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By Y. Zhoa

The surface morphology of materials is of fundamental importance to many surface related applications, such as wetting, friction, reflection, drag, and adhesion. Various approaches for micro/nano patterning atop polymer surfaces have been proposed in recent years. However, a cost effective technique is still highly in demand. In this paper, we demonstrate a novel but rather simple and generic approach for surface micro/nano patterning using shape memory polymers (SMPs). Different types of novel patterns are realized and their 3-D surface features are quantitatively analyzed by a PLµ Confocal imaging profiler.

Jan 1, 2010

By J. Drelich, C. L. White, Ch. Zhou, W. M. Cross, E. T. Zellers, E. M. Nadorny

A laser-based particle deposition (LBPD) technique has recently been developed at Michigan Technological University for patterning mesostructures made of nanoparticles and their clusters. The LBPD technique makes use of laser induced optical forces to transport and pattern nanoparticles on a variety of conductive and non-conductive substrates from nanoparticle-in-liquid suspension. A weakly focused laser beam is used to confine and propel particles along the laser beam. Confinement is accomplished by forces due to optical field gradients that act on polarizable particles and tend to move them to axis of the laser beam. The force propelling the particles along the direction of the laser beam arise from momentum conservation of photons scattered from the particles. In this paper, this novel LBPD technology is briefly reviewed, and several examples of patterning are presented. The size and morphology of mesostrips produced from gold and polystyrene nanoparticles, under a range of deposition conditions, have been characterized by optical microscopy, atomic force microscopy, and scanning electron microscopy. The results presented here demonstrate that gold and polystyrene nanoparticles deposited by LBPD can form clusters of particles. When deposited at an appropriate rate, such clusters can form multilayer mesostrips of high particle density. One goal of research on such systems is to fabricate arrays of parallel lines made up of colloidal particles having a range of surface functionalities. Such arrays have potential for application as novel microsensors for environmental sensors.

Jan 1, 2003

By J. M. Mutmansky

This paper outlines patterns of methane emission in both longwall and room-and-pillar operations and the effects that these patterns have on the decision as to whether the methane is most economically handled by ventilation alone or by means of a methane drainage system in addition to ventilation. The costs of handling the methane in the ventilation system and the costs of implementing the methane drainage system will be discussed as well as the costs related to the production of coal. The important issue of production slowdowns and gas outs will also be discussed as well as the proper response of mine management to such a situation. Suggestions concerning the keeping of production records related to methane problems will be made as well as justification for more intensive economic analysis of coalbed methane extraction and utilization.

Jan 1, 1998

By T Christie, A Swain

Patterns of quartz veining in epithermal gold-silver deposits at Wharekirauponga, Neavesville and Ohui in the Hauraki Goldfield, have been analysed to determine the effects of different lithologies on vein distributions. At Wharekirauponga, quartz veins are hosted in rhyolite and minor andesite, with the andesite containing slightly higher gold grades. Local basement andesite, rhyolitic tuff and silicified black shale host gold-bearing quartz veins at Neavesville. At Ohui, quartz veins are hosted in rhyolite, rhyolitic tuff and andesite. Fractal analysis was used to quantitatively describe the distribution of veining. The fractal dimension (D) of veining in silicified tuff is 0.25, moderately silicified rhyolite has D = 0.23 - 0.26, clay-altered andesite has D = 0.3, strongly silicified rhyolite has D = 0.3 - 0.39, silicified andesite has D = 0.4, and silicified black shale has D = 0.43. The D values are related to the composition of the host rock, and appear to be controlled by its competency. Hydrothermal silicification results in increased competency and higher D values. Vein thickness frequency plots for different lithologies show that andesite at Ohui, and to a much lesser degree at Wharekirauponga, contains more thick veins than rhyolite and tuff. Gold grades show a strong to fair correlation with higher vein density in three drillholes at Wharekirauponga. The fractal dimension of veining is an important control on fluid flow and gold deposition within an active epithermal system. Vein systems with higher D have a greater density of veining which would have favoured increased fluid-rock interaction. Lower D vein systems have more clustered arrays. The increased fluid-rock interaction induced by a high D vein system, when combined with a reactive host rock, results in an environment which is highly favourable for gold deposition. This situation is seen in the andesite at Wharekirauponga.

Jan 1, 1994

Andy H. Vassiliou – Introduction Ladies and gentlemen,.good evening and welcome to the Paul F. Kerr Memorial Symposium dinner. I believe we are all here to honor the memory of a great teacher and advisor, and a true friend -- Professor Kerr, or Dr. Kerr, or to most of us who were his students, "Pappy" Kerr. Most of us who attended the Paul F. Kerr Memorial Symposium earlier today at the New York Hilton had the opportunity to read, or listen to, or discuss scientific papers presented in honor of Dr. Kerr. In addition, all of the speakers had the opportunity to reminisce about their association with Dr. Kerr, who was credited as having contributed substantially to their graduate education and the development of their careers. Dr. Kerr's two daughters -- Ruth and Nancy -- who attended the Symposium at the Hilton are also here with us tonight. I think we should keep tonight's festivities on an informal basis since we are all old friends or former students of Dr. Kerr. Some of us may want to say a few words about our experiences at the time we were students at Columbia, and hopefully include some anecdotes relating to Professor Kerr. I would like to invite everyone to do so, but first we have arranged for two of us to be the lead speakers, whom I will introduce in a few moments.

Jan 1, 1985

By Jan Krull

A high productive coke making process in connection with stringent emission control has clearly become a demand of plant operators and stakeholders. Further to this, availability, quality and coal costs are key concerns for the iron and steel industry in its efforts to optimize raw material cost. Today, the optimization of raw material cost in integrated steel works has further gained priority. Coking coal reflects up to 20% of the cost of steel. In top charged batteries coal preparation and blending is one of the concerns to lower coal cost by maximizing the percentage of non-coking coals in the blend. Stamp charging technology is technologically and economically an effective solution in the process of pre-carbonisation. Paul Wurth’s jumbo top charged oven as well as proven stamp charging technology have recently set new benchmarks in Europe, India and Brazil in terms of productivity, stability and emission control.

Aug 1, 2018

By Pedro H. Tumialán de la Cruz

La Cordillera Negra está constituída por rocas volcánicas que han sido intruídas por stocks porfiríticos de composición intermedia en el Terciario Superior con mayor afloramiento en las partes altas. De acuerdo a la metalogenética, las vetas polimetálicas se encuentran las partes altas cercanas a los stocks de los intrusivos y en los mismos stocks de dicha cordillera, En este sentido, algunos yacimientos polimetálicos contienen plata en zonas de mayor temperatura respecto al plomo y zinc, mientras que los yacimientos tipo estratos se encuentra ligado son singenéticos y se observan en las rocas estratificadas del Cretáceo. Por ello, el presente texto señala que la Cordillera Negra ofrece las condiciones idóneas metalogenéticas de yacimientos tipo filoniano hidrotermal en el departamento de Ancash.

Nov 8, 1984

By C T. Senra, A Souza

Increasing fuel prices, unavailabilty and high prices of tyres have imposed tremendous challenges for large open pit operations. Carajßs open pit mines, one of the largest iron ore projects in the world, has been particularly affected due to the high amount of giant trucks operating in this site. On the other hand, environmental constraints push the mining industry towards reductions in fossil fuels, noise and waste generation. As a feasible response to these requirements, an alternative mining method for open pit mining, aiming to reduce or even eliminate the need for trucks has been developed, based primarily on coal opencast continuous operations. This innovative approach for open pits involves the replacement of trucks by fully-mobile crushers, bench conveyors and ramp conveyors. Two different applications have been developed for exploiting waste and ore at Carajßs largest pit, named N4E. To make it possible, mine planning paradigms should be replaced leading to new conceptual design of open pits. This paper shows two case studies (waste and ore conceptual design) carried out at Carajßs mines to anticipate and put forward the future of open pit mining, proving that our industry would be greatly affected by this new way of exploitation, reducing thousands of tons of fossil fuels. Productivities can be enhanced and environmental performance greatly improved. In this approach mine automation can be easily implemented reducing operating costs and man's fatigue.

Jan 1, 2009

This paper describes the back analysis of the Pavoncelli tunnel, an hydraulic tunnel which was excavated between 1904 and 1915 in South of Italy and experienced severe damages during the 1980 Irpino-Lucano earthquake. A numerical simulation which is intended to study the behaviour of the tunnel during this seismic event is presented, also accounting for the swelling phenomenon that took place during and after construction.

May 1, 2009

By M. Olper

The change in regulations and the strong attention to the environment have suggested some changes in the traditional processes for the recycling of lead acid batteries. Engitec Technologies, marketing the Integrated CX® System, is continuously updating and improving its technology to fulfil the technical, economical and ecological requirements coming from the market and from the environmental authorities. In this paper Engitec Technologies will present the latest technical innovations introduced in the Integrated CX® System.

Jan 1, 2008

This paper presents an overview of a program PC-BC developed for application to the design and evaluation of block cave operations. Conventional mine planning software tools are not well suited to the evaluation of this type of deposit. The paper looks at the modelling approach as applied to a block cave mining project. The following steps are described:Initial preparation of data including block models, draw point footprint geometry and draw cone geometry. Computation of individual draw point reserves. Procedure for modelling of vertical mixing of material within each draw point and subsequent determination of the best height of draw for each draw point based upon an economic cut-off value. Smoothing of draw heights amongst neighbouring draw points to produce a realistic draw envelope. Mineable reserves within the envelope are then computed. Tools for preparation and evaluation of various production schedules. This includes definition of draw rates, and rates for commissioning new draw points. In an operating mine, the capture and analysis of daily draw tonnages is important. How PC-BC accommodates this is described as well as the processes for depleting the draw column reserves. In the 12 years since the program was first developed, it has been used on a number of projects for feasibility studies and operating mines. Some practical examples of the use of the program in these projects are presented. Finally, some commentary on the sensitivity of various parameters is presented. Particular emphasis is placed on the overall footprint design.

Jan 1, 2000

By Altair Lúcio de Souza

Foi implantado um software, PCT (Production Control Tool), de integração e coordenação do fluxo de dados entre os seguintes níveis de automação: nível 3, onde se encontram os dados de especificação do produto e sequenciamento de produção, e nível 2, onde se encontram os modelos matemáticos, resultados do processo, interface com medidores e rastreamento da produção. No processo de construção do PCT viu-se um grande potencial de desenvolver outras funcionalidades, devido enorme flexibilidade dessa ferramenta, como gerenciamento da produção, auxílio na inspeção de qualidade e controle estatístico do processo. Isto levou a criação de um sistema amigável de fácil utilização, utilizado tanto pelos operadores da Linha e inspetores de qualidade como também pelos analistas do processo, auxiliando na otimização da Linha de Tiras a Quente da Gerdau.

Aug 17, 2017

By Steve Kral

The Prospectors and Developers Association of Canada (PDAC) was established in 1932 in response to proposed regulations that would have threatened prospectors in Ontario. From there, the association grew to represent the interests of Canada?s mineral exploration and development industry. The PDAC?s mission statement reads: ?The PDAC exists to protect and promote the interests of the Canadian mineral exploration sector and to ensure a robust mining industry in Canada. The PDAC will encourage the highest standards of technical, environment, safety and social practices in Canada and internationally. ?Today, the PDAC?s 6,000 individual members include prospectors, developers, geoscientists, consultants, mining executives and students. In addition, the association?s membership includes 950 corporate members, representing senior, mid-sized and junior mining companies in addition to organizations that provide services and equipment to the mining industry. In 2010, the PDAC adopted its e3 Plus principles, a framework to guide its membership in responsible exploration.

Jan 1, 2011

By A. Norori-McCormac

"Air recovery, the fraction of air entering a flotation cell that overflows the cell lip, is linked to flotation performance, and it has been shown through industrial testwork that operating flotation cells at air rates that yield the Peak Air Recovery (PAR) results in high mineral recovery. For operating parameters over which flotation plants have little control, such as particle size, investigating the effect on the position of PAR, and the subsequent effect on flotation performance, proves more challenging. To this end, we have developed a bench scale flotation system that runs continuously and exhibits froth behavior similar to that found industrially, allowing the study of such parameters as particle size in addition to air rate. The bench scale system comprises a 4 l baffled cylindrical flotation cell, stirred by a Rushton impeller. The concentrate is recycled back into the pulp, allowing for continuous operation. Glass beads are used as solid particles, allowing a wide range of particle sizes to be tested, with TTAB as collector and MIBC as frother. The system allows operation at air rates typical of industrial flotation systems (1 -2 cms-1 superficial gas velocity), in addition to yielding a froth that coalesces and bursts and exhibits a peak in air recovery as cell air rate in increased. Solids and water recovery is also measured. The results show that air recovery is sensitive to changes in particle size. The intermediate size distribution showed a peak in air recovery (PAR) that corresponded with the maximum solids flowrate, as found industrially. It is shown that finer particles do result in more stable froths and higher recoveries, particularly at low air rates. The effect of particle size on the position of PAR is not yet unequivocally determined from these results."

Jan 1, 2014

By Paul J. Axtell

Self-hardening cement-bentontie (c-b) slurry walls were constructed as shear walls to stabilize the downstream slope of Tuttle Creek Dam near Manhattan, Kansas. The slope stabilization was required to protect the existing pressure relief well system located at the downstream toe of the dam. The wells require protection from slope deformation induced by liquefaction of the foundation sands during or immediately after the design seismic event. The shear walls are transverse to the axis of the dam, unreinforced, and relatively brittle members that may be exposed to relatively large shear strains, and possible cracking, during or immediately after shaking. An extensive laboratory investigation was conducted on recovered core samples to optimize the mix design and stabilization scheme. Furthermore, as is the topic of this paper, a portion of the laboratory investigation was to determine the large-strain, or post-peak, shear strength of the c-b material for use in limit-equilibrium slope stability analyses and numerical deformation modeling to assess the magnitude of permanent deformation caused by the design earthquake. These data may be beneficial to other projects that are considering the use of unreinforced c-b slurry walls for seismic retrofit purposes.

Jan 1, 2010

By Seymour C. A

Peak Downs Mine, a five million tonnes a year coking coal operation, strip mines a, series of Permian coal seams. Seam thickness ranges from 0.5m to 5.0m, and seams consist of multiple coal plies with intermediate shale and mudstone partings. Four 47m3 draglines strip overburden to a cover depth of up to 60m. Coal loading is by 12m3 shovels and 14m3 to 18m3 front-end loaders. Parting removal takes place where the layer of shale and mudstone between seams exceeds 0.3m in thickness. Parting has been removed by a wide variety of earthmoving equipment in order to evaluate the problem and to select the optimum method from an operational and economic standpoint. Multi-seam stripping of the thicker seams is accomplished by working draglines from spoil- pile benches. Coal seams thinner than lm are recovered by dragline and stacked in the pit for later loading.

Jan 1, 1974

By Baird G. R, Jurak R. N

In this study Dynamic Finite Element Modelling is used to investigate the distribution of peak particle accelerations (PPA) induced in a rock mass by a vertical decked column of explosives. The rock mass is assumed to be viscoelastic. The influence of the delay time between decking charges, the viscosity attenuation (quality factor Q), the decking configuration, and the velocity of detonation (VOD) on PPAs is examined. The results of this paper are relevant to fragmentation since the nature of the fragmentation is related to the stress magnitude and hence the PPAs. It was found that increasing the VOD, and increasing Q increases the PPAs in the neighbourhood of the blasthole. However, the VOD and rock quality factor Q have little influence upon the distribution of PPA. It was also found that an even distribution of PPAs, at a fixed distance from the blasthole, could only be obtained by increasing the ratio of charge length to stemming length. The study showed that the amplitudes and distribution of PPA surrounding the blasthole was approximately independent of the delay time between the decked charges. The modelling also shows that the particle accelerations at locations below the bottom of the charge are relatively small and so the model predicts no substantial damage below the bottom of the charge after blasting.

Jan 1, 1995

By S. R. Dindarloo

Although blasting is one of the most widely used methods for rock fragmentation, it has a major disadvantage in that it causes adjacent ground vibrations. Excessive ground vibrations can cause a wide range of problems, from nearby residents complaining to ecological damage. Prediction of blast-induced ground vibration is essential for evaluating and controlling the many adverse consequences of surface blasting. Since there are several effective variables with highly nonlinear interactions, no comprehensive model of blast-induced vibrations is available. In this study, the support vector machine (SMV) algorithm was employed for prediction of the peak particle velocity (PPV) induced by blasting at a surface mine. Twelve input variables in three categories of rock mass, blast pattern, and explosives were used for prediction of the PPV at different distances from the blast face. The results of 100 experiments were used for model-building, and 20 for testing. A high coefficient of determination with low mean absolute percentage error (MAPE) was achieved, which demonstrates the suitability of the algorithm in this case. The very high accuracy of prediction and fast computation are the two major advantages of the method. Although the case study was for a large surface mining operation, the methodology is applicable to all other surface blasting projects that involve a similar procedure.

Jan 1, 2015

By W. P. Haynes

ESTIMATED United States crude-oil production during 1943 established a new annual peak of 1,500,000,000 barrels, a daily average of 4,118,000 barrels. This would be an increase of 315,000 barrels per day, or 8 per cent over 1942 and 7 per cent over 1941, the previous peak. During the first ten months of the year, production jumped from 3,782,000 barrels per day in January to 4,400,000 in October. Available data for the last two months of the year indicate a leveling off of this trend, with daily rates slightly above 4,400,000 barrels.

Jan 1, 1944

By Pierre Buteau

Peat/ands distribution in Canada is widely spread thoughout the country and corresponds to a wide spectrum of wetland habitats which overlay peat deposits. The development and the evolution ofpeat/ands and peat deposits are closely linked together, since the vegetal remains of the peat deposits originate from the peatland habitats, and the peatland habitats constitute a response to many factors, including the properties of the substrate, which are the peat deposits. Peat/ands are defined as waterlogged terrains where the production of plant materials usually exceeds the rate of decomposition. The underlying peat deposits consists of organic residues associated to peatland vegetation, more or less decomposed, built up and kept under anaerobic conditions. Peat/ands evolution and distribution are determined primarily by climatic factors, but also by the geomorphology and edaphic conditions. All of these create particular hydrodynamical environments which will vary according to different regional settings, and sequentially to an evolutive time frame.

Jan 1, 2001