Effect of α-Hgl_2 epitaxial growth on the defect structure of CdTe:Ge substrates

The aα-HgI_2/CdTe:Ce heterostructures have been studied by cathodoluminescence (CL) in the scanning electron microscope. The alpha-HgI2 expitaxial growth was shown to cause an enhancement of the CL intensity in a layer of the substrate extending up to about 500 mu m from the α-Hgl_2 /CdTe:Ge interface. CL spectra of the layer reveal the appearance of a band related to tellurium vacancies as well as the decrease of the emission attributed to defect complexes involving Ge. The data obtained indicate that Ge-impurity gettering and V-Te generation at the interface take place during α-Hgl_2 epitaxial growth

Application of cathodoluminescence microscopy to the study of native acceptors in gallium antimonide

Cathodoluminescence in the scanning electron microscope is used to ivestigate growth and prosess induced defects in GaSb crystals. In particular, luminescence emission has been used to study the nature of acceptor defects present after different annealing and irradiation treatments

Reducing scrap and improving an air conditioning pipe production line

30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) -15-18 June 2021, Athens, GreeceThe automotive industry is considered one of the most demanding and competitive sectors in the global market. This increasingly implies having a stable and optimized production process, always with a view to continuous improvement. Therefore, it is very important to be aware of all the waste that is generated in all production and logistics operations and take action to reduce them. In this regard and considering the process of producing air conditioning pipes for the automotive industry, a high scrap value was detected mainly due to soldering process. Therefore, the entire production process is analyzed in order to identify the main causes behind the high scrap value. Several Lean and quality tools are used to reduce not only the amount of scrap but also to increase the line productivity. In order to face this challenge, after elaborating the action plan and corresponding implementation, the scrap value is reduced by 12% in general, and productivity increased by 29%, 55% and 22.5% in three different references produced by the same machine. Although this solution is a bit expensive, the corresponding payback is reduced, so it can easily be applied transversally to other similar machines allowing extremely interesting gains in the short term.Andresa Baptista acknowledges the financial support of CIDEM- Research Center of Mechanical Engineering, FCT –Portuguese Foundation for the Development of Science and Technology, Ministry of Science, Technology and Higher ducation, under the Project UID/EMS/0615/2019.info:eu-repo/semantics/publishedVersio

Experimental investigation of a quantum heat engine powered by generalized measurements

Generalized measurements may allow the control of its invasiveness on the quantum system interpolating from a very weak to strong projective action. Such a measurement can fuel a quantum heat engine or extract work depending on the system-meter interaction. Here, we performed a proof-of-concept experiment using Nuclear Magnetic Resonance techniques to investigate a spin quantum heat engine driven by non-selective generalized (weak) measurements without feedback control. Our prototype of a quantum thermal device operates with a measurement protocol and a single heat bath. The protocol is composed of two non-selective measurement channels with variable measurement strengths, one dedicated to fueling the device (analogous to a hot heat source) and the other committed to work extraction. The experimental results highlight that this kind of quantum thermal device can reach unit efficiency with maximum extracted power by fine-tuning of the measurement strengths.Comment: 8 pages, 6 figure

Calculation methods of Radon-222 radiological activity for NORM plant with ventilation

A procedure is proposed to determine the radiological activity of air present in the working area of a NORM (Naturally-Occurring Radioactive Materials) plant. This NORM plant is located in the United Arab Emirates and is dedicated to the recycling of material and equipment used in oil extraction facilities. Substantial quantities of NORM waste will be present inside the enclosed plant facilities and will exhale significant amounts of Radon-222 into the working environment. The continued inhalation of this gas and its progeny has been shown to cause lung cancer. In order to reduce the concentration level of the aforementioned gas to an acceptable regulatory value, the best solution is by means of mechanical ventilation. The two calculation methods used to analysis the relationship between the ventilation rate and the degree of radioactive contamination are considered. The first being ventilation by perfect dilution, commonly employed in industrial environments with radiological contamination. The second method of analysis is by means of a CFD (Computational Fluid Dynamics) which permits a more precise calculation of the required fresh air quantity and spatial concentrations. Validation was carried out in a small experimental plant space, obtaining results reasonable approximate to those predicted by the computational analysis. The similarities and differences between the respective calculation methods and their respective fields of application are analyzed. It is concluded that for lower air change rates, less than five air changes per hour, the CFD analysis is the most appropriate method. By contrast, when using a higher rate of outside air changes in the plant, the perfect dilution method should be sufficient enough to control the presence of radon and its progeny. Both calculation methods consider the activity of radon and the activity of the most significant radioisotopes of its progeny

Air diffusion system design in large assembly halls. Case study of the Congress of Deputies parliament building, Madrid, Spain

The paper describes and analyses the air distribution solution adopted in the refurbishment of the Spanish Congress of Deputies assembly hall. A new approach is proposed for the design of displacement ventilation systems. The system performance is methodically validated both with laboratory tests, computational fluid dynamics analysis and experimental field measurements related to the environmental performance of the built environment. In assembly halls, microclimate and displacement ventilation systems, which supply air by means of floor mounted outlets, have been shown to perform adequately. In this case study floor air supply is not feasible. The solution adapted uses parapet mounted diffusers, using a confluent jet flow parallel to the floor plane above the occupied area. All the tools used to analyse the performance of this system showed that the admixing overhead supply, with ceiling return, and flowing parallel to and above the occupied zone is drawn back into the occupied zone, creating a plume effect similar to that of floor mounted displacement outlets. Thus, this confirms that the displacement effect can be accomplished using a high induction turbulent overhead supply with ceiling return. Therefore supplying air directly into the occupied zone, at or near to floor level, is not a prerequisite to achieve the desired displacement effect. This report concludes that, using the correct design parameters, as set out in this paper, the displacement ventilation effect is independent of the plane of air supply. The conclusions suggest that accepted criteria for the definition and design of displacement systems should be redefined

Effect on Irradiance of the eruption of the Cordon Caulle (Chile) at different altitudes in the Nahuel Huapi National Park (Patagonia, Argentina)

Volcanic eruptions inject ash and non-ash particles into the atmosphere, modifying regional Aerosols Optical Depth (AOD) and aerosols size distribution, which affect irradiance at the earth’s surface. In this paper, we analyze the effect of the eruption of Puyehue-Cordon Caulle (Chile) on irradiance in the area of the Nahuel Huapi National Park (NHNP) (~100 km southeast of Puyehue-Cordon Caulle), at different altitudes. In this paper we only included the results for direct and AOD obtained during field campaigns at two consecutive years, before and after the eruption. Three days presented clear skies during most of the day in 2011. Two of those days, showed AOD similar to the values in 2010. On the third days, at the lowest altitude site (804m.s.l.), AOD were near 200% larger than in 2010. The largest decreases observed, at noon, in the direct irradiance was ~30% at 380 nm and 25% at 500nm, increasing with Solar Zenith Angle (SZA). The effect was less pronounced at the site at highest altitude (1930 m.s.l.), where the AODs increase was near 90% and the direct noon irradiance decrease 10% at 380 nm and 7% at 500nm. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.Fil: Diaz, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Paladini, Alejandro Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Braile, H. G.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Deferrari, Guillermo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Vernet, María. University of California at San Diego; Estados UnidosFil: Vrsalovic, Jazmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Resistin Regulates Pituitary Lipid Metabolism and Inflammation In Vivo

The adipokine resistin is an insulin-antagonizing factor that also plays a regulatory role in inflammation, immunity, food intake, and gonadal function and also regulates growth hormone (GH) secretion in rat adenopituitary cells cultures with the adipokine. Although adipose tissue is the primary source of resistin, it is also expressed in other tissues, including the pituitary. The aim of this study is to investigate the possible action of resistin on the lipid metabolism in the pituitary gland in vivo (rats in two different nutritional status, fed and fast, treated with resistin on acute and a chronic way) and in vitro (adenopituitary cell cultures treated with the adipokine). Here, by a combination of in vivo and in vitro experimental models, we demonstrated that central acute and chronic administration of resistin enhance mRNA levels of the lipid metabolic enzymes which participated on lipolysis and moreover inhibiting mRNA levels of the lipid metabolic enzymes involved in lipogenesis. Taken together, our results demonstrate for the first time that resistin has a regulatory role on lipid metabolism in the pituitary gland providing a novel insight in relation to the mechanism by which this adipokine can participate in the integrated control of lipid metabolism