Search results for "Stabilization"

Photo- and thermo- oxidative stabilization of polymer-based nanocomposites through the incorporation of CNTs with in-built antioxidant activity

2017

Antioxidant molecules are physically immobilized onto multi-walled carbon nanotubes (CNTs) surface and the resulting hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite with enhanced photo- and thermo- oxidation resistance. Natural phenols derivatives, such as quercetin and α-tocopherol, are known to be an excellent antioxidant for polyethylene, but when they are physically immobilized on CNTs the stabilizing activity strongly increase. This is due to a synergic effect stemming from the physical interaction between the antioxidants and CNTs, which cannot provide a similar stabilizing action if used separately. In particular, it is proposed t…

Predicting the photoageing and photostabilization of polymer nanocomposites

2010

Autonomous frequency stabilization of two extended cavity diode lasers at the potassium wavelength on a sounding rocket

2016

We have developed, assembled, and flight-proven a stable, compact, and autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during a sounding rocket flight by means of frequency modulation spectroscopy (FMS) of 39^K and offset locking techniques based on the beat note of the two ECDLs. The frequency stabilization as well as additional hard- and software to test hot redundancy mechanisms were implemented as part of a state-machine, which controlled the experiment completely autonomously throughout the entire flight mission.

A Review of the Current Knowledge of Thermal Stability of Anthocyanins and Approaches to Their Stabilization to Heat

2021

Anthocyanins are colored valuable biocompounds, of which extraction increases globally, although functional applications are restrained by their limited environmental stability. Temperature is a critical parameter of food industrial processing that impacts on the food matrix, particularly affecting heat-sensitive compounds such as anthocyanins. Due to the notable scientific progress in the field of thermal stability of anthocyanins, an analytical and synthetic integration of published data is required. This review focuses on the molecular mechanisms and the kinetic parameters of anthocyanin degradation during heating, both in extracts and real food matrices. Several kinetic models (Arrheniu…

Collapsibility of metastable sand by non-conventional oedometer tests

2018

The stability of foundations soils could represent a clear and present threat for the conservation of even well preserved buildings, particularly for Architectural heritage conservation and land art heritage. A dramatic case is the presence of collapsible metastable sands as foundation soils, as it occurs in the sacral complex Valle dei Templi in Agrigento. This site listed by UNESCO, stands on a crest of a calcarenite cuesta, overlaying a layer of these sands. When the collapsible sand is dry, the structure is strong enough to bond the sand particles together. When the sand becomes wet, a de-structuration mechanism occurs and the soil’s strength is compromised. This paper has a twofold aim…

Use of potassium polyaspartate for the tartaric stabilization of Sicilian white wines

2019

Cold stabilization is a common method used to avoid tartaric acid crystals from forming in bottled wine, but this technique shows some inconveniences on the sensory characteristics and energy cost. In the present research, the tartaric stabilization in Sicilian white wines, with a recently permissible molecule in oenology, was studied: the potassium polyaspartate (PAK). The PAK has a negative charge at wine pH and allows to sequester the K+ cations; consequently it inhibits the formation and the growth of potassium bitartrate crystals. PAK is a relatively small polymer; perfectly microfiltrated and does not allow the filling phenomena in filtration membranes. The adding of PAK allowed to re…

Pre-Analytical Determination of the Effect of Extended Warm or Cold Ischaemia on RNA Stability in the Human Ileum Mucosa

2015

The use of banked human tissue, obtained with informed consent after elective surgical procedures, represents a powerful model for understanding underlying mechanisms of diseases or therapeutic interventions and for establishing prognostic markers. However, donated tissues typically have varying times of warm ischaemia in situ due to blood arrest or cold ischaemia due to procurement and transportation. Hence, before using these tissues, it is important to carry out pre-analytical studies to ensure that they are representative of the in vivo state. In particular, tissues of the gastrointestinal tract have been thought to have low RNA stability. Therefore, this study aimed to determine if ext…

Functional regulation of HIF-1α under normoxia--is there more than post-translational regulation?

2011

The hypoxia-inducible factor-1 (HIF-1) is an oxygen-regulated transcriptional activator playing a pivotal role in mammalian physiology and disease pathogenesis, e.g., HIF-1 is indispensable in a broad range of developmental stages in different tumors. Its post-translational regulation via PHDs under the influence of hypoxia is widely investigated and accepted. Different non-hypoxic stimuli such as lipopolysaccharides (LPS), thrombin, and angiotensin II (Ang II), have been proven to enhance HIF-1 levels through activation of regulative mechanisms distinct from protein stabilization. Some of these stimuli specifically regulate HIF-1α at the transcriptional, post-transcriptional, or translatio…

Jute bioblanket as a soil rehabilitation strategy in Sorocaba, Brazil: Soil chemistry and SWOT approaches

2019

Made available in DSpace on 2022-04-29T08:28:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-01 Soil erosion and the invasion of exotic plant species are major constraints to achieve sustainable development around the world. Currently, we find few products devoted concomitantly to combatting soil erosion as well as the establishment of unwanted exotic plants. In this paper, we introduce a new product, called herein a bioblanket, that protects the soil and impedes the establishment of exotic plant species. This product is of simple design, and to manufacture it, we use two biodegradable materials: jute tissue and grass wastes. We designed this product to combat soil erosion and …

Infinite coordination polymer networks metallogelation of aminopyridine conjugates and in situ silver nanoparticle formation

2018

Herein we report silver(i) directed infinite coordination polymer network (ICPN) induced self-assembly of low molecular weight organic ligands leading to metallogelation. Structurally simple ligands are derived from 3-aminopyridine and 4-aminopyridine conjugates which are composed of either pyridine or 2,2'-bipyridine cores. The cation specific gelation was found to be independent of the counter anion, leading to highly entangled fibrillar networks facilitating the immobilization of solvent molecules. Rheological studies revealed that the elastic storage modulus (G') of a given gelator molecule is counter anion dependent. The metallogels derived from ligands containing a bipyridine core dis…