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By N. Campbell

"The fault under consideration follows a northerly trend past the west; side of the original settlement of Yell ow knife; which is situated 600 miles; north of Edmonton and 400 miles from the Northern Alberta Railway; terminus at Waterways; Alberta. The mining properties chiefly concerned; include the southern part of the Giant claims; on the east side of the fault; and the Con-Rycon-Demelt claims; on the west side 3 1/2 miles to the south.; Geological data were also obtained from the eastern part of the A.Y.E.; property; which lies south of the Giant claims; and from the Negus; Meg; Yellorex; and Kam properties; which are south and southeast of the ConRycon-; Demelt claims (see Frontispiece; also Fig. 5).Recognition of the major faults in the Yellowknife Bay area, including the West Bay fault, which appears to be the greatest, resulted from the work of A. W. Jolliffe (formerly of the Geological Survey of Canada) in 1935 and subsequent years. It has been stated with little exaggeration that these faults rank with the largest known steeply dipping dislocations of the earth's crust.In the winter of 1939, a mineralized shear zone named the 'Creek vein' was found on the Giant property. It was noted that the space relationship between this shear zone and a body of quartz-feldspar porphyry is roughly the same as that between the Con C-4 shear zone and a body of acid flows lying north of the Con property. Coupling this relationship with the assumption that the movement along the fault is dominantly horizontal, it was postulated that the Giant shear zone represented the faulted extension of the Con C-4 shear zone.As geological information became more extensive, certain weaknesses in this concept became apparent, and when spectacular orebodies were discovered on the Giant property in 1944 the question of possible faulted extensions became an important consideration. Consequently, in the spring of 1944, an extended investigation was undertaken, the results of which are embodied in this paper."

Jan 1, 1954

By John Tribe

"This paper gives the organizational history of Luscar Ltd. and its various coal producing operations. Each 0/ the operations is then described individually. They include the Bienfait Mine, the Boundary Dam Mine, the Diplomat Mine, the Luscar Mine and the Coal Valley Mine. The company's plans/or expansion are also discussed. IntroductionLuscar Ltd. is an Edmonton-based energy company formed in 1967 through an amalgamation of two pioneer coal companies-Mountain Park Collieries and Luscar Coals Ltd. In 1912, Mountain Park Collieries initiated the development of an underground mine in the Coal Branch area of Alberta. This mine necessitated the establishment of a townsite and the provision of rail access. The second operation, Luscar Coals Ltd., was established in 1921 at Luscar, Alberta. This was also an underground operation and required the development of a rail spur and townsite. The product from both mines was used to fuel railway steam locomotives until the 1950's. The market demand for coal decreased as the use of the diesel locomotive increased, so that these operations were finally closed in 1954. Through the amalgamation of the two companies in 1967, however, Luscar Ltd. was formed to become an active participant in the revival of coal operations. Western Canadian Luscar Ltd. is involved in the exploration, development, production and marketing of coal, coal products, oil and gas. Luscar Ltd. is currently participating in five producing mines (Fig. I). The Diplomat Mine, approximately 125 miles southeast of Edmonton, was in production when it was acquired in 1949 by Luscar Coals Ltd. In 1966, the Bienfait Mine and char plant were added. The Luscar Mine, which is a 50/50 joint venture of Luscar Ltd. and the Consolidation Coal Company of Canada, and is operated by Cardinal River Coals Limited, started production in 1969 on the original Luscar Coals Ltd. mine site. The Boundary Dam Mine was opened in 1974. Both the Bienfait and Boundary Dam operations are located in the lignite coal fields of southeastern Saskatchewan. The most recent addition to the group is the Coal Valley Mine, 40 miles southwest of Edson, Alberta. It commenced commercial production in July, 1978 under the operation of Luscar Stereo (1977) Limited."

Jan 1, 1980

By R. M. Giegerich

"This paper begins with a brief history of Madawaska Mines, a brief description of the geology, mining methods and equipment, and the historical development of 7/8-in. tapered drilling equipment. It then outlines the performance characteristics and inherent problems of the traditional 12-degree, tapered connection, blade-type insert bits. Service-free (Unipass) button-type insert bits are presented as a possible solution to these problems. The paper concludes with an analysis of button bit performance to date.Brief History of Madawaska MinesMadawaska Mines Limited, near Bancroft, Ontario, is in Faraday Township, Hastings County, approximately 100 miles northeast of Toronto and 100 miles west of Ottawa.The mine re-opened in 1976committed to 1,500 tons per day to provide approximately 600,000 pounds of yellowcake (U3O8) per year to A.G.I.P. (an Italian government agency) under the joint ownership of Federal Resources Corporation, Salt Lake City (51%), and Consolidated Canadian Faraday Limited (49%). At present, the mine is producing approximately 2 pounds per ton (.1% U3O8) at the rate of 60,000 pounds per month. The mine employs about 400 employees.Brief Description of Geology, Mining Methods and EquipmentGeologyThe Grenville metasediments of the mine area are chiefly paragneiss, amphobolite and some carbonate (marble) rocks, which were intruded by a basic rock, altered to a metagabbrometadiorite. These formations are generally concordant, striking east to northeast and dipping 45 to 60 degrees to the south. Locally, the metagabbro is often discordant. The above group of rocks (mixed hybrid gneisses) forms the hanging wall of the south-dipping Faraday granite sheet and was intruded by nepheline syenite, syenite and granite. The ore occurs in the granite-syenite-pegmatite dykes that are probably genetically related to the Faraday granite. The ore shoots are erratically distributed within the pegmatite bodies, mainly on the hanging or footwalls but also medially. Their size varies from 50 to 350 feet in length, 5 to 40 feet in width and 50 to 200 feet in height. The ore occurs most frequently in a medium-grained granite or syenite, well hematized with 10 to 30% mafic crystals of pyroxene, amphibole and/or relics of the host rock."

Jan 1, 1982

By H. M. Lima, L. A. Gomiero, C. A. de Morais

ABSTRACT The Caetité-Brazil uranium facility produces approximately 400 tonnes U3O8 per year from an ore averaging 0.29% U3O8. The process steps are ore crushing, heap leaching with sulphuric acid, uranium separation and purification by solvent extraction (SX) with a tertiary amine, followed by stripping with a sodium chloride solution, precipitation as ammonium diuranate (ADU), and product drying. A change in the milling process is being evaluated to increase production and uranium recovery. Heap leaching will be replaced by conventional agitated tank leaching of the –590 µm ground ore slurry in a sulphuric acid medium. Replacement of the stripping reagent is also being considered.

Jan 1, 2012

By George Langford

Introduction The fiftieth anniversary is, for an individual or a society, an appropriate time for a review of the past so that events and experiences may be viewed m perspective, and thereby serve as a useful guide to the future. In this review of mining geology it is proposed to set forth the situation as it was when the Institute was founded, and then trace the developments during three appropriate periods-the first from 1898 to 1918 the second from 1919 to 1939 and the third from 1939 to 1948. Mining activities were widespread in Canada in 1898 and some of the operations were considered large for their day. The total value of the metals produced in that year was $21,705,854, and in the case of five metals the output had a value in excess of one million dollars. In order of importance these were gold, silver, copper, nickel, and lead. The important producing areas were ova Scotia, Quebec, Ontario British Columbia, and Yukon. This diversification of the mining areas and the metals produced created an interest in mining throughout Canada, and was an important factor in making Canadians conscious of their mining industry. In the year 1898 geology was a recognized science. The principles of physical geology were well known, but the same cannot be said of economic geology and structural geology. Ore deposits and their occurrence had been studied chiefly in Europe. A great many important observations had been made but the theories linking these facts together were still m a formative stage. The same condition was true of structural geology. These two branches of geological science which are so important in what is now called 'mining geology', had not progressed far enough to be of practical assistance mining operations. For this reason, geologists were regarded as dreamers in ivory towers-a concept chat still lingers in the minds of those who have not kept abreast of the growth of the science.

Jan 1, 1948

By Gonzalo Díaz, Diego Mesa, Willy Kracht

"It is well known that frothers affect the amount of water that is transferred to the froth, which has an effect on both the froth stability and the water recovery. On the other hand, since non-selective recovery by entrainment is directly related to water recovery, it can be said that frothers have an indirect effect on flotation selectivity. Recent research on this subject has shown that the non-selective recovery by entrainment, which is characterized by the entrainment factor, is frother dependent. In other words, the entrainment factor is not unique, but depends on frother type.Having different entrainment factors implies that for the same water recovery, the amount of undesired particles reporting to the concentrate may vary if one changes the frother type, which suggests, as a possible explanation, that it is not only the amount of water in the froth what is affected by frother type, but also the froth structure.The purpose of the current work is to study the effect of frother type on foam structure (two phase froth). A quasi-2D cell operated with a slot sparger was used to study the foam structure in the presence of three different frothers: Methyl Isobutyl Carbinol (MIBC), OrePrep®549, and Octanol at the same gas flow rate and reagent dosage. The foam structure was studied using image analysis, and an algorithm based on textural analysis was developed to classify the foams. The results show that it is possible to classify foams according to the frother used, which proves that frothers have an effect on the foam structure.INTRODUCTIONFrothers are usually dosed paying attention to froth stability, condition that is commonly estimated by sight, according to the operator's criteria and experience. This happens because there is not an established procedure or technique for frother characterization, generating qualitative descriptions such as “powerful” or “selective” frothers, which lack of scientific thoroughness and remain under subjective factors. Nevertheless, several works have been done in this line of research. Moyo et al. (2007) classified frothers based on their water-carrying capacity, proving that this characteristic is related with gas holdup and frother type. Previously, Trahar (1981) had related water recovery and gangue particles recovery, defining the entrainment value (ENT). Nowadays it is known that entrainment affects both hydrophilic and hydrophobic because it is not a selective process. In the last decade some studies (for example the one of Konopacka and Drzymala (2010)) delved into different entrainment behaviours dependent mainly on the flotation type (batch or continuous, agitated or columnar, etc.), but there were no studies on the effect of frother type regarding entrainment, since Rahal et al. (2001) argued that the ENT factor was independent of the frother type and concentration, and froth height."

Jan 1, 2016

"INTRODUCTION Secondary mine ventilation has been hamstrung by the availability of fans that satisfy many competing operational factors. The sometimes legislated requirement of adequate volume to the working face, the minimisation of excavation required to fit the selected secondary fan and the power requirements of various operational phases has, in the past, not been satisfied with just one system. The new system being introduced overcomes all these competing requirements in one simple unit with an added bonus of being very durable without loss of performance when wear occurs on the impeller. Existing Operational Situation Several studies (e.g., CIPEC, 2005; LCG Energy Management Group, 2009) have found that between 42% and 49% of mining energy costs are associated with mine ventilation, depending on the type of mine and the equipment used. If we then look at the general breakdown of installed power of the secondary fan to primary vent fans, the ratio is around 2:1. Thus the total energy costs of the secondary ventilation represents about 25% of the overall mining energy costs. It is of interest to note that the cost of running a typical two stage axial vs the cost of purchasing and general maintenance cost of the same fan over a 10 year period, the breakdown will be conservatively in the order of 40:1.The currently available secondary ventilation axial fan have one duty curve at any given time. Generally this can be changed manually within the motor power parameters but requires a minor outage and removal of the fan to do the pitch adjustments. As the bag vent ducts grow longer, the supplied air reduces to a point where inadequate air is supplied to the working face. This is exacerbated by underground equipment putting additional resistance in the heading and further reducing the supplied air at the working face. This shortfall is normally corrected by the installation of an additional fan in the system to overcome losses in the bag system but comes at a cost of production as the heading needs to be shutdown to install the second fan. This also means that the heading is supplied with excessive air on the shorter runs with a wastage of fan power."

Jan 1, 2019

By J. M. D. Wilson, W. Petruk, C. Coté

"The behaviour of minerals in the Mount Wright spiral circuit was investigated to find methods of improving iron oxide mineral liberation and recovery. The feeds, concentrates and tailings from rougher, cleaner and recleaner spirals in one mill line were sampled before and after the sizing screen openings were reduced from 2 mm to 1.6 mm. Sized fractions of each sample were analyzed with the MP-SEM-IPS image analysis system at CANMET to determine mineral quantities and liberation characteristics of the iron oxide minerals. Mass balance techniques were used to calculate stream recoveries of iron, silica, total iron oxide minerals, hema¬tite, goethite, quartz, ferromagnesian silicates, and liberated and locked total iron oxide minerals for each sieve fraction.The reduction of the sizing screen openings increased the ap¬parent liberation of the total iron oxide minerals in the screen undersize from 89% to 94% and raised the over-all iron recovery from 84.4% to 85.3%. Apparent liberation of iron oxide minerals in the cleaner sand also increased from 70% to 85%, but the – 75 µm fraction re¬mained the only fraction containing an acceptable amount of liber¬ated iron oxide minerals in each case. Due to limitations of spiral and grinding efficiency it is recommended that the cleaner sand be screened at 300 m, the +300 m fraction be reground, and the – 300 p.m fraction be rerouted to the rougher spirals.The amount of fine liberated iron oxide minerals (– 106 m) lost in the tailings was 46 TPH in mill line 3. This value represents 41 wt % of the free fine iron oxide minerals, or 7 wt % of the total iron oxide minerals in the spiral feed. Further work is needed to investigate the possibility of recovering this material by other methods.Middling iron particles (010 50%) and presumably free gangue in the size range –300+ 75 m tend to be recovered by spirals by entrapment."

Jan 1, 1990

By Henry C. Knight

A number of improvements in the techniques of budgetary control have been developed in the 1970's. The most significant of these is zero-base budgeting. This procedure is a marked improvement, because it overcomes some of the key weaknesses inherent in most traditional approaches to budgeting. It incorporates techniques and disciplines which improve the quality of both the budgeting effort itself and the documents that most senior managers will need to evaluate. The end result is a budget that establishes and improves cost effectiveness. This budget is based on resource allocations using cost-benefit criteria and on a system of prioritization for making funding choices. Zero-base budgeting is applied only to costs and expenses that are not conducive to control using industrial engineered standards. Therefore, the benefits attributed to zero-base budgeting will only hold true for administrative, selling, exploration, safety, fire protection and overhead, and other indirect types of costs and expenses. It is in this context that the question of its attractiveness for the mining industry is dealt with.

Jan 1, 1978

A direct comparison has been undertaken between laboratory wind tunnel experimentation and computational fluid dynamics simulation of a 3D manufactured analogue for a body of fractured broken rock, created with CAD/CAM techniques. Detailed descriptions of the ?design? of the analogue (using a discrete element analysis multi-body simulator), its manufacture (using computer aided design and 3D printing technology) and the laboratory experimentation (inserting the physical analogue into a laboratory scale wind tunnel) are presented. The agreement of the results of direct experimental observations on the manufactured analogue with the values from CFD simulations of those experiments justifies the utilization of a CFD environment for the practical investigation of geometric factors controlling air flow and heat exchange in complex assemblages of broken rock blocks. The ultimate goal is described, that of developing functional relations between bulk properties of such assemblages (such as their porosity and bulk density) and the low-level geometric factors that dictate the air flow behaviour, such as the equivalent perimeter length of the cross-sectional area available for flow, or average flow path tortuosity. A practical application area of the work in the mining context is also described; equivalent continuum air flow and heat transfer constitutive models developed on the CFD tool from such functional relations are useful in characterization of seasonal heat storage in large scale bodies (approximately 1 km3) of broken rock.

Aug 1, 2013

By S. Malopheyev, I. Vysotskiy, R. Kaibyshev, S. Mironov

"In this work, the effect of pre-strain rolling on the annealing behavior of friction-stir welded 6061-T6 aluminum alloy was studied. To this end, the as-welded material was rolled to 10 or 20 pct. of thickness reduction prior to the standard post-weld T6 heat treatment. Three rolling directions were the 3-mm thick sheet were considered: along the welding direction, perpendicular to the welding direction, and at the angle of 45° to the welding direction. At relatively low pre-strains (10 pct.), the annealing behavior was found to be very sensitive to the rolling path, and rolling along the welding direction was most effective in suppressing abnormal grain growth. On the other hand, increasing the pre-strains to 20 pct. of thickness reduction inhibited abnormal grain growth irrespective of the rolling path.INTRODUCTION Heat-treatable wrought Al-Mg-Si alloys are widely used due to attractive combination of strength, ductility, excellent corrosion resistance and low cost (Polmear, 2006). To provide the optimal balance of mechanical properties, these materials are typically commercially available in appropriately work- and precipitation-hardened conditions (Polmear, 2006). During conventional fusion welding, however, the prior strengthening effect is totally lost due to elimination of the work hardened structure and dissolution of the strengthening precipitations. An innovative friction-stir welding (FSW) technology may partially overcome this problem. Due to the solid-state character of this process, which involves very large strains, the welded material is characterized by fine-grained microstructure with moderate-to-high dislocation density, and thus the prior work hardening effect may be preserved or even enhanced (Threadgill et al., 2009; Mishra & Ma, 2005). However, heat input associated with FSW inevitably leads to dissolution and/or coarsening of strengthening precipitates, thus giving rise to the undesirable material softening. In an attempt to restore the strength of the friction-stir welded material, the standard T6 post-weld heat treatment has been applied, but this approach was found to lead to abnormal grain growth (Malopheyev et al., 2016; Mironov, 2013, Mironov et al., 2015)."

Jan 1, 2018

By M. L. Haider

Introduction I Appreciate very much the opportunity of discussing with you tonight oil developments in western Canada. These developments are of importance to all of us, first because of their great economic significance to all of Canada, and second because of the location of the new oilfields. Situated as they are in the west and northwest, they are of considerable strategic value from the standpoint of continental defence. The story of oil development in Canada covers a span of almost a century, during which time success in finding reserves of petroleum was barely sufficient to maintain interest in continuing the search. Finally, in 1947, a well of the first importance was completed in Alberta and, judging by discoveries made since then, it appears that Canada, at long last, is to become an important producer of petroleum.

Jan 1, 1950

By Jean Dugas, Roger Sirois

The Mineral Deposits Service of the Quebec Department of Natural Resources is engaged in the preparation of metallogenic maps as a contribution to the Canadian Sub-Committee of the Metallogenic Map of North America. The preliminary work is being done on large-scale maps. The main objective is to clearly represent information on ore deposits in a suggestive way. The design of the legend to meet these requirements is discussed. As these maps are still only descriptive, a further step will be the interpretation of data into metallogenic maps with Jess emphasis on the individual deposits and more on the metallogenic factors. Both types of map should prove useful in the search for ore deposits; the first by providing at once a large amount of information, the second by suggesting the ore controls.

Jan 1, 1967

Mercapto organic compound SDMP was used as a depressant for separation of copper activated marmatite from pyrrhotite in the presence of butyl xanthate. Flotation results show that SDMP has strong depressing effect on pyrrhotite recovery in the absence and presence of copper ion, but has promotional effect on marmatite recovery when added together with copper ion. The flotation test of mineral mixtures shows that copper-activated marmatite could be separated efficiently from pyrrhotite using SDMP as depressant. Infrared adsorption spectra demonstrate that SDMP has a strong adsorption on pyrrhotite surface through its functional groups such as ?SH, -S03.

Jan 1, 2006

By Tatsuya Oki

Tantalum capacitors can be found mounted on printed circuit boards of domestic appliances such as personal computers. These capacitors contain a considerable quantity of expensive metal tantalum and can be detached and liberated from printed circuit boards by impact breakers. In this study, the size and density distribution of the liberated electronic devices were investigated. Then, tantalum capacitors were recovered from other electronic devices using size separation and pneumatic gravity concentration methods. More than 70% of Newton's separation efficiency was obtained for tantalum capacitors. High Newton's separation efficiency could be also obtained for other types of electronic devices such as chip resistors.

Jan 1, 2011

By Walter Curlook

"With Inco recording record profits over the past year, most people have forgotten the painful years of the last recession/depression when Inco was losing up to a million dollars a day for a short period . While high nickel prices have contributed to the exceptional recent profits, the real achievements stem from the tremendous advances in productivity and cost improvements that make Inco one of the lowest cost nickel producers.Some of the major advances in productivity have occurred in the mines. The establishment of Mining Research Departments in both Thompson and Copper Cliff in 1979/80 provided the stimulus and the opportunity to dedicate personnel to specific research projects, on a full-time basis; and more particularly to concentrate on the efficiency of the total mine system. The Copper Cliff North Mine was brought back into production as a research mine dedicated to the development and testing of new mining methods and equipment. A shop facility known as the ""Murray Shop"" was set up as the centre of innovation for the development and construction of prototype equipment required for new bulk mining methods. While other expenditures were being curtailed , investment in mining research was being increased. An early success was an ""in the hole"" drill that could be broken down into small components to access even the remotest sectors of a mine to convert labour intensive undercut-and-fill mining to "" vertical crater retreat "" , VCR, bulk mining. A new mine manufacturing company-Continuous Mining Systems-was incorporated with the objective of building innovative mining equipment, with strong focus on automated continuous sytems. Continuous Mining Systems has now grown to a $25 million per year business. With these synergistic thrusts, the VCR bulk mining method was implemented in all of the Ontario Division mines, raising the percentage of ore mined by bulk mining techniques from 320/0 in 1981 to over 90% today. Coupled with re-designed job responsibilities, sup- ported by appropriate training, mine productivity more than doubled. It was discovered that VCR mining could be adapted to the narrower Thompson mine ores with identical improvements in productivity. Development of the Thompson Open Pit North had an additional favourable impact on production cost s in Thompson. The timing of the open pit development could not have been better. It permitted Inco to rapidly increase production at high productivity and low cost, in years of record demand and prices."

Jan 1, 1990

By W. R. Horn

"WHAT I PROPOSE TO DO is to review or report very briefly and generally on the most important subject areas of environmental concern within the mining industry and to indicate the progress being made. First, however, it seems to me both appropriate and necessary to refer to what I said in an address to the CIM Annual Western Meeting, in November 1971, in Vancouver. At that time, I tried to convey: that the awareness and alertness of this far-flung and diversified industry was sharply on the up-swing; that the knowledge of helpful technology for the abatement of pollution by water and solids was significantly increasing; that most mines were doing something about it; that many had already achieved a recycling of process water to a really significant extent; that progress was being made - though not without considerable difficulty - on the large-scale neutralization and subsequent chemical treatment of acid- and metals-bearing waters; that increasing work was being done by individual mining companies on methods for the vegetation of completed tailings impoundments; and that it had been possible to develop a meaningful estimate of the amount of money to be spent by the industry on environmental control measures during the period 1971-75 (as much as $500,- 000,000 ) . Reference was also made at that time to the constructive work in hand toward the fixation, elimination or dispersion of sulphur from smelters and to the considerable attention which was being given by the indust(y itself toward in-plant problems, e.g., dust and noise. Finally, note was taken of the fact that the inclusion of environmental control costs in the pre-operational financial provisions of new mining operations is now established practice."

Jan 1, 1973

By W. A. MacWilliams, R. G. Reynolds

"This paper describes, for the first time, a patented method of extracting sodium sulphate from a natural deposit in Western Canada. The method resembles, but is not, strictly speaking, solution mining. The fact that a plant based on this method has been in successful operation since late 1969 will be of added interest. The deposit in question is located near Metiskow, Alberta, and conventional surface recovery methods could not be applied because of heavy concentrations of mud. Considerable pilot work went into the separation and recovery process on which the plant operation is based. The history of the industry is covered briefly as background to this development. Today it is clear that the method has broader application within the industry and, in concept, may generate interest in many other applications."

Jan 1, 1973

By T. Verdel, Y. Gunzburger

Rockfalls are major and essentially unpredictable sources of danger, particularly along transportation routes (roads and railways). Thus, the assessment of their probability of occurrence is a major challenge for risk management. From a qualitative perspective, it is known that rockfalls occur mainly during periods of rain, snowmelt, or freeze-thaw. Nevertheless, from a quantitative perspective, these generally assumed correlations between rockfalls and their possible meteorological triggering events are often difficult to identify because i) rockfalls are too rare for the use of classical statistical analysis techniques and ii) all intensities of triggering factors do not have the same probability. In this study, we propose a new approach to investigate the correlation of rockfalls with rain, freezing periods, and strong temperature variations. This approach is tested on three French rockfall databases, the first of which exhibits an outstandingly high frequency of rockfalls (approximately 950 events over 11 years), whereas the other two databases are more typical (approximately 140 events over 11 years). These databases come from (1) the national highway RN1 on La Réunion Island, (2) a railway in the Bourgogne-Franche Comté region, and (3) a railway in the Auvergne region. Whereas a basic correlation analysis is only able to highlight an already obvious correlation in the case of the “rich” database, the newly suggested method appears to detect correlations even in the “poor” ones. Indeed, the use of this method confirms the positive correlation between rainfalls and rockfalls on La Réunion Island database. This method highlights a correlation between cumulative rainfalls and rockfalls in the Bourgogne region, and it detects a correlation between the daily minimum temperature and rockfalls in the Auvergne region. This new approach is easy to use and also serves to determine the conditional probability of rockfall function of a given meteorological factor. This approach will help to optimize risk management in the studied areas based on their meteorological conditions. Nevertheless, even if some rockfalls are correlated to meteorological factors, other seems to occur independently of these factors, which highlights the unpredictability of rockfall hazard.

Jan 1, 2015

By K. Yoshida

Recently, light magnesium alloy with superior heat radiating ability has been attracting attention in various fields. However cold plastic working of the alloy is very difficult and hot working necessary. Furthermore, the magnesium of products with complicated shapes is difficult, the processing cost is high, and the applicability of the alloy is limited. In this study, a technique for obtaining fine wires and tubes by cold drawing is examined to obtain wires and tubes with high strength, quality and surface morphology, while decreasing production cost. In addition, the shearing strain of magnesium alloy wires and tubes drawn under various drawing conditions was calculated by FEM analysis. It was clarified that cold drawing of magnesium alloy is possible. It was also demonstrated that greater reduction of the cross-sectional area could be realized during cold wire and tube drawing by optimizing the drawing conditions.

Jan 1, 2006