bluuebunny/crossref_metadata_2025 huggingface dataset:
Cálculo da mínima diferença clínica importante dos escores Lysholm e IKDC após reconstrução do ligamento cruzado anterior
Authors: Nascimento Bruno Fajardo do , Lima Mariana Bandeira da Rocha , Dias Júnior Jair Moreira , Antunes Filho Jurandir , Campos Túlio Vinícius de Oliveira , Mendes Júnior Adriano Fernando
Published: October 2022

Objetivo Calcular o valor da mínima diferença clinicamente importante (MDCI) para os escores de Lysholm e International Knee Documentation Commitee (IKDC) na amostra de pacientes submetidos a reconstrução de ligamento cruzado anterior.

Métodos Estudo primário, observacional, retrospectivo, analítico, de participantes submetidos a reconstrução do ligamento cruzado anterior no período de março de 2019 a dezembro de 2020, pelo mesmo cirurgião, com seguimento mínimo de 6 meses, análise da função do joelho no período pré e pós-operatório pelos escores de Lysholm e IKDC, e resposta a uma pergunta âncora aos 6 meses de seguimento pós-operatório, para o MDCI de cada escore.

Resultados Participaram do estudo 59 pacientes, com média de idade de 27,1 ± 5,7 anos. Na comparação dos escores pré- e pós-operatórios de todos os grupos, observa-se aumento dos valores com significância estatística após a intervenção. A MDCI foi de 5,5 para o escore de Lysholm, não tendo sido possível determinar o valor para o IKDC.

Conclusão O cálculo do valor da MDCI pelo método da pergunta âncora, na amostra avaliada, foi de 5,5 para o escore de Lysholm. Não foi possível determinar o valor da MDCI para o IKDC.
Arthroscopic Assistance in Surgical Management of Distal Radius Fractures: A Systematic Review and Meta-analysis
Authors: Román-Veas Javier , Gutiérrez-Espinoza Héctor , Campos-Jara Christian , Martínez-García Darío
Published: October 2022

Background Wrist arthroscopy has become a commonly used tool for the management of adults with distal radius fractures (DRFs), although its implementation requires technical competence. This systematic review and meta-analysis appraised the available evidence concerning the contribution of wrist arthroscopy to the functional and radiological outcomes of patients with DRFs operated with arthroscopic assistance.

Methods Randomized control trials were identified through five principal electronic databases on May 31, 2022: Web of Science, Scopus, EBSCO, Embase, and PubMed. Two authors independently performed the search and data extraction and assessed risk of bias (RoB) using the Cochrane RoB tool.

Results A total of 1,780 relevant abstracts and citations were extracted in the preliminary search, which yielded 6 trials that met the eligibility criteria, and 3 studies were included in the quantitative synthesis. The overall pooled mean difference (MD) estimate showed no significant difference in the Disabilities of the Arm, Shoulder, and Hand scores between surgical groups with and without arthroscopic assistance (MD = 0.77 points, 95% confidence interval = −6.58 to 5.03, p = 0.79), with substantial heterogeneity (I2 = 85%).

Conclusion There was low-quality evidence that wrist arthroscopy conveyed not clinically or statistically significant difference to functional outcomes of patients with DRFs. However, our findings are limited by the numbers of studies included and lack of long-term follow-up, although they do provide a good starting point for future quality research.
Heat transfer in granular media with weakly interacting particles
Authors: Persson B. N. J. , Biele J.
Published: October 2022

We study the heat transfer in weakly interacting particle systems in vacuum. The particles have surface roughness with self-affine fractal properties, as expected for mineral particles produced by fracture, e.g., by crunching brittle materials in a mortar, or from thermal fatigue or the impact of micrometeorites on asteroids. We show that the propagating electromagnetic (EM) waves give the dominant heat transfer for large particles, while for small particles both the evanescent EM-waves and the phononic contribution from the area of real contact are important. As an application, we discuss the heat transfer in rubble pile asteroids.
Vibronic coupling in the ground and excited states of the imidazole radical cation
Authors: Trofimov A. B. , Skitnevskaya A. D. , Grigoricheva E. K. , Gromov E. V. , Köppel H.
Published: October 2022

Vibronic interactions in the ground and two excited states of the imidazole radical cation, X2A″ (π−1), A2A′ (nσ−1), and B2A″ (π−1), and the associated nuclear dynamics were studied theoretically. The results were used to interpret the recent photoelectron measurements [M. Patanen et al., J. Chem. Phys. 155, 054304 (2021)]. The present high-level electronic structure calculations employing, in particular, the single, double, and triple excitations and equation-of-motion coupled-cluster method accounting for single and double excitation approaches and complete basis set extrapolation technique for the evaluation of the vertical ionization energies of imidazole indicate that the A 2A′ and B 2A″ states are very close in energy and subject to non-adiabatic effects. Our modeling confirms the existence of pronounced vibronic coupling of the A 2A′ and B 2A″ states. Moreover, despite the large energy gap of nearly 1.3 eV, the ground state X 2A″ is efficiently coupled to the A 2A′ state. The modeling was performed within the framework of the three-state linear vibronic coupling problem employing Hamiltonians expressed in a basis of diabatic electronic states and parameters derived from ab initio calculations. The ionization spectrum was computed using the multi-configuration time-dependent Hartree method. The calculated spectrum is in good agreement with the experimental data, allowing for some interpretation of the observed features to be proposed.
Influence of the coordination defects on the dynamics and the potential energy landscape of two-dimensional silica
Authors: Roy Projesh Kumar , Heuer Andreas
Published: October 2022

The main cause of the fragile-to-strong crossover of 3D silica was previously attributed to the presence of a low-energy cutoff in the potential energy landscape. An important question emerges about the microscopic origin of this crossover and its generalizibility to other glass-formers. In this work, the fragile-to-strong crossover of a model two-dimensional (2D) glassy system is analyzed via molecular dynamics simulation, which represents 2D-silica. By separating the sampled defect and defect-free inherent structures, we are able to identify their respective density of state distributions with respect to energy. A low energy cutoff is found in both distributions. It is shown that the fragile-to-strong crossover can be quantitatively related to the parameters of the energy landscape, involving, in particular, the low-energy cutoff of the energy distribution. It is also shown that the low-energy cutoff of the defect-states is determined by the formation energy of a specific defect configuration, involving two silicon and no oxygen defects. The low-temperature behavior of 2D silica is quantitatively compared with that of 3D silica, showing surprisingly similar behavior.
A transient hydrodynamic model of screen channel liquid acquisition devices for in-space cryogenic propellant management
Authors: Camarotti C. F. , Hartwig J. W. , Wang H. , Chung J. N.
Published: October 2022

Screen channel liquid acquisition devices (LADs) will play a crucial role in future deep space travel. It is essential that vapor-free delivery of propellants during tank-to-tank transfer is ensured to maximize yield from storage tanks and prevent potential combustion instabilities. The screen channel LAD utilizes a fine screen wire mesh that can separate phases in a low Bond number (i.e., microgravity) environment using surface tension forces. This study presents the development and verification of a new model for transient screen compliance, one of the influential factors for screen channel LAD design. Screen compliance is crucial during LAD channel outflow transients because the slight deflection of the screen can provide needed mass to satisfy rapid outflow demands and reduce the pressure difference across the screen. The model is successfully verified against computational fluid dynamics simulations. In addition, the characteristic speed for the governing screen compliance equations is derived, which allows for numerical stability criteria to be established. As shown in this study, the transient maximum pressure difference across the screen can greatly exceed the steady state maximum pressure difference across the screen in many cases.
Estimating forces from cross-sectional data in the wake of flows past a plate using theoretical and data-driven models
Authors: Tong Wenwen , Wang Shizhao , Yang Yue
Published: October 2022

We report a comparative study of theoretical and data-driven models for estimating forces from velocity data in the wake of three-dimensional flows past a plate. The datasets with a range of angles of attack are calculated using the immersed boundary method. First, we develop a theoretical model to estimate forces on a flat plate from cross-sectional velocity data in the far wake. This algebraic model incorporates the local momentum deficit and pressure variation. Second, we develop several data-driven models based on the convolutional neural network (CNN) for force estimation by regarding the velocity field on a series of cross sections as images. In particular, we design three CNN architectures for integrating physical information or attention mechanism, and use different training datasets for interpolation and extrapolation tasks. The model performances indicate that the optimized CNN can identify important flow regions and learn empirical physical laws. The theoretical and CNN models are assessed by multiple criteria. In general, both models are accurate (with errors less than 10%), robust, and applicable to complex wake flows. The theoretical model is superior to the CNN model in terms of the completeness, cost, and interpretability, and the CNN model with the appropriate training data and optimized CNN architecture has better description and accuracy.
A blast fungus zinc-finger fold effector binds to a hydrophobic pocket in host Exo70 proteins to modulate immune recognition in rice
Authors: De la Concepcion Juan Carlos , Fujisaki Koki , Bentham Adam R. , Cruz Mireles Neftaly , Sanchez de Medina Hernandez Victor , Shimizu Motoki , Lawson David M. , Kamoun Sophien , Terauchi Ryohei , Banfield Mark J.
Published: October 2022

Exocytosis plays an important role in plant–microbe interactions, in both pathogenesis and symbiosis. Exo70 proteins are integral components of the exocyst, an octameric complex that mediates tethering of vesicles to membranes in eukaryotes. Although plant Exo70s are known to be targeted by pathogen effectors, the underpinning molecular mechanisms and the impact of this interaction on infection are poorly understood. Here, we show the molecular basis of the association between the effector AVR-Pii of the blast fungusMaganaporthe oryzaeand rice Exo70 alleles OsExo70F2 and OsExo70F3, which is sensed by the immune receptor pair Pii via an integrated RIN4/NOI domain. The crystal structure of AVR-Pii in complex with OsExo70F2 reveals that the effector binds to a conserved hydrophobic pocket in Exo70, defining an effector/target binding interface. Structure-guided and random mutagenesis validates the importance of AVR-Pii residues at the Exo70 binding interface to sustain protein association and disease resistance in rice when challenged with fungal strains expressing effector mutants. Furthermore, the structure of AVR-Pii defines a zinc-finger effector fold (ZiF) distinct from the MAX (Magnaporthe Avrs and ToxB-like) fold previously described for a majority of characterizedM.oryzaeeffectors. Our data suggest that blast fungus ZiF effectors bind a conserved Exo70 interface to manipulate plant exocytosis and that these effectors are also baited by plant immune receptors, pointing to new opportunities for engineering disease resistance.
Politeness reciprocity in Shakespeare’s dialogue
Authors: Culpeper Jonathan , Oliver Samuel J. , Tantucci Vittorio
Published: October 2022

Recently, it has been proposed that (im)politeness in interaction today is governed in large part by a Principle of (Im)politeness Reciprocity (Culpeper and Tantucci 2021). This paper investigates whether politeness reciprocity works similarly in early modern English – specifically, in the plays of Shakespeare. Focussing on thanking behaviours, the questions of whether politeness reciprocity can be detected, and, if so, how social status might influence the nature of reciprocity, are addressed. The first part of the paper establishes that Early Modern English politeness behaviours were being discussed in terms associated with reciprocity (e.g., metaphors relating to balance and financial/commercial transactions). Then, all the instances of the two main thanking formula patterns (the verbalfirst person pronoun+thanks+second person pronounand the nominalthanks) were extracted from thirty-eight plays attributed wholly or substantially to Shakespeare, and coded for a number of variables, including the weightiness of the gift for which thanks has been given, the amount of effort expended in performing thanks, and the social statuses of the Thanker and Thankee. The results show that reciprocity does govern thanking behaviours, and that social status licences imbalances in those behaviours. The paper also touches on conventionalisation.
Translanguaging in CLIL
Authors: Lisaitė Donata , Smits Tom F. H.
Published: October 2022

Translanguaging was a relatively little-known concept 20 years ago, but has now become a ‘household name’ in
academic contexts. The body of research on translanguaging is ever-growing and the concept covers a vast field from bilinguals’
everyday language use to a theory of language and education. By means of a scoping literature review this study focuses on
translanguaging as a pedagogy within bilingual education and synthesises existing empirical research on the topic that was carried
out between 1990 and 2020.
Dynamic Behavior of Optical Soliton Interactions in Optical Communication Systems
Authors: Wang Shubin , Ma Guoli , Zhang Xin , Zhu Daiyin
Published: October 2022

In optical systems, it is necessary to investigate the propagation of optical solitons in optical fiber systems for fiber-optic communications. By means of the bilinear method, we obtain the two-soliton solution of the variable coefficient higher-order coupled nonlinear Schrödinger equation. According to the obtained two-soliton solution, a novel two-soliton interaction structure of the system is constructed, and their interactions are studied. Two optical solitons occur with elastic interaction under certain conditions, and their amplitudes, shapes and velocities remain unchanged before and after the action. In addition to the elastic interaction, splitting action and polymerization also occur. The present study on the dynamic behavior of interaction of optical solitons may be valuable for research and applications in optical communication and other fields.
Generalized Mathisson–Papapetrou–Tulczyjew–Dixon equations
Authors: Ootsuka Takayoshi , Yahagi Ryoko
Published: October 2022

We derive two generalizations of Mathisson–Papapetrou–Tulczyjew–Dixon equations from Casalbuoni–Brink–Schwarz type pseudoclassical Lagrangians of Majorana spinors on a Riemann–Cartan spacetime. One has an additional gauge freedom, which makes the equations of motion also be a generalization of Wong’s equations. The other is a spinor model coupled with a Rarita–Schwinger field to preserve the supersymmetry. The coupling to the torsion is modified due to the existence of the Rarita–Schwinger field. In both extensions, the Tulczyjew condition is automatically satisfied.
An unsupervised convolutional neural network method for estimation of intravoxel incoherent motion parameters
Authors: Huang Hsuan-Ming
Published: October 2022

Objective. Intravoxel incoherent motion (IVIM) imaging obtained by fitting a biexponential model to multiple b-value diffusion-weighted magnetic resonance imaging (DW-MRI) has been shown to be a promising tool for different clinical applications. Recently, several deep neural network (DNN) methods were proposed to generate IVIM imaging. Approach. In this study, we proposed an unsupervised convolutional neural network (CNN) method for estimation of IVIM parameters. We used both simulated and real abdominal DW-MRI data to evaluate the performance of the proposed CNN-based method, and compared the results with those obtained from a non-linear least-squares fit (TRR, trust-region reflective algorithm) and a feed-forward backward-propagation DNN-based method. Main results. The simulation results showed that both the DNN- and CNN-based methods had lower coefficients of variation than the TRR method, but the CNN-based method provided more accurate parameter estimates. The results obtained from real DW-MRI data showed that the TRR method produced many biased IVIM parameter estimates that hit the upper and lower parameter bounds. In contrast, both the DNN- and CNN-based methods yielded less biased IVIM parameter estimates. Overall, the perfusion fraction and diffusion coefficient obtained from the DNN- and CNN-based methods were close to literature values. However, compared with the CNN-based method, both the TRR and DNN-based methods tended to yield increased pseudodiffusion coefficients (55%–180%). Significance. Our preliminary results suggest that it is feasible to estimate IVIM parameters using CNN.
Generation and decay of N2(A3Σu
+) molecules in reacting CO2 and CH4 plasmas
Authors: Mignogna David , Jans Elijah R , Raskar Sai , Adamovich Igor V
Published: October 2022

Time-resolved number densities of N2(A3Σu
+, v = 0, 1) molecules in diffuse ns pulse discharge plasmas in N2, N2–H2, N2–CH4, N2–CO2, and N2–CO2–CH4 are measured by tunable diode laser absorption spectroscopy (TDLAS). The first series of measurements is made in the discharge pulse bursts at a relatively low pulse repetition rate (3 kHz), when the N2(A3Σu
+) generation and decay after individual discharge pulses is fully resolved. The second set of data is taken during a sequence of two pulse bursts generated at a higher pulse repetition rate (100 kHz), for different delay times between the first and second bursts. This approach is used to determine the effect of accumulation and decay of reacting species generated in the plasma, including N, H, and O atoms, CO molecules, and C2 hydrocarbon product species, on the rate of N2(A3Σu
+) production and quenching. The effect of these species can be isolated since the rates of N2(A3Σu
+) quenching by the initial reactant species (H2, CH4, and CO2) are slow. Comparison of the measurement results with the kinetic modeling predictions is used to obtain insight into the plasma chemical reaction kinetics. The results complement the measurements of N, H, O, and CO in high-pressure reacting plasmas, and help quantify the plasma chemical processes driven by the electron impact dissociation, electronic excitation, and reactive quenching of the excited electronic states. The present results may be used for the development and validation of higher fidelity kinetic models of reacting plasmas, incorporating state-specific electronic and vibrational energy transfer and chemical reactions.
Development and experimental characterization of a large-capacity magnetorheological damper with annular-radial gap
Authors: Abdalaziz Moustafa , Vatandoost Hossein , Sedaghati Ramin , Rakheja Subhash
Published: October 2022

Magnetorheological (MR) dampers with bypass arrangements and combined annular-radial fluid flow channels have shown superior performance compared to conventional MR dampers with single annular/radial fluid flow gaps. Achieving a higher controllable dynamic force range with low off-state but high on-state damping force is yet a significant challenge for developing MR dampers for high payload ground vehicle suspensions. This paper presents the conceptual design, fabrication, and experimental characterization of a mid-sized large-capacity MR damper equipped with a compact annular-radial MR fluid bypass valve. Extensive experimental tests were conducted to investigate the dynamic characteristics of the proposed MR damper considering wide ranges of excitation frequency, loading amplitude, and electrical current. The equivalent viscous damping and the dynamic range were calculated as functions of loading conditions considered. The proposed damper initially realized the maximum dynamic range and damping force of 2.3 and 5.54 kN, respectively. With MR valve design modifications, the maximum dynamic range and damping force were substantially increased, reaching 5.06 and 6.61 kN, respectively. The effectiveness of the proposed MR damper was subsequently identified by comparing its dynamic range with other conventional MR dampers in previous studies. The results confirmed the superior performance of the proposed MR damper and its potential application for highly adaptive suspension systems for off-road wheeled and tracked vehicles.
Orbital angular momentum for turbulence mitigation in long free-space optical communication links
Authors: Secilmis Gamze Nur , Elmabruk Kholoud
Published: October 2022

The ability of laser beams carrying orbital angular momentum to reduce the scintillation level of Gaussian beam propagating in atmospheric turbulence is numerically investigated. The effect of topological charge, beam waist, operating wavelength and also the receiver radius on the scintillation indices is examined in detail. It is shown that the Gaussian beam carrying orbital angular momentum has a priority over a fundamental Gaussian beam in communication links longer than 2.5 Km. It is clear that Gaussian beams carrying orbital angular momentum in the cases when having a small beam waist and operating at a high wavelength are able seriously to reduce the scintillation index. Accordingly, the presented results will be significant for designing optical communication links that use laser beams carrying orbital angular momentum.
3C-SiC/Si heterostructure for self-powered multiband (UV-VIS) photodetection applications
Authors: Tamay Ilayda M , Teker Kasif
Published: October 2022

This study reports a self-powered 3C-SiC/Si heterostructure photodetector in both metal-semiconductor-metal (MSM) and heterojunction (HET) configurations and capable of operating under ultraviolet and visible light (UV–vis). The single crystalline 3C-SiC thin film was grown epitaxially on a Si (111) substrate by employing a two-step growth process. MSM configuration exhibited a peak responsivity of 0.334 A W−1 and a specific detectivity of 5.4 × 1011 cm.Hz1/2.W−1 (Jones) under white light illumination. However, in the UV region, photocurrent showed an increasing behavior with a decrease in the UV wavelength from 365 nm to 254 nm. The peak responsivity and specific detectivity values of the HET configuration were also determined under white light illumination with 0.167 A W−1 and 4.4 × 1011 Jones, respectively. Furthermore, both devices exhibited very fast rise and decay times as 3.8 ms and 3.6 ms for the MSM, and 6 ms and 8 ms for the HET configuration (fastest reported on 3C-SiC). In brief, our self-powered 3C-SiC/Si heterostructure with multiband (UV–vis) photodetection sensitivity and fast speed could offer new solutions for the eco-friendly and sustainable optoelectronic applications.
Unraveling the dual emission of single quantum-dot by single particle spectroscopy
Authors: Layek Arunasish , Arora Vikas , Sapra Sameer , Chowdhury Arindam
Published: October 2022

Two-color emissive 0D–2D quantum-dot quantum-well (QD-QW) heteronanocrystals has created profound research activities. First multicolor emission in the visible region has been reported by Peng and co-workers in CdSe(core)–ZnS(barrier)-CdSe(shell) (core-barrier-shell) based heteronanostructures where the both CdSe phases (core and the shell) are emissive and tuneable as well. Owing to this enhanced and tuneable functionality, the QD-QW systems colloidal nanocrystals has fuelled their optical and imaging applications. Single particle spectroscopy has taken a giant step toward unravelling the features of individual particles and thus to provide direct information on their heterogeneity. To elucidate the dual emission characteristic of individual nanocrystals we performed energy mapped photoluminescence imaging. Surprisingly, the pseudo color PL intensity image shows that not all single particles are dual emissive in nature, few are either green emitting or red emitting. Photoluminescence spectrum of individual nanocrystals further confirms that individual nanocrystals can be dual emissive in nature. However, single color emissive dots are also present indicating the ensemble heterogeneity at single particle levels. The temporal evolution PL spectra of a single quantum shows spectral diffusion. The single dot experiments on the dual emissive QD-QW system unravels hidden photophysics which are otherwise not observed by ensemble spectroscopy.
Application of material budget imaging for the design of the ATLAS ITk strip detector
Authors: Arling J.-H. , Gregor I.-M.
Published: October 2022

The technique of material budget imaging (MBI) allows to experimentally assess the material budget ϵ = x/X
0 of a material with thickness x and its radiation length X
0. Here, multi-GeV electrons from a test beam facility such as the DESY-II test beam are used. This novel technique exploits the fact that the beam particles are deflected by multiple Coulomb scattering following a distribution of the deflection angle with a center at zero and a width depending on the traversed material. By reconstructing the individual kink angles from the measured particle trajectories in a high resolution beam telescope, the material budget can be extracted by applying appropriate models of multiple scattering theory, such as the Highland formula.

On the one hand, various materials with known material budgets were measured to calibrate the MBI technique and study also different systematic effects such as the beam telescope’s acceptance and the variation of the beam energy. On the other hand, a number of material samples planned in the design of the local support structures of the new ATLAS Inner Tracker (ITk) strip detector were investigated to extract the according radiation length values not known beforehand.

This paper shows therefore the potential of the MBI technique to give an input for the design of high-energy particle detectors by providing experimentally measured numbers of the radiation length for various material compounds with not a-priori known X
0 values.
Critical Evaluation of Reinforced Concrete Beams Using Digital Image Correlation Technique
Authors: Masthan Reddy V.V. , Vidhyalakshmi S.
Published: October 2022

Digital Image Correlation technique (DIC) is a non-contact optical method for rapid structural health monitoring of critical infrastructure. DIC is used to extract Moment (M) – Curvature (κ) relationships using random speckle patterns. The random speckle pattern is evaluated for 2D DIC measurements and shows an improved correlation with conventional measurements. Characteristics of random speckle patterns are quantified and their applicability to DIC is explored. The ultimate moment-curvature values computed from the random speckled pattern are found to be in good agreement with conventional measurements.
Comparison of Seismic Analysis of Multi storey Buildings with RCC columns and CFST columns by Varying Heights
Authors: Swarna Chadalavada , Reddy Suda V B
Published: October 2022

As there is an increase in population day by day, there is more requirement for land. But the availability of land on Earth’s surface is 29 % which should be used for various purposes and hence, there would be difficulty in providing accommodation to all the citizens. There comes the idea of vertical development of the structures i.e., multi-story structures. Usage of Reinforced Cement Concrete (RCC) for high rise structures with large spans would be very complex as it requires high grade concrete and steel and hence becomes risky. In that case, the composite structures give effective results due to the co-action of materials. Providing Concrete Filled Steel Tube (CFST) columns will reduce the requirement of formwork and will increase the functional area as the steel tube acts both as longitudinal as well as transverse reinforcement which gives mere resistance to tensile stresses. In this thesis, Multi Storied Structures of G+10, G + 20 and G + 30 were taken and variation was considered in the columns, the rest of the structural elements have been taken of RCC only. The seismic analysis of the structures has been carried out for both the type of structures for each height by using Response Spectrum analysis in Zone II following the guidelines of IS 1893:2016 code using ETABS software. The comparison of the structures has been shown in terms of earthquake response parameters such as story drift, story displacement, story shear etc. It has been concluded that structures with CFST columns have shown better seismic performance with increasing height compared to RCC structures.
A Study on Partial Replacement of Cement by Aluminium Powder in Polypropylene Fiber Reinforced Concrete
Authors: Reddy Sripathi Sai Jagan Mohan , Mallikarjuna Rao G , Oggu Praveen
Published: October 2022

The fibers are well described by a combination of stiffness, strength, and temperature resistance. A lightweight polymer material with great strength, resistance to corrosion, and crack arresting properties is polypropylene fiber. The structure is lighter than ordinary concrete because of the reaction between the aluminium powder and the calcium hydroxide in the cement matrix, which results in the production of hydrogen gas. It is used to make concrete more durable and strong. Due to its reduced particle size distribution, they scatter among and separate the cement particles, changing the cement paste’s structure such that it contains more C-S-H and less Ca(OH)2. In this study, final mix proportions to attain M30 & M60 grades are computed and effects of adding polypropylene fibers varying from 0.5 to 2.0 percent are studied. 1.5 percent gave the better results dependent on mechanical properties of the concrete. A variable percent of aluminium powder is then substituted for the fiber optimization percent (1.5 percent) dependent on mechanical properties of the concrete. Slump test, compressive, split tensile, and flexural strength tests are used to evaluate the quality and 1.0 percent gave the better results dependent on the tests. The mixture that develops a practical, cost-effective, and strength criteria is sorted out and examined for durability by conducting sorptivity and acid attack tests. It is concluded that the addition of polypropylene fibers improved the strength of concrete relatively and the addition of aluminium powder improved the durability of the concrete.
Study on Compressive Strength of Reinforced and Cavity Wall Brickwork
Authors: Thenmozhi R , Saranya K
Published: October 2022

The research of the mechanical behaviour of reinforced and cavity wall brickwork is the focus of this paper. In this paper, the casting of specimens are done manually and totally 18 specimens are prepared. The different proportions were followed for casting the bricks and specimens. The bricks used are red bricks, fly ash bricks and solid bricks. Conventional method of casting is done using mortar and casting of reinforced brick prism is done with red bricks, fly ash bricks and solid bricks. The cavity wall is constructed and finally the compressive strength is estimated for the reinforced and cavity wall brickworks. The obtained compressive strength for various bricks is plotted in the form of graph to interpret the exact results and comparison is drawn for all types of bricks used.
Optimising partial replacement of coarse and fine aggregates with medical PP plastic and HIPS plastic waste to develop lightweight concrete
Authors: Khaudiyal S , Gour M A , Garg N , Das S K , Kumar S
Published: October 2022

Climate change, land scarcity, overexploitation of natural resources, generation of vast amount of trash, and the difficulty to dispose off that trash in an effective and safe manner are just some of the issues that modern society is now dealing with. Inevitably, as the need for new construction rises, so does the demand for the materials needed to make new buildings. Incorporating waste components into the concrete will alleviate some of the pressure placed on the virgin building materials and will also contribute to the removal of a sizeable amount of garbage from the surface of the earth. This study has been undertaken to highlight and showcase the utilization of plastic wastes as an aggregate replacement. The study aims to develop a lightweight concrete using plastic wastes. Here, natural coarse aggregates have been replaced by black polypropylene (PP) plastic and natural fine aggregates are replaced with high-strength polystyrene commonly known as HIPS plastic. The literature suggested an optimum replacement percentage of 40% against natural coarse. For a constant workability, a combination of 40% coarse replacement along with 10% fine aggregate replacement was found to be optimum with comparable mechanical properties as compared to conventional concrete. With the inclusion of plastic aggregates into the concrete, a significant weight reduction was observed. When 40% coarse aggregate and 10% fine aggregates were replacement with PP plastic and HIPS plastic, respectively, a weight reduction of 21.17% was observed.
An Experimental Study on Coir Fiber Reinforced Concrete with Ground Granulated Blast Furnace Slag and Dolomite Powder as Partial Replacement of cement
Authors: Prafulla K , Nagaraju Avari
Published: October 2022

Incorporation of fibers definitely advantages blended concrete to take care of micro structural cracks and improving the early strength of concrete. However, fibers made from industrial by-products (synthetic) had some disadvantages like cost, causing health disorders and increasing the density of the concrete. In contrast to synthetic fibers, natural fibers may address the above mentioned problems without compromising the strength. In recent times, more research is emphasizing on sustainable concrete, replacing the conventional materials with industrial by-product. In this connection, cement is giving lot of environmental problems. Hence, Researchers has investigating alternate materials as secondary supplementary cementitious materials. In this present research work, behavior of ternary blended coir fiber reinforced concrete (M40 grade) was studied. In this study, Ground Granulated Blast furnace slag (GGBS) replaced the cement by 10%, 20% and 30% of the weight of cement. Along with this, Dolomite power also replaced the cement by 10%, 20%, 30% of the weight of cement. Further, coir fiber of percentages 0%, 0.5%, 1%, 1.5% of weight of concrete, was added to concrete. Mechanical properties were determined after 7 and 28 days of curing. The strength of concrete was increased by addition of fibers up to 0.5% of weight of concrete. The optimum percentage was achieved at 20% of GGBS and 10% of Dolomite Powder.
Experimental investigation on tobacco waste ash for sustainable development
Authors: Rao Nerusu Venkata Srinivasa , Babu Padavala Siva Shanmukha Anjaneya , Sai Krishna G , Loya Ganesh Babu
Published: October 2022

The enormous use of cement in construction leads to an effect on the environment. For 1 ton of cement production, nearly 1 ton of CO2 is released into the atmosphere. The production of Portland cement reached about 90 million tons globally in 2021(U.S. Geological Survey, 2022). To reduce the content of cement, various supplementary cementitious materials were used. Amongst supplementary cementitious materials (SCM), the usage of agro-waste ash appears as an exciting solution. Tobacco waste ash is one material that is suitable to replace with cement. Nearly per year, 1723.87 tons of tobacco waste were produced. In this investigation, tobacco waste ash is partially replaced by 5%, 10%, and 15% by weight of cement. The mechanical and durability properties include compressive strength (CS), split tensile strength (STS), and flexural strength (FS) were tested and compared with OPC concrete. It is concluded that mix containing 10% TWA exhibited higher strengths than compared to OPC concrete.
Evaluating the feasibility of blending fly ash and quarry dust in high-strength concrete to develop a sustainable concrete: A Study on the Mechanical and Durability Properties
Authors: Teja Prathipati S.R.R. , Paluri Yeswanth , Vijay Kunamineni , Bhavita Chowdary V
Published: October 2022

Due to the increasing demand for the mechanical properties of construction materials, High Strength Concrete (HSC) has been increasingly popular in recent decades. The raw materials utilized in the production of it consume energy and negatively affect the environment. There is a pressing need to protect the environment and conserve natural resources which are being affected by both cement manufacturing and aggregate production. In this research work, the mechanical properties of HSC blended with industrial wastes were assessed to evaluate the feasibility of incorporating industrial wastes into high-strength concrete. An attempt has been made to partially replace cement and fine aggregate in the concrete with fly ash and quarry dust, respectively, at different percentages. The workability, compressive strength, and flexural strength of the concrete, along with durability properties such as water absorption, porosity, density, acid strength loss, and acid mass loss, were investigated and reported. From the results, it can be inferred that utilizing fly ash and quarry dust up to 30% each into the high strength concrete has proved beneficial in terms of mechanical performance. Therefore, it can be concluded that replacing cement and aggregate with industrial wastes such as fly ash and quarry dust up to 30% into the HSC can be a sustainable alternative to the conventional HSC.
Static and dynamic friction coefficient in low loads and sliding speed conditions
Authors: Oprişan C M , Chiriac B , Tufescu A , Olaru D N
Published: October 2022

Using an unidirectional oscillator including a mass-spring system, the authors evidenced the important variations of the static friction coefficient both for very low contact pressure (0.002 MPa) and for high contact pressure (386 MPa).The experiments were realised by the CETR UMT-2 Tribometer with a variation of the sliding speed between 0.02 mm/s to 8 mm/s. The oscillator mass have 0.242 grams and the stiffness of the elastic spring had 77 N/m. The contact surface of the oscillator mass have a roughness Ra
= 0.1 μm and the opposite plane surfaces have roughness of Ra
= 0.1 μm and Ra
= 2.5 μm. Two types of experiments were realized: the sliding between two plane surfaces with a nominal pressure of 0.002 MPa and the sliding between a plane surface and three steel balls of 6 mm with a maximum Hertz contact pressure of 386 MPa. For very low pressure the obtained static friction coefficient varied between 0.08 to 0.3 and the dynamic friction coefficient varied between 0.08 to 0.16. For high pressure the obtained friction coefficient varied between 0.2 to 0.4 and the dynamic friction coefficient varied between 0.15 to 0.2. To simulate the sliding speed the model of Zuleeg [5] for dynamic friction coefficient has been adapted to the experimental parameters and the dynamic equation of mass displacement as function on time has been numerical integrated.
Influence of homogenization and aging parameters applied to mechanical and structural characteristics of alloy 5083
Authors: Istrate D , Lazar (Natra) C , Odagiu O P , Demian A M , Buzatu A D , Ghiban B
Published: October 2022

Aluminum based alloys of the 5xxx series are identified by a high magnesium content (4÷4.9%) which through its compounds can induce special properties of mechanical strength and resistance to various forms of corrosion. The use of 5083 aluminum alloy is especially intended for pressure vessels, products that work in special conditions of temperature and environment with increased aggressiveness, which requires the request in specifications of special properties, especially in the test of resilience. This paper aims to define the best combination of heat treatments, either homogenization or homogenization and artificial aging, in order to obtain the best mechanical and structural characteristics. Two homogenizations were carried out on the cast products (at 350°C and 450° C, respectively), each followed by artificial aging (180°C or 140°C), with different maintenance times, respectively 1h, 12h and 24h). Finally, structural correlations could be made between the values of mechanical properties (yield strength, hardness, tensile strength, elongation, microhardness and resilience) and the grain size corresponding to each structural condition.
Influence of the defect characteristic in aluminum alloy 7075 in non-destructive electromagnetic testing
Authors: Savin A , Steigmann R , Uchanin V , Stanciu M D
Published: October 2022

The paper presents the results obtained from aluminum alloy 7075 T6 using eddy current testing method (ECT). This method is based on eddy current 3x3 sensor array, commanded through PC by a data acquisition system, allowing several different delay and amplitude technique at transmission and reception. The response of each sensor is stored, ensuring details for reconstructions and imaging procedures. Based on software CIVA simulation and experiment, defect characterization is obtained using the information received by each sensor of the array and establishing the position of the flaw upon the reacting sensor from array. The signal is post processed using super resolution algorithm to enhance signal to noise ratio, thus both surface and under surface flaws shall be identified, (thin or volumetric) or having different tilting reported to the surface and correlation between theoretical and experimental results.
Determined to the microstructural and mechanical properties of deposits made of high alloy steels used in the construction of environmentally friendly hydraulic turbines
Authors: Tugui C A , Vizureanu P , Perju M C , Cimpoesu N
Published: October 2022

Research on hydraulic turbines, regardless of type, has shown that all materials used in the manufacture of parts that are components of the flow path, working in the same conditions, are subject to hydro-abrasive wear, in different proportions. The most attacked components are the blades and the chambers of the hydraulic turbines. In this paper are studied materials used in the construction of hydraulic turbine blades that have been previously deposited by the method of the electro-spark deposition with tungsten carbide (WC) electrodes. These deposits were made in order to offer the turbine blades as high a reliability as possible but also to be able to use such hydraulic turbines in the harshest conditions and which could provide as much energy as possible. A high-alloy stainless steel containing Cr and Ni was used as the basic material for the study. The raw samples from a hydraulic turbine blade and those submitted were analyzed both structurally using the optical stereomicroscope and the SEM electron microscope and chemically using the EDX probe. High alloy steel based on Cr and Ni but also WC deposits will be subjected to mechanical tests to see how they resist wear.
Practical evaluation of the vibrations of a rail mounted boom crane
Authors: Bosoancă R , Bosoancă I
Published: October 2022

Lifting devices are widely speeded in the shipbuilding industry and is compulsory to be used in order to be able to manipulate weights over 100 N on board of ships. Due to severe regulations all equipment must be designed, built and later tested for long and safe service time. The operational behaviour of lifting cranes has to be investigated and regularly controlled in order to avoid possible dysfunctions, excessive vibrations or unsafe operations on board of ships under constructions or during various lifting activities. Special procedures have been used to this purpose. The paper is focused on practical measurements of the vibrations of the main mechanisms of a number of four rail mounted boom cranes with hook 100t load and equipped with electric motors of 220 kW. In order to evaluate practical solutions to avoid vibratory behaviour, different working conditions have been taken into consideration. Based on the above-mentioned experimental program, the obtained results are reported and practical solutions are presented.
Proposed gear rack cutter for spur gear manufacturing by generating method. Part I: Theoretical and strength analysis arguments
Authors: Ciornei F-C , Alaci S , Romanu I-C , Doroftei I
Published: October 2022

The paper presents the cutting by generating of spur gears using a rack cutter with a modified geometry. In order to find the geometry of the new spur gears, a proper programme has been developed. The geometry of this spur gear is compared with one of a gear with the same parameters but obtained with a standard rack cutter. The differences between the two gears are insignificant but the new tool has a simpler geometry and a higher durability.
Design and finite element analysis of a lower arm using CATIA V5
Authors: Popescu F , Chivu R M , Uzuneanu K , Ion I
Published: October 2022

The primary role of the suspension is to ensure the comfort of the passengers but also to protect the vehicle components against mechanical shocks caused by uneven road. It is designed for stability and sudden damping. The suspension system must first and foremost ensure the safety of the passengers of the vehicle but also their comfort. The paper aims to analyze with finite elements the lower oscilating arm in order to optimize the design and find the best material.
Experimental study on combustion of an automotive diesel engine fuelled with CNG
Authors: Rotaru S
Published: October 2022

Presenting the influence of compressed natural gas (CNG) used as alternative fuel on the combustion of an automotive diesel engine represents the main objective of this paper. The paper studies brake specific energetic consumption, in-cylinder pressure and pressure rise rate, carbon dioxide, nitrogen oxides, smoke and hydrocarbons emissions at 2000 rev/min and at 40%, 55% and 70% load. Low carbon content of the alternative fuel will determine lower CO2 at all loads; NOx and smoke emissions are influenced by both energetic substitution and engine operating regime. HC emission will reach higher levels in diesel-gas mode than in conventional mode as the homogeneous percentage of the charge per cycle grows with the quantity of CNG admitted into the cylinder. In all cases in-cylinder pressure and pressure rise rate are higher in dual-fuel mode than those in conventional operating mode due to higher quantity of premixed charge developed during the ignition delay phase. The higher LHV (lower heating value) and the gaseous state of CNG will determine at all loads lower brake specific energetic consumption. Smoke emission will be negatively influenced in low to medium loads but in high loads it will drop by more than 30 percent.
Elimination of disturbances due to changes in air flow in a wind turbine with hydrostatic transmission
Authors: Dumitrescu C , Chiriţă A P , Şefu Ş , Baciu I M , Rădoi R
Published: October 2022

Hydrostatic power transmission between the rotor of a wind turbine and the generator, which can be placed on the ground, is a way to reduce the cost of installing a turbine, reducing the mass placed at height. The article shows the ability of a hydrostatic transmission to cope with a disturbance due to the change in the air flow that drives the turbine rotor. When increasing the air flow, which would normally lead to an increase in the drive speed of the electric generator, by adjusting the geometric volume of the hydraulic pump connected to the wind rotor with a PID regulator, the drive speed of the generator is kept constant. The load of the electric generator is also simulated hydraulically.