barrier effects
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Author(s):  
C. Pandian ◽  
A.Abdul Hasan Sathali ◽  
G. Abirami ◽  
E. Krithika

Psoriasis is a chronic condition that is caused by the negative signals given by immune system, which leads to hyperproliferation and other inflammatory reactions on the skin. These conditions may adversely affect the quality of the patient’s life leading to psychological stress. Topical delivery of drug is always preferred for Psoriasis because other treatments may lead to systemic intoxication and other adverse reactions. Triamcinolone is a topical corticosteroid belonging to BCS class IV (low solubility and permeability) used to treat Psoriasis. The limitations with transdermal delivery is that only a small amount of the drug can be transferred through the skin tissue due to the barrier effects of the Stratum corneum. Therefore, Novel transdermal delivery system, Cubosomes belonging to Nanostructured lipid carriers were chosen to overcome the issues of solubility and permeability. Twelve formulations were prepared with various ratios of Glyceryl monooleate (2.5 to 5%) & Poloxamer 407 (0.5 to 2%) and the formulations were evaluated for particle size, PDI, zeta potential, entrapment efficacy, drug content and in-vitro release. The best composition of Cubosomes was selected and incorporated into transdermal patch and the formulated patches were evaluated.


2021 ◽  
pp. 136365
Author(s):  
Bin He ◽  
Liyuan Wang ◽  
Shuang Li ◽  
Fuyuan Cao ◽  
Lei Wu ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 987
Author(s):  
Gabrielle Dublet-Adli ◽  
Thomas Pabst ◽  
Gudny Okkenhaug ◽  
Christian Sætre ◽  
Anna M. Vårheim ◽  
...  

The reclamation of acid-generating mine tailings typically involves building cover systems to limit interactions with water or oxygen. The choice of cover materials is critical to ensure long-term performance, and partly determines the environmental footprint of the reclamation strategy. The objective of this research was to evaluate if tailings pre-oxidized on-site could be used in cover systems. Column experiments were performed to assess the effectiveness of a cover with capillary barrier effects (CCBE), where the moisture retention layer (MRL) was made of pre-oxidized tailings with little to no remaining sulfides (LS tailings). The columns were submitted to regular wetting and drying cycles, and their hydrological and geochemical behaviour was monitored for 510 days. The LS tailings showed satisfying hydrological properties as an MRL and remained saturated throughout the test. The concentrations of Cu in the drainage decreased by more than two orders of magnitude compared to non-covered tailings. In addition, the pH increased by nearly one unit compared to the control column, and Fe and S concentrations decreased by around 50%. Despite these improvements, the leachate water remained acidic and contaminated, indicating that acid drainage continued to be generated despite a hydrologically efficient CCBE.


2021 ◽  
Vol 12 (3) ◽  
pp. 152
Author(s):  
Keith Chamberlain ◽  
Salah Al Majeed

For electric vehicles (EVs) to realise the UK government’s goal of mass-market dominance, there are surmountable hurdles to resolve before car users accept this radical shift in motoring technology. This study focuses on recent EV adopters who experience a new phenomenon described as charge point trauma (CPT). In contrast to range anxiety, we define CPT as the psychological, physiological, and behavioural condition where EV user’s experiences develop trauma or anxiety in response to the availability of sufficient charge points, locations, payment processes, and operability. Resolving impediments to EV usage reduces long-term growth barriers, which we argue can subsequently lower or even eliminate EV driver anxiety. We conclude that range anxiety still plays a major part in overall EV driver trauma, and after deep analysis of our case study data conclude that a trauma other than range anxiety exists at the charge point. To mitigate this phenomenon, we propose a regulatory framework comprising a series of stimuli to encourage EV uptake. These recommendations should be targeted at regulating a new generation of EV charging stations to meet operational parity with current fossil fuel filling stations by ensuring they are always on, available in sufficient numbers, accessible and operable as part of the UK motorway and major trunk network. This will de-risk EV purchasing and stimulate their adoption in this embryonic stage, reducing CPT in the process.


2021 ◽  
Author(s):  
Henry D. Kunerth ◽  
Steve M. Bogdanowicz ◽  
Jeremy B. Searle ◽  
Richard G. Harrison ◽  
Brad S. Coates ◽  
...  

ABSTRACTTheory predicts that when different barriers to gene flow become coincident, their joint effects enhance reproductive isolation and genomic divergence beyond their individual effects, but empirical tests of this ‘coupling’ hypothesis are rare. Here, we analyze patterns of gene exchange among populations of European corn borer moths that vary in the number of acting barriers, allowing for comparisons of genomic variation when barrier traits or loci are in coincident or independent states. We find that divergence is mainly restricted to barrier loci when populations differ by a single barrier, whereas the coincidence of temporal and behavioral barriers is associated with divergence of two chromosomes harboring barrier loci. Furthermore, differentiation at temporal barrier loci increases in the presence of behavioral divergence, while differentiation at behavioral barrier loci increases in the presence of temporal divergence. Our results demonstrate how the joint action of coincident barrier effects leads to levels of genomic differentiation that far exceed those of single barriers acting alone, consistent with theory arguing that coupling allows indirect selection to combine with direct selection and thereby lead to a stronger overall barrier to gene flow. Thus, the state of barriers – independent or coupled – strongly influences the accumulation of genomic differentiation.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 657
Author(s):  
Sherif S. M. Ghoneim ◽  
Sobhy S. Dessouky ◽  
Ahmed Boubakeur ◽  
Adel A. Elfaraskoury ◽  
Ahmed B. Abou Sharaf ◽  
...  

In modern power systems, power transformers are considered vital components that can ensure the grid’s continuous operation. In this regard, studying the breakdown in the transformer becomes necessary, especially its insulating system. Hence, in this study, Box–Behnken design (BBD) was used to introduce a prediction model of the breakdown voltage (VBD) for the transformer insulating oil in the presence of different barrier effects for point/plane gap arrangement with alternating current (AC) voltage. Interestingly, the BBD reduces the required number of experiments and their costs to examine the barrier parameter effect on the existing insulating oil VBD. The investigated variables were the barrier location in the gap space (a/d)%, the relative permittivity of the barrier materials (εr), the hole radius in the barrier (hr), the barrier thickness (th), and the barrier inclined angle (θ). Then, only 46 experiment runs are required to build the BBD model for the five barrier variables. The BBD prediction model was verified based on the statistical study and some other experiment runs. Results explained the influence of the inclined angle of the barrier and its thickness on the VBD. The obtained results indicated that the designed BBD model provides less than a 5% residual percentage between the measured and predicted VBD. The findings illustrated the high accuracy and robustness of the proposed insulating oil breakdown voltage predictive model linked with diverse barrier effects.


2021 ◽  
Author(s):  
Estanislao Pujades

Impervious structures below the water table modify the natural groundwater flow in aquifers. They act as barriers, causing heads to rise upgradient and to fall downgradient. We define the barrier effect as the increase in head loss across the barrier with respect to the natural conditions prior to construction. We distinguish between regional (the minimum head loss observed at long distances) and local (the maximum head loss observed close to the structure) barrier effects. We use numerical and analytical methods to derive semi-empirical equations to quantify the two barrier effects for semi-permeable, partially penetrating (or fully penetrating but finite in length), and barriers with a by-pass in confined aquifers. The resulting equations depend on the barrier geometry and on the natural head gradient in the aquifer and they are easy to apply. We test their validity at two construction sites, obtaining excellent agreement between the computed and observed barrier effects.


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