scholarly journals Simulation of the Vibrations Produced to the Human Body During Operation of the Bucket Wheel Excavators. A Case Study of ERc 1400-30/7 Type Excavator

Mining Revue ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 33-49
Author(s):  
Ildiko Brînaş
Keyword(s):  
Dynamic Response ◽  
Human Body ◽  
Rotation Speed ◽  
Homogeneous Material ◽  
Hard Material ◽  
Virtual Model ◽  
Virtual Sensor ◽  
Sudden Appearance ◽  
Over Time

Abstract The paper deals with the analysis of the dynamic response over time of the excavator boom during operation. For a start, we determined the variation in time of the forces acting on the rotor shaft, due to the excavation. These forces have high values and a slow variation over time, which depends on the rotation speed of the bucket wheel and the number of buckets installed on it. A virtual model of the BWE boom was proposed, for which the dynamic response in time due to the excavation forces was determined, for a point in the main cabin of the BWE. A virtual sensor has been attached to this point corresponding to seat of the operator. The simulation of the dynamic response over time was performed taking into account a global damping of 2% of the critical damping. The simulation was performed both for the excavation of a homogeneous material and for the case of a shock (a sudden appearance of an inclusion of hard material during the cutting of the homogeneous material).

When Culturally Significant Songs are Decontextualised: The Initiation Song Somagwaza, A Case Study

2018 ◽  
Vol 28 (2) ◽  
Author(s):  
T Dowling ◽  
Somikazi Deyi ◽  
Anele Gobodwana
Keyword(s):  
Qualitative Research ◽  
Comparative Method ◽  
Popular Song ◽  
Focus Group Discussions ◽  
Group Discussions ◽  
Ritual Music ◽  
Constant Comparative Method ◽  
Small Focus ◽  
Over Time

While there have been a number of studies on the decontextualisation and secularisation of traditional ritual music in America, Taiwan and other parts of the globe, very little has been written on the processes and transformations that South Africa’s indigenous ceremonial songs go through over time. This study was prompted by the authors’ interest in, and engagement with the Xhosa initiation song Somagwaza, which has been re-imagined as a popular song, but has also purportedly found its way into other religious spaces. In this article, we attempted to investigate the extent to which the song Somagwaza is still associated with the Xhosa initiation ritual and to analyse evidence of it being decontextualised and secularised in contemporary South Africa. Our methodology included an examination of the various academic treatments of the song, an analysis of the lyrics of a popular song, bearing the same name, holding small focus group discussions, and distributing questionnaires to speakers of isiXhosa on the topic of the song. The data gathered were analysed using the constant comparative method of analysing qualitative research.

Thinning in mature eastern white pine: 43-year case study

2002 ◽  
Vol 78 (4) ◽  
pp. 539-549 ◽  
Author(s):  
Paul D Anderson ◽  
John C Zasada ◽  
Glen W Erickson ◽  
Zigmond A Zasada
Keyword(s):  
Genetic Diversity ◽  
Dna Analysis ◽  
Large Diameter ◽  
White Pine ◽  
Thinning Intensity ◽  
Pine Regeneration ◽  
Volume Production ◽  
Pine Stands ◽  
Over Time

A white pine (Pinus strobus L.) stand at the western margin of the species range, approximately 125 years of age at present, was thinned in 1953 from 33.5 m2 ha-1 to target residual basal areas of 18.4, 23.0, 27.5, and 32.1 m2 ha-1 . Repeated measurement over the following 43-years indicated that the greatest total volume production and the greatest number of large diameter trees occurred in the unit of highest residual density. Over time, the distribution of stems was predominantly random although mortality between 1979 and 1996 resulted in a tendency for clumping in the 23.0 and 27.5 m2 ha-1 treatments. DNA analysis indicated that thinning intensity had little effect on the genetic diversity of residual white pine. This study suggests that mature white pine stands in northern Minnesota may be managed at relatively high densities without loss of productivity. However, regardless of overstory density, there was little or no white pine regeneration occurring in this stand. Key words: thinning, growth, genetic diversity, molecular markers, spatial pattern, regeneration

scholarly journals Can politically oriented interventions in built heritage contribute to its authenticity? Erbil Citadel’s Babylonian Gate as a case study

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed Awadh Jasim ◽  
Laura Hanks ◽  
Katharina Borsi
Keyword(s):  
Cultural Value ◽  
Cultural Issues ◽  
Built Heritage ◽  
Projection Screen ◽  
Conflicting Demands ◽  
Existential Issue ◽  
Over Time

AbstractToday, the concept of built heritage authenticity is a projection screen for conflicting demands and thus a ‘contested field’. Short-sighted readings started to drag the concept behind different ill-considered treatises, in which some heritage aspects loosely outweighed other aspects. Archaeological perspectives that tend to freeze heritage structures in time, such as those that are privileged upon other contemporary socio-cultural issues, while political takes also overshadowed other epistemological prospects, and vice versa. Repercussions have made inclusion of what is regarded as ‘inevitable changes’ within the built context problematic as to the re-interpretation and thus assessment of its authenticity. Despite their possible momentary threat to the latter, these changes may add to the cultural value of the context over time, granting new potential that may instead boost its authenticity. This paper investigates the potential continuity of Erbil Citadel’s Babylonian Gate as an inevitable change within the site’s built context by studying the Gate’s controversial political impacts on the context’s authenticity. This study affirms that authenticity is a transcendental value of an open-ended progressive nature, which cannot be reduced to a specific period or properties within the historical chronology of built heritage. Hence, authenticity should be approached as a meaningful existential issue, while revelation of its essence and thus its dimension entails precise scrutiny of both the tangibles and intangibles of the context. However, to be part of its authenticity, any change in the context should be adaptable and possibly incorporated as a new value within its cultural strata, thus enabling progressive support for site authenticity.

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Populism and Religion in Brazil: The View from Education Policy

2021 ◽  
pp. 1-15
Author(s):  
Catarina Ianni Segatto ◽  
Mário Aquino Alves ◽  
Andrea Pineda
Keyword(s):  
Education Policy ◽  
Historical Analysis ◽  
Secondary Data ◽  
Right Wing ◽  
Religious Groups ◽  
Welfare Services ◽  
National Congress ◽  
Over Time

This article is a case study of Brazil, a country where Catholic-based organizations have historically played a key role in providing education and welfare services. Since the 1980s, these organizations have supported progressive changes at both the national and subnational levels. Nevertheless, the influence of religion on education policy has shifted in the last few decades. Pentecostal and Neopentecostal groups have gained prominence through representatives in the National Congress, and, in 2018, formed a coalition enabling the election of a right-wing populist President. We analyse the trajectory of religious groups’ influence on Brazil’s education policy over time (colonization to the 1980s, the 1980s to the beginning of the 2000s, and the 2000s until now) through a qualitative-historical analysis of primary and secondary data. This article argues that both Catholic and Protestant groups have influenced progressive changes in Brazil’s education policy, but they also share conservative ideas impeding further advances.

scholarly journals The multiplicity of halal standards: a case study of application to slaughterhouses

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ali Abdallah ◽  
Mohammed Abdel Rahem ◽  
Antonella Pasqualone
Keyword(s):  
Food Products ◽  
Regulatory Framework ◽  
Close Collaboration ◽  
Western Countries ◽  
Production Processes ◽  
Islamic Countries ◽  
Certification And Accreditation ◽  
Over Time

AbstractFood products suitable for Muslim consumers should be halal certified, particularly when their origins or production processes are doubtful. However, there is a multiplicity of halal standards. This situation may generate confusion, particularly for producers in Western countries who would like to certify their products in order to export them to Islamic countries. This study analyzed the reasons underlying the multiplicity of standards and reviewed the attempts of harmonization over time. Then, the case study of application to slaughterhouses was considered, by comparing four different halal standards (namely GSO 993:2015, OIC/SMIIC 1:2019, HAS 23103:2012, and MS 1500:2019) representative of different geographic areas. Animal stunning was critically examined, comparing tradition with modernity. The study evidenced that the basic requirements related to slaughtering are common to all the halal standards considered, but several differences occur in more specific details. Only a close collaboration between the authorities of all the countries involved in issuing halal certifications will lead to a homogeneous regulatory framework with unified certification and accreditation procedures, increasingly required in a globalized market.

scholarly journals Signal Classification Algorithms over Time Selective Channels

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1714
Author(s):  
Mohamed Marey ◽  
Hala Mostafa
Keyword(s):  
Block Code ◽  
Classification Problem ◽  
Classification Performance ◽  
Signal Classification ◽  
Final Decision ◽  
Time Block ◽  
Channel Response ◽  
Over Time ◽  
Parallel Fashion

In this work, we propose a general framework to design a signal classification algorithm over time selective channels for wireless communications applications. We derive an upper bound on the maximum number of observation samples over which the channel response is an essential invariant. The proposed framework relies on dividing the received signal into blocks, and each of them has a length less than the mentioned bound. Then, these blocks are fed into a number of classifiers in a parallel fashion. A final decision is made through a well-designed combiner and detector. As a case study, we employ the proposed framework on a space-time block-code classification problem by developing two combiners and detectors. Monte Carlo simulations show that the proposed framework is capable of achieving excellent classification performance over time selective channels compared to the conventional algorithms.

scholarly journals Influence of Hydrogeochemistry on Tunnel Drainage in Evaporitic Formations: El Regajal Tunnel Case Study (Aranjuez, Spain)

2021 ◽  
Vol 13 (3) ◽  
pp. 1505
Author(s):  
Ignacio Menéndez Pidal ◽  
Jose Antonio Mancebo Piqueras ◽  
Eugenio Sanz Pérez ◽  
Clemente Sáenz Sanz
Keyword(s):  
High Speed ◽  
Civil Engineering ◽  
Saturation Index ◽  
The Subject ◽  
Under Construction ◽  
Underground Flow ◽  
Very High ◽  
Over Time

Many of the large number of underground works constructed or under construction in recent years are in unfavorable terrains facing unusual situations and construction conditions. This is the case of the subject under study in this paper: a tunnel excavated in evaporitic rocks that experienced significant karstification problems very quickly over time. As a result of this situation, the causes that may underlie this rapid karstification are investigated and a novel methodology is presented in civil engineering where the use of saturation indices for the different mineral specimens present has been crucial. The drainage of the rock massif of El Regajal (Madrid-Toledo, Spain, in the Madrid-Valencia high-speed train line) was studied and permitted the in-situ study of the hydrogeochemical evolution of water flow in the Miocene evaporitic materials of the Tajo Basin as a full-scale testing laboratory, that are conforms as a whole, a single aquifer. The work provides a novel methodology based on the calculation of activities through the hydrogeochemical study of water samples in different piezometers, estimating the saturation index of different saline materials and the dissolution capacity of the brine, which is surprisingly very high despite the high electrical conductivity. The circulating brine appears unsaturated with respect to thenardite, mirabilite, epsomite, glauberite, and halite. The alteration of the underground flow and the consequent renewal of the water of the aquifer by the infiltration water of rain and irrigation is the cause of the hydrogeochemical imbalance and the modification of the characteristics of the massif. These modifications include very important loss of material by dissolution, altering the resistance of the terrain and the increase of the porosity. Simultaneously, different expansive and recrystallization processes that decrease the porosity of the massif were identified in the present work. The hydrogeochemical study allows the evolution of these phenomena to be followed over time, and this, in turn, may facilitate the implementation of preventive works in civil engineering.

Queering the New Woman: Ideals of Modern Femininity in The Ladies’ Journal, 1915–1931

NAN Nü ◽  
2014 ◽  
Vol 16 (2) ◽  
pp. 341-362
Author(s):  
Joshua A. Hubbard
Keyword(s):  
New Woman ◽  
Chinese Woman ◽  
Sexual Morality ◽  
Sexual Liberation ◽  
Social Trends ◽  
The New Woman ◽  
Competing Models ◽  
Political Conditions ◽  
Over Time

This case study of Republican China’s most widely read women’s periodical, The Ladies’ Journal (Funü zazhi), argues that the New Woman remained a highly contested ideal throughout the journal’s publication from 1915 to 1931. Editors and contributors endorsed competing models of modern femininity that shifted over time, shaped by volatile political conditions and social trends. With a focus on sexual morality, this article subjects normative visions of the modern Chinese woman, as depicted in The Ladies’ Journal, to a queer reading. By exploring the tension between widely circulated heteronormative discourses and their inherent slippages that revealed and fostered subversion, this article demonstrates that, rather than advocating for a clearly defined and radically new icon of sexual liberation, The Ladies’ Journal presented a vision of the New Woman that was capricious, contested, and in some ways conservative.


Transformative Events and Generational Memory: A Case Study Over Time in Lithuania

2013 ◽  
Vol 28 (2) ◽  
pp. 373-394 ◽  
Author(s):  
Amy Corning ◽  
Vladas Gaidys ◽  
Howard Schuman
Keyword(s):  
Over Time
Sign in / Sign up

Export Citation Format

Share Document