Yes / This paper presents an experimental study into the axial compressive behaviour of self-compacting concrete filled elliptical steel tube columns. In total, ten specimens, including two empty columns, with various lengths, section sizes and concrete strengths were tested to failure. The experimental results indicated that the failure modes of the self-compacting concrete filled elliptical steel tube columns with large slenderness ratio were dominated by global buckling. Furthermore, the composite columns possessed higher critical axial compressive capacities compared with their hollow section companions due to the composite interaction. However, due to the large slenderness ratio of the test specimens, the change of compressive strength of concrete core did not show significant effect on the critical axial compressive capacity of concrete filled columns although the axial compressive capacity increased with the concrete grade increase. The comparison between the axial compressive load capacities obtained from experimental study and prediction using simple methods provided in Eurocode 4 for concrete-filled steel circular tube columns showed a reasonable agreement. The experimental results, analysis and comparison presented in this paper clearly support the application of self-compacting concrete filled elliptical steel tube columns in construction engineering practice.

Yes / This paper focuses on monitoring the evolution of lime-clay reactions using geotechnical parameters as a function of lime content and environmental temperature. Lime contents of 5, 7, 9, 11 and 13% by dry weight of expansive clay powder were added to prepare lime-clay specimens. The specimens were prepared at the same dry unit weight of 12.16 kN/m3 and moisture content of 40% except for tests aimed at the determination of dry unit weight as a function of mellowing period. Prepared specimens were mellowed or cured at two different ambient temperatures of 20 °C and 40 °C. Results attained from Unconfined Compressive Strength and permeability tests were employed to assess the impact of lime content on the mechanical and hydraulic properties of lime treated expansive clays. The results revealed that at the beginning, the rate of strength gain is remarkably fast for a particular period of time which is dependent on lime content. Furthermore, the strength gain on specimens cured at 40 °C is 8 times higher than that observed on specimens cured at 20 °C which highlights significant effect for the environmental temperature on accelerating the chemical reactions. Reduced dry unit weight due to increased resistance to compactability is observable with increasing lime content and higher environmental temperature. Accelerated pozzolanic reaction at higher environmental temperature resulted in permeability coefficient of specimens mellowed for 24 h at 40 °C to be higher than those mellowed at 20 °C. The results also highlighted that the permeability coefficient would be relatively stable when expansive clays were treated with small amounts of lime e.g. 5%.

Yes / Construction and demolition waste (CDW) has been recently identified as a potential aluminosilicate source for geopolymers. However, the available research has mainly focused on developing CDW-based geopolymer pastes and mortars, while studies on geopolymer concretes sourced from CDW have been very limited. Thus, the current study aimed at experimentally identifying different CDW materials suitable for producing geopolymer concretes. Additionally, the study analysed the mechanical, microstructural, and environmental properties of CDW- based geopolymer concrete produced. In this regard, the effect of relevant parameters on the compressive strength development of CDW-based geopolymer concretes was comprehensively investigated, including those related to precursor types/fineness, alkali activator solution, aggregate type/size and curing regimes. Microstructural analyses were also conducted on the selected samples (100% brick waste, 100% tile waste, 100% concrete waste and 75% brick waste + 25% GGBS). Finally, the environmental impact of geopolymer concrete was assessed and compared with similar traditional concrete. Results showed that employing CDWs alone is not suitable to achieve sufficient strengths under all curing regimes. However, the inclusion of 25% GGBS significantly improved the strength performance of CDW-based geopolymer concrete, in comparison to other supplementary cementitious materials (SCMs) such as Class-C fly ash and calcium hydroxide. The particle size of CDWs and concentration of alkaline activators highly affect the performance of CDW-based geopolymer concretes. Utilization of CDWs with particles finer than 75 μm and high concentrations of NaOH (12 M) is recommended to achieve good performance. The results also indicate that almost similar energy is needed for producing CDW-based geopolymer and OPC-based traditional concrete, whereas a huge reduction in CO2 emission (∼40%) was estimated in the case of geopolymers. The outcomes of the current study are expected to contribute to the advancement of geopolymer concrete derived from CDW in addition to providing valuable insights into this type of concrete for practitioners and academics.

Yes / This article aims to investigate the flowability, physical, mechanical, and durability properties of metakaolin (MK)-added colored cement mortars exposed to the effects of H2SO4 sulfuric acid (SA) and HNO3 nitric acid (NA). MK was used in 20% replacement with cement, and yellow (YP) and red pigments (RP) were added to the mixtures at 1% and 3% of the cement by weight. According to the results, although MK reduced the workability and, therefore, the flow diameter (FD) of mortars, thanks to the void-filling feature of MK, filling the voids in the microstructure caused the samples' apparent porosity (AP) and relative dynamic modulus of elasticity (RDME) to decrease. Additionally, MK significantly improved the residual compressive (RCS) and residual flexural strengths (RFS) of the samples thanks to the calcium-silicate-hydrate (C-S-H) bonds it formed in the interior structure, owing to its high pozzolanic efficiency. Moreover, this improvement of MK is more remarkable in samples that remain subject to SA and NA attacks for more time. Furthermore, while YP reduces the workability of mortars and, therefore, the FD value due to its needle-tipped grain structure, RP increases the FD value of the mortars with its spherical grain structure. However, YP and RP contributed to reducing the AP of the samples and increasing RCS and RFS capacities at a meager rate by showing a micro-filling effect. In addition, there were significant increases in the total color changes (E) of YP and RP-added colored mortar samples, especially after longer SA and NA attacks. / This paper is financially supported by the University of Van Yüzüncü Yil, Department of BAP, within the scope of the CDS-2023-10468 project. / The full-text of this article will be released for public view at the end of the publisher embargo on 4 May 2025.

<p dir="ltr">In nuclear reactors, enhancing safety via active monitoring of conditions and automation of routine aspects of plant operation require sensors to be integrated into the nuclear reactor system. Incorporating sensors that are compatible with advanced reactor environments can increases capital cost significantly. Additionally, many locations in the system that contain valuable data are wholly inaccessible to current sensor technology. Model order reduction allows critical information about sensor placement and experiment design to be distilled from fully resolved fluid mechanics simulation results. In many cases, sensed information in conjunction with reduced order models can also be used to regenerate full field variables. Previous work has demonstrated projection of sensed pressure data from one spatial domain to another via proper orthogonal decomposition (POD). In this work, the POD inferencing method is extended to the modeling and compressive sensing of temperature, a scalar field variable, and the modeling of pressure from sensed temperature data.</p><p dir="ltr">The method is applied to the problem of flow over a cylinder with heat generation at the cylinder boundary with Pr>>1, Pr\~1, and Pr<<1. The model is trained on pressure and temperature data from simulations. Field reconstructions are then generated using data from selected sensors and the POD model. Finally, the reconstruction performance is evaluated and presented as a function of Prandtl number, sensor count, and mode count. The predicted trend of increasing reconstruction accuracy with decreasing Prandtl number is confirmed and a Prandtl number/sensor count reconstruction performance matrix is presented. In order to examine the efficacy of this algorithm in transfer learning from one scalar field to another scalar field, temperature data sensors are used to predict pressure field information.</p><p dir="ltr">Three empirical sensor location selection techniques are developed and compared: mode-based, random sampling, and boundary-layer based. The random sampling yielded the highest accuracy but required significant computational resources. The mode-based approach, despite its lower accuracy, is used in the analysis of the POD ROM for its explainability and compatibility with existing studies.</p><p dir="ltr">It is shown that the lower Prandtl number flows require fewer sensors and modes for accurate temperature reconstruction, with models utilizing more modes generally outperforming those with fewer as expected. Notably, reconstruction accuracy for temperature and pressure was comparable in high Prandtl number fluids, but in moderate and low Prandtl number fluids, increased thermal diffusion led to smoother temperature gradients and enhanced reconstruction performance with fewer modes.</p><p dir="ltr">This study extends prior work by applying POD ROM techniques to the sparse sensing of temperature. It considers the effect of varying thermal diffusivity between materials and develops trends in accuracy between them. Furthermore, it introduces cross-scalar projection to this technique as a form virtual sensing. Additionally, the question of sensor placement is addressed in greater detail than in prior literature and alternative methods are evaluated. This study confirms the potential of POD ROMs for cross-scalar data projection and presents novel sensor selection techniques while providing insights into optimal conditions for their application.</p><p><br></p>

In the past two decades, myriad algorithms to elucidate the characteristics and dynamics of molecular systems have been developed for quantum computers. In this dissertation, we explore how these algorithms can be adapted to other fields, both to closely related subjects such as materials science, and more surprising subjects such as information theory. Special emphasis is placed on the Variational Quantum Eigensolver algorithm adapted to solve band structures of a periodic system; three distinct implementations are developed, each with its own advantages and disadvantages. We also see how unitary quantum circuits designed to model individual electron excitations within a molecule can be modified to prepare a quantum states strictly orthogonal to a space of known states, an important component to solve problems in thermodynamics and spectroscopy. Finally, we see how the core behavior in several quantum algorithms originally developed for quantum chemistry can be adapted to implement compressive sensing, a protocol in information theory for extrapolating large amounts of information from relatively few measurements. This body of work demonstrates that quantum algorithms developed to study molecules have immense interdisciplinary uses in fields as varied as materials science and information theory.

Photos captured in the shortwave infrared (SWIR) spectrum are interesting in military applications because they are independent of what time of day the pic- ture is captured because the sun, moon, stars and night glow illuminate the earth with short-wave infrared radiation constantly. A major problem with today’s SWIR cameras is that they are very expensive to produce and hence not broadly available either within the military or to civilians. Using a relatively new tech- nology called compressive sensing (CS), enables a new type of camera with only a single pixel sensor in the sensor (a SPC). This new type of camera only needs a fraction of measurements relative to the number of pixels to be reconstructed and reduces the cost of a short-wave infrared camera with a factor of 20. The camera uses a micromirror array (DMD) to select which mirrors (pixels) to be measured in the scene, thus creating an underdetermined linear equation system that can be solved using the techniques described in CS to reconstruct the im- age. Given the new technology, it is in the Swedish Defence Research Agency (FOI) interest to evaluate the potential of a single pixel camera. With a SPC ar- chitecture developed by FOI, the goal of this thesis was to develop methods for sampling, reconstructing images and evaluating their quality. This thesis shows that structured random matrices and fast transforms have to be used to enable high resolution images and speed up the process of reconstructing images signifi- cantly. The evaluation of the images could be done with standard measurements associated with camera evaluation and showed that the camera can reproduce high resolution images with relative high image quality in daylight.

No description available.

Seismic-resistant steel eccentrically braced frames (EBFs) are designed so that that yielding during earthquake loading is restricted primarily to the ductile links. To achieve this behavior, all members other than the link are designed to be stronger than the link, i.e. to develop the capacity of the link. However, satisfying these capacity design requirements for the beam segment outside of the link can be difficult in the overall design process of an EBF. In some cases, it may be necessary to make significant changes to the configuration of the EBF in order to satisfy beam design requirements. If this discovery is made late in the design process, such changes can be costly. The overall goal of this research was to develop guidelines for preliminary design of EBFs that will result in configurations where the beam is likely to satisfy capacity design requirements. Simplified approximate equations were developed to predict the axial force and moment in the beam segment outside of the link when link ultimate strength is developed. These equations, although approximate, provided significant insight into variables that affect capacity design of the beam. These equations were then used to conduct an extensive series of parametric studies on a wide variety of EBF configurations. The results of these studies show that the most important variables affecting beam design are 1) the nondimensional link length, 2) the ratio of web area to total area for the wide flange section used for the beam and link, 3) the angle between the brace and the beam, and 4) the flexural stiffness of the brace relative to the beam. Recommendations are provided for selection of values for these variables in preliminary design. / text

Šiame baigiamajame magistro darbe nagrinėjama gruntbetonio savybių priklausomybė nuo grunto sudėties. Atlikta porų injekcijos ir srautinės injekcijos teorijos apžvalga, išdėstytos šių metodų atlikimo sekos, panaudojimo sritys bei aptartos srautinėmis injekcijomis suformuotų gruntbetoninių kolonų fizikinės savybės. Baigiamojo magistro darbo teorinėje dalyje pateikiama pagrindų stiprinimo injekcijomis apžvalga. Aptariami jų ypatumai, technologijos bei medžiagos, pateikiami kokybės kontrolės metodai, nagrinėjamos dažniausiai kylančios problemos ir jų sprendimo būdai. Eksperimentinėje dalyje nagrinėjama, kokį poveikį priemaišos daro gruntbetonio savybėms. Buvo atliekami laboratoriniai tyrimai, nagrinėjama grunbetonio savybių priklausomybė nuo grunto sudėties. Aprašomi gauti rezultatai, atliekama jų analizė, suformuluojamos išvados. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, eksperimentiniai tyrimai, išvados, literatūros sąrašas ir priedai. Darbo apimtis – 118 p. teksto be priedų, 35 p. priedų, 78 paveikslėliai, 39 lentelės, 44 bibliografiniai šaltiniai. / This master thesis examines soilerete properties dependence on the composition of the soil. Carried out in pairs at the injection stream and an overview of the theory of the injection set forth in the execution sequence of these methods, fields, and discussed the use of injection-formed soilrets thanks to the physical properties of columns. Master's thesis in theoretical basis for the strengthening of the Review of the injection. Discuss their features, technology and materials, the quality control methods, addresses the most common problems and their solutions. The experimental section deals with the impact of the pollution for soileret properties. Was carried out laboratory tests analyzed in the analysis, formulation of conclusions. The work consists of seven parts: introduction, literature review, experimental studies, conclusions, references, published articles and accessories. Thesis consist of: 118 p. text without appendixes, 35 p.appendixes, 78 pictures, 39 tables, 44 bibliographical entries.