scholarly journals Influence of Reactor Pressure on the Primary Jet Breakup of High-Viscosity Fuels: Basic Research for Simulation-Assisted Design of Low-Grade Fuel Burner

2018 ◽  
Author(s):  
Thomas Müller ◽  
Kathrin Kadel ◽  
Peter Habisreuther ◽  
Dimosthenis Trimis ◽  
Nikolaos Zarzalis ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Research Work ◽  
Basic Research ◽  
High Viscosity ◽  
Low Grade ◽  
Breakup Length ◽  
System Pressure ◽  
Wide Range ◽  
Primary Breakup ◽  
Characteristic Features

Detail investigations on the primary breakup of high-viscosity liquids using external-mixing twin-fluid nozzles at increased system pressure are scarce. Therefore, the research work of the present study is focused on the investigation of pressure influence (1 - 11 bar (abs)) on the primary breakup by numerical simulation based on a previously studied nozzle [Müller et al., ASME Turbo Expo 2016, GT2016-56371]. The pressure influence was investigated for two liquids applying a wide range of viscosities (100 mPa s; 400 mPa s) and two atomizing air velocities (58 m/s; 74 m/s). To describe the disintegration process of the fluids, characteristic features like liquid jet morphology, breakup length and breakup frequency were evaluated. The primary breakup was investigated using the open source CFD software OpenFOAM. To gather the morphology of the primary breakup and the flow field characteristics compressible large eddy simulations (LES) were performed and the movement of the gas-liquid interface was captured by means of the Volume of Fluid-Method (VOF). The conducted simulations showed good agreement with experimental results with respect to the characteristic features (e.g. morphology and breakup length) and revealed a decrease of the breakup length with increasing ambient pressure for a constant liquid mass flow and atomizing air velocity. Moreover, those findings will contribute to a better understanding of the physics of the breakup of high-viscosity liquid jets and as well to create an experimentally validated CFD based tool for future burner development and optimization.

scholarly journals Simulation of the Primary Jet Breakup of Non-Newtonian Fuels: Basic Research for Simulation-Assisted Design of Low-Grade Fuel Burner

2018 ◽  
Author(s):  
Thomas Müller ◽  
Kathrin Kadel ◽  
Peter Habisreuther ◽  
Dimosthenis Trimis ◽  
Nikolaos Zarzalis ◽  
...  
Keyword(s):  
Surface Tension ◽  
Research Work ◽  
High Viscosity ◽  
Spray Angle ◽  
Low Grade ◽  
Breakup Length ◽  
Third Phase ◽  
Jet Breakup ◽  
Primary Breakup ◽  
Characteristic Features

The research work of the present study is focused on the numerical simulation of primary breakup of high-viscosity non-Newtonian fluids. For the experimental investigation of fluid properties such as viscosity, surface tension and flow behaviour on the jet breakup an external mixing twin-fluid nozzle is used, as investigated in a previous study [Müller et al., ASME Turbo Expo 2016, GT2016-56371]. To describe the disintegration process of the fluids, characteristic features like liquid jet morphology, breakup length, breakup frequency and spray angle are evaluated. Furthermore, the primary breakup of slurries is simulated without discretizing the particles as a third phase, which heavily reduced the computational effort. Instead, the physical properties (density, viscosity) of the liquid phase take the influence of the particles into account. The primary breakup was investigated using the open source CFD software OpenFOAM. To gather the morphology of the primary breakup and the flow field characteristics compressible large eddy simulations (LES) were performed and the movement of the gas-liquid interface was captured by means of the Volume of Fluid-Method (VOF). The conducted simulations showed good agreement with experimental results with respect to the characteristic features (e.g. breakup length) and the significant influence of viscosity and surface tension on the primary breakup. It is reasonably justified that the used OpenFOAM code and VOF is sufficient to simulate the primary breakup of particle laden liquids without discretizing particles as a third phase. Moreover, those findings contribute to a better understanding of the physics responsible of the breakup of high-viscosity liquid jets and as well to create an experimentally validated CFD based tool for future burner development and optimization.

Influence of Nozzle Design Upon the Primary Jet Breakup of High-Viscosity Fuels for Entrained Flow Gasification

2017 ◽  
Author(s):  
Thomas Müller ◽  
Alexa Dullenkopf ◽  
Peter Habisreuther ◽  
Nikolaos Zarzalis ◽  
Alexander Sänger ◽  
...  
Keyword(s):  
Research Work ◽  
Flux Ratio ◽  
Liquid Structure ◽  
High Viscosity ◽  
Design Parameters ◽  
Liquid Jets ◽  
Jet Breakup ◽  
Internal Mixing ◽  
Primary Breakup ◽  
Entrained Flow Gasification

The research work of the present study is focused on the influence of design parameters of twin-fluid nozzles used for the atomization of high-viscosity fuels with respect to the primary breakup of the liquid jet. Two external mixing twin-fluid nozzles, which have already been investigated in previous studies [1, 2], were chosen as basic design. Based on the previous findings the web thickness between fuel and oxidizer supply was varied. In addition both designs were extended by a channel for internal mixing of gas and liquid with a length to diameter ratio of one. Moreover one of the basic nozzles was scaled by decrease of the effective areas in a way that momentum flux ratio as well as gas to liquid mass flow ratio was kept constant. The newly designed atomizers were subsequently investigated with regard to the influence of the changes upon the primary jet breakup using CFD simulations. The numerical simulations were conducted by means of the open source package OpenFOAM. The Volume of Fluid method was used for the determination of the gas-liquid interface. These simulations were then compared with experimentally validated simulations of the basic nozzle designs with regard to the breakup morphology of the jet and the mode of the primary surface instability. In addition, the liquid structure was examined by comparison of breakup length and frequency. The results of these simulations showed that small changes in the atomizer design heavily influence the primary breakup, which in turn influences the overall performance of the atomizer (e.g. SMD). Moreover, these findings will contribute to a better understanding of the physics of the breakup of high-viscosity liquid jets and as well to create an experimentally validated CFD based tool for future burner development and optimization.

Single Point Incremental Forming of Large Sheet Metal Components

2019 ◽  
Author(s):  
Frank Schieck ◽  
Reinhard Mauermann ◽  
Dieter Weise ◽  
Matthias Demmler
Keyword(s):  
Sheet Metal ◽  
Large Scale ◽  
Incremental Forming ◽  
Single Point ◽  
Research Work ◽  
Basic Research ◽  
Good Alternative ◽  
Batch Size ◽  
Simulation And Optimization ◽  
Wide Range

Abstract The production of complex, large-scale cladding parts made of metal in small quantities for a wide range of applications in architecture, power generation, shipbuilding, but also rail vehicle construction, mobile work machines and, last but not least, automotive sector is a major challenge in terms of principled manufacturability, but also in terms of manufacturing costs. Appropriate components are often produced in small quantities by hand, whereby the reproducibility and achievable quality depend largely on the experience and craftsmanship of the employer. The incremental forming using CNC-controlled machine tools or robots offers a good alternative for an efficient and reproducible production of sheet metal components with batch size one. There are already a large number of research work, studies and examples of applications worldwide regarding principled incremental forming strategies, process layout, FE simulation and optimization strategies. The Fraunhofer IWU works with the claim of applied research, that is, to transfer results from basic research into an industrial application. This also applies to the field of incremental sheet metal forming. Especially in the area of large-scale, 3-dimensional components, there is a very great need on the part of the industry. The paper provides an overview of current research results in the field of incremental forming of industrially relevant large-scale structures up to dimensions of approximately 4 × 2 meters, which are carried out in the single point process on a modified large milling machine. The topic of shape storage (molds), flexible clamping frames and heating equipment for temperature-supporting incremental forming of light metals is also addressed. The outlook identifies application and development potential aimed at both the further development of the technology and the associated equipment technology.

Justification of the need to improve the legal, regulatory and methodological framework for the spread of parasitic infections in the provision of medical care

2020 ◽  
Vol 99 (5) ◽  
pp. 493-497
Author(s):  
M. M. Aslanova ◽  
T. V. Gololobova ◽  
K. Yu. Kuznetsova ◽  
Tamari R. Maniya ◽  
D. V. Rakitina ◽  
...  
Keyword(s):  
Medical Care ◽  
Research Work ◽  
Hospital Environment ◽  
Parasitic Infections ◽  
Infusion Therapy ◽  
Methodological Framework ◽  
Production Environment ◽  
Medical Institutions ◽  
Medical Network ◽  
Wide Range

Introduction. The purpose of our work was to justify the need to improve the legislative, regulatory and methodological framework and preventative measures in relation to the spread of parasitic infections in the provision of medical care. There is a wide range of pathogens of parasitic infestations that are transmitted to humans through various medical manipulations and interventions carried out in various medical institutions. Contaminated care items and furnishings, medical instruments and equipment, solutions for infusion therapy, medical personnel’s clothing and hands, reusable medical products, drinking water, bedding, suture and dressing materials can serve as a major factor in the spread of parasitic infections in the provision of medical care. Purpose of research is the study of the structure and SMP of parasitic origin, circulating on the objects of the production environment in multi-profile medical and preventive institutions of stationary type in order to prevent the occurrence of their spread within medical institutions. Material and methods. The material for the study was flushes taken from the production environment in 3 multi-profile treatment and prevention institutions of inpatient type: a multi-specialty hospital, a maternity hospital and a hospital specializing in the treatment of patients with intestinal diseases for the eggs of worms and cysts of pathogenic protozoa. Results. During the 2-year monitoring of medical preventive institutions, a landscape of parasitic contamination was found to be obtained from the flushes taken from the production environment objects in the premises surveyed as part of the research work. Discussions. In the course of research, the risk of developing ISMP of parasitic origin was found to be determined by the degree of epidemiological safety of the hospital environment, the number and invasiveness of treatment and diagnostic manipulations and various medical technologies. Conclusion. It is necessary to conduct an expert assessment of regulatory and methodological documents in the field of epidemiological surveillance and sanitary and hygienic measures for the prevention of medical aid related infections of parasitic origin, to optimize the regulatory and methodological base, to develop a number of preventive measures aimed at stopping the spread of parasitic infections in the medical network.

Development and Evaluation of Sustained Release Lipid Nanocarriers for Curcumin

2020 ◽  
Vol 5 (3) ◽  
pp. 224-235
Author(s):  
Harshal A. Pawar ◽  
Bhagyashree D. Bhangale
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Drug Delivery Systems ◽  
Biological Activities ◽  
Curcuma Longa ◽  
Research Work ◽  
Elimination Rate ◽  
Delivery Systems ◽  
Physicochemical Stability ◽  
Wide Range

Background: Lipid based excipients have increased acceptance nowadays in the development of novel drug delivery systems in order to improve their pharmacokinetic profiles. Drugs encapsulated in lipids have enhanced stability due to the protection they experience in the lipid core of these nano-formulations. Phytosomes are newly discovered drug delivery systems and novel botanical formulation to produce lipophilic molecular complex which imparts stability, increases absorption and bioavailability of phytoconstituent. Curcumin, obtained from turmeric (Curcuma longa), has a wide range of biological activities. The poor solubility and wettability of curcumin are responsible for poor dissolution and this, in turn, results in poor bioavailability. To overcome these limitations, the curcumin-loaded nano phytosomes were developed to improve its physicochemical stability and bioavailability. Objective: The objective of the present research work was to develop nano-phytosomes of curcumin to improve its physicochemical stability and bioavailability. Methods: Curcumin-loaded nano phytosomes were prepared by using phospholipid Phospholipon 90 H using a modified solvent evaporation method. The developed curcumin nano phytosomes were evaluated by particle size analyzer and differential scanning calorimetry (DSC). Results: Results indicated that phytosomes prepared using curcumin and lipid in the ratio of 1:2 show good entrapment efficiency. The obtained curcumin phytosomes were spherical in shape with a size less than 100 nm. The prepared nano phytosomal formulation of curcumin showed promising potential as an antioxidant. Conclusion: The phytosomal complex showed sustained release of curcumin from vesicles. The sustained release of curcumin from phytosome may improve its absorption and lowers the elimination rate with an increase in bioavailability.

ESRC Review

2020 ◽  
pp. 657-698
Author(s):  
Simeon J. Yates ◽  
Jordana Blejmar
Keyword(s):  
Social Research ◽  
Social Science Research ◽  
Research Work ◽  
Science Research ◽  
Wide Range ◽  
The Us ◽  
Levels Of Automation ◽  
The Uk ◽  
Technological World ◽  
Ways Of Being

Two workshops were part of the final steps in the Economic and Social Research Council (ESRC) commissioned Ways of Being in a Digital Age project that is the basis for this Handbook. The ESRC project team coordinated one with the UK Defence Science and Technology Laboratory (ESRC-DSTL) Workshop, “The automation of future roles”; and one with the US National Science Foundation (ESRC-NSF) Workshop, “Changing work, changing lives in the new technological world.” Both workshops sought to explore the key future social science research questions arising for ever greater levels of automation, use of artificial intelligence, and the augmentation of human activity. Participants represented a wide range of disciplinary, professional, government, and nonprofit expertise. This chapter summarizes the separate and then integrated results. First, it summarizes the central social and economic context, the method and project context, and some basic definitional issues. It then identifies 11 priority areas needing further research work that emerged from the intense interactions, discussions, debates, clustering analyses, and integration activities during and after the two workshops. Throughout, it summarizes how subcategories of issues within each cluster relate to central issues (e.g., from users to global to methods) and levels of impacts (from wider social to community and organizational to individual experiences and understandings). Subsections briefly describe each of these 11 areas and their cross-cutting issues and levels. Finally, it provides a detailed Appendix of all the areas, subareas, and their specific questions.

scholarly journals Role of Insulin in Health and Disease: An Update

2021 ◽  
Vol 22 (12) ◽  
pp. 6403
Author(s):  
Md Saidur Rahman ◽  
Khandkar Shaharina Hossain ◽  
Sharnali Das ◽  
Sushmita Kundu ◽  
Elikanah Olusayo Adegoke ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
Basic Research ◽  
Future Research ◽  
Protective Effects ◽  
Glucose Levels ◽  
Physiological Processes ◽  
Blood Glucose Levels ◽  
Wide Range ◽  
Health And Disease

Insulin is a polypeptide hormone mainly secreted by β cells in the islets of Langerhans of the pancreas. The hormone potentially coordinates with glucagon to modulate blood glucose levels; insulin acts via an anabolic pathway, while glucagon performs catabolic functions. Insulin regulates glucose levels in the bloodstream and induces glucose storage in the liver, muscles, and adipose tissue, resulting in overall weight gain. The modulation of a wide range of physiological processes by insulin makes its synthesis and levels critical in the onset and progression of several chronic diseases. Although clinical and basic research has made significant progress in understanding the role of insulin in several pathophysiological processes, many aspects of these functions have yet to be elucidated. This review provides an update on insulin secretion and regulation, and its physiological roles and functions in different organs and cells, and implications to overall health. We cast light on recent advances in insulin-signaling targeted therapies, the protective effects of insulin signaling activators against disease, and recommendations and directions for future research.

scholarly journals Characterization of Polysaccharidic Associations for Cosmetic Use: Rheology and Texture Analysis

Cosmetics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 62
Author(s):  
Giovanni Tafuro ◽  
Alessia Costantini ◽  
Giovanni Baratto ◽  
Stefano Francescato ◽  
Laura Busata ◽  
...  
Keyword(s):  
Raw Materials ◽  
Immersion Test ◽  
High Viscosity ◽  
Natural Polymers ◽  
Public Attention ◽  
First Choice ◽  
Wide Range ◽  
Textural Parameters ◽  
Complementary Techniques

As public attention on sustainability is increasing, the use of polysaccharides as rheological modifiers in skin-care products is becoming the first choice. Polysaccharide associations can be used to increase the spreading properties of products and to optimize their sensorial profile. Since the choice of natural raw materials for cosmetics is wide, instrumental methodologies are useful for formulators to easily characterize the materials and to create mixtures with specific applicative properties. In this work, we performed rheological and texture analyses on samples formulated with binary and ternary associations of polysaccharides to investigate their structural and mechanical features as a function of the concentration ratios. The rheological measurements were conducted under continuous and oscillatory flow conditions using a rotational rheometer. An immersion/de-immersion test conducted with a texture analyzer allowed us to measure some textural parameters. Sclerotium gum and iota-carrageenan imparted high viscosity, elasticity, and firmness in the system; carob gum and pectin influenced the viscoelastic properties and determined high adhesiveness and cohesiveness. The results indicated that these natural polymers combined in appropriate ratios can provide a wide range of different textures and that the use of these two complementary techniques represents a valid pre-screening tool for the formulation of green products.

Development and characterization of electrospun curcumin-loaded antimicrobial nanofibrous membranes

2020 ◽  
pp. 004051752092551
Author(s):  
Javeed A Awan ◽  
Saif Ur Rehman ◽  
Muhammad Kashif Bangash ◽  
Fiaz Hussain ◽  
Jean-Noël Jaubert
Keyword(s):  
Biological Activities ◽  
Research Work ◽  
Medical Applications ◽  
Electrospinning Technique ◽  
Naturally Occurring ◽  
Wide Range ◽  
Nanofibrous Membranes ◽  
Antimicrobial Barrier ◽  
Anti Hiv

Curcumin is a naturally occurring hydrophobic polyphenol compound. It exhibits a wide range of biological activities such as antibacterial, anti-inflammatory, anti-carcinogenic, antifungal, anti-HIV, and antimicrobial activity. In this research work, antimicrobial curcumin nanofibrous membranes are produce by an electrospinning technique using the Eudragit RS 100 (C19H34ClNO6) polymer solution enriched with curcumin. The morphology and chemistry of the membrane are analyzed using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Kirby Bauer disk diffusion tests are carried out to examine the antibacterial effectiveness of the membrane. Experimental results show that the nanofibers produced are of uniform thickness morphology and curcumin is successfully incorporated into the nanofibrous mat, while no chemical bonding was observed between curcumin and the polymer. The antimicrobial curcumin nanofibrous membranes can be effectively applied as antimicrobial barrier in a wide variety of medical applications such as wound healing, scaffolds, and tissue engineering.

Fuel Droplet Evaporation in a Supercritical Environment

2002 ◽  
Vol 124 (4) ◽  
pp. 762-770 ◽  
Author(s):  
G. S. Zhu ◽  
S. K. Aggarwal
Keyword(s):  
Experimental Data ◽  
Phase Equilibrium ◽  
Ambient Pressure ◽  
Droplet Surface ◽  
Fuel Vapor ◽  
Phase Solubility ◽  
Liquid Density ◽  
Ambient Temperatures ◽  
Droplet Vaporization ◽  
Wide Range

This paper reports a numerical investigation of the transcritical droplet vaporization phenomena. The simulation is based on the time-dependent conservation equations for liquid and gas phases, pressure-dependent variable thermophysical properties, and a detailed treatment of liquid-vapor phase equilibrium at the droplet surface. The numerical solution of the two-phase equations employs an arbitrary Eulerian-Lagrangian, explicit-implicit method with a dynamically adaptive mesh. Three different equations of state (EOS), namely the Redlich-Kwong (RK), the Peng-Robinson (PR), and Soave-Redlich-Kwong (SRK) EOS, are employed to represent phase equilibrium at the droplet surface. In addition, two different methods are used to determine the liquid density. Results indicate that the predictions of RK-EOS are significantly different from those obtained by using the RK-EOS and SRK-EOS. For the phase-equilibrium of n-heptane-nitrogen system, the RK-EOS predicts higher liquid-phase solubility of nitrogen, higher fuel vapor concentration, lower critical-mixing-state temperature, and lower enthalpy of vaporization. As a consequence, it significantly overpredicts droplet vaporization rates, and underpredicts droplet lifetimes compared to those predicted by PR and SRK-EOS. In contrast, predictions using the PR-EOS and SRK-EOS show excellent agreement with each other and with experimental data over a wide range of conditions. A detailed investigation of the transcritical droplet vaporization phenomena indicates that at low to moderate ambient temperatures, the droplet lifetime first increases and then decreases as the ambient pressure is increased. At high ambient temperatures, however, the droplet lifetime decreases monotonically with pressure. This behavior is in accord with the reported experimental data.

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