Perspectives on Design and Innovation

A series of studies of top European and other firms has revealed patterns of design management associated with commercial success. Firms that invest resources and professional expertise in product and industrial design in traditional and new industries have been commercially more successful than firms that pay less attention to these aspects of design. As an industry matures there is a shift in emphasis from design associated with technological innovation, to designs supporting technical improvements, and then to supporting user needs, fashion and product variants. These issues are illustrated through the history of the evolution of the bicycle.     

Mathematical and experimental method to obtain the inverse modeling of nonsinusoidal and saturated synchronous reluctance motors

This paper presents new inverse modeling for synchronous reluctance motor (SyRM). This modeling is valid when the inductances are sinusoidal or nonsinusoidal and even when the machine is saturated. This technique involves the generation of constant torque curves as a function of two-phase currents in the Concordia's reference frame when the rotor angle is fixed. We also introduce an experimental method to obtain directly the inverse modeling. This practical method takes into account the saturation of the motor. This technique allows the reduction of the low torque ripple in the case of nonsinusoidal inductances.     

Process-based cost modeling of photonics manufacture: the cost competitiveness of monolithic integration of a 1550-nm DFB laser and an electroabsorptive modulator on an InP platform

The monolithic integration of components holds promise to increase network functionality and reduce packaging expense. Integration also drives down yield due to manufacturing complexity and the compounding of failures across devices. Consensus is lacking on the economically preferred extent of integration. Previous studies on the cost feasibility of integration have used high-level estimation methods. This study instead focuses on accurate-to-industry detail, basing a process-based cost model of device manufacture on data collected from 20 firms across the optoelectronics supply chain. The model presented allows for the definition of process organization, including testing, as well as processing conditions, operational characteristics, and level of automation at each step. This study focuses on the cost implications of integration of a 1550-nm DFB laser with an electroabsorptive modulator on an InP platform. Results show the monolithically integrated design to be more cost competitive over discrete component options regardless of production scale. Dominant cost drivers are packaging, testing, and assembly. Leveraging the technical detail underlying model projections, component alignment, bonding, and metal-organic chemical vapor deposition (MOCVD) are identified as processes where technical improvements are most critical to lowering costs. Such results should encourage exploration of the cost advantages of further integration and focus cost-driven technology development.     

Prebiotic synthesis of sequential peptides on the Hadean beach by a molecular engine working with nitrogen oxides as energy sources

Addressing the still open question of the prebiotic origin of sequential macromolecules (peptides, nucleic acids) on the primitive Earth, we describe a molecular engine (the primary pump), which works at ambient temperature and continuously generates, elongates and complexifies sequential peptides. This new scenario is based on a cyclic reaction sequence, whose keystep is the activation of amino acids into their N‐carboxyanhydrides (NCA) through nitrosation by NOx. This process could have taken place on tidal beaches; it requires a buffered ocean, emerged land and a nitrosating atmosphere. With the help of geochemical studies and computer simulations of atmosphere photochemistry, we show that the primitive Earth during the Hadean may have satisfied all these requirements. © 2001 Society of Chemical Industry.     

Valorisation of mango seed via extraction of starch: preliminary techno-economic analysis

Reducing environmental impacts and obtaining economic benefits based on utilisation of waste materials are drivers for the implementation of cleaner production policies and technologies in food processing industries. Starch is a very versatile material with a wide range of applications in the food, pharmaceutical, textile, paper, cosmetic and construction industries. In Ethiopia, starch is widely used in the textile industry. To meet the starch demand, the country imports approximately 45% of the starch used in the country. Consequently, it is imperative to find additional sources of starch that could substitute for the amount of starch that is currently being imported. Mango seeds, a waste material that is disposed of after consumption of mangos, were studied for potential use as an alternative resource for starch production. The results showed that starch extraction from mango seeds was facile and a good quality product was obtained. The present study is concerned with a techno-economic analysis for industrial production of starch from mango seeds. The study shows that extraction of starch from waste mango seeds is feasible: the project is financially viable with an accounting rate of return of 83% and a break-even analysis of 78% with a payback period of 2 years.     

Cortical hierarchies, sleep, and the extraction of knowledge from memory

Odin the Allfather had in his service two great ravens. These ravens' names were Hugin (Thought) and Munin (Memory) and every morning at dawn they would fly off over Midgard (the world) in search of news and information to learn more about humans and their activities. At sundown, they would return to Odin where they would perch one on each of Odin's shoulders, and whisper into his ears all that they had seen and heard.Experience, stored in the brain as memory, is the raw material for intelligence and thought. It has been suggested that at sundown (i.e., during sleep) the brain adjusts its own synaptic matrix to enable adaptive responses to future events by a process of gradient descent optimization, involving repeated reactivations of recent and older memories and gradual adjustment of the synaptic weights. Memory retrieval, thought, and the generation of adaptive behavioral responses involve globally coordinated trajectories through the neuronal state-space, mediated by appropriate synaptic linkages. Artificial neural networks designed to implement even the most rudimentary forms of memory and knowledge extraction and adaptive behavior incorporate massively and symmetrically interconnected nodes; yet, in the cerebral cortex, the probability of a synaptic connection between any two arbitrarily chosen cells is on the order of 10⁻⁶, i.e., so close to zero that a naive modeler might neglect this parameter altogether. The probability of a symmetric connection is even smaller (10⁻¹²). How then, are thought and memory even possible? The solution appears to have been in the evolution of a modular, hierarchical cortical architecture, in which the modules are internally highly connected but only weakly interconnected with other modules. Appropriate inter-modular linkages are mediated indirectly via common linkages with higher level modules collectively known as association cortex. The hippocampal formation in the temporal lobe is the highest level of association cortex. It generates sequentially coupled patterns unique to the location and content of experience, but which do not contain the actual stored data. Rather, the patterns serve as pointers or ‘links’ to the data. Spontaneous reactivation of these linking patterns during sleep may enable the retrieval of recent sequences of experience stored in the lower levels of the cortex and the gradual extraction of knowledge from them. In this essay I explore these ideas, their implications, and the neuroscientific evidence for them.     

Superfluid3He-B in a realistic thin film. Gap and critical current

We examine³He-B confined to a thin film on a rough substrate with a freestanding upper surface by using quasiclassical techniques. First, the dependence of the gap on surface roughness, film width, and boundary condition formulation is examined in detail for the current-free state. The evaluation is conducted using both the Randomly Rippled Wall and the Thin Dirty Layer surface models in order to compare them. Second, the current bearing state for a submicron film resting on a rough substrate is calculated using the Thin Dirty Layer surface model. Several unusual and previously unreported features appear in both cases. Numerical estimates of the critical current densities are in favorable agreement with corresponding experiments.