Thermal Extrusion Research Articles

Integration of Thermal Treatment and Extrusion by Compounding for Processing Various Wastes for Energy Applications

Integration of Thermal Treatment and Extrusion by Compounding for Processing Various Wastes for Energy Applications

Study of thermally developed flow of viscous fluid over a porous stretching surface contacting gyrotatic microorganisms using buongiorno model

Recent trend in advanced nanotechnology has developed the thermal consequences of nanoparticles due to increasing significance in various engineering and thermal extrusion systems. In this continuation, two-dimensional flow of viscous nanoliquid in the presence of gyrotactic micro-organisms encountered by a porous stretched surface is addressed numerically. The novel aspects of Brownian diffusion and thermophoresis are studied by using Buongiorno model. The thermal radiation impact is imposed in the energy equation. A set of pertinent transformations has been suggested to transform the governing non-linear partial differential equations into system of non-linear ordinary differential equations. A famous numerical method, finite difference technique, is engaged to acquire the numerical solution of modeled dimensionless equations. The flow analysis for effects of numerous prominent parameters on velocity, temperature, concentration and motile micro-organisms profiles is presented graphically. In the presence of thermal radiation, velocity profiles detract with augment of bioconvection Rayleigh number and buoyancy ratio parameter, while opposite trend is observed for boosting the Grashoff number. The porous medium as well as the radiation enhance the fluid temperature.

Nonlinear thermal radiation and activation energy significances in slip flow of bioconvection of Oldroyd-B nanofluid with Cattaneo-Christov theories

Recently, nanofluids are an effective source of enhancing the thermal transportation systems associated with industrial and engineering phenomena. With the nanoscale size and effective thermal properties, the nanomaterials convey exclusive beneficial applications in heat exchanges, coolant processes, medical treatment, electronic cooling systems, energy production, etc. Keeping all such motivating significances of nanoparticles in mind, this research presents the thermal aspects of Oldroyd-B nanofluid with applications of bioconvection phenomenon over a convectively heated configuration when the slip effects are more dominant. The bio-convective nanofluid model is further extended by incorporating the thermal radiation relations in nonlinear form and activation energy. The modifications in heat and mass equations are suggested in view of modified Cattaneo-Christov theories. The magnetic force and porous medium applications are also entertained. The convective conditions are imposed on accessing the flow dynamically. The numerical simulations via shooting technique by using MATLAB software are performed with convincing solution accuracy. The physical objective in view of all parameters that govern the flow model is presented in graphs and tables. The obtained theoretical results reflects applications in thermal extrusion processes, power plants, enhancing the heat/mass process, information technology, chemical processes, pharmacological processes, cooling and heating systems, solar energy production, bio-technolgy applications like enzymes, biofules etc.

Pasta: Raw materials, processing and quality improvement

Pasta is a ready to eat extruded product having higher nutritional properties. It is really suited for daily balance diet because of the higher concentration of unsaturated fatty acid. Mixing, extrusion, drying, cooling and packaging are the major steps used in the production of pasta. Pasta can be produced from different cereals like sorghum, maize, wheat, rice, oats and the addition of these cereals can change the textural, functional, physiochemical properties and microstructure of pasta. The yellow colour is the most acceptable range of pasta by customers. Pasta helps to Lower glycaemic index and type 2 diabetics and reduce abdominal obesity. Pasta is a nutritious food helps to reduce the risk of developing Alzheimer’s disease.This review paper provides an updated information about the different cereals used, fortification of pasta with different plant and animal sources, production technologies, effect of thermal treatments, extrusion conditions, microstructure, and colorimetry of pasta.

Preform design and microstructure-property analysis for isothermal extrusion of complex box-shaped components

The design of preform plays a key role in the precision forming of complex-shaped components with thin walls and large areas of webs. In the present work, two typical kinds of box-shaped forgings of 5A06 aluminum-alloy were selected as research objects, including the symmetric rectangular base forging and the asymmetric arc cover forging. The preform design method was proposed during isothermal back extrusion of boxlike forging, in which metal flow law of billets with equal thickness revealed by finite element (FE) simulation was quite useful for the billet design. The simulation results successfully predicted folding defects at the bottom of the base forging and inadequate filling at lateral walls of the cover forging, which were caused by inappropriate billet geometry and loading mode. According to the simulation and experimental results, the reverse loading of the rectangular base billet with variable thickness avoided the appearance of the folding at the bottom. The base forging without defects was formed successfully under reverse loading by using the billet with four 60 mm × 90 mm × 5 mm bosses and 15° transition surfaces, while the cover forging without defects was formed successfully by using the billet with 15° transition surfaces and two bosses whose heights were both 48 mm. Both the two boxlike forgings formed with modified billets exhibited perfect distribution of flow lines. Meanwhile, the lateral walls and webs possessed higher tensile strength, higher elongation, finer and more elongated grains than raw material. Therefore, the thermal backward extrusion was an effective process to precisely form complexly boxlike rib/web workpiece.

Dynamics of unsteady reactive flow of viscous nanomaterial subject to Ohmic heating, heat source and viscous dissipation

Owing to the improved thermophysical properties of nano-materials, the nanofluid convey novel applications in industries, engineering as well as bio-medicals. With high efficiency performances, the nanoparticles include applications in various cooling and heating systems, energy production, aerospace engineering, thermal extrusion, bio-medical applications like treatment of diseases, brain tumour, surgical applications and many more. Moreover, the magneto-nanofluids have the characteristics in the flow of blood in the human artery. The current analysis deals with the free convective unsteady flow of viscous nanofluid subject to the magnetic force over a vertical plate in presence of porous space. The heat transfer phenomenon is accessed by utilizing the additional features like Joule heating, viscous dissipation and absorption coefficients. In addition to the volume fraction of the nanofluid, the effect of the chemical reaction is also introduced. The solution procedure for the modified time-dependent boundary value problem is performed by using the code in-build MATLAB namely Built-in-Shooting method. The change in velocity, temperature and concentration of nano-materials is examined through various graphs. The physical consequences of flow parameters like porosity parameter K p 1 ⩽ K p ⩽ 3 , thermal Grashoff number Gr 1 ⩽ G r ⩽ 3 , solutal Grashoff number Gc 1 ⩽ G c ⩽ 3 , magnetic field parameter M 1 ⩽ M ⩽ 3 , thermal radiation parameter Nr 0.1 ⩽ N r ⩽ 1 , radiation absorption parameter Q 0 ⩽ Q ⩽ 0.5 , Prandtl number Pr 2 ⩽ Pr ⩽ 21 , Eckert number Ec 0 ⩽ E c ⩽ 0.4 , heat source S - 0.2 ⩽ S ⩽ 0.2 , chemical reaction parameter Kc 1 ⩽ K c ⩽ 4 , nanoparticles volume fraction ϕ 0.0 ⩽ ϕ ⩽ 0.1 , Lewis number Le 1 ⩽ L e ⩽ 10 on velocity, temperature and concentration distributions is graphically analyzed. The results show that skin friction coefficients decline with buoyant forces. A lower numerical variation in Nusselt number is resulted with heat source parameter. Moreover, a sharp fall in nanofluid concentration is noticed with increment of chemical reactants and Lewis number.

On the Influence of Manufacturing Strategy of 3D-Printed Polymer Substrates on Cold Spray Deposition

PMCs are anisotropic and heterogeneous structures with excellent performances in terms of mechanical strength and stiffness, coupled with reduced weight, widely used in engineering sectors. The use of PMCs can be further extended by improving their surface properties such as electrical conductivity, erosion, radiation and lightning protection. In this context, the surface metallization seems to be best solution. In particular, the cold spray (CS) technique candidates as a potential method for the manufacturing of a metal coating on PMCs’ surface. However, the design and the manufacturing methods of PMCs can play a crucial role for an effective metallization through CS. The additive manufacturing technologies for composite materials can be used to manufacture customized reinforced polymer-based panels, like PMCs; the most common method for printing them is the Fused Filament Fabrication (FFF) technique which relies on the thermal extrusion of a thermoplastic feedstock from a mobile heated nozzle. Therefore, this research activity aims to manufacture customized PMCs panels by using FFF technology for the substrate and the cold spray technique for the metallization in order to study the influence of the substrate manufacturing strategy on CS deposition process. For this purpose, three kind of 3D-printed PMCs were manufactured through the FFF technology by varying the percentage fill of the Onyx polymeric matrix and aluminum powders were sprayed on the substrates with a low-pressure cold spray (LPCS) system; both FFF and CS process parameters were varied to study the process in its wholeness. Microscope analyses were carried out to analyze the influence of the manufacturing strategy on the coating quality.

Manufacturing Of Aluminum Coating On 3D-Printed Onyx With Cold Spray Technology

Composite materials are widely used as main parts and structural components in different fields, especially for automotive and military applications. Although these materials supply different advantages comparing to the metals, their implementation in engineering applications is limited due to low electrical and thermal properties and low resistance to erosion. To enhance these above-mentioned properties, the metallization of composite materials by creating a thin metal film on their surface can be achieved. Among different coating deposition techniques, Cold Spray appears to be the most suitable one for the metallization of temperature-sensitive materials such as polymers and composites with a thermoplastic matrix. This process relies on kinetic energy for the formation of the coating rather than on thermal energy and consequent erosion and degradation of the polymer-based composite can be avoided. In the last years, a new method to produce composite materials, as known as Fused Filament Fabrication (FFF), has been developed for industrial applications. This technique consists of a 3D printing process that involves the thermal extrusion of thermoplastic polymer and fibers in the form of filaments from a heated mobile nozzle. The implementation of this new technique is leading to the manufacturing of customized composite materials for the cold spray application. In the presented experimental campaign, Onyx material is used as a substrate. This material is made of Nylon, a thermoplastic matrix, and chopped carbon fibers randomly dispersed in it. Aluminum powders were cold sprayed on the Onyx substrate with a low-pressure cold spray (LPCS) system. This study aims to investigate the possibility of the metalizing 3D-printed composite material by cold spray technology. For this purpose, optical and microscopical analyses are carried out. Based on the results, the feasibility of the process and the influence of the morphology of the substrate are discussed, and optimal spraying conditions are proposed.

Impact of thermal extrusion and microwave vacuum drying on fatty acids profile during fish powder preparation.

The current study aimed to optimize the process for ready‐to‐eat extruded fish powder preparation and to ascertain the impact of two methods on fatty acid profiles. For the investigation, Labeo rohita (Rohu) fish was first minced, extruded, and microwave vacuum‐dried. The results show that the yield for extruded fish powder (EFP) fluctuated from 22.32% to 29.07%. The maximum retention for docosahexaenoic acid (DHA), arachidonic acid (AA), and eicosapentaenoic acid (EPA) was 3.24 ± 0.08 g/100 g lipids, 2.74 ± 0.05 g/100 g lipids, and 1.24 ± 0.09 g/100 g lipids, by using different extrusion parameters. Moreover, nonsignificant changes were observed during 0 days, and 1 and 3 months of storage (at 4°C and 25°C) for DHA, AA, and EPA, whereas significant results were recorded for the samples stored for 6 months at 25°C. Also, the maximum peroxide value (PV) and thiobarbituric acid reactive substance values (TBARS) were 1.72 ± 0.04 meq/kg fat and 0.135 ± 0.008 mg malondialdehyde/kg fat. It is anticipated from the outcomes that the study will be helpful to prepare value‐added food products in future studies.

Induced MHD impact on exponentially varying viscosity of Williamson fluid flow with variable conductivity and diffusivity

In this study, we assumed a thermal energy system with variable controlling properties which effect the entire system. One of the best applications of thermal energy system is heat exchanger. A good heat exchanger is a big challenge over the past years, due to enlarged public request on improving energy efficiency and decreasing energy. Normally, heat exchangers are used in the transmission of heat between two or more fluids [46]. Furthermore, the analysis of MHD flow of an electrically conducting fluid due to the thermal system is significant in current metallurgy and metal-working methods. Due to large amount of applications, variable thermo-physical properties of induced magnetic field in Williamson fluid flow is studied. The achieved system is partial differential, which is converted into ordinary differential equations by using the transformations. Then the attained system is solved by using shooting method. The thermal extrusion system contains velocity, concentration, and temperature fields. The associated controlling parameters contain small parameter, magnetic field, the reciprocal magnetic Prandtl number, variable viscosity parameter, Williamson parameter, small concentration parameter and Schmidt number. The outlined results deliver good thermal impact on entire system for minor and big values of these pertinent parameters. Williamson fluid model is executed to examine the properties of shear thinning fluids. It is noticed that a big reduction is noticed in velocity profile for large values of variable viscosity parameter, Williamson parameter and magnetic parameter. Moreover, the reciprocal magnetic Prandtl number reduces the magnetic profile. The temperature and concentration small parameters show enhanced impact on temperature and concentration profiles. Comparison of present thermal system is considered for limited values of these parameters.

Extrudate dehydration rate increase by modernization of the extruder vacuum chamber

This paper proposes to upgrade the vacuum chamber of the extruder to enhance the impact of thermovacuum effect on extrudate due to dispensing air into the working volume of the vacuum chamber of the extruder. An air valve is installed in the upgraded extruder chamber. This valve allows faster removal of the wet steam with the extrudate surface. Analytical expressions, which allow determining the volumetric flow rate of intake air of the machine in the vacuum chamber and determining its influence on the basic design and technological parameters of the system, were obtained. The obtained results can be useful and taken into account in the process of subsequent theoretical studies of extruders with a vacuum chamber and will improve the efficiency of machines that perform thermal vacuum extrusion of plant materials.

Thermally developed generalized Bödewadt flow containing nanoparticles over a rotating surface with slip condition

Recent advanced nanotechnology trends have developed thermal implications of nanoparticles as they are more and more important in different engineering and thermal extrusion technologies. Nanofluids are the best substitute to improve the thermal conductivity of conventional heat transfer base liquids. Therefore, the present article addresses the comparative study for the heat transfer phenomena in the thermal boundary layer due to a generalized VF of NF over an infinite rotating disk with generalized SC. The motion is generated by the fluid rotation like a solid body with a constant angular velocity Ω at a sufficiently extensive distance from the disk's surface. The nanoparticles Cu and TiO2 are considered with water-based NF subjected to thermal radiation. Finite difference-based method bvp4c is employed to solve the obtained non-linear ODEs numerically. The analysis of various flow parameters on the velocity components and temperature fields at the surface of the disk is outlined through graphical and tabular outcomes. The findings reveal that suction reduces the velocity overshoot and dampens the fluctuation.

Integration of Group Method Analysis and Rough Sets Theory to Investigate Heat and Mass Transfer of the Flow of a Non-Newtonian Nanofluid towards a Vertical Stretching Surface

This work reports how to utilize rough set theory and group method analysis for generating a set of rules to investigate heat and mass transfer of mixed convection stagnation point flow of a non-Newtonian nanofluid towards a vertical stretching surface. By utilizing group method analysis, the main partial differential equations which describe the flow are rehabilitated to nonlinear Ordinary Differential Equations (ODEs). Then, the resultant nonlinear ODEs are solved numerically by applying the implicit finite-difference scheme. The numerical values thus obtained are depicted in tabular form and the basic principles of rough sets are applied to get all reducts and finally a group of generalized rules are extracted to predict the value of local Nusselt number and local skin-friction coefficient. The outcomes demonstrate the novelty of the current work which can be summarized as hybridization of group method analysis and rough set theory to use in the field of fluid dynamics effectively. The resultant set of generalized classification rules which performed with basic logic functions can be considered as knowledge base with high accuracy and may be valuable in many engineering applications like power production, thermal extrusion systems and microelectronics.

Internal energy change in Darcy-Forchheimer Carreau fluid model past a vertical stretching sheet with magnetic dipole and variable thermo-physical properties

In this research work, we consider a thermal energy system with a different controlling effects which impact the entire system. These controlling effects include the variable thermo-physical properties of Carreau fluid flow causing change in internal energy (viscous dissipation) of the permeable thermal conversion problem. The disturbance in fluid’s motion is created by applying magnetic dipole. After converting the thermal system from partial differential into ordinary differential, the developed system is solved by using midpoint method in combination with bisection. The thermal energy extrusion system consists of velocity and temperature fields. The related controlling parameters include variable thermal conductivity parameter, Darcy-Forchheimer parameter, Eckert number, mixed convection parameter, variable viscosity parameter, ferrohydrodynamic interaction variable, Weissenberg number, curie temperature and Prandtl number. The sketched results provides good thermal effects on entire system for small and large values of these parameters. Carreau fluid model is performed to analyse the properties of shear thinning and thickening. It is noticed that velocity distribution reduces for large values of Williamson parameter, ferrohydrodynamic interaction variable, porosity parameter and variable viscosity parameter but opposite behavior is achieved for large values of Darcy-Forchheimer parameter. The temperature profile shows great impact by emerging parameters appearing on it. The small parameter and Eckert number shows enhancement in temperature distribution, but large reduction is noticed in temperature distribution for greater values of Prandtl number and curie parameter. Comparison of current thermal system is calculated for limited values of these parameters.

Influence of bioconvection on Maxwell nanofluid flow with the swimming of motile microorganisms over a vertical rotating cylinder

In recent times, bioconvection phenomenon through the use of nanomaterials has encountered significant manufacturing and technical applications. Bioconvection has several applications in bio-micro-system, due to the enhancement in mass transformation and mixing, which are crucial problems in different micro-systems. The aim of current article is to scrutinize the bioconvection phenomenon in 3D Maxwell nanofluid flow with useful characteristics of mixed convection, activation energy, motile microorganisms and solutal boundary conditions. The flow problem focused on the related laws, outcomes in a series of PDEs which have also been delayed in ODE's structure. The numerical method based on a shooting technique is applied to implement a bvp4c solver using the computational software MATLAB. Shooting tactic is utilized to construct the numerical arrangement of subsequent problem. The mathematical division for the local Nusselt number, the motile microorganism's number, and the local Sherwood number is provided when applying different characteristics to the concerned parameters. The hypothetical simulations mentioned may be more successful in enhancing thermal extrusion mechanisms and solar energy structures. The numerical results regarding flow, thermal field, solutal field and concentration of microorganisms are revealed for growing values of interesting parameters. Furthermore, it is inspected that velocity field dwindles with enlarged variation of Maxwell fluid parameter. It is analyzed that radial velocity of Maxwell nanofluid reduces for larger magnitude of mixed convection parameter. Additionally, temperature profile of species upsurges for larger values of thermal stratification Biot number. Moreover, it is inspected that concentration of species decline for higher estimation of Lewis number while enhanced for activation energy parameter. Microorganisms concentration field of Maxwell nanofluid is detected to be an declining function of Peclet number and bioconvection Lewis number. Angorgeous concurrence is obtained when our accomplished numerical results are compared with an already existed magnitudes in limiting condition; hence dependable results are being eliminated.

Convective nonlinear thermally developed flow of thixotropic nanoliquid configured by Riga surface with gyrotactic microorganism and activation energy: A bio-technology and thermal extrusion model

The thermal performances of base materials with thermal radiation, variable heat transportation features and activation energy are quite progressive which allow many industrial, engineering and technological applications. The scientists are still focusing to discover the cheap and friendly environment energy resources. On this end, the utilization of nanoparticles as a energy resource is intended much attention of researcher in recent decade. Moreover, the bioconvection of nano-materials is also a fundamental approach to improve the nanoparticles stability and many bio-technology applications like enzymes, petroleum engineering application, bio-fuels, bio-sensors and many more. Present analysis aim to discover the complex rheological characteristics of thixotropic nanofluid in presence of gyrotactic microorganisms over a Riga surface. The most fascinating features of nonlinear thermal radiation and activation energy are also carried out to improve the heat and mass transportation process. The formulated flow problem is preceded by using convective Nield boundary conditions. After successfully attaining the dimensionless form of formulated set of flow equations, a famous shooting numerical scheme is followed with appliances of MATLAB computational software. The involved flow parameters significance is graphically underline with well justified physical consequences. All physical quantities determining the heat, mass and microorganisms transportations are comprehensively studied via graphs and tables. The key observations revealed from this novel numerical continuation lead to many thermal engineering and solar energy systems applications, energy resources and consumptions, enzymes, bio-sensors and bio-technology.

Effect of Pulse Current and Pre-annealing on Thermal Extrusion of Cu in Through-Silicon via (TSV).

Thermal stress induced by annealing the Cu filling of through-silicon vias (TSVs) requires further investigation as it can inhibit the performance of semiconductor devices. This study reports the filling behavior of TSVs prepared using direct current and pulse current Cu electrodeposition with and without pre-annealing. The thermal extrusion of Cu inside the TSVs was studied by observing the extrusion behavior after annealing and the changes in grain orientation using scanning electron microscopy and electron backscatter diffraction. The bottom-up filling ratio achieved by the direct current approach decreased because the current was used both to fill the TSV and to grow bump defects on the top surface of the wafer. In contrast, pulse current electrodeposition yielded an improved TSV bottom-up filling ratio and no bump defects, which is attributable to strong suppression and thin diffusion layer. Moreover, Cu deposited with a pulse current exhibited lesser thermal extrusion, which was attributed to the formation of nanotwins and a change in the grain orientation from random to (101). Based on the results, thermal extrusion of the total area of the TSVs could be obtained by pulse current electrodeposition with pre-annealing.

Dinaphthothiepine Bisimide and Its Sulfoxide: Soluble Precursors for Perylene Bisimide.

The synthesis and properties of dinaphtho[1,8-bc:1',8'-ef]thiepine bisimide (DNTBI) and its oxides are described. Their molecular design is conceptually based on the insertion of a sulfur atom into the perylene bisimide (PBI) core. These sulfur-inserted PBI derivatives adopt nonplanar structures, which significantly increases their solubility in common organic solvents. Upon electron injection, light irradiation, or heating, DNTBI and its sulfoxides undergo sulfur extrusion reactions to furnish PBI. The photoinduced and thermal sulfur extrusion reactions proceed almost quantitatively. This unique reactivity enabled the fabrication of a high-performance solution-processed n-type organic field-effect transistor with an electron mobility of up to 0.41 cm2 V-1 s-1.

Activation Energy and Thermal Radiation Aspects in Bioconvection Flow of Rate-Type Nanoparticles Configured by a Stretching/Shrinking Disk

Abstract Recent trends in advanced nanotechnology developed thermal consequences of nanoparticles due to increasing significance in various engineering and thermal extrusion systems. The current continuation analyzes the axisymmetric stagnation point flow of magnetized rate-type nanoparticles configured by a porous stretching/shrinking rotating disk in the presence of motile microorganisms. A famous rate-type polymeric liquid namely Maxwell fluid has been used to examine the rheological consequences. Constitutive expressions based on the Buongiorno nanofluid model are used to examine the thermophoresis and Brownian motion features. With imposing similarity variables proposed by von Karman, the formulated problem is composed into dimensionless form. With the implementation of famous numerical technique bvp4c, the solution of governing flow equations is simulated. Graphical significance for each physical parameter is interpolated with relevant physical aspects. The variation in local Nusselt number, local Sherwood number, and motile density number corresponding to engineering parameters is numerically iterated and expressed in a tabular form. The study revealed that radial direction velocity component decreases by increasing the Deborah number and buoyancy ratio parameter. An enhanced temperature distribution for both stretching and shrinking cases has been noted by increasing the Biot number and thermophoresis parameter. A lower motile microorganisms distributed is noted due to the involvement of motile diffusivity.

A Hybrid Methodology to Extract Decision Rules of Heat and Mass Transfer of the Flow of a Non-Newtonian Nanofluid Towards a Vertical Stretching Surface

In this paper a hybridization of group method analysis, hypergraph Principle and rough set theory is established for extracting a set of rules to investigate heat and mass transfer of mixed convection stagnation point flow of a non-Newtonian nanofluid towards a vertical stretching surface. First, the mathematical model describing the flow is transformed from a set of partial differential equations (PDEs) into non linear ordinary differential equations (ODEs) with the aid of group method analysis. Thereafter, the implicit finite-difference scheme is applied to find the numerical solutions of the nonlinear ODEs and the numerical values are depicted in tabular form. Then the reduction technique based on rough set is applied to find all reducts of the decision tables. Finally, the principle of hypergraph is applied to determine the minimal transversal of reducts and mining a set of generalized rules to predict the value of local Nusselt number and local skin-friction coefficient. The results show that the proposed method can effectively predict these values with high accuracy and may be valuable in many engineering applications like power production, thermal extrusion systems and microelectronics.