a model in the loop application of a predictive controller to a district heating system

Abstract The high weather variability due to climate change and the need to reduce carbon emissions require innovative solutions for energy systems and grids. In particular, improvements in control strategies allow to increase efficiency without changing the system configuration. Adaptive controllers, as currently proposed, base the management of the system on its past behavior. The main drawback of these methods is the lack of flexibility required to face the mentioned scenario. This paper presents a Model Predictive Control approach which, instead, is based on the prediction of the future evolution of the controlled system. Since it allows to consider the external conditions variability, a more resilient way to manage District Heating and Cooling networks can be achieved. The novel control strategy is developed and tested through a Model-in-the-Loop application to a thermal energy network. This latter is composed by combining physics-based dynamic models from a dedicated library of energy systems components developed by the authors in the Matlab®/Simulink® environment. The network model is controlled by the MPC controller model, which shows to be flexible and reliable in the optimization and management of energy systems

On the Sizing of the DC-Link Capacitor to Increase the Power Transfer in a Series-Series Inductive Resonant Wireless Charging Station

Wireless inductive-coupled power transfer is a very appealing technique for the battery recharge of autonomous devices like surveillance drones. The charger design mainly focuses on lightness and fast-charging to improve the drone mission times and reduce the no-flight gaps. The charger secondary circuit mounted on the drone generally consists of a full-bridge rectifier and a second-order filter. The filter cut-off frequency is usually chosen to make the rectifier output voltage constant and so that the battery is charged with continuous quantities. Previous works showed that an increase in power transfer is achieved, if compared to the traditional case, when the second-order filter resonant frequency is close to the double of the wireless charger excitation and the filter works in resonance. This work demonstrates that the condition of resonance is necessary but not sufficient to achieve the power increment. The bridge rectifier diodes must work in discontinuous-mode to improve the power transfer. The paper also investigates the dependence of the power transfer increase on the wireless excitation frequency. It is found the minimum frequency value below which the power transfer gain is not possible. This frequency transition point is calculated, and it is shown that the gain in power transfer is obtained for any battery when its equivalent circuit parameters are known. LTSpice simulations demonstrate that the transferred power can be incremented of around 30%, if compared to the case in which the rectifier works in continuous mode. This achievement is obtained by following the design recommendations proposed at the end of the paper, which trade off the gain in power transfer and the amplitude of the oscillating components of the wireless charger output

Nutritional Properties of Milk from Dairy Ewes Fed with a Diet Containing Grape Pomace

Abstract: The aim of the present study was to evaluate the effects of a diet containing a 10% of grape pomace (GP) on the milk yield, chemical-nutritional characteristics, total phenolic compounds (TPCs), antioxidant activity (AOA), fatty acids and proteins profile of dairy ewe’s milk. Forty-six ewes were dived into two groups: a control group (Ctrl), fed a standard diet, and an experimental group (GP+), whose diet was supplemented with 10% of GP on dry matter. The trial lasted 60 days and milk samples were collected and analyzed at the beginning (T0) and after 60 (T60) days. Dietary enrichment with GP did not affect the yield and the chemical composition of the milk. TPCs and AOA were not affected by the diet. After 60 days, the diet induced an increase in monounsaturated fatty acids (MUFA) and a decrease in medium chain saturated fatty acids (MCSFA), but the total saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), short chain saturated fatty acids (SCSFA) and long chain saturated fatty acids (LCSFA) were not modified. A decrease in the C14 desaturation index and an increase in the C18 index were also detected. Total caseins and whey protein were not affected by GP, even if a lower content of k-casein in GP+ milk compared to Ctrl milk was observed on the 60th day. The results of the present study suggest that 10% of GP can be included in the diet of lactating ewes without modifying milk gross composition but inducing significantly changes the fatty acid profile

Temporal changes in blood-brain barrier permeability and cerebral perfusion in lacunar/subcortical ischemic stroke

BACKGROUND: Cerebral microvascular abnormality is frequently associated with lacunar and subcortical ischemic lesions. We performed acute and follow-up CT perfusion scans over the first 3 months after ischemic stroke to investigate disturbances of the blood–brain barrier (BBB) and cerebral perfusion in patients with lacunar/subcortical lesions compared to those with cortical lesions alone. METHODS: Thirty-one patients with lacunar/subcortical infarct (n = 14) or with cortical large vessel infarct (n = 17) were recruited and underwent a CT perfusion study at admission, 24 h, 7 days and 3 months after stroke using a two-phase imaging protocol. Functional maps of BBB permeability surface area product (BBB-PS), cerebral blood flow (CBF) and blood volume (CBV) at follow-up were co-registered with those at admission, and the measurements in non-infarcted ipsilateral basal ganglia and thalamus were compared within each group and between the two groups. RESULTS: For the lacunar/subcortical group, BBB-PS within non-infarcted ipsilateral basal ganglia and thalamus peaked at day 7 compared to all other time points, and was significantly higher than the cortical group at day 7 and month 3. The CBF and CBV in the same region were significantly lower at admission and transient hyperemia was seen at day 7 in the lacunar/subcortical group. CONCLUSION: Disturbed BBB-PS and compromised cerebral perfusion over the first 3 months post stroke were shown in the non-infarcted basal ganglia and thalamus of lacunar/subcortical stroke using CT perfusion. Future studies are required to elucidate the relationship of post-stroke BBB disturbances to chronic cognitive impairment

Cross-Linked Hyaluronan Derivatives in the Delivery of Phycocyanin

An easy and viable crosslinking technology, based on the “click-chemistry” reaction copper(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (click-crosslinking), was applied to graft copolymers of medium molecular weight (i.e., 270 kDa) hyaluronic acid (HA) grafted with ferulic acid (FA) residues bearing clickable propargyl groups, as well as caffeic acid derivatives bearing azidoterminated oligo(ethylene glycol) side chains. The obtained crosslinked materials were characterized from the point of view of their structure and aggregation liability to form hydrogels in a water environment. The most promising materials showed interesting loading capability regarding the antioxidant agent phycocyanin (PC). Two novel materials complexes (namely HA(270)-FA-TEGECCL- 20/PC and HA(270)-FA-HEGEC-CL-20/PC) were obtained with a drug-to-material ratio of 1:2 (w/w). Zeta potential measurements of the new complexes (−1.23 mV for HA(270)-FA-TEGECCL- 20/PC and −1.73 mV for HA(270)-FA-HEGEC-CL-20/PC) showed alterations compared to the zeta potential values of the materials on their own, suggesting the achievement of drug–material interactions. According to the in vitro dissolution studies carried out in different conditions, novel drug delivery systems (DDSs) were obtained with a variety of characteristics depending on the desired route of administration and, consequently, on the pH of the surrounding environment, thanks to the complexation of phycocyanin with these two new crosslinked materials. Both complexes showed excellent potential for providing a controlled/prolonged release of the active pharmaceutical ingredient (API). They also increased the amount of drug that reach the target location, enabling pH-dependent release. Importantly, as demonstrated by the DPPH free radical scavenging assay, the complexation process, involving freezing and freeze-drying, showed no adverse effects on the antioxidant activity of phycocyanin. This activity was preserved in the two novel materials and followed a concentration-dependent pattern similar to pure PC

Physical, Nutritional, and Sensory Properties of Cheese Obtained from Goats Fed a Dietary Supplementation with Olive Leaves

The aim of this study is to evaluate the physical, nutritional, and sensory properties of cheese obtained from goats fed a dietary supplementation with olive leaves (OL). Thirty Saanen goats were randomly allocated into two groups of 15 goats each, (1) a control group fed with a standard diet (CG), and (2) an experimental group (EG) fed an OL-enriched diet. The trial lasted for 30 days. The milk of each group was then collected and used to produce Caciotta cheese, which was analyzed at the beginning and at the end of the ripening period (60 days). The results showed a positive effect of dietary OL supplementation in improving the fatty acid profiles due to the significant increase of unsaturated fatty acids, mostly α-linolenic acid (C18:3 n-3), with the consequent reduction of the ω-6/ω-3 ratio, a condition commonly associated with an increased health functionality of food products. Moreover, improved oxidative stability was observed in cheese during ripening, a presumable consequence of the transfer into the milk of dietary bioactive compounds, mainly polyphenols of high biological value, and credited as a marked antioxidant potential. Furthermore, reduced lipolytic action was observed in 60-day ripened cheese, even if no significant changes in sensory properties were evidenced

Cerebral blood volume ASPECTS is the best predictor of clinical outcome in acute ischemic stroke: A retrospective, combined semi-quantitative and quantitative assessment

INTRODUCTION:The capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned. METHODS:62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded. RESULTS:Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS ≤ 2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome. CONCLUSIONS:Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size

Click-Chemistry Cross-Linking of Hyaluronan Graft Copolymers

An easy and viable crosslinking procedure by click-chemistry (click-crosslinking) of hyaluronic acid (HA) was developed. In particular, the clickable propargyl groups of hyaluronane-based HA-FA-Pg graft copolymers showing low and medium molecular weight values were exploited in crosslinking by click-chemistry by using a hexa(ethylene glycol) spacer. The resulting HA-FA-HEG-CL materials showed an apparent lack of in vitro cytotoxic effects, tuneable water affinity, and rheological properties according to the crosslinking degree that suggests their applicability in different biomedical fields

GEN-O-MA project: an Italian network studying clinical course and pathogenic pathways of moyamoya disease—study protocol and preliminary results

Background: GENetics of mOyaMoyA (GEN-O-MA) project is a multicenter observational study implemented in Italy aimed at creating a network of centers involved in moyamoya angiopathy (MA) care and research and at collecting a large series and bio-repository of MA patients, finally aimed at describing the disease phenotype and clinical course as well as at identifying biological or cellular markers for disease progression. The present paper resumes the most important study methodological issues and preliminary results. Methods: Nineteen centers are participating to the study. Patients with both bilateral and unilateral radiologically defined MA are included in the study. For each patient, detailed demographic and clinical as well as neuroimaging data are being collected. When available, biological samples (blood, DNA, CSF, middle cerebral artery samples) are being also collected for biological and cellular studies. Results: Ninety-eight patients (age of onset mean ± SD 35.5 ± 19.6 years; 68.4% females) have been collected so far. 65.3% of patients presented ischemic (50%) and haemorrhagic (15.3%) stroke. A higher female predominance concomitantly with a similar age of onset and clinical features to what was reported in previous studies on Western patients has been confirmed. Conclusion: An accurate and detailed clinical and neuroimaging classification represents the best strategy to provide the characterization of the disease phenotype and clinical course. The collection of a large number of biological samples will permit the identification of biological markers and genetic factors associated with the disease susceptibility in Italy

Angioplasty in acute middle cerebral artery stroke due to atrial fibrillation selected by CT perfusion: a case report

We report the experience of a case of acute stroke in a patient affected by Rendu Osler syndrome and atrial fibrillation. The combination of dynamic computerized tomography perfusion scans and the use of a high-compliance balloon allowed increasing the treatment window for intra-arterial recanalization over 6 h after stroke onset in a patient with middle cerebral artery occlusion