scholarly journals Measuring the Reduction of the Confinement along the Evolution of a Burn Cut

2019 ◽  
Vol 9 (23) ◽  
pp. 5013
Author(s):  
Alberto Godio ◽  
Jacopo Seccatore

We provide an analysis of a tunnel opening cut in a tunnel face. In particular, we focus on the effect of a “burn cut,” which is a typical parallel hole cut. As the evolution of the opening consists of an increase in the volume of the cut prism and the consequent reduction of confinement of the holes along the initiation sequence, we analyze such an evolution using photographic documentation, as well as evaluating the reduction of confinement by measuring the energy transferred from the explosive charge to the rock mass. The energy was estimated by monitoring and analyzing the vibrations induced by the blasting at three different points. We adopted low-cost shock sensors for monitoring the effect of the detonation times at short distance from the blast (about 10 m). The results show an evident reduction of the shock transfer to the rock mass (i.e., a reduction of confinement) with the increase of the cavity opening. Nevertheless, when only the response of the piezometric sensors was considered, a disparity in behavior among the sensors was noted. On the other hand, when the sensor response was integrated over time, the behavior of all sensors normalized, showing the need to focus both on the oscillation and the duration to properly address the shock effect.

2021 ◽  
pp. 195-200
Author(s):  
Soyoung YUN-ROGER

This article will provide feedback on one of our university distance learning courses conducted during the national lockdown in 2020. The choice of the implementation modalities of this distance learning was initially guided by our decision to ensure immediate pedagogical continuity, as soon as we entered the lockdown in March, while including all the students. These principles led to a technologically 'frugal' solution, in the sense that it required low-cost computer and communication resources, as opposed to video conferencing in particular. We will see how this solution proved appropriate in terms of pedagogical continuity and inclusion, in line with the initial intention, and we will also discuss, based on student feedback, the other pedagogical benefits that it proved to have and which led us to maintain its format over time.


Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.


Author(s):  
Avi Max Spiegel

This chapter seeks to understand how Islamist movements have evolved over time, and, in the process, provide important background on the political and religious contexts of the movements in question. In particular, it shows that Islamist movements coevolve. Focusing on the histories of Morocco's two main Islamist movements—the Justice and Spirituality Organization, or Al Adl wal Ihsan (Al Adl) and the Party of Justice and Development (PJD)—it suggests that their evolutions can only be fully appreciated if they are relayed in unison. These movements mirror one another depending on the competitive context, sometimes reflecting, sometimes refracting, sometimes borrowing, sometimes adapting or even reorganizing in order to keep up with the other.


2020 ◽  
Vol 65 (4) ◽  
pp. 401-422
Author(s):  
Estelle Variot
Keyword(s):  
The One ◽  

"Etymological, Lexical and Semantic Correspondences in the Process of Feminization of Professional Names, Trades and Activities in French and Romanian Societies. The feminization of thought represented by language and of its varieties in the Roman World has allowed to highlight some convergences that come from a common linguistic heritage, often from Greek and Latin and some hesitation about adapting society to its realities. The feminization of some words which comes from an ancient process illustrates on the one hand the potential of the language and on the other hand some constraints sometimes linked to the society itself, which creates transitional periods, between matching grammatical correction and the evolution of linguistic uses over time. The possibilities of lexical enrichment (internal creation or loan) show the means available in French and Romanian and some convergences in the area of derivation, of lexical units and their etymologies. The grammatical perspective and word constructing methods make it possible to give keys for the feminization of names of trades or professions. Likewise, recording entries in the lexicon, their evolution, their assimilation or sometimes their forgetfulness, for the benefit of new constructions highlight the existence of objective and subjective criteria which teach us a lot about society as a whole. Keywords: feminization of professions, internal and external enrichment, suffixal match, use of words, grammar, lexicon, French and Romanian."


2010 ◽  
Vol 1 (1) ◽  
pp. 1-19
Author(s):  
Ahmed Akgunduz

AbstractIslamic Law is one of the broadest and most comprehensive systems of legislation in the world. It was applied, through various schools of thought, from one end of the Muslim world to the other. It also had a great impact on other nations and cultures. We will focus in this article on values and norms in Islamic law. The value system of Islam is immutable and does not tolerate change over time for the simple fact that human nature does not change. The basic values and needs (which can be called maṣlaḥa) are classified hierarchically into three levels: (1) necessities (Ḍarūriyyāt), (2) convenience (Ḥājiyyāt), and (3) refinements (Kamāliyyāt=Taḥsīniyyāt). In Islamic legal theory (Uṣūl al‐fiqh) the general aim of legislation is to realize values through protecting and guaranteeing their necessities (al-Ḍarūriyyāt) as well as stressing their importance (al‐ Ḥājiyyāt) and their refinements (taḥsīniyyāt).In the second part of this article we will draw attention to Islamic norms. Islam has paid great attention to norms that protect basic values. We cannot explain all the Islamic norms that relate to basic values, but we will classify them categorically. We will focus on four kinds of norms: 1) norms (rules) concerned with belief (I’tiqādiyyāt), 2) norms (rules) concerned with law (ʿAmaliyyāt); 3) general legal norms (Qawā‘id al‐ Kulliyya al‐Fiqhiyya); 4) norms (rules) concerned with ethics (Wijdāniyyāt = Aḵlāqiyyāt = Ādāb = social and moral norms).


Alloy Digest ◽  
1977 ◽  
Vol 26 (2) ◽  

Abstract SAF 1039 steel can be used in the hot-rolled, normalized, oil-quenched-and-tempered or water-quenched-and-tempered condition for general-purpose construction and engineering. Its manganese content is a little higher than some of the other standard carbon steels with comparable carbon levels; this gives it slightly higher hardenability and hardness. It provides medium strength and toughness at low cost. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-66. Producer or source: Carbon steel mills.


Relay Journal ◽  
2018 ◽  
pp. 360-381
Author(s):  
Gordon Myskow ◽  
Phillip A. Bennett ◽  
Hisako Yoshimura ◽  
Kyoko Gruendel ◽  
Takuto Marutani ◽  
...  

The distinction between Cooperative and Collaborative Learning approaches is not a clear one. Some use the terms interchangeably while others consider Cooperative Learning to be a type of Collaborative Learning. Still others clearly differentiate between them, characterizing Cooperative Learning as more highly structured in its procedures, involving a great deal of intervention by the teacher to plan and orchestrate group interactions. Collaborative Learning, on the other hand, presupposes some degree of learner autonomy-that groups can work effectively toward shared goals and monitor their own progress. This paper takes the view that the distinction between Cooperative and Collaborative Learning is a useful one and that both approaches can play valuable roles in fostering autonomous interaction. It argues that while Collaborative Learning formations may be the ultimate goal for teachers wishing to develop learner autonomy, Cooperative Learning is a valuable means for modeling the skills and abilities to help students get there. The discussion begins with an overview of the two approaches, focusing on their implementation in the Japanese educational context. It then presents seven highly structured Cooperative Learning activities and shows how they can be modified and extended over time to encourage more autonomous interaction.


2019 ◽  
Vol 9 (2) ◽  
pp. 157-160
Author(s):  
Ali Hasani

Background: Laser ablation method has high-yield and pure SWCNHs. On the other hand, arc discharge methods have low-cost production of SWCNHs. However, these techniques have more desirable features, they need special expertness to use high power laser or high current discharge that either of them produces very high temperature. As for the researches, the temperatures of these techniques are higher than 4727°C to vaporize the graphite. So, to become aware of the advantages of SWCNHs, it is necessary to find a new way to synthesize SWCNHs at a lower temperature. In other words, reaction field can be expandable at a moderate temperature. This paper reports a new way to synthesize SWCNHs at an extremely reduced temperature. Methods: According to this study, the role of N2 is the protection of the copper holder supporting the graphite rod by increasing heat transfer from the holder. After the current of 70 A was supplied to the system, the temperature of graphite rod was raised to 1600°C. It is obvious that this temperature is somehow higher than the melting point of palladium, 1555°C, and much lower than graphite melting point, 3497°C. Results: Based on the results, there are transitional precursors simultaneous with the SWCNHs. This composition can be created by distortion of the primary SWCNTs at the higher temperature. Subsequently, each SWCNTs have a tendency to be broken into individual horns. With increasing the concentration of the free horns, bud-like SWCNHs can be produced. Moreover, there are individual horns almost separated from the mass of single wall carbon nanohorns. This structure is not common in SWCNHs synthesized by the usual method such as arc discharge or laser ablation. Through these regular techniques, SWCNHs are synthesized as cumulative particles with diameters about 30-150 nm. Conclusion: A simple heating is needed for SWCNTs transformation to SWCNHs with the presence of palladium as catalyst. The well-thought-out mechanism for this transformation is that SWCNTs were initially changed to highly curled shape, and after that were formed into small independent horns. The other rout to synthesize SWCNHs is the pyrolysis of palm olein at 950°C with the assistance of zinc nitrate and ferrocene. Palm olein was used as a promising, bio-renewable and inexpensive carbon source for the production of carbon nanohorns.


1999 ◽  
Vol 18 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Chris E. Hogan ◽  
Debra C. Jeter

Dramatic changes in recent years in the audit market suggest the timeliness of an investigation of trends in auditor concentration and an extension of prior research (e.g., Danos and Eichenseher 1982). In recent press, large audit firms have claimed that specialization is a goal of increasing importance. Peat Marwick, for example, has restructured along industry lines, claiming to be recruiting professionals for national teams of multidisciplinary experts organized to “focus on the same industry to serve clients optimally.” On the other hand, litigation concerns might prompt auditors to diversify their risks by diversifying their clientele. In this study, we examine trends in industry specialization from 1976 to 1993 and the industry factors which may affect specialization; whether market share increases are greater for audit firms classified as specialists; and whether the nation's largest audit firms have increased their market share in the industries which they have identified as their focus industries. We find evidence that concentration levels have increased over this period, consistent with the claims of the large audit firms. We find that auditor concentration levels are higher in regulated industries, in more concentrated industries and in industries experiencing rapid growth, but lower in industries with a high risk of litigation. Levels of concentration have increased over time in nonregulated industries providing evidence that scale economies or superior efficiencies of heavy-involvement auditors are not limited to regulated industries but extend to nonregulated industries as well. We also find that for the audit firms classified as market leaders at the beginning of the year, market share has increased over time, whereas market share has declined for firms with a smaller share at the beginning of the year. This suggests that there are returns to investing in specialization.


Author(s):  
Linford D. Fisher

Although racial lines eventually hardened on both sides, in the opening decades of colonization European and native ideas about differences between themselves and the other were fluid and dynamic, changing on the ground in response to local developments and experiences. Over time, perceived differences were understood to be rooted in more than just environment and culture. In the eighteenth century, bodily differences became the basis for a wider range of deeper, more innate distinctions that, by the nineteenth century, hardened into what we might now understand to be racialized differences in the modern sense. Despite several centuries of dispossession, disease, warfare, and enslavement at the hands of Europeans, native peoples in the Americans almost universally believed the opposite to be true. The more indigenous Americans were exposed to Europeans, the more they believed in the vitality and superiority of their own cultures.


Sign in / Sign up

Export Citation Format

Share Document