A new coupling solution for G3-PLC employment in MV smart grids

This paper proposes a new coupling solution for transmitting narrowband multicarrier power line communication (PLC) signals over medium voltage (MV) power lines. The proposed system is based on an innovative PLC coupling principle, patented by the authors, which exploits the capacitive divider embedded in voltage detecting systems (VDS) already installed inside the MV switchboard. Thus, no dedicated couplers have to be installed and no switchboard modifications or energy interruptions are needed. This allows a significant cost reduction of MV PLC implementation. A first prototype of the proposed coupling system was presented in previous papers: it had a 15 kHz bandwidth useful to couple single carrier PSK modulated PLC signals with a center frequency from 50–200 kHz. In this paper, a new prototype is developed with a larger bandwidth, up to 164 kHz, thus allowing to couple multicarrier G3-PLC signals using orthogonal frequency division multiplexing (OFDM) digital modulation. This modulation ensures a more robust communication even in harsh power line channels. In the paper, the new coupling system design is described in detail. A new procedure is presented for tuning the coupling system parameters at first installation in a generic MV switchboard. Finally, laboratory and in-field experimental test results are reported and discussed. The coupling performances are evaluated measuring the throughput and success rate in the case of both 18 and 36 subcarriers, in one of the different tone masks standardized for the FCC-above CENELEC band (that is, from 154.6875–487.5 kHz). The experimental results show an efficient behavior of the proposed coupler allowing a two-way communication of G3-PLC OFDM signals on MV networks

ANAEROBIC DIGESTION AS CENTRE OF DAIRY LIVESTOCK AND AGRICULTURE INTEGRATION: BASIS FOR MEDIUM-SCALE CDM PROJECTS DEVELOPMENT

Dairy producers should improve their activity with modern production techniques/technologies to meet the requirements of a stricter consumer market. In this sense, crop and livestock systems integration represents an interesting alternative for using the dairy farm available resources. This paper analyses the use of anaerobic digestion as basis for supplying energy, fertilizers and feed needs of a farming unit, by means of digestion products usage: biogas, which can be used in energy conversion systems to provide the required energy for processing/conservation equipment for milk and other farming products; and effluent, that can be used as a replacement for chemical fertilizers and for aquatic plants/fish feeding. Fossil fuels replacement by biogas can be classified as a Clean Development Mechanism (CDM) project, and economic resources obtained by carbon credits commercialisation may support the required production modernisation. The paper analyses the anaerobic digestion process, evaluating biogas in medium-scale dairy farms, as well as the quantification of carbon credits generated by introducing proper manure and culture remains management

EXPERIMENTAL VALIDATION OF A CAPPILARY TUBE SIMULATION MODEL WITH REFRIGERANT MIXTURES FLOW

This paper presents the experimental validation of a simulation model for refrigerant mixtures flow through capillary tubes. To perform such validation it was built an experimental apparatus using a blow-down process. It was carried out preliminary tests for characterization of experimental parameters: actual capillary tube diameters; relative roughness; and the heat losses in subcooling/quality control system. It was obtained almost 200 experimental points for R-407C (a zeotropic mixture) and R-410A (a near azeotropic mixture). Complete data set for each point consists of the measured pressure and temperature profiles, mass flow rate and mixture composition, as well as subcooling/quality control system inlet and outlet temperatures and heater electric power consumption for tests with two-phase flow capillary tube inlet conditions. Comparison of simulation and experimental data show a good agreement. Main deviations are connected with the delay of vaporization phenomenon occurrence, experimentally verified by the authors

BIOCHEMICAL AND FUNCTIONAL PROFILE OF SPONTANEOUSLY DIFFERENTIATED HUMAN MONOCYTE-DERIVED MACROPHAGES IN PATIENTS WITH ISCHEMIC HEART DISEASE

Background: Atherosclerosis is a chronic inflammatory disease in which oxidative stress and macrophages play fundamental roles. Macrophages are heterogeneous cells in term of morphology and function and the prevalence of a specific morpho-phenotype may influence the progression or the regression of the plaque. Human coronary plaque macrophages are not easily obtainable and monocyte-derived macrophages (MDMs) are widely accepted as a good surrogate. Our previous study has reported that healthy subjects show two dominant MDM morphotypes, spindle and round, present in the same percentage. Aim: The aims of the study were to assess the biochemical and functional profile of MDMs obtained from CAD patients and to investigate the relationship between these characteristics and plaque features detected in vivo. Material and methods: ninety CAD patients and twenty-five healthy volunteers were enrolled. MDMs were obtained by culturing monocytes for 7 days in medium supplemented with 10% autologous serum. Transglutaminase2 (TG2), tissue factor (TF), nuclear factor erythroid 2\u2013related factor 2 (Nrf2) and heme-oxygenase (HO-1) were determined by western blotting and immunofluorescence. The uptake of apoptotic Jurkat T cells was detected by flow cytometry and thrombin formation was assessed by thrombinoscope. Fatty acids composition and oxidative stress status, determined as the ratio between the reduced and oxidized forms of glutathione (GSH and GSSG, respectively) were analyzed by liquid-chromatography tandem mass spectrometry (LC-MS/MS). Plaque features were detected in vivo by optical coherence tomography (OCT). Results: MDMs obtained from CAD patients were characterized by the predominance of round cells. These cells exhibited a lower efferocytic capacity and higher capacity to generate thrombin in respect to those of healthy subjects, reflecting the low expression of TG2 and the enhance of TF levels. Moreover, MDMs of CAD patients showed a higher oxidative stress status, evidenced by the lower GSH/GSSG ratio, in respect to those of healthy subjects. Finally, we found a positive correlation between oxidative stress status and membrane fluidity (MFI) as evidenced by the ratio of C18:1 (oleic acid)/C18:2 (linoleic acid), as well as MFI and capacity to engulf apoptotic cells. Regarding OCT analysis, patients with a higher round MDMs prevalence exhibited more frequently a lipid rich plaque, a TCFA (thin cap fibroatheroma), a greater intra-plaque macrophage content, and a ruptured plaque, characteristics of vulnerable plaque. Furthermore, patients with high TF levels more frequently presented a intra-plaque macrophages accumulation, a ruptured plaque and a presence of thrombus. In addition, vulnerable plaque characteristics were associated with high HO-1 levels. Conclusions: MDMs of CAD patients present a pro-inflammatory and high thrombogenic profile in respect to those of healthy volunteers. The high oxidative stress present in these cells influences the membrane fluidity that in turn influences the efferocytic capability. This specific cellular profile detected in in vitro obtained MDMs is associated with the detection of high-risk and rupture-prone coronary plaques in vivo, at OCT investigation. Different MDM phenotypes might be novel diagnostic and therapeutic target able to counteract the progression of atherosclerosis

Negative-pressure pulmonary edema presented with concomitant spontaneous pneumomediastinum: Moore meets Macklin

Negative-pressure pulmonary edema is an unusual complication mainly associated with general anesthesia. It is caused by excessive negative intrathoracic pressure following a deep inspiration against an acute airway obstruction. The resultant decreased intrathoracic pressure amplifies venous return to the right heart and increases pulmonary capillary wedge pressure that can be further amplified by massive sympathetic discharge due to hypoxia. The combination of increased venous return and pulmonary capillary wedge pressure favours the shift of fluid into the pulmonary interstitium with resultant pulmonary edema. Conversely, spontaneous pneumomediastinum (SP) results from alveolar rupture following an excessive positive intrathoracic pressure. The air leaks out of the alveoli and along the perivascular space toward the mediastinum. We experienced a case of negative pulmonary edema which presented in association with SP. Pneumomediastinum is probably caused by an excessive positive intrathoracic pressure for a subsequent expiration against a closed airway. In the present case, both complications resolved with conservative management

FEASIBILITY OF A BRAYTON CYCLE AUTOMOTIVE AIR CONDITIONING SYSTEM

The goal of this work is to develop a preliminary analysis on the feasibility of using an alternative automotive air conditioning system based on the Brayton cycle, to be assembled using a turbocompression-intercooling system configuration available in the market. The first step of the analysis was a thermodynamic study to define the system capacity and parameters for selecting the system components. The next step was to select from turbocompressor maps a suitable model for the application, and to determine pressures/temperatures throughout the system in order to evaluate intercooler capacity and select a suitable model available in the market. The impact of the turbocompression system was also analyzed in engine performance. The proposed turbocompression system requires 1,7 kW from the engine, which is very similar to a conventional air conditioning system requirement. In terms of weight, this preliminary analysis indicated that the proposed system is about 1,0 kg heavier than the conventional system. The analysis indicated that the alternative system is about 56% more expensive than the conventional one, but on the other hand presents a 24% lower maintenance cost . Considering the results of the preliminary analysis, the proposed system is technically feasible for application in automotive air conditioning, but requires a design optimization process in order to reduce its weight and initial costs, which might allow lower maintenance costs to payback the alternative system

Iron and liver diseases.

A mild to moderate iron excess is found in patients with liver diseases apparently unrelated to genetic hemochromatosis. Iron appears to affect the natural history of hepatitis C virus-related chronic liver diseases, alcoholic liver disease and nonalcoholic steatohepatitis by leading to a more severe fibrosis and thus aiding the evolution to cirrhosis.Ahigher frequency of mutations of the HFE gene, the gene responsible for hereditary hemochromatosis, is found in patients with liver diseases and increased liver iron than in normal patients. Patients with excess iron are potentially at a higher risk of developing hepatocellular carcinoma. Iron depletion therapy could interfere with fibrosis development and possibly reduce the risk of liver cancer occurrence

Managing benign tracheal stenosis during COVID-19 outbreak

If elective surgery has been recommended to be postponed some diseases could potentially become life-threatening and cannot be delayed. Among these conditions, tracheal idiopathic stenosis, primary caused by endotracheal intubation or tracheostomy, usually become symptomatic when reach 50% obstruction. Endoscopic procedures could be considered as frst treatment in selected patients after stenosis evaluation, such as non-complex stenosis with low grade of cartilage involvement or tracheomalaci

Reconstruction with a pectoralis major myocutaneous flap after left first rib and clavicular chest wall resection for a metastasis from laryngeal cancer

We presented a case of recurrent metastasis from epidermoid cancer that occurred in the left clavicle of a patient with a history of laryngeal cancer treated on April 2005 with extended hemilaryngectomy, neck dissection and chemoradiation therapy. On September 2008, he developed a left clavicular metastasis. The disease was initially well controlled by chemoradiotherapy but it recurred 17 months later. The optimal treatment plan was established by several multidisciplinary meetings and the patient subsequently underwent an en bloc resection of the left clavicle, first rib and all the other involved structures. Coverage of the thoracic defect was achieved using pectoralis major myocutaneous flap. The patient had a successful surgical outcome. At 1-year follow-up, he had no evidence of disease, a good cosmetic result and returned to normal daily activity. He died for bone metastasis with an overall 21 months post-surgical survival.We presented a case of recurrent metastasis from epidermoid cancer that occurred in the left clavicle of a patient with a history of laryngeal cancer treated on April 2005 with extended hemilaryngectomy, neck dissection and chemoradiation therapy. On September 2008, he developed a left clavicular metastasis. The disease was initially well controlled by chemoradiotherapy but it recurred 17 months later. The optimal treatment plan was established by several multidisciplinary meetings and the patient subsequently underwent an en bloc resection of the left clavicle, first rib and all the other involved structures. Coverage of the thoracic defect was achieved using pectoralis major myocutaneous flap. The patient had a successful surgical outcome. At 1-year follow-up, he had no evidence of disease, a good cosmetic result and returned to normal daily activity. He died for bone metastasis with an overall 21 months post-surgical survival