702 research outputs found
Complex energy simlulation using simplified user interaction mechanisms
Simulation of energy systems and associated thermodynamic domains is very powerful in delivering precise information at high resolution. Modelling software requires detailed information about the energy system. The specialised user usually has questions about specific aspects of the energy system and may not be interested in the complete set of outputs available from simulation results. Similarly the specialised user may only be concerned about a subset of the inputs provided to the software. This suggests an opportunity to develop an input / output scheme tailored for the specialised user. The power of simulation can be accessed through the use of simplified interfaces. Although these restrict flexibility in terms of model input / output data the specialised user is only interested in a subset of the capability of the underlying simulation tool. Robust results rely on a consistent underlying simulation context, this restricted interface ensures that only the parameters of interest to the users are modifiable and that other simulation parameters remain fixed ensuring a consistent and repeatable output. One such example of limited user interaction for both output and input is the ADEPT interface to whole building and plant dynamic modelling and simulation suite ESPr (ESRU 2002). The interface was developed in the context of the UK domesticheating market. This paper describes the development of the ADEPT tool and associated spreadsheet templates in order to provide a readily usable platform for the study of domestic heating systems and controls for plant and control components manufacturers, regulatory authorities and research organisations
Development and validation of detailed building, plant and controller modelling to demonstrate interactive behaviour of system components
As plant modelling becomes capable of more complexity and detailed resolution, new opportunities arise for the virtual evaluation of discrete plant components such as flow control and energy conversion devices, and controllers. Such objects are conventionally developed and tested at the prototype stage in a laboratory environment. Designers now seek to use modelling technology to extend their understanding from limited laboratory test results to full building and plant system analysis. This paper describes the development of a modelling system, using ESP-r, for typical United Kingdom domestic house types with hydronic gas or oil fired central heating including radiator and underfloor heating systems, and with a variety of conventional or advanced control types. It demonstrates the ability of detailed building and plant modelling to reveal unexpected insights into how real control systems perform in combination with other plant items and in different building types, including estimation of their influence on annual energy consumption. Comparisons with measurements taken in test rooms confirm that the observed behaviour of controls is realised in practice. The authors conclude that the complex dynamic interactions that take place between the various elements that make up a real building energy system have an important influence on its overall energy performance, revealing causes of variance that cannot be identified by laboratory testing alone, or by simplistic energy assessment tools
Spreadsheet tools to estimate the thermal transmittance and thermal conductivities of gas spaces of an Insulated Glazing Unit
An Insulated Glazing unit (IGU) is constructed with two or more layers of glass panes sealed together by gas spaces in-between. IGUs are prevalent in windows, doors and rooflights, primarily due to their improved thermal resistance. Today, most IGUs are either two or three layered. Adding further layers of glass improves thermal insulation but with the penalty of increased cost and weight. Low emissivity (Low-e) film coatings, when deposited on the glass panes, reduce long-wavelength radiative heat losses. Furthermore, filling the gas spaces with the inert gases (e.g. Argon, Krypton, Xenon and SF6), further reduce conduction and natural convection across the gap. In summary, higher thermal insulation performance of an IGU can be achieved with gas fillings and Low-e coatings on glass. This report discusses spreadsheets that have been developed, capable of estimating the thermal transmittance values of IGU, as per BS EN 673. The spreadsheet tools also have the ability to estimate the thermal conductivity of the gas spaces between the panes of IGU
The Varied Fates of z~2 Star-forming Galaxies
Star-forming galaxies constitute the majority of galaxies with stellar masses
>10^10 M_Sun/h^2 at z~2 and dominate the star-formation rate density of the
Universe at this early epoch. It is thus critical to understand their origins,
evolution, and connection to the underlying dark matter distribution. To this
end, we identify the dark matter halos (including subhalos) that are likely to
contain star-forming galaxies at z~2 (z2SFGs) within a large dissipationless
cosmological simulation and then use halo merger histories to follow the
evolution of z2SFG descendants to z~1 and z~0. The evolved halos at these
epochs are then confronted with an array of observational data in order to
uncover the likely descendants of z2SFGs. Though the evolved halos have
clustering strengths comparable to red galaxies at z~1 and z~0, we find that
the bulk of z2SFGs do not evolve into red galaxies, at either epoch. This
conclusion is based primarily on the fact that the space density of z2SFGs is
much higher than that of lower redshift red galaxies, even when accounting for
the merging of z2SFG descendants, which decreases the number density of z2SFG
descendants by at most a factor of two by z~0. Of the ~50% of z2SFGs that
survive to z~0, ~70% reside at the center of z~0 dark matter halos with M>10^12
M_Sun/h. Halo occupation modeling of z~0 galaxies suggests that such halos are
occupied by galaxies with M_r<-20.5, implying that these z2SFGs evolve into
``typical'' ~ L* galaxies today, including our own Galaxy. The remaining ~30%
become satellite galaxies by z~0, and comparison to halo occupation modeling
suggests that they are rather faint, with M_r<-19.5. (ABRIDGED)Comment: 13 pages, 5 figures. ApJ in pres
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The internet of food things: Adding values to the digitalisation of the UK food supply chain
The Internet of Things (IoT) is beginning to have a pronounced impact on the digitalised food manufacturing chain. Whilst the food chain is becoming at once more complex and more critical, the application of IoT has begun to be recognised as a key component of this transformation. However, exactly what the IoT is, or is not, is both evolving and provoking a lively debate. New clarifiers are being added to the term such as the Internet of Industrial Things and the Autonomous Internet of Things to ostensibly help clarify the terminology. For the purposes of the Internet of Food Things Network Plus, our conceptual and physical platform is predicated on the idea of a secure and trustworthy network based on open standards, where-possible commodity devices, and underpinned by societally ratified regulatory arrangements
Compact ring-based X-ray source with on-orbit and on-energy laser-plasma injection
We report here the results of a one week long investigation into the
conceptual design of an X-ray source based on a compact ring with on-orbit and
on-energy laser-plasma accelerator. We performed these studies during the June
2016 USPAS class "Physics of Accelerators, Lasers, and Plasma..." applying the
art of inventiveness TRIZ. We describe three versions of the light source with
the constraints of the electron beam with energy or
and a magnetic lattice design being normal conducting (only for the
beam) or superconducting (for either beam). The electron beam
recirculates in the ring, to increase the effective photon flux. We describe
the design choices, present relevant parameters, and describe insights into
such machines.Comment: 4 pages, 1 figure, Conference Proceedings of NAPAC 201
Comparison of Supine and Vertical Bioimpedance Measurements in Young Adults
Topics in Exercise Science and Kinesiology Volume 3: Issue 1, Article 11, 2022. Bioelectrical impedance analysis (BIA) methods estimate health parameters such as phase angle (PhA) and body fat percentage (%BF) from various positional and electrode configurations. PhA and %BF are known biological markers of cellular and physical health, respectively, and can be used to predict various health-related conditions and therefore require accurate assessment. The purpose of this study was to evaluate the effect of body position during BIA by investigating the difference and agreement between PhA and %BF using RJL (supine) and InBody (vertical) analyzers. Thirty-eight young adults (23.4±4.1 yrs.) volunteered and underwent body composition assessments by both analyzers. Difference and agreement in assessments of PhA and %BF between analyzers were assessed using paired samples t-tests and Lin’s concordance correlation coefficient (rc), respectively. RJL’s PhA (7.15±0.84°) exceeded InBody’s (6.11±0.74°), p\u3c0.001, and had poor agreement (rc =0.47). RJL’s %BF (23.0±6.8%) was similar to InBody’s (23.1±7.4%), p=0.813, and had substantial agreement (rc =0.95). Both analyzers estimated %BF similarly and may be interchangeable for this purpose, thus demonstrating no effect of body position on the estimation of %BF with these BIA devices. An individual\u27s PhA may be underestimated if measured in the vertical position and compared to supine reference values. Current reference values for PhA are based on measurements in the supine position, so until vertical reference values of PhA are available, caution is urged when interpreting PhA from vertical BIA assessments
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