scholarly journals Highly rough surface coatings via the ambient temperature deposition of thermosetting polymers

2019 ◽  
Vol 7 (13) ◽  
pp. 7333-7337 ◽  
Author(s):  
Yasmin A. Mehanna ◽  
Rebekah L. Upton ◽  
Colin R. Crick

A new materials fabrication approach that facilitates the heat curing of thermosetting polymers, while depositing a film at room temperature.

Author(s):  
S. Mahajan

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.


2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>


2014 ◽  
Vol 70 (a1) ◽  
pp. C984-C984
Author(s):  
Alessia Bacchi ◽  
Davide Capucci ◽  
Paolo Pelagatti

The objective of this work is to embed liquid or volatile pharmaceuticals inside crystalline materials, in order to tune their delivery properties in medicine or agrochemistry, and to explore new regulatory and intellectual properties issues. Liquid or volatile formulations of active pharmaceutical ingredients (APIs) are intrinsically less stable and durable than solid forms; in fact most drugs are formulated as solid dosage because they tend to be stable, reproducible, and amenable to purification. Most drugs and agrochemicals are manufactured and distributed as crystalline materials, and their action involves the delivery of the active molecule by a solubilization process either in the body or on the environment. However some important compounds for the human health or for the environment occur as liquids at room temperature. The formation of co-crystals has been demonstrated as a means of tuning solubility properties of solid phases, and therefore it is widely investigated by companies and by solid state scientists especially in the fields of pharmaceuticals, agrochemicals, pigments, dyestuffs, foods, and explosives. In spite of this extremely high interest towards co-crystallization as a tool to alter solubility, practically no emphasis has been paid to using it as a means to stabilize volatile or labile or low-melting products. In this work we trap and stabilize volatile and liquid APIs and agrochemicals in crystalline matrices by engineering suitable co-crystals. These new materials alter the physic state of the active ingredients allowing to expand the phase space accessible to manufacturing and delivery. We have defined a benchmark of molecules relevant to human health and environment that have been combined with suitable partners according to the well known methods of crystal engineering in order to obtain cocrystals. The first successful results will be discussed; the Figure shows a cocrystal of propofol, a worldwide use anesthetic.


APL Materials ◽  
2018 ◽  
Vol 6 (7) ◽  
pp. 076107 ◽  
Author(s):  
Tomas Polakovic ◽  
Sergi Lendinez ◽  
John E. Pearson ◽  
Axel Hoffmann ◽  
Volodymyr Yefremenko ◽  
...  

2014 ◽  
Vol 70 (a1) ◽  
pp. C1101-C1101
Author(s):  
Laurent Castro ◽  
Nicolas Penin ◽  
Dany Carlier ◽  
Alain Wattiaux ◽  
Stanislav Pechev ◽  
...  

Iron vanadates and phosphates have been widely explored [1-2] as possible electrode material for Li-ion batteries. In the goal of finding new materials, our approach was to consider existing materials and to investigate the flexibility of their network for possible substitutions. Among the different materials containing iron and vanadium, Cu3Fe4(XO4)6 (X = P, V) are isostructural to Fe7(PO4)6. Lafontaine et al. [3] discussed the structural relationships between β-Cu3Fe4(VO4)6 and several other vanadates, phosphates and molybdates of general formula AxBy(VO4)6. The interesting network flexibility was then demonstrated with the existence of four different crystallographic sites, which can be partially occupied depending on the x+y value : x+y = 7 for β-Cu3Fe4(VO4)6) and x+y = 8 for NaCuFe2(VO4)3. The LixFey(VO4)6 phase was then prepared considering the substitution of Li+ and Fe3+ for Cu2+ ions in β-Cu3Fe4(VO4)6 and the existence of an extra site to accommodate the charge compensation (7 ≤ x+y ≤ 8). As expected, a new lithium iron vanadate, isotructural to mineral Howardevansite was then obtained. Single crystal diffraction data were collected at room temperature on Enraf-Nonius CAD-4 diffractometer. Structure was refined with JANA-2006 program package. Mössbauer and magnetic measurements were also used to check the oxidation state of iron ions, to support the obtained crystal structure and to consider any possible structural/magnetic transitions. All the results will be presented and discussed in this presentation.


Author(s):  
Wuttichai Phae-ngam ◽  
Tossaporn Lertvanithphol ◽  
Chanunthorn Chananonnawathorn ◽  
Rattanachai Kowong ◽  
Mati Horprathum ◽  
...  

2021 ◽  
Vol 105 (1) ◽  
pp. 119-134
Author(s):  
Jana Zimáková ◽  
Petr Baca ◽  
Martin Langer ◽  
Tomáš Binar

This work deals with lead-acid batteries, their properties and individual types that are available on the market. The temperature dependences of the battery parameters at different ambient temperatures and at different discharging and charging modes are measured. 6 batteries are tested at different charging currents, which provides information about their behavior both during discharge and at the time of charging. During the experiments, testing is not only performed at room temperature, but the batteries are also exposed to high temperatures up to 75 °C.


2019 ◽  
pp. 57-68

“Solo” papaya fruits were harvested in October, 2016 & 2017 seasons from a commercial orchard located in Ismailia Governorate, Egypt. Papaya fruits were harvested at three maturity stages: 25% yellow (stage 1), 50% yellow (stage 2) and 100% yellow (stage 3) and evaluated during storage at ambient temperature (20°C ± 2) for 4 days + at 80- 85% RH or during cold storage at 6°C + 90- 95% RH for 20 days. Papaya fruits softened very rapidly at room temperature after harvest and had 4 days shelf life. However, the fruit can be stored for 20 days at 6°C with little changes in firmness and the fruit apparently progressed in normal ripening upon removal to ambient temperature (20°C) for 3 days. All colour values (a*, L* and C*) were linearly increased during cold storage. Conversely, as a result of colour change from green to orange-red, h° values decreased. Soluble solids content was not affected during ripening at 20°C and remained steady. Fruit harvested at stage 2 and stored at 6°C for 20 days following 3 days at 20°C had superior score for sensorial evaluation.


Sign in / Sign up

Export Citation Format

Share Document