56 research outputs found
Microplastic Contamination in Protected Areas of the Gulf of Venice
We investigated the concentration and composition of plastics in 7 Special Areas of Conservation (SACs) from the Gulf of Venice (northern Adriatic Sea). A total of 42 sediment samples were analyzed from 21 sites from 2017 to 2018. All sites except one were found to be polluted by plastics, with density ranging between 2250 and 28.4 items kg−1. Microplastics ranged from 100 to 61.6% of the collected plastics. Fragments were more represented than filaments. The greatest plastic concentrations were generally recorded in western SACs. Identification through FT-IR spectroscopy evidenced the presence of 8 polymer types: in western SACS, the majority were low-density polymers (PE, PP, PS, and TPU), while in eastern SACs they were high-density polymers (PET, nylon, and PVC). In addition to the role of large rivers (all on the western side of the Gulf) in conveying plastics into the sea, a possible role of the cyclonic water circulation of the northern Adriatic Sea on distribution and composition of plastics along the Gulf coasts is likely
Valoración de la sustentabilidad de sistemas de labranza: estudio de caso en el so bonaerense
El objetivo del trabajo es valorar la sustentabilidad a escala predial de sistemas de laboreo alternativos: siembra directa versus laboreo convencional, incorporando la cuantificación económica de impactos ambientales sobre la calidad del suelo. El análisis se desarrolla en un caso de estudio del sudoeste bonaerense, para el perÃodo 1986-2008. Se calcularon costos y beneficios ambientales a partir del balance de nutrientes por el método del costo de reposición; y se valoraron los servicios ambientales de ambas técnicas mediante la función de producción ajustada, atendiendo sus rendimientos fÃsicos. Finalmente se realizó un análisis multicriterio con indicadores representativos de las dimensiones de la sustentabilidad (ecológica, económica y social) de modo de comparar con una visión sistémica e integral los sistemas de labranza. Se concluye que la siembra directa presenta un mejor desempeño desde las perspectivas estudiadas.
Asimismo, la valoración de la sustentabilidad por su complejidad, requiere un tratamiento interdisciplinario y no se agota en la aplicación de un solo método.Publicado en las Actas de las III Jornadas Nacionales de Suelos de Ambientes Semiáridos
Effects of poly(L-lactide-ε-caprolactone) and magnesium hydroxide additives on physico-mechanical properties and degradation of poly(L-lactic acid)
Recommendations for airway control and difficult airway management in thoracic anesthesia and lung separation procedures
Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes
Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening
Photopolymerization kinetics of UV curable systems for polymer dispersed liquid crystal
The preparation methods and the materials used
for the production of polymer dispersed liquid crystals
(PDLC) are reported. The photopolymerization
induced phase separation (PIPS) method is also
discussed in terms of the kinetic behaviour observed
for these materials. In addition, the thermodynamic
aspects of the phase separation have been briefly
included in the text describing the thermal properties
of the mixture before and after UV curing. The
determination of the experimental kinetic parameters
and the techniques to study photopolymerization
reactions are also discussed for UV curable
formulations containing mono(meth)acrylate and
diacrylate monomers and reactive oligomers. Finally,
an example of the photopolymerization kinetic behaviou
Using DSC and DMTA for the study of thermo-mechanical treatments improving the transformational behavior of Ti-rich nitinol sheets
The influence of thermo-mechanical treatments on TiNi shape memory alloys has been studied with Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Thermal Analysis (DMTA). The DSC is a widely used technique to study the transformation temperatures and the behaviour of TiNi alloys. Even though DMTA is a well-known technique, it is not so commonly used with this kind of materials. In this paper both techniques have been applied to TiNi strips subjected to different cycles of annealing, cold rolling and quenching. The aim of the work is to find and characterise the best thermo-mechanical treatment in TiNi thin sheets that controls the transformation temperature and the recovery force during constrained activation. The results of DSC and DMTA have been compared to find a correlation between the two different techniques that may allow the behaviour of a constrained shape memory alloy and the influence of an applied stress on the transformation temperatures to be studied
Studio dell’influenza dei trattamenti termomeccanici sulle temperature di trasformazione di lamine in lega Ti-Ni
L’influenza di trattamenti termomeccanici su lamine in leghe a memoria di forma Ti-Ni è stata studiata mediante calorimetria differenziale a scansione (DSC) ed analizzatore dinamico meccanico in temperatura (DMTA). L’analisi DSC è un metodo spesso usato in letteratura per determinare le temperature di trasformazione, mentre lo studio tramite DMTA è meno applicato a questo tipo di materiali. Sottoponendo le lamine a memoria di forma a trattamenti di ricottura, deformazione a freddo e successiva tempra a diverse temperature è stato possibile individuare la temperatura di tempra necessaria per controllare l’effetto memoria di forma. Inoltre è stato possibile correlare i risultati ottenuti dalla DSC con quelli ottenuti dalla tecnica DMTA
Composizione sigillante per per l’isolamento di dispositivi sensibili alla permeazione di umidità dall’ambiente esterno
The present invention relates to a sealant composition for the isolation of devices that are sensitive to permeation of moisture from the external environment.
It is well known that the insulating structures for moisture-sensitive devices are made with the aid of sealants compositions having a low rate of water vapor transmission
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