3,037 research outputs found
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
Get PDFUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
Assessing upcycling of waste bioplastics for production of sustainable carbon black substitute
No full textCarbon black is a product with multiple applications, including use as an additive for tyres or plastics, as well as ink or toner. Current methods of carbon black production are based on incomplete combustion of fossil fuels, followed by quenching, resulting in a high carbon footprint and related emissions. Even though unintended, biodegradable bioplastics at the end of life still pose problems to waste management plants. Most notably, the time required for bioplastics to biodegrade is longer than the typical residence time in state-of-the-art processes, such as anaerobic digestion and composting. This causes incomplete degradation and reduces the efficiency of waste treatment facilities. This work provides an experimental evaluation of a novel method of production of carbon black, using bioplastic waste (namely, cellulose acetate) as a feedstock. The proposed system consists of hydrothermal carbonisation (HTC) and subsequent pyrolysis of separated solid products. The novel product exhibits morphology and structure similar to commercial carbon black and high thermal stability. BET surface area as high as 175 m2/g can be achieved by combining hydrothermal carbonisation performed at 250 °C followed by pyrolysis at 600 °C. Further increase in pyrolysis temperature provided no additional benefits and resulted in collapse of the pores within the mesoporous range, with detrimental influence on BET surface and pore volume
Rich, Sturmian, and trapezoidal words
Get PDFIn this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity
Microcomposites of poly(ε-caprolactone) and poly(methyl methacrylate) prepared by suspension polymerization in the presence of poly(ε-caprolactone) macromonomer
Get PDFPoly(methyl methacrylate)-poly(ε-caprolactone) (PMMA/PCL) microparticles were synthesized by suspension polymerization of methyl methacrylate in the presence of PCL. The incorporation of a small amount of a macromonomer, methacryloyl-terminated PCL (M-PCL), into the reaction mixture, led to the formation of grafted systems, namely PMMA-g-PCL/PCL. The synthesis of the macromonomer and its characterization by nuclear magnetic spectroscopy (1H NMR) is described. The role of M-PCL as an effective compatibilizing agent in the composite was investigated. PMMA/PCL and PMMA-g-PCL/PCL composites were fully characterized by 1H NMR, gel permeation chromatography (GPC) and thermal analysis, including thermogravimetric, analysis (TGA), conventional differential scanning calorimetry (DSC), modulated DSC (MDSC) and dynamic mechanical thermal analysis (DMTA). Finally, the morphology of the prepared systems was investigated by scanning electron microscopy (SEM). The addition of compatibilizing agent led the formation of a more homogeneous microcomposite with improved mechanical properties.Fil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Kesenci,Kemal. Universitá di Trento; ItaliaFil: Fambri,Luca. Universitá di Trento; ItaliaFil: Migliaresi,Claudio. Universitá di Trento; ItaliaFil: Gallardo, Alberto. Consejo Superior de Investigaciones Científicas; EspañaFil: San Roman, Julio. Consejo Superior de Investigaciones Científicas; Españ
Characterization Results for the Poset Based Representation of Topological Relations - I: Introduction and Models
No full text@article{DBLP:journals/informaticaSI/ForlizziN99,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - I: Introduction and Models.},
journal = {Informatica (Slovenia)},
volume = {23},
number = {2},
year = {1999},
bibsource = {DBLP, http://dblp.uni-trier.de}
Characterization Results for the Poset Based Representation of Topological Relations - II: Intersection and Union
No full text@article{DBLP:journals/informaticaSI/ForlizziN00,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - II: Intersection and Union.},
journal = {Informatica (Slovenia)},
volume = {24},
number = {1},
year = {2000},
bibsource = {DBLP, http://dblp.uni-trier.de}
System-on-chip Computing and Interconnection Architectures for Telecommunications and Signal Processing
No full textThis dissertation proposes novel architectures and design techniques targeting SoC building blocks for telecommunications and signal processing applications.
Hardware implementation of Low-Density Parity-Check decoders is approached at both the algorithmic and the architecture level. Low-Density Parity-Check codes are a promising coding scheme for future communication standards due to their outstanding error correction performance.
This work proposes a methodology for analyzing effects of finite precision arithmetic on error correction performance and hardware complexity. The methodology is throughout employed for co-designing the decoder. First, a low-complexity check node based on the P-output decoding principle is designed and characterized on a CMOS standard-cells library. Results demonstrate implementation loss below 0.2 dB down to BER of 10^{-8} and a saving in complexity up to 59% with respect to other works in recent literature. High-throughput and low-latency issues are addressed with modified single-phase decoding schedules. A new "memory-aware" schedule is proposed requiring down to 20% of memory with respect to the traditional two-phase flooding decoding. Additionally, throughput is doubled and logic complexity reduced of 12%. These advantages are traded-off with error correction performance, thus making the solution attractive only for long codes, as those adopted in the DVB-S2 standard. The "layered decoding" principle is extended to those codes not specifically conceived for this technique. Proposed architectures exhibit complexity savings in the order of 40% for both area and power consumption figures, while implementation loss is smaller than 0.05 dB.
Most modern communication standards employ Orthogonal Frequency Division Multiplexing as part of their physical layer. The core of OFDM is the Fast Fourier Transform and its inverse in charge of symbols (de)modulation. Requirements on throughput and energy efficiency call for FFT hardware implementation, while ubiquity of FFT suggests the design of parametric, re-configurable and re-usable IP hardware macrocells. In this context, this thesis describes an FFT/IFFT core compiler particularly suited for implementation of OFDM communication systems. The tool employs an accuracy-driven configuration engine which automatically profiles the internal arithmetic and generates a core with minimum operands bit-width and thus minimum circuit complexity. The engine performs a closed-loop optimization over three different internal arithmetic models (fixed-point, block floating-point and convergent block floating-point) using the numerical accuracy budget given by the user as a reference point. The flexibility and re-usability of the proposed macrocell are illustrated through several case studies which encompass all current state-of-the-art OFDM communications standards (WLAN, WMAN, xDSL, DVB-T/H, DAB and UWB). Implementations results are presented for two deep sub-micron standard-cells libraries (65 and 90 nm) and commercially available FPGA devices. Compared with other FFT core compilers, the proposed environment produces macrocells with lower circuit complexity and same system level performance (throughput, transform size and numerical accuracy).
The final part of this dissertation focuses on the Network-on-Chip design paradigm whose goal is building scalable communication infrastructures connecting hundreds of core. A low-complexity link architecture for mesochronous on-chip communication is discussed. The link enables skew constraint looseness in the clock tree synthesis, frequency speed-up, power consumption reduction and faster back-end turnarounds. The proposed architecture reaches a maximum clock frequency of 1 GHz on 65 nm low-leakage CMOS standard-cells library. In a complex test case with a full-blown NoC infrastructure, the link overhead is only 3% of chip area and 0.5% of leakage power consumption.
Finally, a new methodology, named metacoding, is proposed. Metacoding generates correct-by-construction technology independent RTL codebases for NoC building blocks. The RTL coding phase is abstracted and modeled with an Object Oriented framework, integrated within a commercial tool for IP packaging (Synopsys CoreTools suite). Compared with traditional coding styles based on pre-processor directives, metacoding produces 65% smaller codebases and reduces the configurations to verify up to three orders of magnitude
Production and characterization of novel EPDM/NBR panels with paraffin for potential thermal energy storage applications
No full textInnovative panels suitable for the thermal management of closed systems with potential applications for buildings have been produced combining an Ethylene-Propylene Diene Monomer (EPDM) rubber with a paraffin wax having a melting temperature of 28 °C. The compounded material was confined in a Nitrile Butadiene Rubber (NBR) envelope that impeded any paraffin leakage. According to differential scanning calorimetry, the effective thermal energy efficiency of the PCM (PCMeff) in the panel, was 37 wt% with a melting enthalpy of about 100 J/g. The homogeneous distribution of paraffin within the elastomeric matrix was verified both through scanning electron microscopy and through temperature monitoring of the panel’s surface during heating/cooling cycles, performed by an infrared camera. It was also observed that the thermal conductivity of the panels was the same above or below the melting point of paraffin with values of about 0.15 W/m·K. Shore A hardness tests revealed the dependence on the temperature due to the presence of paraffin that acted as softener above its melting point and as hardener below. The evaluation of the thermal energy storage performance of the panels was verified by monitoring the internal temperature of testing boxes (310x310x310 mm3) insulated with these elastomeric panels during heating/cooling cycles performed in a temperature interval from 16 to 31 °C (typical summer conditions in Trento, Italy). The presence of paraffin within the elastomeric panels allowed to keep the internal temperature of the box always lower than 27 °C, with a delay of the peak temperature of about 1 h with respect to a reference non-insulated box. The results of testing boxes have been confirmed after 15 months, showing the reproducibility and the stability of the assembled lab configuration
A General Formulation to Describe Empirical Rainfall Thresholds for Landslides
Get PDFAbstractIn this paper, a brief description of the Generalized FLaIR Model (GFM, De Luca and Versace, 2016) is provided, that is able to reproduce all the empirical thresholds proposed in literature, aimed to forecast landslides triggered by rainfall. In particular, this paper focuses on Antecedent Precipitation (AP) schemes. The paper demonstrates that these are particular solutions of the GFM and will exemplify this using AP schemes for NE Italy1, Seattle2 and Nicaragua - El Salvador3
The technological specialization of countries : an analysis of patent data
Get PDFNew methods of analysis of patent statistics allow assessing country profiles of technological specialization for the period 1990-2006. We witness a modest decrease in levels of specialization, which we show to be negatively influenced by country size and degree of internationalization of inventive activities
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