Enhancing Physics Education in the National Defence University : A design based research approach in the production of learning material

This research is connected with an education development project for the four-year-long officer education program at the National Defence University. In this curriculum physics was studied in two alternative course plans namely scientific and general. Observations connected to the later one e.g. student feedback and learning outcome gave indications that action was needed to support the course. The reform work was focused on the production of aligned course related instructional material. The learning material project produced a customized textbook set for the students of the general basic physics course. The research adapts phases that are typical in Design Based Research (DBR). The research analyses the feature requirements for physics textbook aimed at a specific sector and frames supporting instructional material development, and summarizes the experiences gained in the learning material project when the selected frames have been applied. The quality of instructional material is an essential part of qualified teaching. The goal of instructional material customization is to increase the product's customer centric nature and to enhance its function as a support media for the learning process. Textbooks are still one of the core elements in physics teaching. The idea of a textbook will remain but the form and appearance may change according to the prevailing technology. The work deals with substance connected frames (demands of a physics textbook according to the PER-viewpoint, quality thinking in educational material development), frames of university pedagogy and instructional material production processes. A wide knowledge and understanding of different frames are useful in development work, if they are to be utilized to aid inspiration without limiting new reasoning and new kinds of models. Applying customization even in the frame utilization supports creative and situation aware design and diminishes the gap between theory and practice. Generally, physics teachers produce their own supplementary instructional material. Even though customization thinking is not unknown the threshold to produce an entire textbook might be high. Even though the observations here are from the general physics course at the NDU, the research gives tools also for development in other discipline related educational contexts. This research is an example of an instructional material development work together the questions it uncovers, and presents thoughts when textbook customization is rewarding. At the same time, the research aims to further creative customization thinking in instruction and development. Key words: Physics textbook, PER (Physics Education Research), Instructional quality, Customization, Creativity

ISO 13567 - The Proposed International Standard for Structuring Layers in Computer Aided Building Design

Layering is a widely used method for structuring data in CAD-models. During the last few years national standardisation organisations, professional associations, user groups for particular CAD-systems, individual companies etc. have issued numerous standards and guidelines for the naming and structuring of layers in building design. In order to increase the integration of CAD data in the industry as a whole ISO recently decided to define an international standard for layer usage. The resulting standard proposal, ISO 13567, is a rather complex framework standard which strives to be more of a union than the least common denominator of the capabilities of existing guidelines. A number of principles have been followed in the design of the proposal. The first one is the separation of the conceptual organisation of information (semantics) from the way this information is coded (syntax). The second one is orthogonality - the fact that many ways of classifying information are independent of each other and can be applied in combinations. The third overriding principle is the reuse of existing national or international standards whenever appropriate. The fourth principle allows users to apply well-defined subsets of the overall superset of possible layernames. This article describes the semantic organisation of the standard proposal as well as its default syntax. Important information categories deal with the party responsible for the information, the type of building element shown, whether a layer contains the direct graphical description of a building part or additional information needed in an output drawing etc. Non-mandatory information categories facilitate the structuring of information in rebuilding projects, use of layers for spatial grouping in large multi-storey projects, and storing multiple representations intended for different drawing scales in the same model. Pilot testing of ISO 13567 is currently being carried out in a number of countries which have been involved in the definition of the standard. In the article two implementations, which have been carried out independently in Sweden and Finland, are described. The article concludes with a discussion of the benefits and possible drawbacks of the standard. Incremental development within the industry, (where ”best practice” can become ”common practice” via a standard such as ISO 13567), is contrasted with the more idealistic scenario of building product models. The relationship between CAD-layering, document management product modelling and building element classification is also discussed.

An Integrated Design Procedure for High Frequency AC Inductors for Inverters

Inductors are important energy storage elements that are used as filters in switching power converters. The operating efficiency of power inductors depend on the initial design choices and they remain as one of the most inefficient elements in a power converter. The focus of this paper is to explore the inductor design procedure from the point of efficiency and operating temperature. A modified form of the area product approach is used as starting point for the inductor design. The equations which estimate the power loss in core and copper winding are described. The surface temperature of the inductor is modelled using heat transfer equations for radiation and natural convection. All design assumptions are verified by actual experimental data and results show a good match with the analysis.

Analysis of Flux Fringing for High-Frequency AC Inductor Design

Design of high-frequency inductors for purposes like Active Front End (AFE) converter filters involves analytical calculations based on methods like area product approach and accurate graphical methods. Once a core with an area product is selected the subsequent calculations of inductance and peak operating flux requires the estimation of reluctance of the magnetic circuit. This in turn demands an estimate of the fringing that will happen in the air gap of the inductor. In this paper we have looked at analytical methods for evaluating fringing flux and compared it with results from finite element method. Different levels of details of modelling the inductor is first considered for this purpose. The end results are compared with experimental measurements of inductance. It is shown that simple fringing flux model can provide accurate models for the inductor design.

From Creative Ideas to New Emerging Ventures: Entrepreneurial Processes among Finnish Design Entrepreneurs

This study focuses on self-employed industrial designers and how they emerge new venture ideas. More specifically, this study strives to determine what design entrepreneurs do when they create new venture ideas, how venture ideas are nurtured into being, and how the processes are organized to bring such ideas to the market in the given industrial context. In contemporary times when the concern for the creative class is peaking, the research and business communities need more insight of the kind that this study provides, namely how professionals may contribute to their entrepreneurial processes and other agents’ business processes. On the one hand, the interviews underlying this study suggest that design entrepreneurs may act as reactive service providers who are appointed by producers or marketing parties to generate product-related ideas on their behalf. On the other hand, the interviews suggest that proactive behaviour that aims on generating own venture ideas, may force design entrepreneurs to take considerable responsibility in organizing their entrepreneurial processes. Another option is that they strive to bring venture ideas to the market in collaboration, or by passing these to other agents’ product development processes. Design entrepreneurs’ venture ideas typically emerge from design related starting points and observations. Product developers are mainly engaged with creating their own ideas, whereas service providers refer mainly to the development of other agents’ venture ideas. In contrast with design entrepreneurs, external actors commonly emphasize customer demand as their primary source for new venture ideas, as well as development of these in close interaction with available means of production and marketing. Consequently, design entrepreneurs need to address market demand since without sales their venture ideas may as well be classified as art. In case, they want to experiment with creative ideas, then there should be another source of income to support this typically uncertain and extensive process. Currently, it appears like a lot of good venture ideas and resources are being wasted, when venture ideas do not suite available production or business procedures. Sufficient communication between design entrepreneurs and other agents would assist all parties in developing production efficient and distributable venture ideas. Overall, the findings suggest that design entrepreneurs are often involved simultaneously in several processes that aim at emerging new product related ventures. Consequently, design entrepreneurship is conceptualized in this study as a dual process. This implies that design entrepreneurs can simultaneously be in charge of their entrepreneurial processes, as they operate as resources in other agents’ business processes. The interconnection between activities and agents suggests that these kinds of processes tend to be both complex and multifaceted to their nature.

Studies on design, fabrication and reliability assessment of embedded passives on a high-density interconnect (HDI) organic substrate using a sequential build-up process

One of the foremost design considerations in microelectronics miniaturization is the use of embedded passives which provide practical solution. In a typical circuit, over 80 percent of the electronic components are passives such as resistors, inductors, and capacitors that could take up to almost 50 percent of the entire printed circuit board area. By integrating passive components within the substrate instead of being on the surface, embedded passives reduce the system real estate, eliminate the need for discrete and assembly, enhance electrical performance and reliability, and potentially reduce the overall cost. Moreover, it is lead free. Even with these advantages, embedded passive technology is at a relatively immature stage and more characterization and optimization are needed for practical applications leading to its commercialization.This paper presents an entire process from design and fabrication to electrical characterization and reliability test of embedded passives on multilayered microvia organic substrate. Two test vehicles focusing on resistors and capacitors have been designed and fabricated. Embedded capacitors in this study are made with polymer/ceramic nanocomposite (BaTiO3) material to take advantage of low processing temperature of polymers and relatively high dielectric constant of ceramics and the values of these capacitors range from 50 pF to 1.5 nF with capacitance per area of approximately 1.5 nF/cm(2). Limited high frequency measurement of these capacitors was performed. Furthermore, reliability assessments of thermal shock and temperature humidity tests based on JEDEC standards were carried out. Resistors used in this work have been of three types: 1) carbon ink based polymer thick film (PTF), 2) resistor foils with known sheet resistivities which are laminated to printed wiring board (PWB) during a sequential build-up (SBU) process and 3) thin-film resistor plating by electroless method. Realization of embedded resistors on conventional board-level high-loss epoxy (similar to 0.015 at 1 GHz) and proposed low-loss BCB dielectric (similar to 0.0008 at > 40 GHz) has been explored in this study. Ni-P and Ni-W-P alloys were plated using conventional electroless plating, and NiCr and NiCrAlSi foils were used for the foil transfer process. For the first time, Benzocyclobutene (BCB) has been proposed as a board level dielectric for advanced System-on-Package (SOP) module primarily due to its attractive low-loss (for RF application) and thin film (for high density wiring) properties.Although embedded passives are more reliable by eliminating solder joint interconnects, they also introduce other concerns such as cracks, delamination and component instability. More layers may be needed to accommodate the embedded passives, and various materials within the substrate may cause significant thermo -mechanical stress due to coefficient of thermal expansion (CTE) mismatch. In this work, numerical models of embedded capacitors have been developed to qualitatively examine the effects of process conditions and electrical performance due to thermo-mechanical deformations.Also, a prototype working product with the board level design including features of embedded resistors and capacitors are underway. Preliminary results of these are presented.

Design options reduce exchanger cost

Heat exchanger design is a complex task involving the selection of a large number of interdependent design parameters. There are no established general techniques for optimizing the design, though a few earlier attempts provide computer software based on gradient methods, case study methods, etc. The authors felt that it would be useful to determine the nature of the optimal and near-optimal feasible designs to devise an optimization technique. Therefore, in this article they have obtained a large number of feasible designs of shell and tube heat exchangers, intended to perform a given heat duty, by an exhaustive search method. They have studied how their capital and operating costs varied. The study reveals several interesting aspects of the dependence of capital and total costs on various design parameters. The authors considered a typical shell and tube heat exchanger used in an oil refinery. Its heat duty, inlet temperature and other details are given.

The chemistry of a non-natural product: Troger's base

Troger's base was the first amine to be resolved where the chirality was solely due to very high inversion barrier around nitrogen atom(s). Though the molecule was known over a century, work done during the past one decade has shown that Troger's base and its analogues could be used as chiral solvating agents, DNA-binding ligands and for the construction of biomimetic molecular receptors and clathrate hosts, Asymmetric synthesis of Troger's base analogues has also been achieved recently, Because of the rigid, 'V'-shaped chiral nature of this molecule, there is a growing interest for use of this unit in the design of potential host systems, This review article focuses on the chemistry of Troger's base along with the possible future utilities.

A low power, process invariant keeper design for high speed dynamic logic circuits

A low power keeper circuit using the concept of rate sensing has been proposed. The proposed technique reduces the amount of short circuit power dissipation in the domino gate by 70% compared to the conventional keeper technique. Also the total power-delay product is 26% lower compared to the previously reported techniques. The process tracking capability of the design enables the domino gate to achieve uniform delay across different process corners. This reduces the amount of short circuit power dissipation that occurs in the cascaded domino gates by 90%. The use of the proposed technique in the read path of a register file reduces the energy requirement by 26% as compared to the other keeper techniques. The proposed technique has been prototyped in 130nm CMOS technology.

Coordination-driven self-assembly of 2D-metallamacrocycles using a shape-selective Pt(2)(II)-organometallic 90 degrees acceptor: design, synthesis and sensing study

Synthesis of a series of two-dimensional metallamacrocycles via coordination-driven self-assembly of a shape-selective Pt(2)(II)-molecular building unit incorporating carbazole-ethynyl functionality is described. An equimolar (1 : 1) combination of a Pt(2)(II)-organometallic 90 degrees acceptor, 1, with rigid linear ditopic donors (L(a) and L(b)) afforded [4 + 4] self-assembled octanuclear molecular squares, 2 and 3, in quantitative yields, respectively [L(a) = 4,4'-bipyridine; L(b) = trans-1,2-bis(4-pyridyl)ethylene]. Conversely, a similar treatment of 1 with an amide-based unsymmetrical flexible ditopic donor, L(c), resulted in the formation of a [2 + 2] self-sorted molecular rhomboid (4a) as a single product [L(c) = N-(4-pyridyl)isonicotinamide]. Despite the possibility of several linkage isomeric macrocycles (rhomboid, triangle and square) due to the different connectivity of L(c), the formation of a single and symmetrical molecular rhomboid (4a) as the only product is an interesting observation. All the self-assembled macrocycles (2, 3 and 4a) were fully characterized by multinuclear NMR ((1)H and (31)P) and ESI-MS analysis. Further structural insights about the size and shape of the macrocycles were obtained through energy minimization using density functional theory (DFT) calculations. Decoration of the starting carbazole building unit with Pt-ethynyl functionality enriches the assemblies to be more p-electron rich and luminescent in nature. Macrocycles 2 and 3 could sense the presence of electron deficient nitroaromatics in solution by quenching of the initial intensity upon gradual addition of picric acid (PA). They exhibited the largest quenching response with high selectivity for nitroaromatics compared to several other electron deficient aromatics tested.

Optimal design of timer-based, distributed selection with unknown number of nodes

The timer-based selection scheme is a popular, simple, and distributed scheme that is used to select the best node from a set of available nodes. In it, each node sets a timer as a function of a local preference number called a metric, and transmits a packet when its timer expires. The scheme ensures that the timer of the best node, which has the highest metric, expires first. However, it fails to select the best node if another node transmits a packet within Delta s of the transmission by the best node. We derive the optimal timer mapping that maximizes the average success probability for the practical scenario in which the number of nodes in the system is unknown but only its probability distribution is known. We show that it has a special discrete structure, and present a recursive characterization to determine it. We benchmark its performance with ad hoc approaches proposed in the literature, and show that it delivers significant gains. New insights about the optimality of some ad hoc approaches are also developed.

Design and construction of geocell foundation to support the embankment on settled red mud

This paper presents the case history of the construction of a 3 m high embankment on the geocell foundation over the soft settled red mud. Red mud is a waste product from the Bayer process of Aluminum industry. Geotechnical problems of the site, the design of the geocell foundation based on experimental investigation and the construction sequences of the geocell foundations in the field are discussed in the paper. Based on the experimental studies, an analytical model was also developed to estimate the load carrying capacity of the soft clay bed reinforced with geocell and combination of geocell and geogrid. The results of the experimental and analytical studies revealed that the use of combination of geocell and the geogrid is always beneficial than using the geocell alone. Hence, the combination of geocell and geogrid was recommended to stabilize the embankment base. The reported embankment is located in Lanjigharh (Orissa) in India. Construction of the embankment on the geocell foundation has already been completed. The constructed embankmenthas already sustained two monsoon rains without any cracks and seepage. (C) 2013 Elsevier Ltd. All rights reserved.

Comprehending the Formation of Eutectics and Cocrystals in Terms of Design and Their Structural Interrelationships

The phenomenon of cocrystallization, which encompasses the art of making multicomponent organic solids such as cocrystals, solid solutions, eutectics, etc. for novel applications, has been less studied in terms of reliably and specifically obtaining a desired cocrystallization product and the issues that govern their formation. Further, the design, structural, and functional aspects of organic eutectics have been relatively unexplored as compared to solid solutions and cocrystals well-established by crystal engineering principles. Recently, eutectics were proposed to be designable materials on par with cocrystals, and herein we have devised a systematic approach, based on the same crystal engineering principles, to specifically and desirably make both eutectics and cocrystals for a given system. The propensity for strong homomolecular synthons over weak heteromolecular synthons and vice versa during supramolecular growth was successfully utilized to selectively obtain eutectics and cocrystals, respectively, in two model systems and in two drug systems. A molecular level understanding of the formation of eutectics and cocrystals and their structural interrelationships which is significant from both fundamental and application viewpoints is discussed. On the other hand, the obscurity in establishing a low melting combination as a eutectic or a cocrystal is resolved through phase diagrams.

A Modified Sum-Product Algorithm over Graphs with Isolated Short Cycles

We investigate into the limitations of the sum-product algorithm in the probability domain over graphs with isolated short cycles. By considering the statistical dependency of messages passed in a cycle of length 4, we modify the update equations for the beliefs at the variable and check nodes. We highlight an approximate log domain algebra for the modified variable node update to ensure numerical stability. At higher signal-to-noise ratios (SNR), the performance of decoding over graphs with isolated short cycles using the modified algorithm is improved compared to the original message passing algorithm (MPA).