105 research outputs found

    Toxic Gases in Mining

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    Rapid detection of causes of mining accidents leading to emergencies is to search the  efforts. Controlling fires and gas leaks provides an immediate approach to rescue work for fatalities or injuries and detecting who needs resuscitation outside the mine. Evacuation and recovery operations should be guided by continuous monitoring of the mine environment due to fire and explosion hazards. The main toxic gases in mines are carbon monoxide (CO) and carbon dioxide (CO2); flammable gases are methane (CH4), CO and hydrogen (H2); suffocating gases are CO2, nitrogen (N20) and CH4; and the toxic gases are CO, nitrogen oxides (NOx) and hydrogen sulfide (H 2 S)

    Trends in Underground Mining

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    In this document, we will talk through information collected on all trends in mining in the underground environment as much as what happens in the world as or new machinery America provides the highest mining production in underground mining. We often discover opportunities for improvement in both productivity and costs. Of all these methods, braking is not only the most common, but also offers the largest share of overall production, nearly 50 percent. These underground mining methods are often determined by the deposits and the economics of mining and are therefore somewhat beyond the control of the operator(Trends in underground mining for gold and base metals | McKinsey, s. f.

    Fortaleciendo la convivencia escolar, desde la ciencias naturales mediante los permacultivos con los estudiantes del grado segundo J.T. del colegio I.E.D. estrella del sur de la localidad 19

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    108 p. Recurso Electr?nicoEl presente proyecto se produce a partir de observaciones de campo, consecutivamente durante los a?os 2016 y 2017 en el Colegio I.E.D. Estrella Del Sur Sede, de la Localidad 19; como reto a contribuir a una formaci?n para la vida en paz, el cual nos lleva a desarrollar una investigaci?n de car?cter cualitativo, con el m?todo de AP (acci?n-participaci?n) siendo part?cipes de forma continua mediante los instrumentos empleados a partir del planteamiento de la siguiente pregunta problema ?Qu? estrategia implementar para fortalecer la convivencia desde las ciencias naturales con los estudiantes del grado segundo J.T en la I.E.D. Estrella del Sur de la localidad 19?,para la cual se dise?? y se dio aplicaci?n de los siguientes instrumentos metodol?gicos como la observaci?n , la entrevista y los talleres pedag?gicos, introduciendo la experiencia de los permacultivos. Por lo anterior, esta propuesta se basa en te?ricos de las ciencias naturales, convivencia escolar y procesos de permacultivos, que permitieron desarrollar una estrategia que contribuye al fortalecimiento de la convivencia en los diferentes contextos social, familiar y escolar, a trav?s de talleres pedag?gicos que llevaron a disminuir situaciones relacionadas con conductas agresivas, vocabulario inadecuado, poco cuidado del entorno y de los recursos naturales; adem?s disminuir las brechas que impiden el trabajo en equipo, la participaci?n y las acciones ciudadanas desde las alternativas aprendidas en cada experiencia, para fomentar una cultura de paz en la cotidianidad de participantes. Palabras clave: permacultivos, convivencia, did?ctica de las ciencias naturales.The present project is based on an exercise of field observations in the School I.E.D. Estrella Del Sur Headquarters, of Locality 19, which were made consecutively during the years 2016 and 2017, where a problem of school coexistence was evidenced, which leads us to develop a qualitative research, with the AP method (action-participation) from the approach of the following question problem What strategy to implement to strengthen the coexistence from the natural sciences with the students of the second grade JT in the IED Star of the South of locality 19 ?, for which the following methodological instruments were designed and applied, such as observation, interview and pedagogical workshops, introducing the experience of permacultures. Therefore, this proposal is based on theories of the natural sciences, school coexistence and permaculture processes, which allowed to develop a strategy that contributes to the strengthening of coexistence in different social, family and school contexts, through pedagogical workshops that led to decrease situations related to aggressive behaviors, inadequate vocabulary, little care of the environment and natural resources; also reduce the gaps that prevent teamwork, participation and citizen actions from the alternatives learned in each experience, to promote a culture of peace in the daily lives of participants. Keywords: permacultures, coexistence, didactics of the natural sciences

    Strategic Environmental Planning for Deep Seabed Mining in the Area

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    Discussions approximately an environmental control method for deep seabed mining in the Area had been underway for some the years. Both states and scientists have known for such an environmental control method. In 2018, the International Seabed Authority has followed its first 5-year strategic plan, masking all elements of its mandate. This article examines the brand-new strategic plan integrates factors of an environmental control method and what is probably missing. It demonstrates that even as a few overlaps exist, there are numerous key gaps left via way of means of the modern strategic plan which will be stuffed via the way of means of an environmental control method. To operationalize those desires and objectives, development ought to be measurable; thus, objectives are set, reviews are assessed, and suitable responses are awarded. Many control equipment and toots are relevant for accomplishing environmental desires. To date, the ISA has taken into consideration marine spatial making plans in large part across the modern exploration settlement blocks. Other factors of environmental control, which include the necessities for baseline studies, effect assessment, post-effect tracking, and the remedy of dangerous consequences and extreme damage want to be carried out to assist well-described environmental desires and objectives. We advocate that this making plans be done for scales largethan man or woman blocks, through a Strategic Environmental Management Plan, to make certain sustainable use of ocean assets throughout the Area

    Safety and Health in Mining

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    In the history of the mining sector, in its beginnings it faced very high levels of risks both safety and health. The data are limited to serious accidents, and these are mainly associated with falls from land, transport and machinery. Analysis of these data suggests that the leading causes of death tend to be the same as those of serious injuries, while disasters have a different profile. Over the past decade, mining disasters have been associated with explosions due to flammable gases, a fire on a conveyor belt, a flood of mud and water, and rock outbursts. Mandatory compliance with a company's safety, health and environmental regulations is a minimum and can be significantly improved by adding a long-term management planning and implementation process with a deeper cultural shift towards continuous improvement in safety and quality. Note that the purpose of integrating health and safety into other management systems is the need for health and safety management to be central, rather than an organizational objective

    Identificación temprana de síndrome de WHIM. Informe de un caso

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    Antecedentes: El síndrome WHIM corresponde a un error innato de la inmunidad innata e intrínseca, caracterizada por verrugas (Warts), hipogammaglobulinemia, infecciones y mielocatexis, por sus siglas en inglés.  Reporte de caso: Paciente masculino de 4 años, con neutropenia severa y linfopenia de células B desde el nacimiento, sin infecciones severas ni verrugas. El estudio de secuenciación genética informó la variante CXCR4 c.1000C>T (p.Arg334*), relacionada con el síndrome de WHIM. Conclusión: El diagnóstico de neutropenia severa desde el nacimiento debe incluir la búsqueda de errores innatos de la inmunidad, mediante estudios de secuenciación genética, especialmente en pacientes asintomáticos u oligosintomáticos. Palabras clave: Neutropenia; células B; inmunidad celular; CXCR4; WHIM

    Effect of the concentration of magnetite on the structure, electrical and magnetic properties of a polyester resin-based composite

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    Se reporta el efecto de la concentración de polvos de magnetita (Fe3O4) sobre las propiedades eléctricas y magnéticas de un material compuesto a base de resina de poliéster termoestable. Las muestras se elaboraron mediante el método de colado manual en concentraciones de: 60-40, 70-30, 80-20, 90-10 y 100-0 (% en peso), donde la fase mayoritaria es la resina y la minoritaria los óxidos de Fe3O4. La estructura cristalina se estudió usando la técnica de difracción de rayos X y la caracterización superficial tuvo lugar a través de la técnica de microscopía electrónica de barrido. Se midió la respuesta eléctrica por medio de curvas de polarización eléctrica en función del campo eléctrico y de resistividad eléctrica volumétrica a través de un electrómetro. La respuesta magnética se determinó mediante curvas de magnetización en función de la intensidad de campo magnético aplicado y en función de la temperatura. El análisis estructural indica que el porcentaje de cristalinidad aumenta a medida que se adiciona la concentración de Fe3O4 a las muestras. La caracterización eléctrica del material evidencia que la resistividad volumétrica disminuye con el incremento de magnetita, mostrando una transición aislante-conductor, con valores de la constante dieléctrica cada vez mayores. La caracterización magnética evidencia un aumento lineal de la magnetización de saturación y del momento magnético en función de la cantidad de magnetita adicionada a la matriz polimérica, mientras que la coercitividad evidencia comportamientos de materiales magnéticos blandos tanto en T˃TV como en T<TV, donde TV representa la temperatura de Verwey.This study reports the effect of the concentration of magnetite powders (Fe3O4) on the electrical and magnetic properties of a resin-based composite of thermoset polyester. The samples were prepared by the casting method at different concentrations: 60-40, 70-30, 80-20, 90-10 and 100-0 (% in weight), where the primary phase was resin and the secondary, Fe3O4 powders. The crystalline structure was studied using X-ray diffraction and surface characterization was carried out applying the scanning electron microscopy technique. The electrical response was measured by electric polarization curves as a function of the electric field; and the volumetric electrical resistivity, by an electrometer. The magnetic response was determined by magnetization curves as a function of temperature and intensity of the applied magnetic field. The structural analysis indicates that crystallinity increases as higher concentrations of Fe3O4 are added to the samples. The electrical characterization of the material reveals that the volumetric resistivity decreases as the content of magnetite increases. These reactions indicate an insulation-conductor transition with increasing dielectric constant values. The magnetic characterization presents a linear increase of the saturation of magnetization and magnetic moment as a function of the amount of magnetite added to the polymer matrix, whereas the coercivity shows behaviors of soft magnetic materials for T ˃ Tv and for T < Tv, where Tv represents the temperature of Verwey

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Improved risk stratification of patients with atrial fibrillation: an integrated GARFIELD-AF tool for the prediction of mortality, stroke and bleed in patients with and without anticoagulation.

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    OBJECTIVES: To provide an accurate, web-based tool for stratifying patients with atrial fibrillation to facilitate decisions on the potential benefits/risks of anticoagulation, based on mortality, stroke and bleeding risks. DESIGN: The new tool was developed, using stepwise regression, for all and then applied to lower risk patients. C-statistics were compared with CHA2DS2-VASc using 30-fold cross-validation to control for overfitting. External validation was undertaken in an independent dataset, Outcome Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). PARTICIPANTS: Data from 39 898 patients enrolled in the prospective GARFIELD-AF registry provided the basis for deriving and validating an integrated risk tool to predict stroke risk, mortality and bleeding risk. RESULTS: The discriminatory value of the GARFIELD-AF risk model was superior to CHA2DS2-VASc for patients with or without anticoagulation. C-statistics (95% CI) for all-cause mortality, ischaemic stroke/systemic embolism and haemorrhagic stroke/major bleeding (treated patients) were: 0.77 (0.76 to 0.78), 0.69 (0.67 to 0.71) and 0.66 (0.62 to 0.69), respectively, for the GARFIELD-AF risk models, and 0.66 (0.64-0.67), 0.64 (0.61-0.66) and 0.64 (0.61-0.68), respectively, for CHA2DS2-VASc (or HAS-BLED for bleeding). In very low to low risk patients (CHA2DS2-VASc 0 or 1 (men) and 1 or 2 (women)), the CHA2DS2-VASc and HAS-BLED (for bleeding) scores offered weak discriminatory value for mortality, stroke/systemic embolism and major bleeding. C-statistics for the GARFIELD-AF risk tool were 0.69 (0.64 to 0.75), 0.65 (0.56 to 0.73) and 0.60 (0.47 to 0.73) for each end point, respectively, versus 0.50 (0.45 to 0.55), 0.59 (0.50 to 0.67) and 0.55 (0.53 to 0.56) for CHA2DS2-VASc (or HAS-BLED for bleeding). Upon validation in the ORBIT-AF population, C-statistics showed that the GARFIELD-AF risk tool was effective for predicting 1-year all-cause mortality using the full and simplified model for all-cause mortality: C-statistics 0.75 (0.73 to 0.77) and 0.75 (0.73 to 0.77), respectively, and for predicting for any stroke or systemic embolism over 1 year, C-statistics 0.68 (0.62 to 0.74). CONCLUSIONS: Performance of the GARFIELD-AF risk tool was superior to CHA2DS2-VASc in predicting stroke and mortality and superior to HAS-BLED for bleeding, overall and in lower risk patients. The GARFIELD-AF tool has the potential for incorporation in routine electronic systems, and for the first time, permits simultaneous evaluation of ischaemic stroke, mortality and bleeding risks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF (NCT01090362) and for ORBIT-AF (NCT01165710)

    Two-year outcomes of patients with newly diagnosed atrial fibrillation: results from GARFIELD-AF.

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    AIMS: The relationship between outcomes and time after diagnosis for patients with non-valvular atrial fibrillation (NVAF) is poorly defined, especially beyond the first year. METHODS AND RESULTS: GARFIELD-AF is an ongoing, global observational study of adults with newly diagnosed NVAF. Two-year outcomes of 17 162 patients prospectively enrolled in GARFIELD-AF were analysed in light of baseline characteristics, risk profiles for stroke/systemic embolism (SE), and antithrombotic therapy. The mean (standard deviation) age was 69.8 (11.4) years, 43.8% were women, and the mean CHA2DS2-VASc score was 3.3 (1.6); 60.8% of patients were prescribed anticoagulant therapy with/without antiplatelet (AP) therapy, 27.4% AP monotherapy, and 11.8% no antithrombotic therapy. At 2-year follow-up, all-cause mortality, stroke/SE, and major bleeding had occurred at a rate (95% confidence interval) of 3.83 (3.62; 4.05), 1.25 (1.13; 1.38), and 0.70 (0.62; 0.81) per 100 person-years, respectively. Rates for all three major events were highest during the first 4 months. Congestive heart failure, acute coronary syndromes, sudden/unwitnessed death, malignancy, respiratory failure, and infection/sepsis accounted for 65% of all known causes of death and strokes for <10%. Anticoagulant treatment was associated with a 35% lower risk of death. CONCLUSION: The most frequent of the three major outcome measures was death, whose most common causes are not known to be significantly influenced by anticoagulation. This suggests that a more comprehensive approach to the management of NVAF may be needed to improve outcome. This could include, in addition to anticoagulation, interventions targeting modifiable, cause-specific risk factors for death. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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