955 resultados para Coal mines and mining


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Tuta absoluta (Meyrick) è un lepidottero originario dell’America meridionale, infeudato a pomodoro e ad altre solanacee coltivate e spontanee. Con l’attività trofica le larve causano mine fogliari e gallerie nei frutti, con conseguenti ingenti danni alle colture. T. absoluta è stato segnalato per la prima volta in Italia nel 2008 e in Piemonte nel 2009. Pertanto le ricerche sono state condotte per rilevarne la distribuzione in Piemonte, studiarne l’andamento di popolazione in condizioni naturali e controllate, e valutare l’efficacia di differenti mezzi di lotta al fine di definire le strategie di difesa. Il monitoraggio, condotto nel 2010, ha evidenziato come T. absoluta sia ormai largamente diffuso sul territorio regionale già pochi mesi dopo la segnalazione. L’insetto ha mostrato di prediligere condizioni climatiche più miti; infatti è stato ritrovato con maggiore frequenza nelle aree più calde. Il fitofago ha raggiunto densità di popolazione elevate a partire dalla seconda metà dell’estate, a ulteriore dimostrazione che, in una regione a clima temperato come il Piemonte, T. absoluta dà origine a infestazioni economicamente rilevanti solo dopo il culmine della stagione estiva. Per definire le strategie di lotta, sono state condotte prove in laboratorio, semi-campo e campo volte a valutare la tossicità nei confronti del lepidottero di preparati a base di emamectina benzoato, rynaxypyr, spinosad e Bacillus thuringiensis Berliner. In campo è stata verificata anche l’efficacia del miride dicifino Macrolophus pygmaeus (Rambur), reperibile in commercio. In tutte le prove, è stata riscontrata una maggiore efficacia di rynaxypyr ed emamectina benzoato. In campo M. pygmaeus ha mostrato difficoltà d’insediamento ed è stato in grado di contenere efficacemente il fitofago soltanto con bassi livelli d’infestazione. Per contro è stata costantemente osservata la presenza naturale di un altro miride dicifino Dicyphus errans (Wolff), che in laboratorio ha mostrato di non essere particolarmente disturbato dalle sostanze saggiate.

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A supply of so-called "copper pitch" ore was received by the Montana Bureau of Mines and Geology in response to a request by them from a resident of Kalispell, who had previously sent a specimen to the Bureau for a mineralogical analysis. Since this material was little known and had apparently received but little study under a reflec­ting microscope, it was thought that such a study might throw some light on the mineralogical and chemical composition of the material.

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In this issue...Mines Hockey, Ed Simonich, Faculty Wives Club, convocation, Mineral Research Center, Drama Club, Memoir 36, Montana Bureau of Mines and Geology

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This investigation assessed the applicability of Dr. William Haddon’s strategies for controlling hazards involving materials-handling operations in industrial and mining workplaces. Published over 20 years ago, Haddon’s strategies purport to include all strategies for preventing and mitigating harm to people, property, and the environment. Students in an undergraduate class were assigned to find tactical examples of each of Haddon’s strategies applicable to material handling. Haddon’s tenth strategy involving medical care and rehabilitation was not included. Their classifications were analyzed to identify points of confusion as well as points of general agreement. Students found numerous tactics for strategies involving engineering and behavioral strategies. Fewer tactics were identified for strategies involving damage control through effective and timely response.

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In this issue...Engineering Days, Mine Rescue and First Aid, Chemistry Department, Mineral Club, Anderson-Carlisle Society, Honor Roll, Continental Oil Company, Intramural basketball

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In this issue...M Days, beard contest, Anderson - Carlisle Society, Honor Roll, South Africa, Magma, International Club, First Aid, Bob Hauck, Continental Oil Company, Montana Power

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in this issue...Sweetheart Swirl Dance, R J Trio, Air Force Base, Civil Rights, Bill Barry's Boxing Club, International Club, Donald E. Mahagin, Main Hall

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General information on talc, including foreign and United States occurrences, origin, and uses is covered. Montana deposits are discussed in greater detail as to location, geology, mineralogy, and mining. Studies of talc by petrographic and x-ray methods and an experiment to determine the porosity are described and discussed.

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During winter 2013, extremely high concentrations (i.e., 4–20 times higher than the World Health Organization guideline) of PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm) mass concentrations (24 h samples) were found in four major cities in China including Xi'an, Beijing, Shanghai and Guangzhou. Statistical analysis of a combined data set from elemental carbon (EC), organic carbon (OC), 14C and biomass-burning marker measurements using Latin hypercube sampling allowed a quantitative source apportionment of carbonaceous aerosols. Based on 14C measurements of EC fractions (six samples each city), we found that fossil emissions from coal combustion and vehicle exhaust dominated EC with a mean contribution of 75 ± 8% across all sites. The remaining 25 ± 8% was exclusively attributed to biomass combustion, consistent with the measurements of biomass-burning markers such as anhydrosugars (levoglucosan and mannosan) and water-soluble potassium (K+). With a combination of the levoglucosan-to-mannosan and levoglucosan-to-K+ ratios, the major source of biomass burning in winter in China is suggested to be combustion of crop residues. The contribution of fossil sources to OC was highest in Beijing (58 ± 5%) and decreased from Shanghai (49 ± 2%) to Xi'an (38 ± 3%) and Guangzhou (35 ± 7%). Generally, a larger fraction of fossil OC was from secondary origins than primary sources for all sites. Non-fossil sources accounted on average for 55 ± 10 and 48 ± 9% of OC and total carbon (TC), respectively, which suggests that non-fossil emissions were very important contributors of urban carbonaceous aerosols in China. The primary biomass-burning emissions accounted for 40 ± 8, 48 ± 18, 53 ± 4 and 65 ± 26% of non-fossil OC for Xi'an, Beijing, Shanghai and Guangzhou, respectively. Other non-fossil sources excluding primary biomass burning were mainly attributed to formation of secondary organic carbon (SOC) from non-fossil precursors such as biomass-burning emissions. For each site, we also compared samples from moderately to heavily polluted days according to particulate matter mass. Despite a significant increase of the absolute mass concentrations of primary emissions from both fossil and non-fossil sources during the heavily polluted events, their relative contribution to TC was even decreased, whereas the portion of SOC was consistently increased at all sites. This observation indicates that SOC was an important fraction in the increment of carbonaceous aerosols during the haze episode in China.

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La necesidad de estudiar la presencia de metales pesados en el suelo radica en su impacto como indicador de contaminación ambiental. Se determinó la presencia de Cu, Zn, Pb y Cd en suelos donde se distribuyen especies vegetales en un corredor ecológico. Entre los municipios de Soledad de Graciano Sánchez y San Luis Potosí (México) fueron establecidos 30 puntos distribuidos en cinco prácticas dominantes de usos de suelo: agropecuario, residencial rural, comercio y servicios, residencial urbano y minero. Los muestreos se realizaron en cuatro épocas durante 2009 y 2010 (verano, otoño, invierno y primavera). Se encontró un efecto significativo del uso del suelo en cuanto a los niveles de Cu (p = 0,000), Pb (p = 0,043) y Cd (p = 0,010). En el caso del Zn, el uso del suelo (p = 0,000) y la estación (p = 0,059) fueron significativos. El uso del suelo minero mostró las mayores concentraciones de metales y el agrícola las menores. Los niveles de los cuatro metales se encuentran en el rango marcado como alto por la EPA y por otras fuentes técnicas. En el caso de Pb y Cd no rebasan los estándares NOM-147- SEMARNAT-SSA1. Estos resultados reflejan el potencial indicativo del uso del suelo en la evaluación de la calidad ambiental, sin embargo, se requiere continuar con un monitoreo de metales pesados en la zona.

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Evaluar la contaminación por metales pesados en los ecosistemas permite conocer la capacidad bioindicativa de especies vegetativas. El objetivo fue determinar la concentración de metales pesados en Prosopis laevigata, Acacia spp. y Schinus molle bajo el efecto de usos suelo y temporalidad. El área se sitúa en la colindancia de los Municipios de Soledad de Graciano Sánchez y San Luis Potosí fragmentada por usos de suelo: agropecuario, comercio y servicios, residencial urbano y minero. Fueron tomadas muestras de hojas de las tres especies en las estaciones de verano, otoño, invierno y primavera y se evaluó la concentración de metales pesados a través de la técnica de ICP-MS. Los análisis estadísticos indicaron niveles de Aluminio (Al) > Cinc (Zn) > Plomo (Pb) > Cobre (Cu) > Titanio (Ti) > Vanadio (V) > Arsénico (As) > Cromo (Cr) > Cadmio (Cd) > Cobalto (Co). Los elementos Al, As, Cd, Cr, Pb y Ti presentaron niveles por encima del umbral normal en vegetación. El uso de suelo tuvo efecto significativo con Al, Ti, Cd, As y Pb; los árboles ubicados en los usos de suelo minero, comercio y servicios tuvieron la mayor concentración. La especie tuvo efecto significativo con Al y Pb siendo Acacia spp. el que presentó la mayor capacidad de acumulación. La temporada del año impactó significativamente en la acumulación de As, Cd, Co, Cu, Cr y Ti en las tres especies. La dinámica antropogénica de los diferentes usos de suelo genera partículas y residuos con metales pesados impactando en la disponibilidad y acumulación en las especies evaluadas. Se contribuye a evaluar el impacto ambiental en el sistema fragmentado recomendando dar continuidad a este tipo de estudios.