bluuebunny/crossref_metadata_2025 huggingface dataset:
Technological research on converting iron ore tailings into a marketable product
Authors: Mitov I. , Stoilova A. , Yordanov B. , Krastev D.
Published: July 2021

We present three technological scenarios for the recovery of valuable components from gangue, stored in the tailings dam at Kremikovtzi metallurgical plant in Bulgaria, into marketable iron-containing pellets. In the first approach the iron concentrate was recovered through a two-stage flotation process, desliming, and magnetic separation. In the second proposed process, the iron concentrate was subjected to four sequential stages of magnetic separation coupled with selective magnetic flocculation. The third route entails the not very common practice of magnetizing roasting, followed by selective magnetic flocculation, desliming, and magnetic separation. The iron concentrate was pelletized in a laboratory-scale pelletizer. Each technology has been assessed with regard to the mass yield of iron concentrate, the iron recovery. and the iron, lead, and zinc content in order to identify the most effective route.
Supplementary Mineral Resources and Mineral Reserves Reports: Readability and textual choice
Authors: Du Toit E. , Delport P.W.J.
Published: July 2021

Investing in a mining venture can be risky and stakeholders need transparent, unbiased reports to understand the Mineral Resources and Mineral Reserves a mining company holds. Readability and textual choice can be used consciously to manipulate perceptions, or it can be done unconsciously. This exploratory study investigates the readability and textual choice of supplementary Mineral Resources and Mineral Reserves Reports of companies listed on the Johannesburg Stock Exchange. The results indicate that narrative manipulation occurs in these reports through word choices that make the reports difficult to read, as well as specific narrative selections. This reduces the informational value of the reports. The results of the study will be useful to various stakeholders, such as mining company management, investors, investment specialists, financial analysts, and even employees and the general community, who all use these reports to make important decisions. It is also useful for the preparers of the Mineral Resources and Mineral Reserves Reports, Competent Persons, and other technical specialists to be aware of readability and that certain textual choices can affect the interpretation of these reports. It is recommended that bodies such as the JSE and the SAMREC and SAMVAL Code committees consider adding a plain language requirement to regulations, guidelines, and codes to ensure transparent, unbiased, and objective reports.
Copper slag as a potential source of critical elements - A case study from Tsumeb, Namibia
Authors: Lohmeier S. , Lottermoser B.G. , Schirmer T. , Gallhofer D.
Published: July 2021

At a time of resource consumption, it is important to study the chemical composition of mining and metallurgical wastes to prevent the dissipative loss of metals and metalloids from the mining value chain. In particular, the recovery of critical elements from wastes is an option to increase the resources of such materials that are economically significant and have an overall supply risk. In this paper we report on the chemical composition, in particular the critical element content, of granulated slag originating from historical smelting activities in the Tsumeb area, Namibia. Laboratory-based inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray fluorescence (XRF) analyses as well as portable X-ray fluorescence (pXRF) demonstrate that the slags are on average enriched in base metals (Cu 0.7 wt%, Pb 2.7 wt%, Zn 4.7 wt%), trace metals and metalloids (Cd approx. 50 mg/kg, Mo approx. 910 mg/kg) as well as critical elements (As approx. 6300 mg/kg, Bi approx. 3 mg/kg, Co approx. 200 mg/kg, Ga approx. 100 mg/kg, In approx. 9 mg/kg, Sb approx. 470 mg/kg). While metals and metalloids such as As, Mo and Pb can be determined reliably using pXRF instruments, the technique has inherent limitations in evaluating the contents of certain critical elements (Ga, Sb). However, there are positive correlations between the As, Mo, and Pb contents determined by pXRF and the Ga and Sb contents obtained through ICP-MS and XRF. Thus, quantitative pXRF analysis for As, Mo, and Pb allows calculation of Ga and Sb abundances in the slags. This work demonstrates that pXRF analysers are a valuable tool to screen smelting slags for their chemical composition and to predict the likely contents of critical elements.
A review of the role of underground measurements in the historical development of rock engineering in South Africa
Authors: Malan D.F. , Napier J.A.L.
Published: July 2021

This paper describes some important aspects associated with historical underground measurements in South African gold and coal mines. Deformation measurements were used to confirm the use of elastic theory to simulate the rock mass behaviour in the Witwatersrand gold mines in the 1960s. Although a prominent time-dependent component of stope closure was measured as early as the 1930s, it was ignored owing to the benefit of adopting elastic theory. Neglecting the time-dependent response of the rock for many decades resulted in important aspects such as the effect of mining rate, the effect of advance per blast, and the need for enhanced design criteria not being explored. Recent work is only now starting to address this gap in knowledge. In-situ measurements of large coal specimens in the 1960s and 1970s indicated that a linear formula may possibly be a better approximation of coal pillar strengths. This alternative formulation was never adopted, however, as the power law strength formula was already deeply entrenched in the industry at that stage. In spite of these apparent failures to continuously generate and adopt new knowledge, a key lesson learnt is that major advances in rock mechanics will not be possible without careful monitoring of the rock mass behaviour in experimental sites. Areas requiring further research, such as pillar strength formulae for the Bushveld Complex and enhanced design criteria for the gold mines, can only be developed using extensive underground monitoring programmes.
A critical investigation into spontaneous combustion in coal storage bunkers
Authors: Govender S. , du Plessis J.J.L. , Webber-Youngman R.C.W.
Published: July 2021

Spontaneous combustion (SC) is a cold oxidation reaction that generates heat, causing a temperature rise of the reactant and leading, with limited heat dissipation, to self-ignition of the reactant, which occurs without an external heat source. Although not limited to coal, the most significant hazard of SC are the fires that occur in coal mining operations around the world. These fires pose a serious risk to the safety of workers in the mines as well as adverse effects on the environment, and can affect the quality of life for current and future generations. We investigated the occurrence of SC in raw coal storage bunkers with the purpose of compiling a decision analyser for engineers designing or working with coal storage bunkers. Specific experts were interviewed from different backgrounds and companies, followed by field research at a coal mine. The important factors affecting the possibility of SC occurring were the type of coal supplied to the bunker, the mining practice, and physical conditions around the bunker. The information presented here will assist in reducing the SC risk in raw coal storage bunkers. These findings, together with the systematic decision analyser developed, will assist design engineers and mine personnel to take early preventative steps in managing SC. The decision analyser was tested for many different scenarios and gave good guidance on how to minimize and prevent SC in bunkers.
Density - A contentious issue in the evaluation and determination of Resources and Reserves in coal deposits
Authors: Roux L.
Published: July 2021

The initial evaluation of a coal deposit often raises uncertainty with regard to the accuracy of the reported Resources and Reserves. Reconciliation of results from mining and beneficiation with the original raw field data highlights deficiencies in original estimations. Credible Resource and Reserve estimation forms the basis on which an entire mining enterprise is motivated, initiated, funded, and established as a commercially viable proposition. This is required for sustainable extraction purposes and to support vital downstream industries such as power generation. Accurate determination of the density of the matrix of the material being evaluated is the key to credible values being obtained for Resources and Reserves. Losses between 15% and 20% of the Resource/Reserve can be realized if incorrect densities are applied to the tonnage derivation. Coal plies and particles have different relative densities, determined by the maceral composition, rank, and mineral and moisture content. These factors in turn contribute to the moisture, volatile matter, ash and carbon contents of a coal, which affect the overall density of the raw coal. More specifically, the relationship of ash to density and the effective matrix porosity were found to be critical in solving the greater majority of the problems in predictive calculations. A major deficiency identified is the inability to determine effective porosity, allowing absorption of adventitious moisture and altering the mass of the core sample. Although the volume of the raw material is altered through crushing, the change in mass after controlled air-drying, used with the original geometrical volume of the raw material, provides a credible air-dry density and allows the determination of the volumetric change related to effective porosity. This parameter can be validated through the evaluation of proximate ash using the ash-adjusted algorithm and a correction for the inherent moisture applied to also give a credible relative density value for an air-dried sample. A combination of theoretical, empirical, and reconciliatory evaluations of the available data, taken from the exploration phase through the mining process to final production, has shown that an integrated approach using the ash-adjusted density (AAD) methodology, in conjunction with other evaluative techniques, provides credible results with a considerably higher degree of accuracy than is currently possible.
Evaluation of the mechanical properties of wood-derived charcoal briquettes for use as a reductant
Authors: Makgobelele N.W. , Mbaya R.K.K. , Bunt J.R. , Leokaoke N.T. , Neomagus H.W.J.P.
Published: July 2021

Silicon Smelters consumes more than 80000 t/a of wood-derived charcoal as carbonaceous reductant in the production of silicon metal. More than 10% of this material is discarded as fines (<6 mm) generated due to abrasion during processing. Charcoal fine residues (<650 μm) and polyvinyl alcohol (PVA) binder were used in this study to produce mechanically strong charcoal briquettes for metallurgical application as carbonaceous reductant. The PVA binder was added in mass percentages of 1, 3, and 5 wt% to the charcoal fines. The compressive strength, abrasion resistance index (ARI), drop shatter resistance (SRI), and water resistance index (WRI) were measured as functions of curing for up to 7 days under atmospheric conditions, and the results compared with metallurgical grade coarse charcoal. The ash content of the produced briquettes was found to be high (6.6-8.0%) compared with the coarse charcoal (1-3%). The 3 and 5 wt% PVA-bound briquettes were found to be the strongest, with compressive strengths of 40 and 115 kg/cm2 respectively, with WRI values of 75 and 73% respectively. The produced briquettes were found to have lower ARI and SRI values compared to the coarse charcoal. Future work should include beneficiation of the fine charcoal discards prior to briquetting, and an increase in binder addition to above 6 wt% to improve the ARI and SRIn.
Evaluation of polymer binders in briquetting of coal fines for combustion applications
Authors: Botha D.L. , Leokaoke N.T. , Bunt J. R. , Neomagus H.W.J.P.
Published: July 2021

Coal briquetting traditionally makes use of high-dosage, nonpolymeric binders (such as coal tar pitch or molasses) or polyvinyl alcohol (PVA) at low dosages for the binding of fine and ultrafine coal. Due to constraints associated with the manufacturing and cost of PVA-bound briquettes, a novel polyacrylic binder was developed that could possibly be added in low dosages at room temperature. A set of formulations of two polyacrylic components (components A and B) was developed, from which an optimal binder mixture was determined. This formulation comprises 40wt.% component A and 10wt.% component B with a 0.04wt.% cross-linking additive, and the balance water. The uniaxial briquette compressive strength was used to obtain the optimal binder mixture. The binder mixture was added to the coal powder in dosages from 0.1 to 1.2wt.%. Mechanical tests and thermogravimetric analysis in an oxidized environment at a maximum temperature of 930°C were conducted. Binder-bound briquettes were compared to binderless briquettes and PVA-bound briquettes. Briquettes made from the polyacrylic formulation had uniaxial compressive strengths double that of the binderless briquette yield strength, as well as the minimum recommended compressive strength of 0.375 MPa. The organic binders did not affect the combustion of the briquettes, since the results compared well with the binderless briquettes. The polyacrylic formulation is considered to be a possible substitute for PVA in terms of mechanical and thermal properties and raw material cost.
Deposición convectiva rápida a escala nanométrica de materiales compuestos activos para la fabricación de transistores orgánicos de efecto de campo
Authors: Del Pozo Freddy G. , Mas-Torrent Marta
Published: July 2021

Transistores orgánicos de efecto de campo basados en un material compuesto han sido fabricados por medio de la técnica de deposición convectiva rápida. La fabricación fue llevada a cabo bajo condiciones ambientales (aire, luz y humedad). En todos los casos, los transistores fabricados muestran un claro comportamiento de efecto de campo con características de semiconductor tipo-p, y exhiben movilidades en el orden de 10-2 cm2/V.s, totalmente comparables con transistores obtenidos por evaporación térmica del mismo material activo. La técnica de deposición demuestra que se pueden obtener dispositivos con alta reproducibilidad y que en todos los casos muestran una baja tensión umbral de alrededor 1 V. Por lo tanto, se demuestra que la deposición convectiva rápida puede ser usada para la fabricación de transistores orgánicos de efecto de campo sobre áreas amplias, con indicadores de reproducibilidad entre dispositivos y alta estabilidad en condiciones ambiente.
Convergence and nuances of Net Neutrality in South America
Authors: Triviño Roberto D. , Franco-Crespo Antonio , Ochoa-Urrego Leonardo
Published: July 2021

The Internet has become the ultimate platform for convergence, closely associated with network, technology, and media, due to its open and nondiscriminatory architecture. Convergence in telecommunications is propelled by ideas, ideologies, and policies progressively and cyclically, bringing further technological advancement, market, business, and policy changes. As a response to convergence, net neutrality seeks to regulate the relationship between Internet service providers and users to avoid discriminatory practices and ensure the openness of the Internet as a platform for innovation, economic development, and access to information for all. The objective of this work is to analyze the development of convergence in the telecommunications sector and the progress of net neutrality policies in South America, with five specific cases using a qualitative empirical approach. Within the findings, we identify different approaches for legislating net neutrality, controversies concerning the levels of commitment to the principles, ambiguity for effective enforcement of the rules, and commercial arrangements that in practice violate net neutrality.
Apoyo a los subsistemas de talento humano, selección y reclutamiento a partir de un sistema experto. Caso de estudio
Authors: Matute-Pinos Karina , Bojorque-Chasi Rodolfo
Published: July 2021

La gestión de talento humano es un factor fundamental en el éxito de las organizaciones. La inclusión en el entorno laboral de las personas con discapacidad ha ayudado a potenciar sus cualidades y a aprovechar su talento. Muchos de los sistemas de gestión de talento humano carecen de directrices para el reclutamiento y selección de una persona con discapacidad, es por eso por lo que el presente trabajo muestra el estudio realizado a estos dos procesos indicando los factores que influyen en la asignación o no de un cargo, donde de cada candidato es considerando el nivel y tipo de discapacidad, nivel de estudios, experiencia, capacitación entre otros aspectos, enfocándose en la tarea de aplicar técnicas de aprendizaje supervisado que permitan clasificar a un candidato con discapacidad para un puesto de trabajo como apto o no y técnicas de aprendizaje no supervisado como el clustering que ayuda a definir patrones ocultos en los datos si los hubiera. El resultado obtenido del estudio presenta varias técnicas de clasificación y la selección de la más adecuada para el conjunto de datos en cuestión, igualmente mediante técnicas de aprendizaje no supervisado se determina cuántos clústeres representativos se identifican en los datos. No se busca que se integren las personas a través de las discapacidades, sino todo lo contrario, que se integren las personas por medio de la potencialidad de todas sus capacidades.
Insuficiencias del paradigma punitivo y beneficios de la justicia restaurativa, a propósito de la doctrina Parot y la Vía Nanclares
Authors: Perandones Alarcón María
Published: July 2021

A través del análisis de la tres sentencias que centraron el debate jurídico-político relativo a la idoneidad de la doctrina Parot (STS 197/2006, de 28 de marzo; STC 57/2008, de 28 de abril y STEDH Asunto Del Río Prada v. España, de 21 de octubre de 2013), así como del modelo de justicia restaurativa adoptado con posterioridad en los Encuentros de Nanclares, el presente trabajo expone algunas de las deficiencias y disfunciones del modelo penal punitivo y cómo, frente al mismo, el paradigma restaurativo supone importantes beneficios y ventajas no sólo para la víctimas del hecho criminal sino para el conjunto de la sociedad.
El impacto de la digitalización en la competencia comunicativa en lenguas extranjeras en la Educación Superior
Authors: Rodríguez Pérez Nieves , Heinsch Bárbara
Published: July 2021

La competencia comunicativa, tanto en lengua materna como en lenguas extranjeras, forma parte de las ocho competencias clave para el aprendizaje permanente. El objetivo de esta investigación consiste en describir los cambios metodológicos que afronta el docente en la enseñanza online a partir de la crisis sanitaria (COVID-19); analizar la manera en la que la creciente necesidad de digitalización influye en la adquisición de competencias comunicativas en lengua extranjera y explorar en las competencias que necesita el docente de idiomas para la enseñanza telemática. La metodología es de tipo cualitativo y etnográfico sobre las experiencias docentes en el entorno virtual. Los resultados se obtienen del estudio y análisis de diarios y entrevistas con 14 profesores de lenguas extranjeras acerca de sus experiencias en este contexto y 137 estudiantes. Se demuestra la dificultad de comprender y ejercitar la comunicación no verbal y de desarrollar la interacción en el aula que afecta al proceso de enseñanza-aprendizaje de lenguas extranjeras. Los resultados son similares a estudios realizados en universidades españolas y alemanas. Se concluye que existe falta de formación en la competencia digital del profesorado por lo que las universidades deberían incluirlo en los planes curriculares. Se sugiere un modelo de formación mixto, alternando la docencia presencial con la virtual.
Una propuesta para trabajar la competencia digital docente a través de Instagram y el Pensamiento Visual: el estudio de la sostenibilidad
Authors: Fernandez-Diaz Manuel , Robles-Moral Francisco Javier , Ayuso-Fernández Gabriel Enrique
Published: July 2021

La competencia digital docente debe incluir, además de la utilización de medios tecnológicos y redes sociales aplicados a la educación, la interpretación de la información audiovisual y la creación y difusión de contenidos digitales, entre otros aspectos. En el presente trabajo, partiendo de una realidad concreta de estudiantes del Grado de Educación Primaria de la Universidad de Murcia, se les propone la realización de una actividad didáctica centrada en la sostenibilidad usando Instagram. Para valorar el trabajo realizado por el alumnado, se diseñó una rúbrica específica que aunase el abordaje de la cuestión científica planteada junto al desarrollo del pensamiento visual como estrategia didáctica. Tras la realización de la actividad, los 15 equipos de trabajo que se crearon, generaron mas de 200 publicaciones con una interacción en torno a 1,400 personas. El 73,3% de los trabajos elaborados obtuvieron una puntuación superior a la puntuación establecida como aceptable. Entre las conclusiones, destacamos que los futuros docentes, nativos digitales, tienen capacidades de manejo y uso de las redes sociales y tienen conocimientos científicos suficientes para su futura labor docente, pero encuentran dificultades a la hora de aunar ambos aspectos.
From low cost plant HMW DNA extraction to MinION sequencing v1
Authors: Serret Julien , not provided marie.couderc , Mariac Cedric , Albar Laurence , Sabot Francois
Published: July 2021

This low cost protocol is efficient to extract high molecular weight DNA from several tropical plants to prepare LSK109 libraries for Nanopore sequencing. Pulsed-field gel electrophoresis reveals a DNA size range from 40 to 350 Kb for four species of rice, Paspalum, date palm and Ocotea obtusata. Sequencing on MinION Nanopore flow cells yielded from 3.3 to 25.3 Gb with reads N50 values ranging from 15.4 to 31.3 Kb.
Immunostaining of tissues from dogs with subcutaneous nerve stimulation v1
Authors: Kusayama Takashi , Wan Juyi , Yuan Yuan , Liu Xiao , Li Xiaochun , C Fishbein Michael , H Everett Thomas , not provided Peng-Sheng.Chen
Published: July 2021

Immunostaining of tissue sections from dogs with subcutaneous nerve stimulation.
Literatura y cultura de tradición oral de la comarca de El Barco de Ávila-Piedrahíta (Ávila)
Authors: Jaén Castaño María
Published: July 2021

Este trabajo presenta una recopilación de literatura de tradición oral de varias localidades de la comarca abulense de El Barco de Ávila-Piedrahíta (Mercadillo, El Mirón, Aldealabad del Mirón, Arevalillo, Martínez, Pascualcobo, Collado del Mirón y Becedillas), que apenas ha sido explorada desde el punto de vista de su patrimonio tradicional.
El corpus de materiales que se presenta en este libro se distingue de otras recopilaciones realizadas en la comarca por su carácter totalizador, puesto que atiende prácticamente a todos los géneros de la literatura de tradición oral, y por el modo sistemático y riguroso con que se ha realizado la encuesta y la edición filológica de los textos, que incluye informaciones lingüísticas, etnográficas y sociales que resultan necesarias para comprender el contexto cultural en el que se encuadran.
El corpus se acompaña del estudio de una selección de textos que realza el valor y la riqueza de los materiales registrados, con identificación de las fuentes y las concordancias con otras versiones y con referencia a los catálogos nacionales e internacionales de literatura oral. El trabajo incluye también un glosario.
Professionally Relevant Traits of the Heads of Correctional Facilities
Authors: Karpova G.S. , Cheremisova I.V. , Kovalchuk I.A.
Published: July 2021

The article is dedicated to the study of professionally relevant personality traits, abilities and orientations of the officials of correctional facilities, holding senior positions in comparison to those of their subordinates. The traits are an integral part of the psychological and educational component of their professional competence. They reflect the most general, invariant psychological characteristics which ensure the success in their professional performance irregardless of their function or position. The hypothesis was that officials holding senior positions possess the professionally relevant traits to a greater degree, than their subordinates do. The processing of the obtained data demonstrated that senior officers surpass their subordinates in a number of professionally relevant traits (communicative, intellectual, emotional and volitional qualities). This qualities can be viewed as the psychological foundation for the formation of the subject position in professional development. The results are integrated into prospective studies of the factors and conditions for professional and personal development of penitentiary personnel. They are also used in designing programs for fostering their professional competence.
Women in Penal Correction System: Personality Characteristics and Opportunities for Professional and Career Development
Authors: Tsvetkova N.A. , Kulakova S.V.
Published: July 2021

Presents the results of an empirical study of women employed in the penitentiary system. Seven techniques were used: the Big Five Personality Questionnaire (NEO Personality Inventory); Hall Emotional Intelligence Test (by Nicholas Hall); test E.Berne'; the diagnostic technique for the motivators of one's socio-psychological activity; the methodology for studying the style of one's behavioral self-regulation by V.I. Morosanova; self-rating of possibilities for one's professional development and career; expert evaluation of officer's personality by B.G. Bovin. The examined group of female officers is characterized by : a) mid-range values of the four "traits of a normal personality"; b) modest levels of "emotional intelligence"; c) structural personality disorders which complicate interpersonal communication; d) an ambition to succeed accompanied by a much less apparent will to power; e) an accentuated average style of behavioral self-regulation with the vitally important "modeling skill" as the leading component and the "self-dependence" trait as a "backward" one. Finally, recommendations were proposed to improve the work with the personnel in the penitentiary system.
Responsibility as a Professionally Significant Trait of an Officer of the Penal Correction System of the Russian Federation
Authors: Ezhova O.N. , Ushkov F.I.
Published: July 2021

This research work is aimed at studying the personality traits of the personnel of the penal correction system (PCS) using the 70-statement questionnaire Multidimensional-Functional Diagnostics of "Responsibility" by A.P. Pryadeyin. Second and fourth year students of Samara Law Institute of the Federal Penitentiary Service, as well as current staff members of correctional facilities of the penal correction system took part in the research work. The study analyzed the naturally-predetermined (operational) and lifetime-acquired (substantial) responsibility domains. The obtained results suggest that the expression degree of personality traits in the PCS personnel that are necessary for the formation of responsibility, is largely determined by age, work experience in the PCS and by gender differences. The results are of practical importance and can be used for the formation of responsibility of the PCS personnel in performance management both during education period and during professional activities.
Activity of free radical processes in oral fluid of patients with recurrent upper respiratory tract infections
Authors: Petrenko Tatiana S. , Novikova Irina A. , Denisova Olga V. , Devichenskiy Vyacheslav M.
Published: July 2021

Background: Upper respiratory tract infections occupy a leading position in the infectious pathology. According to the World Health Organization (WHO), up to 500 million people fall ill with acute respiratory infections in the world every year, of which 2 million people die from various complications. At the same time, a number of researchers note the lack of methods for clinical and laboratory assessment of the condition of patients with this pathology. Aims: To evaluate the parameters of free radical oxidation in oral fluid of patients with recurrent upper respiratory tract infections (RIURT). Methods: The study involved 64 apparently healthy people who suffered respiratory infections up to 2 times a year, and 85 patients with RIURT (4 or more times a year), who at the time of the study were in remission. The determination of the parameters of the pro / antioxidant systems was carried out using two methods (photometric: the content of lipid peroxidation products and the level of ceruloplasmin and luminol-dependent chemiluminescence (LDCL) were measured, making it possible to assess the complex interaction of two systems prooxidants and antioxidants). Results: The studies have demonstrated that, for most of the RIURT patients during remission, the levels of certain prooxidant components (diene conjugates, ketodienes, Schiff bases), as well as of an oral fluid antioxidant (ADS: ceruloplasmin) were elevated compared to the controls. At the same time, the LDCL parameters of oral fluid did not go beyond the reference interval, although they were changed relative to the median of the control group. This allows us to consider the observed fluctuations as a balance in the system of pro- and antioxidants. Conclusions. The use of oral fluid as a biological material for the assessment of the pro-/antioxidant system opens up new possibilities in the diagnosis of respiratory disease.
Media in crisis: Blowing hot and cold
Authors: Turner Ralph H.
Published: July 2021

abstract

A 3-yr content analysis of all items dealing with earthquakes in six major Los Angeles newspapers and a review of television and radio treatment of earthquake topics in the same period, coupled with periodic surveys of popular understanding and attitudes toward the earthquake threat following announcement of the southern California uplift (Palmdale Bulge), lead to the identification of four media problems that contributed to the often erratic treatment of earthquake threat. First is the problem of newsworthiness, determining when and how to feature discussions of the continuing earthquake threat in the absence of either dramatic events or mobilized public controversy. Second is the problem of finding sources to provide a steady flow of material for use in preparing news items, in the absence of well-organized interest groups, especially those concerned with individual, household, and neighborhood earthquake preparedness. Third is the dilemma of how to balance the needs for alarm and reassurance, shocking people out of lethargy into action on the one hand versus trying to minimize unproductive anxiety and community disruption on the other hand. The fourth problem is communicating science when nonscientific world views are prevalent and merged to the point of confusion with scientific world views in popular thinking.
Seismic risk for commercial buildings in Memphis
Authors: Nowak Andrzej S. , Rose Elizabeth L. M.
Published: July 2021

This paper deals with the evaluation of seismic risk for commercial buildings in Memphis, Tennessee.

The seismicity of the area is summarized, and commercial buildings are divided into categories with regard to parameters such as number of stories, year of construction, assessed value, total floor area, and structural type. The distributions of these parameters are presented in the figures.

During the study, over 15 buildings were examined on site by a team of experts to evaluate their seismic resistances. The quality of the design, materials, and construction was found to be surprisingly good, particularly in those structures built since 1900.

Seismic resistance is analytically evaluated for five buildings: a four-story reinforced concrete frame; a four-story steel structure with vertical trusses; a 13-story stell frame; and two multi-story reinforced concrete frames. The loadings from four sources are considered: EI Centro and Taft earthquakes in California (1940 and 1952, respectively) and the forces specified in the 1979 UBC and 1981 BOCA codes. Ratios of load to capacity are calculated. For each building considered, the expected percentage of damage is evaluated for the two earthquakes. The damage prediction is extended to all commercial buildings in Memphis.
On the determination of radiated seismic energy and related source parameters
Authors: Doornbos D. J.
Published: July 2021

The determination of radiated seismic energy on the one hand, and of source size and static stress drop on the other, depends in principle on a representation of different parts of the source spectrum. In practice with band-limited data from a sparse network, the required source parameterization is often the same. Spectral models parameterized by the source's central moments of degree zero and two are introduced as an approximation to the general representation of the amplitude spectrum in terms of the central moments of even degree. Phase spectra are not used, apart from polarity. These models are shown to simulate well the principal features of common circular and Haskell type of models, including the corner frequency shift of P waves with respect to S waves, and the relation between rupture velocity and maximum seismic efficiency. Spectral bandwidths and the determination of radiated energy and apparent stress are contrasted to time domain pulse widths and the determination of source size and static stress drop in these models. The consequences of a reduced number of source parameters are examined, in particular for circular models and point source approximations; in these cases, results for radiated energy can be obtained in closed form. The scaling of radiated energy with moment is assumed to be linear for simple sources, but in stochastic models of complex sources the scaling may be between linear and quadratic. A relatively large increase of radiated energy with moment would be accompanied by an underestimate of source size and an overestimate of stress drop. However, the determination of radiated energy may still be correct.
Some recentLgphase displacement spectral densities and their implications with respect to the prediction of ground motions in Eastern North America
Authors: Street R.
Published: July 2021

Lg phase displacement spectral density corner periods of recent earthquakes in central New Brunswick and central Arkansas are used to point out a potential source of dispersion in the relative scaling of eastern North American strong-motion data. The corner periods of one of the central New Brunswick and several of the larger central Arkansas earthquakes are atypical of other events of similar magnitude and seismic moment in the region.

The maximum far-field ground motion of an earthquake is a function of its corner period. Therefore, strong-motion data of earthquakes that exhibit atypical characteristics, such as a displaced corner period, are a source of dispersion in the scaling of that strong-motion data if plotted as a function of magnitude or seismic moment.
Food store disturbance as a seismic intensity indicator
Authors: Nason Robert
Published: July 2021

The disturbance of shelf items in food stores can be an useful system for the reliable determination of seismic intensity. The reliability of the food store intensity ratings results from the similarity of food stores at many different places. Also, the amount of disturbance in a food store is easily determined. Observations indicate that the food store disturbances are comparable to the Modified Mercalli intensity scale from less than intensity V to greater than intensity VII. The food store seismic intensity correlates well with the measurements of peak acceleration on nearby strong-motion instruments. With few exceptions, food store intensity V correlates with peak acceleration values of 0.01 to 0.04 g, intensity VI with 0.06 to 0.15 g, and intensity VII with 0.21 to 0.43 g. The disturbance of furniture and the involuntary fall of people are indicators that may be useful at higher levels of seismic intensity.
An optimum data editing technique for the reduction of noise in multi-channel geophysical data
Authors: Tyraskis P. A. , Jensen O. G. , Smylie D. E. , Linton J. A.
Published: July 2021

We develop a data editing method, for the optimum interpolation of multichannel time series containing time-coincident data gaps, in one, several, or all channels based upon the autoregressive data model. The method is applied to a set of very long-period seismic data recorded during the 19 August 1977 Indonesian earthquake, which shows several unassociated bursts of noise. Spectral analysis following editing and interpolation of the record indicates existence of systematic signals with periods higher than 1 hr and perhaps as long as 2 hr. The individual spectral peaks in this subseismic band have not been identified.
Time delays in geophysical consolidation problems
Authors: Nyland Edo , Uribe-Carvajal Antonio
Published: July 2021

The tectonic response of the lithosphere to loads applied over a period of years is one of the few relatively direct ways of measuring lithospheric mechanical properties. We discuss here a method for estimating gross permeability of shallow lithosphere if such a lithosphere can be modeled as a Biot solid.

Induced seismicity at artificial lakes sometimes lags the history of lake filling. Clearly this indicates the anomalous load takes some finite time to create a stress increment over the tectonic regime associated with the lake. Such delays may result from diffusion into inhomogeneous regimes, but intuitively it seems that the Biot consolidation theory ought to contain the physics required to produce delayed response in the simplest model, an isotropic half-space with arbitrary vertical layering. The response of such a half-space can be calculated most quickly from matrix solutions of first-order differential equations.

We explore here a consistent formulation for the physics of the problem and examine the relation between the rate of diffusion of changes on the boundary, the geometry of the boundary change, and the physical properties of the material. The resulting formulas can be used to estimate probable delays in response of the physical system. Unfortunately, the values of physical properties required to make such estimates are hard to obtain.
High-frequency seismic noise at Lajitas, Texas
Authors: M. C. Li Todd , Ferguson John F. , Herrin Eugene , Durham Howard B.
Published: July 2021

A preliminary analysis of high-frequency (1 to 20 Hz) ambient seismic noise at a very quiet site in southwest Texas is presented. At frequencies greater than 1 Hz, the displacement noise power decreases at a rate between f−4 and f−5. The ambient seismic noise is also characterized by persistent narrow-band peaks (Δf < 0.2 Hz) of unknown origin. The noise appears to be propagating at phase velocities 2.5 to 4 km/sec or greater which suggests higher mode surface or body waves. Estimates of coherence and degree of polarization of three-component array data indicate that the high-frequency ambient noise is relatively well organized over distances of at least 600 to 700 m for a single component but is relatively unorganized in a three-component sense. A principal result of this preliminary analysis is that the use of three-component, high-frequency (1 to 20 Hz) arrays at very quiet sites, coupled with three-component processors, may result in substantial improvement of the thresholds for detection and discrimination of weak seismic events.
Application of three-dimensional kinematic imaging to analysis of seismic reflection data from the Nevada Test Site
Authors: Wen Jing , McMechan George A.
Published: July 2021

Three-dimensional kinematic migration produces a “best-fit” migrated surface, in three-dimensions, of any chosen reflector. The data are the travel times of all observed reflections and diffractions produced by the reflector. Source/receiver configurations are arbitrary, but should be arranged to provide good spatial sampling of the reflector. Each observation contributes an ellipsoid containing all possible reflection points. From this family of ellipsoids, the optimal reflector surface (the envelope of the family) is estimated by use of a statistical imaging condition. The “best-fit” position and shape of the reflector surface is obtained by defining a regular (x, y) grid over the region of interest and estimating the reflector depth beneath each grid point from the distribution of ellipsoids that are present there. The imaging criterion is implemented at each grid point by convolution of a Gaussian with the vector of ellipsoid depths. The width of the Gaussian is chosen to correspond to the scale of the features one wishes to resolve in the image. For each grid point, the migrated image is located at the depth at which the convolution is a maximum.

The algorithm is applied to both synthetic and real data. The synthetic data are constructed by ray tracing in a known structure. The real data are from a seismic survey at the Nevada Test Site; here, a reflector is imaged and interpreted as the surface of a high velocity Paleozoic dolomite that is overlain by low-velocity tuffs.
Perspetivas sobre a participação da criança no ambiente educativo
Authors: Filipe Sandra , Silva Brigite , Gomes Ana
Published: July 2021

A participação das crianças tem vindo a assumir maior destaque nos discursos educativos. No entanto, a ligação entre discursos e práticas nem sempre é consistente. Este artigo incide, assim, sobre perspetivas e práticas de profissionais de educação relativas à participação da criança no processo de ensino-aprendizagem. Com uma metodologia qualitativa, suportada por entrevistas a quatro educadoras de infância e a cinco professoras do 1.º Ciclo do Ensino Básico, o estudo tem a finalidade de perceber as suas perspetivas sobre a participação da criança, de que modo a consideram na organização do ambiente educativo e que obstáculos encontram a essa participação. Os dados recolhidos evidenciam a importância reconhecida à participação das crianças no contexto educativo, no entanto, verificam-se diferenças nas perspetivas e nas práticas entre os profissionais. As educadoras de infância valorizam a participação através da escuta das suas motivações e necessidades, considerando a criança como sujeito ativo, apesar de pouco explícita a sua concretização. As professoras do 1.º CEB consideram que a participação do aluno consiste sobretudo na colocação de dúvidas e na resposta ao que é solicitado.
Inclusão de jovens e adultos com deficiência na educação pública do Ceará: uma incursão documental
Authors: Holanda Gerda , Pereira Marcelino
Published: July 2021

A inclusão de jovens e adultos com deficiência no sistema de educação pública do Brasil e a garantia de acesso a uma educação de qualidade e oportunidades para desenvolver suas habilidades é um desafio permanente. O objetivo deste estudo é compreender o processo de inclusão de jovens e adultos com deficiência na escola regular noturna do Ceará, a partir da análise de documentos que tratam da temática. A investigação constitue a primeira etapa ao macroprojeto de pesquisa intitulado Inclusão escolar de jovens e adultos com deficiência: experiências e possibilidades de participação plena na escola pública brasileira. O método de investigação baseia-se na pesquisa documental de fontes primárias, numa abordagem qualitativa, com foco nas políticas públicas que regem o processo de inclusão desses jovens. Os resultados evidenciam que a inclusão educacional envolve muito mais que a garantia de os alunos com deficiência estarem nas salas de aula regulares, pois a inclusão de jovens e adultos com deficiência implica uma ação conjunta que possibilite a construção de novos patamares educacionais. Indicam, também, que as políticas de inclusão do Estado vêm seguindo as diretrizes propostas na política nacional, em que a educação destas pessoas é um importante veículo de consolidação.
Modelos mentales en alumnado con TDAH: Competencias lectora y matemática
Authors: Valarezo Dolores , Vieiro Pilar
Published: July 2021

Los niños con trastorno por déficit de atención e hiperactividad (TDAH) presentan una alta comorbilidad con dificultades de aprendizaje de la lectura y de las matemáticas, y una baja capacidad en relación con la planificación, organización e inhibición de la respuesta, y el mantenimiento de la concentración en la tarea. En este contexto, el objetivo de este estudio transversal es analizar la influencia de los modelos mentales en tareas de resolución de problemas matemáticos, cálculo y procesamiento semántico. La muestra estaba integrada por un total de 304 alumnos de Educación Primaria, 152 de tercer curso y 152 de sexto; la mitad formaban el grupo TDAH y la otra mitad el grupo control. Como instrumento de medida del procesamiento semántico se utilizó el programa Gesmedición, y para evaluar la competencia matemática la prueba de Problemas Verbales Aritméticos (PVA). Los resultados mostraron diferencias significativas en eficacia a favor del grupo control. Los sujetos con TDAH de ambos niveles educativos se mostraron significativamente más eficaces en tareas de cálculo, siendo los niveles de eficacia más bajos los de resolución de problemas, invirtiendo el patrón en relación al control.
Análisis del impacto espiritual del turismo religioso en la experiencia turística: el caso del Camino Ignaciano
Authors: Álvarez Orozco María Angélica , Aulet Seranllonga Silvia
Published: July 2021

El turismo religioso es uno de los tipos de turismo más antiguos de la historia, así mismo, peregrinar fue uno de los primeros desplazamientos con fines no económicos que realizó el ser humano (Duda & Doburzyński, 2019). Es conocido como una forma de expresión o tradición cultural, un objetivo espiritual o un compromiso de fe. La presente investigación da cuenta del impacto y la transformación espiritual que experimentan los turistas al emprender el Camino Ignaciano como un itinerario turístico y religioso. El estudio se realizó mediante análisis cualitativo y codificación de entrevistas aplicadas durante la peregrinación. Se analizaron 95 entrevistas semiestructuradas en la modalidad de 12, 16 y 30 días de peregrinación entre el 2015 y 2019. Ignacio de Loyola sufrió gran parte de su conversión en medio de una peregrinación que emprendió desde Loyola hasta Manresa, recorriendo más de 640 km. Al llegar a Manresa una de sus mayores obras dio fruto, la que hoy en día es base de la espiritualidad ignaciana alrededor del mundo y piedra angular del peregrinaje, los ejercicios espirituales. Esta obra se fundamenta en el discernimiento y la entrega a Dios para descubrir el secreto de una vida en plenitud. La peregrinación, en definitiva, es una actividad de turismo religioso que hace parte del turismo cultural y que muy a pesar de sus erróneas atribuciones negativas, el turismo, desde sus diferentes especialidades, está contribuyendo a la transformación espiritual de jóvenes y adultos, rescatando vidas desde una de sus prácticas más antiguas, el peregrinaje.