Design Recipe Research Articles

On the Safety Hierarchy and Hierarchy of Controls

History reveals an ever-increasing caboodle of protective measures for assuring an acceptable level of safety for both new product designs and for the remediation of man-made and natural hazards. Some seventy years ago, safety professionals began to functionally categorize these safety tools and rank the categories according to their perceived effectiveness. At first, the resulting hierarchies were designated Safety Hierarchies; later updated versions are now referred to as Hierarchies of Controls. To characterize Hierarchies, sixty-six references were surveyed that were published after 1952. Each of these design recipes begin with the admonition “Eliminate the hazards.” All of the hierarchies were created using consensus or speculation, not research. We establish that the Safety Hierarchies and the Hierarchies of Controls are merely rules of thumb, not theorems. Generally, different hierarchies give rise to different designs. The principal strength of both Hierarchies is their replacement of the myth of colloquial safety as “freedom from harm” with a realistic technical definition of safety as an “acceptable level of risk” that is systematically achievable however tortuous.

Message Design Recipes Inducing Sharing-Service Customer’s Intention of Performing a Given Role: Using Fuzzy-Set Qualitative Comparative Analysis

Message Design Recipes Inducing Sharing-Service Customer’s Intention of Performing a Given Role: Using Fuzzy-Set Qualitative Comparative Analysis

Wave-Function Engineering for Spectrally Uncorrelated Biphotons in the Telecommunication Band Based on a Machine-Learning Framework

Indistinguishable single photons are key ingredient for a plethora of quantum information processing applications ranging from quantum communications to photonic quantum computing. A mainstream platform to produce indistinguishable single photons over a wide spectral range is based on biphoton generation through spontaneous parametric down-conversion (SPDC) in nonlinear crystals. The purity of the SPDC biphotons, however, is limited by their spectral correlations. Here, we present a design recipe, based on a machine-learning framework, for the engineering of biphoton joint spectrum amplitudes over a wide spectral range. By customizing the poling profile of the KTiOPO$_4$ (KTP) crystal, we show, numerically, that spectral purities of 99.22%, 99.99%, and 99.82% can be achieved, respectively, in the 1310-nm, 1550-nm, and 1600-nm bands after applying a moderate 8-nm filter. The machine-learning framework thus enables the generation of near-indistinguishable single photons over the entire telecommunication band without resorting to KTP crystal's group-velocity-matching wavelength window near 1582 nm.

Hierarchically tailorable double-array film hybrids with enhanced photocatalytic and photoelectrochemical performances

The basic mantra of “structure-dictates-function” in chemistry has inspired tremendous interests in designing various architectures toward specific applications. In this work, hierarchically tailorable double-array structures composed of TiO2 nanotube arrays (TNTAs) and axially grown ZnO nanorod arrays (ZNRAs) have been constructed through a two-step anodization method combined with a heteroepitaxial growth process regulated by electrodeposited reduced graphene oxide (RGO). The obtained TNTAs/RGO/ZNRAs film hybrids exhibit enhanced photocatalytic and photoelectrochemical performances along with favorable photostability as compared to the single component and binary counterparts. This is ascribed to the synergistic effect of the matchable band alignment of the components, the 1D-on-1D double-array architecture with vectorial pathways for charge carriers transport, and the electrically conductive RGO for bridging the directional electron flow to further promote the separation and transfer of charge carriers. This work is anticipated to provide instructive recipe for rational design and construction of composite films with optimized photo(electro)catalytic performances.

The effect of soaking time after ultrafast heating on the microstructure and mechanical behavior of a low carbon steel

The main objective of this study is to understand the effect of the soaking time during the ultrafast heat treatment of a low carbon steel on its complex multi-phase microstructure, tensile mechanical behavior and properties of individual microconstituents. Tensile tests were performed to determine the macro-mechanical properties. Nanoindentation testing was carried out on individual microconstituents (martensite, recrystallized ferrite and non-recrystallized ferrite) identified a priori via EBSD analysis to measure their properties. It is shown that ultrafast heating combined with short soaking times results in improved macro-mechanical properties due to finer grain size and higher fraction of non-recrystallized ferrite, that has a higher nanohardness than recrystallized ferrite. Prolonged soaking times eliminate the advantages of the ultrafast heat treatment. This occurs because, even though a long soaking time promotes a higher volume fraction of martensite than a short one, it also induces substantial grain growth and complete recrystallization of the ferritic matrix. On the micro-scale, the ferritic grains show two different types of mechanical response. The recrystallized ferritic grains are prone to show pop-in events on the nanoindentation curves that are associated to dislocation nucleation events as a consequence of their low dislocation density, while non-recrystallized ferritic grains demonstrate a continuous response. The relationship between microstructure and mechanical properties on the macro- and micro-scales is discussed with respect to the microstructure, which in turn strongly depends on the applied heating rate and soaking time. A general recipe for microstructural design to improve the tensile mechanical behavior of low carbon steels implementing controlled heating and soaking conditions is outlined.

On the SPRification of Linear Descriptor Systems via Output Feedback

We consider input–output systems in descriptor form and ask when such systems can be rendered strictly positive real (SPR) via output feedback. Time- and frequency-domain conditions are given to determine when and how this is possible. In addition, a synthesis procedure for controller design is also derived. Together, the results provide a complete answer to when a linear descriptor system can be made SPR via output feedback, and provide a recipe for design of a feedback controller when one exists.

Tuneable Metamaterial-like Platforms for Surface-Enhanced Raman Scattering via Three-Dimensional Block Co-polymer-Based Nanoarchitectures.

Surface-enhanced Raman spectroscopy (SERS) pushes past the boundaries and inherent weaknesses of Raman spectroscopy, with a great potential for a broad range of applications particularly, for sensing. Yet, current real world applications are limited due to poor reproducibility, low-throughput, and stability issues. Here, we present the design and fabrication of self-assembly guided structures based on adjustable block co-polymer (BCP) nanomorphologies and demonstrate reproducible SERS enhancement across large areas. Golden three-dimensional (3D) nanostructured morphologies with controllable dimensions and morphologies exhibit high chemical stability, enhanced plasmonic properties and are highly suitable for SERS substrates due to the strong enhancement of the electromagnetic field. Adjustable, free standing porous nanostructures, continuous in 3D space are achieved by removal of selected BCP constituents. Four BCP morphologies and the corresponding achievable enhancement factors are investigated at 633 and 785 nm excitation wavelengths. The choice of excitation laser is shown to greatly affect the observed signal enhancement, highlighting the sensitivity of the technique to the underlying surface architecture and length scales. By using BCP assemblies, it is possible to reliably tune these parameters to match specific applications, thus bridging the gap toward the realization of applied metamaterials. The fabricated SERS platforms via three-dimensional block co-polymer-based nanoarchitectures provide a recipe for intelligent engineering and design of optimized SERS-active substrates for utilization in the Raman spectroscopy-based devices toward enabling the next-generation technologies fulfilling a multitude of criteria.

Cement Concrete Mixture Performance Characterization

The cementitious composite nature of concrete makes very diffi cult directly ascertaining each mixture-factors’ contribution to a given concrete mixture performance characteristics but also doubly diffi cult to accurately balance mutually exclusive requirements for performance (workability, strength, durability) and sustainability (the economic and effi cient use of materials) for mixture proportioning based on recipes of previously produced concretes. This study sought to quantify individual mixture-factors’ contribution to a given concrete mixture’s performance characteristics. Proposed multi-parametric exponential mixture-response models were fi tted to available test-performance data sets of HPC mixtures proportioned based on the best combined grade aggregate (minimum void) to generate mixture-strength and mixture-porosity development (age-mixture response relationships) profi les of HPC mixtures and deemed robust enough to yield reliable determination of mixture-response rate-parameters So, Sp, Si and Po, Pp, Pi as functions of mixture-factors that permitted reliable quantifi cation of contributions to HPC mixture performance of individual mixture-factors and optimization of mixture properties under study over the study domain. Mixture-response sensitivity analysis models (or mixture response trace plots) to allow construction of mixture-factor envelopes and ultimately optimized mixture-response models to facilitate selection of optimal mixture-factors and optimal tailoring of HPC mixture requirements to HPC mixture performance were developed and used to obtain optimized adapted HPC mixtures from available high performance concrete (HPC) mixture design recipes investigated in the study over the study domain. Adapted HPC mixture design recipes yielded alternative mixture compositions with improved performance and effi ciency characteristics with statistical performance metrics MAPE, NMBE and RMSE values of 7.6%,–3.7% and 6.5 MPa, respectively.

Influence of dilute solute substitutions in Ni on its generalized stacking fault energies and ductility

We determine effects of substitutional solutes belonging to 3d, 4d and 5d transition metal (TM) series on volume, intrinsic stacking fault energy (ISFE), unstable stacking fault energy (USFE) and ductility parameter of Ni using first-principles calculations based density functional theory (DFT), considering both ferromagnetic (spin-polarized) and non-magnetic states of Ni. For each of the TM series, we find that volume exhibits a minimum for substitutional elements with half-filled d-orbitals (5 d-electrons). Reduction in ISFE of Ni is seen with all the solute additions except for Pd (in the non-magnetic case). Inclusion of spin-polarization has a pronounced effect on the fault energies and results in increase in both ISFE as well as USFE. In the non-magnetic case, USFE exhibits maxima for alloying with elements having five electrons in d-orbital. Except for Zr and Pd, substitution of other elements enhanced cleavage energy of Ni. Differences in the fault energies on alloying have been explained based on the electronic structure of the alloys. There exists a correlation between change in volume and change in USFE with substitutional alloying. It is envisaged that the exhaustive data generated here would not only form necessary input to multi-scale microstructural modeling, but also help in evolving simple recipes for design of new alloys.

Trapping Light in Plain Sight: Embedded Photonic Eigenstates in Zero‐Index Metamaterials

AbstractConfining electromagnetic energy is crucial to enhance light‐matter interactions, with important implications for science and technology. Here, the opportunities offered by trapping and confining light in open structures, based on the concept of embedded eigenstates within the radiation continuum enabled by zero‐index metamaterials, are discussed. Building upon the physical insights offered by the analysis, a general platform is put forward that allows the realization of extremely high field enhancements in open structures under external illumination. Structures supporting embedded eigenstates represent a rare example of physical systems in which extreme–in principle unbounded–responses can be tamed. The proposed design recipe to realize bound states in the continuum also offers a simple model that allows testing of important questions that surround the concept of embedded eigenstates, such as their effect on the local density of photonic states. The findings help clarify which nano‐optical and radio‐wave applications may benefit from this unusual and singular response.

Design Methodologies of Compact Orthomode Transducers Based on Mechanism of Polarization Selectivity

An orthomode transducer (OMT) design is presented and implemented for future RF and millimeter-wave applications. The novelty of the proposed OMT stems from a distinct concept of handling dual-polarized signals on the basis of a polarization-selective coupler (PSC). The theory of the PSC is developed and understood through analyzing its constituent waveguides. Such waveguides are hybrid forms of nonradiative dielectric waveguide and substrate-integrated waveguide. An equivalent circuit model is deduced for modeling dispersion characteristics of the PSC. Consequently, design methodologies supported with comprehensive theoretical study and simulation analysis for a PSC-based OMT are developed and examined. The general design of a PSC-based OMT basically depends on a dielectric slab coupler waveguide with a longitudinal periodic PEC polarizer wall in its middle. Practical limitations for this design is discussed and supported with solutions using a proposed top slot coupler instead of the dielectric slab coupler. Closed-form equations are obtained as design recipes for computing structure dimensions and bandwidth based on operating frequency and the material parameters. The proposed structure is prototyped and measured. Measured results show an acceptable agreement with simulation results.

Freeform lens design to eliminate retroreflection for optical systems.

This paper presents an effective approach to alleviate the cat-eye effect by inserting a freeform single lens into the original optical system. By shifting the image of the given optical system transversely on the original image plane, the reflected beams originating from the sensor are subsequently blocked by the optical aperture, substantially eliminating retroreflections from the system. The influence of incident angle on retroreflected beams is analyzed in detail, and the optimal image translation distance for completely eliminating the cat-eye effect is also proposed via numerical simulations. According to the translation requirement, a freeform single lens comprised of two different freeform surfaces is designed for the given system as the only translation element. The design recipe is elaborated on the basis of phase pupil function. Furthermore, a design example is demonstrated to verify the feasibility of our proposal. After optimization with optical design software, the modulation transfer function (MTF) of the modified system after translation is close to the diffraction limit, and the cat-eye reflected beam could be eliminated thoroughly.

Infusing an HtDP-based CS1 with distributed programming using functional video games

AbstractA Computer Science introduction course ought to focus on exciting students about the subject matter and on problem solving through the methodical design of programs. An effective way to achieve both is through the development of functional video games. As most students are interested in video games, their development adds an exciting domain to any introduction to programming. This article advocates that an exciting crowning achievement for students in such a course is the design and implementation of a multiplayer distributed video game. By exploiting a domain that is popular with students, they are taught about design principles, communication protocols, and pitfalls in distributed programming. This article puts forth a successfully used design recipe that places distributed programming well within the reach of beginning students and outlines the use of this design recipe in the classroom. For those teaching beginners, this article presents a model for developing their own distributed programming module. The success of the presented methodology is measured through student feedback on their distributed programming experience. The empirical results suggest that the design and implementation of distributed functional video games is effective and well-received by students. Furthermore, the data suggests that the presented methodology fails to exhibit the gender gap common in Computer Science and is effective regardless of the programming experience CS1 students bring to the classroom.

Ultracompact graphene-assisted ring resonator optical router

Optical routers with compact footprint and low energy consumption are of high demand for optoelectronic integrations. We demonstrate a graphene-assisted optical router based upon silicon ring resonator configurations. The electrical tunability and the influence that graphene has upon the effective mode index are investigated, from monolayer to multiple graphene layers. The corresponding waveguide structure design is further discussed and optimized via numerical simulations. Meanwhile, the design recipes are also discussed and our proposal possesses broad free spectrum range reaching 3.64 THz, lenis crosstalk below −15 dB, low loss and low power consumption that is propitious to versatile wavelength division multiplexing systems and on-chip silicon optical interconnects.

Optimal V-Reflector Design With Maximum Solar Concentration

For low-concentration solar applications, v-reflectors are attractive choice to collect sunlight since they are simple to build with reduced manufacturing cost and technical requirements. In this paper, with the account for the power evolution of all possible reflection modes, careful modeling for the concentration ratio of such collectors was achieved and optimized by numerical methods in order to determine the optimal apex-angle that facilitates maximum utilization of the solar energy. The outcome of this research is interesting since it provides a useful recipe for an optimal design of v-reflectors that can be found in various solar applications.

Transformation optics for surface phenomena: Engineering the Goos-Hänchen effect

Transformation optics, a geometrical recipe for metamaterial design, was originally conceived as a tool to smoothly modify the trajectory of light using continuous coordinate transformations. Here, we show how discontinuous transformations can be used as a geometric framework to understand and manipulate phenomena at the surface of nanophotonic structures. In particular, we show how the Goos-Hanchen shift - a lateral shift exhibited by totally reflected beams - can be tailored and we provide a classification and complete analytical description of this effect in existing complex media.

Response-based analysis for Tension Leg Platform

The typical industry practice for Tension Leg Platform (TLP) design focuses on a conventional short-term design recipe, which assumes that an N-year design environment leads to an N-year response. In the response-based design method, the TLP is designed to withstand N-year responses rather than respond to N-year environmental conditions. In this paper, we present an overview and a general procedure for the response-based design method and use a case study to compare the critical TLP responses between the two methods. The results of our comparison show that the conventional short-term design method often contains an element of conservatism and that the response-based design method can reduce the design conditions and thereby achieve cost savings.

Optimal sound-absorbing structures

Absorption by design, with minimal sample thickness allowed by the law of nature, can now be realized by using a design recipe that incorporates the causal constraint of acoustic response as a crucial element.

The End of Design Theory

By the advent of the Bauhaus, the notion of design did engage in a two-track operation. Without dissociating itself from themes central to the formation of the architectural discipline, the concept of design, on the one hand, had to recode and at times delete thematic that had attained visibility in the context of labour and skills that were not sustainable under the rising regime of mechanical reproducibility. On the other hand, design became interactive in a web of communication and consumption systems that were informed by the exigencies of a culture that in less than fifty years would be coined the culture-industry. The nemesis of design in contemporary situation marked by the globalization of capital and information, I will argue, demands a radical departure from design recipes, past and present, that do not engage critically with the present production and consumption conditions of architecture. Discussing the collective implicitly involved in tectonics, this paper highlights the paradox in the contemporary theorization of design. This involves a different praxis, one that would surpass the prevailing rapport between academia (history/theory) and profession (practice).

Testing a recipe for effective recovery plan design: a marine turtle case study

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 31:147-161 (2016) - DOI: https://doi.org/10.3354/esr00755 Testing a recipe for effective recovery plan design: a marine turtle case study Jasmine D. Roberts, Mark Hamann* College of Marine and Environmental Sciences, James Cook University, Townsville QLD 4811, Australia *Corresponding author: mark.hamann@jcu.edu.au ABSTRACT: Managing impacts to threatened species is challenging, because it is intrinsically linked to resources, knowledge, capacity and public and government will. A key tool often used in species conservation is a recovery or management plan. Yet all too often, plans are not designed for evaluation and not tested against quantitative criteria. Our study takes a novel approach to recovery plan assessment by assembling a worldwide database of recovery plans for a single taxon. We obtained 79 recovery or management plans for marine turtles and then designed criteria to assess and compare them for their ability to be evaluated and thus successfully implemented. We then used expert opinion of marine turtle specialists to weigh our 18 criteria. Overall, we found that the failure to adequately integrate adaptive management into plan design was a major shortcoming of marine turtle recovery planning (>90% of plans). Other common gaps included inadequacy of measurable objectives (75% of plans) and an absence of timelines (50% of plans). We highlight knowledge gaps relating to status trends, critical habitat and a lack of incorporation of social aspects such as stewardship and education. Our research underlines the importance of recovery planning from multiple scales and provides a step towards designing recovery plans that include SMART (specific, measurable, achievable, realistic and time-bound) objectives; scientific information; social aspects; and evaluation. We highlight the importance of national and multi-national planning processes to produce internationally relevant plans that will maximise conservation efforts for a globally threatened marine species. KEY WORDS: Marine turtles · Recovery planning · Threatened species · SMART Full text in pdf format PreviousNextCite this article as: Roberts JD, Hamann M (2016) Testing a recipe for effective recovery plan design: a marine turtle case study. Endang Species Res 31:147-161. https://doi.org/10.3354/esr00755 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 31. Online publication date: October 13, 2016 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2016 Inter-Research.