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Integration of real options into short-term mine planning and production scheduling

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Mining Science and Technology 2009年第5期19卷 674-678页

作者： KNIGHTS Peter crc Mining University of Queensland

Commodity prices have fallen sharply due to the global financial crisis. This has adversely affected the viability of some mining projects, including leading to the possibility of bankruptcy for some companies. These price falls reflect uncertainties and risks associated with mining projects. In recent years, much work has been published related to the application of real options pricing theory to value life-of-mine plans in response to long term financial uncertainty and risk. However, there are uncertainties and risks associated with medium/short-term mining operations. Real options theory can also be applied to tactical decisions involving uncertainties and risks. This paper will investigate the application of real options in the mining industry and present a methodology developed at University of Queensland, Australia, for integrating real options into medium/short-term mine planning and production scheduling. A case study will demonstrate the validity and usefulness of the methodology and techniques developed.

关键词： real options mine planning production scheduling economic uncertainty dump truck dispatch

A precise monitoring of snow surface height in the region of Lambert Glacier basin-Amery Ice Shelf,East Antarctica

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Science China Earth Sciences 2005年第1期48卷 100-111页

作者： I.Allison Australian Antarctic Division and Antarctic Climate and Ecosystems crc

The net surface snow accumulation on the Antarctic ice sheet is determined by a combination of precipitation, sublimation and wind redistribution. We present a one-year record of hourly snow-height measurements at LGB69 (70°50'S, 77°04'E, 1850 m a.s.l.). east side of Lambert Glacier basin (LGB), and 4 year record at G3 (70°53'S, 69°52'E, 84 m a.s.l.), Amery Ice Shelf (AIS). The measurements were made with ultrasonic sensors mounted on automatic weather stations installed at two sites. The snow accumulation at LGB69 is approximately 70 cm. Throughout the winter, between April and September, there was little change in surface snow height (SSH) at the two sites. The negative SSH change is due to densification at LGB69, and is due to both ablation and densification at G3. The strongest accumulation at two sites occurred during the period between October and March (accounting for 101.6% at LGB69), with four episodic increasing events occurring during 2002 for LGB69, and eight events during 1999-2002 for G3 (2 to 3 events per year). At LGB69, these episodic events coincided with obvious humidity 'pulses' and decreases of incoming solar radiation as recorded by the AWS. Observations of the total cloud amount at Davis station, 160 km NNE of LGB69, showed good correlation with major accumulation events recorded at LGB69. There was an obvious anti-correlation between the lowest cloud height at Davis and the daily accumulation rate at LGB69. Although there was no correlation over the total year between wind speed and accumulation at LGB69, large individual accumulation events are associated with episodes of strong wind (>7 m/s), we estimate drift snow may contribute to total SSH up to 35%. Strong accumulation events at LGB69 are associated with major storms in the region and inland transport of moist air masses from the coast.

关键词： Antarctica, Lambert Glacier basin, Amery Ice Shelf, accumulation, katabatic wind.

Palladium CO Sensor with Oscillatory Response

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稀有金属材料与工程 2006年第A3期35卷 194-196页

作者： L. Li W. Wlodarski S. Kandasamy D. B. Akolekar Z. G. Zhou School of Electrical ＆ Computer Engineering RMIT University Melbourne VIC 3001 Australia crc for microtechnology Hawthorn VIC 3122 Australia School of Applied Sciences RMIT University Melbourne VIC 3001 Australia State Key Lab of New Ceramics and Fine Processing Tsinghua University Beijing 100084 China

关键词： oscillation palladium carbon monoxide gas sensor

TIME-DEPENDENT MORPHOLOGY OF POLYETHYLENE-POLYPROPYLENE BLENDS

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Chinese Journal of Polymer Science 2002年第6期20卷 497-508页

作者： Robert A. Shanks Department of Applied Chemistry CRC for Polymers RMIT University Melbourne Victoria Australia

The effect of time-temperature treatment on morphology of polyethylene-polypropylene (PE-PP) blends wasstudied to establish a relationship between thermal history, morphology and mechanical properties. Polypropylene (PP)homopolymers were used to blend with various polyethylenes (PE), including high density polyethylene (HDPE), lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE), and very and ultra low density polyethylene(VLDPE and ULDPE). The majority of the blends were prepared at a ratio of PE:PP = 80:20, while blends of PP and LLDPEwere prepared at various compositions. Thermal treatment was carried out at temperatures between the crystallizationtemperatures of PP and PEs to allow PP to crystallize first from the blends. On cooling further, PE crystallized too. A verydiffuse PP spherulite morphology in the PE matrix was formed in some partially miscible blends when PP was less than 20%by mass. Droplet-matrix structures were developed in other blends with either PP or PE as dispersed domains in a continuousmatrix, depending on the composition ratio. The scanning electron microscopy (SEM) images displayed a fibrillar structureof PP spherulite in the LLDPE-PP (80:20) and large droplets of PP in the HDPE-PP (80:20) blend, providing larger surfacearea and better bonding in the LLDPE-PP (80:20) blends. This explains why the blends with diffuse spherulite morphologyshowed greater improvement in tensile properties than droplet-matrix morphology blends after time-temperature treatment.

关键词： Polypropylene and polyethylene blends Thermal history Spherulite Morphology Mechanical properties

Verification of Inverse Quench-Hardening Phenomena in Bearing Steel Specimens by Experiment and Computer Simulation

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材料热处理学报 2004年第5期25卷 465-470页

作者： Kyozo Arimoto Chuanrong Jin Shigeyuki Tamura Kiyoshi Funatani Mamoru Tajima Arimotech Ltd. Osaka JapanCRC Solutions Corp. Tokyo Japan CRC Solutions Corp. Tokyo Japan IMSTInst. Nagoya JapanKanagawa University Kanagawa Japan

The appearance of lower hardness at the surface than at the core after through-hardening of steels is known as "inverse quench-hardening." Pioneering work was performed in the 1970s by establishing a simple test procedure where cylindrical specimens were cooled by air and brine sequentially to produce the effect. This phenomenon was described in relation to the polymer quenching and its effect to the improvement in the fatigue strength of the steel in the 1990s. The hardening mechanism in the same specimens as the pioneering work was recently examined using a finite element simulation method. However, this work has not been completed for lack of experimental quenching cooling curves for the comparisons. In this study, the same experiments using 20mm diameter cylindrical specimens as those of the pioneering work were conducted to obtain cooling curves and hardness distributions for comparing simulated results. Experimental cooling curves showed a temperature recovery as predicted by the simulation. Also the inverse quench-hardening phenomena were found in the measured and simulated hardness distributions of the specimens.

关键词：热处理逆淬火硬化轴承钢计算机模拟

Feasibility of developing composite action between concrete and cold-formed steel beam

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Journal of Central South University 2013年第12期20卷 3689-3696页

作者： S.O.Bamaga M.Md.Tahir T.C.Tan S.Mohammad N.Yahya A.L.Saleh M.Mustaffar M.H.Osman A.B.A.Rahman Construction Research Centre (UTM-crc) Faculty of Civil EngineeringUniversiti Teknologi Malaysia

Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. Moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended.

关键词： cold formed steel beam composite shear connection thin-wall composite girder

TIME-TEMPERATURE-MISCIBILITY AND MORPHOLOGY OF POLYOLEFIN BLENDS

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Chinese Journal of Polymer Science 2000年第3期18卷 263-270页

作者： RobertA.Shanks GandaraAmarasinghe crc for Polymers Applied Chemistry RMIT University GPO Box 2476V Melbourne AustraliaCRC for Polymers Applied Chemistry RMIT University GPO Box 2476V Melbourne Australia

Miscibility and crystallization have been studied for polypropylene-polyethylene and polyethylene-polyethyleneblends. In the case of the polypropylene blends the composition of interest is 20% polypropylene. At this composition thepolypropylene has been found to be soluble in linear low density polyethylene but insoluble in high, low and very lowdensity polyethylenes. The miscibility has been concluded from the crystallization kinetics and polarised optical microscopywith a hot stage. Polyethylene-polyethylene blends have been formed from polymers with similar average branching contentbut where they have different melting temperatures. Important consequences are to introduce long branches into apolyethylene that only has short branches, and to modify the morphology of a polyethylenes so that haze, gloss and strainhardening are improved. Polyethylene blends must be developed after careful consideration of the branch content anddistribution within each of the constituents. It is not sufficient to simply blend polyethylenes, with the desired range ofproperties, without regard to the miscibility of the blend composition.

关键词： Polypropylene Polyethylene Blend Miscibility Thermal analysis Morphology Crystallization Melting

Environmental application and ecological significance of nano-zero valent iron

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Journal of Environmental Sciences 2016年第6期28卷 88-98页

作者： Biruck D.Yirsaw Mallavarapu Megharaj Zuliang Chen Ravi Naidu Centre for Environmental Risk Assessment and Remediation(CERAR) University of South Australia and CRC for Contamination Assessment and Remediation of the Environment(CRCCARE)

Toxicity studies considering both the bare and stabilized forms of zero valent iron nanoparticles（nZVI） could be timely, given that ecological risks identified are minimized through modification or with substitution of approaches in the synthesis, development and environmental application of the nanoparticles before succeeding to volume *** review is focused on the fate, transport and toxicological implications of the bare nZVI and surface modified particles used for environmental applications.

关键词： Nano zero valent iron Stabilized form of nZVI Toxicity

A longitudinal analysis of the U.S. Air Force Reserve Officers’ Training Corps physical fitness assessment

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Military Medical Research 2020年第2期7卷 166-173页

作者： Cameron SMackey Jason MDe Freitas Applied Neuromuscular Physiology Laboratory Oklahoma State University192 CRCStillwaterOK 74078USA

Background:The *** Force physical fitness assessment(PFA)is used to determine the overall fitness of their *** is currently unknown to what extent the PFA scores of Reserve Officers’Training Corps(ROTC)cadets are affected by mandatory physical *** purpose of this investigation was to longitudinally examine the PFAs of ROTC cadets over a four-year period,evaluate the results across class ranks,and evaluate the sensitivity of the classification of the ***:Air Force ROTC cadets performed the PFAs(abdominal circumference,1-min pushups,1-min sit-ups,and a 1.5-mile run)in both the spring(n=26)and fall(n=22)*** were compiled over a four-year period(Spring 2014–Fall 2017)and were performed in accordance with Air Force Instruction 36–2905.A oneway repeated measures ANOVA was performed separately for the fall and spring groups for each dependent variable across the 4 ***,a one-way between groups ANOVA was performed for each dependent variable during the time point(fall 2015;n=46)with the most recorded cadets for each class ***:Longitudinal assessments revealed a main effect of time(P=0.010)on abdominal circumference;cadets had a smaller abdominal circumference in their freshman year than in their senior year.A main effect of time(P=0.006)was also observed on sit-up quantity;cadets performed more sit-ups in their junior year than in their freshman *** between class ranks during the same year(between-subjects ANOVA)revealed a main effect of class rank on sit-up quantity(P=0.003);the freshmen completed fewer repetitions than the sophomores(P=0.018)and the juniors did(P=0.001).Conclusions:The results indicated that only the sit-up component showed differences between class *** findings suggest that the Air Force PFA may not be sensitive enough to detect changes in physical fitness or distinguish between class ranks regarding physical performance,even after years of *** limitation may b

关键词： Class ranks Fitness assessment Military Physical training ROTC