scholarly journals Advanced Protection Against Marine Biofouling Using Solar Light

2017 ◽  
Author(s):  
Gabriele Scandura ◽  
Rosaria Ciriminna ◽  
Lütfiye Yıldız Ozer ◽  
Francesco Meneguzzo ◽  
Giovanni Palmisano ◽  
...  

AbstractWe undertook prolonged testing of a new xerogel coating (AquaSun) to protect from marine biofouling a surface probe immersed in the seawater of Abu Dhabi. Electron microscopy, Raman mapping, and photoluminescence experiments coupled to extensive analyses of marine water before and after 122 days of testing showed excellent action against biofouling when irradiating the probe with visible light. Considering the high chemical and mechanical stability and the low cost of the sol-gel coating, the technology has significant potential en route to replacing conventional antifouling and foul release coatings with a single product of broad applicability.

2016 ◽  
Vol 74 (8) ◽  
pp. 1936-1945 ◽  
Author(s):  
Zhengshan Cui ◽  
Wanxia He ◽  
Jun Liu ◽  
Wei Wei ◽  
Liang Jiang ◽  
...  

Through sol-gel and dip-coating processes, commercial polyurethane sponge modified by polysiloxane was fabricated under low temperature (60 °C) and atmosphere. The contact angle of the obtained polysiloxane/polyurethane sponge is 145 ± 5°. Hence, the polysiloxane/polyurethane sponge could float on water and selectively absorb organics from the surface of the water, indicating simultaneous properties of hydrophobicity and oleophilicity. The absorbent maximum value is 50–150 times of its own weight. The polysiloxane/polyurethane sponge exhibited excellent recyclability, which could be reused by squeezing the sponge due to its high mechanical stability and flexibility. Thermogravimetry-differential thermal analysis test indicated that the polysiloxane/polyurethane sponge exhibited good thermal stability and the stable contact angle of samples tested under increasing temperature indicated its good weather resistance. Due to the commercial property of polyurethane sponge and easy-handling of polysiloxane, the polysiloxane/polyurethane sponge can be easily scaled up to recover a large-area oil spill in water and further work based on the designed equipment has been under consideration.


2021 ◽  
pp. 104687812110326
Author(s):  
Adeel Arif ◽  
Amber Arif ◽  
Kimberly Anne Fasciglione ◽  
Farrukh Nadeem Jafri

Abstract: Background Locations concentrated with High School (HS) students tend to have lower out-of-hospital cardiac arrest (OHCA) survival rates. Mobile applications (apps) have the capability to augment cardiopulmonary resuscitation (CPR) skill retention as a low-cost, accessible training method. Methods An iterative process to develop an app to reinforce CPR skills emphasizing hand placement, compression rate, real-time feedback, and recurring tips is described. The app was tested on HS students to measure its impact on quality and comfort of CPR using Likert surveys and skills assessments before and after one month of usage. CPR Score and compression rate were measured using the Laerdal™ Little Anne Manikin QCPR software. Results Fourteen HS students participated in a prospective observational study. It was found that the use of the developed app was associated with improved CPR performance (80.43% v. 87.86%, p=0.01-0.02, 95% CI=2.20-12.66) after one month. Additionally, improvements were demonstrated in compression rate accuracy (21.43% v. 64.29%, p=0.041, 95% CI=0.132-0.725), increased comfort performing CPR (3.86 v. 4.79, p<0.001, 95% CI =0.99-1.00) and comfort performing CPR on strangers (2.71 v. 4.42, p<0.001, 95% CI=1.24-2.19). In addition, for every time the app was used, CPR performance increased by 0.5668% (p=0.0182). Conclusion Findings suggest that mobile apps may have promising implications as augmentative tools for CPR curriculums.


RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.


Landslides ◽  
2021 ◽  
Author(s):  
Lorenzo Brezzi ◽  
Alberto Bisson ◽  
Davide Pasa ◽  
Simonetta Cola

AbstractA large number of landslides occur in North-Eastern Italy during every rainy period due to the particular hydrogeological conditions of this area. Even if there are no casualties, the economic losses are often significant, and municipalities frequently do not have sufficient financial resources to repair the damage and stabilize all the unstable slopes. In this regard, the research for more economically sustainable solutions is a crucial challenge. Floating composite anchors are an innovative and low-cost technique set up for slope stabilization: it consists in the use of passive sub-horizontal reinforcements, obtained by coupling a traditional self-drilling bar with some tendons cemented inside it. This work concerns the application of this technique according to the observational method described within the Italian and European technical codes and mainly recommended for the design of geotechnical works, especially when performed in highly uncertain site conditions. The observational method prescribes designing an intervention and, at the same time, using a monitoring system in order to correct and adapt the project during realization of the works on the basis of new data acquired while on site. The case study is the landslide of Cischele, a medium landslide which occurred in 2010 after an exceptional heavy rainy period. In 2015, some floating composite anchors were installed to slow down the movement, even if, due to a limited budget, they were not enough to ensure the complete stabilization of the slope. Thanks to a monitoring system installed in the meantime, it is now possible to have a comparison between the site conditions before and after the intervention. This allows the evaluation of benefits achieved with the reinforcements and, at the same time, the assessment of additional improvements. Two stabilization scenarios are studied through an FE model: the first includes the stabilization system built in 2015, while the second evaluates a new solution proposed to further increase the slope stability.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1099
Author(s):  
Ye-Ji Han ◽  
Se Hyeong Lee ◽  
So-Young Bak ◽  
Tae-Hee Han ◽  
Sangwoo Kim ◽  
...  

Conventional sol-gel solutions have received significant attention in thin-film transistor (TFT) manufacturing because of their advantages such as simple processing, large-scale applicability, and low cost. However, conventional sol-gel processed zinc tin oxide (ZTO) TFTs have a thermal limitation in that they require high annealing temperatures of more than 500 °C, which are incompatible with most flexible plastic substrates. In this study, to overcome the thermal limitation of conventional sol-gel processed ZTO TFTs, we demonstrated a ZTO TFT that was fabricated at low annealing temperatures of 350 °C using self-combustion. The optimized device exhibited satisfactory performance, with μsat of 4.72 cm2/V∙s, Vth of −1.28 V, SS of 0.86 V/decade, and ION/OFF of 1.70 × 106 at a low annealing temperature of 350 °C for one hour. To compare a conventional sol-gel processed ZTO TFT with the optimized device, thermogravimetric and differential thermal analyses (TG-DTA) and X-ray photoelectron spectroscopy (XPS) were implemented.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1184
Author(s):  
Maria Cantarella ◽  
Giuliana Impellizzeri ◽  
Alessandro Di Mauro ◽  
Vittorio Privitera ◽  
Sabrina Carola Carroccio

The immobilization of inorganic nanomaterials on polymeric substrates has been drawing a lot of attention in recent years owing to the extraordinary properties of the as-obtained materials. The hybrid materials, indeed, combine the benefits of the plastic matter such as flexibility, low-cost, mechanical stability and high durability, with them deriving from their inorganic counterparts. In particular, if the inorganic fillers are nanostructured photocatalysts, the originated hybrid systems will be able to utilize the energy delivered by light, catalysing chemical reactions in a sustainable pathway. Most importantly, since the nanofillers can be ad-hoc anchored to the macromolecular structure, their release in the environment will be prevented, thus overcoming one of the main restrictions that impedes their applications on a large scale. In this review, several typologies of hybrid photocatalytic nanomaterials, obtained by using both organic and inorganic semiconductors and realized with different synthetic protocols, were reported and discussed. In the first part of the manuscript, nanocomposites realized by simply blending the TiO2 or ZnO nanomaterials in thermoplastic polymeric matrices are illustrated. Subsequently, the atomic layer deposition (ALD) technique is presented as an excellent method to formulate polymeric nanocomposites. Successively, some examples of polyporphyrins hybrid systems containing graphene, acting as photocatalysts under visible light irradiation, are discussed. Lastly, photocatalytic polymeric nanosponges, with extraordinary adsorption properties, are shown. All the described materials were deeply characterized and their photocatalytic abilities were evaluated by the degradation of several organic water pollutants such as dyes, phenol, pesticides, drugs, and personal care products. The antibacterial performance was also evaluated for selected systems. The relevance of the obtained results is widely overviewed, opening the route for the application of such multifunctional photocatalytic hybrid materials in wastewater remediation.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 500-510
Author(s):  
Xiaoguang Ying ◽  
Jieyuan He ◽  
Xiao Li

Abstract An imprinted electrospun fiber membrane was developed for the detection of volatile organic acids, which are key components of human body odor. In this study, hexanoic acid (HA) was selected as the target, polymethyl methacrylate (PMMA) was used as the substrate, and colorimetric detection of HA was achieved by a bromocresol purple (BCP) chromogenic agent. The results showed that the morphology of the fiber membrane was uniform and continuous, and it showed excellent selectivity and specificity to HA. Photographs of the color changes before and after fiber membrane adsorption were recorded by a camera and quantified by ImageJ software by the difference in gray value (ΔGray). This method is simple, intuitive, and low cost and has great potential for application in human odor analysis.


2005 ◽  
Vol 885 ◽  
Author(s):  
Krithi Shetty ◽  
Shihuai Zhao ◽  
Wei Cao ◽  
Naidu V. Seetala ◽  
Debasish Kuila

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.


2016 ◽  
Vol 49 (6) ◽  
pp. 685-716 ◽  
Author(s):  
Jamie Anderson ◽  
Kai Ruggeri ◽  
Koen Steemers ◽  
Felicia Huppert

Empirical urban design research emphasizes the support in vitality of public space use. We examine the extent to which a public space intervention promoted liveliness and three key behaviors that enhance well-being (“connect,” “be active,” and “take notice”). The exploratory study combined directly observed behaviors with self-reported, before and after community-led physical improvements to a public space in central Manchester (the United Kingdom). Observation data ( n = 22,956) and surveys (subsample = 212) were collected over two 3-week periods. The intervention brought significant and substantial increases in liveliness of the space and well-being activities. None of these activities showed increases in a control space during the same periods. The findings demonstrate the feasibility of the research methods, and the impact of improved quality of outdoor neighborhood space on liveliness and well-being activities. The local community also played a key role in conceiving of and delivering an effective and affordable intervention. The findings have implications for researchers, policy makers, and communities alike.


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