ORCID Profile
0000-0002-4800-7960
Current Organisations
Biliran Province State University
,
University of Central Asia
,
Princeton University
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Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM10379B
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2020
Publisher: American Chemical Society (ACS)
Date: 09-12-2011
DOI: 10.1021/JP2096373
Publisher: American Chemical Society (ACS)
Date: 29-04-2011
DOI: 10.1021/JP2006217
Publisher: Springer International Publishing
Date: 2020
Publisher: Elsevier BV
Date: 2016
Publisher: American Chemical Society (ACS)
Date: 13-12-2017
Abstract: Recent studies have shown that tellurium-based two-dimensional (2D) crystals undergo dramatic structural, physical, and chemical changes under ambient conditions, which adversely impact their much desired properties. Here, we introduce a diazonium molecule functionalization-based surface engineering route that greatly enhances their environmental stability without sacrificing their much desired properties. Spectroscopy and microscopy results show that diazonium groups significantly slow down the surface reactions, and consequently, gallium telluride (GaTe), zirconium telluride (ZrTe
Publisher: American Chemical Society (ACS)
Date: 12-02-2018
DOI: 10.1021/ACS.NANOLETT.7B04981
Abstract: Greenhouse gas emissions originating from fossil fuel combustion contribute significantly to global warming, and therefore the design of novel materials that efficiently capture CO
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CP44342F
Abstract: With the ever-increasing environmentally-driven demand for technologically advanced structural materials, geopolymer cement is fast becoming a viable alternative to traditional cements due to its proven engineering characteristics and the reduction in CO2 emitted during manufacturing (as much as 80% less CO2 emitted in manufacture, compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of reaction responsible for nanostructural evolution during the geopolymerisation process. Here, in situ X-ray total scattering measurements and pair distribution function (PDF) analysis are used to quantify the extent of reaction as a function of time for alkali-activated metakaolin/slag geopolymer binders, including the impact of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerisation reaction. Quantifying the reaction process in situ from X-ray PDF data collected during the initial ten hours can provide an estimate of the total reaction extent, but when combined with data obtained at longer times (128 days here) enables more accurate determination of the overall rate of reaction. To further assess the initial stages of the geopolymerisation reaction process, a pseudo-single step first order rate equation is fitted to the extent of reaction data, which reveals important mechanistic information regarding the role of free silica in the activators in the evolution of the binder systems. Hence, it is shown that in situ X-ray PDF analysis is an ideal experimental local structure tool to probe the reaction kinetics of complex reacting systems involving transitions between disordered/amorphous phases, of which geopolymerisation is an important ex le.
Publisher: International Union of Crystallography (IUCr)
Date: 06-05-2011
DOI: 10.1107/S0021889811001609
Abstract: Nuclear incoherent neutron scattering contributions present a challenge in the structural characterization of many classes of materials. This article introduces methods for the correction of nanoparticle, bulk crystalline and amorphous powder neutron scattering data with significant incoherent contributions from hydrogen, and describes the effects the corrections have on the resulting atomic pair distribution function data sets. The approach is presented in the context of the PDFgetN data-reduction program [Peterson, Gutmann, Proffen & Billinge (2000). J. Appl. Cryst. 33 , 1192].
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B922993K
Abstract: Understanding the atomic structure of complex metastable (including glassy) materials is of great importance in research and industry, however, such materials resist solution by most standard techniques. Here, a novel technique combining thermodynamics and local structure is presented to solve the structure of the metastable aluminosilicate material metakaolin (calcined kaolinite) without the use of chemical constraints. The structure is elucidated by iterating between least-squares real-space refinement using neutron pair distribution function data, and geometry optimisation using density functional modelling. The resulting structural representation is both energetically feasible and in excellent agreement with experimental data. This accurate structural representation of metakaolin provides new insight into the local environment of the aluminium atoms, with evidence of the existence of tri-coordinated aluminium. By the availability of this detailed chemically feasible atomic description, without the need to artificially impose constraints during the refinement process, there exists the opportunity to tailor chemical and mechanical processes involving metakaolin and other complex metastable materials at the atomic level to obtain optimal performance at the macro-scale.
Publisher: Elsevier BV
Date: 2016
Publisher: American Chemical Society (ACS)
Date: 07-04-2014
DOI: 10.1021/CM500470G
Publisher: International Union of Crystallography (IUCr)
Date: 02-2017
DOI: 10.1107/S1600576716018331
Abstract: The long-term durability of cement-based materials is influenced by the pore structure and associated permeability at the sub-micrometre length scale. With the emergence of new types of sustainable cements in recent decades, there is a pressing need to be able to predict the durability of these new materials, and therefore nondestructive experimental techniques capable of characterizing the evolution of the pore structure are increasingly crucial for investigating cement durability. Here, small-angle neutron scattering is used to analyze the evolution of the pore structure in alkali-activated materials over the initial 24 h of reaction in order to assess the characteristic pore sizes that emerge during these short time scales. By using a unified fitting approach for data modeling, information on the pore size and surface roughness is obtained for a variety of precursor chemistries and morphologies (metakaolin- and slag-based pastes). Furthermore, the impact of activator chemistry is elucidated via the analysis of pastes synthesized using hydroxide- and silicate-based activators. It is found that the main aspect influencing the size of pores that are accessible using small-angle neutron scattering analysis (approximately 10–500 Å in diameter) is the availability of free silica in the activating solution, which leads to a more refined pore structure with smaller average pore size. Moreover, as the reaction progresses the gel pores visible using this scattering technique are seen to increase in size.
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2018
Publisher: Elsevier BV
Date: 2015
Publisher: Shima Publishing
Date: 29-06-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR02397A
Abstract: In this work, authors report on the fundamental understanding of environmental stability of tellurium containing 2D layers. Work reports on fundamental aging mechanisms and anisotropic to isotropic transition.
Publisher: American Chemical Society (ACS)
Date: 20-05-2022
Publisher: American Chemical Society (ACS)
Date: 21-12-2011
DOI: 10.1021/CM102648N
Publisher: American Physical Society (APS)
Date: 11-10-2018
Publisher: Springer Science and Business Media LLC
Date: 22-03-2019
Publisher: AIP Publishing
Date: 23-01-2017
DOI: 10.1063/1.4975067
Abstract: The low activation energy associated with amorphous chalcogenide structures offers broad tunability of material properties with laser-based or thermal processing. In this paper, we study near-bandgap laser induced anisotropic crystallization in solution processed arsenic sulfide. The modified electronic bandtail states associated with laser irradiation lead to a distinctive photoluminescence spectrum, compared to thermally annealed amorphous glass. Laser crystalized materials exhibit a periodic subwavelength ripple structure in transmission electron microscopy experiments and show polarization dependent photoluminescence. Analysis of the local atomic structure of these materials using laboratory-based X-ray pair distribution function analysis indicates that laser irradiation causes a slight rearrangement at the atomic length scale, with a small percentage of S-S homopolar bonds converting to As-S heteropolar bonds. These results highlight fundamental differences between laser and thermal processing in this important class of materials.
Publisher: International Union of Crystallography (IUCr)
Date: 15-04-2010
DOI: 10.1107/S0021889810009155
Abstract: Differently weighted experimental scattering data have been used to extract partial or differential structure factors or pair distribution functions in studying many materials. However, this is not done routinely partly because of the lack of user-friendly software. This paper presents MIXSCAT , a new member of the DISCUS program package. MIXSCAT allows one to combine neutron and X-ray pair distribution functions and extract their respective differential functions.
Publisher: Elsevier BV
Date: 08-2019
Publisher: American Physical Society (APS)
Date: 06-07-2016
Publisher: American Chemical Society (ACS)
Date: 24-02-2023
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 08-2016
Publisher: Wiley
Date: 30-12-2022
Abstract: Understanding the mechanism of iron‐catalyzed graphitization of biomass is an important step for the large‐scale synthesis of green graphene. Although iron is known to be the most active transition metal for the catalytic graphitization of cellulose‐derived biochar, the direct effect of the iron molecular structure on the formation of highly graphitic carbon remains elusive. Here, biochar was produced from pyrolysis of iron‐impregnated cellulose at three different temperatures (1000, 1400, and 1800 °C). X‐ray diffraction, X‐ray photoelectron spectroscopy, and magnetic measurements were used to probe changes in biochar nanostructure catalyzed by the inclusion of iron. An increase of pyrolysis temperature led to an increase in the iron particle size and the degree of iron reduction, as well as the formation of larger graphitic carbon crystallite sizes, and these two attributes of iron were seen to positively affect the biochar graphitization usually challenging under 2000 °C.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 11-2016
Publisher: American Society of Civil Engineers (ASCE)
Date: 10-2019
Publisher: American Chemical Society (ACS)
Date: 05-09-2023
Publisher: Springer Science and Business Media LLC
Date: 09-08-2021
Publisher: American Chemical Society (ACS)
Date: 07-12-2016
DOI: 10.1021/ACS.JPCLETT.6B02233
Abstract: Alkali-activated materials and related alternative cementitious systems are sustainable technologies that have the potential to substantially lower the CO
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0DT01042A
Abstract: Common throughout sol-gel chemistry, including zeolite synthesis, aluminosilicate glass formation and geopolymerisation, is the process of inorganic oxide polymerisation and deprotonation. In this investigation, some of the fundamental reactions occurring during zeolite synthesis and geopolymerisation at high pH are investigated using density functional theory (DFT), and are compared with: (i) existing values reported in the literature, and (ii) new and previously published DFT-derived data for similar silicate reactions at near-neutral pH. From the results it is seen that the energetics of deprotonation and dimerisation reactions depend greatly on the pH value, and these results correlate well with existing experimental values and trends. Hence, this investigation exemplifies that an accurate replication of the solution environment is crucial for obtaining useful theoretical results for species dissolved in non-ideal environments.
Publisher: AIP Publishing
Date: 05-2023
DOI: 10.1063/5.0131778
Abstract: The Oak Ridge National Laboratory is planning to build the Second Target Station (STS) at the Spallation Neutron Source (SNS). STS will host a suite of novel instruments that complement the First Target Station’s beamline capabilities by offering an increased flux for cold neutrons and a broader wavelength bandwidth. A novel neutron imaging beamline, named the Complex, Unique, and Powerful Imaging Instrument for Dynamics (CUPI2D), is among the first eight instruments that will be commissioned at STS as part of the construction project. CUPI2D is designed for a broad range of neutron imaging scientific applications, such as energy storage and conversion (batteries and fuel cells), materials science and engineering (additive manufacturing, superalloys, and archaeometry), nuclear materials (novel cladding materials, nuclear fuel, and moderators), cementitious materials, biology/medical/dental applications (regenerative medicine and cancer), and life sciences (plant–soil interactions and nutrient dynamics). The innovation of this instrument lies in the utilization of a high flux of wavelength-separated cold neutrons to perform real time in situ neutron grating interferometry and Bragg edge imaging—with a wavelength resolution of δλ/λ ≈ 0.3%—simultaneously when required, across a broad range of length and time scales. This manuscript briefly describes the science enabled at CUPI2D based on its unique capabilities. The preliminary beamline performance, a design concept, and future development requirements are also presented.
Publisher: American Chemical Society (ACS)
Date: 14-08-2023
Publisher: Walter de Gruyter GmbH
Date: 05-2012
Publisher: Wiley
Date: 06-04-2011
Publisher: AIP Publishing
Date: 15-05-2013
DOI: 10.1063/1.4804306
Abstract: The structure of kaolinite at the atomic level, including the effect of stacking faults, is investigated using inelastic neutron scattering (INS) spectroscopy and density functional theory (DFT) calculations. The vibrational dynamics of the standard crystal structure of kaolinite, calculated using DFT (VASP) with normal mode analysis, gives good agreement with the experimental INS data except for distinct discrepancies, especially for the low frequency modes (200 – 400 cm−1). By generating several types of stacking faults (shifts in the a,b plane for one kaolinite layer relative to the adjacent layer), it is seen that these low frequency modes are affected, specifically through the emergence of longer hydrogen bonds (O–H⋯O) in one of the models corresponding to a stacking fault of −0.3151a − 0.3151b. The small residual disagreement between observed and calculated INS is assigned to quantum effects (which are not taken into account in the DFT calculations), in the form of translational tunneling of the proton in the hydrogen bonds, which lead to a softening of the low frequency modes. DFT-based molecular dynamics simulations show that anharmonicity does not play an important role in the structural dynamics of kaolinite.
Publisher: American Chemical Society (ACS)
Date: 21-10-2016
DOI: 10.1021/ACS.LANGMUIR.6B02592
Abstract: Alkali-activated materials (AAMs) are currently being pursued as viable alternatives to conventional ordinary Portland cement because of their lower carbon footprint and established mechanical performance. However, our understanding of the mesoscale morphology (∼1 to 100 nm) of AAMs and related amorphous aluminosilicate gels, including the development of the three-dimensional aluminosilicate network and nanoscale porosity, is severely limited. This study investigates the structural changes that occur during the formation of AAM gels at the mesoscale by utilizing a coarse-grained Monte Carlo (CGMC) modeling technique that exploits density functional theory calculations. The model is capable of simulating the reaction of an aluminosilicate particle in a highly alkaline solution (sodium hydroxide or sodium silicate). Two precursor morphologies have been investigated (layered alumina and silica sheets mimicking metakaolin and spherical aluminosilicate particles reminiscent of coal-derived fly ash) to determine if the precursor morphology has an impact on the structural evolution of the resulting alkali-activated aluminosilicate gel. The CGMC model can capture the three major stages of the alkali-activation process-dissolution, polycondensation, and reorganization-revealing that the dissolved silicate and aluminate species, ranging from monomers to nanoprecipitates (100s of monomers in size), exist in the pore solution of the hardened gel. The model also reveals that the silica concentration of the activating solution controls the extent of dissolution of the precursor particle. From the analysis of the aluminosilicate cluster size distributions, the mechanisms of AAM gel growth have been elucidated, revealing that Ostwald ripening occurs in systems containing free silica at the start of the reaction. On the other hand, growth of the hydroxide-activated systems (metakaolin and fly ash) occurs via the formation of intermediate-sized clusters in addition to continual growth of the largest particle. The simulation results indicate that the nature of the gel growth is not influenced by the precursor particle morphology.
Publisher: Wiley
Date: 15-07-2010
Publisher: Wiley
Date: 09-2012
DOI: 10.1002/AIC.12743
Publisher: Optica Publishing Group
Date: 11-12-2019
Abstract: Cryo-electron microscopy (cryo-EM) single particle analysis (SPA) has revolutionized biology, revealing the hydrated structure of numerous macromolecules. Yet, the potential of SPA to study inorganic materials remains largely unexplored. An area that could see great impact is solution-processed device materials, where solution changes affect everything from crystal morphology for perovskite photovoltaics to stability of photoluminescent quantum dots. While with traditional microscopy, structures underlying these effects can only be analyzed after drying, cryo-EM allows characterization of in-solution structures, revealing how features arise during processing. A top candidate for such characterization is found in chalcogenide glasses (ChGs), which researchers in the 1980s proposed take on solvent-dependent solution nanostructures whose morphologies have yet to be confirmed. Here we show that cryo-EM can directly image ChGs in solution and combine with other techniques to connect solution structure to film characteristics. Our results bring closure to a long open question in optoelectronics and establish SPA as a tool for solution-processed materials.
Publisher: American Chemical Society (ACS)
Date: 25-09-2019
Publisher: American Chemical Society (ACS)
Date: 23-04-2009
DOI: 10.1021/JP810448T
Abstract: Density functional modeling of the crystalline layered aluminosilicate mineral kaolinite is conducted, first to reconcile discrepancies in the literature regarding the exact geometry of the inner and inner surface hydroxyl groups, and second to investigate the performance of selected exchange-correlation functionals in providing accurate structural information. A detailed evaluation of published experimental and computational structures is given, highlighting disagreements in space groups, hydroxyl bond lengths, and bond angles. A major aim of this paper is to resolve these discrepancies through computations. Computed structures are compared via total energy calculations and validated against experimental structures by comparing computed neutron diffractograms, and a final assessment is performed using vibrational spectra from inelastic neutron scattering. The density functional modeling is carried out at a sufficiently high level of theory to provide accurate structure predictions while keeping computational requirements low enough to enable the use of the structures in large-scale calculations. It is found that the best functional to use for efficient density functional modeling of kaolinite using the DMol3 software package is the BLYP functional. The computed structure for kaolinite at 0 K has C1 symmetry, with the inner hydroxyl group angled slightly above the a,b plane and the inner surface hydroxyls aligned close to perpendicular to that plane.
Publisher: Springer International Publishing
Date: 2020
Publisher: American Chemical Society (ACS)
Date: 10-05-2019
Publisher: Elsevier BV
Date: 07-2021
Publisher: American Chemical Society (ACS)
Date: 20-04-2018
Publisher: Elsevier BV
Date: 12-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA00412E
Abstract: Using in situ X-ray PDF, we elucidate the crucial role of calcium in the retardation mechanism of zinc oxide.
Publisher: American Chemical Society (ACS)
Date: 04-01-2022
Abstract: More than 70% of the population without access to safe drinking water lives in remote and off-grid areas. Inspired by natural plant transpiration, we designed and tested in this study an array of scalable three-dimensional (3D) engineered trees made of natural wood for continuous water desalination to provide affordable and clean drinking water. The trees took advantage of capillary action in the wood xylems and lifted water more than 1 foot off the ground with or without solar irradiation. This process overcame some major challenges of popular solar-driven water evaporation and water harvesting, such as intermittent operation, low water production rate, and system scaling. The trade-off between energy transfer and system footprint was tackled by optimizing the interspacing between the trees. The scaled system has a ratio of surface area (vapor generation) to project area (water transport) up to 118, significantly higher than the prevailing flat-sheet design. The extensive surface area evaporated water at a temperature cooler than the surrounding air, drawing on multiple environmental energy sources including solar, wind, or ambient heat in the air and realized continuous operation. The total energy for evaporation reached over 300% of the one-sun irradiance, enabling a freshwater production rate of 4.8 L m
Publisher: Elsevier BV
Date: 06-2012
Publisher: Wiley
Date: 19-06-2017
DOI: 10.1111/JACE.15014
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CP00889F
Abstract: Determination of key amorphous–amorphous phase transformations in alkali-activated slags by combining in situ quasi-elastic neutron scattering and isothermal calorimetry.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8SM02418A
Abstract: We couple Flash NanoPrecipitation and spray drying as a scalable and versatile platform to formulate and recover amorphous nanoparticles for controlled release of hydrophobic drugs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CP07876E
Abstract: Drying-induced nanoscopic alterations to the local atomic structure of silicate-activated slag and the mitigated effects of nano-ZrO2 are elucidated using in situ X-ray pair distribution function analysis.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 07-2021
Publisher: American Chemical Society (ACS)
Date: 28-02-2018
Publisher: American Chemical Society (ACS)
Date: 10-2019
Publisher: Elsevier BV
Date: 04-2020
Publisher: American Physical Society (APS)
Date: 11-01-2021
Publisher: American Chemical Society (ACS)
Date: 12-10-2021
Publisher: Elsevier BV
Date: 02-2013
Publisher: American Chemical Society (ACS)
Date: 18-03-2010
DOI: 10.1021/JP911108D
Abstract: Understanding the atomic-level changes that occur as kaolinite is converted (thermally dehydroxylated) to metakaolin is critical to the optimization of this large-scale industrial process. Metakaolin is X-ray amorphous therefore, conventional crystallographic techniques do not reveal the changes in local structure during its formation. Local structure-based experimental techniques are useful in understanding the atomic structure but do not provide the thermodynamic information which is necessary to ensure plausibility of refined structures. Here, kaolinite dehydroxylation is modeled using density functional theory, and a stepwise methodology, where several water molecules are removed from the structure, geometry optimization is carried out, and then the process is repeated. Hence, the structure remains in an energetically and thermodynamically feasible state while transitioning from kaolinite to metakaolin. The structures generated during the dehydroxylation process are validated by comparison with X-ray and neutron pair distribution function data. Thus, this study illustrates one possible route by which dehydroxylation of kaolinite can take place, revealing a chemically, energetically, and experimentally plausible structure of metakaolin. This methodology of density functional modeling of the stepwise changes in a material is not limited in application to kaolinite or other aluminosilicates and provides an accurate representation of the local structural changes occurring in materials used in industrially important processes.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Elsevier BV
Date: 2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TA00348B
Abstract: The kinetics of reaction and the local atomic structure of carbonating C–S–H gel are characterised using high-energy synchrotron radiation.
Publisher: Wiley
Date: 11-10-2021
DOI: 10.1111/JACE.18150
Abstract: Geopolymers, as a potentially environmentally friendly alternative to Portland cement, are increasingly attracting attention in the construction industry. Various methods have been applied for customizing the properties of geopolymers and improving their commercial viability. One of the promising methods for refining the properties of geopolymers such as their toughness is the use of short fibers. The effectiveness of a high‐strength short fiber in the geopolymer matrix is largely dependent on the interfacial bonding between the fiber and its surrounding matrix. While the importance of this interfacial chemistry is highlighted in the literature, the characteristics of this bonding structure have not been fully understood. In this paper, we aim to investigate the bonding mechanism between the carbon fiber and metakaolin‐based geopolymer matrix. For the first time, the existence and nature of the chemical bonding at the interfacial region (interphase) between carbon fiber and geopolymer matrix has been revealed. X‐ray pair distribution function computed tomography (PDF‐CT), field emission‐scanning electron microscopy imaging, and nanoindentation techniques are employed to discern the chemo‐mechanical properties of the interphase. PDF‐CT results show the emergence of a new atom–atom correlation at the interfacial region (around 1.82 Å). This correlation is a characteristic of interfacial bonding between the fiber and its surrounding matrix, where the existence of chemical linkages (potentially V Al‐O‐C) between fibers and the matrix contributes to the adhesion between the two constituents making up the composite. Due to such chemical bonding, the nanomechanical properties of the interfacial region fall between that of the carbon fiber and geopolymer. The combination of advanced techniques is proved useful for enhancing our understanding of the interfacial chemistry between fibers and the binding matrix. This level of knowledge facilitates the engineering of composite systems through the manipulation of their nanostructure.
Publisher: Wiley
Date: 28-06-2018
DOI: 10.1111/JACE.15880
Publisher: Elsevier BV
Date: 03-2013
Publisher: American Chemical Society (ACS)
Date: 17-09-2015
Publisher: Rilem Publications SARL
Date: 28-01-2020
DOI: 10.21809/RILEMTECHLETT.2019.98
Abstract: Alternative (i.e., non-Portland) cements, such as alkali-activated materials, have gained significant interest from the scientific community due to their proven CO2 savings compared with Portland cement together with known short-term performance properties. However, the concrete industry remains dominated by Portland cement-based concrete. This Letter explores the technical and non-technical hurdles preventing implementation of an alternative cement, such as alkali-activated materials, in the concrete industry and discusses how these hurdles can be overcome. Specifically, it is shown that certain technical hurdles, such as a lack of understanding how certain additives affect setting of alkali-activated materials (and Portland cement) and the absence of long-term in-field performance data of these sustainable cements, can be mitigated via the use of key molecular- and nano-scale experimental techniques to elucidate dominant material characteristics, including those that control long-term performance. In the second part of this Letter the concrete industry is compared and contrasted with the electricity generation industry, and specifically the transition from one dominant technology (i.e., coal) to a erse array of energy sources including renewables. It is concluded that financial incentives and public advocacy (akin to advocacy for renewables in the energy sector) would significantly enhance uptake of alternative cements in the concrete industry.
Publisher: AIP Publishing
Date: 09-2018
DOI: 10.1063/1.5033905
Abstract: For in situ neutron scattering experiments on cementitious materials, it is of great interest to have access to a robust device which can induce uniaxial load on a given solid s le. Challenges involve selection of materials making up the apparatus that are both weak neutron scatterers and yet adequately strong to induce loads of up to a few kilonewtons on the s le. Here, the design and experimental commissioning of a novel load frame is provided with the intended use as a neutron scattering s le environment enabling time-dependent stress-induced changes to be probed in an engineering material under compression. The frame is a scaled down version of a creep apparatus, which is typically used in the laboratory to measure deformation due to creep in concrete. Components were optimized to enable 22 MPa of compressive stress to be exerted on a 1 cm diameter cement cylinder. To minimize secondary scattering signals from the load frame, careful selection of the metal components was needed. Furthermore, due to the need to maximize the wide angular detector coverage and signal to noise for neutron total scattering measurements, the frame was designed specifically to minimize the size and required number of support posts while matching s le dimensions to the available neutron beam size.
Publisher: Elsevier BV
Date: 2021
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2018
Publisher: Wiley
Date: 15-06-2017
DOI: 10.1111/JACE.14996
Location: Kazakhstan
No related grants have been discovered for Claire White.