Behavior Of Different Kinds Research Articles

Dynamic behavior of different kinds of rack vehicles

For the sake of improving climbing ability of railway vehicle, gear-rack system is added to traditional vehicle to form rack vehicle. Aiming at the influence of the different gear-rack systems on the rack vehicle dynamic behavior, this article considers the gear-rack meshing impact based on the analysis of the generation mechanism of the gear-rack meshing excitation. The gear-rack meshing model and four kinds of rack vehicle coupled dynamics models are established, and the model is verified by experiments. Based on the model, the gear-rack nonlinear meshing behavior and rack vehicle dynamics characteristic of two kinds of Strub system, double row teeth Abt system and Locher system under different slopes is explored. and the dynamic characters of the rack vehicle system is analyzed. Finally, the optimal gear-rack system is obtained by comparing the dynamic behavior of different vehicles. The results show that: The dynamic behavior of rack vehicles with different gear-rack systems is significantly different, and Locher system has the optimal dynamic behavior. The gear-rack nonlinear meshing behavior and the vehicle safety of the coaxial Strub system and the double row teeth Abt system are poor, which are obviously affected by the track irregularity. The impact of the gear-rack nonlinear contact force of the coaxial Strub system reaches 29.8 kN. The maximum wheel/rail vertical force of the double row teeth Abt system reaches 51.4 kN. The vehicle stability of the different shaft Strub system is the worst, and the maximum stability index is 1.368. The conclusion of this paper provides theoretical support for the design and safe operation and maintenance of the world’s mountainous rack railway.

A three-phase model for biofilm formation on a porous solid surface

We investigate the growth kinetics of bacterial biofilms on porous substrates. A three-phase model is developed, which accounts explicitly for the cell phase, extracellular matrix (ECM), and nutrient-rich aqueous phase. We use the thin-film approximation as the characteristic height of the biofilm is much smaller than its characteristic radius. We use the 2D axisymmetric model to capture biofilm growth on a porous agar substrate. Our model accounts for osmotic flux and predicts the spatiotemporal variations of the volume fractions of the different phases and the nutrient concentrations in the biofilm and the substrate. An increase in surface tension helps redistribute biomass radially. Our model captures the behavior of different kinds of biofilms: films characterized by low (yeast) and high (bacterial) ECM content. The predictions of our model are quantitatively validated with the experimental data from the literature. Our model provides insights on the role of different parameters on biofilm growth, which can be used to develop strategies to prevent or accelerate biofilm formation on surfaces.

Natural swarms in 3.99 dimensions

The renormalization group is a key set of ideas and quantitative tools of statistical physics that allow for the calculation of universal quantities that encompass the behaviour of different kinds of collective systems. Extension of the predictive power of the renormalization group to collective biological systems would greatly strengthen the effort to put physical biology on a firm basis. Here we present a step in that direction by calculating the dynamical critical exponent z of natural swarms of insects using the renormalization group to order ϵ = 4 − d. We report the emergence of a novel fixed point, where both activity and inertia are relevant. In three dimensions, the critical exponent at the new fixed point is z = 1.35, in agreement with both experiments (1.37 ± 0.11) and numerical simulations (1.35 ± 0.04). Our results probe the power of the renormalization group for the quantitative description of collective behaviour, and suggest that universality may also play a decisive role in strongly correlated biological systems.

Coal or Biomass? Case Study of Consumption Behaviour of Households in the Czech Republic

Renewable sources play a crucial role in the decarbonisation process of the current linear economy, aimed at reaching the 2030 climate objectives and fulfilling the EU’s long-term strategy of achieving carbon neutrality by 2050. All economic subjects, including households, can contribute to the Green Deal goals. The main goal of this paper is to evaluate households’ consumption of energy sources for heating purposes in the Czech Republic in the period 2003–2020 and depict possible drivers of switching to biomass. For this, various data were collected, such as data published by the Czech Statistical Office, ministries, and other national authorities, as well as data from Eurostat. Concerning methods, data analysis, correlation analysis, and regression analysis were used. Different models focus on the substitution effect, rebound effect, and behaviour of different kinds of households. The results show a substitution effect connected with the consumption of coal, electricity, and biomass for heating purposes. Many households substituted coal for biomass in the observed period. On the other hand, the environmental impact of such substitution is not significant, as carbon emissions and emissions of other pollutants are stable. The substitution of fuels should be accompanied by technological change, e.g., improvement of combustion boilers. Moreover, households of pensioners are the key economic subjects with the highest impact on biomass consumption for heating purposes. Against this background we recommend policies to support households in replacing their boilers for more environmentally friendly ones.

A bioinspired model for the generation of a motivational state from energy homeostasis

Appetitive motivation is a process inherent to human beings, which stimulates behaviors directed at searching, pursuing, and achieving specific objectives based on a set of impulses. Consequently, the motivational process has been considered part of the control system in some cognitive architectures because it can influence the execution of goal-directed behaviors of different kinds. Different motivational computational systems integrate physiological needs and environmental conditions to produce human-like behavior in artificial agents. However, these motivational computational systems limit abstract properties defining a motivational state; consequently, the adaptability characterizing motivated human behavior does not arise. In this research line, this article proposes a bioinspired model for generating the motivational state from the physiological condition, capable of triggering processes involved in developing appetitive behavior. The proposed system incorporates bloodstream and viscerosensory biomarkers to represent a motivational state of hunger regulated by energy homeostasis or balance control. The proposed model is based on neuroscientific studies and implemented under a distributed paradigm emulating the way it happens in living beings. The validation of the proposed model’s functioning uses study cases comparing the proposal’s results with neuroscientific evidence.

Significance of applying theory of planned behaviour, theory of hexaco, religiosity and tawakal in COVID-19 pandemic

Research dealing with various aspects of theory of Hexaco, theory of planned behavior, tawakal and religiosity are reviewed, and some unresolved issues are discussed in coping of COVID 19 disease in Malaysia. In broad terms, the theory is found to be well supported by empirical evidence. Intentions to perform behaviors of different kinds can be predicted with high accuracy from attitudes toward the behavior, subjective norms, and perceived behavioral control; and these intentions, together with perceptions of behavioral control, account for considerable variance in actual behavior with religiosity aspect. Theory of Hexaco, attitudes, subjective norms, and perceived behavioral control, religiosity and tawakal are shown to be related to appropriate sets of salient behavioral, normative, and control beliefs about the behavior, but the exact nature of these relations is still uncertain. Expectancy. value formulations are found to be only partly successful in dealing with these relations. Optimal rescaling of expectancy and value measures is offered as a means of dealing with measurement limitations. Finally, inclusion of past behavior in the prediction equation is shown to provide a means of testing the theorys sufficiency, another issue that remains unresolved.

The influence of the addition of aluminum anodizing waste on the friction and emission behavior of different kinds of friction material formulations

The study focuses on the characterization and one-of-a-kind utilization of aluminum anodizing waste (AAW) in different friction material formulations. Through TGA and FT-IR analysis, the AAW was observed to have a dominant presence of hydroxide, sulfate hydrate, and a fraction of alumina. After heat treatment at 400 ℃ for 4.5 h, the AAW also constituted of AlOx, obtained from the conversion of hydroxides. The AAW was included in two kinds of friction material compositions – a basic composition (BC) with few constituents, and a commercial composition (CFM), wherein, the AAW was added at 12, 24, and 32 wt% of variation, and subjected to friction, wear, and emission analysis. The tests were conducted on a pin on disc testing equipment at 1.51 m/s, 1 MPa, and room temperature testing conditions. The analysis with BC revealed the mild abrasive nature of the AAW, along with acceptable friction, wear, and emission characteristics. With the CFM, the steady state CoF trends, permissible CoF, pin and disc wear, and desirable emission characteristics were observed with 12 wt% addition of AAW. Higher AAW content led to the degradation of wear and emission characteristics of the CFM specimens. Through this preliminary investigation, the possibility of the recycling/utilization of AAW was explored comprehensively, paving the path for further exploration and feasibility analysis of the inclusion of AAW in braking applications.

Dynamic characteristics of multi-arc thermal plasma in four types of electrode configurations

The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers. Combined with a high-speed camera and an oscilloscope, which acquire optical and electric signals synchronously, the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated. Also, the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method. It is found that the cathodic arcs mainly show a contracting state, while the anodic arcs have a trend of transition from shrinkage to a diffusion-like state with the increase of the discharge current. As a result of the adjustment of the electrode configuration, a high temperature region formed in the center of the discharge region in configurations of adjacent electrodes with opposite flow distribution and opposite electrodes with swirl flow distribution due to severe fluctuation of arcs. The discharge voltage rises with increased discharge current in this novel multi-arc plasma generator. It is also found that anode ablation mainly occurs on the conical surface at the copper electrode tip, while cathode erosion mainly occurs on the surface of the inserted tungsten and the nearby copper.

Compositional Ligno-cellulosic behaviour of some residual biomass

The present study analyzes the compositional lingo-cellulosic behaviour of different kinds of biomass. Five types of biomass were selected for this investigation: wheat straw, coconut husk, tea waste, coconut shell, and eucalyptus shell. This study found that only lignin content contributes to the heating value, then cellulose and hemicellulose. There is not a direct relationship between the heating value of biomass and the cellulose and hemicellulose content. However, because lignin has a 30% greater energy content than cellulose and hemicellulose, it directly impacts the biomass's heating value. Because lignin is the most stable and complex of the three biomass components, its concentration is thought to be the most important determining factor in the thermo-chemical process. All the samples exhibit three distinct peaks, namely, moisture loss at 70 °C, hemicellulose degradation at 300 °C, and maximal breakdown of the piece at 365 °C, as determined by DTG analysis.

A first quantitative approach for detecting volumetric defects in additive manufactured metal samples by using active thermographic technique

This work is focused on the quantitative analysis of defects produced in metal samples of AISI 316L with Laser Powder Bed Fusion (L-PBF) additive manufacturing (AM) process by means of active thermographic techniques. A simple and common set-up with 2 flash lamps and a cooled sensor has been used to analyse the differences between planar and volumetric defects. In particular, the presence of imprinted spheres containing inside non-sintered metallic powder has been compared with those of similar cylinders in size and depth, induced in similar samples. Furthermore, the differences in terms of thermal contrasts have been studied between the cylinder manufactured as an internal defect with powder inside, against the same geometry, but with a small channel for the discharge of the non-melted material. The analysis of the thermal signal and the application of post processing algorithms allowed us to identify the thermal features suitable for describing the behaviour of different kind of defects, typical of the process.

Analysis of a Preliminary Design Approach for Conformal Lattice Structures

An important issue when designing conformal lattice structures is the geometric modeling and prediction of mechanical properties. This paper presents suitable methods for obtaining optimized conformal lattice structures and validating them without the need for high computational power and time, enabling the designer to have quick feedback in the first design phases. A wireframe modeling method based on non-uniform rational basis spline (NURBS) free-form deformation (FFD) that allows conforming a regular lattice structure inside a design space is presented. Next, a previously proposed size optimization method is adopted for optimizing the cross-sections of lattice structures. Finally, two different commercial finite element software are involved for the validation of the results, based on Euler–Bernoulli and Timoshenko beam theories. The findings highlight the adaptability of the NURBS-FFD modeling approach and the reliability of the size optimization method, especially in stretching-dominated cell topologies and load conditions. At the same time, the limitation of the structural beam analysis when dealing with thick beams is noted. Moreover, the behavior of different kinds of lattices was investigated.

Scrutinizing Self-Assembly, Surface Activity and Aggregation Behavior of Mixtures of Imidazolium Based Ionic Liquids and Surfactants: A Comprehensive Review.

The desire of improving various processes like enhanced oil recovery (EOR), water treatment technologies, biomass extraction, organic synthesis, carbon capture etc. in which conventional surfactants have been traditionally utilized; prompted various researchers to explore the self-assembly and aggregation behavior of different kinds of surface-active molecules. Ionic liquids (ILs) with long alkyl chain present in their structure constitute the advantageous properties of surfactant and ILs, hence termed as surface-active ionic liquids (SAILs). The addition of ILs and SAILs significantly influence the surface-activity and aggregation behavior of industrially useful conventional surfactants. After a brief review of ILs, SAILs and surfactants, the prime focus is made on analyzing the self-assembly of SAILs and the mixed micellization behavior of conventional surfactants with different ILs.

JOHNSON–COOK MODEL COMBINED WITH COWPER–SYMONDS MODEL FOR BONE CUTTING SIMULATION WITH EXPERIMENTAL VALIDATION

Constitutive models are widely used to predict the mechanical behavior of different kinds of materials. Although the Johnson–Cook model for bovine bone and Cowper–Symonds model for human thoracic rib and tibia was developed, the predictability of these models was found good only at particular strain rates. This study addresses this lack of information by investigating the Cowper–Symonds model, Johnson–Cook model, and Johnson–Cook model combined with Cowper–Symonds model at different strain rates to utilize in the bone cutting simulation. Specimens prepared using two rear femurs harvested from a 3.50-year-old bovine were investigated at different strain rates (0.00001–1/s). A comparative study made among the stresses predicted from these models showed 29.41%, 10.91%, and 11.11% mean absolute percentage errors using Cowper–Symonds model, and 2.03%, 7.19%, and 3.62% mean absolute percentage errors using Johnson–Cook model, respectively, at 0.0001, 0.001 and 1/s strain rates. However, the Johnson–Cook model combined with the Cowper–Symonds model predicted the stress with a maximum of only 2.03% mean absolute percentage error. The potential of each model to utilize in the orthogonal bone cutting was also evaluated using Ansys® and found that the combined model predicted the cutting force close to experimental cutting force with minimal error (5.20%). The outcomes of this study can be used in the surgical practice and osteotomy procedure before commencing actual surgery.

A Review on Tensile Behavior of Different Kinds of Fiber Reinforced Concrete

A Review on Tensile Behavior of Different Kinds of Fiber Reinforced Concrete

Rebar corrosion behavior of coral aggregate seawater concrete by electrochemical techniques

Purpose Coral aggregate seawater concrete (CASC) is a new type of lightweight aggregate concrete that is becoming widely used in reef engineering. To investigate the corrosion behavior of different kinds of rebar in CASC exposed to simulated seawater for 0-270 d, the electrochemical techniques, including linear polarization resistance (LPR) technique and the electrochemical impedance spectroscopy (EIS), were used in the present work. Design/methodology/approach The electrochemical techniques, including LPR technique and the EIS, were used in the present work. Findings Based on the time-varying law of linear polarization curves, self-corrosion potential (Ecorr), polarization resistance (Rp), corrosion current density (Icorr), corrosion rate (i), and the characteristics of EIS diagrams for different types of rebar in CASC, it can be found that the anti-corrosion property of them can be ranked as epoxy resin coated steel > 2205 duplex stainless steel (2205S) > 316 L stainless steel (316 L) > organic coated steel > ordinary steel. Additionally, the linear regression equation between Rp and charge transfer resistance (Rct) was established. Finally, the EIS corrosion standard of rebar was established from the LPR corrosion standard, which provides a direct standard for the EIS technique to determine the condition of rebar in CASC. Originality/value The linear regression equation between polarization resistance and charge transfer resistance was established. And the EIS corrosion standard of rebar was established from the LPR corrosion standard, which provides a direct standard for the EIS technique to determine the condition of rebar in CASC.

Comparison between long and short beam flexure of a carbon fibre based FML

A Fibre metal laminate (FML) consists of a stack of metal sheets alternating to composite material layers: in such a manner, the best characteristics of both constituents are combined together. In this work, the flexural behaviour of different kinds of FMLs was investigated. In particular, both long beam and short beam specimens were produced and tested, since the length-to-thickness ratio influences the stress type arising in the material and, consequently, the failure mode. Moreover, the influence of both the composite/metal interface and the thickness of the layers was analysed. It was found that the structural adhesive was deleterious for the flexural strength of the long beam, while it improved the behaviour of the short one. As concerns the thickness and the distribution of the layers, this factor was unaffecting for the short beam specimen, while it was decisive for the long beam one. A micrographic analysis was carried out on the tested specimens, in order to characterize the failure mode. It was found a preponderance of fibre breakage in the long beam, while in the short one the failure of the metal/composite interface was prevailing.

Critical Areas of Proliferation of Single Cells on Micropatterned Surfaces and Corresponding Cell Type Dependence.

Material cues to influence cell proliferation are a fundamental issue in the fields of biomaterials, cell biology, tissue engineering, and regenerative medicine. This paper aims to investigate the proliferation of single mammal cells on micropatterned material surfaces. To this end, we prepared cell-adhesive circular microislands with 20 areas on the nonfouling background and systematically examined adhesion and proliferation behaviors of different kinds of single cells (primary stem and nonstem cells, cancer and normal cell lines) on micropatterns. On the basis of the analysis of experimental data, we found two critical areas about cell proliferation: (1) the critical spreading area of cells from almost no proliferation to confined proliferation, denoted as AP and (2) the critical spreading area of cells from confined proliferation to almost free proliferation, denoted as AFP. We further summarized the relative size relationship between these two critical areas and the characteristic areas of cell adhesion on both patterned and nonpatterned surfaces. While proliferation of single primary cells was affected by cell spreading, those cell lines, irrespective of normal and cancer cells, did not exhibit significant cell-spreading effects. As a result, this study reveals that proliferation of single cells is dependent upon spreading area, in particular for primary cells on material surfaces.

Influence of Fine Fuel Particles on Ash Deposition in Industrial-Scale Biomass Combustion: Experiments and Computational Fluid Dynamics Modeling

This work focuses on the contribution of fuel particles with diameters smaller than 1 mm on the ash deposition behavior of different kinds of biomass feedstock. Special emphasis lies on their impac...

On crack propagation monitoring by using reflection spectra of AFBG and UFBG sensors

Due to their light weight, small size and immunity to electromagnetic interference, Fiber Bragg Gratings (FBG) have shown great potential in structural health monitoring (SHM) area. Ordinarily, FBGs are used as the quasi-distributed sensors to detect structural damage by central wavelengths shifting, which has robust problem in real engineering application. It is found that the FBG reflection spectra can also be distorted with the non-uniform strain field caused by crack. Multiple indices can be extracted from the reflection spectra which can provides more information on the crack propagation. However, till now no researches have been investigated regarding the behaviors of different kinds of FBGs for crack propagation monitoring based on the FBG reflection spectra. In this paper, behaviors of the apodized FBG (AFBG) and the uniform FBG (UFBG) sensors for structural crack propagation monitoring are investigated. The reflective spectral behaviors of both UFBG and AFBG sensors under crack-generated non-uniform strain are illustrated by simulation and experiment. Three spectra indices, namely the central wavelength shift, the ratio of side lobe to main lobe and the information entropy, are proposed to indicate the propagation of the crack. The results show the UFBG sensors have better performance than the AFBG sensors which are more suitable for crack propagation monitoring.

Experimental analysis of the hydrodynamic effect during start-up of fixed geometry thrust bearings

Abstract Most of the investigations on thrust bearings were performed under a steady-state condition and this regime is now well understood. Contrary to this, the behavior during the first period of start-up is sparsely studied. Start-ups of thrust bearings are critical periods where a mixed lubrication regime occurs. This regime can be detrimental for the lifetime of the system. It is usually mentioned in the literature that the textures act as micro reservoirs which can be beneficial to help lift-up during start-up. This is an intuitive hypothesis and there are no experimental results to prove it. This study uses an experimental approach in order to analyze the behavior of different kinds of thrust bearings with fixed geometry. It mainly focuses on the capability of textured thrust bearings to lift up during start-up. This study shows that only specific texture geometry can help the formation of a fluid film. The results are compared to those obtained with classical geometries like tapered land, pocketed and untextured flat-land thrust bearings. The original results show a relatively good ability of flat-land thrust bearings to generate a lift-up during the start-up period. An experimental device is used to measure, at high frequency, the friction torque as well as the electrical resistance across the fluid film to determine the lubrication regime. The comparative analysis allows us to explain the factors which modify the contact.