SIGNIFICANCE: The pioneering work done in South Africa in developing radio communications technology for use underground in mines is summarised. Propagation took place, in the main, directly through the rock strata with incidental coupling into power cables, pipes, rails and other conductors. The research established the optimum frequencies for communications as well as the most appropriate antennas. Specialised radio equipment was developed for this task as constrained by the technology of the time. Size and weight were major constraints; ultimately, handheld equipment, using single-sideband modulation, was produced that functioned exceptionally well in numerous situations underground.

RESUMEN El rock peruano responde a los contextos económicos, políticos y sociales por los que atraviesa el país, y se conforma como un medio de expresión de la población en general. El objetivo de la investigación fue analizar las representaciones del sufrimiento amoroso y el sexo en las letras de las canciones de Pedro Suárez-Vértiz y Libido. Para ello, se aplicó el enfoque semántico pragmático propuesto por Molero (2003) compuesto por los niveles: lógico-conceptual, lingüístico y discursivo. Se determinó que, a nivel lógico conceptual, en ambos artistas las canciones sobre la congoja amorosa describen situaciones en las que el protagonista sufre por recuerdos o el fin de una relación; mientras que, sobre sexo, se identificó que la lírica describe actos sexuales. A nivel lingüístico, los dominios sobre sufrimiento amoroso en ambos artistas son: inmaterial y sentimientos; sobre sexo, el dominio común en ambos artistas es naturaleza. Por último, a nivel discursivo se identificó que en la letra de ambos artistas y en ambos temas predomina la narración de los hechos: en la lírica de Libido se empleó un lenguaje más literario y presentó un mayor número de metáforas para referirse al sufrimiento amoroso; mientras que la lírica de Suárez-Vértiz empleó un lenguaje más explícito y un mayor número de metáforas para referirse al sexo.

ABSTRACT Peruvian rock music responds to the economic, political, and social contexts the country is going through and is a means of expression for the general population. The objective of the research was to analyze the representations of amorous suffering and sex in the lyrics of the songs by Pedro Suárez-Vértiz and Libido. For this purpose, the pragmatic-semantic approach proposed by Molero (2003) was applied; it is composed of the following levels: logical-conceptual, linguistic, and discursive. It was determined that the songs about love pain of both artists, at the logical-conceptual level, describe situations in which the protagonist suffers from memories or the end of a romantic relationship, while, on sex, it was identified that the lyric describes sexual acts. At the linguistic level, the domains about amorous suffering in both artists are immaterial and feelings; about sex, the common domain in both artists is nature. Finally, at the discursive level, it was identified that in the lyrics of both artists and both themes, the narration of facts predominates; Libido's lyric used a more literary language and presented a more significant number of metaphors to refer to amorous suffering. In contrast, Suárez-Vértiz's lyrics used more explicit language and a greater number of metaphors to refer to sex.

SYNOPSIS The density, porosity, and strength of rocks are fundamental in the design of geo-engineering projects. Determining these properties requires the preparation of smooth core samples, which is usually impossible for soft rocks. Besides, only fragmented samples may be available in some projects. A method for predicting rock properties from rock particles such as drilling debris would therefore be useful. This study was undertaken to develop prediction equations for compressive strength (UCS), tensile strength (BTS), density, and porosity values from the crushability index (CI) obtained from rock fragments. The results showed that UCS, BTS, density, and porosity were strongly correlated with the CI. The physical characteristics and strength of rocks may be predicted with the help of the derived equations. The CI test is a valuable tool for estimating rock properties in drilling projects and in situations where core specimens are not available.

ABSTRACT The consumption of potassium (K) fertilizers in Brazilian agriculture exceeds the national production of this input by more than ten times, indicating the need for alternatives to reduce imports of these products. The objective of this study was to evaluate the performance of the remineralizing rocks phonolite and olivine melilitite as sources of K and other nutrients, as well as the effects of inoculation with Bacillus subtilis and Bacillus megaterium on the solubilization of these rocks in the soil. A greenhouse experiment was conducted using a randomized block design, with four replications, in a factorial arrangement consisting of three K sources (potassium chloride, phonolite, and olivine melilitite), three rates (150, 300, and 600 kg ha-1 K2O), with and without inoculant, and two controls without K (one with and one without inoculant). The experimental units consisted of pots containing 3 kg of soil and a strawberry plant grown for eight months. The treatment with olivine melilitite inoculated with rhizobacteria favored phosphate solubilization when applied the highest rate. Olivine melilitite remineralizer, alone or inoculated with rhizobacteria, increased K+ and Ca2+ contents in the soil when applied at the intermediate and highest rates (300 and 600 kg ha-1 K2O), highlighting this remineralizer as an alternative potassium source for plants.

RESUMO O consumo de fertilizante potássico pela agricultura brasileira supera em mais de dez vezes a produção nacional desse insumo, fato que indica a necessidade de alternativas para diminuir a dependência de sua importação. Diante disso, o objetivo deste trabalho foi avaliar o desempenho dos remineralizadores fonolito e olivina melilitito, como fonte de potássio e outros nutrientes, bem como o efeito da inoculação dessas rochas com as rizobactérias Bacillus subtilis e Bacillus megaterium, no incremento da solubilização destes materiais. O experimento foi realizado em casa de vegetação, sendo conduzido em delineamento blocos casualizados em arranjo fatorial, sendo três fontes (cloreto de potássio, fonolito e olivina melilitito), três doses (150, 300 e 600 kg ha-1 de K2O) com a presença ou ausência da inoculação, além de dois controles, sem adição de potássio, um com e outro sem inoculação, aplicados em 4 repetições. Foram avaliados os teores de potássio e outros nutrientes no solo. O tratamento com olivina melilitito inoculado com rizobactérias favorece a solubilização de fosfato na maior dose. O remineralizador olivina melilitito, isolado ou inoculado com rizobactérias aumentou os teores de K+ e Ca2+ no solo nas doses intermediária e máxima (300 e 600 kg ha-1 de K2O), destacando esse remineralizador como fonte alternativa de potássio para as plantas.

Flow Characteristics (FC) is one of the few methods developed for predicting long-term sustainable borehole yield of single wells in typical fractured rock aquifers. The FC method uses drawdown derivatives and subjective information on no-flow boundaries to estimate a sustainable borehole yield that should not cause the water level to drop below the main water strike (fracture) during long-term operations. Since its development, the FC method has been widely applied in many research and consulting projects. Two decades after its development, a review of its technical capabilities and limitations is necessary to enhance understanding among groundwater practitioners while building a platform for further improvements. The main strength of the method is its simplicity of use, its ability to protect the main water strike/fracture, and its lower susceptibility to the influence of aquifer heterogeneities because it does not require the input of aquifer storativity and transmissivity. The FC method also caters to the negative influence of impermeable boundaries, thereby enabling planning for different low-yield-causing scenarios. However, the major limitation is in using the subjective closed no-flow boundary without factoring aquifer storativity and the distance of the closed no-flow boundary from the pumping well. Under the influence of the closed no-flow boundary, the water must come from aquifer storage, hence the storativity and the size of the bounded aquifer are very critical parameters. It is therefore incorrect to factor in the influence of the closed no-flow boundary without considering its exact location. This limitation is reflected in the absence of criteria to determine the distance of the closed no-flow boundary from the pumping well for validating the FC results using numerical models. The FC method still needs validation using field operational data; other recommendations for future research are highlighted in the discussion.

A research project was carried out on a gold mine in the Vaal River region of South Africa (Witwatersrand Basin) to evaluate the effect of two particular aspects of rockbolt installation - the angle of inclination of the bolt relative to the orientation of the rock surface, and the protruding length of the bolt - on the mine's gully support system. A keyblock analysis approach indicated that these factors do not have an adverse impact on the stability of the strike gullies. This was confirmed by extensive empirical data collected from the case study mine. While safety is the primary concern, cost saving opportunities can be realized through reconsidering historically inherited support standards that are perceived to be correct and appropriate. The research described in this paper sets forth a practical approach, that is easy to implement and repeatable, to evaluate the role of rockbolts in stoping gullies.

ABSTRACT Studying the different ways in which the concept of volcanism is represented is crucial in the understanding of communities’ perception of the volcanic phenomena. In this contribution, 129 modern (2021-2023) depictions of volcanoes in Colombia between latitudes 0.82 and 5.96° N are described and classified into different contexts of use. Prehispanic depictions of volcanism are investigated in rock art sites (3 pictographs and 33 petroglyphs), and 15 distinct mythical narratives compiled and confirmed through interviews in the State of Nariño. We suggest that many of the rock art sites contain motifs that are reminiscent of the idea of volcanism, and that many of the folk tales include allusions to the volcanic concept. By collating the information contained in modern and older depictions, a link is established with the reality of the volcanic phenomena that shows how mutualism takes root between communities and volcanoes. The beneficial aspects derived from this relationship influence the perception of volcanic hazards in the region.

RESUMEN El estudio de las diferentes maneras mediante las cuales se representa el concepto de volcanismo es crucial en el entendimiento de la percepción de los fenómenos volcánicos. En este trabajo, un grupo de 129 representaciones modernas (2021-2023) de volcanes en Colombia entre las latitudes 0,82 y 5,96° N es descrito y clasificado en diferentes contextos de uso. Representaciones prehispánicas de volcanismo fueron investigadas en sitios de arte rupestre (3 pictógrafos y 33 petroglifos) y 15 diferentes narraciones míticas compiladas y confirmadas con entrevistas en el Departamento de Nariño. Muchos de los sitios de arte rupestre contienen motivos que son reminiscentes de la idea de volcanismo, y muchos de los mitos y leyendas contienen alusiones al concepto de volcán. Al agrupar la información contenida en las representaciones modernas y viejas, se establece un vínculo con los fenómenos volcánicos que muestra cómo este mutualismo se arraiga entre las comunidades y los volcanes. Aspectos benéficos derivados de esta relación es probable que influencien la percepción de las amenazas volcánicas en la región.

Resumo Efeito da Inclinação na Estrutura de uma Floresta do Domínio Mata Atlântica no Sul do Brasil. A composição da paisagem em mosaico de fragmentos florestais localizados em encostas altas, solos rasos dificultam as interações ecológicas e a sobrevivência de espécies vegetais. Este estudo teve como objetivo mostrar em um ambiente com essas características o efeito do gradiente ambiental relacionando o solo, a declividade e a vegetação de um fragmento de Floresta Estacional Semidecidual Montana. A estrutura da floresta foi amostrada em 12 parcelas retangulares contínuas, com 30X20m, totalizando 0,72ha. As amostras de solo foram coletadas por perfuração a cada 20m ao longo do divisor hidrográfico e abertura de três trincheiras usadas como locais de amostragem de solo para determinação in situ da cor do solo, horizonte e nutrientes. Os horizontes foram classificados como O/A/Cr na rocha alterada com presença marcante de cascalhos, e o solo foi classificado como Neossolo Litólico. A área apresenta declive acentuado, de 18,05% a 36,99%. A análise de regressão linear destacou o padrão oposto de riqueza de espécies em relação à inclinação e uma relação positiva entre a inclinação e o número de indivíduos mortos em pé. A riqueza de espécies também foi positivamente relacionada à distância das bordas da floresta. A avaliação evidenciou que a forte influência do declive e das atividades antrópicas no remanescente florestal são fatores comuns a diversos remanescentes de altitude, e pequenas ações de conservação podem garantir sua manutenção.

Abstract The mosaic landscape composition of forest fragments located on high slopes, shallow soils hinder ecological interactions and the survival of plant species. This study aimed to show, in an environment with these characteristics, the effect of the environmental gradient relating the soil, slope, and vegetation of a fragment of the Montane Seasonal Semideciduous Forest. The forest structure was sampled in 12 continuous rectangular plots, with 30 X 20m, totaling 0.72ha. Soil samples were taken by drilling every 20m along the hydrographic divisor and opening of three trenches used as soil sampling sites for in situ determination of soil color, horizon, and nutrients. Horizons were classified as O/A/Cr in the altered rock with a marked presence of gravels, and the soil was classified as Litholic Neosol. The area has a steep slope, from 18.05% to 36.99%. Linear regression analysis indicated an opposite pattern for species richness in relation to slope and a positive relationship between slope and the number of standing dead individuals. Species richness was also positively related to the distance from forest edges. The evaluation evidenced the strong influence of slope and human activities in forest remnant as common to several high-altitude remnants, and small conservation actions can guarantee their maintenance.

Abstract In civil engineering, the stability of many structures depends on the physical properties of the contact between the concrete seated on the rocky foundation surface. Usually, they are critical structures of great importance to society, such as: bridges, tunnels and dams. Thus, the shear behavior of rock-concrete joints is a key factor of the structural stability. The method of cohesive zones (CZM) allows to simulate the beginning of the formation of a crack and its propagation, without knowing the crack location or when it will start. Thus, in this work, a numerical model was developed capable of simulating the failure due to interfacial delamination of the contact between a structure formed by mortar seated on a rocky granite leaning surface. The calibration of the numerical model was performed using the experimental test results of simple compression on a block of rock in contact with the mortar by an inclined interface. The test was monitored using a high-resolution digital camera. The data were processed using the digital image correlation method (DIC) to obtain displacement data of the laboratory test. The DIC results were used to calibrate the nonlinear numerical model of the test using the bilinear method of cohesive zone in the rock-mortar interfacial contact elements. By a parametric analysis varying the maximum shear stress parameter of the contact cohesive elements, the bilinear law was adjusted (Maximum tensile stress and critical displacement and damage rate). Indirectly, the rate of release of energy of critical deformation from the rupture of the contact was also estimated.

Resumo Na engenharia civil, a estabilidade de muitas estruturas depende das propriedades físicas do contato entre o concreto assentado na superfície rochosa de fundação. Geralmente são estruturas críticas e de grande importância para a sociedade, tais como: pontes, túneis e barragens. Assim, o comportamento ao cisalhamento das juntas rocha-concreto é um fator chave da estabilidade estrutural. O método das zonas coesivas (MZC) permite simular o início da formação de uma fissura e a sua propagação, sem saber a localização da fissura ou quando esta irá começar. Assim, neste trabalho foi desenvolvido um modelo numérico capaz de simular a ruptura por descolamento interfacial do contato entre uma estrutura formada por argamassa assentada sobre uma superfície inclinada de granito rochoso. A calibração do modelo numérico foi realizada através dos resultados de ensaios experimentais de compressão simples sobre um bloco de rocha em contato com a argamassa por uma interface inclinada. O teste foi monitorado por meio de uma câmera digital de alta resolução. Os dados foram processados utilizando o método de correlação de imagens digitais (CID) para obtenção dos dados de deslocamento do ensaio laboratorial. Os resultados do método CID foram utilizados para calibrar o modelo numérico não linear do ensaio utilizando o método bilinear de zona coesiva nos elementos de contato interfacial rocha-argamassa. Através de uma análise paramétrica variando o parâmetro de tensão cisalhante máxima dos elementos coesivos de contato, determinou-se a lei bilinear ajustada (tensão máxima de tração, deslocamento crítico e taxa de dano). Indiretamente, também foi estimada a taxa de liberação de energia de deformação crítica proveniente da ruptura do contato.

Abstract As dams play a very important role in the optimum use of water resources, it is very important to keep them stable and the water stored in the reservoir. It is particularly important to investigate how water moves through rocks and the permeability and quality of the rock mass in structures like dams. Therefore, one of the issues considered in dam stability is monitoring the quantity of leaks. In this research, the engineering geological and geotechnical parameters of the rock mass for the construction of the Kurit Dam located in the city of Tabas in eastern Iran were evaluated. Initially, following the determination of geotechnical parameters, the engineering classification of the rock mass of the study area was carried out. In addition, in order to study and trace the water evacuation routes of the dam construction, two parameters of the RQD and Lugeon were studied and modelled. Analyses have been conducted to examine the permeability and rock quality index in three parts of the left and right abutment, the dam's axis and reservoir with geostatistics and kriging methods. Three-dimensional model of the construction of the Kurit dam was presented and the results were analyzed. Based on the results, the quality of the rock mass in the right and left abutments is arguably better than the dam axis and reservoir. Additionally, as the depth increases, the permeability decreases and the permeability is higher at shallow depths. The highest level of permeability is located at the surface and near the B H 4 borehole.

BACKGROUND: Mining of crushed stone for use in construction is among the various anthropogenic activities in the Eastern Cape province in South Africa that alter natural landscapes. However, little is known about the impact of these activities on arthropods and soil chemical properties. OBJECTIVES: We investigated the effect of distance (5, 30, 50 and 70 metres) from the mining sites on species richness, abundance and composition of surface-active arthropods, as well as composition and concentration of soil chemical properties (soil pH, calcium, magnesium, phosphorus and zinc. METHODS: The study was conducted at two mining sites in Nyandeni Local Municipality within the O.R. Tambo District Municipality that were commissioned in 2014. Arthropods were sampled using pitfall traps and thereafter sorted into morphospecies, while an auger was used to collect soil samples. Permutational multi-variate analysis was used to compare the composition of the arthropods and soil chemical properties among distances from the mining activities, while arthropod species richness and abundance, as well as concentrations of soil chemical properties, were analysed using the one-way analysis of variance or Kruskal-Wallis test. RESULTS: Arthropod species richness, abundance and composition were not influenced by distance from mining activities. Although among soil chemical properties, mining activities altered the concentration of zinc only, we found dissimilarities in soil composition between the sampling point at the edge of the mining activities and sampling points that were away from the mining sites. CONCLUSION: We found no evidence of the impact of crushed stone mining on surface-active arthropods; however, our study revealed a negative impact of crushed stone mining on soil chemical properties.

Resumen El presente trabajo muestra la evolución del fenómeno rock en el contexto internacional de los últimos 70 años. El objetivo consiste en analizar su papel como herramienta de protesta y expresión de descontento social que se extendió por todo el planeta gracias a multitud de artistas y grupos que han personificado el anhelo de libertad de la juventud en cada generación. Se describen en paralelo los grandes elementos que conforman el orden económico internacional imperante y los hitos fundamentales del rock desde su nacimiento. De este modo, se comprueba que este fenómeno social que va más allá del género musical ha servido de altavoz como denuncia ante los grandes acontecimientos económicos, sociales y políticos, especialmente para la juventud.

Abstract This work shows the evolution of the rock in the international context of the last seventy years. The objective is to study its role as a tool of protest and expression of social discontent that spread throughout the planet thanks to a multitude of artists and groups who have embodied the desire for freedom of the youth in each generation. The great elements that make up the international economic order and the fundamental milestones of rock since its birth are described in parallel. In this way, it will be shown that this social phenomenon that goes beyond the musical genre has served as a speaker of complaint against the great economic, social, and political events, especially for the youth.

SYNOPSIS The fracturing and movement of rock that occurs in the vicinity of a stemmed borehole charge in open pit mining operations are described by examining the effects of the emitted stress waves - shock and elastic - and the expansion of high-pressure detonation product gases. Three principal modes of momentum transfer to fractured rock are identified, all linked to gas expansion work. This work can be delivered radially (burden), axially (stemming), and in the collar zone (cratering). Flyrock is generated under unusual combinations of blast parameters and rock properties. Although infrequent and seldom predictable, the generation of flyrock can nonetheless be interpreted and modelled in terms of the principal mechanisms of rock projection described in this study. The physical processes underlying these principal mechanisms are identified and will permit the development of predictive models for flyrock velocities.

Abstract The proposed approach is based on the fact that the circulation and movement of people rock art landscape through space, and their relationship with it and with the things found there, is largely human related to certain factors that do not respond to economic ends. Now, is it possible to get circulation to know these factors? By considering that things have agency, although when related to throughout space people (Alberti2016; Van Dyke 2015), we propose a preliminar methodology to try to answer etnohistory and this question through, mainly, rock art from Aldea Beleiro. Approaching this materiality oral sources complementarily with historicalsources, toponymy, interviewswith residentsand otherUnes of archaeological evidence, it is concluded that the incorporation of these themes can enrich the discipline and the interpretations about how people circulated through the landscape, and how certain symbolic factors could affect the ways of perceiving and inhabiting it. The proposed methodology integrates different Unes of analysis, with the ultimate goal of generating a decolonial and respectful understanding of a past that is spatially, temporally and identitarily far from the majority of those who build this discipline.

Resumen El abordaje aquí propuesto se basa en que la circulación y el movimiento de las personas a través del espacio, y su vínculo con éste y con las cosas que allí se encuentran, está relacionado en gran medida con ciertos factores que no responden a fines económicos. Ahora bien, ¿esposible acercarse a estos factores? Entendiendo a las cosas como poseedoras de agencia, aunque siempre en tanto se encuentren en relación con las personas (Alberti 2016; Van Dyke 2015), se propone una metodología preliminar para intentar responder a esta pregunta a través de, principalmente, las representaciones rupestres de la localidad de Aldea Beleiro. Utilizando complementariamente esta materialidad con fuentes históricas, toponimia, entrevistas a pobladoresy, otras líneas de evidencia arqueológica, se concluye que la incorporación de estas temáticas puede enriquecer a la disciplina y a las interpretaciones acerca de cómo la gente circulaba por el paisaje, y cómo ciertos factores simbólicos podían afectar la manera de percibirlo y habitarlo. La metodología propuesta integra distintas líneas de análisis, con el fin último de generar un entendimiento decolonial y respetuoso de un pasado que se encuentra espacial, temporal e identitariamente lejos de la mayoría de quienes construimos esta disciplina.