Search results for "performance"
showing 10 items of 4457 documents
Investigation of design strategies and quantification of energy flexibility in buildings: A case-study in southern Italy
2021
Abstract The need for nearly (net) zero energy buildings in the current European landscape does not merely refer to energy balances: the aim to investigate the interaction between generation and load and find sources of technical-economic energy efficiency is marking the rise in interest throughout research and practice of energy flexibility solutions in buildings. In this regard, the study aims at enhancing the energy flexibility of a building in southern Italy through Rule-Based Control algorithms for the control of the space heating system and the charge and discharge of an electricity storage. The influence of electricity pricing and the thermal comfort conditions on flexibility is also…
Simultaneous enzymatic determination of l(−) malic acid and l(+) lactic acid in wine by flow injection analysis
1991
Abstract A simultaneous determination of two organic acid species in wine by a flow injection analysis method using enzyme-immobilized open tubular reactors is described. The design of the optimal geometry of the FIA system is especially important to avoid the matrix fluorescence. Reproducible results were obtained in the determination of l (−) malic acid and l (+) lactic acid using l -MDH and l -LDH, respectively. The assay reactions utilize the fluorimetric determination of a common product, NADH. The sample was dialyzed on line and injected into the FIA-system. The system responds linearly (log-log calibration graphs) to the injected sample (80 μl) in concentrations ranging from 0·1 m m …
Constructal law optimization of a boiler
2017
The paper aims at the optimization of the design of a biomass boiler under the inspiration of the Constructal Law by Bejan. The boiler is of the smoke tubes typology, fuel being biomass pellets. The smoke tubes are 16 and are placed in a staggered configuration. A model is built in MATLAB environment, based on empirical correlations and the mean log temperature methodology. The analysis is based on the development of a wide parametric analysis that involves variations of diameters, numbers and positioning of the tubes. Results are based on the concept of the overall performance coefficient methodology and investigate both the pressure drops variation and the thermal power generated in the d…
A Constructal Law optimization of a boiler inspired by Life Cycle thinking
2018
Abstract The aim of the paper is to explore how design optimization contributes to a technology's ecological evolution. The article develops this concept through an application of Constructal Law, used to account for the “evolution” of technologies design (configuration, shape, structure, pattern, rhythm), and Life Cycle Assessment (LCA), used for quantifying the environmental impacts of the design choices. The combination of both methods assesses how technology evolution affects the environment during its life, extending the concept of evolution of design. The study is applied to a case study of a real biomass boiler. The study analyses basic case and a series of alternative scenarios opti…
An evaluation of solid phase microextraction for aliphatic amines using derivatization with 9-fluorenylmethyl chloroformate and liquid chromatography
2005
The reliability of SPME combined with a chemical reaction for the analysis of short-chain aliphatic amines by liquid chromatography has been investigated. Different options to couple SPME and derivatization have been tested and compared: (i) derivatization of the analytes in solution followed by the extraction of the derivatives, (ii) extraction of the analytes and subsequent derivatization by immersing the SPME fibre onto a solution of the reagent, and (iii) extraction/derivatization of the analytes using fibres previously coated with the reagent. Methylamine (MA), dimethylamine (DMA) and trimethylamine (TMA) have been selected as a model of primary, secondary and tertiary amines, respecti…
Analysis of 18 perfluorinated compounds in river waters: Comparison of high performance liquid chromatography–tandem mass spectrometry, ultra-high-pe…
2012
In this work, the performance of ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and capillary liquid chromatography-mass spectrometry (CLC-MS) has been studied for the analysis of eighteen perfluorinated compounds in water samples. UHPLC-MS/MS and CLC-MS analysis were carried out using a Zorbax C-18 column (50 mm × 2.1 mm, 1.8 μm) and a Zorbax SB-C18 column (150 mm × 0.5 mm, 3.5 μm), respectively, in gradient elution mode with a mobile phase of ammonium formate and methanol. Both techniques were compared with conventional LC-MS/MS in terms of speed, sensitivity, selectivity and resolution. Water samples were extracted by solid phase extraction (SPE). Mea…
Derivatization of hydroxyl functional groups for liquid chromatography and capillary electroseparation
2013
The derivatization reactions commonly used to enhance the analytical signal in the HPLC and CE determination of compounds with hydroxyl functional groups are revised. Focus is placed on the determination of compounds having aliphatic alcohols and phenols while lacking other reactive functional groups. The derivatization with acyl chlorides, organic anhydrides, isocyanates and a variety of other approaches, including oxidation of primary and secondary alcohols, sulfonation, esterification with carboxylic acids, and the use of azides, sulfonyl chlorides and other reagents having miscellaneous leaving groups, is covered. Reactions mainly addressed to introduce a chromophore or a fluorophore in…
Energy consumption and improvement of energy efficiency for the European agricultural-food system
2020
This work addresses the subjects of reducing fossil energy consumption and the interventions to improve energy efficiency in the European agricultural-food sys-tem. Following an overview on both such subjects, the results of European projects TESLA and SCOoPE are also analysed with attention to best practices and technologies available to improve energy efficiency in order to reduce the fossil energy use in agri-food systems of Mediterranean countries. A list of Key Performance Indicators for the fruit and vegetable sector, useful for comparative analyses aimed at selecting best methods of energy management and technologies for improving energy efficiency, is reported. Finally, a brief focu…
Effect of fatigue and gender on kinematics and ground reaction forces variables in recreational runners.
2017
The presence of fatigue has been shown to modify running biomechanics. Overall in terms of gender, women are at lower risk than men for sustaining running-related injuries, although it depends on the factors taken into account. One possible reason for these differences in the injury rate and location might be the dissimilar running patterns between men and women. The purpose of this study was to determine the effect of fatigue and gender on the kinematic and ground reaction forces (GRF) parameters in recreational runners. Fifty-seven participants (28 males and 29 females) had kinematic and GRF variables measured while running at speed of 3.3 m s−1 before and after a fatigue test protocol. T…
Audit Quality and Corporate Governance: Evidence from the Microfinance Industry
2012
This study uses a unique, hand-collected sample of microfinance institutions from 73 countries that typically are not investigated in accounting research to analyze the relationships between audit quality and governance mechanisms. We examine two measures of audit quality, namely, the use of Big Four auditors and the presence of internal auditors who report to the boards of these institutions. The empirical analysis of this study reveals that these two quality metrics are highly related, although we also demonstrate that these metrics capture distinctive aspects of audit quality. In particular, the presence of internal auditors is related to other indicators of stricter governance, whereas …