Use of three-force member concept for rigid bodies whenever possible, to circumvent the more taxing use of equilibrium equations has been long-established. However, most students fail to reap its ...benefits due to a number of reasons, including the fact that its importance is hardly emphasized to them; skills and details needed for the concept are missing in many undergraduate textbooks on Statics. This paper revisits and solidifies the understanding of three-force member in exploiting its potential for solving difficult problems. The paper addresses one of the most frequent students' questions and concerns that the authors have faced in their experience of teaching Statics. This topic is revitalized herein, and its importance emphasized, to obviate the possibility of students' wrong impression about its obsoleteness, by presenting detailed material in a pedagogical manner to serve as an addendum to any textbook for university undergraduate course in Statics. This serves as a good reference for both instructors and students in the course and eliminates their difficulty in accessing a concise document on the topic. Four examples, with increasing complexity, are solved where quicker and easier steps using three-force member concept are compared with the lengthier and relatively more difficult use of equilibrium equations.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Hyalinizing trabecular tumor (HTT), a rare low-malignant-potential thyroid neoplasm, is usually treated with conservative surgery. However, cytomorphological diagnosis of HTT is challenging due to ...the significant overlap of nuclear features with more common malignancies such as papillary thyroid carcinoma (PTC), which usually requires more radical surgical intervention. To avoid unnecessary overtreatment, a precise diagnosis of HTT is therefore essential. Advances in molecular diagnostics provide the opportunity to overcome the limitations of cytological analysis. We present a case of HTT in a 71-year-old male who was initially suspected to be PTC based on cytopathology. However, further molecular analysis revealed PAX8::GLIS3 gene fusion, classifying the lesion as HTT and preventing surgical overtreatment. We discuss the diagnostic pitfall of cytopathology in HTT and suggest using emerging molecular genetic tools to avoid it.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
Performance of the existing design provisions on fiber reinforced polymer (FRP) reinforced concrete (RC) – FRP-RC – deep beams without stirrups appear to be less robust than when applied to slender ...geometries. This, coupled with the need for making physical sense of the shear behavior of FRP-RC elements, motivates the present work to extend the Critical Shear Crack Theory to the former, given that the original theory forms the basis for the Swiss design code and the new draft of the Eurocode for shear and punching shear designs. Attributes of deep members such as the geometry of the critical shear crack, the critical section location and the arch action are incorporated into the modified model using special functions and parameters obtained via nonlinear regression, resulting in a model justified with more mechanics and less empiricism than most of the existing design equations. A comprehensive database of deep FRP-RC beams without stirrups was compiled and its behavior thoroughly critiqued with respect to various effective shear strength parameters. The database artifacts and their connection to the less satisfactory performance of the codes/guidelines are discussed. Performance of the developed model was successfully validated using both the training data and blind simulation against the database.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Reducing the production costs of clean energy carriers such as hydrogen through scalable water electrolysis is a potential solution for advancing the hydrogen economy. Among the various material ...candidates, our group demonstrated transition-metal-based materials with tunable electronic characteristics, various phases, and earth-abundance. Herein, electrochemical water oxidation using Cu
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as a non-precious metallic electrocatalyst via a hydrothermal approach is reported. The water-splitting performance of all the fabricated electrocatalysts was evaluated after direct growth on a stainless-steel substrate. The electrochemically tuned Cu
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catalyst exhibited a reduced overpotential of 128 mV and provided a reduced Tafel slope of 57 mV·dec
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to meet the maximum current density of 250 mA·cm
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catalyst resulted in a porous structure with accessible active sites, which enabled adsorption of the intermediates and afforded an effective charge transfer rate for promoting the oxygen evolution reaction. Furthermore, the combined effect of the catalyst components provided long-term stability for over 110 h in an alkaline solution, which makes the catalyst promising for large-scale practical applications. The aforementioned advantages of the composite catalyst overcome the limitations of low conductivity, agglomeration, and poor stability of the pure catalysts (Cu
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Se and V
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In current state of the World, the pollution is increasing very fast. One of its major reason is the production of huge quantity of cement which causes outflow of CO2 into the environment and land ...dumping of construction and demolition waste which leads to the land pollution. In order to address this major issue, it is important to decrease the utilization of cement by substituting the cement with by product such as slag and using recycled aggregates as a replacement of natural aggregates. This research aimed to utilize evaluate the performance of sustainable high-performance concrete reinforced with steel fibers which is produced with recycled aggregate. Crushed stone aggregates are supplanted with recycled aggregates extracted from source concrete that had compression strength of 45 MPa and 85 MPa at proportions of 50% and 100%. Steel fibers are used at 2% to produce high-performance concrete, and in a few of the mixtures, the cement was substituted with granulated blast furnace slag. In addition to mechanical performance, the durability properties, i.e., electrical resistivity, drying shrinkage, and water absorption, of concrete blends were examined. The test outcomes show that high-performance concrete with the required characteristics can be developed utilizing recycled aggregates extracted from source concrete of high strength. The inclusion of double hooked end steel fibers considerably improves the mechanical characteristics of RAC. Concrete formed with high-quality recycled concrete aggregates and mixes comprising granulated blast furnace slag (GBFS) and double hooked end (DHE) steel fibers shows decreased drying shrinkage and water absorption in comparison to normal concrete. The outcomes of the present study assist in making of suitable high-performance concrete which is sustainable and budget friendly.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A hybrid strengthening system, comprising a carbon fiber reinforced polymer (CFRP) sheet combined with fiber reinforced concrete (FRC) layer is proposed in this study as a mitigatory solution to ...brittle debonding problems. Five reinforced concrete (RC) beams, comprising both control cases and those strengthened with the hybrid CFRP-FRC system at various FRP reinforcement ratios, were fabricated and tested to assess the system's effectiveness. A comprehensive finite element (FE) model was also developed to complement the experimental campaign and extend it into a parametric investigation on the effects of FRP reinforcement ratio (ρf), fiber percentage in FRC (vf), and FRC layer thickness (tFRC). Compared with beams strengthened with FRP alone, using the FRC layer increased the ultimate load (Pult.) of FRP-strengthened beams by 29–59%, depending on ρf and vf. The ductility of the hybrid FRP-FRC strengthened beams also increased by more than twice compared to the beams strengthened with only FRP. For the FRP reinforcement ratio (ρf) of 0.18%, use of an FRC layer with vf = 2% yields the highest increase in Pult. and ductility for the hybrid system. Ultimately, the brittle FRP debonding failure was successfully eliminated using the FRC layer, leading to desirable FRP rupture. Built with capabilities to capture material nonlinearity, contact, and debonding phenomena, the FE model predictions excellently matched those of the test results in terms of the beam’s capacity, failure modes as well as load-deflection and load-strain responses.
•A hybrid strengthening using CFRP sheets combined with FRC layer is proposed.•Performance was evaluated using tests on RC beams at various FRP reinforcement ratios.•A comprehensive finite element model was developed to complement the experiment.•FRC layer serves as a mitigatory solution to brittle FRP debonding and leads to desirable FRP rupture.•Compared with FRP only strengthening, FRC layer increased the capacity by 29–59% along with up to twice the ductility realized by using FRP alone.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, solution is obtained for the free vibration differential equations of motion of an axially loaded beam on elastic foundation using a meshless method. Use is made of the multiquadrics ...radial basis function (RBF) in obtaining the numerical solution for four different cases: (1) one end clamped, the other end simply supported; (2) both ends clamped; (3) both ends simply supported; and (4) a simple beam on elastic foundation with end rotational springs. The approach is easier to implement and program as compared to grid/mesh-based methods such as the finite difference method (FDM) and the finite element method (FEM). Accuracy of the results obtained using the proposed method was verified using the analytical results available in the literature for the first three cases considered. Numerical results of the fourth case were aimed at justifying the use of the numerical scheme for a problem whose analytical solution is not readily available and to show the high accuracy of the RBF method. The results prove that the method require much less number of nodes to converge to the correct solution as compared to FDM.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Laminated composite plates have become a crucial point of interest in the industry, with the need to ensure sustained and stable structures throughout the plates’ lifespan. This study conducted a ...bibliometric analysis using the Scopus database, gathering 8221 documents for further scrutiny based on the linked meta-data. Utilizing the VOS viewer software version 1.6.19, maps were generated from scientific publishing network data, illustrating connections between researchers’ nations and keywords. The investigation into co-occurring phrases associated with laminated composite plates employed author keywords. The results reveal a significant and close relationship among top authors, suggesting a strong research connection, with the United States and China leading the field. Top cited documents and keyword correlations are examined to gauge current research interests. These critical reviews serve as essential resources for scholars and practitioners in the field. Additionally, the review discusses the advancements in and practical applications of different theories for laminated composite plates, with a focus on a bibliometric study using the Scopus database. This paper categorizes models within the context of an equivalent single-layer laminate, analyzing variations in established theories and methodologies for modeling laminated composite plates to offer a nuanced understanding of approaches and assessments in this field.
•Experimental bond testing of NSM FRP in low- and normal-strength concrete is conducted.•Use of natural and recycled aggregates in low-strength concretes is investigated.•NSM FRP-concrete bond ...strength decreases with an increase in RCA in low-strength concretes.•Steel fiber used in some of the mixes marginally increased the bond failure capacity.•FE model was used to verify effect of key bond parameters in both low and high-strength concretes.•Parametric studies were conducted using the bar diameter, concrete compressive strength, FRP modulus, and steel fiber content as variables.
Poor mechanical properties of construction materials constitute one of the major reasons for structural deterioration. Since the extent of the weakening in the material quality could reach an alarming threshold, their suitability for strengthening needs assessment prior to adopting any strengthening strategy. This paper experimentally investigates the bond behavior between near-surface mounted (NSM) fiber-reinforced polymer (FRP) strengthening in low- and normal-strength concrete with compressive strength in the range of 11.6 – 14.8 MPa for the former and 39.4 MPa for the latter. The use of two aggregate types – natural and recycled aggregates – was also investigated in the low-strength concretes. Steel fiber reinforcement was used in some of the mixes to check whether some enhancement is possible in low-quality concrete that can result from inferior recycled material, compromised workmanship, or material deterioration due to durability challenges. Ultimately, the variables of the study include recycled coarse aggregate incorporation ratio of 0%, 30%, 60%, and 100% replacement of the natural aggregate for each of the steel fiber’s percentages of 0%, 0.5%, and 1% of the specimen’s volume. The control NSM FRP-concrete specimen made from normal-strength concrete (39.4 MPa) was prepared and tested as a reference. The low-strength concrete mixtures demonstrated a decrease in the NSM FRP-concrete bond strength with an increase in the RCA incorporation. However, the addition of steel fibers marginally increased the bond failure capacity. Compared to the reference specimen of normal-strength concrete, at least, a 44% reduction in the NSM-concrete bond failure load was observed. Because some design guides (including the ACI 440) suggest a minimum concrete compressive strength for NSM FRP strengthening, a finite element model (FEM) was used to check the full spectrum of the mixture’s quality (both low and high-strength materials) and other key parameters affecting the NSM FRP-concrete bond behavior. The so-developed model is first validated against the experimental observations, followed by using it to run a series of parametric studies using the bar diameter, concrete compressive strength, FRP modulus, and steel fiber content as variables.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pain is a multifaceted, multisystem disorder that adversely affects neuro-psychological processes. This study compares the effectiveness of central stimulation (transcranial direct current ...stimulation—tDCS over F3/F4) and peripheral stimulation (transcutaneous electrical nerve stimulation—TENS over the median nerve) in pain inhibition during a cognitive task in healthy volunteers and to observe potential neuro-cognitive improvements. Eighty healthy participants underwent a comprehensive experimental protocol, including cognitive assessments, the Cold Pressor Test (CPT) for pain induction, and tDCS/TENS administration. EEG recordings were conducted pre- and post-intervention across all conditions. The protocol for this study was categorized into four groups: G1 (control), G2 (TENS), G3 (anodal-tDCS), and G4 (cathodal-tDCS). Paired t-tests (p < 0.05) were conducted to compare Pre-Stage, Post-Stage, and neuromodulation conditions, with t-values providing insights into effect magnitudes. The result showed a reduction in pain intensity with TENS (p = 0.002, t-value = −5.34) and cathodal-tDCS (p = 0.023, t-value = −5.08) and increased pain tolerance with TENS (p = 0.009, t-value = 4.98) and cathodal-tDCS (p = 0.001, t-value = 5.78). Anodal-tDCS (p = 0.041, t-value = 4.86) improved cognitive performance. The EEG analysis revealed distinct neural oscillatory patterns across the groups. Specifically, G2 and G4 showed delta-power reductions, while G3 observed an increase. Moreover, G2 exhibited increased theta-power in the occipital region during CPT and Post-Stages. In the alpha-band, G2, G3, and G4 had reductions Post-Stage, while G1 and G3 increased. Additionally, beta-power increased in the frontal region for G2 and G3, contrasting with a reduction in G4. Furthermore, gamma-power globally increased during CPT1, with G1, G2, and G3 showing reductions Post-Stage, while G4 displayed a global decrease. The findings confirm the efficacy of TENS and tDCS as possible non-drug therapeutic alternatives for cognition with alleviation from pain.
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