Feasibility of a Local Production Chain for Structural Timber in Sardinia, Italy

The construction sector is currently responsible for over 30% of the consumption of natural resources and the release of solid waste and pollution into the environment. This situation is even more serious in closed communities such as islands, economically highly dependent on the outside world. One of the possible interventions to reverse this trend is the use of eco-sustainable construction materials such as wood, produced through supply chains with a low environmental impact. This paper reports on a research activity that analyzed the feasibility of implementing a sustainable local supply chain in Sardinia to produce Cross-Laminated Timber (CLT) panels made of locally grown wood. This research has experimentally carried out the entire supply chain process: (i) choice and collection of the raw material in the forest for producing strength-graded boards to manufacture laminated timber, (ii) manufacturing of CLT panel prototypes, and (iii) determination of CLT panels’ mechanical performance through laboratory tests. This experimentation allowed, on the one hand, to evaluate the performance and competitiveness of CLT panels made of local wood, and on the other hand, to identify the criticalities that currently hinder the implementation of this supply chain in Sardinia, and to propose possible actions to solve them

Prediction of maritime pine boards modulus of elasticity by means of sonic testing on green timber

Timber buildings are experiencing a rapid diffusion due to their good performance and their sustainability; however, some steps of structural timber production process, such as drying, are energy-intensive and environmentally impactful, and many wood species are also affected by low yield. Therefore, it would be important to determine the quality of the green material, that is, in wet condition, before undergoing the most impactful and expensive production steps. This paper describes a research aimed at quantifying the variation of the dynamic modulus of elasticity MoEdyn, which is commonly used for structural timber mechanical grading, from wet to dry condition in Sardinian maritime pine boards to be used for the production of laminated timber, and to examine the relationship between wet and dry MoEdyn . The MoEdyn was determined from measurements of the velocity of sonic waves propagating through the boards. The results show that the dry MoEdyn can be estimated starting from boards sonic testing in the wet condition, so providing a basis for implementing Sardinian maritime pine pre-grading in order to obtain the reduction of manufacturing costs, the abatement of environmental impact, and the increase of structural grade yield

Investigating the high-frequency spectral features of SNRs Tycho, W44 and IC443 with the Sardinia Radio Telescope

The main characteristics in the radio continuum spectra of Supernova Remnants (SNRs) result from simple synchrotron emission. In addition, electron acceleration mechanisms can shape the spectra in specific ways, especially at high radio frequencies. These features are connected to the age and the peculiar conditions of the local interstellar medium interacting with the SNR. Whereas the bulk radio emission is expected at up to $20-50$ GHz, sensitive high-resolution images of SNRs above 10 GHz are lacking and are not easily achievable, especially in the confused regions of the Galactic Plane. In the framework of the early science observations with the Sardinia Radio Telescope in February-March 2016, we obtained high-resolution images of SNRs Tycho, W44 and IC443 that provided accurate integrated flux density measurements at 21.4 GHz: 8.8 $\pm$ 0.9 Jy for Tycho, 25 $\pm$ 3 Jy for W44 and 66 $\pm$ 7 Jy for IC443. We coupled the SRT measurements with radio data available in the literature in order to characterise the integrated and spatially-resolved spectra of these SNRs, and to find significant frequency- and region-dependent spectral slope variations. For the first time, we provide direct evidence of a spectral break in the radio spectral energy distribution of W44 at an exponential cutoff frequency of 15 $\pm$ 2 GHz. This result constrains the maximum energy of the accelerated electrons in the range $6-13$ GeV, in agreement with predictions indirectly derived from AGILE and \textit{Fermi}-LAT gamma-ray observations. With regard to IC443, our results confirm the noticeable presence of a bump in the integrated spectrum around $20-70$ GHz that could result from a spinning dust emission mechanism.Comment: 12 pages, 9 figure

Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope at 1.5 GHz and 7 GHz

Observations of supernova remnants (SNRs) are a powerful tool for investigating the later stages of stellar evolution, the properties of the ambient interstellar medium, and the physics of particle acceleration and shocks. For a fraction of SNRs, multi-wavelength coverage from radio to ultra high-energies has been provided, constraining their contributions to the production of Galactic cosmic rays. Although radio emission is the most common identifier of SNRs and a prime probe for refining models, high-resolution images at frequencies above 5 GHz are surprisingly lacking, even for bright and well-known SNRs such as IC443 and W44. In the frameworks of the Astronomical Validation and Early Science Program with the 64-m single-dish Sardinia Radio Telescope, we provided, for the first time, single-dish deep imaging at 7 GHz of the IC443 and W44 complexes coupled with spatially-resolved spectra in the 1.5-7 GHz frequency range. Our images were obtained through on-the-fly mapping techniques, providing antenna beam oversampling and resulting in accurate continuum flux density measurements. The integrated flux densities associated with IC443 are S_1.5GHz = 134 +/- 4 Jy and S_7GHz = 67 +/- 3 Jy. For W44, we measured total flux densities of S_1.5GHz = 214 +/- 6 Jy and S_7GHz = 94 +/- 4 Jy. Spectral index maps provide evidence of a wide physical parameter scatter among different SNR regions: a flat spectrum is observed from the brightest SNR regions at the shock, while steeper spectral indices (up to 0.7) are observed in fainter cooling regions, disentangling in this way different populations and spectra of radio/gamma-ray-emitting electrons in these SNRs.Comment: 13 pages, 9 figures, accepted for publication to MNRAS on 18 May 201

Application of infrared thermography in civil engineering: Limits and drawbacks

Infrared thermography (IRT) is an effective diagnostic methodology for existing buildings monitoring, whose efficiency is however affected by the operator’s technical knowledge. This paper presents experimental research aimed at evaluating the accuracy of IRT temperature measurements with respect to the incorrect setting of five input parameters required to be set by the operator: emissivity, reflected apparent temperature, ambient temperature, relative humidity, and distance. The goal was to highlight how their accurate evaluation and setting affects the thermographic survey and the post-processing stage. To this end, IRT experimental investigations were carried out on materials characterized by different emissivity and surface roughness, such as concrete, granite and steel. The experimentation outcome has pointed out the factors that most affect the temperature measurement error and allowed to quantify the error on the temperature measurements deriving from the incorrect setting of these parameters during the acquisition phase of the thermogram

Policy design for climate change mitigation and adaptation in sheep farming: Insights from a study of the knowledge transfer chain

Low innovation adoption rates in agriculture have spurred intense research on farmers’ attitudes and motivations. Little attention has been paid to attitudes of other important actors in the knowledge transfer chain. Evidence indeed suggests that adoption rarely happens at the farm level, but requires the right inputs from science and extension services. Divergent attitudes among actors in the knowledge transfer chain may hence contribute to low adoption rates by transferring insufficient, outdated, irrelevant and/or incorrect information. This study is an investigation on attitudes towards climate change mitigation and adaptation of three classes of actors: sheep farmers, researchers involved in fields related to sheep farming and extension officers from private companies and public agencies. The investigation is based on data collected through self-administered questionnaires submitted to 165 participants to agricultural field days in Sardinia (Italy). The sample consists of sheep farmers (37,5%), researchers (16,4%), extension officers (32,1%) and other agricultural workers or students (14 %). In order to assess differences in attitude and identify the sources of attitudinal divergence, the study adopts Kolmogorov – Smirnov (KS) equality-of-distribution tests and Partial-least square structural equation modelling (PLS-SEM). Comparing and contrasting attitudes towards several topics related to GHG emission mitigation and adaptation to climate change reveal that researchers and extension officers have different attitudes towards innovation for mitigating GHG, that in turn depend on different information and beliefs on the causes and effects of climate change. This context is less than optimal to promote adoption of climate change mitigation or adaptation strategies. Climate change science and policy design need to recognise the complexity of knowledge transmission and the multiplicity of attitudes and beliefs that inform and affect the process. To mitigate the impact of diverging attitudes and beliefs among researchers and extension officers tailored communication strategies should avoid controversial issues and focus on benefits of innovation on farm efficiency. In turn, this would build trust and cooperation among all the actors in the knowledge transfer chain. Only when cooperation is assured, one could be confident that the information delivered to farmers is scientifically sound, relevant, value-neutral and useful in changing farmers' behaviour

Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129

We present new observations of the galaxy cluster 3C 129 obtained with the Sardinia Radio Telescope in the frequency range 6000-7200 MHz, with the aim to image the large-angular-scale emission at high-frequency of the radio sources located in this cluster of galaxies. The data were acquired using the recently-commissioned ROACH2-based backend to produce full-Stokes image cubes of an area of 1 deg x 1 deg centered on the radio source 3C 129. We modeled and deconvolved the telescope beam pattern from the data. We also measured the instrumental polarization beam patterns to correct the polarization images for off-axis instrumental polarization. Total intensity images at an angular resolution of 2.9 arcmin were obtained for the tailed radio galaxy 3C 129 and for 13 more sources in the field, including 3C 129.1 at the galaxy cluster center. These data were used, in combination with literature data at lower frequencies, to derive the variation of the synchrotron spectrum of 3C 129 along the tail of the radio source. If the magnetic field is at the equipartition value, we showed that the lifetimes of radiating electrons result in a radiative age for 3C 129 of t_syn = 267 +/- 26 Myrs. Assuming a linear projected length of 488 kpc for the tail, we deduced that 3C 129 is moving supersonically with a Mach number of M=v_gal/c_s=1.47. Linearly polarized emission was clearly detected for both 3C 129 and 3C 129.1. The linear polarization measured for 3C 129 reaches levels as high as 70% in the faintest region of the source where the magnetic field is aligned with the direction of the tail.Comment: 19 pages, 17 figures, accepted for publication in MNRA

Effect of beetroot juice supplementation on aerobic response during swimming

The beneficial effects of beetroot juice supplementation (BJS) have been tested during cycling, walking, and running. The purpose of the present study was to investigate whether BJS can also improve performance in swimmers. Fourteen moderately trained male master swimmers were recruited and underwent two incremental swimming tests randomly assigned in a pool during which workload, oxygen uptake (VO2), carbon dioxide production (VCO2), pulmonary ventilation (VE), and aerobic energy cost (AEC) of swimming were measured. One was a control swimming test (CSW) and the other a swimming test after six days of BJS (0.5l/day organic beetroot juice containing about 5.5 mmol of NO3 -). Results show that workload at anaerobic threshold was significantly increased by BJS as compared to the CSW test (6.3 ± 1 and 6.7 ± 1.1 kg during the CSW and the BJS test respectively). Moreover, AEC was significantly reduced during the BJS test (1.9 ± 0.5 during the SW test vs. 1.7 ± 0.3 kcal·kg-1·h-1 during the BJS test). The other variables lacked a statistically significant effect with BJS. The present investigation provides evidence that BJS positively affects performance of swimmers as it reduces the AEC and increases the workload at anaerobic threshold

NL mind-best: aweb server for ligands and proteins discovery; theoretic experimental study of proteins of giardia lamblia

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