84 research outputs found
Three-dimensional architecture and mechanical properties of bovine bone mixed with autologous platelet liquid, blood, or physiological water: An in vitro study
In recent years, several techniques and material options have been investigated and developed for bone defect repair and regeneration. The progress in studies of composite graft materials and autologous platelet-derived growth factors for bone regeneration in dentistry and their biological and biomechanical properties has improved clinical strategies and results. The aim of this study was to evaluate the three-dimensional architecture and mechanical properties of three different combinations of composite bovine graft, adding autologous platelet liquid (APL), blood, or physiological water. One experimental group for each combination of biomaterials was created. In particular, in Group I, the bovine graft was mixed with APL; in Group II, it was mixed with blood, and in Group III, the biomaterial graft was combined with physiological water. Then, the composite biomaterials were evaluated by scanning electron microscopy (SEM), and a compression-loading test was conducted. The evaluation showed a statistical significance (p < 0.01) of the elastic regime of deformation resistance, in which the combination of APL with bone graft resulted in an 875% increase in the mechanical resistance. The protocol of APL mixed with bovine bone graft produced a composite sticky graft block that was capable of increasing the mechanical properties in order to improve its clinical use in the treatment of the maxillary bone defects
Opis svojstava ekstra djevičanskog maslinovog ulja dobivenog iz raznih kultivara
The determination of some minor components of extra virgin olive oil, and in particular of the polyphenolic fraction of pigments and fragrances, can contribute to the characterization of the monovarietal productions: the quali-quantitative assessment of these substances can in fact contribute to the valorisation of typicalities and, at the same time, consent to the optimisation of the operational techniques during the processing and the eventual blending.
The analytical techniques, applied here for the characterisation of extra virgin olive oil of Abruzzo and Istria, have highlighted that chemical composition can enhance the valorisation of these typical products. Nevertheless, further sampling program is needed to evidence typical composition profile that might be used as “origin markers”.Određivarije nekih manjih komponenata ekstra djevičanskog maslinovog ulja, naročito polifenolne frakcije pigmemta i mirisa, može doprinijeti svojstvima monovarijetetnih proizvoda: kvalitativna i kvalitativna procjena tih supstancija može zapravo doprinijeti valorizaciji tipičnosti te, istodobno omogućiti optimizaciju operativnih tehnika za vrijeme prerade i miješanja.
Analitičke tehnike, ovdje primijenjene za opis svojstava ekstra djevičanskog maslinovog ulja iz Abruzza i Istre pokazuju da kemijski sastav može popraviti vrijednost ovih tipičnih proizvoda. Ipak, potreban je dodatni program uzorkovanja da se dokaže tipični profil sas¬tava, što se može upotrijebiti kao "oznaka podrijetla"
Analysing the performance of MCECs over a wide range of operating temperatures
Hydrogen production through water electrolysis has gained significant attention in the past years as a means of tackling the problem of the imbalance between the intermittent rate of electricity production from renewable sources and the continuous electricity demand from end users. Recently, much of the effort has been shifted toward the electrolysis of steam rather than water, for example in solid oxide cells, which operate at temperatures around 800°C. In this manner, part of the energy required for the conversion to hydrogen is provided as heat rather than electricity. At the same time, the high temperature levels require the use of highly resistant materials, which increase the overall cost of the process. An interesting alternative is represented by molten carbonate electrolysis cells (MCECs), operating at temperatures well below 700°C. In the present work, a molten carbonate cell was operated in a lower temperature range (490-550°C) by changing the composition of the electrolyte mixture. The data obtained, along with experimental results at higher temperature (570-650°C) available in the literature, was analyzed using a 0D model accounting for Ohmic and activation overpotentials to determine the correlation between current and potential. It was found that, while the dependence of Ohmic losses on temperatures is discontinuous when cell operation is switched from the lower to the higher temperature range, activation losses vary with continuity. This result provides important insight on the performance of MCECs that can serve as a basis for future studies
Calcium Looping for Thermochemical Storage: Assessment of Intrinsic Reaction Rate and Estimate of Kinetic/Transport Parameters for Synthetic CaO/Mayenite Particles from TGA Data
Mayenite-supported CaO represents an affordable and safetycompliant candidate material for thermochemical storage processes. We here analyze the thermogravimetric analysis (TGA) performance of synthetic CaO/mayenite micrometric powder under carbonatation/calcination looping and develop a model to interpret and analyze the experimental results. In the experimental campaign, calcination is run at 900 degrees C, while the carbonatation temperature is varied between 600 and 800 degrees C. For the carbonatation reaction, a generalized shrinking core model assuming a thermodynamically consistent first-order kinetic and a conversion-dependent diffusivity of CO2 inside the porous CaCO3 layer is validated through TGA carbonatation tests conducted with CO2/N-2 mixtures at different compositions. Interestingly, the kinetic constant of this reaction is found to be relatively insensitive to the temperature in the interval considered. In contrast, diffusion-limited regimes are never found for the calcination reaction so that this phase of the cycle can be predicted based on a single kinetic constant of the heterogeneous reaction. This constant is found to follow the typical Arrhenius-type dependence on temperature. Sizably different kinetic and transport parameters are obtained in the first carbonation performed on virgin CaO/mayenite particles with respect to those associated with subsequent cycles. When different parameters are afforded for the first and following cycles, the shrinking core model proposed closely predicts the TGA data over five CaO/CaCO3 cycles. The results found constitute an essential preliminary piece of information for designing equipment geometry and operating conditions of industrial-scale reactors. In this respect, knowledge of the parameters defining the intrinsic reaction rates and diffusive transport is essential in defining the optimal conversion of the material associated with minimal looping time
Ruolo dell’imaging TC nella valutazione post-mortem dei soggetti deceduti per caduta da altezze elevate: nostra esperienza
The CT-v can therefore be considered an effective method as an aid in the autopsy evaluation
of individuals who died for various causes; in particular, in the case of deaths due to accidental falls from high altitudes, is able to identify the primary cause of death and all the epiphenomena due to precipitation
SHOT-DEAD CT-VIRTOPSY: OUR EXPERIENCE
To illustrate the potential of CT-virtopsy (CT-v) as a valid help in post-mortem evaluation in gunshot-dead people.
To explain as it can support, complete and, in some special cases, be a substitute of body-opening autopsy.
To stress its role in establishing cause of death, in dating the succession of lethal events occurred in the body and, possibly, in identifying the corpse
HOW MUCH DANGEROUS IS CT ACCORDING TO PATIENTS AND HOW DOES DOSE BILL AFFECT THEIR PERCEPTION OF IONIZING RADIATION?
In our work, we attempted to assess patients' understanding of relative radiation exposure
by asking them to compare the amount of radiation exposure from CT compared to other
carcinogenic factors before and after knowing their dose bill
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