Allen Apblett - Academia.edu (original) (raw)

Papers by Allen Apblett

Military Medicine, 2021

Introduction Military personnel are exposed to a broad range of potentially toxic compounds that ... more Introduction Military personnel are exposed to a broad range of potentially toxic compounds that can affect their health. These hazards are unpredictable because military service occurs in a wide array of uncontrolled environments. Therefore, a novel sorbent was developed that allows the fabrication of lightweight personal samplers that are both capable of sorbing an extremely wide range of organic chemical types and able to stabilize reactive compounds. Materials and Methods OSU-6, a nanoporous silica, was provided by XploSafe LLC. The sorption capacity for several volatile organic compounds, the temperatures required for thermal desorption of adsorbed compounds, and the sampling rates for targeted analytes were determined. Results The uptake capacity was found to be on average 1.5 g/g of sorbent. Analytes were not only held tightly but also could be desorbed upon heating the sorbate to temperatures below 150°C. Sampling rates for volatile organic compound by an OSU-6 sampler badge...

Bioresource Technology, 2019

Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into t... more Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into transportation fuels and chemicals. However, bio-oil applications suffer from several challenges due to its adverse properties. This study reports improving bio-oil properties through co-pyrolysis of biomass with methane over molybdenum/zinc (MoZn/ZHSM-5) and HZSM-5 catalysts that promote deoxygenation, decarbonylation, hydrogen transfer and aromatization reactions. The co-pyrolysis was conducted at 650°C and 750°C in a micro-scale reactor and a bench-scale reactor. The highest bio-oil yield, energy content, and energy yield of 53.4%, 10.2 MJ/kg, and 29.9%, respectively, were obtained with methane over MoZn/HZSM-5 at 650°C. Acids, alcohols, aldehydes, benzene derivatives, BTEXs, furans, ketones, PAHs, and phenols were detected in bio-oils while phenols dominated under most conditions. Oxygenated compounds decreased using MoZn/HZSM-5 with methane at 750°C. The results demonstrate that methane used with catalysts can reduce oxygenated compounds and improve properties and yield of bio-oil.

Topics in Catalysis, 2018

Molybdenum hydrogen bronze is a unique material that can react with both hydrogen and organic per... more Molybdenum hydrogen bronze is a unique material that can react with both hydrogen and organic peroxides and render them harmless. During the course of the reaction, the color and electrical conductivity of this material changed dramatically. Using the color change, the reaction rate of molybdenum hydrogen bronze with hydrogen peroxide has been measured colorimetrically. The reaction rate was found to be first order with respect to both the color change and concentration of hydrogen peroxide. The adsorption and dissociation mechanisms were also studied on molybdenum oxide and hydrogen bronze surfaces by means of density-functional computations. On molybdenum oxide clusters, both hydrogen peroxide and methyl hydroperoxides adsorb molecularly and do not dissociate. However, on the hydrogen bronze surfaces, both compounds can dissociate through a pathway involving either H-O or O-O bond cleavage. The O-O dissociation pathway is only energetically favorable for the methyl hydroperoxide. The chemical reaction on the molybdenum hydrogen bronze surface is made possible by the increased electron density at the surface with respect to the oxide due to the contribution from the HOMO orbital.

Chemischer Informationsdienst, 1986

ChemInform Abstract The title complex (IV) is prepared as shown by a novel high-yield route and c... more ChemInform Abstract The title complex (IV) is prepared as shown by a novel high-yield route and characterized by X-ray crystallography (space group Pbcn, Z =8). An extensive hydrogen-bonded network links the µ-OH groups to the chloride ions and lattice water molecules.

Cement and Concrete Research, 2017

Silane is a commonly used surface treatment to reduce fluid entry into the concrete matrix. This ... more Silane is a commonly used surface treatment to reduce fluid entry into the concrete matrix. This work uses micro X-ray fluorescence (μXRF) to image the presence of silane coatings in field samples and the changes made to the paste chemistry. There are many advantages that μXRF has over other imaging techniques due to the large spot size and the high energy levels. Because of this, μXRF can rapidly investigate large areas and requires minimal sample preparation. Quantitative measurements are made to show that there is a reduction in the amount of sulfur and an increase in potassium in the hydrophobic regions formed by silane coatings. These measurements provide important insights into modifications made to the concrete matrix when silane sealers are used. The mechanisms for the observed chemistry changes are discussed and a simple field or laboratory test method is presented that uses a dye to detect silane coatings.

Journal of Analytical and Applied Pyrolysis, 2016

The development of an effective process to convert bio-oil into intermediate platforms that are c... more The development of an effective process to convert bio-oil into intermediate platforms that are compatible with the existing refinery infrastructure is highly needed. To overcome the high cost of hydrogen consumption in conventional bio-oil upgrading processes, this paper reports a novel process that converts three major biomass constituents (cellulose, hemicellulose and lignin) directly into liquid fuels via pyrolysis in the presence of methane over molybdenum impregnated HZSM-5 catalysts. The carbon yield of total aromatics from lignin increased from 12.80 to 15.13 % when pyrolysis atmosphere switched from helium to methane in the presence of HZSM-5 support. However, methane was not effective in improving the aromatics yield from cellulose and hemicellulose in the presence of Mo-modified HZSM-5 catalysts. The molybdenum impregnated catalyst was found to promote deoxygenation of lignin-derived phenols. The carbon yield of polyaromatics from lignin was 5.47 % in the presence of HZSM-5 support under methane, compared to 2.61 % that obtained in the presence of Mo 2 C/HZSM-5.

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-... more This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion rates for thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125 and 0.065 mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires behaved similarly to mild reinforcing steel used in concrete structures and trigger at predictable chloride levels and are suitable for uses as trigger for corrosion. Prototype sensors, constructed using commercial radio-frequency identification tags with a section of the antenna replaced by a wire trigger, embedded in concrete and stopped responding at reproducible chloride concentrations. These results demonstrate the methodology to create successful radio-frequency identification based corrosion sensors.

Lecture Notes in Nanoscale Science and Technology, 2014

This chapter aims at developing magnetic extractants that can be utilized in conjunction with mag... more This chapter aims at developing magnetic extractants that can be utilized in conjunction with magnetic filtration devices to efficiently and economically remove a number of pollutants from aqueous solutions and mixtures. The material used for this study was based on activated carbon, where raw materials used for the development of high surface area-activated carbon were modified to produce novel magnetically active activated carbons (MACs). The unique properties and adsorption capacity of these materials allowed their application in the extraction of hydrocarbons from water and in breaking oil in water emulsions. An investigation on the ability of MACs for the removal of 4,6-dinitro-o-cresol pesticide, Congo red, and decane is presented.

Phosphorus, Sulfur, and Silicon and the Related Elements, 2014

ABSTRACT

MRS Proceedings, 1991

ABSTRACTReaction of boehmite, [AI(O)(OH)]n, with an excess of carboxylic acid (HO2CR) results in ... more ABSTRACTReaction of boehmite, [AI(O)(OH)]n, with an excess of carboxylic acid (HO2CR) results in the formation of the carboxy substituted alumoxanes, [AI(O)x(OH)y(O2CR)z)]n where 2x + y + z = 3 and R = alkyl substituents. The alumoxanes have been fully characterized by SEM, elemental analysis, IR and multinuclear NMR spectroscopy. The physical properties of the alumoxanes are highly dependent on the identity of R, and range from insoluble crystalline powders, e.g. R = CH3, to powders which readily form solutions or gels in hydrocarbon solvents, e.g. R = C5H11. All of the alumoxanes decompose under mild thermolysis to yield γ-alumina.

Progress in Organic Coatings, 2004

... content solutions (17–45%) showed excellent mechanical strength, good adhesion, and provided ... more ... content solutions (17–45%) showed excellent mechanical strength, good adhesion, and provided ... In the present study, we have prepared Ormosil coatings containing 0.1–16.6 ... Changes in corrosion resistance and structure occurring during coating degradation were analyzed ...

ACS Applied Materials & Interfaces, 2014

International Journal of Polymer Science, 2010

Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for ... more Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characteri...

ClO2 is of interest because of it's capability to kill biological hazards such as E. coli an... more ClO2 is of interest because of it's capability to kill biological hazards such as E. coli and mold. However, ClO2 is a toxic, reactive gas that must be generated at the point-of-use. Gas storage is not possible due to the possibility of an explosion. The need to detect the amount of ClO2 at the point-of-use necessitates a low cost sensor. A low-cost spectrophotometric sensor based on a broad-band light source, a photodiode detector and a band-pass filter is proposed. To verify the design, precise determinations of the gas-phase cross-section and characterization of the optical components are necessary. Known concentrations of ClO2(g) are prepared using the equilibrium relationship between an aqueous solution and the gas phase. The aqueous solutions are obtained by generating the gas via a chemical reaction and passing it through water. The concentrations of the aqueous solutions are then determined by chemical titration and UV-visible absorption measurements. For the solutions,...

Phosphorus, Sulfur, and Silicon and the Related Elements, 1989

AbstracL The six-membered ring system RCN(NSC1h (R= IBu, CC13, Me2N, Et2N, iPr2N) can be prepared... more AbstracL The six-membered ring system RCN(NSC1h (R= IBu, CC13, Me2N, Et2N, iPr2N) can be prepared by a cycloaddition reaction of the free nimle, RCN, with ~yclo-(NSCl)~ at mom temperature. This reaction is slow for R= [Bu and CCl,, but it can be accelerated by UV light. The sixmembered rings are converted to five-membered rings RCN2S2+ C1-by thermolysis. By varying the conditions of the cycloaddition reaction, 1,3-(RCN),(NSCl), (R= Me2N, Et2N) and 13-RCN(NSN),SCl can be obtained.

Journal of Materials in Civil Engineering, 2014

ABSTRACT This paper describes the results of an experimental study that uses radio frequency iden... more ABSTRACT This paper describes the results of an experimental study that uses radio frequency identification (RFID) technology to detect cracking in concrete elements. A RFID-based sensor is used to monitor the change in electrical resistance that occurs in conductive materials applied to the surface of the concrete. When the concrete substrate is strained, the conductive material at the surface is stretched, and its electrical resistance increases. If the concrete substrate is strained to the point where it cracks, the conductive material at the surface also cracks, causing its electrical resistance to increase by orders of magnitude. This paper describes how this increase in electrical resistance attributable to cracking can be detected wirelessly by RFID technology. To experimentally illustrate the application of this technology, an RFID-based sensor and conductive surface materials are used to detect cracking in the restrained ring test. The experimental results indicate that this technology can be easily implemented and successfully used for wireless crack detection in concrete and reinforced concrete members. The technology that is described in this paper is not limited to the laboratory environment and can be easily extended to field applications.

Journal of Materials in Civil Engineering, 2014

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-... more This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion of thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125-and 0.065-mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires are suitable for use as triggers for corrosive salts. They behaved similarly to mild reinforcing steel used in concrete structures and their resistance increased significantly at predictable chloride levels. Prototype sensors, constructed using commercial radio frequency identification tags with a section of the antenna replaced by a wire trigger, were embedded in concrete. These results demonstrate the methodology to create successful radio frequency identification based sensors for the egress of corrosive agents, such as chlorides, into concrete.

Journal of Environmental Monitoring, 2011

The enduring effects of injected materials used for the remediation of chlorinated solvents were ... more The enduring effects of injected materials used for the remediation of chlorinated solvents were examined. Approximately two years previous to this study, four different remediation methods were tested in an area located southeast of Oklahoma City, OK. These methods included bioremediation under both anaerobic and aerobic conditions and chemical remediation using Fenton's reagent or KMnO(4). A series of water quality tests performed in this investigation revealed that the bioremediation processes did not introduce any unexpected chemistry. However, the wells that were treated anaerobically still had water with a negative oxidation-reduction potential and had no recontamination with migrating trichloroethylene as opposed to the aerobic wells that had both positive redox potentials and trichloroethylene present. Also, chemical treatment using Fenton's reagent did not result in any long-term changes in the well chemistry, with the exception of inducing a slight acidity. This is due to the facts that addition of iron into the aquifer that is already in contact with iron-rich clay soil had little long-term effects and the radical chemistry with hydrogen peroxide is short-lived due to its reactivity. KMnO(4)-based remediation results in deposition of new materials containing manganese in elevated oxidation states that may provide long-term protection against the build up of chlorinated organic compounds.

Military Medicine, 2021

Introduction Military personnel are exposed to a broad range of potentially toxic compounds that ... more Introduction Military personnel are exposed to a broad range of potentially toxic compounds that can affect their health. These hazards are unpredictable because military service occurs in a wide array of uncontrolled environments. Therefore, a novel sorbent was developed that allows the fabrication of lightweight personal samplers that are both capable of sorbing an extremely wide range of organic chemical types and able to stabilize reactive compounds. Materials and Methods OSU-6, a nanoporous silica, was provided by XploSafe LLC. The sorption capacity for several volatile organic compounds, the temperatures required for thermal desorption of adsorbed compounds, and the sampling rates for targeted analytes were determined. Results The uptake capacity was found to be on average 1.5 g/g of sorbent. Analytes were not only held tightly but also could be desorbed upon heating the sorbate to temperatures below 150°C. Sampling rates for volatile organic compound by an OSU-6 sampler badge...

Bioresource Technology, 2019

Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into t... more Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into transportation fuels and chemicals. However, bio-oil applications suffer from several challenges due to its adverse properties. This study reports improving bio-oil properties through co-pyrolysis of biomass with methane over molybdenum/zinc (MoZn/ZHSM-5) and HZSM-5 catalysts that promote deoxygenation, decarbonylation, hydrogen transfer and aromatization reactions. The co-pyrolysis was conducted at 650°C and 750°C in a micro-scale reactor and a bench-scale reactor. The highest bio-oil yield, energy content, and energy yield of 53.4%, 10.2 MJ/kg, and 29.9%, respectively, were obtained with methane over MoZn/HZSM-5 at 650°C. Acids, alcohols, aldehydes, benzene derivatives, BTEXs, furans, ketones, PAHs, and phenols were detected in bio-oils while phenols dominated under most conditions. Oxygenated compounds decreased using MoZn/HZSM-5 with methane at 750°C. The results demonstrate that methane used with catalysts can reduce oxygenated compounds and improve properties and yield of bio-oil.

Topics in Catalysis, 2018

Molybdenum hydrogen bronze is a unique material that can react with both hydrogen and organic per... more Molybdenum hydrogen bronze is a unique material that can react with both hydrogen and organic peroxides and render them harmless. During the course of the reaction, the color and electrical conductivity of this material changed dramatically. Using the color change, the reaction rate of molybdenum hydrogen bronze with hydrogen peroxide has been measured colorimetrically. The reaction rate was found to be first order with respect to both the color change and concentration of hydrogen peroxide. The adsorption and dissociation mechanisms were also studied on molybdenum oxide and hydrogen bronze surfaces by means of density-functional computations. On molybdenum oxide clusters, both hydrogen peroxide and methyl hydroperoxides adsorb molecularly and do not dissociate. However, on the hydrogen bronze surfaces, both compounds can dissociate through a pathway involving either H-O or O-O bond cleavage. The O-O dissociation pathway is only energetically favorable for the methyl hydroperoxide. The chemical reaction on the molybdenum hydrogen bronze surface is made possible by the increased electron density at the surface with respect to the oxide due to the contribution from the HOMO orbital.

Chemischer Informationsdienst, 1986

ChemInform Abstract The title complex (IV) is prepared as shown by a novel high-yield route and c... more ChemInform Abstract The title complex (IV) is prepared as shown by a novel high-yield route and characterized by X-ray crystallography (space group Pbcn, Z =8). An extensive hydrogen-bonded network links the µ-OH groups to the chloride ions and lattice water molecules.

Cement and Concrete Research, 2017

Silane is a commonly used surface treatment to reduce fluid entry into the concrete matrix. This ... more Silane is a commonly used surface treatment to reduce fluid entry into the concrete matrix. This work uses micro X-ray fluorescence (μXRF) to image the presence of silane coatings in field samples and the changes made to the paste chemistry. There are many advantages that μXRF has over other imaging techniques due to the large spot size and the high energy levels. Because of this, μXRF can rapidly investigate large areas and requires minimal sample preparation. Quantitative measurements are made to show that there is a reduction in the amount of sulfur and an increase in potassium in the hydrophobic regions formed by silane coatings. These measurements provide important insights into modifications made to the concrete matrix when silane sealers are used. The mechanisms for the observed chemistry changes are discussed and a simple field or laboratory test method is presented that uses a dye to detect silane coatings.

Journal of Analytical and Applied Pyrolysis, 2016

The development of an effective process to convert bio-oil into intermediate platforms that are c... more The development of an effective process to convert bio-oil into intermediate platforms that are compatible with the existing refinery infrastructure is highly needed. To overcome the high cost of hydrogen consumption in conventional bio-oil upgrading processes, this paper reports a novel process that converts three major biomass constituents (cellulose, hemicellulose and lignin) directly into liquid fuels via pyrolysis in the presence of methane over molybdenum impregnated HZSM-5 catalysts. The carbon yield of total aromatics from lignin increased from 12.80 to 15.13 % when pyrolysis atmosphere switched from helium to methane in the presence of HZSM-5 support. However, methane was not effective in improving the aromatics yield from cellulose and hemicellulose in the presence of Mo-modified HZSM-5 catalysts. The molybdenum impregnated catalyst was found to promote deoxygenation of lignin-derived phenols. The carbon yield of polyaromatics from lignin was 5.47 % in the presence of HZSM-5 support under methane, compared to 2.61 % that obtained in the presence of Mo 2 C/HZSM-5.

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-... more This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion rates for thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125 and 0.065 mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires behaved similarly to mild reinforcing steel used in concrete structures and trigger at predictable chloride levels and are suitable for uses as trigger for corrosion. Prototype sensors, constructed using commercial radio-frequency identification tags with a section of the antenna replaced by a wire trigger, embedded in concrete and stopped responding at reproducible chloride concentrations. These results demonstrate the methodology to create successful radio-frequency identification based corrosion sensors.

Lecture Notes in Nanoscale Science and Technology, 2014

This chapter aims at developing magnetic extractants that can be utilized in conjunction with mag... more This chapter aims at developing magnetic extractants that can be utilized in conjunction with magnetic filtration devices to efficiently and economically remove a number of pollutants from aqueous solutions and mixtures. The material used for this study was based on activated carbon, where raw materials used for the development of high surface area-activated carbon were modified to produce novel magnetically active activated carbons (MACs). The unique properties and adsorption capacity of these materials allowed their application in the extraction of hydrocarbons from water and in breaking oil in water emulsions. An investigation on the ability of MACs for the removal of 4,6-dinitro-o-cresol pesticide, Congo red, and decane is presented.

Phosphorus, Sulfur, and Silicon and the Related Elements, 2014

ABSTRACT

MRS Proceedings, 1991

ABSTRACTReaction of boehmite, [AI(O)(OH)]n, with an excess of carboxylic acid (HO2CR) results in ... more ABSTRACTReaction of boehmite, [AI(O)(OH)]n, with an excess of carboxylic acid (HO2CR) results in the formation of the carboxy substituted alumoxanes, [AI(O)x(OH)y(O2CR)z)]n where 2x + y + z = 3 and R = alkyl substituents. The alumoxanes have been fully characterized by SEM, elemental analysis, IR and multinuclear NMR spectroscopy. The physical properties of the alumoxanes are highly dependent on the identity of R, and range from insoluble crystalline powders, e.g. R = CH3, to powders which readily form solutions or gels in hydrocarbon solvents, e.g. R = C5H11. All of the alumoxanes decompose under mild thermolysis to yield γ-alumina.

Progress in Organic Coatings, 2004

... content solutions (17–45%) showed excellent mechanical strength, good adhesion, and provided ... more ... content solutions (17–45%) showed excellent mechanical strength, good adhesion, and provided ... In the present study, we have prepared Ormosil coatings containing 0.1–16.6 ... Changes in corrosion resistance and structure occurring during coating degradation were analyzed ...

ACS Applied Materials & Interfaces, 2014

International Journal of Polymer Science, 2010

Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for ... more Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characteri...

ClO2 is of interest because of it's capability to kill biological hazards such as E. coli an... more ClO2 is of interest because of it's capability to kill biological hazards such as E. coli and mold. However, ClO2 is a toxic, reactive gas that must be generated at the point-of-use. Gas storage is not possible due to the possibility of an explosion. The need to detect the amount of ClO2 at the point-of-use necessitates a low cost sensor. A low-cost spectrophotometric sensor based on a broad-band light source, a photodiode detector and a band-pass filter is proposed. To verify the design, precise determinations of the gas-phase cross-section and characterization of the optical components are necessary. Known concentrations of ClO2(g) are prepared using the equilibrium relationship between an aqueous solution and the gas phase. The aqueous solutions are obtained by generating the gas via a chemical reaction and passing it through water. The concentrations of the aqueous solutions are then determined by chemical titration and UV-visible absorption measurements. For the solutions,...

Phosphorus, Sulfur, and Silicon and the Related Elements, 1989

AbstracL The six-membered ring system RCN(NSC1h (R= IBu, CC13, Me2N, Et2N, iPr2N) can be prepared... more AbstracL The six-membered ring system RCN(NSC1h (R= IBu, CC13, Me2N, Et2N, iPr2N) can be prepared by a cycloaddition reaction of the free nimle, RCN, with ~yclo-(NSCl)~ at mom temperature. This reaction is slow for R= [Bu and CCl,, but it can be accelerated by UV light. The sixmembered rings are converted to five-membered rings RCN2S2+ C1-by thermolysis. By varying the conditions of the cycloaddition reaction, 1,3-(RCN),(NSCl), (R= Me2N, Et2N) and 13-RCN(NSN),SCl can be obtained.

Journal of Materials in Civil Engineering, 2014

ABSTRACT This paper describes the results of an experimental study that uses radio frequency iden... more ABSTRACT This paper describes the results of an experimental study that uses radio frequency identification (RFID) technology to detect cracking in concrete elements. A RFID-based sensor is used to monitor the change in electrical resistance that occurs in conductive materials applied to the surface of the concrete. When the concrete substrate is strained, the conductive material at the surface is stretched, and its electrical resistance increases. If the concrete substrate is strained to the point where it cracks, the conductive material at the surface also cracks, causing its electrical resistance to increase by orders of magnitude. This paper describes how this increase in electrical resistance attributable to cracking can be detected wirelessly by RFID technology. To experimentally illustrate the application of this technology, an RFID-based sensor and conductive surface materials are used to detect cracking in the restrained ring test. The experimental results indicate that this technology can be easily implemented and successfully used for wireless crack detection in concrete and reinforced concrete members. The technology that is described in this paper is not limited to the laboratory environment and can be easily extended to field applications.

Journal of Materials in Civil Engineering, 2014

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-... more This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion of thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125-and 0.065-mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires are suitable for use as triggers for corrosive salts. They behaved similarly to mild reinforcing steel used in concrete structures and their resistance increased significantly at predictable chloride levels. Prototype sensors, constructed using commercial radio frequency identification tags with a section of the antenna replaced by a wire trigger, were embedded in concrete. These results demonstrate the methodology to create successful radio frequency identification based sensors for the egress of corrosive agents, such as chlorides, into concrete.

Journal of Environmental Monitoring, 2011

The enduring effects of injected materials used for the remediation of chlorinated solvents were ... more The enduring effects of injected materials used for the remediation of chlorinated solvents were examined. Approximately two years previous to this study, four different remediation methods were tested in an area located southeast of Oklahoma City, OK. These methods included bioremediation under both anaerobic and aerobic conditions and chemical remediation using Fenton's reagent or KMnO(4). A series of water quality tests performed in this investigation revealed that the bioremediation processes did not introduce any unexpected chemistry. However, the wells that were treated anaerobically still had water with a negative oxidation-reduction potential and had no recontamination with migrating trichloroethylene as opposed to the aerobic wells that had both positive redox potentials and trichloroethylene present. Also, chemical treatment using Fenton's reagent did not result in any long-term changes in the well chemistry, with the exception of inducing a slight acidity. This is due to the facts that addition of iron into the aquifer that is already in contact with iron-rich clay soil had little long-term effects and the radical chemistry with hydrogen peroxide is short-lived due to its reactivity. KMnO(4)-based remediation results in deposition of new materials containing manganese in elevated oxidation states that may provide long-term protection against the build up of chlorinated organic compounds.