Search results for "renewable"
showing 10 items of 2395 documents
Update on desiccant wheel model
2004
This short communication presents the update on the desiccant wheel models, developed earlier by the present authors. It is to be mentioned here that the psycrometric model presented earlier (Int. J. Energy Res., 2003; 27:17) is valid only for the desiccant wheel running with identical volume air-flows in supply and regeneration sides. However, when system runs with volume air flow ratio between supply and regeneration side (α), different from 1 (one), the model need further modifications. In the present work, correction factors were developed and incorporated in order to update the earlier model for predicting correctly the temperature and humidity of processed air at the outlet of desicca…
The Evaluation of Energy Performances of a Net Zero Energy Building: An Italian Case Study
2010
Over the past decades the impact of construction on the primary energy consumption and greenhouse gas emissions has highlighted [1]. The interest of the international scientific community has therefore focused on the concept of a Net Zero Energy Solar Building (NZESB), which is generally defined as a building that produces all primary energy it needs during a year [2]. Among the many research activities focused on these buildings, it should be mentioned the case study developed within the IEA SHC Task 40/ECBS Annex 52 "Towards Net Zero Energy Solar Buildings". The paper shows a case study of a Net Zero Energy Building (NZEB) located in Ancona (Italy):“Life Energy And Future (Leaf) House” (L…
The contribution of geographical certification programs to farm income and rural economies: The case of Pecorino Siciliano PDO
2021
This study attempts to measure the capacity of the EU geographical certification scheme to positively influence the price of certified products and the incomes of their producers. A comparison of the economic results of two cheese-producing dairy farm enterprises with different business strategies and locations within the Sicilian hinterlands is performed in order to determine the transformation value of each dairy’s sheep milk into pecorino cheese (with and without the Protected Designation of Origin, or PDO, certification) and the related joint products (ricotta). The economic convenience of the total transformation of sheep milk into Pecorino Siciliano PDO and ricotta is also appraised. …
An experimental investigation on the poor hydrogen sorption properties of nano-structured LaNi5 prepared by ball-milling
2011
Abstract Nano-structured LaNi5 hydrogen storage materials prepared by ball-milling is analysed using differential scanning calorimetry (DSC) and x-ray photoelectron spectroscopy (XPS). DSC results indicate a partial elimination of defects at 500 °C in a more efficient way for the short-time ball-milled powders compared to the long-time ball-milled ones. XPS results show almost no change in the core-level electronic structure for La and Ni of LaNi5 in the bulk and the nano-structured forms, but gives an indication that the self-restoring mechanism of the active surface observed in the bulk sample (Siegmann et al. Phys. Rev. Lett. 40, 972) may not be occurring in the nano-powders. Results fro…
Low-Q peak in X-ray patterns of choline-phenylalanine and homophenylalanine: a combined effect of chain and stacking
2016
Abstract In this contribution we report for the first time the X-ray patterns of choline-phenylalanine and choline-homophenylalanine ionic liquids. The presence of a low Q peak in both systems is another evidence that a long alkyl chain is not always needed to establish a nanodomain segregation in the liquid sufficient to be revealed by the diffraction experiment. These new data are compared with the diffraction patterns and the theoretical calculations of other choline-aminoacid ionic liquids recently reported. A significant role might be played by the stacking interactions between aromatic rings.
SPS-assisted preparation of the Magnéli phase WO2.90 for thermoelectric applications
2013
We describe the preparation and simultaneous consolidation of WO2.90 by spark plasma sintering (SPS). SPS allows for the direct manufacturing of large amounts of consolidated material. Synchrotron powder X-ray diffraction indicates that the material is single phase. Microstructure analysis indicates that the pellet is fully dense, allowing high-temperature thermoelectric properties to be reliably measured. The as-prepared samples of WO2.90 reach a ZT of 0.1 at 1100 K.
Investigation of AC Electrical Properties of MXene-PCL Nanocomposites for Application in Small and Medium Power Generation
2021
The paper examined Ti3C2Tx MXene (T—OH, Cl or F), which is prepared by etching a layered ternary carbide Ti3AlC2 (312 MAX-phase) precursor and deposited on a polycaprolactone (PCL) electrospun membrane (MXene-PCL nanocomposite). X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM) indicates that the obtained material is pure Ti3C2 MXene. SEM of the PCL-MXene composite demonstrate random Ti3C2 distribution over the nanoporous membrane. Results of capacitance, inductance, and phase shift angle studies of the MXene-PCL nanocomposite are presented. It was found that the frequency dependence of the capacitance exhibited a clear sharp minima in the frequency range of 50 Hz to o…
A simple model for computing diffuse solar radiation
1989
In this paper a very simple model for predicting the daily diffuse solar radiation at any Italian location using as input few extensively measured meteorological parameters is proposed. In fact the daily diffuse radiation D, MJ.m−2.day−1, here is correlated with only the relative sunshine duration sS and the noon altitude of the sun on the 15th of the month hn, degrees, by the following equation: D=7(sS−(sinhn)1.55 . The validity of this formula is verified using monthly mean daily data from four Italian stations displaced at various latitudes or altitudes or geographical situations (inland or coastal site). The test results show that the deviations between the measured and the computed val…
Instantaneous hourly and daily radiation on tilted surfaces
1991
A simple model to evaluate the irradiance incident on tilted surfaces of various orientations is proposed in this paper. It is based on the knowledge of the monthly daily average values of global and diffuse radiation on horizontal surfaces and their distributions over a period of a day. These distributions are approximated by a modified Gaussian expression with two parameters, which take into account the morning-to-afternoon asymmetries. Integrating the irradiance over a period of an hour or a day, values of monthly hourly average and daily on variously oriented surfaces have been calculated for the locations of Barcelona, Genoa, and Montreal. The calculated values are generally in good ag…
Instantaneous distribution of global and diffuse radiation on horizontal surfaces
1991
Abstract The aim of this paper is to obtain a general expression for estimating both the instantaneous global and diffuse radiations on horizontal surfaces from the respective daily values. The proposed expression is a modified Gaussian distribution with two parameters which take into account its width and the asymmetries between morning and afternoon hours. The performance of the method has been tested by comparing the theoretical hourly results with the experimental data of six actinometric stations with different geographical location and climatic conditions. The comparison has shown that the method here proposed is accurate for both the diffuse and global radiation.