Phase-change materials, systems and applications for low- and medium-temperature thermal energy storage

Determining the ideal size of compact thermal energy storage containers has been an issue for many building designers due to the difficulty of determining the transient performance of the thermal storage systems. Research and development of compact thermal energy storage systems has been ongoing for more than 80 years with phase change materials (PCMs) used to replace conventional water based thermal stores. PCMs have the potential to store larger amounts of energy when compared to water-based thermal stores over a narrow temperature range, providing a greater thermal storage capacity for the same available volume. This research was undertaken to investigate theoretically and experimentally the thermal behaviour of various PCMs and the overall decarbonisation potential when integrated into current heating and cooling systems. The overall aim was to develop algorithms that could determine optimal and cost effective compact thermal storage geometries and their system integration into the various heating and cooling applications studied. Three operating temperatures were selected based on the application: office space cooling (10 to 24$^\circ$C), residential domestic hot water and space heating (40 to 65$^\circ$C) and district heating (55 to 80$^\circ$C). The algorithms developed predict the energy performance and $CO_2$ emissions reduction for each application with a latent heat thermal storage system compared to a reference (current system design) case in each application. Previous research has focused on the melting behaviour of the PCM within a specific geometry, modelling the heat transfer fluid (HTF) in a separate analysis. The algorithms developed focus on the modelling of these 2 elements simultaneously within the respective application. This provided a useful tool to evaluate the thermal performance of each storage technology compared to the reference case in each application studied. The levelized costs of energy (LCOE) in each application were compared. It was found that in all cases studied, the latent heat thermal energy storage system is an expensive solution, compared to the reference case in each application (72\% more expensive in the office space cooling study, 69\% more expensive in the domestic hot water and space heating study and 9\% more expensive in the district heating study); although the obtained emission reductions are considerable (36\% by shifting daily cooling loads, 57\% by shifting domestic hot water and space heating loads and 11\% by utilizing industrial waste heat via a compact portable thermal store). Further integration of renewable energy sources and the electrification of current heating and cooling applications with the possibility of shifting heating and cooling loads into periods with lower carbon emissions can significantly contribute to meet the UK s 80\% carbon emissions reduction targets by 2050

Compact latent heat storage decarbonization potential for domestic hot water and space heating applications in the UK

A performance comparison is presented for a domestic space and hot water heating system with a conventional gas boiler and an air source heat pump (ASHP) with latent heat storage, both with solar thermal collectors for a typical UK climate, to demonstrate the potential of phase change material based energy storage in active heating applications. The latent heat thermal storage system consisted of 10 modules with RT54HC comprising a total storage capacity of 14.75kWh that provided 53% extra thermal storage capacity over the temperature range of 40 to 65°C compared to a water only store. The simulations predicted a potential yearly CO2 reduction of 56%, and a yearly energy reduction of 76% when operating the heat pumps using the economy 10 electricity tariff i.e a low tariff between 00.00-05.00 and 13.00-16.00 with current grid emission values compared to the conventional gas boiler system; successfully offsetting the electrical load to meet the required heat demand. Due to the high capital costs of the heat pump system with latent heat storage, its levelized cost of energy was 117.84£/MWh, compared to 69.66£/MWh for the gas boiler, on a 20-year life cycle

Thermal energy storage for low and medium temperature applications using phase change materials – a review

A comprehensive review of phase change materials (PCMs) with phase transition temperatures between 0 and 250 °C is presented. From that review, organic compounds and salt hydrates seem more promising below 100 °C and eutectic mixtures from 100 to 250 °C. Practical indirect heat exchanger designs for latent heat storage systems were also assessed and feasible heat enhancement mechanisms reviewed. The focus on this temperature range is due to potential CO2 emissions reduction able to be achieved replacing conventional heating and cooling applications in the domestic, commercial and public administration sectors, which represented around a quarter of the UK’s final energy consumption in 2015

Use of acoustic energy in the processing of molten aluminium alloys

During the last years aluminium alloys have been gaining increased acceptance as structural materials in the automotive and aeronautical industries, mainly due to their light weight, good formability and corrosion resistance. However, improvement of mechanical properties is a constant in research activities, either by the development of new alloys or by microstructure manipulation. This presentation focuses a novel effective dynamic methodology to perform microstructural refinement / modification and degassing of light alloys, namely aluminium alloys, by applying acoustic energy to the melts. High intensity acoustic energy significantly improves the microstructure, therefore the mechanical properties of those alloys, avoiding the use of traditional chemically based degassing and refining techniques which are less effective and present significant environmental impact. Ultrasonic (US) vibration has proven to be extremely effective in degassing, controlling columnar dendritic structure, reducing the size of equiaxed grains and, under some conditions, producing globular grains and modifying the eutectic silicon cells in Al-Si alloys. The mechanisms of US processing of aluminium melts are discussed and experimental results on this field are presented.Fundação para a Ciência e Tecnologia (FCT

Vascular and apoptotic changes in the placode of myelomeningocele mice during the final stages of in utero development

JOAQUIM L. REIS, M.D., PH.D.,1,2 JORGE CORREIA-PINTO, M.D., PH.D.,3,4 MARIANA P. MONTEIRO, M.D., PH.D.,1 MADALENA COSTA, B.SC.,1 AND GROVER M. HUTCHINS, M.D.5 1Department of Anatomy, Abel Salazar Institute for the Biomedical Sciences and Unit for Multidisciplinary Biomedical Research, University of Porto; 2Department of Neurosurgery, Santo António General Hospital; 4Department of Pediatric Surgery, São João Hospital, Porto; 3Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Braga, Portugal; and 5Department of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland Object. Myelomeningocele (MMC) is a primary neurulation defect that is associated with devastating neurological disabilities in affected newborns. To better characterize the in utero neurodegenerative process of MMC, the authors investigated the changes in vascular organization, apoptosis, and the presence of inflammatory cells during gestation by using a mutant mouse model of MMC. Methods. The curly tail/loop tail (ct/lp) mutant mouse model of MMC was chosen to obtain fetuses at different stages of gestation. Mouse fetuses harboring MMC were harvested by caesarean section at embryonic Days 14.5, 16.5, and 18.5 (complete mouse gestation at 19 days, 6 mice/group); littermate fetuses with the same gestational age but without an MMC were used as controls. Samples of the MMC placode or normal spinal cord were stained for immunocytochemical labeling with caveolin antibody (endothelium marker) and activated caspase-3 antibody (apoptosis marker). Samples were morphometrically analyzed with a computer-assisted image analyzer. Results. The MMC mice presented with an increase in vascular density from embryonic Days 16.5–18.5 and an enhanced number of apoptotic cells at embryonic Day 18.5, compared with controls. There were scarce signals of an inflammatory reaction in the MMC placode, as a few infiltrating neutrophils were seen only at embryonic Day 18.5. Conclusions. Fetal placodes in MMC mice showed evidence of increased vascular density since embryonic Day 16.5 and increased apoptosis at embryonic Day 18.5. These new data support the view that in utero changes of the MMC placode, occurring during the last stages of gestation, contribute to the neuropathological manifestations in fullterm newborns with MMC. (DOI: 10.3171/PED/2008/2/8/150

Best Pratice Guide to Manage Vegetation and Promote Biodiversity in Linear Infrastructures

The present guide is based on the experience acquired in the framework of the LIFE LINES project (LIFE14 NAT/PT/001081) and intends to compile and disseminate the recommendable procedures for the management of biodiversity, particularly of plant diversity, in the marginal areas of linear infrastructures, primarily focusing on the national roads, decommissioned railways now used for recreation purposes (ecotrails) and power lines of very high voltage. The guide includes technical information for those in charge of the management of roads, trails and power lines (concession holders, municipalities), for environmental consultancy (Agência Portuguesa do Ambiente, Instituto de Conservação da Natureza e Florestas), and for landscape and agroforestry technicians, as well as for the general public

Seed germination of six Iberian endemic species – a contribution to enhance plant conservation

Biodiversity has been degraded all around the world due to anthropogenic factors. To counteract this worldwide tendency, ecological restoration programs are expanding. In these programs, the use of native herbaceous species, particularly those endemic or threatened, can be promoted by seeding them but germination requirements for most of these species are unknown. Our research meant to fill this gap of information for six Iberian endemic species suitable to use in restoration actions - Digitalis thapsi, Ferula communis subsp. catalaunica, Linaria amethystea subsp. amethystea, Pterocephalidium diandrum, Sanguisorba hybrida, and Silene scabriflora subsp. scabriflora. Their seed germination behaviour was analysed to establish germination protocols for conservation actions. Three germination conditions were used to simulate different sown seasons. Seeds of all species were tested without pretreatment and subjected to a cold stratification. Seeds of S. hybrida and P. diandrum were additionally tested with a scarification treatment. All species reached their better germination performance under autumn conditions (15/10 C; 8/16 hours). In conclusion, for all the six Iberian endemic species tested, germination speed and percentage were suitable for their use in native plants reinforcement

Malignité du christianisme. Le Jugement dernier de Michel-Ange dans l'Histoire de la Peinture en Italie de Stendhal

L\u27analyse stendhalienne des tableaux du quinzième siècle dissimule un violent pamphlet contre l\u27Eglise catholique, et propose une esthétique romantique concurrente de celle du Génie du christianisme de Chateaubriand

Project Proof: Internet Enabled Process Reengineering at J.D. Edwards & Company

J.D. Edwards is a provider of the new generation of ERP and collaborative commerce solutions. This case study describes the challenges faced internally by the company to upgrade to the latest enterprise software it would sell to the world. Dubbed Project PROOF, the project started in June 2001 and was completed in November 2002. The perspectives of the CIO, the program manager, and other key personnel are presented. The case study highlights the issues that arise in an enterprise software implementation project. In addition, the case touches upon issues of project management, process redesign, and marketing. The case study uses a multimedia format to add richness and detail. Although J.D. Edwards was acquired in 2003, the issues discussed are relevant to current business practices

Optimization of the cold profiling process through SMED

In a more and more competitive and industrialized market, it is essential that companies realize that the way forward must go through the optimization of their production processes, reducing the costs and increasing product quality. Nowadays it’s necessary to adopt innovative management models that can provide increased productivity at minimal costs, such as the Lean thinking. The metalworking industry is integrated into one of the most competitive existing markets in Portugal. Given this, it’s fundamental to reduce the waste in all sectors of the production process, using the good Lean principles and practices, such as the Single Minute Exchange of Die, also known as SMED methodology. This paper presents a project of implementing the SMED methodology in the cold profiling process, in a population of five different profiling machines. The results of the SMED implementation show an average OEE improvement of 10,8%.info:eu-repo/semantics/publishedVersio