scholarly journals The inextensible string

1943 ◽  
Vol 33 ◽  
pp. 13-17
Author(s):  
A. G. Walker

An object to which we were all introduced at an early stage in mechanics is the inextensible string. This appears frequently without causing much trouble, but there is one type of problem which, in my opinion, stands apart from the rest, and which certainly caused me a lot of trouble. Such a problem is when impulses are given to a system which includes an inextensible string, as, for example, a system consisting of two rigid parts joined by a string. If an impulse is applied to one of these parts, an impulsive tension (T) may be set up in the string, which, in turn, gives an impulse to the other part. One new quantity, T, has appeared, and one equation in addition to the ordinary dynamical equations is thus required before the problem of finding the change in motion of the system can be solved. It is at this stage that opinions can differ, for this extra equation depends essentially upon what concept of an inextensible string is being adopted, and there is more than one. The usual procedure is to employ a “geometrical equation” based upon the argument that the two ends must have equal component velocities in the line of the string as long as the string is taut. This seems almost obvious when described in such general terms, and is followed by such eminent writers as Routh and Loney, amongst others. I suggest, however, that this method implies a concept which leads to results contrary to common-sense and to everyday experience. This is best illustrated by a simple example.

Author(s):  
Carmen García-Alba

This study is part of a larger research study (doctoral dissertation), in which a comparative study with adolescent samples is done: 50 anorexic restricting patients (ANP), 50 patients diagnosed with depression (DP) and 50 non patients (NP). The proposed objective is two-fold: 1) To try to clarify the existing relationship between Anorexia (AN) and Depression (D), investigated from diverse disciplines but without conclusive results. 2) To detect in the ANP personality different traits from those of other groups, which should, if possible, allow to detect them at an early stage for an adequate prognosis. The current article presents the Rorschach findings in relation to the cognitive functioning of the ANP. In them, the following has been detected: (1) An information processing similar to that of the other groups, even with a more complete (L ≤ .99), more complex (DQ+↑) and better discriminated (Zd↑) grasp of the stimulus; (2) Mediating processes very similar to those of the other groups, sharing with them the perceptive maladjustments (X–%↑) and an excessive individualism (Xu%↑); (3) A clearly differentiating ideation disorder. Definitely, the ANP use predominantly ideation (M↑), but their thought, usually well-adjusted (MQo↑), presents eventual operations of delusional type (MQnone↑). Above that, their thinking is marked by a great passivity (Mp↑), which makes them more vulnerable to accept ideas without criticizing them and it results in a very inefficient thinking, which spins around these concepts without finding solutions, entering into a sort of ruminating which is completely unproductive. The differences toward the obsessive pathology are established. The discriminant analysis conducted with all the Rorschach variables that resulted as significant throughout the research, provides quite a consistent function which discriminates the ANP: MQnone↑, Mp↑, FD↓, Ma↑, MQo↑, AdjD↑, Sum H↑, (H)↑. Based on this we can understand that these adolescents, being in a developmental period of big changes and disorientations in relation with their own image, confronted with life events, and possibly starting off with some biologic vulnerability: (1) Due to the alterations of their ideation, accept without criticism (Mp) irrational ideas dominating in our culture, in which slimness appears as the only model, synthesis of intelligence, beauty and success; remaining captured in this type of mental activity (MQnone), which they cannot escape nor criticize (Mp), despite they reason adequately on other topics (MQo); (2) Their alterations of self-perception [(H)] make them hide themselves in a fantasized image, which is the axis of their interests and the only thing that really matters to them; (3) The resources they have to decide on behaviors and to finish these deliberately (AdjD), and their scarce tendency to the introspection (FD) lead to their decision of not eating, based on distorted and passively accepted thinking, which has great power and thus, so difficult to modify. Finally, based on the Rorschach data obtained, the hypothesis of a personality disorder as underlying pathology is pointed out.


Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.


2006 ◽  
Vol 4 (2) ◽  
pp. 125-137 ◽  
Author(s):  
Erik Lundestad

Even though the philosophy of common sense is not justifi able as such, the assump- tion upon which it rests, namely that there are things which we are not in position to doubt is correct. The reason why Thomas Reid was unable to bring this assumption out in a justifi able manner is that his views, both on knowledge and nature, are to be considered dogmatic. American pragmatists such as Charles Sanders Peirce and John Dewey on the other hand, may be seen as offering us a ‘critical’ and post-Darwinian philosophy of common sense.


2015 ◽  
Vol 6 (2) ◽  
pp. 253-274
Author(s):  
Vered Noam

The rabbinic halakhic system, with its many facets and the literary works that comprise it, reflects a new Jewish culture, almost completely distinct in its halakhic content and scope from the biblical and postbiblical culture that preceded it. By examining Jewish legislation in the area of corpse impurity as a test case, the article studies the implications of Qumranic halakhah, as a way-station between the Bible and the Mishnah, for understanding how Tannaitic halakhah developed. The impression obtained from the material reviewed in the article is that the direction of the “Tannaitic revolution” was charted, its methods set up, and its principles established, at a surprisingly early stage, before the destruction of the Second Temple, and thus at the same time that the Qumran literature was created.


Author(s):  
Rachana Kamtekar

Chapter 1 lays out the methodological approach employed throughout the book, which is to pay attention to the dialectical dependence of what the main speaker in the dialogue says on the intellectual problem(s) set up in the dialogue both by himself and the other speakers. To illustrate, Chapter 1 describes Socrates’ use of the method of hypotheses from the Meno and Phaedo to answer questions that go beyond his claims to knowledge in the Republic.


Author(s):  
David M. Wittman

Galilean relativity is a useful description of nature at low speed. Galileo found that the vertical component of a projectile’s velocity evolves independently of its horizontal component. In a frame that moves horizontally along with the projectile, for example, the projectile appears to go straight up and down exactly as if it had been launched vertically. The laws of motion in one dimension are independent of any motion in the other dimensions. This leads to the idea that the laws of motion (and all other laws of physics) are equally valid in any inertial frame: the principle of relativity. This principle implies that no inertial frame can be considered “really stationary” or “really moving.” There is no absolute standard of velocity (contrast this with acceleration where Newton’s first law provides an absolute standard). We discuss some apparent counterexamples in everyday experience, and show how everyday experience can be misleading.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Elodie Di-Falco ◽  
Johan Bourbon ◽  
Isalyne Sbaffe ◽  
Jean-Daniel Kaiser

AbstractAlsace, in particular Haut-Rhin, is one of the main clusters of COVID-19 in France. There has been a shortage of essential supplies in the area, especially alcohol-based hand sanitizer. In this context, and in accordance with the decree dated March 6, 2020, our hospital management team asked us to start local production of alcohol-based handrub. This was a real challenge: In one week, we had to implement the production of handrub to meet the needs of a 1,400-bed hospital. The production had to comply with the French preparation guidelines and take place on specific premises, with qualified and calibrated equipment, by qualified staff, under the supervision of a pharmacist. The other big challenge we faced was the supply of pharmaceutical raw and packaging materials. During this particular critical period, all suppliers were out of stock. Here, we describe the organizational set-up and the decisions made, e. g., to use technical-grade ethanol before the publication of the decrees dated March 13 and March 23, 2020.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 752
Author(s):  
Chung-Guei Huang ◽  
Avijit Dutta ◽  
Ching-Tai Huang ◽  
Pi-Yueh Chang ◽  
Mei-Jen Hsiao ◽  
...  

A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.


2004 ◽  
Vol 5 (1) ◽  
pp. 43-58
Author(s):  
Jeffrey S. Galko ◽  

The ontological question of what there is, from the perspective of common sense, is intricately bound to what can be perceived. The above observation, when combined with the fact that nouns within language can be divided between nouns that admit counting, such as ‘pen’ or ‘human’, and those that do not, such as ‘water’ or ‘gold’, provides the starting point for the following investigation into the foundations of our linguistic and conceptual phenomena. The purpose of this paper is to claim that such phenomena are facilitated by, on the one hand, an intricate cognitive capacity, and on the other by the complex environment within which we live. We are, in a sense, cognitively equipped to perceive discrete instances of matter such as bodies of water. This equipment is related to, but also differs from, that devoted to the perception of objects such as this computer. Behind this difference in cognitive equipment underlies a rich ontology, the beginnings of which lies in the distinction between matter and objects. The following paper is an attempt to make explicit the relationship between matter and objects and also provide a window to our cognition of such entities.


1998 ◽  
Vol 162 ◽  
pp. 211-213
Author(s):  
S. Isobe

Astronomy is an important science in understanding a human environment. However, it is thought by most politicians, economists, and members of the public that astronomy is a pure science having no contribution to daily human activities except a few matters relating to time. The Japanese government is studying a reorganisation of our school system to have 5 school days per week, instead of 6 days per week, and this July its committee made a recommendation to reduce school hours for science and set up new courses for practical computers and environmental science. I currently made a proposal. It is very difficult for most of the school pupils, who will have non-scientific jobs, to understand science courses currently taught in school, because each science is taught independently from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not greatly help their understanding of global environmental problems.


Sign in / Sign up

Export Citation Format

Share Document