Search results for "CONSTRUCTION"
showing 10 items of 2670 documents
Size control of InAs∕InP(001) quantum wires by tailoring P∕As exchange
2004
The size and emission wavelength of self-assembled InAs∕InP(001) quantum wires (QWrs) is affected by the P∕As exchange process. In this work, we demonstrate by in situ stress measurements that P∕As exchange at the InAs∕InP interface depends on the surface reconstruction of the InAs starting surface and its immediate evolution when the arsenic cell is closed. Accordingly, the amount of InP grown on InAs by P∕As exchange increases with substrate temperature in a steplike way. These results allow us to engineer the size of the QWr for emission at 1.3 and 1.55 μm at room temperature by selecting the range of substrate temperatures in which the InP cap layer is grown.
Experimental characterization of a novel configuration of thermoelectric refrigerator with integrated finned heat pipes
2021
Abstract Thermoelectric refrigerating systems (TER) are environment-friendly technologies. They have several advantages such as low maintenance costs, are less cumbersome and long lifetime. However, these systems have low coefficient of performance and are limited in achieving low temperature levels. This study investigates a new configuration of TE refrigerator employing a novel arrangement of heat sinks with integrated flat and finned heat pipes. A mathematical model is firstly developed to predict transient temperatures and cooling limit time. An experimental characterization is then performed and it includes optimization of energy consumption, cooling time, temperature levels and TE ref…
Evaluation of building heating loads with dimensional analysis: Application of the Buckingham π theorem
2017
Abstract A detailed assessment of building energy performance requires a large amount of input data concerning building typology, environmental conditions, envelope thermophysical properties, geometry, control strategies, and several other parameters. Notwithstanding, the use of specialized software tools poses many challenges in regards to the retrieval of reliable and detailed information, setting a steep learning curve for engineers and energy managers. To speed up the preliminary assessment phase, it might be more convenient to resort to a simplified model that allows the evaluation of heating energy demand with a good level of accuracy and without excessive computational cost or user e…
Effect of material and geometric parameters on natural convection heat transfer over an eccentric annular-finned tube
2019
In this work, the performance of an eccentric annular finned tube heat exchanger under natural convection conditions has been investigated numerically. The objective of the study is to analyse the ...
Mechanism of Antibacterial Activity via Morphology Change of α-AgVO3: Theoretical and Experimental Insights
2017
The electronic configuration, morphology, optical features, and antibacterial activity of metastable α-AgVO3 crystals have been discussed by a conciliation and association of the results acquired by experimental procedures and first-principles calculations. The α-AgVO3 powders were synthesized using a coprecipitation method at 10, 20, and 30 °C. By using a Wulff construction for all relevant low-index surfaces [(100), (010), (001), (110), (011), (101), and (111)], the fine-tuning of the desired morphologies can be achieved by controlling the values of the surface energies, thereby lending a microscopic understanding to the experimental results. The as-synthesized α-AgVO3 crystals display a …
Reclaimed asphalt test specimen preparation assisted by image analysis
2015
This paper presents a laboratory investigation aimed at establishing a protocol for the production of homogeneous asphalt mixtures test specimens, incorporating reclaimed asphalt by using a gyratory compactor with coring and trimming works. Stone mastic asphalt specimens were compacted at the previously identified target densities with the final aim of obtaining specimens with a fixed and homogeneous air void distribution. A microstructural study was conducted to characterize the homogeneity in the air void distribution using X-ray computed tomography (CT) combined with image analysis techniques. The study concluded that the gyratory compactor is suitable for producing homogeneous test spec…
Traditional Architecture and seismic security. Earthquake in the Madonie inner mountain area of Sicily: damages and construction techniques
2017
Tra il 1818 e il 1819 una serie di centri siciliani concentrati nell'area montuosa delle Madonie, furono colpiti a più riprese da una sequenza di scosse sismiche che provocarono numerosi danni all’edificato storico, sia diffuso che di pregio. Il contributo intende indagare i danni e le conseguenti ricostruzioni, con particolare riferimento alle tipologie edilizie e alle tecniche costruttive adottate prima e dopo il sisma. L'azione di verifica e monitoraggio delle condizioni delle fabbriche e i conseguenti interventi di consolidamento e riparazione sono efficacemente documentati in testi a stampa e nei report coevi al sisma e –soprattutto- da una copiosa documentazione archivistica. Si ident…
YTTRIUM AND REE SIGNATURE RECOGNIZED IN CENTRAL MEDITERRANEAN SEA (ODP SITE 963) DURING THE MIS 6 – MIS 5 TRANSITION
2010
The Mediterranean Sea acts as a miniature ocean with the development of its own conveyor belt. It constitutes an ideal location to study and forecast how the marine environment responds to rapid climatic change. Here we present a palaeoenvironmental study carried out on the sediments of ODP Site 963, recovered in the Sicily Channel, the sill which divides the western from the eastern Mediterranean basin. We focused on the transition between the penultimate glacial (MIS 6) and the last interglacial (MIS 5), between approximately 130 and 115 kyr BP. A novel approach is proposed, taking into account centennial-scale geochemical data on major elements, selected trace elements, and yttrium and R…
Środowiska polskiej emigracji politycznej wobec odbudowy Zamku Królewskiego w Warszawie
2017
20 stycznia 1971 r. I sekretarz KC PZPR Edward Gierek podczas spotkania z przedstawicielami środowisk twórczych zapowiedział odbudowę Zamku Królewskiego w Warszawie. W Polsce decyzja o odbudowie przyjęta została z entuzjazmem i wyzwoliła wielką ofiarność społeczną. Odbudowa Zamku zapowiedziana przez nowego przywódcę partii komunistycznej wywołała jednak żarliwe dyskusje i spory w kręgach polonijnych. Znaczna część emigracji, zwłaszcza wywodząca się z politycznych elit, nie negując sensu i potrzeby odbudowy Zamku, jednego z symboli niepodległej Polski, dopatrywała się jednak koniunkturalnego i instrumentalnego charakteru decyzji władz PRL. Sprzeciw wywoływała szczególnie planowana zbiórka pi…
Toward a virtual reconstruction of an antique three-dimensional marble puzzle
2017
International audience; Abstract | Introduction | Related Work | Acquisition Setup, Proposed Prototype: Calibration and Visibility | Preprocessing of Scanned Three-Dimensional Fragment Data | Processing of Scanned Three-Dimensional Surface Data: Matching | Conclusion and Future Works | Appendices | Acknowledgments | ReferencesAbstract. The reconstruction of broken objects is an important field of research for many applications, such as art restoration, surgery, forensics, and solving puzzles. In archaeology, the reconstruction of broken artifacts is a very time-consuming task due to the handling of fractured objects, which are generally fragile. However, it can now be supported by three-dim…