652 research outputs found
Advanced Exergy Analysis in the Dynamic Framework for Assessing Building Thermal Systems
This work applies the Dynamic Advanced Exergy Analysis (DAEA) to a heating and domestic hot water (DHW) facility supplied by a Stirling engine and a condensing boiler. For the first time, an advanced exergy analysis using dynamic conditions is applied to a building energy system. DAEA provides insights on the components’ exergy destruction (ED) by distinguishing the inefficiencies that can be prevented by improving the quality (avoidable ED) and the ones constrained because of technical limitations (unavoidable ED). ED is related to the inherent inefficiencies of the considered element (endogenous ED) and those coming from the interconnections (exogenous ED). That information cannot be obtained by any other approach. A dynamic calculation within the experimental facility has been performed after a component characterization driven by a new grey-box modelling technique, through TRNSYS and MATLAB. Novel solutions and terms of ED are assessed for the rational implementation of the DAEA in building energy installations. The influence of each component and their interconnections are valuated in terms of exergy destruction for further diagnosis and optimization purposes.BMWi, 03ET1218B, Anwendung exergiebasierter Methoden zur Verbesserung von Gebäudeenergiesysteme
Altered pituitary hormone secretion in male rats exposed to Bisphenol A
Bisphenol A (BPA) is a xenobiotic estrogenic compound. This compound has been suspected to have estrogenic effects on reproductive system of males and females. In this present study we investigated possible low-dose effects of BPAon Luteinizing Hormone in rats. Male Wistar rats (12-13 weeks old) were administrated a daily intra peritoneal 10 μg/kgbw/day, 50 μg/kgbw/day, 100 μg/kgbw/ day dose of BPA for 6, 6, and 12 days, and one day after last injection, serum level of Luteinizing Hormone was examined by ELISA method. All data were expressed as means ± SE. Two-way ANOVA was performed. Analysis of data showed that in all dose groups, plasma level of Luteinizing Hormone significantly decreased compared to control group. The present study showed that BPA at low doses affects Luteinizing Hormone, one of main hormones in spermatogenesis in the adult Wistar rats, and subsequently alters the steroidgenesis in testicular Leydig cells
The Serum Lead level in Patients With Retained Lead Pellets
Background: Patients, who survived from shotgun injuries, often have some retained lead pellets in their bodies. Several cases of lead toxicity have been reported regarding these patients.
Objectives: This study seeks to compare the serum lead level in patients who have retained lead pellets in their bodies with the control group.
Patients and Methods: In this case-control study, we gathered the serum lead levels of 25 patients with some retained lead pellets in their bodies due to shotgun and 25 volunteers without similar lead exposure and compared them in view of the age, gender, and living place.
Results: While the mean serum lead level in both groups was lower than the standard level (i.e. 40 µg/dL) , the mean ± SD of serum lead level were 29 ± 12.8 µg/dL and 25.3 ± 6.4 µg/dL in the case and control groups, respectively without any significant difference (P = 0. 30) . However, a positive relationship was seen between serum lead level, and the number of retained lead pellets (r = 0.447, P = 0. 025) .
Conclusions: Although extensive surgery to remove the lead pellets is not recommended in patients injured with shotguns, those with many retained lead pellets in their bodies should be considered at risk for lead poisoning and monitored carefully
Selection of native Tunisian microalgae for simultaneous wastewater treatment and biofuel production
This paper focuses on the selection of native microalgae strains suitable for wastewater treatment and biofuel production. Four Chlorophyceae strains were isolated from North-eastern Tunisia. Their performances were compared in continuous mode at a 0.3 1/day dilution rate. The biomass productivity and nutrient removal capacity of each microalgae strain were studied. The most efficient strain was identified as Scenedesmus sp. and experiments at different dilution rates from 0.2 to 0.8 1/day were carried out. Maximal biomass productivity of 0.92 g/L·day was obtained at 0.6 1/day. The removal of chemical oxygen demand (COD), ammonium and phosphorus was in the range of 92-94%, 61-99% and 93-99%, respectively. Carbohydrates were the major biomass fraction followed by lipids and then proteins. The saponifiable fatty acid content was in the 4.9-13.2% dry biomass range, with more than 50% of total fatty acids being composed of saturated and monosaturated fatty acids
Le secteur caprin laitier andalou : Stratégies de recherche, développement et formation afin d’augmenter la valeur ajoutée des fromages artisanaux
Résumé. Le secteur caprin laitier andalou produit 50% du lait de l’Espagne et possède des opportunités
de développement très claires utilisant des races autochtones et des grandes surfaces de pâturages
disponibles. La production de fromages de chèvre en Andalousie peut être considérée comme un modèle
de développement rural durable. Différents organismes publics et privés ont créé récemment un réseau de
travail multidisciplinaire pour travailler sur la promotion et le développement des fromages artisanaux
andalous, en établissant des stratégies de recherche, de développement et de formation destinées à la
valorisation de ces fromages, spécialement ceux de chèvre. A partir des résultats d’une analyse
stratégique, le présent travail propose des activités de recherche, de développement et de formation
consacrées à la caractérisation de la qualité des fromages artisanaux, aux études de marché sur la
connaissance et la perception de la qualité, aux activités de formation spécialisée dans la fromagerie et
aux activités de promotion.Abstract. The Andalusian dairy goat sector (representing 50% of the national goat milk production) has
potential opportunities for development using autochthonous breeds and semi-extensive production
systems. Goat cheese production in Andalusia can be considered as a model for a sustainable rural
development. Public institutions of research, development, and training as well as private ones have
recently created a multidisciplinary and multinstitutional network to perform actions in favour of the
marketing and promotion of the andalusian goat cheeses. In this paper, through the results of a strategic
analysis, some research, development, and training actions were proposed. These actions are related with
the improvement of quality, and the definition of the hand made cheese attributes; studies on the demand
side, and consumer perception of quality; and those related to training and promotion
Treatment and reutilization of effluents: one Mediterranean project
The problematic of effluent treatment from olive oil industry as been the subject of an European Commission funded project (INCO-MED programme): “Mediterranean Usage of Biotechnological Treated effluent Water”. The potential that effluent offers to increase the availability of water, in mediterranean regions, was the final goal of the project, co-ordinated by INETI with partners from EU and MPC. In the project different systems for the treatment of this effluent had been studied: reactors systems (Intensive type) based on the jet-loop principle (JACTO) and an anaerobic UASB hybrid type reactor technology; lagoons (extensive type) for municipal wastewater treatment were also applied. The aerobic JACTO system demonstrated high unit capacity for biological conversion and operation at different loadings, allowing the removal of the pollutant organic load and the toxicity associated with this effluent. The use of this type of reactor for pre-treatment of OOWW prior to disposal on a lagoon system was tested at FSS (Morocco). Use of fungi as a pre-treatment was tested by UNITUS (Italy), EBC (Turkey) and CBS (Tunisia). In this way the effluent could be “improved” as demonstrated in the case of anaerobic digestion and biogas production (CBS). Effluent improvement and enrichment with phosphate was also tested by UNITUS. Analytical monitoring methodologies were developed at IA (Spain) and treated effluents were tested for a number of agricultural applications in different countries. The different alternatives studied will be analysed and compared taking account of technological and socio-economical criteria in relation with the project objectives
Polyphenols content, antioxidant and antimicrobial activities of extracts of some wild plants collected from the south of Tunisia
25 wild plants were collected from the south of Tunisia. The dried aerial parts were extracted under a continuous reflux set-up in a Soxhlet extractor with hexane, ethyl acetate, methanol and water. The extracts were screened for total phenolic content, antioxidant and antimicrobial activities. Total phenolic contents were determined using a spectrophotometric technique, based on the Folin-Ciocalteau reagent and calculated as pyrogallol equivalents (PyE) per 100 g of dry weight (dw). Total phenolic content ranged from traces to 2225 ± 267 mg PyE/100 g dw in Periploca angustifolia hexane extract and Erodium glaucophyllum methanol extract, respectively. Total flavonoids and flavonols weremeasured by a colorimetric assay and expressed as mg of rutin equivalents (RuE) per 100 g dw and mg of quercetin equivalents (QuE) per 100 g dw respectively. The highest amounts of flavonoids of 315 mgRuE/100 g dw and of flavonols of 63 mg QuE/100 g dw was recorded in the ethyl acetate extract of Acacia radiana. The antioxidant capacity of all extracts was evaluated with the (1,1-diphenyl-2-picrylhydrazyl, DPPH and 2,2'-azino-bis [3-ethylbenzthiazoline-6-sulphonic acid]) ABTS tests. Several extracts showed antioxidant capacity higher than (butylated hydroxytoluene) BHT. Different trend was observed for each antioxidant system with respect to solvents used. All tested plants showedantimicrobial activity, but this activity depended closely on the nature of the solvent used and of the microorganism tested. Rhanterium suaveolens ethyl acetate extract showed the largest spectre of antibacterial activity and Bassia indica ethyl acetate extract showed the highest antifungal activity.Interestingly, some of the collected plants had a high phenolic content and powerful antioxidant and antimicrobial activities. These plants may serve as sources of antioxidants with new chemotypes and potential beneficial health properties
Numerical Modeling of Hydraulic Confinement around Crude Oil Storage Cavern in Fractured Rocks: Direct Application of DFN Concept
Unlined rock caverns for hydrocarbon storage are mainly excavated in strong and stable rock masses with very low-permeable matrix, where hydrocarbon migration is only possible along fractures connected to the cavern boundaries and their networks. In this paper, the hydraulic confinement around a URC cavern was simulated by directly applying distinct fracture network (DFN) model. First, a computational code, so-called “FNETF”, was developed to generate DFN and solving fluid flow equation along fractures. Proper internal hydraulic boundary condition of water-hydrocarbon interface at cavern boundary was defined based on the fluids properties and applied in the FNETF code. Fluid flow in fracture network was numerically simulated for different outer boundary hydraulic conditions assigned by different groundwater pressures of water curtain. Finally, the assessment achieved to expect the occurrence of hydrocarbon
Theoretical and practical convergence of a self-adaptive penalty algorithm for constrained global optimization
This paper proposes a self-adaptive penalty function and presents a penalty-based algorithm for solving nonsmooth and nonconvex constrained optimization problems. We prove that the general constrained optimization problem is equivalent to a bound constrained problem in the sense that they have the same global solutions. The global minimizer of the penalty function subject to a set of bound constraints may be obtained by a population-based meta-heuristic. Further, a hybrid self-adaptive penalty firefly algorithm, with a local intensification search, is designed, and its convergence analysis is established. The numerical experiments and a comparison with other penalty-based approaches show the effectiveness of the new self-adaptive penalty algorithm in solving constrained global optimization problems.The authors would like to thank the referees, the Associate Editor
and the Editor-in-Chief for their valuable comments and suggestions to improve the paper.
This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT
- Funda¸c˜ao para a Ciˆencia e Tecnologia within the projects UID/CEC/00319/2013 and
UID/MAT/00013/2013.info:eu-repo/semantics/publishedVersio
A critical review on polydopamine surface-modified scaffolds in musculoskeletal regeneration
Increasing concern about age-related diseases, particularly musculoskeletal injuries and orthopedic conditions, highlights the need for strategies such as tissue engineering to address them. Surface modification has been developed to create pro-healing interfaces, personalize scaffolds and provide novel medicines. Polydopamine, a mussel-inspired adhesive polymer with highly reactive functional groups that adhere to nearly all substrates, has gained attention in surface modification strategies for biomaterials. Polydopamine was primarily developed to modify surfaces, but its effectiveness has opened up promising approaches for further applications in bioengineering as carriers and nanoparticles. This review focuses on the recent discoveries of the role of polydopamine as a surface coating material, with focus on the properties that make it suitable for tackling musculoskeletal disorders. We report the evolution of using it in research, and discuss papers involving the progress of this field. The current research on the role of polydopamine in bone, cartilage, muscle, nerve, and tendon regeneration is discussed, thus giving comprehensive overview about the function of polydopamine both in-vitro and in-vivo. Finally, the report concludes presenting the critical challenges that must be addressed for the clinical translation of this biomaterial while exploring future perspectives and research opportunities in this area
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