Technical University Of Denmark Research Articles

Direct fabrication of bio-inspired gecko-like geometries with vat polymerization additive manufacturing method

Functional surfaces have proven their potential to solve many engineering problems, attracting great interest among the scientific community. Bio-inspired multi-hierarchical micro-structures grant the surfaces with new properties, such as hydrophobicity, adhesion, unique optical properties and so on. The geometry and fabrication of these surfaces are still under research. In this study, the feasibility of using direct fabrication of microscale features by additive manufacturing (AM) processes was investigated. The investigation was carried out using a specifically designed vat photopolymerization AM machine-tool suitable for precision manufacturing at the micro dimensional scale which has previously been developed, built and validated at the Technical University of Denmark. It was shown that it was possible to replicate a simplified surface inspired by the Tokay gecko, the geometry was previously designed and replicated by a complex multi-step micromanufacturing method extracted from the literature and used as benchmark. Ultimately, the smallest printed features were analyzed by conducting a sensitivity analysis to obtain the righteous parameters in terms of layer thickness and exposure time. Moreover, two more intricate designs were fabricated with the same parameters to assess the surfaces functionality by its wettability. The surface with increased density and decreased feature size showed a water contact angle (CA) of 124° ± 0.10°, agreeing with the Cassie–Baxter model. These results indicate the possibility of using precision AM for a rapid, easy and reliable fabrication method for functional surfaces.

Genome‐scale reconstructions of the mammalian secretory pathway predict metabolic costs and limitations of protein synthesis and secretion

In mammals, >25% of proteins are synthesized and exported through the secretory pathway. The pathway complexity, however, obfuscates its impacts on the secretion of different proteins. Here we have mapped out the core biosynthetic proteins of the secretory pathway and integrate them with genome-scale metabolic models of human, mouse, and Chinese hamster ovary (CHO) cells. The resulting reconstructions RECON2.2s, iMM1685s, and iCHO2048s, enable the computation of the cost and machinery demanded by each secreted protein. We predicted metabolic costs and maximum productivities of biotherapeutics, and identified protein features that most significantly impact protein secretion. By integrating additional metabolomic, glycoproteomic and ribosomal profiling data, we further found that CHO cells have adapted to reduce expression and secretion of expensive host cell proteins. Finally, we are able to quantify improvements in protein production in CHO cells following efforts to eliminate unnecessary proteins. Our work represents a knowledge-base of the mammalian secretory pathway that serves as a novel tool for systems biotechnology. Support or Funding Information The Novo Nordisk Foundation through the Center for Biosustainability at the Technical University of Denmark (NNF10CC1016517 and NNF16CC0021858) and from the NIGMS (R35 GM119850) The core biosynthetic pathways of the mammalian secretory pathway have been mapped out and enable quantitative analysis using systems biology models. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Can we capture an accurate view of tissue metabolism from an expression profile?

Genome-scale models of metabolism have been constructed with the aim of illuminating the molecular basis of cell phenotypes. Since some enzymes are only active in specific cell or tissue types, several algorithms use various omics data types (e.g., transcriptomics, proteomics, metabolomics, genomic variant calls) to construct cell line and tissue-specific metabolic models from genome-scale models. However, it is unclear how algorithm and parameter selection (e.g., gene expression thresholds, metabolic constraints) affects model content and predictive accuracy. To investigate this, we built hundreds of models of four different cancer cell lines using transcriptomics, metabolomics, various algorithms and different parameter sets. Model content varied substantially across different parameter sets, but all algorithms generally increased accuracy in identifying cancer cell vulnerabilities. However, the choice of algorithm had the largest impact on model accuracy. Finally, we further developed a framework to predict, de novo, the metabolic capabilities of a cell or tissue, based on its gene expression and metabolomic profiles. These insights will guide further development of tissue and cell type specific models, and enable us to predict phenotype from genotype. Support or Funding Information The Novo Nordisk Foundation through the Center for Biosustainability at the Technical University of Denmark (NNF10CC1016517 and NNF16CC0021858) and from the NIGMS (R35 GM119850). Tissue specific metabolic models can be constructed using various omics data, but careful decisions on algorithms and parameter choice are necessary to predict a tissue's metabolic functions de novo. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Exploring the chemistry of complex samples by tentative identification and semiquantification: A food contact material case

In this month's Featured Article Eelco Pieke and his colleagues from the National Food Institute, Technical University of Denmark, discuss some timely issues in the objective and practical assessment of food and environmental safety. As the authors rightly suggest, in our increasingly unpredictable world, even with powerful analytical tools at our disposal, the realistic assessment of risk is a challenge. In any given scenario, an almost limitless array of unknown substances can ‘contaminate’ our environment, and depending on structure, properties and amount, any one of these could pose a significant threat. The task of defining the risk in a cost- and time-efficient manner is much more than an exercise in analytical chemistry given the volume of data, scope of the problem and the uncertainties involved. In this article Pieke, Smedsgaard and Granby discuss their approach to defining and prioritizing risk. They use mass spectrometry as their central analytical platform for both structural elucidation and to estimate analyte concentration and they illustrate their approach through a practical, real-world example involving food contact materials.

A novel systems‐level approach to unravel the regulation and biosynthetic steps of glycosylation

Protein glycosylation is fundamentally important to most biological processes, and an understanding of how it is regulated is fundamental to our understanding of many diseases and the development of biopharmaceuticals. However, the diversity and complexity of glycosylation have made it difficult to control glycosylation and identify how glycan synthesis is regulated. To address this challenge, we have developed a computational platform using probabilistic modeling of glycan synthesis, which allows us to study how glycosylation is regulated, and to guide glycoengineering efforts. Specifically, our computational approach first leverages known enzyme specificities or possible biosynthetic pathways based on glycan structures. This is used to map out all possible glycans that can be synthesized. Next, glycoprofiling and other omics data are used from control samples to train the model and quantify how glycosyltransferases and metabolic pathways contribute to glycan synthesis under normal conditions. Here I will discuss a few applications of this modeling framework for glycoengineering and biological discovery to identify how regulatory proteins control glycosylation in the cell. First, by coupling the framework with a genetic algorithm, we can predict the specific genetic and bioprocess modifications that are necessary to obtain a desired glycoprofile. Second, the framework can be used to gain deeper insights into how glycosylation is controlled by more distal regulators in the secretory pathway. Third, we can use the framework to identify which glycosyltransferases are associated with specific biosynthetic steps in incompletely characterized classes of glycans, such as human milk oligosaccharides. Thus, despite the complexity of glycosylation, novel systems biology approaches now provide tools to unravel its regulation, discover novel insights regarding their synthesis, and aid us in glycoengineering. Support or Funding Information The Novo Nordisk Foundation through the Center for Biosustainability at the Technical University of Denmark (NNF10CC1016517) and from NIH (R35 GM119850 and R21 HD080682) Our novel modeling framework enables the integration of glycan profiling with other omics data (e.g., transcriptomics, proteomics, or measured genetic variants), to understand which steps of glycosylation are regulated, predict novel glycosyltransferases for poorly characterized classes of glycans, or guide glycoengineering efforts. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Learning-by-doing: experience from 20 years of teaching LCA to future engineers

In support of the sustainable development of our societies, future engineers should have elementary knowledge in sustainability assessment and use of life cycle assessment. Publications on pedagogical experience with teaching life cycle assessment (LCA) in high-level education are however scarce. Here, we describe and discuss 20 years of experience in teaching LCA at MSc level in an engineering university with the ambition to share our insights and inspire teaching of LCA as part of a university curriculum. We detail the design of an LCA course taught at the Technical University of Denmark since 1997. The course structure relies on (i) a structured combination of theoretical teaching, practical assignments and hands-on practice on LCA case studies, and (ii) the conduct of real-life LCA case studies in collaboration with companies or other organisations. Through the semester-long duration of the course, students from different engineering backgrounds perform full-fledged LCA studies in groups, passing through two iterations—a screening LCA supporting a more targeted LCA. The course design, which relies on a learning-by-doing principle, is transparently described to inspire LCA teachers among the readers. Historical evolution and statistics about the course, including its 192 case studies run in collaboration with 105 companies and institutions, are analysed and serve as basis to discuss the benefits and challenges of its different components, such as the theory acquisition, the assignment work, the LCA software learning, the conduct of case studies, the merits of industrial collaborations and grading approaches. We demonstrate the win-win situation created by the setting of the course, in which the students are actively engaged and learn efficiently how to perform an LCA while the collaborating companies often get useful insights into their analysed case studies. The course can also be an eye opener for companies unfamiliar with LCA, who get introduced to life cycle thinking and the potential benefits of LCA. We have no hesitation in recommending industries and LCA teachers to engage into such collaborations even in the fundamental teaching of LCA techniques.

Investigation of Lipid Oxidation in the Raw Materials of a Topical Skin Formulation: A Topical Skin Formulation Containing a High Lipid Content

AbstractSeveral studies have demonstrated that lipid oxidation often occurs in topical skin formulations which can affect product odor (both positively and negatively). Furthermore, odor detection threshold values and odor descriptors of identified volatile oxidation products in cleansing and skin cream formulation prototypes were recently determined by a trained sensory panel at the Technical University of Denmark in the Division of Food Technology. In this study, we investigated lipid oxidation in a prototype skin cream formulation as well as in selected cosmetic skin care raw materials. Lipid oxidation was measured regularly over a six‐month period for the product and over a three‐month period for the raw materials by headspace gas chromatography–mass spectrometry. The volatile compound present in the highest initial concentration, and which increased most during storage, was 3‐methyl‐1‐butanol (medicinal, chemical/cleaning agent odor), and its formation was linked to the raw material isoamyl p‐methoxycinnamate. The odor character of the product after storage was assessed and informally deemed acceptable for consumer usage and typical of topical dermocosmetic products. A potential pathway for its formation was also identified. In addition, the concentrations of several well‐known lipid oxidation products increased during storage and were suggested to originate primarily from rice bran wax, which oxidized more readily than other raw materials due to its unsaturated nature.

The Debye-Hückel theory and its importance in modeling electrolyte solutions

A colleague at the Technical University of Denmark has often stated: “Life is too short for electrolytes”. Another well-known scientist in the field of molecular simulation has recently said during an international Thermodynamics conference: “All my life I have tried to keep myself away from water and electrolytes”. Sadly, what these statements correctly imply is that there are far too many unclear questions and concepts in electrolyte thermodynamics, and associated difficulties in modeling electrolyte solutions. In this work, we attempt to shed some light on some important concepts and misconceptions in electrolyte thermodynamics associated with the development of electrolyte equations of state, with emphasis on those based on the Debye-Hückel theory. Detailed mathematics is needed for some of the derivations but for brevity and in order to emphasize the principles rather than the derivations, the latter are omitted. We first discuss the peculiarities of electrolyte thermodynamics and associated modeling and continue with a literature review of equations of state for electrolyte solutions. Next we will provide a modern derivation of the Debye-Hückel and Born equations and discuss their assumptions in detail to answer some of the confusion that exists in current literature on the applicability ranges and show how the different versions of the Debye-Hückel and Born models are related. A discussion and outlook section conclude this review. Several of the statements in this work challenge “accepted beliefs” in electrolyte thermodynamics and, while we believe that this challenge is justified, we hope that a useful debate can result in improved and predictive thermodynamic models for electrolyte solutions.

Sustainability and LCA in Engineering Education – A Course Curriculum

Educating engineering students in sustainability is becoming increasingly important since engineering is expected to play a vital role in solving the sustainability challenges facing us. At the Technical University of Denmark this awareness is visible in the strategy where sustainability is expected to be an integrated part of all study programmes. The division for Quantitative Sustainability Assessment (QSA) aims to provide this competence to the DTU students. QSA focus mainly on Life Cycle Assessment based methods but have designed a course curriculum that can provide different levels of sustainability competences to students with a progression of complexity from the bachelor to the master or even PhD level. This role is unique since LCA is not systematically a component of engineering studies today. We present and discuss our experience with attempts to integrate LCA and life cycle thinking in an educational curriculum to teach sustainability broadly to engineering students at DTU. A main challenge is how to integrate the teaching into study programmes and eventually how to accommodate an increasing number of students on the individual courses.

Promoting sustainability through national transport planning

This following special issue of the European Journal of Transport Infrastructure Research (EJTIR) containing 4 scientific papers is the result of the work conducted under the research project ‘National Transport Planning – Sustainability, Institutions and Tools’ (SUSTAIN) (2012- 2017) financed by the Danish Innovation Fund. SUSTAIN was coordinated by first the Department of Transport of the Technical University of Denmark (DTU Transport) and later as the result of a reorganisation of the transport research at DTU by the Department of Management Engineering (DTU Management Engineering). The project was carried out in cooperation with several Danish and international partners. In SUSTAIN the following definition of national sustainable transport planning (NSTP) was adopted: deliberate, knowledge-based, and strategic endeavours to integrate sustainability principles, criteria and goals in the development, management, regulation and assessment of nationally significant transport systems and services. This paper presents the research outcome by reviewing some of the major findings and seeing these collectively as a basis for promoting sustainability through the formulated research topic of NSTP. This basis includes defining criteria and indicators for use in NSTP combining evidence-based and performance oriented planning approaches. Furthermore, it contains a flexible evaluation framework that includes a decision support model that when informed by criteria and indicators can structure and assist an NSTP practice. This practice can support a planning process aiming at realising a sustainable transport development. Finally, the basis comprises a review of the complex political and administrative fabric in which NSTP is embedded, and thereby it can condition the ability to promote sustainability in practice.

Towards High Power Density Metal Supported Solid Oxide Fuel Cell for Mobile Applications

For use of metal supported solid oxide fuel cell (MS-SOFC) in mobile applications it is important to reduce the thermal mass to enable fast startup, increase stack power density in terms of weight and volume and reduce costs. In the present study, we report on the effect of reducing the Technical University of Denmark (DTU) SoA MS-SOFCs support layer thickness from 313 μm gradually to 108 μm. The support layer thickness decrease in the DTU co-sintering MS-SOFC fabrication route results in an increased densification of the support layer and a slight decrease in performance. To mitigate the performance loss, two different routes for increasing the porosity of the support layer and thus performance were explored. The first route is the introduction of gas channels by puncturing of the green tape casted support layer. The second route is modification of the co-sintering profile. In summary, the cell thickness and thus weight and volume was reduced and the cell power density at 0.7 V at 700°C was increased by 46% to 1.01 Wcm−2 at a fuel utilization of 48%. All modifications were performed on a stack technological relevant cell size of 12 cm × 12 cm.

An evolving experience learned for modelling thermal dynamics of buildings from live experiments: the Flexhouse story

This paper shares an evolving experience learned for modelling the thermal dynamics of buildings from live experiments run in Flexhouse1 at Risø Campus of Technical University of Denmark (DTU). Among different trials, circuit based grey-box models approach have been developed and improved from time to time. Although the intension of modelling the thermal dynamics of Flexhouse1 remains unchanged, the details of experiments and applied modelling approach do evolve over time due to the increase of knowledge and the improvement made to the experimental platform. In addition to presenting a summary of these details, additional suggestions on future improvements are discussed and preliminarily investigated.

Diel vertical interactions between Atlantic cod Gadus morhua and sprat Sprattus sprattus in a stratified water column

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 583:195-209 (2017) - DOI: https://doi.org/10.3354/meps12319 Diel vertical interactions between Atlantic cod Gadus morhua and sprat Sprattus sprattus in a stratified water column Niels G. Andersen*, Bo Lundgren, Stefan Neuenfeldt, Jan E. Beyer Technical University of Denmark, National Institute of Aquatic Resources (DTU-Aqua), Charlottenlund Castle, 2920 Charlottenlund, Denmark *Corresponding author: nga@aqua.dtu.dk ABSTRACT: Information about species interactions at a spatial scale comparable to the perceptive abilities of the involved species is crucial for establishment of predictive food consumption models at the population level. Nevertheless, such information is sparse due to methodological constraints. We studied the diel vertical dynamics of species interactions between Atlantic cod Gadus morhua and its major clupeid prey, sprat Sprattus sprattus, at a location in the Bornholm Basin of the central Baltic Sea during late winter. This was accomplished by combining acoustic information on diel vertical fish distribution, time of ingestion of individual sprat estimated from cod stomach content data and observed vertical profiles of salinity, temperature and oxygen content. Predation by cod took place primarily at dusk and dawn during ascent and descent of sprat associated with school dissolution and formation, respectively. Cod resided close to the bottom outside these temporal predation windows. Sprat schools were located at the same depth as cod in the daylight hours, whereas at night dispersed sprat were situated higher in the water column. These vertical dynamics could be explained by fitness optimization using bioenergetics and trade-offs between temperature, oxygen saturation of the water and predation risk. This study forms a first step towards providing a mechanistic background for the predatory impact of cod at the basin scale and beyond. KEY WORDS: Baltic Sea · Stomach content dynamics · Diel feeding cycle · Bioacoustics · Hydrography · Winter situation · Bioenergetics · Fitness optimization Full text in pdf format Supplementary material PreviousNextCite this article as: Andersen NG, Lundgren B, Neuenfeldt S, Beyer JE (2017) Diel vertical interactions between Atlantic cod Gadus morhua and sprat Sprattus sprattus in a stratified water column. Mar Ecol Prog Ser 583:195-209. https://doi.org/10.3354/meps12319 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 583. Online publication date: November 16, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

4th International School and Conference on Optoelectronics, Photonics, Engineering and Nanostructures “Saint Petersburg OPEN 2017”

Editorial PrefaceDear Colleagues,4th International School and Conference “Saint Petersburg OPEN 2017” on Optoelectronics, Photonics, Engineering and Nanostructures was held on April 3 - 6, 2017 at St. Petersburg Academic University. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology. The keynote speakers wereAlexey Toropov (Ioffe Physical Technical Institute RAS, Russia)Leonid Karachinsky (Connector Optics LLC, Russia)Sergei Alexandrov (Peter the Great St Petersburg Polytechnic University, Russia)Sergey Morozov (Institute for Physics of Microstructures RAS, Russia)Alexander Marmaluk (JSC M. F. Stelmakh Research Institute “Polyus”, Russia)Nika Akopian (Technical University of Denmark, Denmark)Anatoly Evstrapov (Institute for Analytical Instrumentation RAS, Russia)Seppo Honkanen (University of Eastern Finland, Finland)During the poster session all undergraduate and graduate students attending the conference presented their works. Sufficiently large number of participants with 286 student attendees from all over the world allowed the Conference to provide a fertile ground for the fruitful discussions between the young scientists as well as to become a perfect platform for the valuable discussions between student authors and highly experienced scientists. The best student papers, which were selected by the Program Committee and by the invited speakers basing on the theses and their poster presentation, were awarded with diplomas of the conference and prizes.List of The head of Program Committee, The head of Organizing Committee, The invited speakers, Poster Session, Elevator speech session, Award ceremony are available in this PDF.

Reply to “Comment on ‘Reliable Correlation for Liquid–Liquid Equilibria outside the Critical Region’”

RETURN TO ISSUEPREVComment/ReplyNEXTReply to “Comment on ‘Reliable Correlation for Liquid–Liquid Equilibria outside the Critical Region’”Łukasz Ruszczyński†, Alexandr Zubov†, John P. O’Connell‡, and Jens Abildskov*†View Author Information† PROSYS, Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800 Kongens Lyngby, Denmark‡ Department of Chemical Engineering, University of Virginia, 102 Engineers’ Way, Charlottesville, Virginia 22904-4741, United States*E-mail: [email protected]Cite this: J. Chem. Eng. Data 2017, 62, 11, 4043–4044Publication Date (Web):October 12, 2017Publication History Received10 August 2017Accepted28 September 2017Published online12 October 2017Published inissue 9 November 2017https://doi.org/10.1021/acs.jced.7b00724Copyright © 2017 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views215Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (215 KB) Get e-AlertsSUBJECTS:Liquid liquid equilibrium,Amorphous materials,Water,Stability Get e-Alerts

Post‐buckling strength of plate girders subjected to shear – experimental verification

AbstractThis paper describes a calculation method for steel plate girders with transverse web stiffeners subjected to shear. It may be used to predict the failure load or, as a design method, to determine the optimal number of internal web stiffeners. The method is based on the theory of plasticity. Many other theories have been developed, but the method presented here differs from these theories by incorporating the strength of the transverse stiffeners and by assuming that the tensile bands may pass the transverse stiffeners – an effect often observed in tests. Other methods have only dealt with a single web field between two stiffeners.The load‐carrying capacity may be predicted by applying both the lower‐bound and upper‐bound theorems. The upper‐bound solutions show very good correlation with existing tests. The emphasis is placed on the presentation of the tests conducted at the Technical University of Denmark. The test programme comprised six full‐scale plate girder specimens. Agreement between the theory and the tests is very good.

Direction of arrival estimation using local series expansion evaluated on acoustic data

Direction of arrival (DOA) estimation using a local series expansion of the signal is evaluated on acoustic data. It was recently proposed that DOA estimation using a sensor array could be performed using a local temporal/spatial series expansion. That is, to use the local phase of the signal rather than its estimated second order moments or correlation as in classical methods. The approach should provide easier handling of general sensor configurations, ability to deal with very low sampling rates and few samples, and benefits from miniature sensor configurations. Additionally, the signal is not required to be narrow-banded, as sufficient smoothness is enough. Here, the local series expansion method is benchmarked to a standard beam-forming method using experimental data, recorded in an anechoic chamber at the Technical University of Denmark (DTU). The dataset was recorded using 52 high quality microphones distributed on a sphere with radius 50 mm, and contains several recordings from one or two well defined sources from several different directions, with different levels of reverberation. The dataset is used to evaluate important aspects of the new method and its potential to improve on standard DOA methods.

An unexpected but fulfilling path: From a Hunt Postdoctoral Research Fellowship in Denmark to academia in Nebraska

As the 1998-99 Hunt Postdoctoral Research Fellowship recipient, I conducted postdoctoral research at the Technical University of Denmark under the supervision of Prof. Anders Christian Gade. My goal as a teenager was to become an acoustical engineer who designed concert halls, after reading about such a job from a high school physics textbook. After receiving my Bachelor’s of Science degree in Civil Engineering, I had planned to get a Master’s degree in Acoustics from the Pennsylvania State University and then become an acoustical consultant; I certainly had no intention of pursuing a Ph.D., a postdoc, or an academic position. I was fortunate, though, to have had mentors who guided me on an unexpected but fulfilling career path: first in getting my Ph.D. instead of Master’s degree, then applying and receiving the Hunt Postdoctoral Research Fellowship to study abroad in Europe during which I made firm connections to other strong architectural acoustics groups, and finally becoming a faculty member at the U...

RADIATION PROTECTION MEASUREMENTS WITH THE VARIANCE-COVARIANCE METHOD IN THE STRAY RADIATION FIELDS FROM PHOTON AND PROTON THERAPY FACILITIES.

The microdosimetric variance-covariance method was used to study the stray radiation fields from the photon therapy facility at the Technical University of Denmark and the scanned proton therapy beam at the Skandion Clinic in Uppsala, Sweden. Two TEPCs were used to determine the absorbed dose, the dose-average lineal energy, the dose-average quality factor and the dose equivalent. The neutron component measured by the detectors at the proton beam was studied through Monte Carlo simulations using the code MCNP6. In the photon beam the stray absorbed dose ranged between 0.3 and 2.4 μGy per monitor unit, and the dose equivalent between 0.4 and 9 μSv per monitor unit, depending on beam energy and measurement position. In the proton beam the stray absorbed dose ranged between 3 and 135 μGy per prescribed Gy, depending on detector position and primary proton energy.

How Engineers Make Markets Organizing Electricity System Decarbonization

Energy system decarbonization by means of wind power integration has recently been pursued through the introduction of a novel retail electricity market. The market, named EcoGrid, has been designed to facilitate short-term price-responsive electricity consumption. By following the market construction process undertaken by scientists at the Technical University of Denmark, this article shows how engineers have approached the task by designing markets as technical control systems. It is demonstrated that EcoGrid has been designed by modeling a retail electricity market on three different conceptions of control systems as found in the discipline of control systems engineering. By tracing the origins of EcoGrid, this article documents the governing of electricity consumers through what we here call a synthetic market, i.e. a market artifact devised to attain goals. These findings about expertise in electricity market design are then used as a springboard to discuss the implications of introducing markets as a means of governance.