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Geometry is one of the most important foundations of Iranian art and architecture, which can be seen in the magnificent buildings left from the past that are important in architecture. One of the most important buildings of Iran from the Zandiyeh Era (250 years ago) is Vakil Mosque, which is located in Shiraz. Vakil Mosque is a sacred and Islamic building in Iran, which is the aim of this article to investigate and find geometry in the architectural body of this building. In the current research, descriptive-analytical methods were used to collect data. Then I studied the geometrical drawings of this mosque, which some of the most important books of Muslim scholars in this field have been studied to obtain the geometry of the plan and elevations of Vakil Mosque, and after many tests and finding acceptable answers, options were proposed as the physical geometry of this sacred building. Finally, I came to the conclusion that the architect or architects of this magnificent building have used their utmost efforts in designing its physical to create golden proportions and regular geometry on it, and this order and geometry is the reason for the glory and strength of this building. The findings of this article can be used along with other similar studies to recognize Iran's architectural works and restore its original Islamic-Iranian identity. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine pre-service elementary school teachers' capabilities of deciding the viewpoint and perspective in geometrical drawing. The study examined geometrical drawings the participants did on isometric paper. This is a case study, a qualitative study method, and the study data were analyzed using written documents. The study sample included 34 senior students in the Education Faculty's Elementary School Teaching Program at a Turkish public university. They were selected from approximately 205 pre-service teachers. The students participated in the study on a voluntary basis. The study results revealed that the pre-service teachers generally had weak skills in geometrical drawing. The participants had better skills in building structures which they saw from the air using unit blocks, and forming a structure of which they had the direct views (left and right; front and back) using unit blocks. However, the participants had weaker skills in drawing the direct views of the structures they had built, recognizing the connections between the left-right views and front-back views of the structures and drawing the structures they built on isometric paper in perspective. [ABSTRACT FROM AUTHOR]

In many cases the design and development of bulk forming processes bases on inefficient trial-and-error procedures consisting of various iterations of numerical and real tests. To address this issue, a new numerical strategy to compensate systematic deviations of bulk-formed parts is deduced. Due to a parameter-based approach, control points allow for a direct mapping between the die and the workpiece. Thus, based on the required part shape, it is possible to directly adjust the die, where any kind of geometrical input data can be provided to derive a systematic compensation. The purely geometrical approach takes into account the entirety of systematical effects regarding deviations in bulk forming. The proposed concept is shown theoretically and moreover validated as well as verified utilizing deviation data of three manufactured industrial bulk-forming parts. [ABSTRACT FROM AUTHOR]

This paper analyses the relation between the precedence of a design method and the justification of the method. A design method is assumed to advance two knowledge claims concerning its domain of application: that it is an effective means for designing and that it is an efficient means for doing so. It is argued that precedence of a method can justify these knowledge claims under two conditions. The first is that precedence, in addition to descriptions of successful design projects realized with the method, also comprises: (1) negative precedence of unsuccessful design projects; and (2) comparative precedence of design projects carried out with other methods rival to the method concerned. The second condition is that the two knowledge claims of a method can be justified by precedence about only exemplar design tasks that represent the full application domain of the method. [ABSTRACT FROM AUTHOR]

Step by step all companies are moving to BIM technology nowdays. It accelerates work and makes efforts of designers more effective. Unfortunately, it is not so easy. Aim of this article is to provide specialists that a moving to BIM technologies with required practical recommendations. [ABSTRACT FROM AUTHOR]

As stated in the sister article that the objective of this study was to explore the low-cycle fatigue and ratcheting failure responses of elbow components through experimental and analytical studies. Low-cycle fatigue and ratcheting damage accumulation in piping components may occur under load reversals induced by earthquakes or thermomechanical operations. Ratcheting damage accumulation can cause failure of components through cracking or plastic buckling. Hence, design by analysis of piping components against ratcheting failure will require simulation of this response with reasonable accuracy. In developing a constitutive model that can simulate ratcheting responses of piping components, a systematic set of elbow experiments involving deformation and strain ratcheting were conducted and reported in the sister article. This article will critically evaluate seven different constitutive models against their elbow response simulation capabilities. The widely used bilinear, multilinear, and Chaboche models in ansys are first evaluated. This is followed by evaluation of the modified Chaboche, Ohno-Wang, modified Ohno-Wang, and Abdel Karim-Ohno models. Results from this simulation study are presented to demonstrate that all the seven models can simulate the elbow force response reasonably. The bilinear and multilinear models can simulate the initial elbow diameter change or strain accumulation, but always simulate shakedown during the subsequent cycles when for some of the cases the experimental trends are ratcheting. Advanced constitutive models like Chaboche, modified Chaboche, Ohno-Wang, modified Ohno-Wang, and Abdel Karim-Ohno can simulate many of the elbow ratcheting responses well, but for some of the strain responses, these models simulate negative ratcheting, which is opposite to the experimental trend. Finally, implications of negative ratcheting simulation are discussed and suggestions are made for improving constitutive models ratcheting response simulation. [ABSTRACT FROM AUTHOR]

This paper presents a formal model of design as a sequential decision process. In the process model, the design process takes discrete steps through a space defined by the extent of the set of designs under consideration, the level of detail of the designs, and the level of fidelity of the analyses the designs are subjected to. At the start the design space is broad, the design detail is low, and the analyses are conceptual. The process finishes with a single point design of full detail subjected to the highest fidelity analyses. Two premises underlie the model; first, that design decision making is a process of simultaneously constructing one's preferences while satisfying them. Second, that design using computational models is a sequential process that starts with low fidelity models for initial trades and progresses through models of increasing detail. These premises are supported by research from the domains of behavioral economics, psychology, judgment and decision making, neuroeconomics, marketing, and engineering design, and are substantiated by the authors’ own experience. The paper summarizes the pertinent literature, synthesizes a preliminary model of the sequential process and how lower fidelity models couple to higher ones, and develops an experimental case study now being used to exercise the model. [ABSTRACT FROM AUTHOR]

A methodology is presented for the estimation of recyclability indicators of product designs. It combines an automated CAD-integrated disassembly sequence generation algorithm and a recyclability assessment module. The algorithm employs collision detection and CAD feature recognition for the extraction of disassembly tiers and sequences of specific components. This information together with the components’ characteristics, including materials, is then processed by the corresponding module, which is capable of providing an initial evaluation about the product's recyclability. The methodology is demonstrated through an industrial case study, involving rear axle designs that are associated to different truck models. [ABSTRACT FROM AUTHOR]

Conceptual design involves coevolution of decisions between functional and physical domains. Different methods prescribe different processes to achieve coevolution, hence are suitable for different kinds of design practices. Analytical Target Cascading (ATC) features successive decompositions followed by coordinated optimizations to improve existing systems. Axiomatic Design Theory (ADT) follows a back-and-forth zigzagging process to create completely new systems. A new coevolution process, which is a hybrid between ATC and ADT, is developed from our Innovative Design thinking (IDT) research. This paper explains its theoretical underpinnings and illustrates its suitability for practices between the two extremes, e.g., innovative design on existing systems. [ABSTRACT FROM AUTHOR]

Costuming and design for theatrical productions requires the creative use of mathematics and mathematical processes. To introduce students to the relationship between mathematics and art in costume design, mathematics educators collaborated with a costuming and design professor from the College Conservatory of Music to create this series of activities based on one expressive element - the hat. A central goal of the series of activities was to help students understand the role of mathematics in both the structural and aesthetic components of the design process. Mathematical Practices, Ratio and Proportion, and Geometry Common Core Standards are addressed. [ABSTRACT FROM AUTHOR]

In many LEDs technical specifications, some parameters, sensitive to the production processes, are described in the ideal situation or they are missing. An important parameter is the peak optical radiant power that, in many realistic cases, doesn't exhibit symmetry to the mechanical axis as specified in LED datasheets thus creating a contradiction with the presented optical distribution characteristic of the emitted radiant intensity. In specific applications, such as measurement light curtains, this information is extremely valuable and helpful to the developer because it indicates possible deviations which should be compensated in this system. In addition, assessing the dispersion degree of the optical radiant power on the peak axis and the angular deviation between this axis and the mechanical axis is of great interest for optical barrier design and implementation. This paper assesses these parameters of 100 samples of a common NIR LED and describes the methodology, experimental setup and interpretation of the acquired data. [ABSTRACT FROM AUTHOR]

The article presents a study on a software program to depict three dimensional (3D) geometric objects through Cognitive Load Theory. It mentions that students who have low spatial ability skills use this software to analyze 3D structure. It highlights purpose of study to produce models and hypothesis for testable outcomes for high school students.

Abstract: In this paper, we propose an approach for generating 3D models of trees from freehand sketches that has the benefit of offering simple and rapid user control. The system generates 3D geometry tree from a 2D sketch, which only need sketch the silhouettes of tree is quicker and more intuitive for a user than having to sketch each branch of a tree. When drawing the sketch, our system using botanical knowledge and the fractals to form trees automatically. We illustrate these ideas by presenting a sketch-based interface, used for sketching tree silhouettes, and construction visual hull using sketch, meanwhile, using botanical knowledge and the fractals to generates branches. Our system allows the user to design trees simple and interactively as compared with rule-based tree modeling systems. [Copyright &y& Elsevier]

A cardinal characteristic can often be described as the smallest size of a family of secardinalquences which has a given property. Instead of this traditional concern for a smallest realization of the given property, a basically new approach, taken in [4] and [5], asks for a realization whose members are sequences of labels that correspond to 1-way infinite paths in a labelled graph. We study this approach as such, establishing tools that are applicable to all these cardinal characteristics. As an application, we demonstrate the power of the tools developed by presenting a short proof of the bounded graph conjecture [4]. [ABSTRACT FROM AUTHOR]

Harvey Hallenberg's detailed re-creation of Claude Claremont's engineering and draftsmanship approach touches on the fundamental need of the student to link the work of the hand with the abstractions of science and mathematics, folded into a context of history. Mr Hallenberg captures the manual and cognitive "constructiveness" of the elementary child as an integral part of learning, through concrete exploration, the process used by classical geometers. Students re-create the origins of math and science by measuring and making geometric drawings using simple tools such as a cork-backed rulem compass, and circular protractor [ABSTRACT FROM AUTHOR]

This paper was developed with the goal of enhancing the mathematical preparation of secondary school teachers in the technological paradigm. It shows how two-variable inequalities can be utilized as models for the construction of geometric objects using the software Graphing Calculator 3.5, produced by Pacific Tech, as a relation grapher. An important aspect of the proposed approach is the joint use of inequalities and data developed in an alternative technological context. [ABSTRACT FROM AUTHOR]

The article discusses the use of an interactive geometry software to teach secondary school geometry. In the article, drawing was referred to as a process that involves the use of freehand tools to create a geometrical object, as many researchers who investigate the teaching and learning of geometry with interactive software make subtle distinctions in several words. It argues that research may provide information about the strategies students use, interpretations students make, and the formal reasoning students engage in while using the technology to learn geometry.

The article discusses the implication of conceptions of angle to middle school mathematics. It presents the significance of the said conceptions, such as playing, drawing and naming shapes, to the development of higher-level geometric understanding. It shows the study with middle school students that seems to have the potential to guide the teaching and mathematics content choices not only of elementary and middle school teachers but of teacher educators as well. It argues that strong geometric knowledge must be rooted in rich conceptual understanding of fundamental ideas such as the angle.

Abstract: The Denaro Complex, part of the Madre de Dios Terrane is composed of metamorphosed pillow basalts, metahyaloclastites, banded metalliferous and radiolarian metacherts, metapelites and redeposited calcareous metasandstones. The basaltic rocks show primary textures, minerals and structures. They are foliated especially in the vicinities of thrust faults, interpreted to have developed during the accretion of the terrane to the Gondwana margin. Composition of relic primary augite and chromite crystals plots into the MORB field of tectonic discriminant diagrams, as do the analyses of whole rock geochemistry, which indicates that these rocks are akin to volcanic rocks erupted along a constructive plate margin (N- and E-type MORBs), probably in a spreading axis-centered oceanic plateau or ridge. The metamorphic assemblages of pumpellyite–actinolite facies bear witness of metamorphism in a frontal accretionary wedge at elevated P and low T conditions, probably related to the Late Triassic–Early Jurassic Chonide event, which has been recognized elsewhere in the Patagonian Andes. [Copyright &y& Elsevier]

The characterization of strongly perfect graphs by a restricted list of forbidden induced subgraphs has remained an open question for a long time. The minimal strongly imperfect graphs which are simultaneous imperfect are only odd holes and odd antiholes ( E. Olaru, [9]), but the entire list is not known, in spite of a lot of particular results in this direction. In this paper we give some new properties of the minimal strongly imperfect graphs. Thus we introduce the notion of critical (co-critical) pair of vertices, and we prove that any vertex of a minimal s-imperfect (minimal c-imperfect) graph is contained in a critical (co-critical) pair, and, in a minimal s-imperfect graph different from a cycle of length at least 5, any vertex is the center of a star cut- set, or, if not, it belongs to a house or a domino. Also, we characterize the triangle-free minimal s-imperfect graphs. (By s-perfect we mean the complement of a strongly perfect graph.) [ABSTRACT FROM AUTHOR]

The article presents the sequential steps in sketching the normal distribution curves. The first step for a sketch of the curve of a normal distribution is to plot the point of the mean and height of the curve. This point would serve as the absolute maximum of the curve and delineate the vertical axis of symmetry of the normal distribution curve. The process of the evaluation of the ratio of y(x) to max[y(x)] that determines the ratio of the height of the curve at each value for x to the maximum height of the curve is presented. The points are then plotted using the determined values and employing only visual estimates.

Abstract: In this note, we prove the uniqueness of the one-point extension of a generalized hexagon of order 2 and prove the non-existence of such an extension of any other finite generalized hexagon of classical order, different from the one of order 2, and of the known finite generalized octagons provided the following property holds: for any three points x, y and z of , the graph theoretic distance from y to z in the derived generalized hexagon is the same as the distance from x to z in . [Copyright &y& Elsevier]

Abstract: In this work we approach the connectivity κ of a kind of product graphs that were introduced by J.C. Bermond et al. in 1984. More precisely, we provide lower bounds for κ, and state sufficient conditions that guarantee these product graphs to be maximally connected or superconnected. A main consequence is that even graphs with low connectivity may lead to highly connected larger (product) graphs. [Copyright &y& Elsevier]

Abstract: Let us denote by the family of bipartite graphs G with m and n vertices in its classes that contain no cycles of length less than or equal to 2t and have maximum size. In this paper the following question is proposed: does always such an extremal graph G contain a -cycle? The answer is shown to be affirmative for or whenever m and n are large enough in comparison with t. The latter asymptotical result needs two preliminary theorems. First we state that the diameter of an extremal bipartite graph is at most 2t, and afterwards we show that its girth is equal to when the minimum degree is at least 2 and the maximum degree is at least . We also give the exact value of the extremal function for and and show that all the extremal bipartite graphs of are maximally connected. [Copyright &y& Elsevier]

Abstract: We study some combinatorial and algorithmic properties of discriminating codes in bipartite graphs. In particular, we provide bounds on minimum discriminating codes and give constructions. We also show that upperbounding the size of a discriminating code is NP-complete. [Copyright &y& Elsevier]

Abstract: This paper introduces the concept of discrete multidimensional size function, a mathematical tool that studies particular graphs called size graphs, aimed at applications in shape analysis. A global method for reducing size graphs and a theorem, stating that discrete multidimensional size functions are invariant with respect to this reduction method, are shown. This result allows us to easily and fast compute discrete multidimensional size functions for applications. [Copyright &y& Elsevier]

Abstract: We consider the squares of intersection graphs of hypergraphs and simple graphs. The Berge-type characterization for squares of intersection graphs of hypergraphs is obtained. The analogue of Whitney theorem for squares of intersection graphs of trees is proved. Using the connection between induced matchings of graph and independent sets of square of line graph, new polynomial solvable cases for the weighted induced matching problem are obtained. [Copyright &y& Elsevier]

Abstract: An edge of a 5-connected graph is said to be contractible if the contraction of the edge results in a 5-connected graph. A 5-connected graph with no contractible edge is said to be contraction critically 5-connected. Let G be a contraction critically 5-connected graph and let H be a component of the subgraph induced by the set of degree 5 vertices of G. Then it is known that . We prove that if , then , where stands for the graph obtained from by deleting one edge. Moreover, we show that either or and around H there is one of two specified structures called a -configuration and a split -configuration. [Copyright &y& Elsevier]

Abstract: Bipartite graphs and are bi-placeabe if there is a bijection such that and for every edge ). We prove that if G and H are two bipartite graphs of order such that the sizes of G and H satisfy and , and the maximum degree of H is at most 2, then G and H are bi-placeable, unless G and H is one of easily recognizable couples of graphs. This result implies easily that for integers p and such that for and every bipartite balanced graph G of order 2p and size at least contains mutually vertex disjoint cycles , unless . [Copyright &y& Elsevier]

Abstract: We construct multigraphs of any large order with as few as only four 2-decompositions into Hamilton cycles or only two 2-decompositions into Hamilton paths. Nevertheless, some of those multigraphs are proved to have exponentially many Hamilton cycles (Hamilton paths). Two families of large simple graphs are constructed. Members in one class have exactly 16 hamiltonian pairs, in another class exactly four traceable pairs. These graphs also have exponentially many Hamilton cycles and Hamilton paths, respectively. The exact numbers of (Hamilton) cycles and paths are expressed in terms of Fibonacci-like numbers which count 2-independent vertex (or edge) subsets on the n-path. This approach is prompted by the fact that the square of the n-cycle is the starting point of constructions. Presented results complement, improve on, or extend the corresponding well-known Thomason''s results. [Copyright &y& Elsevier]

Abstract: In 1976 Borodin conjectured that every planar graph has a 5-coloring such that the union of every k color classes with induces a k-degenerate graph. We prove the existence of such a coloring using 18 colors. [Copyright &y& Elsevier]

Abstract: A rough structure theorem for small separations in symmetric graphs is developed. Let be a vertex transitive graph, let be finite with set for some . We show that whenever the diameter of G is at least , either , or G has a (bounded) ring-like structure and A is efficiently contained in an interval. This theorem has applications to the study of product sets and expansion in groups. [Copyright &y& Elsevier]

Abstract: In this paper we describe how the problem of computing an irregularity strength of a graph may be expressed and solved in terms of constraint programming over finite domains, i.e. CP(FD). We also present some theoretical and experimental results concerning an irregularity strength computed for cubic graphs and graphs. Additionally, we give some remarks on the implementation of our approach in the Oz programming language on the platform of the Mozart system. [Copyright &y& Elsevier]

Abstract: Isometric subgraphs of hypercubes are known as partial cubes. These graphs have first been investigated by Graham and Pollak [R.L Graham, H.Pollak On the addressing problem for loop switching, Bell System Technol. J. 50 (1971) 2495–2519] and Djokovic̀ [D. Djokovic̀, Distance preserving subgraphs of the hypercubes, J. Combin. Theory, Ser B41 (1973), 263–267]. Several papers followed with various characterizations of partial cubes. In this paper, we determine all subdivisions of a given configuration which can be embedded isometrically in the hypercube. More specially, we deal with the case where this configuration is a connected graph of order 4 on one hand and the case where the configuration is a fan on the other hand. Finally, we conjecture that a subdivision of a complete graph of order is a partial cube if and only if this one is isomorphic to or there exists edges of adjacent to a common vertex in the subdivision and the other edges of contain odd added vertices. This proposition is true when the order . [Copyright &y& Elsevier]

Abstract: We define a two-terminal directed acyclic graph (st-dag) characterized by a special structure of its mincuts and call it a nested graph. It is proved that every nested graph is series-parallel as well. We show that an st-dag of order n has exactly mincuts if and only if it is nested. [Copyright &y& Elsevier]

Abstract: It happened in the same year (1856) that T.P. Kirkman and W.R. Hamilton discussed problems of closed circuits in graphs. This paper reports on contributions in the 80 years which followed until the first book on graph theory was written by D. König in 1936. Further mathematicians involved were E. Steinitz (configurations), M. Dehn and E. Heegard (encyclopedia), and A. Sainte-Laguë (zeroth book on graph theory). [Copyright &y& Elsevier]

Abstract: A graph G with no isolated vertex is total domination vertex critical if for any vertex v of G that is not adjacent to a vertex of degree one, the total domination number of is less than the total domination number of G. These graphs we call -critical. If such a graph G has total domination number k, we call it k--critical. We verify an open problem of k--critical graphs and obtain some results on the characterization of total domination critical graphs of order . [Copyright &y& Elsevier]

Abstract: P. Erdös, R.J. Faudree, C.C. Rousseau and R.H. Schelp in [Erdös, P., R. J. Faudree, C. C. Rousseau and R. H. Schelp, The size Ramsey number, Period. Math. Hung. 9 (1978), 145–161] studied the asymptotic behaviour of for certain graphs G, H. There will be given some results when each graph of the pair is a regular one. Namely, in this paper a lower bound for the diagonal induced size Ramsey number of each n-regular graph of order for is presented. Moreover lower bounds for the diagonal induced size Ramsey number and size Ramsey number of is presented as well. One of the results is a generalization of a theorem for given by P. Erdös and C.C. Rousseau [Erdös, P., and C. C. Rousseau, The size Ramsey numbers of a complete bipartite graph, Discr. Math. 113 (1993), 259–262]. [Copyright &y& Elsevier]

Abstract: In this article we study when there exist non-crossing subgraphs in a geometric complement of 2-factor and in a complete bipartite geometric graph. [Copyright &y& Elsevier]

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This article explore a quick-graphing method for parabolas that is similar to the method for graphing linear equations. It employs what one refer to as a modified slope triangle or a modified slope step. Just as slope step helps to find other lattice points when graphing linear equations, the modified slope steps will help to find other lattice points on the parabola quickly when the vertex of the parabola is given. After exploring the method quick-graphing parabolas, students should have a better understanding of quadratics and perhaps a better understanding of the quick-graphing techniques for linear equations. Furthermore, students will have one more technique for sketching accurate graphs of parabolas or finding equations of parabolas from their graphs.

A plane drawing of a plane graph is called a rectangular drawing if every face (including the outer face) is a rectangle. An algorithm to generate all based rectangular drawings with maximum degree three is known. In this paper by generalizing the algorithm we give a simple algorithm to generate all based rectangular drawings having n faces without the degree constraint. The algorithm generates without duplications all rectangular drawings having exactly n faces in O(n) time per drawing. By modifying the algorithm we give three more algorithms to generate all rectangular drawings with certain properties. Those algorithms use O(n) space in total. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(4): 1–8, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10563 [ABSTRACT FROM AUTHOR]

The article discusses the significance of an increasing access to technology in making illustrations of boundedness continuity and differentiability clear in a visual presentation. The study, "On the Behavior of a sine equation," is very useful in illustrating several calculus concepts such as boundedness, continuity and differentiability. The graphs of these functions would be interesting and students having access to graphing calculators, or computer algebra systems will be amused upon plotting them. Also presented is the graphic output of the equation.

Iterative geometric solids are commonly drawn by children as a single side; drawings of non-iterative geometric solids usually show several sides. How will children draw a cube, bearing different designs on each side? Intact classes, 524 children, grades K through 5, were randomly assigned to draw a plain or designed cube. Three judges categorized drawings as showing (a) only one side, (b) a square encompassing more than one side, (c) two or more separated sides, (d) two or more sides, some joined, (e) two or more sides, all joined, (1) unsuccessful attempt at spatial depth or perspective, or (g) reasonably accurate perspective. At all grade levels the plain cube was represented as a square with far greater frequency than was the designed cube. The modal category for the entire sample was "3," two or more sides showing with all sides separated. Perspective drawings, attempted and achieved, were more frequent for the plain cube. [ABSTRACT FROM AUTHOR]

The only social agency providing art instruction at the end of the 18th century was the academy of art, which grounded instruction in the life drawing course, copying, and imitation. Though slow, these methods were successful, but were not ones adopted for use in the common schools then beginning to emerge to meet the educational demands of the Industrial Revolution. Instead a new method based on geometric drawing was invented. Ideological and social factors are examined to explain this occurrence. [ABSTRACT FROM AUTHOR]

This paper presents a new approach to Piero della Francesca's technique based on interpretations of historical sources, archival documents, and new results of scientific and technical investigations of the artist's panel paintings. This investigation leads to specific conclusions about Piero della Francesca's actual technical processes, which show very different methods from the traditional ones of the period. Innovations in carpentry construction; particular choices of materials for the ground preparation layers; a non-Italian use of priming; a definite and geometrical re-use of drawings which were proportionally enlarged (tested by computer simulation); continuous innovations in painting media, all reveal a particular knowledge of the physical and chemical characteristics of materials. All these technical innovations reflect an unusual type of professional organization; the structure of this organization is documented and technical procedures are reconstructed. [ABSTRACT FROM AUTHOR]