Material Designers Research Articles

Color research and its application to the design of instructional materials

This paper is divided into three major sections: Color as Seen—Physiological; Color as Seen—Psychological; and Color and Learning. The first section deals with color adaptations and the effects of color on acuity and relates these to the design of instructional materials. The second section covers color meanings and preferences, as well as color harmony and the relationships of these factors to the design of instructional materials. The third section provides an overview of research on color and learning. It includes the effects of color on attention, search tasks, other objective and non-objective measures of learning, and the use of color for cathode ray tube (CRT) displays. Although the measurable effects of color may be slight, colored materials are preferred and they are used almost universally. Therefore, designers of instructional materials need to use color wisely by paying attention to the physiological and psychological effects of color and the effect of color on learning.

On the Consistency of Complex Moduli for Transversely-Isotropic Viscoelastic Materials

The ability of advanced composite materials and structures to damp vibration is important in many applications. Use of the complex modulus approach to represent the dissipative properties of transversely-isotropic materials, such as unidirectional fiber-reinforced composites, requires the definition of a set of 5 (imaginary) loss moduli in addition to the 5 (real) storage moduli needed to describe the elastic behavior. In practice, designers of composite materials rarely have experimental data for all 5 loss moduli, and must assume values for the remaining moduli in their analyses. If values for these unknown loss moduli are specified arbitrarily, physically unreasonable behavior can result. This paper develops the conditions necessary for physical consistency of the complex moduli of transversely isotropic materials.

Effective Thermomechanical Behavior of Plain-Weave Fabric-Reinforced Composites Using Homogenization Theory

A micromechanical analysis is presented to obtain the effective macroscale orthotropic thermomechanical behavior of plain-weave fabric reinforced laminated composites based on a two-scale asymptotic homogenization theory. The model is based on the properties of the constituents and an accurate, three-dimensional simulation of the weave microarchitecture, and is used for predicting the thermomechanical behavior of glass-epoxy (FR-4) woven-fabric laminates typically used by the electronics industry in Multilayered Printed Wiring Boards (MLBs). Parametric studies are conducted to examine the effect of varying fiber volume fractions on constitutive properties. Nonlinear constitutive behavior due to matrix nonlinearity and post-damage behavior due to transverse yarn failure under in-plane uniaxial loads is then investigated. Numerical results obtained from the model show good agreement with experimental values and with data from the literature. This model may be utilized by material designers to design and manufacture fabric reinforced composites with tailored effective properties such as elastic moduli, shear moduli, Poisson’s ratio, and coefficients of thermal expansion.

Effect of tow alignment on the mechanical performance of 3D woven textile composites

Three-dimensional (3D) woven preforms are currently being considered for use as primary structural components. Lack of technology to properly manufacture, characterize and predict mechanical properties, and predict damage mechanisms leading to failure are problems facing designers of textile composite materials. Two material systems with identical specifications but different manufacturing approaches are investigated. One manufacturing approach resulted in an irregular (nonuniform) preform geometry. The other approach yielded the expected preform geometry (uniform). The objectives are to compare the mechanical properties of the uniform and nonuniform angle interlock 3D weave constructions. The effect of adding layers of laminated tape to the outer surfaces of the textile preform is also examined. Damage mechanisms are investigated and test methods are evaluated.

Advances in aluminium alloy products for structural applications in transportation

This paper describes the needs of the aviation and automotive markets for structural materials and presents examples of developments of aluminum alloy products to fill these needs. Designers of aircraft desire materials which will allow them to design lightweight, cost-effective structures which have the performance characteristics of durability and damage tolerance. Their needs are being met by new and emerging materials varying from Al-Li alloys for thick structure, high-strength plate and extrusions for wings, and new monolithic and aluminum-fiber laminates for fuselages. Increase in fuel economy because of lighter weight structure is the driving force for aluminum alloys in the automotive market, and cost is extremely important. Mechanical properties for automotive use also depend on the application, and corrosion resistance must be adequate. For «hang-on» components such as fenders and hoods, formability is typically the limiting mechanical property. Strength must be adequate to resist denting at a thickness which offers cost-effective weight savings over steel. Because formability often decreases with increasing yield strength, alloys which are highly formable in the T4 temper and which age harden during the paint bake operation were developed. Alloys such as 6009 and 6010 are now being challenged by 2008, 6111 and 6016. Body structure components must be made from materials which absorb energy and fail gracefully during a crash. Such components for an automotive space frame are being die cast from an Al-Si-Mg alloy. These ductile die castings are joined to thin 6XXX extrusions which must combine formability, strength, ductility and the ability to deform plastically on impact. Bumpers must combine strength and adequate formability; in the event that current alloys are inadequate for future needs, a new 7XXX alloy offers an improved combination of properties

Judgments of Hazard, Risk, and Danger: Do They Differ?

There were three purposes of the present research. The first was to test whether some of the discrepancies found in the hazard and risk perception literature were due to differences between the connotations of the terms hazard and risk. The second purpose was to examine the relationship between willingness to read warnings and generalized cautious intent, as well as other relevant variables suggested by past literature. The third purpose was to examine the relation between objective measures of injury (e.g., frequencies of hospital emergency room admissions) and people's subjective perceptions. The results showed that the expressions of hazardous, risky, dangerous and hazardous-to-use connote the same meaning to lay participants. Strong intercorrelations were found between overall unsafeness (a composite of the four hazard-risk expressions), injury severity, cautious intent, and willingness to read warnings. While injury likelihood played a small part in the prediction of willingness to read warnings, the results indicated that overall unsafeness (and severity of injury) play the foremost role in people's judgements of whether to read warnings and to act cautiously. No relationship was observed between objective measures of injury frequency and people's subjective perceptions of injury likelihood which is taken as a further indication that people do not readily use injury likelihood in their judgements of product safety. The implications are two-fold. First, the results suggest that lay persons do not interpret the term risk in the same way as do experts. These results suggest that other terminology and language may be needed to express probability to lay persons. Second, the results suggest that designers of warnings and educational materials should focus their attention to ways that appropriately communicate how badly a person can get hurt, rather than (or to a lesser extent) the likelihood of getting hurt.

Low Pressure Thermal Deposition of Metal Matrix Composites

The combination of broad materials flexibility and rapid solidification rates achievable during controlled thermal deposition processes provide material designers with exciting new opportunities. Titanium and aluminum alloys have been melted and deposited as dense (90%) sheet and foil products in a controlled low pressure, inert atmosphere chamber. A high frequency (rf) plasma torch is used for a wide range of powder feed sizes. Conversions of powder to deposit have exceeded 90% yields. The deposition chamber accommodates a 1.2 m diameter by 1.2 m wide rotating mandrel. The mandrel drive system and torches are controlled to achieve uniform deposit thickness and effective heat extraction. To produce composite products, the programmable mandrel drive has been coupled with a continuous filament feed system to achieve precise spacing of fiber reinforcements. Initial fiber winding and matrix deposition trials utilized surrogate metal fibers, IN909 and stainless steel, until suitable high strength ceramic fibers became available. The spectrum of materials included metal/metal composites and particulate reinforced matrices. Deposits were characterized with respect to density, composition and metallurgical structure. Aluminum deposits were hot rolled to full density. Preliminary mechanical properties were determined. An overview of Alcoa work to date will be presented and some future composite materials synthesis opportunities will be described.

Structuring Knowledge Bases for Designers of Learning Materials

Designers of interactive video training packages need access to multiple sources of information to be able to create exciting materials for learning or training. Hypertext allows dynamic linking of...

Implementation problems of Computer Based Training within the U.K. Government's Youth Training Scheme

With the introduction of the computer as an educational medium, Self[1] amongst others, has argued that four classes of people are now involved in Computer Base Training (BT): the medium designers, the material designers, the teachers, and learners. The degree of control is potentially, therefore, shared among all four. The extent to which this actually happens varies considerably and to a large degree depends on the users' (teachers' and learners') understanding of how to use such technology, as well as how it may or may not contribute to their overall educational objectives. Over the past four years, the authors have been examining two Government-funded projects concerned with the development and transferability of CBT within the Youth Training Scheme. In both projects. a case study approach was adopted for the purposes of our research. Our study has shown that within this particular learning milieu, there is a fifth class involved in this notion of ‘shared control’; the computer system's administrator or instructor. We have noted that the latter plays a significant role in determining how CBT is used within training. As the perceived expert, he or she is responsible not only for the provision of technical support, but also for the selection of, and access to, courseware. In this paper, we illustrate how CBT has been introduced into two different training contexts, our ease studies, and discuss the implications for the ultimate implementation of CBT as a training medium within youth training programmes.

Learning english with an invisible teacher: An experimental video approach

We are currently experiencing a period of experimentation and exploration in the field of second language education. In the attempt to find new approaches for enhancing second language acquisition in the classroom, some educators have focused on emerging technologies, in particular on the exploitation of the video medium. Even though television has been with us for 40 years, we have only recently begun to seriously explore its use in second language learning. The widespread availability of video tape has had the effect of a catalyst in making video more available to materials designers and teachers. This paper reports on an experimental class in English as a second language for beginning learners. The teaching approach used in the class was based on an innovative video series developed by Caleb Gattegno (1977). The tapes in this series are particularly unusual in that no teacher appears on the screen. Instead, the focus is on students as they learn, and the viewer learns along with them. We will evaluate the learners' progress in the class in the light of standard proficiency tests and will report our own observations and the views expressed by the learners themselves.

How teachers design their materials: Implications for instructional design

Research on teacher thinking and teacher planning conducted over the past few years suggests that teachers rarely proceed in a “systematic” fashion when planning or carrying out instruction. What happens when teachers become designers of instructional materials? In a series of studies of teachers and novice instructional designers, data were collected on: the form taken by initial ideas for materials; elements involved in initial thinking; constraints perceived; the train of the design process; and reflections on the design after completing it. Results showed that prescriptive models of how instructional design should proceed frequently do not match the reality of instructional design in practice. Several changes in instructional design procedures might take these differences into account: designers might engage in “synectics” sessions, for example, rather than focusing immediately on objectives. And incompleteness in a design appears to have particular fascination for instructors. Finally, the studies point out the need for more careful and comprehensive treatments of what “design” is, and of why some are more successful at it than others.

From seeing and hearing to remembering: A conception of the instructional process

This article presents a conceptual schema of the instructional process which is intended to make a number of relevant findings from research more readily understood and applied by designers of instruction and instructional materials. It is based on severll summary sources of research-based findings and principles from the perception, memory, and concept formation literature. The basic conception is that learning is the product of an ongoing interactive process between learner and environment, and that instruction is a temporary and purposeful intervention in that process, the aim of which is the optimization of the learner-environment interaction.

Bases for the selection of background colors for transparencies

When designers of visual materials want to add color to their black-and-white transparencies, they are concerned about how to select the proper colors. Are there specific colors, transmissions or densities, or brightnesses that provide the best viewing conditions? What background colors will make the message most legible? Solutions to the problems of selecting background colors for projected visuals are related to the effect colors have on visual acuity. This study attempts to answer the question: What background color' should be used on projected materials to meet the legibility needs of the viewer?

The structure of english: The language to be learned

The material in this paper has been culled from many sources, espe cially in psychology, semantics, linguistics and pedagogy. This organiza tion of the structure of English with an eye to maximal rationalization of its spelling is only in small part my own. First there were the pioneering insights of Orton, then the prodigious work of organization and detail of Gillingham and Stillman through seven editions from 1930 till 1964—a monumental contribution. Sally Childs, through her Spelling Curriculum published in 1954, supplemented by other works and soon, happily, to appear in a revised edition, has focused attention on reorganization of approach and refinements of pedagogic technique in line with new develop ments in psychology and linguistics. Their work has enormously facilitated the practical implementations of the designers of texts, guides, materials and workbooks. They have inspired and guided the programs of schools and clinic services and such complete programs as that of the Texas Scottish Rite Hospital Language Unit in Dallas and the Remedial Reading Center in Rochester, Minnesota. Those of us who have come into the field on tributaries from the '30's to the '60s, have been able to join the main stream, each in his or her own way, for such is the structured flexibility of this approach that there is ample room for individuality. The constraints are provided by the nature of the language to be taught, the ways a human being learns, and the unique needs of language-disabled learners as a group and as individuals. The focus in this paper, by request of the group for whom it was written, is on the first of these constraints, especially the spelling patterns of English, with accommodation to it, in the light of the other strictures, by one teacher and pupil working together. Within practical limits one never can—nor should one try to—"tell it all." If what Dan and I have coordinated here, with the help of those on whose shoulders we gratefully stand, is of help to some readers and their students, we shall be glad. Better yet, other teams can improve and elaborate what we suggest here. The field is open.

A New Area Sampling Frame and Its Uses

A REA sampling for agriculture's uses in the United States has been identified with the master sample materials prepared at Iowa State University in the early 1940's. The area method of sampling involves subdividing the entire area to be sampled in each state into sampling Sampling based on the master sample frame refers to the use of areas of land as sampling In the preparation of this frame, three types of land areas were identified based on incorporation and density of population. The county highway maps were used for this purpose. Thus, three strata, (1) open country, (2) urban places, and (3) rural places, were identified in the sampling material. Also, the open country was divided into units which were called units. The word was used to convey the fact that a count of farms and dwellings on the maps was made for each unit. For each count unit, a number of sampling units, or segments, was assigned, based on the farm count. While these three strata plus geographic stratification were adequate for the relatively homogeneous agriculture of the early 1940's because of the general or diversified nature of the family farm, rapid changes have occurred which make the degree of stratification inadequate, especially in the western states. This inadequacy was recognized early by the designers of the master sample materials and efforts were started in the late 1940's to stratify those states west of the 100th meridian. However, this project was never completed because of diversified interests and lack of funds.

Lubricants for Nuclear Reactors

The earlier British carbon-dioxide-cooled, graphite-moderated power reactors were designed to operate without lubrication. This was necessitated by lack of knowledge of the effects of radiation and other reactor operating conditions on lubricants, and of the degree of compatibility of lubricants with reactor materials Investigations carried out over the past few years of the effects of nuclear radiation on many types of lubricant have shown that it is possible to produce materials capable of lubricating some reactor components. In order to further the development of such lubricants the U.K.A.E.A. and the nuclear manufacturing groups have co-operated in providing lubricant manufacturers with details of design and operating conditions of reactor components which it is desirable to lubricate In this paper is described the range of operating conditions which lubricants are expected to encounter in different reactors, with particular emphasis on the C02-cooled, graphite-moderated reactor. Nuclear lubricant requirements proposed by the U.K.A.E.A. to cater for many applications are also discussed With this information available it is now possible to assess realistically the types of test facility necessary for the evaluation of nuclear lubricants. Such test facilities are described. They include irradiation sources, a test rig for running under irradiation conditions, various test rigs to simulate reactor operating conditions for testing products both before and after static irradiation, and other specialized equipment The effect of radiation on both conventional and nuclear lubricants is described and the use of ‘anti-rads’ illustrated. Attention is drawn to other desirable properties of nuclear lubricants such as temperature stability, low volatility and compatibility with reactor and fuel-can materials Designers of reactor machinery have taken, and will increasingly continue to take, advantage of the developments in lubricants but, while still further advances in lubricant quality will be made, some components, particularly of the more advanced types of reactor, will probably continue of necessity to be operated without lubrication