Power generation by unhealthy photovoltaic modules

Hotspots are one of many defects that can occur on degraded photovoltaic system, yielding a detrimental effect on the PV module production. Infrared thermography was used to detect and quantify the severity of hotspots. Temperature difference between overheated and healthy areas was assessed. Four PV modules were analysed, one of them presenting a hotspot. A model for both healthy and unhealthy PV modules was developed, based on the single diode solar cell model and considering, exclusively, data-sheet parameters. To validate the model, the outputs for these working conditions were compared with the real outputs of the studied PV modules, which were previously measured and stored. The relationship between the severity of a hotspot and its respective impact on the power generation of the PV module was studied and the consequent monetary loss can be assessed. Thermographic analysis was enhanced as an optimizing decision-aid tool for the operation of photovoltaic installations.publishersversionpublishe

Co‐existing monophasic teratoma and uterine adenocarcinoma in a female dog

Ovarian teratomas are occasionally reported in dogs; the rarest type is the monophasic teratoma,composed of tissues originating from only one germ layer. Canine endometrial adenocarcinomas are also rare in dogs and mainly affect geriatric females. This report describes case of co-existing ovarian teratoma and uterine adenocarcinoma in a 10-year old nulliparous female Boxer presented with lethargy, anorexia and purulent vaginal discharge. Abdominal ultrasonography evidenced pyometra and a mass in the left ovary. This was composed of a uniform whitish tissue with multiple cystic structures. The histology revealed an atrophy of the ovarian parenchyma, compressed by a proliferation of well-differentiated nervous tissue staining positively to vimentin, S100 and neuronal specific enolase (NSE), and negatively to keratin and inhibin. The left uterine horn, whose diameter was markedly increased, showed foci of endometrial cellular atypia, evident nucleoli and mitoses, at light microscopy. To our best knowledge, this is the first report of a coexisting ovarian monophasic teratoma and endometrial adenocarcinoma, two rare reproductive neoplasia in dogs

Efficient channel estimation using TCH codes

In this paper, we consider the use of TCH codes to perform channel estimation in an OFDM system, using either data multiplexed pilots or superimposed pilots over the data. TCH codes possess several properties that allow us to use them efficiently in various applications which includes channel estimation, as we address in this paper. With this objective, several performance results were obtained through simulations which allowed the evaluation of the impact of different pilot power levels and modulations, as well as the comparison of TCH against other conventional pilots. In order to cope with the interference between pilots and data, an iterative receiver with interference suppression was employed for the superimposed pilots method.info:eu-repo/semantics/acceptedVersio

Robust joint synchronization and channel estimation approach for frequency-selective environments

Supporting spontaneous low-latency machine type communications requires fast synchronization and channel estimation at the receiver. The problems of synchronizing the received frame and estimating the channel coefficients are often addressed separately with the later one relying on accurate timing acquisition. While these conventional approaches can be adequate in flat fading environments, time dispersive channels can have a negative impact on both tasks and severely degrade the performance of the receiver. To circumvent this large degradation, in this paper we consider the use of a sparse based reconstruction approach for joint timing synchronization and channel estimation by formulating the problem in a form that is closely related to Compressive Sensing(CS) framework. Using modified versions of well-known sparse reconstruction techniques, which can take into account the additional signal structure in addition to sparsity, it is shown through numerical simulations that, even with short training sequences, excellent timing synchronization and channel estimation performance can be achieved, both in single user and multiuser scenarios.info:eu-repo/semantics/publishedVersio

Angiogenesis in NSCLC: is vessel co-option the trunk that sustains the branches?

The critical role of angiogenesis in tumor development makes its inhibition a valuable new approach in therapy, rapidly making anti-angiogenesis a major focus in research. While the VEGF/VEGFR pathway is the main target of the approved anti-angiogenic molecules in NSCLC treatment, the results obtained are still modest, especially due to resistance mechanisms. Accumulating scientific data show that vessel co-option is an alternative mechanism to angiogenesis during tumor development in well-vascularized organs such as the lungs, where tumor cells highjack the existing vasculature to obtain its blood supply in a non-angiogenic fashion. This can explain the low/lack of response to current anti-angiogenic strategies. The same principle applies to lung metastases of other primary tumors. The exact mechanisms of vessel co-option need to be further elucidated, but it is known that the co-opted vessels regress by the action of Angiopoietin-2 (Ang-2), a vessel destabilizing cytokine expressed by the endothelial cells of the pre-existing mature vessels. In the absence of VEGF, vessel regression leads to tumor cell loss and hypoxia, with a subsequent switch to a neoangiogenic phenotype by the remaining tumor cells. Unravelling the vessel co-option mechanisms and involved players may be fruitful for numerous reasons, and the particularities of this form of vascularization should be carefully considered when planning anti-angiogenic interventions or designing clinical trials for this purpose. In view of the current knowledge, rationale for therapeutic approaches of dual inhibition of Ang-2 and VEGF are swiftly gaining strength and may serve as a launchpad to more successful NSCLC anti-vascular treatments.info:eu-repo/semantics/publishedVersio

Virgin olive oil as a source of anti-inflammatory agents

Virgin olive oil (VOO) has many potential health benefits, including the amelioration of inflammatory processes. In part, this is known to occur through the modification of the endothelial function, leading to a decrease of the levels of cell-adhesion molecules (CAMs), including the inter-cellular adhesion molecule 1 (ICAM-1) and the vascular cell adhesion molecule 1 (VCAM-1). Importantly, virgin olive oil is able to inhibit the tumor necrosis factor-alpha (TNF-α), that is a key cytokine in controlling distinct types of cell functions and a particular therapeutic target for inflammatory diseases. Moreover, in vitro and in vivo assays with virgin olive oil or its main components clearly indicate a marked modulation of signaling pathways regulating the activation of pro-inflammatory mediators, including the nuclear transcriptional factor NF-κβ, the cytokines interleukin-1 (IL-1), and interleukin-6 (IL-6), and the enzymes cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) and inducible nitric oxide synthase (iNOS). So far, the cellular and molecular anti-inflammatory mechanisms of virgin olive oil have been particular associated with its high amounts of phenolic compounds, as well as to its composition in mono and polyunsaturated fatty acids. Still, the available data is disperse and needs consolidation, in order to allow solid conclusions on this issue. The present chapter summarizes the epidemiological data and intervention trials focusing the effects of virgin olive oil in inflammatory processes and/or inflammatory related-diseases, as well as the main virgin olive oil constituents associated to the protection process and their underlying mechanisms of action