ha is accepted. Then from the results of the analysis of the coefficient of determination of the self-efficacy variable (X) it gave a positive contribution to learning motivation (Y) which was obtained by 5% while 95% was determined by other variables or factors that influenced student learning motivation which were not discussed in this study.

scholarly journals Impact of selected parameters on the loading process with cutting screw heads

2019 ◽  
Vol 2 (1) ◽  
pp. 249-256
Author(s):  
Tomasz Wydro
Keyword(s):  
Working Conditions ◽  
Cutting Process ◽  
Kinematic Parameters ◽  
Loading Process ◽  
Cutting Machine ◽  
Auxiliary Process ◽  
The Relationship

Abstract The article presents the influence of selected constructional and kinematic parameters of cutting screw heads on the loading process. The loading process is often referred to as an auxiliary process, because in the entire operation of the head the cutting process is considered dominant. Proper determination of the relationship between the cutting process and the loading process allows to understand how individual constructional and kinematic parameters of cutting heads and the cutting machine on which they are installed have an impact on each other. This knowledge gives potential users an opportunity to determine a reason for the lack of effective loading in the working conditions of a given wall. Besides construction and kinematic parameters, shielded loaders also have an impact on the loading process. The use of a shielded loader allows for improving the efficiency of the loading process, i.e. increasing the percentage of output loaded in the whole of the output transferred by the head.

Zwischen Erinnern und Vergessen

2011 ◽  
Vol 2011 (1) ◽  
pp. 155-174 ◽  
Author(s):  
Michela Summa
Keyword(s):  
Present Article ◽  
Sense Of Self ◽  
Phenomenological Analysis ◽  
The Self ◽  
Narrative Self ◽  
Minimal Self ◽  
Dementia Patients ◽  
Spatio Temporal ◽  
The Relationship

The present article explores some currently disputed issues regarding the relationship between temporality, memory, and the self. To exemplify and to concretely examine the problems under consideration, a phenomenological analysis of dementia illnesses is proposed. The first objective of this article is to develop an appropriate concept of the self, apt to describe the experience of dementia patients. To this aim, the different positions in the debate regarding the preservation of the self in dementia patients are first critically assessed. Subsequently, it is shown how the phenomenological distinction between the basic sense of self, often indicated as the minimal self, and the higher forms of narrative self-consciousness and identity can fruitfully contribute in this debate. The second objective of the article is a more concrete qualification of the minimal self. Particularly, the determination of the minimal self as un-extended in time is challenged. On the basis of the phenomenology of time and implicit bodymemory, and still exemplarily referring to the analysis of dementia illnesses, it will be argued that a concrete description of basic self-experience necessarily needs to take its spatio-temporal unfolding into account.

Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern?

1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston
Keyword(s):  
Patient Management ◽  
External Quality Assessment ◽  
Oral Anticoagulant Therapy ◽  
Warfarin Dosage ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
International Normalised Ratio ◽  
The Uk ◽  
The Relationship

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.

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