Design Methodology of Large-Scale Thermoelectric Generation: A Hierarchical Modeling Approach

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Min Chen ◽  
Junling Gao ◽  
Zhengdong Kang ◽  
Jianzhong Zhang
Keyword(s):  
Integrated Circuit ◽  
Large Scale ◽  
Hierarchical Modeling ◽  
Waste Heat ◽  
System Modeling ◽  
Electric Circuit ◽  
System Level ◽  
Field Calculation ◽  
Thermoelectric Generation ◽  
Level Model

A thermoelectric generation system (TEGS) used in the practical industry of waste heat recovery consists of the fluidic heat sources, the external load circuitry, and many thermoelectric modules (TEMs) connected as a battery bank. In this paper, a system-level model is proposed to seamlessly integrate the complete fluid-thermal-electric-circuit multiphysics behaviors in a single circuit simulator using electrothermal analogy. First, a quasi one-dimension numerical model for the thermal fluids and their nonuniform temperature distribution as the boundary condition for TEMs is implemented in simulation program with integrated circuit emphasis (SPICE)-compatible environment. Second, the electric field calculation of the device-level model is upgraded to reflect the resistive behaviors of thermoelements, so that the electric connections among spatially distributed TEMs and the load circuitry can be freely combined in the simulation. Third, a hierarchical and TEM-object oriented strategy are developed to make the system modeling as well as the design scalable, flexible, and programmable. To validate the proposed system model, a TEGS, including eight TEMs is constructed. Through comparisons between simulation results and experimental data, the proposed model shows sufficient accuracy so that a straightforward cooptimization of the entire TEGS of large scale can be carried out.

Research on Integration Design of Automobile Waste Heat Thermoelectric Generation Exchanger and Engine Muffler

2014 ◽  
Vol 494-495 ◽  
pp. 51-54
Author(s):  
Jiao Long Xie
Keyword(s):  
Large Scale ◽  
Thermoelectric Generator ◽  
High Efficiency ◽  
Waste Heat ◽  
Thermoelectric Module ◽  
Structural Complexity ◽  
Exhaust System ◽  
Thermoelectric Generation ◽  
Technical Issue ◽  
Structural Integration

The thermoelectric generator (TEG) recovering waste heat from the exhaust has became a potential technical issue, due to its characters of pollution-free, no moving parts, reliability and high efficiency. There exist arrangement on the chassis and the exhaust backpressure of whole system will increase of these two problems, when integrating TEG in the car of TEG and the muffler is to integrate the thermoelectric module on the surface muffler, it can effectively reduce the size of TEG, also reduce its weight and structural complexity. It also reduced the backpressure of TEG, meanwhile solved the compatibility issues with other components of exhaust system. The structural integration laid the foundation to achieve the large-scale use of thermoelectric materials in the car.

Application of Spatial Adaptive Filter in the Tilting Mode of Digital Image Restoration

2013 ◽  
Vol 791-793 ◽  
pp. 1992-1996
Author(s):  
Yan Fei Wang
Keyword(s):  
Image Restoration ◽  
Adaptive Filter ◽  
Digital Image ◽  
Integrated Circuit ◽  
Weight Control ◽  
Large Scale ◽  
Hierarchical Modeling ◽  
Cross Point ◽  
Recovery Method ◽  
Depth Analysis

With the development of computer technology and large scale integrated circuit technology, since 1960s, the development of spatial adaptive filter has become one important part of signal processing, its application field has been extended, especially it is used in the digital image processing, and it has become one of the hot research topics in current. This paper presents the recovery method of introducing spatial adaptive filter in the digital image restoration. Firstly, the spatial adaptive filter theory is described, on the basis of this, the hierarchical modeling equilibrium is proposed in the tilting mode digital image restoration, to carry on the analysis of random signal prediction. At the same time, the hierarchical modeling equilibrium will carry out adaptive weight control based on transverse spatial filtering, to reach image restoration for the right cross point. Finally, this paper carries out in-depth analysis for the realization principle of this method, to provide technology support and practical guidance for the research of this field to a certain extent.

Dynamic Modeling of SOFC Cogeneration Systems for Light Commercial Applications

2014 ◽  
Author(s):  
Kevin J. Albrecht ◽  
Robert J. Braun
Keyword(s):  
Steady State ◽  
Waste Heat ◽  
System Level ◽  
System Component ◽  
Part Load ◽  
Load Following ◽  
Balance Of Plant ◽  
Level Model ◽  
Commercial Applications ◽  
Component Models

One potentially attractive application of solid oxide fuel cells (SOFCs) is for combined heat and power (CHP) in light commercial buildings. An SOFC-based CHP system can be employed to efficiently serve building thermal and electric loads, thereby lowering utility bills and offering many distributed generation benefits. It is often desirable to operate SOFCs in a predominately base load manner from a hardware viewpoint. However, systems in practice will experience some load dynamics during their lifetime and furthermore, optimal economic dispatch of CHP systems frequently recommends a load-following strategy. Thus, the present work is motivated by the need to understand the dynamic response capabilities of SOFC-CHP systems. Part-load performance and dynamic load-following capabilities of a 24 kW planar SOFC system for light commercial applications was investigated through computational modeling. The SOFC and balance-of-plant component models were implemented in gPROMS modeling software. The modeling strategy of each system component and associated transients are discussed. A dynamic SOFC channel-level model, which has been verified against experimental cell data, was integrated with additional balance-of-plant (BOP) component models consisting of a fuel reformer, tail gas combustor, turbomachinery, heat exchangers, and bypass valves. The performance of the system at part-load operation displays increases in electrical efficiency and decreases in CHP efficiency, as well as a more uniform PEN temperature profile. Modeling comparisons between the responses of systems consisting of either dynamic or steady-state BOP component models are reported. A fully dynamic system-level model displays anodic fuel depletion effects and waste heat recovery transients not captured by the steady-state models. The dynamics influence the ability of an SOFC system to load follow indicating when thermal and electric storage may be necessary.

Building a Culture of Ethical, Comparable, Authentic Assessment

2019 ◽  
pp. 463-481
Author(s):  
Andrew Reid ◽  
Julie Ballantyne
Keyword(s):  
Teaching And Learning ◽  
Large Scale ◽  
Authentic Assessment ◽  
Subject Area ◽  
Music Educators ◽  
System Level ◽  
Diverse Range ◽  
Effective Learning ◽  
School Based ◽  
The Subject

In an ideal world, assessment should be synonymous with effective learning and reflect the intricacies of the subject area. It should also be aligned with the ideals of education: to provide equitable opportunities for all students to achieve and to allow both appropriate differentiation for varied contexts and students and comparability across various contexts and students. This challenge is made more difficult in circumstances in which the contexts are highly heterogeneous, for example in the state of Queensland, Australia. Assessment in music challenges schooling systems in unique ways because teaching and learning in music are often naturally differentiated and diverse, yet assessment often calls for standardization. While each student and teacher has individual, evolving musical pathways in life, the syllabus and the system require consistency and uniformity. The challenge, then, is to provide diverse, equitable, and quality opportunities for all children to learn and achieve to the best of their abilities. This chapter discusses the designing and implementation of large-scale curriculum as experienced in secondary schools in Queensland, Australia. The experiences detailed explore the possibilities offered through externally moderated school-based assessment. Also discussed is the centrality of system-level clarity of purpose, principles and processes, and the provision of supportive networks and mechanisms to foster autonomy for a diverse range of music educators and contexts. Implications for education systems that desire diversity, equity, and quality are discussed, and the conclusion provokes further conceptualization and action on behalf of students, teachers, and the subject area of music.

scholarly journals Design and Implementation of a Farrow-Interpolator-Based Digital Front-End in LTE Receivers for Carrier Aggregation

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 231
Author(s):  
Chester Sungchung Park ◽  
Sunwoo Kim ◽  
Jooho Wang ◽  
Sungkyung Park
Keyword(s):  
Integrated Circuit ◽  
Building Block ◽  
Orthogonal Frequency Division Multiplexing ◽  
Critical Path ◽  
Phase Error ◽  
System Level ◽  
Comb Filter ◽  
Carrier Aggregation ◽  
Path Delay ◽  
Front End

A digital front-end decimation chain based on both Farrow interpolator for fractional sample-rate conversion and a digital mixer is proposed in order to comply with the long-term evolution standards in radio receivers with ten frequency modes. Design requirement specifications with adjacent channel selectivity, inband blockers, and narrowband blockers are all satisfied so that the proposed digital front-end is 3GPP-compliant. Furthermore, the proposed digital front-end addresses carrier aggregation in the standards via appropriate frequency translations. The digital front-end has a cascaded integrator comb filter prior to Farrow interpolator and also has a per-carrier carrier aggregation filter and channel selection filter following the digital mixer. A Farrow interpolator with an integrate-and-dump circuitry controlled by a condition signal is proposed and also a digital mixer with periodic reset to prevent phase error accumulation is proposed. From the standpoint of design methodology, three models are all developed for the overall digital front-end, namely, functional models, cycle-accurate models, and bit-accurate models. Performance is verified by means of the cycle-accurate model and subsequently, by means of a special C++ class, the bitwidths are minimized in a methodic manner for area minimization. For system-level performance verification, the orthogonal frequency division multiplexing receiver is also modeled. The critical path delay of each building block is analyzed and the spectral-domain view is obtained for each building block of the digital front-end circuitry. The proposed digital front-end circuitry is simulated, designed, and both synthesized in a 180 nm CMOS application-specific integrated circuit technology and implemented in the Xilinx XC6VLX550T field-programmable gate array (Xilinx, San Jose, CA, USA).

scholarly journals A Review on Terahertz Technologies Accelerated by Silicon Photonics

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1646
Author(s):  
Jingya Xie ◽  
Wangcheng Ye ◽  
Linjie Zhou ◽  
Xuguang Guo ◽  
Xiaofei Zang ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Silicon Photonics ◽  
Large Scale ◽  
Cost Effective ◽  
Single Chip ◽  
Photonic Integrated Circuit ◽  
Hybrid Silicon ◽  
The Cost ◽  
Silicon Based ◽  
Thz Applications

In the last couple of decades, terahertz (THz) technologies, which lie in the frequency gap between the infrared and microwaves, have been greatly enhanced and investigated due to possible opportunities in a plethora of THz applications, such as imaging, security, and wireless communications. Photonics has led the way to the generation, modulation, and detection of THz waves such as the photomixing technique. In tandem with these investigations, researchers have been exploring ways to use silicon photonics technologies for THz applications to leverage the cost-effective large-scale fabrication and integration opportunities that it would enable. Although silicon photonics has enabled the implementation of a large number of optical components for practical use, for THz integrated systems, we still face several challenges associated with high-quality hybrid silicon lasers, conversion efficiency, device integration, and fabrication. This paper provides an overview of recent progress in THz technologies based on silicon photonics or hybrid silicon photonics, including THz generation, detection, phase modulation, intensity modulation, and passive components. As silicon-based electronic and photonic circuits are further approaching THz frequencies, one single chip with electronics, photonics, and THz functions seems inevitable, resulting in the ultimate dream of a THz electronic–photonic integrated circuit.

scholarly journals Drug Prescription Profiles in Patients with Polypharmacy in Spain: A Large-Scale Pharmacoepidemiologic Study Using Real-World Data

2021 ◽  
Vol 18 (9) ◽  
pp. 4754
Author(s):  
Miguel Ángel Hernández-Rodríguez ◽  
Ermengol Sempere-Verdú ◽  
Caterina Vicens-Caldentey ◽  
Francisca González-Rubio ◽  
Félix Miguel-García ◽  
...  
Keyword(s):  
Psychotropic Drugs ◽  
Large Scale ◽  
Anatomical Therapeutic Chemical ◽  
Drug Prescription ◽  
Age Groups ◽  
System Level ◽  
Real World Data ◽  
Converting Enzyme Inhibitors ◽  
Cross Sectional ◽  
Β Blockers

We aimed to identify and compare medication profiles in populations with polypharmacy between 2005 and 2015. We conducted a cross-sectional study using information from the Computerized Database for Pharmacoepidemiologic Studies in Primary Care (BIFAP, Spain). We estimated the prevalence of therapeutic subgroups in all individuals 15 years of age and older with polypharmacy (≥5 drugs during ≥6 months) using the Anatomical Therapeutic Chemical classification system level 4, by sex and age group, for both calendar years. The most prescribed drugs were proton-pump inhibitors (PPIs), statins, antiplatelet agents, benzodiazepine derivatives, and angiotensin-converting enzyme inhibitors. The greatest increases between 2005 and 2015 were observed in PPIs, statins, other antidepressants, and β-blockers, while the prevalence of antiepileptics was almost tripled. We observed increases in psychotropic drugs in women and cardiovascular medications in men. By patient´s age groups, there were notable increases in antipsychotics, antidepressants, and antiepileptics (15–44 years); antidepressants, PPIs, and selective β-blockers (45–64 years); selective β-blockers, biguanides, PPIs, and statins (65–79 years); and in statins, selective β-blockers, and PPIs (80 years and older). Our results revealed important increases in the use of specific therapeutic subgroups, like PPIs, statins, and psychotropic drugs, highlighting opportunities to design and implement strategies to analyze such prescriptions’ appropriateness.

scholarly journals Integration of enzyme constraints in a genome-scale metabolic model of Aspergillus niger improves phenotype predictions

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingru Zhou ◽  
Yingping Zhuang ◽  
Jianye Xia
Keyword(s):  
Aspergillus Niger ◽  
Large Scale ◽  
Measurement Techniques ◽  
Metabolic Model ◽  
System Level ◽  
Metabolic Phenotype ◽  
Omics Data ◽  
Prediction Ability ◽  
Phenotype Prediction ◽  
Genome Scale

Abstract Background Genome-scale metabolic model (GSMM) is a powerful tool for the study of cellular metabolic characteristics. With the development of multi-omics measurement techniques in recent years, new methods that integrating multi-omics data into the GSMM show promising effects on the predicted results. It does not only improve the accuracy of phenotype prediction but also enhances the reliability of the model for simulating complex biochemical phenomena, which can promote theoretical breakthroughs for specific gene target identification or better understanding the cell metabolism on the system level. Results Based on the basic GSMM model iHL1210 of Aspergillus niger, we integrated large-scale enzyme kinetics and proteomics data to establish a GSMM based on enzyme constraints, termed a GEM with Enzymatic Constraints using Kinetic and Omics data (GECKO). The results show that enzyme constraints effectively improve the model’s phenotype prediction ability, and extended the model’s potential to guide target gene identification through predicting metabolic phenotype changes of A. niger by simulating gene knockout. In addition, enzyme constraints significantly reduced the solution space of the model, i.e., flux variability over 40.10% metabolic reactions were significantly reduced. The new model showed also versatility in other aspects, like estimating large-scale $$k_{{cat}}$$ k cat values, predicting the differential expression of enzymes under different growth conditions. Conclusions This study shows that incorporating enzymes’ abundance information into GSMM is very effective for improving model performance with A. niger. Enzyme-constrained model can be used as a powerful tool for predicting the metabolic phenotype of A. niger by incorporating proteome data. In the foreseeable future, with the fast development of measurement techniques, and more precise and rich proteomics quantitative data being obtained for A. niger, the enzyme-constrained GSMM model will show greater application space on the system level.

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