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71.
72.
This study concerns the correlation between burden and blast-induced vibrations in open-pit mines. For this purpose, two different
mines were studied. In these mines, the vibrations caused by explosions at burdens having widths ranging from 3 to 14 m were
measured from various distances. From the results, it was found for these cases that burden width has a significant impact
on vibrations. Consequently, it was proven that vibrations decrease as burden increases. 相似文献
73.
Dissolved oxygen is one of the most important water quality parameters. Aeration improves the water quality by maintaining good dissolved oxygen levels in water. Dissolved oxygen enters water by entrainment of air bubbles. A method of aeration that has become popular in recent years is the venturi aeration. In the present paper, experimental studies were conducted to investigate the effect of the location of the air hole in venturi tubes upon air injection. It was observed from the results that the location of the air hole playes a significant role for the air injection. The optimal air hole location that maximized the air injection in venturi aerators was determined. 相似文献
74.
The analysis of ground vibrations induced by bench blasting at Akyol quarry and practical blasting charts 总被引:3,自引:0,他引:3
Umit Ozer Ali Kahriman Mehmet Aksoy Deniz Adiguzel Abdulkadir Karadogan 《Environmental Geology》2008,54(4):737-743
Ground vibrations arising from excavation with blasting is one of the fundamental problems in the mining industry. Therefore,
the prediction of ground vibration components plays an important role in the minimization of environmental complaints. In
this study, 582 events were recorded during limestone production at a quarry (Akyol Quarry) during a period of time. The blasting
parameters of these shots were also carefully recorded. During the statistical analysis of the collected data, three predictor
equations proposed by the United States Bureau of Mines (USBM), Ambraseys–Hendron and Langefors–Kihlstrom were used to establish
a relationship between peak particle velocity and scaled distance described by these prediction equations. As a result of
this analysis, the most powerful relationship was determined and proposed to be used in this site. And also, this equation
was used in the derivation of the practical blasting charts specific to this site as a practical way of predicting the peak
particle velocity and maximum charge amount per delay for future blasting. 相似文献
75.
Abdullah Kaygusuz Cem Yücel Mehmet Arslan İrfan Temizel Keewook Yi Youn-Joong Jeong 《International Geology Review》2020,62(11):1406-1432
ABSTRACT The Eastern Pontides orogenic belt in NE Turkey hosts numerous I-type plutons of Eocene epoch. Here, we report new U–Pb SHRIMP zircon ages and in situ zircon Lu-Hf isotopes along with bulk-rock geochemical and Sr-Nd-Pb-O isotope data from the Kemerlikda??, Ayd?ntepe and Pelitli plutons and mafic microgranular enclaves (MMEs) to constrain their parental melt source(s) and evolutionary processes. U-Pb SHRIMP zircon dating yielded crystallization ages between 45 and 44 Ma for the studied plutons and their MMEs. The plutons range from gabbro to granite and have I-type, medium to high-K calc-alkaline, and metaluminous to slightly peraluminous characteristics. On the primitive mantle-normalized multi-trace-element variations, the plutons and their MMEs are characterized by signi?cant enrichment in LILE/HFSE. Chondrite-normalized REE patterns of the plutons and their MMEs are close to each other and show moderate enrichment with variable negative Eu anomalies. The studied plutons have fairly homogeneous isotope composition (87Sr/86Sr(i) = 0.70502 to 0.70560; εNd(i) = +0.9 to – 1.4; δ18O = +5.0 to +8.7‰, εHf(i) = – 2.2 to +13.5). The MMEs show medium to high-K calc-alkaline and metaluminous character. Although the isotope signatures of the MMEs (87Sr/86Sr(i) = 0.70508 to 0.70542; εNd(i) = +0.9 to ?1.1; δ18O = +5.8 to +8.0, εHf(i) = +4.3 to +10.4) are very similar to those of the host rocks. Fractionation of plagioclase, amphibole, pyroxene and Fe-Ti oxides played an important role in the evolution of the plutons. The isotopic composition of the studied plutons and MMEs are similar to I-type plutons derived from mantle sources. The MMEs show incomplete magma mixing/mingling, representing small bodies of mafic parental magma. The parental magma(s) of the studied plutons were generated from the enriched lithospheric mantle and then modified by fractional crystallisation, and lesser assimilation and mixing/mingling in the crustal magma chambers. 相似文献
76.
77.
For more than 20 years, the concept of near-fault pulse-like ground motion has been a topic of great interest due to its distinct characteristics, particularly due to directivity or fling effects, which are hugely influenced by the rupture mechanism. These unexpected characteristics, along with their effective frequency, energy rate, and damage indices, create a near-fault, pulse-like ground motion capable of causing severe damage to structures. One of the most common approaches for identifying ... 相似文献
78.
The oxidation of organophosphorus pesticides (OPPs), such as malathion and parathion, in aqueous solution was studied using conventional ozonation (O3), photolytic ozonation (O3/UV, O3/UV/H2O2), and heterogeneous catalytic ozonation (O3/TiO2/UV) processes. Experiments were performed in batch mode at laboratory scale and processes were compared in terms of disappearance kinetics. The best results of pesticide mineralization were obtained when TiO2 particles in combination with ozone (O3) and UV photolysis (λ = 254 nm) were applied. Decomposition of 99% of parent compounds were achieved in 10 min and oxon derivatives were completely removed in 30 min. The initial reaction rate increases linearly with increasing catalyst amount. Toxicity measurements of the treated solutions were carried out in order to evaluate the efficiency of the treatment methods. No detoxification was achieved for O3 and O3/UV applications. Heterogeneous photocatalytic ozonation was shown to be feasible for achieving complete decomposition of OPPs and their oxon intermediates. 相似文献
79.
Sukran Akkus Tulin Bal Nagihan M. Karaaslan Emre Yaman Ersin Kilinc Mehmet Yaman 《洁净——土壤、空气、水》2013,41(12):1229-1234
Five‐step sequential extractions were employed to fractionation of Ni, Cr and Cu in soil polluted by anthropogenic activities and determine the mobility of the metals. Twelve samples were collected on an agricultural area that was located near an airport and intercity roads in Elazig‐Turkey. Exchangeable, organically bounded, carbonate bounded, adsorbed species on Fe and Mn oxides and residual species (except silicates) of Ni, Cr and Cu were extracted into solution by using CaCl2, Na4P2O7, Na2EDTA, NH2OH–HCl and HNO3–H2O2, respectively. Mobile metal concentrations in fractions and total recoverable in soils were determined by using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Total recoverable Ni, Cr and Cu concentrations were in the range of 40–119, 45–126 and 23–72 mg kg?1, respectively. It was observed that total concentrations of metals in some of the samples were higher than the permitted values. The sum of the mobile percentages of metals was found to be lower than 50%. The Ni, Cr and Cu percentages for exchangeable species are in the ranges of 0.18–1.64, 0.03–0.59 and 0.42–2.53%, respectively. 相似文献
80.
Mehmet Yesiltas Timothy D. Glotch Steven Jaret Alexander B. Verchovsky Richard C. Greenwood 《Meteoritics & planetary science》2019,54(7):1495-1511
As of today, the Sariçiçek (SC) meteorite is the newest howardite and the only confirmed fall among the 17 known howardites. In this study, we present isotopic, infrared, and Raman data on three distinct pieces of the SC meteorite. Our oxygen isotopic measurements show that Δ17O values of the pieces are close to each other, and are in good agreement with other howardites, eucrites, and diogenites. The carbon isotopic measurements, which were conducted by combusting terrestrial contamination selectively at temperatures lower than 500–600 °C, show the presence of indigenous carbon in the SC specimens. The matrix of these specimens, investigated via infrared microspectroscopy, appears to be dominated by clinopyroxene/orthopyroxene, forsterite, and fayalite, with minor contributions from ilmenite, plagioclase, and enstatite. Carbon‐rich regions were mapped and studied via Raman imaging microspectroscopy, which reveals that both amorphous and graphitic carbon exist in these samples. Synchrotron‐based infrared microspectroscopy data show the presence of very little aliphatic and aromatic hydrocarbons. The SC meteorite is suggested to be originating from the Antonia impact crater in the Rheasilvia impact basin on 4 Vesta (Unsalan et al. 2019). If this is in fact the case, then the carbon phases present in the SC samples might provide clues regarding the impactor material (e.g., carbonaceous chondrites). 相似文献