bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Electronic Nose Systems on Animal-Source Food
Authors: Di Rosa Ambra Rita , Leone Francesco
Published: March 2018

Electronic nose, which is designed to perceive artificially the odour-active molecules in a sample headspace, has seen an increased use in the food industry as a rapid and reliable tool for quality assessment, classification, and authentication of several food items. The use of chemometrics and pattern recognition methods, together with gas sensors, emerged to be a very powerful analytical approach. In this chapter, an overview of the recent achievements in the field of electronic nose applications on animal-source food is given. Moreover, the authors deal with the recent research trends to overcome the actual sensor shortcomings, including sensor fusion techniques and their applications to evaluate animal-source foods and novel electronic nose systems.
Automatic Voltage Regulator System Tuning Using Swarm Intelligence Techniques
Authors: Bahgaat Naglaa K. , Hassan Mohamed Ahmed Moustafa
Published: March 2018

The voltage regulator may be used to regulate one or more AC or DC voltages in power systems. Voltage regulator may be designed as a simple “feed-forward” or may include “negative feedback” control loops. It may use an electronic components or electromechanical mechanism on the design. AVR is keeping constant output voltage of the generator in a specified range. The PID controller can used to provide the control requirements. This chapter discusses some modern techniques to get the best possible tuning controller parameters for automatic voltage regulator techniques such as particle swarm optimization, adaptive weight particle swarm optimization, adaptive acceleration coefficients, adaptive acceleration coefficients. Also, it presents a new adjustment modified adaptive acceleration coefficients and a discussion of the results of the all methods used. Simulation for comparison between the proposed methods and the obtained results are promising.
Artificial Neural Network for PWM Rectifier Direct Power Control and DC Voltage Control
Authors: Fekik Arezki , Denoun Hakim , Azar Ahmad Taher , Zaouia Mustapha , Benyahia Nabil , Hamida Mohamed Lamine , Benamrouche Nacereddine , Vaidyanathan Sundarapandian
Published: March 2018

In this chapter, a new technique has been proposed for reducing the harmonic content of a three-phase PWM rectifier connected to the networks with a unit power factor and also providing decoupled control of the active and reactive instantaneous power. This technique called direct power control (DPC) is based on artificial neural network (ANN) controller, without line voltage sensors. The control technique is based on well-known direct torque control (DTC) ideas for the induction motor, which is applied to eliminate the harmonic of the line current and compensate for the reactive power. The main idea of this control is based on active and reactive power control loops. The DC voltage capacitor is regulated by the ANN controller to keep it constant and also provides a stable active power exchange. The simulation results are very satisfactory in the terms of stability and total harmonic distortion (THD) of the line current and the unit power factor.
Fostering Audience Awareness and Iterative Collaboration for the Creation of Promotional Texts
Authors: Tommaso Laura , Verzella Massimo
Published: March 2018

This chapter presents a comprehensive account of an online collaborative project designed to develop students' rhetorical and linguistic skills in a trans-cultural perspective. This project guided a group of college-level English learners (native speakers of Italian) towards the production of pre-trip promotional materials for the Molise region in central Italy. Thanks to the feedback offered by the American students, the Italian students critically examined the effect of their stylistic choices and the ways in which these choices positioned audiences for particular purposes, revealing and/or shaping attitudes, values and perspectives. The authors believe that the project can be replicated by instructors who are keen to add an intercultural component to their courses.
Co-Writing and Cross-Cultural Networking
Authors: Steinmann Heather , Saduov Ruslan T.
Published: March 2018

This chapter is a teaching case study which draws on Kolb's experiential learning model and Latour's Actor-Network theory, specifically, the ideas of learning as a process rather than as an outcome and of technological space as a cross-cultural network actor. The authors report on a collaboration between undergraduate-level students at a US university and graduate-level students at a Russian university within the Trans-Atlantic and Pacific Project originated to set up international academic collaborations. The chapter provides a theoretically grounded description of the project's successes and failures as well as guidance for teachers wishing to use experiential learning through networking as an instruction tool.
Meta-Knowledge on the TAPP and ORLIMPA Projects
Authors: Minacori Patricia
Published: March 2018

This chapter describes how within the framework of distant collaborative projects between European and American universities, combining the activities of technical communication and translation, Paris Diderot students are required to write a blog, to analyze not only the final product but the process they went through. These blogs constitute a source of meta-knowledge about all of the activities taking place over the course of the project. The Paris Diderot students have the task of translating a text designed by technical communicators. However, the final project, the translation, does not reflect the different facets of the project. Asking students to produce a blog in order to gain feedback about the project is rich in learning because students and professors can concurrently analyze the strategies of collaboration employed, the method of translation, the project management and tools used, as well as the creativity of the students and finally, the lessons drawn from these experiences. It is concluded that these elements constitute meta-knowledge as objects of research.
Collaborative Student Translation Projects
Authors: Ciobanu Dragoș
Published: March 2018

This chapter describes how Project-based learning (PBL) is a training method proven to make learning experiences memorable, motivating and meaningful. This article summarises the responses given between 2015 and 2016 by members of the European Masters in Translation (EMT) Network to a detailed questionnaire on the way in which collaborative translation projects are conducted throughout the network. These responses have also been enriched with the outcomes of follow-up discussions led by the EMT Working Group on Collaborative Learning and e-Learning, as well as 1.5 million words' worth of collaborative localisation projects organised in the University of Leeds Centre for Translation Studies between 2012 and 2017. The result is an inventory of approaches and best-practice tips organised into five major sections covering the main aspects associated with designing, implementing and promoting collaborative student projects in translation and localisation.
Professionalisation in Translator Education Through Virtual Teamwork
Authors: Kerremans Koen , van Egdom Gys-Walt
Published: March 2018

This chapter describes how in recent years, much attention has been devoted to professionalisation in translator education. As a result, many different pedagogical activities have been proposed, focusing on the question of how students can acquire professional skills during their studies. This chapter focuses on one such pedagogical activity, i.e. the organisation of Simulated Translation Bureaus (STBs), in which students work on translation projects obtained from real (or fictitious) clients. The aim of the activity is to imitate as best as possible the tasks that translators face in real translation projects. In this chapter, the authors argue that collaboration between STBs through virtual teamwork can increase the degree of authenticity in simulated translation workflows. In the first part of this chapter, consideration is bestowed upon the underlying reasons for the implementation of STBs in translation curricula. In the second part, possibilities for collaboration in the context of the International Network of Simulated Translation Bureaus (INSTB) are be discussed.
The Benefits of Applying GIS in Spiritual Tourism Management and Promotion
Authors: Haq Farooq , Medhekar Anita
Published: March 2018

The main contribution of this chapter is to critically discuss the benefits of applying geographic information systems (GIS) as a tool for management and promotion of spiritual tourism circuits (STC) and ST destinations. This research-based chapter also examines the extent to which GIS can be used in spiritual tourism management and promotion, proposes a model for the use and benefits of GIS in spiritual tourism management and promotion in India and Pakistan, and proposes GIS connected STC. This chapter identifies the socio-economic and business benefits of applying GIS to spiritual tourism circuits (STC). In this research, the spiritual tourism product is exclusively based on spiritual place, sites, or destinations, which is also called spatial or geographical data.
Socio-Ethical Impact of the Emerging Smart Technologies
Authors: Machidon Octavian M.
Published: March 2018

Today, technology is being integrated in all social environments, at home, school, or work, shaping a new world in which there is a closer interaction between human and machine than ever before. While every new technology brings along the expected “blessings,” there is also the thick end of the stick, namely the potential undesired effects it might cause. Explorative research in smart and enhancing technologies reveals that the current trend is for them to transcend to persuasive technologies, capable of shaping human behavior. In this context, this chapter aims at identifying the social and ethical implications of such technologies, being elaborated after reviewing literature from various research domains. It addresses the implications of today's smart and enhancing technologies on several levels: health repercussions, the social and behavioral changes they generate, and concerns of privacy and security. Also, the chapter emphasizes the need for scientists and researchers to engage not only with the technical considerations, but also with the societal implications mentioned above.
Individual Risk Assessment (ERIN)
Authors: Rodríguez Yordán
Published: March 2018

Work-related musculoskeletal disorders (WMSDs) prevention has become a global phenomenon and nowadays is one of the main challenges that ergonomics and work safety professionals face. The evaluation of risk factors exposition related to the WMSDs is one of the main activities that are performed for prevention. In order to accomplish it, many ergonomic assessment methods have been developed. In this chapter, an ergonomic observational individual risk assessment (ERIN) method is presented, which is distinguished for being easy to learn, apply, and it needs short training time. Results on the reliability, validity, and usability studies of ERIN are included too, as well as an example of how it can be used in the workplace intervention process.
Ergonomic Bench to Decrease Postural Risk Level on the Task of Changing Forklift's Brake Pads
Authors: Realyvásquez Arturo , Hernández-Escobedo Guadalupe , Maldonado Macías Aide Aracely
Published: March 2018

Development of musculoskeletal disorders caused by awkward postures are present in tasks performed in small companies. Consequently, this chapter evaluates the postural risk level associated to the task of changing brake pads of a forklift, and proposes the design and the implementation of an ergonomic bench that helps to reduce this level of postural risk. As methods, postural risk level corresponding to the task was determined using REBA, whereas anthropometric analysis was developed, and axiomatic design and TRIZ methodologies were used to develop the proposed design. Results showed a REBA score of 8 (high-risk level). The final design is done of nylamid, and it contains some TRIZ principle, such as copying, extraction, and dynamicity. Respect axiomatic design, the bench meets some functional requirements, such as support the user's weight, avoid unsafety conditions, and be adjustable. With the TRIZ principles and functional requirements, this bench will help diminish postural risk level.
Usability Test and Cognitive Analyses During the Task of Using Wireless Earphones
Authors: Bustamante Nora G. , Maldonado Macías Aide Aracely , Durán Adrian A. , Ortiz Nicolás Juan Carlos , Quiñones Andres R.
Published: March 2018

The use of novel technologies can be complicated for some people; even products designed for everyday use can present problems. If a product is difficult to use, it causes frustration and prevents usage. The objectives of this study are to conduct a usability test, assess the mental workload, and identify potential human errors during the process of listening to music using wireless earphones from a mobile phone device to detect which operations were the hardest in order to suggest modifications to the design and to bring a better experience to the user. During the usability test some difficulties among users were detected and a hierarchical task analysis (HTA) was developed. NASA-TLX and SHERPA methods were applied. The use of these earphones resulted in an intermediate mental workload, and four types of human errors were identified. The methods used in this study helped to detect those difficult tasks and subtasks for the users.
A Creative Teaching Strategy to Generate Concept Designs and Their Possible Application in Tourism
Authors: Solórzano Juan Manuel Madrid , Anchondo Ercilia Loera , Peinado Coronado Porfirio , Nogueira Ludovico Soto
Published: March 2018

The aim of this chapter is to present the activities and results from a didactic strategy developed to generate concept designs that can be perceived as possible objects to be manufactured. This strategy is directed towards university students on an intermediate level with low performance in the industrial design major. Similarly, this chapter analyzes the importance of creating concept designs for promoting touristic destinations through a logo. The methodology for the present study is of qualitative nature and employs action research. Some methods stemming from a focus on user-centered design and creativity procedures were utilized. The collage technique and a semi-structured interview were the tools utilized on focus groups. It was concluded that the pedagogical proposal contains activities that assist the student in generating ideas in a systemized way. These actions can be applied with different purposes such as creating a design with the aim of promoting a product and a touristic destination.
Durable and Self-Healing Cement Systems: Lab Testing and Field Deployment
Authors: Al-Yami A. S. , Wagle Vikrant , Santagati Antonio A. , Taoutaou S.
Published: March 2018

Pressure and temperature changes during the life of the well could cause some Casing-Casing annulus (CCA) pressure leaks in the annulus between 13 3/8" and 9 5/8" casings, and 13 3/8" and 18 5/8" casings. Such failures in wellbore isolation prevent us from taking full potential of our high performance wells, Al-Yami et al. 2018.

Different solutions have been presented in past to achieve long term well integrity, however this paper works on the postulate that long-term zonal isolation can only be provided by a competent annular seal which can be achieved with improved cement bonding and a cement system which withstand sheath stresses due to well operations. Solution provided in this paper includes process of improved slurry system's design, execution and evaluation for offshore operations.

To overcome these problems, self-healing cement system and durable cement systems were developed to ensure well integrity during the life of the well, providing competent annular pressure seal. Unlike conventional cement systems, self-healing system expands after setting, improving cement bonding and sealing micro annuli that can cause unwanted gas migration. Due to its improved mechanical properties and low Young's modulus it can withstand cement sheath stresses well operations. For formation where hydrocarbons are not present to trigger the self-healing mechanism, the durable cement system is the solution to use. It has suitable components to optimize its mechanical properties to withstand pressure and temperature cycling.

Under most failure conditions, tensile strength of a cement has a greater impact on its failure as compared to the cement's compressive strength. Consequently, increasing tensile strength of a cement is higher priority than increasing its relative compressive strength. This can be achieved by using additives such as latex, polyvinyl alcohol or fibers or simply by increasing cement flexibility Al-Yami et al. 2018. The objective of this paper is to highlight new designs and applications for self-healing cement system and durable cement.
Grain boundaries in metals
Authors: Weinberg F
Published: March 2018

The structure of grain boundaries in metals has been reviewed for an article to be included in Vol. 8 of Progress in Metal Physics.
The crystallography of compounds in the calcium oxide-niobium pentoxide system
Authors: Rowland J F , Bright N F H , Jongejan A
Published: March 2018

In the course of work on the CaO-Nb 2 0 5 -Si0 2 system, a series of compositions on the CaO-Nb 2 0 5 binary join has been studied. There are indications of the existence of three calcium niobates. These compounds have been characterized by X-ray powder
diffraction and optical data. Single crystal studies have given information concerning the crystallography of these materials.
Embrittlement of solid metals in a liquid metal
Authors: Morgan W A
Published: March 2018

This review of the published work on the embrittlement of solid metals by lower melting-point liquid metals is published by permission of the Director, Mines Branch, Department of Mines and Technical Surveys, Ottawa, Ontario, Canada. The author is Head, Ferrous
Metals Section, Physical Metallurgy Division of the Department.
Radiochemical evaluation of fire assay Canada method for determination of silver
Authors: Faye G H , Inman W R
Published: March 2018

Radiochemical experiments using silver-110 have been performed to evaluate the fire assay method for the determination of silver. The losses of silver during crucible fusion, scorification, and cupellation have been measured under a variety of experimental
conditions. The major loss occurs in the cupellation step and it is difficult to reduce this loss to less than 2% of the silver present. In experiments with pure fluxes the loss of silver to the slag during crucible fusion was approximately 0.2%; that to the crucible wall was approximately
0.5%. The loss may exceed 2% in the fusion of charges rich in copper and/or nickel sulfide materials or with charges giving Viscous slags. Loss of silver to the slag during scarification of impure lead buttons was approximately 0.2%
Properties of sand-cast magnesium alloys part iii: effect of titanium additions to magnesium-zinc alloys
Authors: Lagowski B , Meier J W
Published: March 2018

A study was undertaken to determine the effect of titanium additions on the properties of sand-cast magnesium-zinc alloys. Results indicate that some grain refinement was obtained for alloys containing 1-8% Zn which resulted in improved mechanical properties.
The most effective grain refinement was obtained in the range of 6-7% Zn, with properties in the fully heat treated (T6) condition of UTS-39 kpsi, 0.2% YS -24 kpsi and 8% elongation. Although these values are higher than those obtained on the binary Mg-Zn alloys, they are still not
comparable with those obtainable from zirconium containing alloys (ZK61-T6).
Studies of the double layer at the oxide-solution interface
Authors: Ahmed S M , Maksimov D
Published: March 2018

The double layer at the oxide-solution interface has been examined by studying the equilibrium distribution of the potential-determining ions (H+ and OH- ) at the interface as a function of their electrochemical potentials. The oxides investigated were alumina,
cassiterite, hematite, magnetite, rutile, thoria, and zirconia in solutions of KNO3, KC1 and NaC104. Information has been obtained on the zero point of charge, the surface charge densities (qt.), the differential capacities (C±), and the effect of q± on the interfacial tension. The data
are discussed with respect to current theories of the double layer.
Lowdensity catalysts and catalyst supports part i. the preparation of highly porous alumina
Authors: Shaw G T , Parsons B I
Published: March 2018

A technique is described whereby highly porous, low-density alumina can be prepared by dehydrating hydrous aluminum hydroxide gel in thin layers or small-diameter extrusions at low temperatures until at least 25-30 7. of the water present has been removed,
followed by conventional high-temperature drying and calcination. The procedure works well with any aluminum hydroxide gel which has been precipitated with a carbonate. The maximum allowable bulk gel temperature in the low-temperature drying step is 100 °C. The preferred temperature is 75
°C or less. Limited control of the pore size and pore volume (in the range 1000-20 A radius and 0.5 to 2.2 ml/g) can be achieved by regulating the conditions affecting the bulk gel temperature in the low-temperature drying step, e.g. oven temperature, circulation of the air, thickness of gel
layer, etc. The type of drying atmosphere and the age of the hydrous gel are not critical factors. The results of both laboratory-scale and pilot-plant-scale experiments are described
Crystal growth part iv: the arsenides and sulpharsenides, of cobalt, iron, and nickel
Authors: Ripley L G
Published: March 2018

This report deals with an applied research project to explore the preparation and the growing of single crystals of sixteen arsenides and sulpharsenides of cobalt, iron, and nickel. A significant start has been made in the understanding of the growth problems
presented by this group of compounds, but much more research needs to be done. The prime growth procedure was the chemical vapour transport using iodine as the carrier. Good single crystals of safflorite (CoAs 2 ), loellingite (FeAs 2 ), skutterudite (CoAs 3-x ), and cobaltite (CoAsS) were obtained
by this procedure; the first two listed were in the millimetre size range. Three other growth procedures were tried: (1) the modified "melt-and-anneal" method, which was partially successful in the preparation of langisite (Co O 8 Ni 0 As); (2) the vapour transport method; . . 2 and (3) the flux
growth method. The last two methods were not successful in the cases to which they were applied
Kinetics of gold cementation on zinc
Authors: MacKinnon D J , Ingraham T R
Published: March 2018

The rate of gold cementation on zinc was measured by atomic absorption spectrophotometric analysis while rotating zinc cylinders in deoxygenated alkaline cyanide solutions at controlled peripheral velocities and temperatures. The dependence of the rate constant
on peripheral velocity and temperature indicates that the rate is diffusion-controlled. Optimum rates of gold cementation on zinc were obtained from solutions containing 1 x 10-1 M NaOH and 5 x 10-3M excess NaCN. The high initial rate decreased rapidly after the first 30 minutes of reaction time.
The addition of more NaCN at this point caused the reaction to resume its initial rapid rate. The addition of impurities such as Na2 S, Na2S2 03 , NaCNS and Cu caused a decrease in the rate constant for gold cementation on zinc. The addition of Cd, Pb and Ag increased the rate constant, but Se had
no appreciable effect on it.
Exploratory study on galvanizing of iron single crystals
Authors: Ruddle G E , Sebisty J J
Published: March 2018

Single crystals of iron with a range of low-index orientations were galvanized in pure zinc in a specially constructed hydrogen atmosphere apparatus. Significant reaction effects found on (110), (100), and (111) surfaces of commercial single crystals indicated a
positive relationship between galvanizing reactivity and crystallographic orientation of the iron substrate surface. The nucleation and growth mode of the predominant e iron-zinc alloy layer in the coatings was presumably affected thereby. Differences in reaction behaviour which remain to be
explained were found with the commercial crystals and strain-annealed enamelling-iron crystals of the same orientation. Normal reaction effects were found on enamelling-iron crystals with other orientations such as (421), (311), (210), and (221).
The determination of the composition of slurries by the measurement of thermal-neutron-capture gamma radiation
Authors: Dibbs H P , Dalton J L , Nargolwalla S S
Published: March 2018

A study has been made of the application of thermal-neutron-capture gamma radiation to the determination of the composition of aqueous slurries of iron oxide, cupric oxide, zinc oxide, sulphur, and silica. In general, a linear relationship was found between the
solids content of the slurry and the prompt-gamma-ray counts from hydrogen and from the solid phase, and an equation is presented that predicts the variation of the prompt-gamma-ray counts from hydrogen with the composition of the slurry
Hydrogen-atmosphere galvanizing of iron-base alloys
Authors: Sebisty J J , Ruddle G E
Published: March 2018

Series of iron-base alloys containing manganese, phosphorus and silicon were galvanized in a hydrogen-atmosphere apparatus over a range of time and temperature conditions. Manganese in amounts of 0.17, 0.50 and 1.17% failed to exert any prominent effect on
coating formation. Phosphorus -containing alloys (0. 01, 0.042, 0.069, and 1.1% P), exhibited relatively high galvanizing reactivity which was characterized by increasing unevenness in iron-zinc alloy growth with increasing phosphorus content and immersion time. The reactivity of the
silicon-containing alloys (0.03, 0.08, 0.21, 0.91 and 3.4% Si) generally followed established behaviour but with some significant anomalies. Most notable was a reaction rate inversion in going from the normal galvanizing temperature of 450°C (840°F) to 470°C (880°F). At this
higher temperature, the coating microstructures were significantly altered towards thinner, more compact, iron-zinc alloy layers.
Kinetics of cobalt cementation on zinc
Authors: MacKinnon D J
Published: March 2018

Kinetics of cobalt cementation on zinc sheet from solutions of cobalt sulphate have been investigated with respect to temperature, stirring velocity, and acidity. The effect of buffered solutions on the reaction rate has also been determined. The rate of the
cementation reaction was found to be strongly influenced by the presence of metallic ions other than cobalt in the solution. This effect is interpreted in terms of "alloy" formation, whereas the difficulties encountered in cementing cobalt in the absence of metallic ions is explained in terms of
cobalt deposition overvoltage, hydrogen overvoltage, and inhibition by co-deposition of zinc.
Plume dispersion research at natural-gas sulphur-extraction plants
Authors: Lee G K , Whaley H , Gainer J G
Published: March 2018

The rise and dispersion have been determined for four plumes emitted by three natural-gas sulphur-extraction plants in Alberta. This report describes the data acquisition techniques employed and gives a preliminary evaluation of the results. At one plant, two
plumes were studied, one under inversion conditions and the other under limited mixing conditions. One plume from each of the other two plants was studied under neutral conditions. The results indicate that the standard deviations of plume spread cannot be reliably estimated for limited mixing
conditions and that plume behaviour is strongly influenced by local topography.
A computer program for automatic mesh generation for the 2-d finite element program WILAX
Authors: Toews N A , Yu Y S
Published: March 2018

This report describes a system of three computer programs (MSHGEN, MSHPLT and WXCONV), developed at the Mining Research Centre (MRC), for 'automatic' input data generation for the two-dimensional finite element program WILAX (l). These programs have been
successfully used at MRC for the stress analysis of mining oriented problems, such as the analysis of open-pit slopes or underground openings. Meshes that formerly took several . weeks of tedious work to prepare and check can now often be finished in a day or two. With some minor modifications this
system can be easily adapted to most two dimensional finite element programs
The hydrocracking of residual oils and tars part 6: catalyst de-activation by coke and metals deposition
Authors: McColgan E C , Parsons B I
Published: March 2018

The report described the effect of metals and mineral concentration on the de-activation and regeneration characteristics of a cobalt molybdate hydrocracking catalyst. Two feed stocks were used, (a) Athabasca bitumen (high in metals and residual minerals),and (b)
Leduc pitch (low in metals and residual minerals). The Conradson Carbon Residue values for both feed stocks were similar, in the range 13 to 15 wt %. The experiments were undertaken in a bench-scale flow system with bottom feed. In this mode of operation low-boiling material present in the feed,
or produced in the course of reaction, vapourizes, collects as bubbles and passes quickly out of the reaction zone. High-boiling material remains in the liquid phase and progresses through the reactor by displacement. All experiments were made at a liquid-hourly-space-velocity of 1.05 and a pressure
of 2000 psi. Under the conditions of the tests, the primary cause of catalyst deactivation was found to be the fouling of the surfaces by tarry-coke deposits. There were no measurable differences in the initial rate of de-activation observed between the high-metals and low-metals feed stocks.
Successful regeneration of the catalyst, however, was only possible with the low-metals and minerals feed stock (the Leduc pitch). The metals and minerals incorporated in the coke deposits obtained with the Athabasca bitumen adhered to the surfaces of the catalyst in the oxidative-regeneration
process and reduced the activity considerably.
Hypereutectic aluminumsilicon alloys produced by hot compaction of atomized powder
Authors: Skelly H M , Dixon C F
Published: March 2018

The main objects of this investigation were: (1) to determine whether a fine dispersion of primary silicon phase could be obtained in hypereutectic aluminum-silicon atomized powder without adding nucleation catalysts to the melt; (2) to determine whether the
atomized powders could be consolidated by hot pressing. Atomized powders of A1-25% Si, A1-35% Si and A1-45% Si alloys containing a fine dispersion of silicon were successfully produced without the use of nucleation catalysts. The powders were consolidated to densities Close to
theoretical by hot pressing at temperatures of 400°C (750°F) and 550°C (1020°F) and pressures of 38,000 psi and 81,000 psi. Some properties of the powders and of the compacts produced from them were determined.
Composition et propriétés des argiles et des schistes argileux à céramique du Québec
Authors: Brady J G , Dean R S
Published: March 2018

Forty-one representative samples of clays and shales were investigated by various firing methods and by X-ray diffraction, differential thermal analysis and chemical analysis. In addition, thirteen of the samples were studied by thermogravimetric analysis,
thermal expansion and plabticity measurements, to determine their processing problems. The results show that, with the exception of some refractory kaolinrich samples occurring on the Canadian. Shield which have a white to brown fired colour, the ceramic clays and shales of Quebec are common,
heterogeneous, mainly red-firing materials. Most of the clays are suitable only for making common brick and tile because they have short firing ranges and high fired shrinkages at temperatures where they become dense and very hard. As a rule the shales are more suitable than the clays for making
dense facing brick, because they usually have longer firing ranges. The Quebec Group shales are more refractory and usually have more plasticity and fewer processing problems than the Utica, Lorraine, Rockcliffe and Queenston shales of the St. Lawrence Lowlands. Some of the Quebec Group shales are
probably suitable for the manufacture of sewer pipe. The majority of the kaolin-rich samples, as they occur, are not suitable for ceramic products; many are contaminated with minerals containing iron. The principal clay minerals in the common clays and shales are illite and/or chlorite. The majority
of these samples contain mixed layer systems involving combinations of illite, and/or chlorite, with an expandable phase. Kaolin is a principal component of the kaolin-rich samples only. The principal non-clay minerals are quartz, feldspar, calcite, dolomite and pyrite. The principal constituents in
thirteen fired specimens are quartz and feldspar with lesser amounts of cristobalite, mullite, hematite and rutile.
Mechanism of low-stress brittle fracture in normally ductile materials
Authors: Trudeau L P
Published: March 2018

A mechanism is suggested for brittle failures, in service, from small flaws in normally ductile materials which exhibit an impact energy transition behaviour. The theory suggests, and experiments confirm, that the minimum defect size required for fracture may be
more than an order of magnitude smaller than the average size required. The necessary conditions for such a fracture are: (1) the material must exhibit dynamic nil-ductility behaviour under the conditions of stress, temperature and section size that apply in the structure; (2) there must be a defect
of sufficient size to give rise to a stress field capable of sustaining a running fracture; and (3), at the base of this stress raiser, there must be a metallurgical imperfection or operative process capable of giving a fast increment of rupture over a microscopic distance comparable to the plastic
zone size of a running fracture. The critical flaw size can be calculated from the dynamic K10 . Impact loading is not necessary for initiation.
Some effects of pressure on consumable electrode arc melting
Authors: Suiter J W
Published: March 2018

The effect of pressure, in a consumable electrode arc furnace, on the weight of metal melted per unit of energy dissipated was investigated while melting titanium electrodes of negative and positive polarity and steel electrodes of negative polarity. Provided
that the arc length was sufficiently short, the weight of metal melted per unit of energy dissipated increased continuously as the pressure of argon was decreased from 650 mm Hg to 1 x 10 -2 mm Hg.
Measurement of the residence time of slurries in an aerator tank, using radioactive tracers
Authors: Gibson E C , Eichholz G G
Published: March 2018

Radioactive silver was used as a tracer to investigate the flow characteristics and the effective residence times of a slurry in a laboratory tank used for aeration in pilot plant flotation operations. It was found that short-circuiting occurred with the air
inlet in its original position, and satisfactory mixing was established by relocating the inlet pipe. The interpretation of retention time data is discussed briefly. Measurements of this type can be carried out during normal operation of the plant and at negligible cost.
On the occurrence of & carbide in iron
Authors: Boswell F W C
Published: March 2018

Quenched and aged alpha iron specimens have been examined by electron diffraction after polishing and etching to leave carbide particles in relief. Specimens aged at 200°C for 2 hours gave patterns typical of hexagonal epsilon iron carbide and those aged at
400°C for 1 hour gave patterns typical of cementite
Surface exchange reactions of silver and its ions
Authors: Sandor J E
Published: March 2018

The exchange reactions between silver and its ions in solution have been investigated by the use of radioactive tracers. Silver of highest purity was cleaned carefully and immersed into a radioactive silver nitrate solution. The course of the early adsorption
process and subsequent diffusion of the ions into the interior of the metal was followed in detail, and the diffusion coefficient at room temperature was calculated. The penetration depth was determined by controlled electro-polishing of the metal, and the reverse movement of active ions from the
metal into inactive solutions was also observed.
A study of mercury-cathode membrane cells for the electrolytic reduction of uranyl solutions
Authors: Kim J W , Simard R
Published: March 2018

Bench-scale horizontal cation-permeable membrane cells were constructed .to study the effect of cell dimensions on the efficiency of electrolytic reduction of uranyl sulphate solutions flowing continuously over a mercury cathode. Current efficiencies were
determined for various cells having length-to-width ratios of 10/1 to 40/1, and for catholyte solutions containing from 20 to 100 g U 3 0 8 /1 in sulphuric acid. Optimum current density and solution flowrate were determined under these conditions. The effects of the nitrate and chloride ions were
briefly examined.
Criteria of ductility in uniaxial tension
Authors: Bleakney H H
Published: March 2018

The merit of reduction-in-area as a criterion of quality in metals is shown to lie in its influence on breaking stress, but the virtue of elongation is not easy to find. In order to assess the value of elongation, either as a measure of quality or as a guide to
design, it will be necessary to separate the overall deformation occurring in tension tests from the localized deformation associated with localized reduction in area. The obstacles to a successful solution of this problem have been shown to be more formidable than- is generally appreciated, and a
new solution to the problem has been suggested. This solution involves a device by which an electric circuit is broken when the particular value of strain is reached that is to be taken as the point of separation between general and localized deformation. The report presents results from a number of
tests on both low-carbon and alloy steels . These results indicate that the selected criterion of separation is accurately identified by the proposed method; that it gives a satisfactory compromise between too much localized deformation on the one hand, and too little general deformation on the
other; and that it is simply and practicably applicable to routine tests.
The measurement of the surface area of uranium dioxide powder
Authors: Gorla P R
Published: March 2018

A comparative method has been developed for the determination of surface areas of UO: powder. The method depends on the sorption of phosphate ions from a solution containing P-32 labeled Nall2PO4 on the powder surface. By comparison with samples of known surface
area, measurements have been obtained in the range 1.0-14 meter2/gm. The internal consistency of the method is better than ±2% and agreement with measurements by the 13ET method averages around ±5%. The method is simple and fairly rapid, and can be adapted to irradiated
material
Fluorescence effects in ion exchange resins
Authors: Flint T R , Eichholz G G
Published: March 2018

Fluorescence under ultraviolet illumination has been in anion and cation exchange resins when in the unloaded observed state. This fluorescence decreases rapidly in intensity as the resin is loaded and this process has been shown to offer a practical method for
controlling the loading and elution cycles in ion exchange operations. The relative effectiveness of different resins and various ions on this fluorescence quenching process has been determined and some correlation has been found between quenching efficiency and ionization potential of the elements.
The measurements have shown adequate stability and reproducibility for industrial control applications.
Towards a common basis for the sampling of materials
Authors: Visman J
Published: March 2018

Dans de nombreux domaines de recherches, on a besoin d'une méthode générale poux évaluer à l'avance la précision d'échantillons tirés systématiquement de lots de matériaux qui ne sont pas des mélanges au
hasard. Les matériaux et les variates peuvent varier considérablement et los circonstances dans lesquelles les échantillons sont pris peuvent varier beaucoup, mais les causes de variation de la valeur de l'échantillon sont limitées. Deux facteurs ne dépendent que de la
nature du lot: la variation aléatoire et la « ségrégation » On peut les évaluer comme variances partielles, d'après une expérience spéciale ou bien d'après des connaissances antérieures si l'on connaît la composition et la distribution du
matériau. Les autres facteurs de la précision de l'échantillon sont: le nombre (N) des prélèvements obtenus de toutes les parties du lot, et la grandeur (lei ) de l'échantillon total; ces variables opératoires peuvent dans une certaine mesure être
modifiées à volonté par l'échantillonneur. L'équation s2 = A/W 4. B/N est valable quelle que soit la forme de la distribution de la variate. Elle s'applique en général pour des estimations de premier ordre de la limite sup4rieure de la variance
d'échantillonnage (s2) Le degré de ségrégation est exprimé. par z2 B/A. L'auteur propose un "tableau d'échantillonnage" expérimental pour démontrer les rapports ci-dessus, dans le cas de distributions binomiales de la variate. Dos expériences avec ce
tableau confirment que ces équations s'appliquent aux conditions d'échantillonnage systématique aussi bien qu'a l'échantillonnage au hasard, et qu'on peut les utiliser pour évaluer et prédire la précision d'échantillonnage, pour un grand nombre de
matériaux.
The mineral constitution of some ordovician shales of eastern and southern Ontario
Authors: Sadler A G
Published: March 2018

Ordovician shale specimens from formations belonging to the Richrnondian, Maysvillian, Edenian, and Chazyan stages were sampled from several localities in Ontario. The materials were subjected to various physical and chemical treatments, and examined by DTA,
chemiçal and X-ray diffraction techniques. The major mineral constituents in the three Queenston shale samples of the Richmondian stage were found to be illite, chlorite, quartz, and calcite. Dolomite was identified as a minor mineral constituent in two of the samples, and X-ray and chemical
analyses suggested the presence of minor amounts of a sodium (or sodium-calcium) feldspar. The mineral types present in all three samples were almost identical and the specimens differed only in the relative amounts of each component. The Dundas and Carlsbad shale samples of the Maysvillian stage
had similar mineral constitutions to the Queenston specimens. In addition, small amounts of pyrite and organic matter were identified in the Carlsbad shale. The results and calculations based on chemical tests showed that the samples differed from the Queenston shales in having a higher proportion
of ferrous and a lower proportion of ferric ions.The shale from the Billings formation of the Edenian stage resembled the Carlsbad material mineralogically however, the sample contained more organic matter and pyrite, and calcite was present only as a minor constituent. The Rockcliffe shale, which
belongs to the Chazyan stage, also contained illite, chlorite, quartz, calcite and dolomite. Chemical and X-ray results indicated the presence of appreciable amounts of a potassium feldspar. Suggestions for future work in this field have been put forward.
Uranium in non-ferrous metals
Authors: Thomson R , Edwards J O
Published: March 2018

The use of uranium metal in non-ferrous metallurgical practice is discussed with reference to its alloying behaviour and chemical activity, and it is suggested that the more promising applications are in the treatment of molten metals to combine with impurities.
Mines Branch work along these lines is described for copper, zinc, magnesium, aluminum and nickel alloys. It is shown that a copper-uranium master alloy (25% U) successfully deoxidizes molten copper without detriment to the electrical or mechanical properties of the product at residual uranium
levels of up to 0.8 wt %. Additions of uranium to a brass in amounts greater than the lead impurity content were found to remove the deleterious effect of lead on hot-workability. Similar deoxidizing and malleableizing effects were found with uranium additions to nickel. It is thought that
uranium forms stable intermetallic compounds with many impurity elements, thus a significant malleableizing effect can be expected in the presence of other elements besides lead. The effects of uranium on hot dip galvanizing and on grain refinement in magnesium and aluminum alloys have been
evaluated briefly, but no beneficial effects were noted.
Resolution of the operating variables of a small hydrocyclone
Authors: Pilgrim R F , Ingraham T R
Published: March 2018

Application of dimensional analysis and experiment to the operation of a hydrocyclone yielded an equation of the form: Q Kipra-svs bra-up This equation shows that the volume throughput Q is a function of the pressure differential P, the density ô and the
viscosity p of the medium. The constant K, and the coefficients of the pressure differential, density and viscosity were shown by statistical analysis to be relatively simple functions of the dimensions of the body and orifices of small glass hydrocyclones used with liquid
media.
Kinetic studies of the thermal decomposition of ferric sulphate and aluminum sulphate
Authors: Warner N A , Ingraham T R
Published: March 2018

Kinetic studies were made of the thermal decompositions of ferric sulphate and aluminum sulphate. The reaction product gases were swept from the samples. Cylindrical pellets prepared front chemically pure anhydrous powders were used, and mathematical corrections
were made to relate the reaction rate to the area of the interface between the undecomposed sulphate and the oxide product. The interface is the local of the reaction. The rate of the decomposition reaction is proportional to the area of this interface. Studies on ferric sulphate have shown that the
rate of decomposition is also directly proportional to the difference between the equilibrium pressure of sulphur dioxide (or oxygen) over the sample and the partial pressure of sulphur dioxide (or oxygen) in the gas stream. The activation energies are 19.9 kcal. and 64.0 kcal. respectively for the
ferric sulphate and aluminum sulphate decompositions. No oxysulphates were detected as intermediates in the transition front the normal sulphates to the oxides.