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11.
Space heating load is decreasing in modern Finnish apartments due to lower U-values of the construction, tight envelopes and heat recovery from exhaust ventilation air. This makes it possible to develop a new combined low temperature water heating system with nominal supply/return water temperatures of 45 °C/35 °C. Such a system includes radiators in rooms and floor heating in bathrooms.In this study, the performance of an apartment building is determined by using dynamic simulation. The simulation results for the combined low temperature water heating system are compared with those for three conventional radiator and floor heating systems. The results show that the combined low temperature water heating system performs well and is able to maintain the zones within the required temperature levels. The thermal comfort analysis indicates that the drifts and ramps in operative temperature using the four studied heating systems are within the limits of Ashrae Standard 55-2004.Temperature measurements in a test room are carried out to find the vertical difference of air temperature using two methods: radiator heating and floor heating. These measurements indicate that there is only a small vertical temperature difference that would not produce any significant thermal discomfort. 相似文献
12.
In this paper, we present a packet-loss resilient system for the transmission of progressively compressed three-dimensional (3D) models. It is based on a joint source and channel coding approach that trades off geometry precision for increased error resiliency to optimize the decoded model quality on the client side. We derive a theoretical framework for the overall system by which the channel packet loss behavior and the channel bandwidth can be directly related to the decoded model quality at the receiver. First, the 3D model is progressively compressed into a base mesh and a number of refinement layers. Then, we assign optimal forward error correction code rates to protect these layers according to their importance to the decoded model quality. Experimental results show that with the proposed unequal error protection approach, the decoded model quality degrades more gracefully (compared to either no error protection or equal error protection methods) as the packet-loss rate increases. 相似文献
13.
We propose Zipper, a compact representation of incidence and adjacency for manifold triangle meshes with fixed connectivity. Zipper uses on average only 6 bits per triangle, can be constructed in linear space and time, and supports all standard random-access and mesh traversal operators in constant time. Similarly to the previously proposed LR (Laced Ring) approach, the Zipper construction reorders vertices and triangles along a nearly Hamiltonian cycle called the ring. The 4.4× storage reduction of Zipper over LR results from three contributions. (1) For most triangles, Zipper stores a 2-bit delta (plus three additional bits) rather than a full 32-bit reference. (2) Zipper modifies the ring to reduce the number of exceptional triangles. (3) Zipper encodes the remaining exceptional triangles using 2.5× less storage. In spite of these large savings in storage, we show that Zipper offers comparable performance to LR and other data structures in mesh processing applications. Zipper may also serve as a compact indexed format for rendering meshes, and hence is valuable even in applications that do not require adjacency information. 相似文献
14.
Urmila Shirwadkar Jarek GlodoEdgar V. van Loef Rastgo HawramiSharmishtha Mukhopadhyay Alexei ChurilovWilliam M. Higgins Kanai S. Shah 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):268-270
Investigations of Ce3+-doped Cs2LiLaBr6 (CLLB) crystals show a systematic trend in their scintillation properties with varying Ce concentrations. The concentration studies provide input in the optimization of growth of the CLLB crystals. Scintillation properties viz. radioluminescence, energy resolution, light yield, decay times, and non-proportionality are discussed for samples from 0% to 20% Ce concentration. 相似文献
15.
At present, ceiling-mounted diffusers are very popular for indoor air distribution, particularly in offices, owing to greater efficiency in the distribution of the air supply and a more comfortable indoor environment. The objective of this study is to construct an effective model to design the indoor airflow of an attached plane jet after its impingement with the corner in a room. In this study, a full-scale test facility was set up to obtain detailed experimental data. One commercial CFD tool, CFX 11.0, was used to simulate the air velocity distribution of an attached plane air jet bounded by the ceiling and an insulated wall. One semi-empirical model was also constructed to predict the impingement jet velocity. The results show that bout the semi-empirical model and CFX 11.0 were able to predict the maximum velocity of an impinging jet at low Reynolds numbers, 1000 and 2000, with an inaccuracy of ±11%. However, the semi-empirical model could be more conveniently used to predict the maximum jet velocity decay after its impingement the corner in a room than CFD simulation in terms of accuracy and the time required to design the indoor airflow pattern. 相似文献
16.
Interest in finding out passive ways to keep the variation in the indoor climate within the comfort zone is gaining in popularity. One possible solution is the use of the moisture-buffering property of materials. In this study, the effects of the ventilation system and moisture-buffering properties of the building fabric on the stability of the indoor temperature and humidity are analysed by means of long-term field measurements. Indoor climate measurements were carried out in 170 detached houses (248 rooms). Temperature and relative humidity were measured continuously in bedrooms and living rooms at one-hour intervals over a one-year period. In general, it may be concluded that in this study, the ventilation had a greater effect on the indoor climate than the properties of the building fabric. The dampening effect of hygroscopic materials was remarkably less in the field measurements than it was in simulations in different studies. This indicates that completely non-hygroscopic and fully hygroscopic houses do not exist in reality. The hygroscopic mass of furniture, textiles, etc. is probably a factor that plays a significant role in indoor humidity, as do real air change rates, including window airing. Simulation tools need to be modified in order to be able also to handle furniture, textiles, and books, etc. 相似文献
17.
Emmanuelle Castagnoli Peter Backlund Oskari Talvitie Tapani Tuomi Arja Valtanen Raimo Mikkola Hanna Hovi Katri Leino Jarek Kurnitski Heidi Salonen 《Indoor air》2019,29(6):903-912
Degrading 2‐ethylhexyl‐containing PVC floorings (eg DEHP‐PVC floorings) and adhesives emit 2‐ethylhexanol (2‐EH) in the indoor air. The danger of flooring degradation comes from exposing occupants to harmful phthalates plasticisers (eg DEHP), but not from 2‐EH as such. Since the EU banned the use of phthalates in sensitive applications, the market is shifting to use DEHP‐free and alternative types of plasticisers in PVC products. However, data on emissions from DEHP‐free PVC floorings are scarce. This study aimed at assessing the surface and bulk emissions of two DEHP‐free PVC floorings over three years. The floorings were glued on the screed layer of concrete casts at 75%, 85%, and 95% RH. The volatile organic compounds (VOCs) were actively sampled using FLEC (surface emissions) and micro‐chamber/thermal extractor (µ‐CTE, bulk emissions) onto Tenax TA adsorbents and analyzed with TD‐GC‐MS. 2‐EH, C9‐alcohols, and total volatile organic compound (TVOC) emissions are reported. Emissions at 75% and 85% RH were similar. As expected, the highest emissions occurred at 95% RH. 2‐EH emissions originated from the adhesive. Because the two DEHP‐free floorings tested emitted C9‐alcohols at all tested RH, it makes the detection of flooring degradation harder, particularly if the adhesive used does not emit 2‐EH. 相似文献
18.
Colorectal cancer (CRC) is one of the most common malignancy and cause of cancer death worldwide, and it still remains a therapeutic challenge for western medicine. There is strong evidence that, in addition to genetic predispositions, environmental factors have also a substantial impact in CRC development. The risk of CRC is attributed, among others to dietary habits, alcohol consumption, whereas physical activity, food containing dietary fiber, dairy products, and calcium supplements have a protective effect. Despite progress in the available therapies, surgery remains a basic treatment option for CRC. Implementation of additional methods of treatment such as chemo- and/or targeted immunotherapy, improved survival rates, however, the results are still far from satisfactory. One of the reasons may be the lack of deeper understanding of the interactions between the tumor and different types of cells, including tumor infiltrating granulocytes. While the role of neutrophils is quite well explored in many cancers, role of eosinophils and basophils is often underestimated. As part of this review, we focused on the function of different granulocyte subsets in CRC, emphasizing the beneficial role of eosinophils and basophils, as well as dichotomic mode of neutrophils action. In addition, we addressed the current knowledge on cells of granulocyte origin, specifically granulocytic myeloid derived suppressor cells (Gr-MDSCs) and their role in development and progression of CRC. 相似文献
19.
Kiwilsza Anna Milanowski Bartłomiej Drużbicki Kacper Coy L. Emerson Grzeszkowiak Mikołaj Jarek Marcin Mielcarek Jadwiga Lulek Janina Pajzderska Aleksandra Wąsicki Jan 《Journal of Porous Materials》2015,22(3):817-829
Journal of Porous Materials - Two mesoporous silica materials: MCM-41 and SBA-15 were applied as potential nanocarriers for poorly soluble drug—nimodipine. Drug incorporation was performed... 相似文献
20.
Edgebreaker: connectivity compression for triangle meshes 总被引:10,自引:0,他引:10
Edgebreaker is a simple scheme for compressing the triangle/vertex incidence graphs (sometimes called connectivity or topology) of three-dimensional triangle meshes. Edgebreaker improves upon the storage required by previously reported schemes, most of which can guarantee only an O(t log(t)) storage cost for the incidence graph of a mesh of t triangles. Edgebreaker requires at most 2t bits for any mesh homeomorphic to a sphere and supports fully general meshes by using additional storage per handle and hole. For large meshes, entropy coding yields less than 1.5 bits per triangle. Edgebreaker's compression and decompression processes perform identical traversals of the mesh from one triangle to an adjacent one. At each stage, compression produces an op-code describing the topological relation between the current triangle and the boundary of the remaining part of the mesh. Decompression uses these op-codes to reconstruct the entire incidence graph. Because Edgebreaker's compression and decompression are independent of the vertex locations, they may be combined with a variety of vertex-compressing techniques that exploit topological information about the mesh to better estimate vertex locations. Edgebreaker may be used to compress the connectivity of an entire mesh bounding a 3D polyhedron or the connectivity of a triangulated surface patch whose boundary need not be encoded. The paper also offers a comparative survey of the rapidly growing field of geometric compression 相似文献