Publications by authors named "Tawfik A Saleh"

63 Publications

Photochemically Produced Superhydrophobic Silane@polystyrene-Coated Polypropylene Fibrous Network for Oil/Water Separation.

Chem Asian J 2021 Feb 22;16(4):329-341. Epub 2021 Jan 22.

Chemistry Department, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

Cost-effective separation of oil and immiscible organic contaminants from water has become an urgent challenge to protect aquatic and human life from devastating effects. Therefore, it has become imperative to develop super-selective materials for efficiently separating oil from water. In this work, a superhydrophobic surface has been formed that consists of a silane@polystyrene-coated polypropylene fibrous network (silane@PS-PPF) for efficient separation of accidentally spilled oil from water. The superhydrophobic PPFs were designed by a simple, cost-effective two-step process that includes photochemically controlled polymerization of styrene and subsequent dip coating in octadecyltrichlorosilane solution. The hydrophobic surface (CA=129°±4°) of the PS coated PPF after treating with silane was turned into a superhydrophobic body (CA=161°±2°). The achieved silane@PS-PPF fibrous network selectively allowed the fast permeation of the oils and non-polar organic liquids by altogether rejecting water during operation. The separation efficiency for various oils from the contaminated water was 96 to 99%, with a high flux in the range of 7606±312 L m h to 9870±151 L m h . Apart from being used as a filter, the silane@PS-PPF was also used as an oil absorber and has shown an absorption capacity in the range of 1185 to 1535% for various oils. We anticipate that the developed silane@PS-PPF, due to its facile synthetic route, cost-effectiveness, and high performance, can be effectively used in oily wastewater treatment and clean-up of large oil spills from water.
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http://dx.doi.org/10.1002/asia.202001368DOI Listing
February 2021

Visible Light-Driven Photoelectrocatalytic Water Splitting Using Z-Scheme Ag-Decorated MoS/RGO/NiWO Heterostructure.

ACS Omega 2020 Dec 1;5(49):31644-31656. Epub 2020 Dec 1.

Center of Research Excellence in Renewable Energy Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.

Herein, we have successfully constructed a solid-state Z-scheme photosystem with enhanced light absorption capacity by combining the optoelectrical properties of AgNPs with those of the MoS/RGO/NiWO (Ag-MRGON) heterostructure. The Ag-MRGON Z-scheme system demonstrates improved photo-electrochemical (PEC) water-splitting performance in terms of applied bias photon-to-current conversion efficiency (ABPE), which is 0.52%, and 17.3- and 4.3-times better than those of pristine MoS and MoS/NiWO photoanodes, respectively. The application of AgNPs as an optical property enhancer and RGO as an electron mediator improved the photocurrent density of Ag-MRGON to 3.5 mA/cm and suppressed the charge recombination to attain the photostability of ∼2 h. Moreover, the photocurrent onset potential of the Ag-MRGON heterojunction ( 0.61 V) is cathodically shifted compared to those of NiWO (0.83 V), MoS (0.80 V), and MoS/NiWO heterojunction (0.73 V). The improved PEC water-splitting performance in terms of ABPE, photocurrent density, and onset potential is attributed to the facilitated charge transfer through the RGO mediator, the plasmonic effect of AgNPs, and the proper energy band alignments with the thermodynamic potentials of hydrogen and oxygen evolution.
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http://dx.doi.org/10.1021/acsomega.0c03985DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7745211PMC
December 2020

A review on multicomponent reactions catalysed by zero-dimensional/one-dimensional titanium dioxide (TiO) nanomaterials: Promising green methodologies in organic chemistry.

J Environ Manage 2021 Feb 7;279:111603. Epub 2020 Nov 7.

Department of Pharmaceutics, SETs' College of Pharmacy, Dharwad, 580 007, Karnataka, India. Electronic address:

Heterogeneous catalysis has currently become an emerging tool for the design and development of sustainable manufacturing processes in order to obtain advanced intermediates, fine chemicals, and bioactive molecules. This field has been considered efficient and eco-friendly, as it investigates the utilization of non-hazardous metals for atom-economical reactions. Nanomaterials have created a significant impact on scientific and engineering advancements due to their tunable properties with superior performance over their massive counterparts. Due to the increased demand for heterogeneous catalysts in industries and academia, different transition metal oxides have been made into substantial nanostructures. Among them, titanium dioxide (TiO) nanomaterials have received more attention on account of their chemical stability, low cost, dual acid-base properties, good oxidation rate and refractive index. Different modifications of TiO extend their applications as active catalysts or catalyst supports in diverse catalytic processes, such as photovoltaics, lithium batteries, pigments and others. One-dimensional (1-D) TiO nanostructures such as nanotubes, nanowires and nanorods have achieved greater importance owing to the unique properties of improved porosity, decreased inter-crystalline contacts, large surface-to-volume ratio, superior dispersibility, amplified accessibility of hydroxyl (-OH) groups and presence of good concentrations of Brønsted/Lewis acid sites. Since the discovery, 1-D TiO nanostructures have served good photocatalytic applications, but were less explored in organic transformations. While many articles and reviews have covered the applications of 0-D and 1-D TiO nanostructured materials (NSMs) in photoelectrochemical reactions and solar cells, there are other interesting applications of these as well. In contrast to the conventional multi-step processes that utilise the stepwise formation of individual bonds, one-pot conversions based on multicomponent reactions (MCRs) have acquired much significance in contemporary organic synthesis. This paper presents a critical review on history, classification, design and synthetic utility of titania-based nanostructures, which could be used as robust solid-acid catalysts and catalyst supports for MCRs. Further, to put ideas into perspective, the introduction and applications of MCRs for various organic transformations have been discussed.
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http://dx.doi.org/10.1016/j.jenvman.2020.111603DOI Listing
February 2021

Novel Porous Organic Polymer for the Concurrent and Selective Removal of Hydrogen Sulfide and Carbon Dioxide from Natural Gas Streams.

ACS Appl Mater Interfaces 2020 Oct 8;12(42):47984-47992. Epub 2020 Oct 8.

Department of Chemistry, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia.

Natural gas sweetening currently requires multistep, complex separation processes to remove the acid gas contaminants, carbon dioxide and hydrogen sulfide. In addition to being widely recognized as energy inefficient and cost-intensive, the effectiveness of this conventional process also suffers considerably because of limitations of the sorbent materials it employs. Herein, we report a new porous organic polymer, termed KFUPM-5, that is demonstrated to be effective in the concurrent separation of both hydrogen sulfide and carbon dioxide from a mixed gas stream at ambient conditions. To understand the ability of KFUPM-5 to selectively capture these gas molecules, we performed both pure-component thermodynamic and mixed gas kinetic adsorption studies and correlated these results with theoretical molecular simulations. Our results show that the underlying polar backbone of KFUPM-5 provides favorable adsorption sites for the selective capture of these gas molecules. The outcome of this work lends credence to the prospect that, for the first time, porous organic polymers can serve as sorbents for industrial natural gas sweetening processes.
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http://dx.doi.org/10.1021/acsami.0c14259DOI Listing
October 2020

Kinetic and thermodynamic studies of fenton oxidative decolorization of methylene blue.

Heliyon 2020 Aug 26;6(8):e04454. Epub 2020 Aug 26.

Chemistry Department, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

The need for light intensity has made dye degradation very costly for industry. In this work, Fenton reagent was used for the efficient degradation of an aqueous solution of dye without the need for a light source. The influences of the pH of the media, the initial concentrations of Fe, HO, and methylene blue (MB) dye; in addition to temperature on the oxidation of MB dye were studied. The optimum amounts of the Fenton reagent were 4mM of Fe and 70mM of HO at 20 mg/L of dye. The optimum ratio of 0.05 of Fe/HO was found to give the best result for the decolorization of dye. The Fenton process was effective at pH 3 with a maximum dye decolorization efficiency of 98.8% within 30 min of reaction, corresponding to a COD removal of 85%. The decolorization process was thermodynamically feasible, spontaneous, and endothermic. The activation energy (E) was 33.6 kJ/mol suggesting that the degradation reaction proceeded with a low energy barrier.
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http://dx.doi.org/10.1016/j.heliyon.2020.e04454DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7452397PMC
August 2020

Synthesis of a new thiophenol-thiophene polymer for the removal of mercury from wastewater and liquid hydrocarbons.

J Colloid Interface Sci 2021 Jan 25;582(Pt A):428-438. Epub 2020 Jul 25.

Department of Chemistry, King Fahd University of Petroleum and Minerals, 31261 Dhahran, Saudi Arabia. Electronic address:

This work reports the synthesis of a novel thiophenol-thiophene polymer (termed KFUPM-Hg) and its suitability as an adsorbent for mercury removal from wastewater and liquid hydrocarbons. KFUPM-Hg was synthesized through a Friedel-Crafts polycondensation reaction of thiophenol and thiophene in the presence of p-formaldehyde as a linker. The crosslinked polymer structure was characterized using solid-state C-nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR). Thermogravimetric analysis was performed to assess the polymer thermal stability, which indicated that the polymer is thermally stable to over 300 °C. A series of batch adsorption studies were used to investigate the effects of different parameters (pH, temperature, concentration, and time) on the mercury removal from aqueous solution as well as from a model liquid hydrocarbon media (decane/toluene mixture). The batch adsorption studies in aqueous media showed near quantitative removal of inorganic mercury (II) at 100 ppm using the thiophenol-thiophene polymer adsorbent. Furthermore, the thiophenol-thiophene polymer demonstrated excellent removal capabilities of methylmercury in a decane/toluene hydrocarbon mixture. Mercury adsorption onto KFUPM-Hg is an exothermic reversible physical process and follows pseudo-second order adsorption kinetics. Remarkably, these removal capabilities were achieved using polymers that directly incorporated thiophenol and thiophene groups during synthesis without the use of thiol-ene post-synthesis modifications.
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http://dx.doi.org/10.1016/j.jcis.2020.07.103DOI Listing
January 2021

Evaluation of the corrosion inhibition efficacy of Cola acuminata extract for low carbon steel in simulated acid pickling environment.

Environ Sci Pollut Res Int 2020 Sep 16;27(27):34270-34288. Epub 2020 Jun 16.

Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.

In this study, Kola nut extract (KE) was evaluated for inhibiting ability towards low carbon steel corrosion in 1 M HCl solution using weight loss and electrochemical techniques. The surface of the corroded carbon steel was examined by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Elemental composition of the corrosion products and/or adsorbed inhibitor film on the carbon steel surface was determined with the aid of an energy-dispersive X-ray spectroscopy (EDX). The ultraviolet-visible (UV-vis) experiments were also performed to get information about the interaction of KE with the carbon steel surface. It was found that KE exhibited good corrosion protection property. From weight loss technique, corrosion rate was reduced from 0.387 to 0.054 mm/year by 700 ppm of KE at room temperature after 24 h immersion and this corresponded to inhibition efficiency (IE) of 86%. The IE however depreciated with rise in temperature. FTIR results reveal that KE interacted with the carbon steel surface through the O and N heteroatoms of its phytoconstituents. FTIR spectroscopy, UV-vis, SEM, AFM, and EDX data provided proof of KE adsorption on the steel surface as reason for the corrosion inhibition.
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http://dx.doi.org/10.1007/s11356-020-09636-wDOI Listing
September 2020

Eu , Sm Deep-Red Phosphors as Novel Materials for White Light-Emitting Diodes and Simultaneous Performance Enhancement of Organic-Inorganic Perovskite Solar Cells.

Small 2020 Jun 27;16(25):e2001551. Epub 2020 May 27.

Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

The luminous efficiency of inorganic white light-emitting diodes, to be used by the next generation as light initiators, is continuously progressing and is an emerging interest for researchers. However, low color-rendering index (Ra), high correlated color temperature (CCT), and poor stability limit its wider application. Herein, it is reported that Sm - and Eu -doped calcium scandate (CaSc O (CSO)) are an emerging deep-red-emitting material with promising light absorption, enhanced emission properties, and excellent thermal stability that make it a promising candidate with potential applications in emission display, solid-state white lighting, and the device performance of perovskite solar cells (PSCs). The average crystal structures of Sm -doped CSO are studied by synchrotron X-ray data that correspond to an extremely rigid host structure. Samarium ion is incorporated as a sensitizer that enhances the emission intensity up to 30%, with a high color purity of 88.9% with a 6% increment. The impacts of hosting the sensitizer are studied by quantifying the lifetime curves. The CaSc O :0.15Eu ,0.03Sm phosphor offers significant resistance to thermal quenching. The incorporation of lanthanide ion-doped phosphors CSOE into PSCs is investigated along with their potential applications. The CSOE-coated PSCs devices exhibit a high current density and a high power conversion efficiency (15.96%) when compared to the uncoated control devices.
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http://dx.doi.org/10.1002/smll.202001551DOI Listing
June 2020

Partially aminated acrylic acid grafted activated carbon as inexpensive shale hydration inhibitor.

Carbohydr Res 2020 May 5;491:107960. Epub 2020 Mar 5.

Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia. Electronic address:

In this work, we report the preparation of a novel partially aminated and inexpensive water-soluble acrylic acid grafted activated carbon represented as C-g-AA-NH for efficient inhibition of shale hydration. The as-prepared C-AA-NH was subjected to Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR), and thermal gravimetric analysis (TGA). This was followed by an evaluation of the capability of the material to inhibit shale through various tests including anti-swelling, shale recovery, and immersion tests. Our results indicated that 2% of C-g-AA-NH drastically reduced water invasion into shale by combining plugging property of the core-centered carbon nanoparticles with the inhibition ability of the partially aminated acrylic acid component by adsorption on the clay surface through hydrogen bonding. In this manner, the plugging of the pore throat of the interlayer spacing of the shale formation could easily be achieved. This approach could significantly control fluid loss, reduce permeability and filtrate volume of drilling mud by forming a thin film on the formation surface due to the nano-nature of the carbon component of the polymer.
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http://dx.doi.org/10.1016/j.carres.2020.107960DOI Listing
May 2020

Evaluation of carbonized waste tire for development of novel shape stabilized composite phase change material for thermal energy storage.

Waste Manag 2020 Feb 7;103:352-360. Epub 2020 Jan 7.

School of Energy Management, Shri Mata Vaishno Devi University, Katra 182320, J&K, India; Center of Research Excellence in Renewable Energy and Power Systems, King Abdulaziz University, Jeddah 80200, Saudi Arabia.

This work is focused on the preparation of an activated charcoal by carbonization of waste tire rubbers (WTRs) and its evaluation for shape-stabilization of dodecyl alcohol (DDA) as an organic phase change material (PCM) used for thermal energy storage (TES). In the composite, DDA had TES function as carbonized waste tire (CWT) acted as supporting and thermal conductive frameworks. CWT prevented leakage of melted DDA during phase change due to its good adsorption ability until the weight ratio of DDA reached 78%. The shape-stabilized composite PCM was characterized by FT-IR, XRD, SEM, DSC and TGA techniques. The DSC results revealed that the composite PCM had very appropriate melting point of 21.68 ± 0.12 °C and considerable high latent heat capacity of 181.6 ± 1.2 J/g for thermoregulation of buildings. Compared to DDA, thermal degradation temperature of the composite PCM was extended as about 50 °C. The 500-cycled composite PCM had still showed reliable TES properties. Additionally, thermal conductivity (0.431 ± 0.010 W/m·K) of the composite PCM was measured as about 2.3 times higher than that of DDA. The heating and cooling periods of the composite PCM were reduced by 17.2 and 20.0%, respectively compared to that of DDA due to its enhanced thermal conductivity. All results suggested that the produced CWT as low-cost and environmental friendly supporting material can be evaluated for absorbing PCMs used for passive solar TES utilization in buildings.
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http://dx.doi.org/10.1016/j.wasman.2019.12.051DOI Listing
February 2020

Bis(2-aminoethyl)amine-modified graphene oxide nanoemulsion for carbon steel protection in 15% HCl: Effect of temperature and synergism with iodide ions.

J Colloid Interface Sci 2020 Mar 28;564:124-133. Epub 2019 Dec 28.

Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.

Hypothesis: There is a scarcity of available literature studies on the inhibition of aqueous corrosion using graphene and graphene oxide (GO) due to their poor aqueous solubility. The abundance of oxygen-containing functional groups on the surface of GO offers promising aspects for its chemical modification. Accordingly, we herein report the application of bis(2-aminoethyl)amine-modified graphene oxide (B2AA-GO) as a corrosion inhibitor for carbon steel in industrial oil-well acidizing conditions.

Experiments: B2AA was used to modify the graphene oxide (GO) chemically and characterized using FTIR, SEM, and TEM. The corrosion evaluations were undertaken in 15% HCl using weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization techniques supported by a thorough surface analysis using water contact angle measurements, FTIR, and atomic force microscopy.

Findings: It observed that the B2AA-GO acted by adsorption on the metal surface and exhibited a mixed type of nature with cathodic prevalence. The results showed that the chemically modified GO exhibits excellent inhibition behavior showing 90.27% corrosion inhibition efficiency up to 65 °C. Furthermore, iodide ions were introduced to improve the inhibition efficiency of the GO via synergistic action and inhibition efficiency of 96.77% was obtained at 65 °C. The obtained results show that the chemically modified GO is a promising corrosion inhibitor in the acidizing environment.
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http://dx.doi.org/10.1016/j.jcis.2019.12.125DOI Listing
March 2020

A study on the spectral, microstructural, and magnetic properties of Eu-Nd double-substituted BaSrFeO hexaferrites synthesized by an ultrasonic-assisted approach.

Ultrason Sonochem 2020 Apr 4;62:104847. Epub 2019 Nov 4.

Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, 31441 Dammam, Saudi Arabia.

In this study, an examination on the spectral, microstructural, and magnetic characteristics of Eu-Nd double-substituted BaSrFeO hexaferrites (BaSrNdEuFeO (x = 0.00-0.05) HFs) fabricated by an ultrasonic-assisted approach has been presented. An UZ SONOPULS HD 2070 ultrasonic homogenizer with frequency of 20 kHz and power of 70 W was used. The chemical bonding, structure and the morphology of the products were evaluated by Fourier-Transform Infrared (FT-IR) Spectroscopy, XRD (X-ray diffraction), scanning and transmission electron microscopy and techniques. The textural properties of the prepared nanomaterials were examined by using the Brunauer-Emmett-Teller (BET) method. The magnetic properties were studied using a vibrating sample magnetometer (VSM) at room temperature (RT) and low temperature 10 K. The magnitudes of various magnetic parameters including M (saturation magnetization), M (remanence) and H (coercivity) were estimated and evaluated. The M-H loops revealed the hard ferrimagnetic nature for all products at both temperatures. The M and M values showed a decreasing tendency with increasing degree of Eu and Nd substitutions whereas H values displayed an increasing trend. At RT, M, M and H values lie in the ranges of 63.0-68.8 emu·g, 24.6-39.2 emu·g and 2252.4-2782.1 Oe, respectively. At 10 K, the values of M, M and H lie between 87.5-97.1 emu·g, 33.5-40.1 emu·g and 2060.6-2417.2 Oe, respectively. The observed magnetic properties make the prepared products promising candidates to be applied in the recording media.
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http://dx.doi.org/10.1016/j.ultsonch.2019.104847DOI Listing
April 2020

Recent Advances in Functionalized Carbon Dots toward the Design of Efficient Materials for Sensing and Catalysis Applications.

Small 2020 01 26;16(1):e1905767. Epub 2019 Nov 26.

Chemistry Department, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

Since the past decade, enormous research efforts have been devoted to the detection/degradation and quantification of environmental toxic pollutants and biologically important molecules due to their ubiquitous necessity in the fields of environmental protection and human health. These fields of sensor and catalysis are advanced to a new era after emerging of nanomaterials, especially, carbon nanomaterials including graphene, carbon nanotube, carbon dots (C-dots), etc. Among them, the C-dots in the carbon family are rapidly boosted in the aspect of synthesis and application due to their superior properties of chemical and photostability, highly fluorescent with tunable, non/low-toxicity, and biocompatibility. The C-dot-based functional materials have shown great potential in sensor and catalysis fields for the detection/degradation of environmental pollutants. The major advantage of C-dots is that they can be easily prepared from numerous biomass/waste materials which are inexpensive and environment-friendly and are suitable for a developing trend of sustainable materials. This review is devoted to the recent development (since 2017) in the synthesis of biomass- and chemical-derived C-dots as well as diverse functionalization of C-dots. Their capability as a sensor and catalyst and respective mechanism are summarized. The future perspectives of C-dots are also discussed.
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http://dx.doi.org/10.1002/smll.201905767DOI Listing
January 2020

Removal of toxic metals from wastewater in constructed wetlands as a green technology; catalyst role of substrates and chelators.

Ecotoxicol Environ Saf 2020 Feb 21;189:109924. Epub 2019 Nov 21.

King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia. Electronic address:

In recent years knowledge in regard to phytoremediation for removal of metals from wastewater has been extensively developed. Despite advance treatment methods; different plants were widely used for wastewater treatment that may affect the efficiency of plants by stressing their natural ability. Therefore, this paper reviews the catalytic role of constructed wetlands, spiking of chelators and substrates to enhance phytoremediation for removal of metals. Catalytic combination of substrates, chelators with plants helped to remove different metals from wastewater simultaneously without compromising the plant's health. Moreover, this paper summarizes the interaction mechanism of plants with the chelators and substrates within constructed wetlands. In addition, this paper also discusses the potential research needs for this field.
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http://dx.doi.org/10.1016/j.ecoenv.2019.109924DOI Listing
February 2020

Highly efficient solar light-driven photocatalytic hydrogen production over Cu/FCNTs-titania quantum dots-based heterostructures.

J Environ Manage 2020 Jan 5;254:109747. Epub 2019 Nov 5.

Pharmaceutical Engineering, Soniya College of Pharmacy, Dharwad, 580 002, India. Electronic address:

The need for clean and eco-friendly energy sources has increased enormously over the years due to adverse impacts caused by the detrimental fossil fuel energy sources on the environment. This work reports the safest and most efficient route for hydrogen generation using solar light receptive functionalized carbon nanotubes-titania quantum dots (FCNT-TQDs) as photocatalysts under the influence of solar light irradiation. Predominantly, dual capability of CNT as co-catalyst and photo-sensitizer reduced the recombination rate of charge carriers, and facilitated the efficient light harvesting. The bulk production of hydrogen via water harvesting is considered, wherein photocatalyst synthesized was tuned by the optimum addition of copper to achieve higher production rate of hydrogen up to 54.4 mmol hg, nearly 25-folds higher than that of pristine TiO quantum dots. Addition of copper has a crucial role in improving the rate of hydrogen generation. The ternary composite exhibited 5.4-times higher hydrogen production compared to FCNT-TQDs composite.
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http://dx.doi.org/10.1016/j.jenvman.2019.109747DOI Listing
January 2020

Carbon nanotubes grafted with poly(trimesoyl, m-phenylenediamine) for enhanced removal of phenol.

J Environ Manage 2019 Dec 9;252:109660. Epub 2019 Oct 9.

Tokat Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250, Tokat, Turkey; King Fahd University of Petroleum and Minerals, Research Institute, Center for Environment and Water, Dhahran, 31261, Saudi Arabia.

This work focused on the facile synthesis of carbon nanotubes grafted with a polymer of trimesoyl chloride and m-phenylenediamine (CNTs-MDP-TMC) as novel and effective adsorbent and investigation of its ability in the phenol uptake from aqueous media. The chemical and morphological characterization of the synthesized adsorbent was carried out by FT-IR, SEM, EDX, and mapping techniques. The influence of the operational parameters on the adsorption performance was inspected and optimized batch adsorption conditions by factorial design analysis. The non-linear Langmuir model was better represented the isotherm of phenol adsorption compared to the Freundlich isotherm. The CNTs-MDP-TMC had a maximum adsorption capacity as much as 261.6 mg/g. The kinetic examinations revealed that the pseudo-second-order (PSO) kinetic model depicted higher relationship with phenol adsorption than the pseudo-first-order (PFO) model. The thermodynamics findings confirmed that the phenol adsorption by the CNTs-MDP-TMC is taken place exothermically and more spontaneously with lessening temperature. The prepared adsorbent had a great adsorption/desorption performance, especially during the first four cycles. It can be drawn a conclusion form all findings that the synthesized CNTs-MDP-TMC has great prospective as a novel and influential adsorbent for phenol polluted-wastewaters.
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http://dx.doi.org/10.1016/j.jenvman.2019.109660DOI Listing
December 2019

Superhydrophobic Polypropylene Functionalized with Nanoparticles for Efficient Fast Static and Dynamic Separation of Spilled Oil from Water.

Glob Chall 2019 Aug 26;3(8):1800115. Epub 2019 Apr 26.

Chemistry Department King Fahd University of Petroleum & Minerals Dhahran 31261 Saudi Arabia.

Frequent oil spills not only threaten the ecosystem, but they are also a waste of a valuable source of energy. There is an urgent need to develop materials that can readily remove spilled oil from water bodies and also have the capacity to collect it for energy applications. Herein, a superhydrophobic fiber of functionalized polypropylene is engineered with the help of palmitic acid interaction with incorporated copper oxide nanoparticles. The successful development of functionalized polypropylene is confirmed by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy. The scanning electron microscopy images reveal that the surface roughness of the polypropylene is enhanced after functionalization. The optimized functionalized polypropylene displays an ultrahydrophobic surface with a water contact angle of 162.42°. The functionalized polyprolyene displays good absorption capacity. It has the capacity to take 30 to 40 times its own weight in oils and nonpolar organic solvents, which makes it useful for small spills. With a flux of 11 204 Lm h, functionalized polypropylene is as an ideal material for the dynamic separation of oil spills from water. It also has excellent selectivity towards oil, water rejection, and oil absorption capacity.
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http://dx.doi.org/10.1002/gch2.201800115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686158PMC
August 2019

Natural-Light-Initiated 3D Macro Zigzag Architecture of Graphene-Reinforced Polystyrene for Gravity-Driven Oil and Water Separation.

Glob Chall 2018 Nov 2;2(11):1800040. Epub 2018 Sep 2.

Chemistry Department King Fahd University of Petroleum & Minerals Dhahran 31261 Saudi Arabia.

Superhydrophobic 3D robust materials are introduced for the separation of hexane and water. For the first time, novel 3D zigzag polystyrene on graphene-incorporated polyurethane (3D zz-PS/GR/PU) is prepared using exclusively natural sunlight without any chemical initiator. The zigzag polystyrene growth is accomplished by polymerizing the styrene vapors. The natural sunlight provides a compact 3D zz-PS/GR/PU material with superoleophilic and hydrophobic channels that allow for the rapid passage of oil, whereas water is entirely prevented from passing. The 3D zz-PS/GR/PU compact channels are transformed into the compressible material by treating them with toluene without affecting the hydrophobicity of the material. The 3D zz-PS/GR/PU displays a high-water contact angle of approximately 150°. The developed materials are characterized by FTIR, SEM, and BET. The graphene incorporation makes surface area of the 3D zz-PS/GR/PU substantially large compared with PU. It is improved from 15 to 67 m g. The pore size of the adsorption and desorption in the 3D zz-PS/GR/PU is also reduced from 354 and 352 Å to 34 and 33 Å. The 3D zz-PS/GR/PU satisfies the requirement of high-demanding superhydrophobic materials, like a low-cost fabrication process, reusability, and tunability. This strategy can trigger large-scale production with a controlled morphology.
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http://dx.doi.org/10.1002/gch2.201800040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6607307PMC
November 2018

Band gap tuning and surface modification of carbon dots for sustainable environmental remediation and photocatalytic hydrogen production - A review.

J Environ Manage 2019 Nov 10;250:109486. Epub 2019 Sep 10.

Pharmaceutical Engineering, Sonia College of Pharmacy, Dharwad, 580 002, Karnataka, India. Electronic address:

Energy and water are the two major issues facing the modern mankind. Providing freshwater requires energy and producing energy uses water. In the present-day scenario, both these routes face growing problems and limitations. Energy crisis has risen due to the depletion of fossil fuels that cause pollution to water bodies making the water unusable for human consumption. In this regard, semiconductor nanocrystals with luminescent properties or carbon quantum dots (CQDs) are the newly developed nanomaterials whose distinctive photo-physical characteristics are focusing to a new generation of robust materials and sensors for sustainable development. In this review, advances in surface and band gap modification of CQDs to improve the activity of nanomaterials will be discussed with special reference to some specific CQDs exhibiting special optical properties for water treatment/splitting applications. Recent advances on CQDs nanocomposites including their applications in photodegradation of organic pollutants, sensing of heavy metal ions in water and water splitting are discussed critically to narrate the future prospects in this field. Challenges and limitations for further improvement are covered to provide smart choices for creating sustainability of benign environment and economic benefits.
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http://dx.doi.org/10.1016/j.jenvman.2019.109486DOI Listing
November 2019

Pseudobactins bounded iron nanoparticles for control of an antibiotic-resistant Pseudomonas aeruginosa ryn32.

Biotechnol Prog 2020 01 22;36(1):e2907. Epub 2019 Oct 22.

Research Sector, Albassam High Schools, Dammam City, Saudi Arabia.

Among 50 strains of Pseudomonas aeruginosa tested for the resistance to antibiotics, strain ryn32 was selected for this study based on its resistance level. It showed complete resistance toward aztreonam and almost complete resistance (96%) against kanamycin. Iron nanoparticles (FeNPs) were then prepared and found with diameters 30-50 nm. The threshold level of FeNPs for pyoverdines (PVDs) production by P. aeruginosa ryn32 was found at 25 μM concentration. PVDs production was optimal with pH 7.5, 35°C, succinate as carbon source, ammonium sulfate as nitrogen source at 60 hr fermentation time. Interestingly, when used the PVDs as conjugates with FeNPs they showed antibacterial action against the producing strain and some other gram-negative bacteria. This suggests that the conjugates enter the bacterial cell via the ferriPVDs uptake pathway, which triggers the accumulation of FeNPs inside the cell, which is crucial on bacterial viability. Growth stimulation with the same concentrations of FeNPs and PVDs in separate treatments supported this view.
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http://dx.doi.org/10.1002/btpr.2907DOI Listing
January 2020

Antagonist effects of strains of Bacillus spp. against Rhizoctonia solani for their protection against several plant diseases: Alternatives to chemical pesticides.

C R Biol 2019 Jun - Aug;342(5-6):124-135. Epub 2019 Aug 9.

Statistical Genomics Lab, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.

Rhizoctonia solan Kühn (teleomorph: Thanatephorus cucumeris (Frank) Donk (R. solani) is a soil-borne phytopathogenic species complex as well as a necrotic fungus that causes significant crop yield losses worldwide. Agronomic practices (crop rotation), resistant cultivars, and chemical pesticides are widely used to control R. solani. However, these practices are insufficient to control the pest. Moreover, the application of chemical pesticides is harmful to both the environment and human health. Therefore, the use of biocontrol agents (BCAs) and that of plant-growth promoting bacteria (PGPB) are considered to be potentially sustainable, cost-effective, efficient, and eco-friendly ways to control R. solani. Several microorganisms have been used as biocontrol agents (BCAs) to manage R. solani. Among these, biocontrol agents (BCAs) Bacillus spp. are used to promote plant growth. Furthermore, due to its broad range of antibiotic-producing abilities, Bacillus spp. is widely used against R. solani. In this review, current and previous studies about the ability of Bacillus spp. to control diseases caused by R. solani are reported. It also focuses on the plant-growth promotion attributes of Bacillus spp. in response to the deleterious effects of R. solani.
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http://dx.doi.org/10.1016/j.crvi.2019.05.002DOI Listing
December 2019

Hemodialysis performance and anticoagulant activities of PVP-k25 and carboxylic-multiwall nanotube composite blended Polyethersulfone membrane.

Mater Sci Eng C Mater Biol Appl 2019 Oct 18;103:109769. Epub 2019 May 18.

Institute of Bioproduct Development, Department of Bioprocess and Polymer Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia. Electronic address:

Non-covalent electrostatic interaction between amide nitrogen and carbonyl carbon of shorter chain length of polyvinylpyrrolidone (PVP-k25) was developed with in-house carboxylic oxidized multiwall carbon nanotubes (O-MWCNT) and then blended with Polyethersulfone (PES) polymer. FTIR analysis was utilized to confirm bonding nature of nano-composites (NCs) of O-MWCNT/PVP-k25 and casting membranes. Non-solvent induces phase separation process developed regular finger-like channels in composite membranes whereas pristine PES exhibited spongy entities as studied by cross sectional analysis report of FESEM. Further, FESEM instrument was also utilized to observe the dispersion of O-MWCNT/PVP based nanocomposite (NCs) with PES and membranes leaching phenomena analysis. Contact angle experiments described 24% improvement of hydrophilic behaviour, leaching ratio of additives was reduced to 1.89%, whereas water flux enhanced up to 6 times. Bovine serum albumin (BSA) and lysozyme based antifouling analysis shown up to 25% improvement, whereas 84% of water flux was regained after protein fouling than pristine PES. Anticoagulant activity was reported by estimating prothrombin, thrombin, plasma re-calcification times and production of fibrinogen cluster with platelets-adhesions photographs and hemolysis experiments. Composite membranes exhibited 3.4 and 3 times better dialysis clearance ratios of urea and creatinine solutes as compared to the raw PES membrane.
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http://dx.doi.org/10.1016/j.msec.2019.109769DOI Listing
October 2019

Development of a predictive model for estimating the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids using support vector regression.

Heliyon 2019 Jun 26;5(6):e01882. Epub 2019 Jun 26.

Department of Chemistry, King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, 31261, Saudi Arabia.

The specific heat capacity of nanofluids is a fundamental thermophysical property that measures the heat storage capacity of the nanofluids. is usually determined through experimental measurement. As it is known, experimental procedures are characterised with some complexities, which include, the challenge of preparing stable nanofluids and relatively long periods to conduct experiments. So far, two correlations have been developed to estimate the The accuracies of these models are still subject to further improvement for many nanofluid compositions. This study presents a four-input support vector regression (SVR) model hybridized with a Bayesian algorithm to predict the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. The bayesian algorithm was used to obtain the optimum SVR hyperparameters. 189 experimental data collected from published literature was used for the model development. The proposed model exhibits low average absolute relative deviation (AARD) and a high correlation coefficient (r) of 0.40 and 99.53 %, respectively. In addition, we analysed the accuracies of the existing analytical models on the considered nanofluid compositions. The model based on the thermal equilibrium between the nanoparticles and base fluid (model II) show good agreement with experimental results while the model based on simple mixing rule (model I) overestimated the specific heat capacity of the nanofluids. To further validate the superiority of the proposed technique over the existing analytical models, we compared various statistical errors for the three models. The AARD for the BSVR, model II, and model I are 0.40, 0.82 and 4.97, respectively. This clearly shows that the model developed has much better prediction accuracy than existing models in predicting the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. We believe the presented model will be important in the design of nanofluid-based applications due to its improved accuracy.
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http://dx.doi.org/10.1016/j.heliyon.2019.e01882DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6600000PMC
June 2019

Nonenzymatic amperometric dopamine sensor based on a carbon ceramic electrode of type SiO/C modified with CoO nanoparticles.

Mikrochim Acta 2019 06 25;186(7):471. Epub 2019 Jun 25.

Interdisciplinary Research Centre in Biomedical Materials (IRCBM), COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore, 54000, Pakistan.

An amperometric nonenzymatic dopamine sensor has been developed. Cobalt oxide (CoO) nanoparticles were uniformly dispersed inside mesoporous SiO/C. A sol-gel process was used for the preparation of this mesoporous composite material (SiO/C). This mesoporous composite has a pore size of around 13-14 nm, a large surface area (S 421 m·g) and large pore volume (0.98 cm·g) as determined by the BET technique. The material compactness was confirmed by SEM images which showing that there is no phase segregation at the magnification applied. The chemical homogeneity of the materials was confirmed by EDX mapping. The SiO/C/CoO nanomaterial was pressed in desk format to fabricate a working electrode for nonenzymatic amperometric sensing of dopamine at a pH value of 7.0 and at a typical working potential of 0.25 V vs SCE. The detection limit, linear response range and sensitivity are 0.018 μmol L, 10-240 μmol L, and 80 μA·μmol L cm, respectively. The response timé of the electrode is less than 1 s in the presence of 60 μmol L of dopamine. The sensor showed chemically stability, high sensitivity and is not interfered by other electroactive molecules present in blood. The repeatability of this sensor was evaluated as 1.9% (RSD; for n = 10 at a 40 μmol Ldopamine level. Graphical abstract Schematic presentation of the preparation of a nanostructured composite of type SiO/C/CoO for electrooxidative sensing of dopamine.
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http://dx.doi.org/10.1007/s00604-019-3605-4DOI Listing
June 2019

Graphene-based adsorbents for the removal of toxic organic pollutants: A review.

J Environ Manage 2019 Aug 24;244:370-382. Epub 2019 May 24.

Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia. Electronic address:

The synthesis and application of efficient materials for remediation of environmental contaminants from water is an emerging area of research. Graphene has received tremendous attention in various fields due to its exceptional properties. Graphene and its derivatives have also been extensively explored for the adsorptive removal of pollutants from water. The recent trends are inclined toward functionalization of graphene-based materials to get the advantage of their improved properties. The functionalized graphene materials are efficient due to their enhanced properties resulting from synergistic effects. This article reviews the synthesis and application of graphene-based adsorbents for the removal of organic pollutants from water. A critical account is provided on synthesis methods, applications, adsorption mechanisms, the figure of merits, and removal performances. The accomplishments, limitations, challenges, and future research directions are also highlighted.
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http://dx.doi.org/10.1016/j.jenvman.2019.05.047DOI Listing
August 2019

Fabrication and performance evaluation of blood compatible hemodialysis membrane using carboxylic multiwall carbon nanotubes and low molecular weight polyvinylpyrrolidone based nanocomposites.

J Biomed Mater Res A 2019 03 28;107(3):513-525. Epub 2018 Nov 28.

Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad (CUI), Lahore Campus, Defence Road, Off Raiwind Road, Lahore, Pakistan.

This study focused to optimize the performance of polyethersulfone (PES) hemodialysis (HD) membrane using carboxylic functionalized multiwall carbon nanotubes (c-MWCNT) and lower molecular weight grade of polyvinylpyrrolidone (PVP-k30). Initially, MWCNT were chemically functionalized by acid treatment and nanocomposites (NCs) of PVP-k30 and c-MWCNT were formed and subsequently blended with PES polymer. The spectra of FTIR of the HD membranes revealed that NCs has strong hydrogen bonding and their addition to PES polymer improved the capillary system of membranes as confirmed by Field Emission Scanning Electron Microscope (FESEM) and leaching of the additive decreased to 2% and hydrophilicity improved to 22%. The pore size and porosity of NCs were also enhanced and rejection rate was achieved in the establish dialysis range (<60 kDa). The antifouling studies had shown that NCs membrane exhibited 30% less adhesion of protein with 80% flux recovery ratio. The blood compatibility assessment disclosed that NCs based membranes showed prolonged thrombin and prothrombin clotting times, lessened production of fibrinogen cluster, and greatly suppressed adhesion of blood plasma than a pristine PES membrane. The results also unveiled that PVP-k30/NCs improved the surface properties of the membrane and the urea and creatinine removal increased to 72% and 75% than pure PES membranes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 513-525, 2019.
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http://dx.doi.org/10.1002/jbm.a.36566DOI Listing
March 2019

Poly(trimesoyl chloride-melamine) grafted on palygorskite for simultaneous ultra-trace removal of methylene blue and toxic metals.

J Environ Manage 2018 Nov 18;226:358-364. Epub 2018 Aug 18.

Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia. Electronic address:

Poly(trimesoyl chloride-melamine) was grafted on palygorskite via in situ interfacial polymerization. The poly(trimesoyl chloride-melamine)-grafted palygorskite (PTMP) composite was characterized by Fourier transform infrared spectroscopy (FTIR), Energy Dispersive X-Ray Spectroscopy (EDX), N-physisorption, and scanning electron microscope (SEM). The performance of PTMP as an adsorbent was evaluated for the removal of methylene blue dye (MB) in batch and column systems. The effects of initial dye concentration, contact time, temperature and initial pH on the efficiency of MB removal were investigated. A high adsorption efficiency (≈100%) was shown by PTMP removal within 8 min with high Langmuir monolayer capacity of 64.5 mg/g at 25 °C. The mechanisms of adsorption were evaluated by isotherm and kinetic models. The activation energy E and different thermodynamic parameters, for example, ΔG, ΔS, and ΔH were calculated. The prepared composite demonstrated to be an efficient adsorbent for simultaneous removal of dye and toxic metals such as As(III), Cr(III), Mo(II), Co(III), Ni(II), and Hg(II). The dye removal was evaluated by a packed bed column system and showed an excellent adsorption performance with 90 min breakthrough at 160 ppm of initial dye concentration.
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http://dx.doi.org/10.1016/j.jenvman.2018.08.025DOI Listing
November 2018

Estimating the refractive index of oxygenated and deoxygenated hemoglobin using genetic algorithm - support vector regression model.

Comput Methods Programs Biomed 2018 Sep 21;163:135-142. Epub 2018 May 21.

Department of Computer Science, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

Background And Objectives: The refractive index of hemoglobin plays important role in hematology due to its strong correlation with the pathophysiology of different diseases. Measurement of the real part of the refractive index remains a challenge due to strong absorption of the hemoglobin especially at relevant high physiological concentrations. So far, only a few studies on direct measurement of refractive index have been reported and there are no firm agreements on the reported values of refractive index of hemoglobin due to measurement artifacts. In addition, it is time consuming, laborious and expensive to perform several experiments to obtain the refractive index of hemoglobin. In this work, we proposed a very rapid and accurate computational intelligent approach using Genetic Algorithm/Support Vector Regression models to estimate the real part of the refractive index for oxygenated and deoxygenated hemoglobin samples.

Methods: These models utilized experimental data of wavelengths and hemoglobin concentrations in building highly accurate Genetic Algorithm/Support Vector Regression model (GA-SVR).

Results: The developed methodology showed high accuracy as indicated by the low root mean square error values of 4.65 × 10 and 4.62 × 10 for oxygenated and deoxygenated hemoglobin, respectively. In addition, the models exhibited 99.85 and 99.84% correlation coefficients (r) for the oxygenated and deoxygenated hemoglobin, thus, validating the strong agreement between the predicted and the experimental results CONCLUSIONS: Due to the accuracy and relative simplicity of the proposed models, we envisage that these models would serve as important references for future studies on optical properties of blood.
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http://dx.doi.org/10.1016/j.cmpb.2018.05.029DOI Listing
September 2018

Efficiency of generic and proprietary inhibitors in mitigating Corrosion of Carbon Steel in Chloride-Sulfate Environments.

Sci Rep 2018 07 30;8(1):11443. Epub 2018 Jul 30.

Center for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

The efficiency of generic and proprietary corrosion inhibitors (based on nitrite, amine carboxylate or amino alcohol) in corrosion mitigation of carbon steel, which is exposed to concrete solutions with different amounts of chloride as well as sulfate, was studied. The corrosion protection provided by the selected corrosion inhibitors was investigated by performing a potentiodynamic polarization study. In addition, the surface morphological properties of carbon steel samples exposed to the electrolyte mixed with or without inhibitors was also evaluated by scanning electron microscopy. The potentiodynamic polarization measurements showed that the evaluated inhibitors decreased the corrosion current density by 1.6 to 6.7 times depending on the type of inhibitor and the level of sulfate concentration in the electrolyte. The performance of inhibitors based on nitrite was better than that of inhibitors based on amine carboxylate or amino alcohol. The possible mechanisms of the inhibition in the chloride plus sulfate environments are also elucidated.
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http://dx.doi.org/10.1038/s41598-018-29413-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065358PMC
July 2018