79 research outputs found

    Role of Chloride on the Environmental Degradation of Micro-Alloyed Steel in Simulated Fuel Grade Ethanol Environment

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    In this study, micro-alloyed steel (MAS) material commonly used in the manufacture of auto parts and pipes was immersed in simulated fuel grade ethanol (SFGE) blends and its performance was evaluated. In order to determine the role of chloride on corrosion behavior, electrochemical measurement was conducted in low-conductivity ethanolic solutions in the absence of supporting electrolyte; also mass loss test was performed. Consistent with the mass loss and electrochemical test results, the effect of chloride on the degradation of MAS in the fuel ethanol environments can be classified from the least corrosive concentration to the highest as follows: 0 mg/L<32 mg/L<64 mg/L NaCl. Chloride increased the pitting tendency of MAS in E20, E40, and E80 blends

    Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

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    The Konkola deposit is a high grade stratiform Cu–Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper–cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irregular veins. The hypogene sulphide mineralogy consists predominantly of chalcopyrite, bornite and chalcocite. Based upon relationships with metamorphic biotite, vein sulphides and most of the sulphides in cemented lenses were precipitated during or after biotite zone greenschist facies metamorphism. New ή34S values of sulphides from the Konkola deposit are presented. The sulphur isotope values range from −8.7‰ to +1.4‰ V-CDT for chalcopyrite from all mineralising phases and from −4.4‰ to +2.0‰ V-CDT for secondary chalcocite. Similarities in ή34S for sulphides from different vein generations, earlier sulphides and secondary chalcocite can be explained by (re)mobilisation of S from earlier formed sulphide phases, an interpretation strongly supported by the petrographic evidence. Deep supergene enrichment and leaching occurs up to a km in depth, predominantly in the form of secondary chalcocite, goethite and malachite and is often associated with zones of high permeability. Detailed distribution maps of total copper and total cobalt contents of the Ore Shale formation show a close relationship between structural features and higher copper and lower cobalt contents, relative to other areas of the mine. Structural features include the Kirilabombwe anticline and fault zones along the axial plane and two fault zones in the southern limb of the anticline. Cobalt and copper behave differently in relation to these structural features. These structures are interpreted to have played a significant role in (re)mobilisation and concentration of the metals, in agreement with observations made elsewhere in the Zambian Copperbelt

    The IDENTIFY study: the investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer - a multicentre observational study

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    Objective To evaluate the contemporary prevalence of urinary tract cancer (bladder cancer, upper tract urothelial cancer [UTUC] and renal cancer) in patients referred to secondary care with haematuria, adjusted for established patient risk markers and geographical variation. Patients and Methods This was an international multicentre prospective observational study. We included patients aged ≄16 years, referred to secondary care with suspected urinary tract cancer. Patients with a known or previous urological malignancy were excluded. We estimated the prevalence of bladder cancer, UTUC, renal cancer and prostate cancer; stratified by age, type of haematuria, sex, and smoking. We used a multivariable mixed-effects logistic regression to adjust cancer prevalence for age, type of haematuria, sex, smoking, hospitals, and countries. Results Of the 11 059 patients assessed for eligibility, 10 896 were included from 110 hospitals across 26 countries. The overall adjusted cancer prevalence (n = 2257) was 28.2% (95% confidence interval [CI] 22.3–34.1), bladder cancer (n = 1951) 24.7% (95% CI 19.1–30.2), UTUC (n = 128) 1.14% (95% CI 0.77–1.52), renal cancer (n = 107) 1.05% (95% CI 0.80–1.29), and prostate cancer (n = 124) 1.75% (95% CI 1.32–2.18). The odds ratios for patient risk markers in the model for all cancers were: age 1.04 (95% CI 1.03–1.05; P < 0.001), visible haematuria 3.47 (95% CI 2.90–4.15; P < 0.001), male sex 1.30 (95% CI 1.14–1.50; P < 0.001), and smoking 2.70 (95% CI 2.30–3.18; P < 0.001). Conclusions A better understanding of cancer prevalence across an international population is required to inform clinical guidelines. We are the first to report urinary tract cancer prevalence across an international population in patients referred to secondary care, adjusted for patient risk markers and geographical variation. Bladder cancer was the most prevalent disease. Visible haematuria was the strongest predictor for urinary tract cancer

    ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration

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    Dolomitization of the Latemar buildup (Dolomites, northern Italy)

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    ABSTRACT This study focuses on the spatial distribution and genesis of dolomite in the Latemar Formation and the underlying Contrin Formation in the Latemar buildup (Dolomites, Northern Italy). The Contrin Formation is completely dolomitized. From this formation several dolomitized pipe-like structures up to 100 m in diameter occur that extend into the Latemar Formation. In addition large dolomite bodies (50-100 m) occur scattered. The origin of these massive dolomite structures and their relation to crosscutting mafic dikes and the nearby Predazzo Intrusion is a part of this ongoing petrographical, geochemical (stable C- and O-isotopes, Sr- & Mg-isotopes) and petrophysical (poroperm) study. Keywords: Dolomitization, Latemar, Predazzo Intrusionstatus: publishe
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