Physiological, growth and root biochemical responses of Arbutus unedo and Quercus suber seedlings to UV radiation and water availability before and after aboveground biomass removal

2019 ◽  
Vol 168 ◽  
pp. 103861 ◽  
Author(s):  
L. Díaz-Guerra ◽  
L. Llorens ◽  
T.L. Bell ◽  
J. Font ◽  
J.A. González ◽  
...  
Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Antonella Patti ◽  
Domenico Acierno

Polyurethane is a polymer adaptable to different scientific and industrial requirements; nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment; but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.


2020 ◽  
Vol 66 (No. 1) ◽  
pp. 47-56
Author(s):  
Ning Zong ◽  
Peili Shi

To investigate how clipping (CL) regulates the effects of nutrient addition, an experiment, including CL and nitrogen (N) addition, was conducted in an alpine meadow. Nitrogen treatment increased community coverage (48–113% higher than the control) and aboveground biomass (29–117% higher than the control), which was mainly attributed to grass growth. Both N and N + CL treatments showed a tendency to reducing species richness, while significant reduction only occurred in 2016 and 2017 in CL treatment. Clipping showed a tendency to decrease community cover (3–37% lower than the control) and aboveground biomass (2–34% lower than the control), while N + CL treatment had no effect, indicating that clipping can eliminate the simulated effects of N addition. Nitrogen addition significantly increased soil inorganic N (SIN, 528–1230% higher than the control), while SIN in N + CL was 25–48% lower than N treatment. The decrease in stimulated effects in N + CL was attributed to SIN decrease, which resulted from the aboveground biomass removal by clipping. Our results show that clipping can take away aboveground biomass and cause soil nutrients to decrease, which slows down the degraded grassland recovery. This suggests that grazing exclusion may eliminate the effect of nitrogen deposition on aboveground production in alpine grasslands.


2012 ◽  
Vol 147 (2) ◽  
pp. 234-247 ◽  
Author(s):  
Meritxell Bernal ◽  
Laura Llorens ◽  
Jordi Badosa ◽  
Dolors Verdaguer

2021 ◽  
Author(s):  
Ana Patrícia Poeiras ◽  
Cordula Voguel ◽  
Björn Günther ◽  
Constança Camilo-Alves ◽  
Peter Surový ◽  
...  

Abstract The bark of cork oak (Quercus suber L.) is mostly used for cork stopper production, whereas bark is undergoing a series of industrial procedures, boiling usually leading to changes in the characteristics of the tissue. Trees are traditionally grown under natural conditions; however, irrigation is now being used in plantations. These permanent water availability affects cork-oak development, while its effects on industrial procedures is unknown. This study provides a first insight into the behaviour of the cell walls of cork during the process of swelling and boiling when trees have been grown under irrigation, subject to a specific water regime. Cork tissue was analysed using environmental and scanning electron microscopy under three regimes: raw conditions; following immersion in water; and after boiling. Additionally, the radial expansion of samples was determined. The results showed greater cell-wall expansion in cork from the irrigated site than cork from the traditional rainfed plot, when hydrated for 24h. After boiling, the cell walls of the rainfed site were thinner than in the raw stage, in contrast to the irrigated cork. This study suggests that irrigation during cork-oak growth produces a higher capacity for adsorption, increasing cell-wall thickness from the raw stage to the boiling stage.


2018 ◽  
Vol 44 ◽  
pp. 00122 ◽  
Author(s):  
Ewelina Niedzielska ◽  
Anna Masek

The aim of this work was carry out accelarated process of ageing for cyclic olefin copolymer ethylene – norbornene (Topas). The Topas cyclic olefin copolymer (COC) family characterize high transparency, excellent mechanical properties and low water permeability. The influence of external factors such as UV radiation, elevated temperature, oxygen effect and humidity causing degradation of polymer macroparticles was also investigated. The properties of the polymer before and after weathering and UV radiation were also compared. Degradability was examinated by measuring color change, FTIR spectrum analysis and determination of the ageing factor k. The tensile strength, elongation at break and hardness of composites by Shore A method were measured. The synergistic effect of temperature, humidity and UV radiation reduces the mechanical properties of the samples tested, while the interaction of only UV radiation on the samples causes a significant change color.


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