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10th Anniversary of Applied Sciences-Invited Papers in Chemistry Section

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Chemical and Molecular Sciences".

Deadline for manuscript submissions: closed (31 December 2020) | Viewed by 43888

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A printed edition of this Special Issue is available here.

Special Issue Editor

Special Issue Information

Dear Colleagues,

Applied Sciences has reached a remarkable milestone this year by publishing its 10th volume of the journal, and to celebrate this special occasion, we have launched a special issue devoted to Chemistry entitled “The 10th Anniversary of Applied Sciences—Invited Papers in the Chemistry Section”.

This Special Issue will consist of comprehensive review and original research articles featuring important and recent developments or advabcements in all areas of chemisty. Authors who are well-known experts in their fields of study are invited to submit their contributions for this Special Issue up to the end of November 2020. The submitted papers can cover either experimental or theoretical aspects, or both, of all branches of chemistry and its subdisciplines. These also include research on how chemsitry is used for various applications in modern society. Subject areas include (but are not limited to): analytical chemistry, electrochemistry, environmental chemistry, inorganic chemistry, organic chemistry, physical chemistry, materials chemistry, etc. More details can be found at:

https://www.mdpi.com/journal/applsci/sections/applied_chemistry

We invite you to contribute a comprehensive review article or an original research paper for peer-review and possible publication in this Special Issue to commemorate the publication this year of the 10th volume of Applied Sciences.

Prof. Dr. Samuel Adeloju
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (14 papers)

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Editorial

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4 pages, 186 KiB  
Editorial
10th Anniversary of Applied Sciences-Invited Papers in Chemistry Section
by Samuel B. Adeloju
Appl. Sci. 2021, 11(6), 2831; https://doi.org/10.3390/app11062831 - 22 Mar 2021
Viewed by 1169
Abstract
MDPI´s Applied Sciences reached a remarkable milestone in 2020 when the 10th volume of the journal was published and an impact factor of 2 [...] Full article

Research

Jump to: Editorial, Review

17 pages, 1464 KiB  
Article
Weekly and Longitudinal Element Variability in Hair Samples of Subjects Non-Occupationally Exposed
by Pasquale Avino, Monica Lammardo, Andrea Petrucci and Alberto Rosada
Appl. Sci. 2021, 11(3), 1236; https://doi.org/10.3390/app11031236 - 29 Jan 2021
Cited by 3 | Viewed by 2788
Abstract
Hair is an ideal tissue for tracing the human health conditions. It can be cut easily and painlessly, and the relative clinical results can give an indication of mineral status and toxic metal accumulation following long-term or even acute exposure. Different authors have [...] Read more.
Hair is an ideal tissue for tracing the human health conditions. It can be cut easily and painlessly, and the relative clinical results can give an indication of mineral status and toxic metal accumulation following long-term or even acute exposure. Different authors have found outdoor pollution phenomena, such as the levels, significantly alter metal and metalloid hair contents. This paper investigates the element concentration variability in hair samples collected from a not-exposed teenager, neither environmentally nor professionally. The sampling was carried out for one week, and the samples were collected from different locations on the scalp. A nuclear analytical methodology, i.e., the Instrumental Neutron Activation Analysis, is used for determining about 30 elements. Some differences have been found among the samplings as well as between the proximal and distal sections. A deep comparison with other similar studies worldwide present in the literature has been performed for evidencing the relationships and the differences due to different ethnical origins, lifestyles, diets, and climates among the different young populations. Full article
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15 pages, 3265 KiB  
Article
Fast and Low-Cost Synthesis of MoS2 Nanostructures on Paper Substrates for Near-Infrared Photodetectors
by Neusmar J. A. Cordeiro, Cristina Gaspar, Maria J. de Oliveira, Daniela Nunes, Pedro Barquinha, Luís Pereira, Elvira Fortunato, Rodrigo Martins, Edson Laureto and Sidney A. Lourenço
Appl. Sci. 2021, 11(3), 1234; https://doi.org/10.3390/app11031234 - 29 Jan 2021
Cited by 20 | Viewed by 3941
Abstract
Recent advances in the production and development of two-dimensional transition metal dichalcogenides (2D TMDs) allow applications of these materials, with a structure similar to that of graphene, in a series of devices as promising technologies for optoelectronic applications. In this work, molybdenum disulfide [...] Read more.
Recent advances in the production and development of two-dimensional transition metal dichalcogenides (2D TMDs) allow applications of these materials, with a structure similar to that of graphene, in a series of devices as promising technologies for optoelectronic applications. In this work, molybdenum disulfide (MoS2) nanostructures were grown directly on paper substrates through a microwave-assisted hydrothermal synthesis. The synthesized samples were subjected to morphological, structural, and optical analysis, using techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman. The variation of synthesis parameters, as temperature and synthesis time, allowed the manipulation of these nanostructures during the growth process, with alteration of the metallic (1T) and semiconductor (2H) phases. By using this synthesis method, two-dimensional MoS2 nanostructures were directly grown on paper substrates. The MoS2 nanostructures were used as the active layer, to produce low-cost near-infrared photodetectors. The set of results indicates that the interdigital MoS2 photodetector with the best characteristics (responsivity of 290 mA/W, detectivity of 1.8 × 109 Jones and external quantum efficiency of 37%) was obtained using photoactive MoS2 nanosheets synthesized at 200 °C for 120 min. Full article
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19 pages, 5832 KiB  
Article
The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials
by Irene A. Kanellopoulou, Ioannis A. Kartsonakis and Costas A. Charitidis
Appl. Sci. 2021, 11(2), 700; https://doi.org/10.3390/app11020700 - 13 Jan 2021
Cited by 11 | Viewed by 2403
Abstract
Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of [...] Read more.
Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized. Full article
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23 pages, 1655 KiB  
Article
Preparation and Characterization of Licorice-Chitosan Coatings for Postharvest Treatment of Fresh Strawberries
by Somaris E. Quintana, Olimpia Llalla, Luis A. García-Zapateiro, Mónica R. García-Risco and Tiziana Fornari
Appl. Sci. 2020, 10(23), 8431; https://doi.org/10.3390/app10238431 - 26 Nov 2020
Cited by 15 | Viewed by 4082
Abstract
Several plant extracts are being investigated to produce edible coatings, mainly due to their antioxidant and antimicrobial activities. In this study, licorice root extracts were produced by ultrasound-assisted extraction and were combined with chitosan to elaborate edible coatings. Different solvents and temperatures were [...] Read more.
Several plant extracts are being investigated to produce edible coatings, mainly due to their antioxidant and antimicrobial activities. In this study, licorice root extracts were produced by ultrasound-assisted extraction and were combined with chitosan to elaborate edible coatings. Different solvents and temperatures were used in the extraction process, and the antioxidant and antimicrobial activity of the extracts were assessed. The most bioactive extracts were selected for the development of the edible coatings. The rheological properties of the coatings were studied, and they were applied on strawberry to evaluate their physicochemical and microbiological properties. The addition of licorice extract to chitosan resulted in positive effects on the rheological properties of the coatings: the incorporation of phytochemicals to chitosan decreased the shear stress and improved the restructuring ability of the coating solutions. The films presented a reduction of the Burger model parameter, indicating a reduction of rigidity. Furthermore, the strawberry coated with chitosan and licorice extract maintained good quality parameters during storage and showed the best microbiological preservation in comparison with controls. Hence, the use of chitosan with licorice extract is a potential strategy to produce edible coating for improving the postharvest quality of fruits. Full article
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13 pages, 3944 KiB  
Article
Hydrothermal Synthesis of ZnO–doped Ceria Nanorods: Effect of ZnO Content on the Redox Properties and the CO Oxidation Performance
by Sofia Stefa, Maria Lykaki, Vasillios Binas, Pavlos K. Pandis, Vassilis N. Stathopoulos and Michalis Konsolakis
Appl. Sci. 2020, 10(21), 7605; https://doi.org/10.3390/app10217605 - 28 Oct 2020
Cited by 14 | Viewed by 2498
Abstract
The rational design of highly efficient, noble metal-free metal oxides is one of the main research priorities in the area of catalysis. To this end, the fine tuning of ceria-based mixed oxides by means of aliovalent metal doping has currently received particular attention [...] Read more.
The rational design of highly efficient, noble metal-free metal oxides is one of the main research priorities in the area of catalysis. To this end, the fine tuning of ceria-based mixed oxides by means of aliovalent metal doping has currently received particular attention due to the peculiar metal-ceria synergistic interactions. Herein, we report on the synthesis, characterization and catalytic evaluation of ZnO–doped ceria nanorods (NR). In particular, a series of bare CeO2 and ZnO oxides along with CeO2/ZnO mixed oxides of different Zn/Ce atomic ratios (0.2, 0.4, 0.6) were prepared by the hydrothermal method. All prepared samples were characterized by X-ray diffraction (XRD), N2 physisorption, temperature-programmed reduction (TPR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The CO oxidation reaction was employed as a probe reaction to gain insight into structure-property relationships. The results clearly showed the superiority of mixed oxides as compared to bare ones, which could be ascribed to a synergistic ZnO–CeO2 interaction towards an improved reducibility and oxygen mobility. A close correlation between the catalytic activity and oxygen storage capacity (OSC) was disclosed. Comparison with relevant literature studies verifies the role of OSC as a key activity descriptor for reactions following a redox-type mechanism. Full article
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13 pages, 1395 KiB  
Article
Decomposition of Flavonols in the Presence of Saliva
by Malgorzata Rogozinska and Magdalena Biesaga
Appl. Sci. 2020, 10(21), 7511; https://doi.org/10.3390/app10217511 - 26 Oct 2020
Cited by 12 | Viewed by 2285
Abstract
In this study, the LC-MS/MS was applied to explore the stability of four common dietary flavonols, kaempferol, quercetin, isorhamnetin, and myricetin, in the presence of hydrogen peroxide and saliva. In addition, the influence of saliva on the representative quercetin glycosides, rutin, quercitrin, hyperoside, [...] Read more.
In this study, the LC-MS/MS was applied to explore the stability of four common dietary flavonols, kaempferol, quercetin, isorhamnetin, and myricetin, in the presence of hydrogen peroxide and saliva. In addition, the influence of saliva on the representative quercetin glycosides, rutin, quercitrin, hyperoside, and spiraeoside was examined. Our study showed that, regardless of the oxidative agent used, flavonols stability decreases with increasing B-ring substitution. The decomposition of analyzed compounds was based on their splitting by the opening the heterocyclic C-ring and realizing more simple aromatic compounds. The dead-end products corresponded to different benzoic acid derivatives derived from B-ring. Kaempferol, quercetin, isorhamnetin, and myricetin were transformed into 4-hydroxybeznoic acid, protocatechuic acid, vanillic acid, and gallic acid, respectively. Additionally, for quercetin and myricetin, two intermediate depsides and 2,4,6-trihydroxybenzoic acid derived from A-ring were detected. All analyzed glycosides were resistant to hydrolysis in the presence of saliva. Based on our data, saliva was proven to be a next oxidative agent which leads to the formation of corresponding phenolic acids. Hence, studies on flavonols’ metabolism should take into consideration that the flavonols decomposition starts in the oral cavity; hence, in subsequent parts of the human digestive tract, they could be present not in their parent form but as phenolic acids. Further analyses of the influence of saliva on flavonols glycosides need to be performed due to the possible interindividual fluctuations. Full article
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10 pages, 1677 KiB  
Communication
Use of a Mixed Cationic-Reverse Phase Column for Analyzing Small Highly Polar Metabolic Markers in Biological Fluids for Multiclass LC-HRMS Method
by Marco Roverso, Iole Maria Di Gangi, Gabriella Favaro, Paolo Pastore and Sara Bogialli
Appl. Sci. 2020, 10(20), 7137; https://doi.org/10.3390/app10207137 - 14 Oct 2020
Cited by 1 | Viewed by 1708
Abstract
The determination of small highly polar metabolites at low concentrations is challenging when reverse-phase (RP) chromatography is used for multiclass analysis. A mixed cationic-RP column coupled to high-resolution tandem MS (HR-MS/MS) was tested for highly polar compounds in biological fluids, i.e., trimethylamine N-oxide [...] Read more.
The determination of small highly polar metabolites at low concentrations is challenging when reverse-phase (RP) chromatography is used for multiclass analysis. A mixed cationic-RP column coupled to high-resolution tandem MS (HR-MS/MS) was tested for highly polar compounds in biological fluids, i.e., trimethylamine N-oxide (TMAO) and the isobaric molecules beta-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB). The efficient retention and separation of the above compounds were obtained with common and MS-friendly RP conditions, reaching high selectivity and sensitivity. The method was firstly assessed in plasma and urine, showing good linearity in the range 50–1000 µg/L and 500–10,000 µg/L for TMAO and both BMAA and DAB, respectively. Excellent precision (RDS < 3%) and good accuracies (71–85%) were observed except for BMAA in plasma, whose experimental conditions should be specifically optimized. Preliminary tests performed on compounds with biological relevance and a wider range of polarities proved the effectiveness of this chromatographic solution, allowing the simultaneous analysis of a larger panel of metabolites, from very small and polar compounds, like trimethylamine, to quite lipophilic molecules, such as corticosterone. The proposed LC-HRMS protocol is an excellent alternative to hydrophilic interaction liquid chromatography and ion-pairing RP chromatography, thus providing another friendly analytical tool for metabolomics. Full article
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12 pages, 1566 KiB  
Article
Stabilization of Municipal Solid Waste Fly Ash, Obtained by Co-Combustion with Sewage Sludge, Mixed with Bottom Ash Derived by the Same Plant
by Ahmad Assi, Fabjola Bilo, Alessandra Zanoletti, Laura Borgese, Laura Eleonora Depero, Mario Nenci and Elza Bontempi
Appl. Sci. 2020, 10(17), 6075; https://doi.org/10.3390/app10176075 - 2 Sep 2020
Cited by 9 | Viewed by 2187
Abstract
This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue [...] Read more.
This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue gas desulfurization residues and coal fly ash. Leaching tests were performed on stabilized samples, aged in a laboratory at different times. The results reveal the reduction of the concentrations of heavy metals, particularly Zn and Pb about two orders of magnitude lower with respect to fly ash. The immobilization of heavy metals on the solid material mainly depends on three factors—the amount of used ash, the concentrations of Zn and Pb in as-received fly ash and the pH of the solution of the final materials. The inert powder, obtained after the stabilization, is a new eco-material, that is promising to be used as filler in new sustainable composite materials. Full article
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13 pages, 567 KiB  
Article
Determination of Non-Steroidal Anti-Inflammatory Drugs in Animal Urine Samples by Ultrasound Vortex-Assisted Dispersive Liquid–Liquid Microextraction and Gas Chromatography Coupled to Ion Trap-Mass Spectrometry
by Pasquale Avino, Ivan Notardonato, Sergio Passarella and Mario Vincenzo Russo
Appl. Sci. 2020, 10(16), 5441; https://doi.org/10.3390/app10165441 - 6 Aug 2020
Cited by 14 | Viewed by 2487
Abstract
A low solvent consumption method for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) in animal urine samples is studied. The NSAIDs were extracted with CH2Cl2 by the ultrasound vortex assisted dispersive liquid–liquid microextraction (USVA-DLLME) method from urine samples, previously treated [...] Read more.
A low solvent consumption method for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) in animal urine samples is studied. The NSAIDs were extracted with CH2Cl2 by the ultrasound vortex assisted dispersive liquid–liquid microextraction (USVA-DLLME) method from urine samples, previously treated with β-glucuronidase/acrylsulfatase. After centrifugation, the bottom phase of the chlorinated solvent was separated from the liquid matrix, dried with Na2SO4, and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) + trimethylchlorosilane (TMCS) (99 + 1). After cooling at room temperature, the solution was concentrated under nitrogen flow, and 1 µL of solution was analyzed in gas chromatography/ion trap-mass spectrometry (GC-IT-MS). The enrichment factor was about 300–450 times and recoveries ranged from 94.1 to 101.2% with a relative standard deviation (RSD) of ≤4.1%. The USVA-DLLME process efficiency was not influenced by the characteristics of the real urine matrix; therefore, the analytical method characteristics were evaluated in the range 1–100 ng mL−1 (R2 ≥ 0.9950). The limits of detection (LODs) and limits of quantification (LOQs) were between 0.1 and 0.2 ng mL−1 with RSD ≤4.5% and between 4.1 and 4.7 ng mL−1 with RSD ≤3.5%, respectively, whereas inter- and intra-day precision was 3.8% and 4.5%, respectively. The proposed analytical method is reproducible, sensitive, and simple. Full article
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15 pages, 2857 KiB  
Article
Microalgal Growth in Paper Industry Effluent: Coupling Biomass Production with Nutrients Removal
by Bruna Porto, Ana L. Gonçalves, Ana F. Esteves, Selene M. A. Guelli Ulson de Souza, Antônio A. Ulson de Souza, Vítor J. P. Vilar and José C. M. Pires
Appl. Sci. 2020, 10(9), 3009; https://doi.org/10.3390/app10093009 - 26 Apr 2020
Cited by 11 | Viewed by 3342
Abstract
Paper and pulp industries produce effluents with high phosphorus concentrations, which need to be treated before their discharge in watercourses. The use of microalgae for this purpose has attracted the attention of researchers because: (i) microalgae can assimilate phosphorus (one of the main [...] Read more.
Paper and pulp industries produce effluents with high phosphorus concentrations, which need to be treated before their discharge in watercourses. The use of microalgae for this purpose has attracted the attention of researchers because: (i) microalgae can assimilate phosphorus (one of the main nutrients for their growth); and (ii) growing on effluents can significantly reduce the costs and environmental impact of microalgal biomass production. This study evaluated the growth and ability of Chlorella vulgaris to remove the phosphorus from a secondary-treated effluent of a Portuguese paper company. Batch experiments were performed for 11 days using different dilutions of the effluent to evaluate its inhibitory effect on microalgae. Results showed that the non-diluted effluent inhibited microalgal growth, indicating that this bioremediation process is possible after a previous dilution of the effluent. Regarding phosphorus removal, promising results were achieved, especially in the experiments conducted with the most diluted effluent: removal efficiencies obtained in these conditions were (54 ± 1)%. Another interesting finding of this study was microalgal growth in flakes’ form (mainly due to the compounds present in the effluent and to the pH values achieved), which can be an important economic advantage for biomass recovery after the remediation step. Full article
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14 pages, 1945 KiB  
Article
Mucin-Grafted Polyethylene Glycol Microparticles Enable Oral Insulin Delivery for Improving Diabetic Treatment
by Momoh A. Mumuni, Ugwu E. Calister, Nafiu Aminu, Kenechukwu C. Franklin, Adedokun Musiliu Oluseun, Mohammed Usman, Barikisu Abdulmumuni, Oyeniyi Y. James, Kenneth C. Ofokansi, Attama A. Anthony, Emmanuel C. Ibezim and David Díaz Díaz
Appl. Sci. 2020, 10(8), 2649; https://doi.org/10.3390/app10082649 - 11 Apr 2020
Cited by 16 | Viewed by 2775
Abstract
In this study, different ratios of mucin-grafted polyethylene-glycol-based microparticles were prepared and evaluated both in vitro and in vivo as carriers for the oral delivery of insulin. Characterization measurements showed that the insulin-loaded microparticles display irregular porosity and shape. The encapsulation efficiency and [...] Read more.
In this study, different ratios of mucin-grafted polyethylene-glycol-based microparticles were prepared and evaluated both in vitro and in vivo as carriers for the oral delivery of insulin. Characterization measurements showed that the insulin-loaded microparticles display irregular porosity and shape. The encapsulation efficiency and loading capacity of insulin were >82% and 18%, respectively. The release of insulin varied between 68% and 92% depending on the microparticle formulation. In particular, orally administered insulin-loaded microparticles resulted in a significant fall of blood glucose levels, as compared to insulin solution. Subcutaneous administration showed a faster, albeit not sustained, glucose fall within a short time as compared to the polymeric microparticle-based formulations. These results indicate the possible oral delivery of insulin using this combination of polymers. Full article
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15 pages, 3722 KiB  
Article
Electrical Monitoring as a Novel Route to Understanding the Aging Mechanisms of Carbon Nanotube-Doped Adhesive Film Joints
by Xoan F. Sánchez-Romate, Alberto Jiménez-Suárez, María Sánchez, Silvia G. Prolongo, Alfredo Güemes and Alejandro Ureña
Appl. Sci. 2020, 10(7), 2566; https://doi.org/10.3390/app10072566 - 8 Apr 2020
Cited by 2 | Viewed by 1815
Abstract
Carbon fiber-reinforced plastic bonded joints with novel carbon nanotube (CNT) adhesive films were manufactured and tested under different aging conditions by varying the surfactant content added to enhance CNT dispersion. Single lap shear (SLS) tests were conducted in their initial state and after [...] Read more.
Carbon fiber-reinforced plastic bonded joints with novel carbon nanotube (CNT) adhesive films were manufactured and tested under different aging conditions by varying the surfactant content added to enhance CNT dispersion. Single lap shear (SLS) tests were conducted in their initial state and after 1 and 2 months immersed in distilled water at 60 °C. In addition, their electrical response was measured in terms of the electrical resistance change through thickness. The lap shear strength showed an initial decrease due to plasticization of weak hydrogen bonds, and then a partial recovery due to secondary crosslinking. This plasticization effect was confirmed by differential scanning calorimetry analysis with a decrease in the glass transition temperature. The electrical response varied with aging conditions, showing a higher plasticity region in the 1-month SLS joints, and a sharper increase in the case of the non-aged and 2-month-aged samples; these changes were more prevalent with increasing surfactant content. By adjusting the measured electrical data to simple theoretical calculations, it was possible to establish the first estimation of damage accumulation, which was higher in the case of non-aged and 2-month-aged samples, due to the presence of more prevalent brittle mechanisms for the CNT-doped joints. Full article
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Review

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24 pages, 4684 KiB  
Review
Arsenic Contamination of Groundwater and Its Implications for Drinking Water Quality and Human Health in Under-Developed Countries and Remote Communities—A Review
by Samuel B. Adeloju, Shahnoor Khan and Antonio F. Patti
Appl. Sci. 2021, 11(4), 1926; https://doi.org/10.3390/app11041926 - 22 Feb 2021
Cited by 65 | Viewed by 9185
Abstract
Arsenic is present naturally in many geological formations around the world and has been found to be a major source of contamination of groundwater in some countries. This form of contamination represents a serious threat to health, economic and social well-being, particularly in [...] Read more.
Arsenic is present naturally in many geological formations around the world and has been found to be a major source of contamination of groundwater in some countries. This form of contamination represents a serious threat to health, economic and social well-being, particularly in under-developed countries and remote communities. The chemistry of arsenic and the factors that influence the form(s) in which it may be present and its fate when introduced into the environment is discussed briefly in this review. A global overview of arsenic contamination of groundwater around the world is then discussed. As a case study, the identified and established causes of groundwater contamination by arsenic in Bangladesh is highlighted and a perspective is provided on the consequential health, agricultural, social and economic impacts. In addition, the relevant removal strategies that have been developed and can generally be used to remediate arsenic contamination are discussed. Also, the possible influence of groundwater inorganic compositions, particularly iron and phosphate, on the effectiveness of arsenic removal is discussed. Furthermore, some specific examples of the filter systems developed successfully for domestic arsenic removal from groundwater to provide required potable water for human consumption are discussed. Lastly, important considerations for further improving the performance and effectiveness of these filter systems for domestic use are outlined. Full article
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