bluuebunny/crossref_metadata_2025 huggingface dataset:
Different Methodologies for Improving Solubility and Bioavailability
Authors: Verma Ravinder , Kaushik Deepak , Kaushik Ritu , Singh Vandana
Published: July 2021

Drug delivery through the oral route is perfect for both solid and liquid
dosage forms. Notwithstanding numerous favorable circumstances, the improvement of
the oral delivery route still speaks to an excellent test attributable to interesting curious
physicochemical characteristics of lipophilic drug compounds and physiological
barriers, such as gastrointestinal unsteadiness, pre-systemic metabolism and efflux
pump. Upon oral intake, lipophilic drug in a dosage form is effortlessly taken by
patients, passes the GIT via a tremendously versatile environment. Factors affecting
solubilization are the size of particle, temperature, pressure, molecular size, nature of
solute and solvent, polarity and polymorphs. Ways of enhancing oral bioavailability
includeboth chemical modifications and formulation modifications. The chemical
modification includes soluble pro-drug and salt formation. While formulation
modification comprises of physical changes like size reduction, crystal habit
modification, complexation (e.g. with β-cyclodextrin), solubilization with co-solvents
or surfactants, drug dispersion with carriers (e.g. eutectic mixture, solid dispersion and
polymeric carriers like micro/nanoemulsions, self-emulsifying drug delivery systems,
liposomes, solid lipid nanoparticles (SLNs) and nanostructured lipid carriers which are
described briefly. A formulation approach is a preferable option to chemical
modification approaches which may prompt the change in chemical structure and may
have an impact on the pharmacological action. Particle size reduction is classified into
two categories - mechanical micronization and engineered particle size control.
Mechanical micronization includes jet milling, ball milling, high-pressure
homogenization. Engineered particle size control includes the cryogenic method, spray
freezing onto cryogenic fluids, spray freezing into cryogenic liquids, spray freezing
into vapor over liquid, ultra-rapid freezing and cryogenic spray processes. Crystal
engineering includes nanocrystals, solid dispersion, co-crystal formation,
sonocrystallization, liquisolid technique, self-microemulsifying drug delivery systems
and inclusion complex which are discussed in detail. This chapter highlights various
methods for solubility enhancements with their merits and demerits.
In Vitro Digestion Models and Pharmacokinetic Aspects of SMEDDS
Authors: Kaushik Deepak , Verma Ravinder
Published: July 2021

In vitro models evaluate lipid-based drug delivery systems for enhancing
solubilization and discharge of the drug. After ingestion, the food particles experience
different physical and chemical changes that prompt their fragmentation into little
pieces and change into less complex atomic groups that can be effortlessly absorbed
into the blood. The dynamic mono and multi-compartmental models have become
more advanced with in vivo information input. The Dynamic Gastric Model (DGM) has
two sections: One is the body and the other is the antrum of the gastric. Up until now,
TNO gastro-Intestinal Model-1(TIM-1) is considered to mimic the closest reproduction
of the energy and flow of human retention. Pancreatic lipase, bile salts, phospholipids
and calcium ions are involved in the intestinal lipolysis. The intestinal lipolysis is
typically assessed by the rate and degree of free unsaturated fats discharged due to the
activity of P-LIP. These can be estimated utilizing diverse strategies such as
colorimetric enzymatic test, gas chromatography and pH-stat titration. The various in
vivo pharmacokinetic aspects of LBFs are formulation and solubilization, dispersibility,
dilution and effect on pharmacokinetics that have been described in this chapter. Other
pharmacokinetic parameters including assimilation and bioavailability improvement,
the impact of excipient choice on bioavailability, lymphatic transport and food effect
reduction have been summarized. This chapter highlights the various in vitro digestion
models and pharmacokinetic aspects of LBFs.
PENGARUH APLIKASI BAKTERI PELARUT FOSFAT DAN PUPUK ANORGANIK FOSFAT TERHADAP POPULASI BAKTERI PELARUT FOSFAT, P-TERSEDIA, DAN HASIL TANAMAN JAGUNG PADA ALFISOL
Authors: Lovitna Gertruda , Nuraini Yulia , Istiqomah Nurul
Published: July 2021

Fulfilment of nutrients for plants can be maximized when fertilization, but the application of inorganic fertilizers can cause damage to the soil if the dosage is excessive. The utilization of phosphate solubilizing bacteria is an effort to increase the efficiency of phosphate fertilization that can extract phosphate from an insoluble form that becomes available. This study aimed to obtain a combination of inorganic fertilization doses (SP-36 and NPK) and the application of biological fertilizers that utilize phosphate solubilizing bacteria (PSB) to increase the population of phosphate solubilizing bacteria and P-available in the soil, as well as corn crop yields. This study used a randomized block design with nine treatments and three replications. The result showed that the application of PSB and inorganic phosphate fertilizer shows a significant effect on the population of PSB, P-available, plant height, stover dry weight, cob weight with husk and cob weight without husk, but didn’t show a significant effect on 100 seeds weight and number of plant leaves. Based on the correlation analysis, the results show a positive correlation between soil chemical properties, P-available, and corn yield.
PENGARUH ABU TERBANG BATUBARA TERHADAP SIFAT KIMIA TANAH DAN SERAPAN TIMBAL (Pb) OLEH TANAMAN AKAR WANGI (Vetiveria zizanioides L.)
Authors: Nugroho Benediktus Lucky Aditya , Lestari Nina Dwi
Published: July 2021

Coal fly ash is a soil amendment that can be used to improve soil productivity because coal fly ash contains essential nutrients needed by plants. However, coal fly ash also contains heavy metals. This study was at a time to explore the effect of coal fly ash on soil chemical properties and lead uptake by vetiver plant (Vetiveria zizanioides L.). Treatments tested were applications of six proportion levels (0, 2.5, 5., 10, 15, and 30% by weight). The seven treatments were arranged in a completely randomized design with three replicates. The result showed that the coal fly ash had a significant effect on soil pH, total-P, total-N, total-K and Pb. The value of the Pb translocation factor from the roots to the shoot of the vetiver plant was relatively low, so that the vetiver plant was not suitable for use in phytoextraction of Pb from Pb-contaminated soil.
“That city, that self”: Tracing a Historical Trajectory of the City Writer
Authors: Hart Ceilidh
Published: July 2021

This article traces a historical trajectory of the city poet in Canada—a writer whose “street-level perspective” defines their methods and shapes their authorial personae—from the nineteenth-century through to the twenty-first. It first provides a brief exploration of some of the literature published in the Toronto Evening Telegram newspaper in the 1880s and 1890s to consider the origins of a literary tradition and an authorial persona rooted in the city. This part of the article uses the example of Robert Kirkland Kernighan to show the way early writers exploited the opportunity provided by city newspapers and the city itself to map and define themselves in artistic and professional terms. The article goes on to consider the work of contemporary city writers like Bren Simmers, who continue mapping themselves onto the street in sometimes deeply personal and increasingly unsettled ways. At base, the article argues that by extending critical discussions of urban writing back to its nineteenth-century roots, we can better understand how the city works as a unique marketplace for literature and a unique cultural economy through which literature circulates, but also as a unique context for the creation of authorial identity.
William Edward Daniel Ross’s Transformation into a Popular Fiction Novelist, 1962-1967
Authors: Friskney Janet B.
Published: July 2021

William Edward Daniel Ross transformed himself into a popular fiction novelist in mid-life; the years between 1962 and 1967 witnessing his authorial advance from apprentice to journeyman. During this period, he produced at least 85 original novels, which appeared in the United States or the United Kingdom in hardback, paperback, or digest format. By 1966, Ross’s rapid production identified him as a “literary factory” within the trade. As a “professional writer,” he responded to the market needs of publishers, which led him to produce novels in multiple genres, including mysteries, westerns, nurse romances, and gothics. The majority of his novels appeared under pseudonyms, most of them feminine; as Ross recognised, this circumstance obscured his claims to authorship, leading to his early designation as “Canada’s best-known unknown author.”
   A substantial collection of Ross’s professional papers held at Boston University represents an invaluable resource into this author’s early years as a novelist, and into the trans-Atlantic popular fiction market for which he wrote. In combination with newspaper and magazine articles episodically published about him, this resource reveals an author who, between 1962 and 1967, established himself with publishers as a reliable creator of popular fiction. Ross brokered key business relationships with several hardback publishers producing popular fiction for the commercial lending libraries, as well as half a dozen paperback firms. Ross’s remarkable level of production relied on key “support personnel”: his wife Marilyn Ross facilitated his writing daily while New York-based literary agents Robert Mills and Donald MacCampbell offered strategic guidance.
“As Truthful as Our Notion of the Past Can Ever Be”: William Maxwell, His Ancestors, and Alice Munro’s The View from Castle Rock
Authors: Thacker Robert
Published: July 2021

Beginning in the mid-1980s, Alice Munro drew attention in interviews to her rapt admiration for the work of William Maxwell, a writer she has called “my favorite writer in the world.” The two were not close, although they met a few times through their shared association with the New Yorker. In 1988 Munro published an appreciation of Maxwell’s work and, after his death in 2000, agreed to revise it for a tribute volume published in 2004. During those years too, Munro was at work on a family volume she had long contemplated, The View from Castle Rock (2006), one that was inspired in part by and modelled on Maxwell’s Ancestors: A Family History (1971). This article examines the Maxwell-Munro crux as an example of the dynamics of authorship; it is an important example of two compatible writers who, throughout their careers, created narrative rooted in the very stuff of their own experience in place and time—whether seen as fiction, autobiography, or memoir. Each did so in ways that accentuate, for the critic intent on analysing authorship, the play of the past in shaping of any narrative.
“Unembedded, Disappeared”: Marlene NourbeSe Philip’s Hyper/In/Visible Literary Celebrity
Authors: York Lorraine
Published: July 2021

In her essays, Marlene NourbeSe Philip has been forthcoming about being “an unembedded, disappeared poet and writer in Canada” whose contributions to cultural life have been systematically obstructed, partly because of her public activism on behalf of Black communities. Her visibility is an oxymoronic, bedeviling combination of disappearance and unchosen hypervisibility, with the hypervisibility largely brought about by a radical misunderstanding and abjection of her work as a cultural activist. In this article, I examine how the “embedded, disappeared” and yet present, visible, audible literary and activist career of Marlene NourbeSe Philip challenges prevailing conceptions of authorship in Canada. In particular, I think about how and why Philip’s hypervisible invisibility offers a challenge to the regimes of visibility which tend to define literary celebrity. Any account of celebrity visibility needs to recognise the fact that the implications and consequences of visibility do not sit evenly on all public persons, as the theories of Katherine McKittrick, Jenny Burman, Sarah J. Jackson, and Toni Morrison testify. Neither is celebrity visibility the dualistic, either/or proposition so frequently framed by celebrity studies: either a much-desired good (an adoring audience) or a reviled evil, as in instances of notoriety, or in cases of overly intrusive, unwanted public attention. Instead, we need to reckon seriously with the ways visibility may be both systemically denied and reimposed as oppressive hypervisibility, as I argue it is in the celebrity of Marlene NourbeSe Philip and, by extension, in that of many racialised public figures.
Friction welding of ceramics to metals
Authors: Bonte Dries , Derynck Bart , De Baets Patrick , De Waele Wim , Faes Koen
Published: July 2021

This paper discusses the progress in a master thesis about friction welding of ceramics to metals. An existing friction welding machine has to be adapted for the experimental part of this research. The required capabilities of this machine are discussed in this paper. As an introduction, a general explanation about friction welding is given. The results of a literature survey on friction welding of ceramics to metals are discussed. The aim of this survey was to determine the process parameters required to obtain a good weld quality. It became clear that few literature exists on friction welding of these materials and that the cited values for the process parameters vary widely. Based hereon, a range of process parameter values was used to make certain design choices. Because a laboratory machine is aimed at, it has to be able to function at varying settings of the process parameters, including testing at higher rotational speeds. Finally, process windows illustrating sound combinations of friction pressure and specimen diameter are calculated. The design choices entail certain restrictions on the capabilities of the machine. These restrictions define the boundaries of the process window
Interpretation of stress-strain curve in pipeline research
Authors: Wellekens J.B , De Waele Wim , Denys Rudi , Hertele Stijn , Verstraete Matthias
Published: July 2021

For the design of on-shore pipelines installed in areas that are susceptible to ground movements and offshore pipelines, axial stresses above yield must be considered. In such so-called strain-based design,knowledge of the stress-strain behaviour of the pipeline steel and girth welds is highly important. These behaviours are influenced by many factors, including: welding parameters, operation temperature, tensile test specimen geometry and orientation, and microstructure of the steel. This paper focuses on the influence of the tensile test specimen geometry and orientation, for the case of UOE formed pipes. As regards the geometry, it is concluded that the stress-strain diagram is most representative for a flat fullthickness test specimen. As regards the orientation, the yield stress is higher for transversal test specimens, as compared to longitudinally oriented test specimens.
Wear investigation of wet clutch friction material
Authors: Genbrugge Bart , De Baets Patrick , Ost Wouter
Published: July 2021

Wear of friction plates for wet clutch applications can result in a decreasing transmittable torque and the occurrence of vibrations throughout the entire drive chain causing loss of performance and discomfort. The need for a simple wear model exists to predict the lifetime of the clutch and to give an insight in the combined influence of the operational parameters such as pressure and speed. In this paper wear of paper-based friction material is investigated on a simplified SAE#2 test-rig using only one friction plate and one spacer plate. During engagement torque, applied pressure and sliding velocity are continuously monitored. After a set number of engagement cycles the thickness change of the friction plate is measured and surface topography of the spacer plate is registered. Based on Archard’s wear law a specific wear rate is derived.
Traction and wear mechanisms during roll-slip contact
Authors: De Pauw Jan , Van Wittenberghe Jeroen , De Baets Patrick
Published: July 2021

In the transportation industry every vehicle that makes contact with the road and propels itself, is subjected to roll-slip in the wheel-road interface. Therefore a good understanding of this phenomenon is important. This article describes roll-slip contacts in general, with extra attention for the wheel-rail contact which is commonly used. Firstly the contact area and the pressure distribution that occur when a normal load is applied between two bodies is discussed. On this base, the traction mechanisms for static and rolling configurations are shown. Lastly, wear mechanisms and two different wear maps are shown which are very useful and commonly used in wear mapping of roll-slip contacts. A good agreement with field measurements can be obtained.
High conductive graphite additives for magnesium catalyzed cast PA6 polymer matrix
Authors: Ando Matyas , Kalacska Gabor , Czigany T.
Published: July 2021

At this article we give a brief review about the additives effects for cast polyamide 6engineering plastics. The natural grade Magnesium catalyzed polyamide 6 has unique mechanicalproperties. Our target is to keep the mechanical and tribological properties with the development ofantistatic and ESD composite version. High conductive very effective to improve the electricalconductivity of magnezium catalized cast PA 6. Only few amount, 0,5% can result good antistaticproperty for the base matrix. Over 3% of additive the surface resistance of the material – performing107 Ω - can reach the ESD (Electrostatic Dissipative) category.
Weldability of micro-alloyed high-strength pipeline steels using a new friction welding variant
Authors: Faes Koen , De Baets Patrick , Dhooge Alfred , De Waele Wim , Denys Rudi , Van Der Donckt E. , Delbaere D.
Published: July 2021

An innovative welding method for fully automatic joining of pipelines has been developed. Theproposed welding procedure is a variant of the conventional friction welding process. A rotatingintermediate ring is used to generate heat necessary to realise the weld. The working principles of thewelding process are described. The weldability of the micro-alloyed high-strength pipeline steel API-5L X65is experimentally investigated. It was found that the new welding process is suitable for joining this material.When welding with a sufficiently low heat input, a high weld quality is obtained. Under these circumstancesthe weld strength, ductility and impact toughness are high and fulfil the requirements of the commonly usedstandard EN 12732 for joining pipes.
The effect of the different cutting tools on the micro-geometrical surface of engineering plastics
Authors: Farkas G. , Kalacska Gabor
Published: July 2021

We would like to present in this article the results of the microgeometrical study of theengineering polymer surfaces and the applied cutting tools. We compare the effects of differenttechnological parameters (cutting speed, cutting feed, depth of cut) having on the microgeometricalcharacteristics (Ra, Rz) and we summarise the results and conclusions from the practical engineeringlife.
Biomechanical research of Szent István university
Authors: Csizmadia B. , Fekete, Gusztav
Published: July 2021

This paper represents a short summary of the human knee joint modeling. The BiomechanicalTeam of the Szent István University investigates the motion of the human knee in the case of squatting. Inthe analysis of the previously mentioned motion the emphasis is laid on the kinematical properties, which isapproximated by experimental and numerical ways. Primarily the sliding and rolling properties of the humancondyles are examined, especially I in those domains where pure rolling, rolling and sliding jointly, and puresliding may occur. Since only the two extremities are well known in the theoretical and applied mechanics,this paper wishes to furnish further information to the subject. On the other hand, in order to determinespecial additional features the global experimental investigations of the knee are also crucial. These resultscan be essential for further investigations of the phenomena of the combination of rolling and sliding and toshow a new path of creating prosthesis.
Machining the Zirconium-dioxide engineering ceramics
Authors: Fledrich G.
Published: July 2021

In place of brittle ceramics used so far have appeared up-to-date so called tough ceramicmaterials resisting better against mechanical effects [2]. Such material is the zirconium-dioxide, too.The important advantage of hard-turning is the applicability of universal tool. Various outlines can beformed by a tool given. Machining ceramics in case of using traditional machining (turning, milling,drilling) requires special technological conditions (tools, machine-tools, technological parameters, etc.)which are developing presently. We would like extending our research work in this course, too.
Analysis of electro-rheological fluid in hydraulic system
Authors: Földi L. , Janosi L.
Published: July 2021

Use of intelligent materials has been a more widespread technology in the last ten years inthe area of research and development of mechatronic equipments. It’s main reason is that someproblems of the utilization needed such a solution, which couldn’t be solved only with new materialsproduced by material texture modification.A claim has come up in the research of the mechatronical systems to develop materials that can getand understand an information from a computer and change their attribution accordingly. Theconnection, what we can establish between the computer and material, sets a limit to the qualitycharacteristics that can be operated by the computer. This transposal can be ensured by effects that’sinduction and abolition rate can be compared or the control is bigger just as the velocity of the changeof a material characteristic. From a control technology viewpoint using electric or magnetic field is themost obvious.One group of these materials is electro-reologic (ER) liquids that change their shear strengthaccording to the electric field. The flow qualities of the ER liquids can be continually changed insidecertain borders, with orders of magnitude shorter interval from the previous hydraulic solutions.Making an opportunity by to create faster controlling and regulating systems from the present ones.The main aim of this work is the modification of basic properties of this kind of liquids and specificationof its utilization possibilities in mechatronic systems such as hydraulic control equipments.Mathematical model as well as its numerical solution of a flow control valve (ER valve) as anappropriate element of hydraulic systems has been prepared during this work. Function tests of thisunit have been carried out by computer aided simulation of the above mentioned mathematical model.
Inherent possibilities and limitations of finite element modelling of defective girth welds
Authors: Hertele Stijn , De Waele Wim , Denys Rudi , Verstraete Matthias
Published: July 2021

Welds unavoidably show defects, which can negatively affect the integrity of the entire structureand, worst case, result in a failure. Defects of a considerable size should therefore be detected, assessedand, if necessary, repaired. The assessment of a defect requires a procedure which allows a conservativeestimation of the acceptability of the defect. To develop such procedure, both experimental and numericalresearch is performed. This paper describes the inherent possibilities and limitations of numerical researchthrough finite element modelling, as compared to experimental research. Summarizing all arguments, itbecomes clear that numerical research is a highly powerful tool, but a thorough experimental validation is ofparamount importance. Moreover, some specific weld-related problems are highly difficult to address,namely the presence of stable crack growth and material heterogeneity. More research is needed toachieve a description of these phenomena, under a set of conservative assumptions.
Research of machining forces and technological features of cast PA6, POM C and UHMW-PE HD 1000
Authors: Keresztes Robert , Kalacska Gabor
Published: July 2021

Nowadays parts made of up-to-date engineering plastics are used more and morein mechanical engineering practice. These machine-elements are produced most frequentlyby injection molding or by one cutting process. The injection molding technology are usedgenerally for great number of pieces, in case of serial production while cutting processes arepreferred to piece (unit) or smaller number production.We used lathe and measured the main- and feeding-directional cutting force at differentengineering polymers (cast PA6, POM C and UHMW PE HD 1000). The analysis made canbe well used in practice.
How design quirks and conditions of use conspire to structural failure: a case study
Authors: Ost Wouter , Van Wittenberghe Jeroen , De Baets Patrick
Published: July 2021

Sometimes designers introduce a number of quirks in their design, either due to a preference forcertain technologies or practices or under the influence of the policies in the companies they work for. Whilemost of the time these quirks are harmless, sometimes they can, either in themselves or in combinationwith the conditions in which the design is used lead to failure. In this paper a case is discussed in which adesigner used a quirky solution of lengthening an existing design of a 40ft. freight container to 45ft.. Whilethe design in itself was not fundamentally flawed, it proved to be incompatible to the handling equipmentstill in use at most seaports
Finite element simulation of springback in TRIP 780 advanced high strength steel
Authors: Safaei Mohsen , De Waele Wim , De Baets Patrick
Published: July 2021

This paper discusses the effects of mechanical anisotropy of TRIP 780 advanced high strengthsteel on the springback observed in sheet metal forming. A series of finite element analyses using the Hill’s48 transverse anisotropic yield model and a standard U-shape forming test based on the NUMISHEET’93benchmark has been performed. A comparison of springback angles for different orientation of sheet stripsrelative to the rolling direction is presented. The results show that the amount of springback changes withrespect to the orientation of the test samples
Micro-welding technology platform
Authors: Van Caenegem Nele
Published: July 2021

The BWI (Belgian Welding Institute) works in collaboration with CEWAC (Centre d’études wallonde l’assemblage et du contrôle des matériaux) and MULTITEL, 2 other approved research centers on aproject concerning micro welding and associated quality controls. A platform that groups different microwelding processes and adapted, advanced quality controls has to be build up. The technologies are: microfriction stir welding, micro-plasma, micro-TIG, micro-resistance welding, micro-laser welding, micro-electronbeam welding, digital micro-radiography and micro-control via adapted penetrant inspection. Some of thesetechnologies are already available at CEWAC, others are new. The installation of all the equipment, theexisting and the new machines, is foreseen by July 2010. This platform will be accessible for all companies,to know the technology, to compare different techniques, to ask for the best solution, the best parameterset-up for their application, to make small pre-series, etc…
Evaluation of pipe bending reference stress equations
Authors: Verstraete Matthias , De Waele Wim , Hertele Stijn , Denys R.
Published: July 2021

The use of a Failure Assessment Diagram (FAD) is widespread in the assessment of welddefects. To determine whether a defect is acceptable or not, this requires the calculation of a load ratio anda fracture ratio for the defect under consideration. Nowadays, many formulae are available to calculatethese two quantities and no clear guidance is given on which equation(s) should (not) be used. A partialclarification of this problem is achieved by comparing different reference stress equations. This article isconcerned with such comparison, for the specific case of welded pipes subjected to a bending load. A largeset of historical experimental data has been investigated in which defected pipes were subjected to anincreasing bending force until failure occurred. Two kinds of reference stress equations are considered, fullpipes subjected to a bending load and flat plates subjected to a uniform tension load. From the equationsunder consideration, the flat plate solution of Goodall & Webster and the empirical full pipe equations ofWilloughby and Wilkowski & Eiber describe the pipe failure in the most accurate way
Tribological behaviour and surface quality of polymeric industrial sealing materials
Authors: Zsidai Laszlo , Keresztes Robert
Published: July 2021

Tests presented in our research work as an example give look into the wear and frictionbehaviour of some typical polymer sealing compound (POM, PEEK, PA). The measurementsexamine above all the effect of surface roughness onto the wear and friction behaviour wear incase of optimal loading relations. We have carried out the test in pin-on –disc system. Based onthe test results we have classified the polymers on the basis of wear and friction factors.Keywords polymer tribology, sliding seals, surface roughnes, pin on disc
Characterization and modeling of friction and wear: an overview
Authors: Al-Bender F. , De Moerlooze K.
Published: July 2021

In this age of virtual design, high-performance machines, and precise motion control, the abilityto characterize friction and wear processes and then to model and simulate them, becomes a pertinentissue. This communication gives a condensed overview of the generic characteristics of friction, thereafter,generic models, developed at KULeuven, PMA, are presented and discussed.with Leuven Air Bearings N.V. since Sept. 2010In regard to friction, both sliding and rolling are considered. The characterization concerns (i) therelationship between the friction (traction) force and the state of sliding of the system (displacement,velocity,…), at a given normal load; (ii) the relationship between the coefficient of friction and the normalload.As regards frictional behaviour in function of sliding (rolling) state, the main features are: (i) pre-sliding (prerolling) hysteresis and (ii) gross-sliding (rolling) dynamics. Models are presented that capture those featuresand relate them to the contact characteristics. Comparison with experimental results is also presented forthe main features. Secondly, the dependence of the coefficient of friction on the normal load is identifiedand modelled.Finally, regarding wear simulation, the generic friction model is extended to cater for an asperity populationthat changes during the lifetime of sliding. Based on fatigue considerations, asperities get broken after acertain number of contact cycles, and are replaced by smaller ones. With the aid of this model, we try tocorrelate energy dissipation with wear evolution, and support that by experimental observation.
Tribological behavior of composite-steel on rolling/sliding contacts for various loads
Authors: Ando M. , Sukumaran Jacob
Published: July 2021

Composites have replaced metals in the bearing industry for the exclusive performances from itsproperties were it can accommodate resins, fabrics and additives. Roll-slip is common behaviors inapplication were non-conformal contact exhibits like bearings, rollers and cams. Two elements control thetribological behavior of the material which is the rolling and the sliding element. Composite-steel contactswere tested using a twin-disc setup with open tribo-system to study the influence of load on the frictionalbehavior of the polymer composites. The contacts were tested with four different loads under 20% slip ratiofor a regular interval of time. The curves from the friction force with respect to different loads follows atendency of linear increase in friction force were the rolling resistance is the dominating mechanism. For thegiven condition the macro level investigations shows the absence of transfer layer on the steelcounterparts. The tendency of the friction curve and the micrograph explicitly deliberates the involvement ofabrasion and adhesion in the harder polymer from metal counterpart. The temperature variable is isolatedin case of the above research. The examination of the contact surface reveals the formation of craters onthe junction of polymer and textile.
Improved handling characteristics of off-road vehicles by applying active control of steering wheel torque
Authors: Kis J. , Jánosi L.
Published: July 2021

Driving speed of agricultural mobile machines have been increased in the recent years, raisingserious questions about vehicle handling characteristics considering the high center-of-gravity, multi-massconfiguration and rear-wheel-steering of these vehicles. The next generation of steering systems on offroad vehicles will incorporate a steering column mechatronic subsystem which will generate tactilefeedback for operator. This paper presents our research work to utilize steering wheel torque to improveoff-road vehicle handling characteristics.
Developing small-aircraft service and re-construction of landing-gear leg support
Authors: Lefánti R. , Kalácska Gabor , Oldal I. , Petróczki K.
Published: July 2021

The programs of air-operation and service in the aviation engineering - within this at light-aircraft too - takeplace according to rigorous regulations [6, 7]. There are such machine units and parts which regulation areincomplete, for instance such is the landing-shaft seating. We have developed a new maintenance modelbased on the traditional ones, which offers new information exchange modul for e.g. weak point reconstruction and uses paper based documentation and modern remote maintenance as well. Beside thenew model we have worked out a renewing solution of the often failed landing-gear leg support applyingfield and laboratory test and FEM modelling to fill up as an engineering example for the information modulof the new maintenance model.
Effect of velocity on roll/slip for low and high load conditions in polymer composite
Authors: Sukumaran Jacob , Ando Matyas , Rodriguez Fereira Vanessa , De Baets Patrick
Published: July 2021

In the last decade polymer composites are often used without lubrication on both low and highspeed applications. Some of the application areas are marine, automotive and agriculture used as bearingsand cams where roll-slip is the dominant mechanism. Limited studies are made for composites relatingsuch applications where rolling/sliding condition influences the tribological behavior of the material.Investigating the roll-slip phenomenon for identifying the influence of velocity on frictional behavior canmark a boundary to map the use of composites with respect to its application. Moreover, the design of thematerial can be optimized to match the operating conditions. In the current research the polymer composite(with polyester matrix) has been tested under rolling-sliding condition for two different loads with 61N and210N and with different speeds ranging from 10 rpm to 700 rpm. Ideal conditions in terms of roughness, slipratio, surface temperature and ambient temperature were maintained to reduce the frictional heating. Usinga 20% slip ratio the behavior of the material was observed for the tribological characteristics where the rateof increase of friction force follows a exponential pattern with increasing speeds. Nevertheless, on testingwith high speeds a steady rate of increase in the friction curve was observed. Friction behavior ofcomposites under different speeds is briefed with the microstructural characteristics for low and high loads.
The symmetrical behaviour of carbon nanotubes junctions
Authors: Pataki T.I. , Szakál Z.
Published: July 2021

We have been developing a mathematical model to predict the mechanical behaviour of carbonnanotubes under loads having different types of structures. In this paper we would like to introduce thebehaviour of carbon nanotubes junctions under tensile strain. With an example we display that in astructure the junctions are very important intensifier component. We show the difference between thesymmetrical and non-symmetrical junctions. We give an answer, which junctions are symmetrical andwhich ones are not symmetrical. Under tensile strain the “Y” junctions have different behaviour, if they aresymmetric, or not.
A nice thing about standards
Authors: Verstraeten R. , Jonckheere T. , R. De Meyer , Van Campenhout J.
Published: July 2021

The paper documents the implementation of automated data exchange process as an alternativeto the manual workflow an architect needs to go through if he wants to comply with the EPR and acousticregulations imposed by recent Flemish standards. This application is able to import specific IFC files andinterpret its information. It automatically acquires the information needed and performs the calculations. Theresults of the calculation are then displayed through a user-friendly interface, to enable a designer evaluatehis design and immediately make improvements to his model. This application was tested in a case-studyusing an exemplary BIM model. The overall functionality of the communication process from BIM to theapplication is analysed and the resulting concerns are outlined.
Fatigue damage identification in threaded connection of tubular structures through in-situ modal tests
Authors: Bui Tien Thanh , De Roeck Guido , Van Wittenberghe Jeroen , De Baets Patrick , De Waele Wim
Published: July 2021

The use of threaded connection is a valuable alternative to conventional welding in tubularconstructions, e.g. pipelines, drill pipes and deep water risers. Those applications are normally exposed toenvironmental hazards – wave induced vibrations, temperature changes, etc. – as well as subjected tosevere service conditions. A classical way to determine fatigue strength in many engineering situations is tocalibrate material models by means of ad hoc designed experiments. Unfortunately, it is very difficult in thiscase even under laboratory conditions due to complicated stress and strain states in the contacting taperedhelical thread surfaces of the connection. Therefore, a classical four-point bending fatigue test setup hasbeen built with a real pipe specimen of 3.75 meter long, consisting of two standard API pipes connected bya threaded coupling, under unsymmetric (non-zero average) load control cycles. A complete vibration studyhas been carried out based on input-output modal tests for the entire period of the fatigue experiment. Inputexcitation is due to hammer impact and responses are recorded by accelerometers and by reusabledynamic strain gauges. The measured modal strains from the dynamic strain gauges allow for directcalculation of the modal curvatures, rather than deriving approximately from acceleration information. Bycomparing the measured modal parameters with those of a numerical model of the same structure inundamaged condition, damage detection, localization in the coupling and quantification are possible. Thisstudy leads to the following conclusion of practical use: the recent advancement in modal analysis, i.e. thereference based input-output combined deterministic-stochastic subspace identification, makes it possibleto identify the structural modal properties from in-situ modal tests, which are performed while the fatiguetest is ongoing. In this way the fatigue test is uninterrupted to avoid the problem of stress and straindisturbances happened in un-reversing load cycles test.
Towards better finite element modelling of elastic recovery in sheet metal forming of advanced high strength steel
Authors: Safaei M. , De Waele W.
Published: July 2021

The first part of this study discusses the influence of element type on parameters such asaccuracy of the FE simulation, simulation time and convergence. Guidelines on optimal implementation ofelement types are proposed. It is shown that an inappropriate choice of element type results in difficulties inconvergence of the simulation or gives rise to problems such as shear locking in elements. In the secondpart of this study a series of finite element simulations using the Hill’48 planar anisotropic yield criterion anda standard U-shape forming test based on the NUMISHEET’93 benchmark was performed. Theeffectiveness of different isotropic hardening laws and different contact models is investigated. The mostappropriate hardening and contact definitions are defined from the viewpoint of optimal springbackprediction. Finally, the influence of the orientation of sheet strips relative to the rolling direction onspringback angles is evaluated.
Analytical and computational estimation of patellofemoral forces in the knee under squatting and isometric motion
Authors: Fekete Gusztav , Málnási Csizmadia B. , Wahab M.A. , De Baets Patrick
Published: July 2021

This study presents an intermediate step in prosthesis design, by introducing a newly developedtwo-dimensional mathematical, and a three-dimensional computational knee model. The analytical model isderived from Newton’s law with respect to the equilibrium equations, thus based on theoreticalassumptions, and experimentally obtained parameter. The numeric model is built from an existingprosthesis, involving three parts as patella, femur and tibia, and currently it is under development. Themodels are capable to predict – with their standard deviation – the patellofemoral (numerically tibiofemoralas well) forces in the knee joint during squatting motion. The reason why the squatting is investigated is dueto its relative simplicity and the fact, that during the movement the forces reach extremity in the knee joint.The obtained forces – as a function of flexion angle – are used firstly as fundaments to the knee designmethod, and secondly to extend the results related to the existing isometric kinetics, where one of the newlyobtained functions appears as an essential – and so far missing – input function. Most results arecompared and validated to the ones found in the relevant literature and put into a dimensionless form inorder to have more general meaning.
Design of a (mini) wide plate specimen for strain-based weld integrity assessment
Authors: Hertelé S. , De Waele W. , Denys R. , Verstraete M.
Published: July 2021

Wide plate tension tests are commonly executed to investigate the integrity of defective weldsunder a uniaxial load. The specimen can be flat or curved, depending on the geometry from which it hasbeen extracted (plate or pipe). Despite its usefulness, the design of the (curved) wide plate test is still notstandardized up-to-date. This paper compares two specimen designs with a different length-to-width ratiothrough finite element analysis, using a design-of-experiments approach to account for different influentialfactors. The results reveal significant differences between the interpretation of tests with net sectioncollapse and gross section collapse, promoted by weld strength overmatch. Further, both investigateddesigns tend to provide similar estimates of failure mode, strain capacity and crack driving force. Hence,the shorter specimen is considered an acceptable alternative to the slightly more representative longerspecimen.
Determination of granular assemblies' discrete element material parameters by modelling the standard shear test
Authors: Keppler I. , Csatar A.
Published: July 2021

Soil and agricultural products interact with the tools and equipment used to manipulate and storethem. This interaction causes the load of the tools and of the agricultural product. The practicing engineerhas to know how these types of materials behave so as to be able to examine and control their mechanicalbehaviour. To fulfil this aim we have to find a general model of these materials and apply this to the specificcases. A relatively new model of granular assemblies is the so called discrete element based model. In thismodel we describe the granular assembly as the collection of large number of small rigid bodies, and themodelling process of the assemblies’ behaviour is based on solving the equations of motion of this largenumber of particles directly. The question that arises from the practical use is how we can determine theparameters which affect the interaction between the particles: the coefficient of static- and rolling friction,coefficient of restitution, Young modulus and Poisson’s ratio of a given (in some cases very small) particle.The direct measurement of these quantities is of course impossible for really small particles. We developeda new method based on performing the standard shear test of the given materials and by modelling theshear test using discrete element method. If the discrete element parameters of the numerical model areproperly set, the output data coming from the measurement will be in good agreement with the data comingfrom the discrete element model.
Design of crack arrestors for ultra high grade gas transmission pipelines: material selection, testing and modelling
Authors: Van den Abeele F. , Di Biagio M.
Published: July 2021

One of the major challenges in the design of ultra high grade (X100) gas pipelines is the identification of areliable crack propagation strategy. Recent research results have shown that the newly developed highstrength and large diameter gas pipelines, when operated at severe conditions, may not be able to arrest arunning ductile crack through pipe material properties. Hence, the use of crack arrestors is required in thedesign of safe and reliable pipeline systems.A conventional crack arrestor can be a high toughness pipe insert, or a local joint with higher wall thickness.According to experimental results of full-scale burst tests, composite crack arrestors are one of the mostpromising technologies. Such crack arrestors are made of fibre reinforced plastics which provide the pipewith an additional hoop constraint. In this paper, the material selection, testing and modelling for the designof composite crack arrestors is presented.First, an overview of the most commonly used (integral and non-integral) crack arrestors is given, indicatingthat fibre reinforced devices are one the most promising solutions to arrest running fractures. Then, materialcharacterization of unidirectional fibre glass reinforced epoxy is addressed to measure the orthotropicproperties of this composite material. Traditional mechanical characterization is compared with a nondestructive testing method to measure the elastic constants of the composite material. In the end,micromechanics of fibre reinforced plastics is applied to predict the material properties. The theoreticalpredictions are compared with experimental values.In an accompanying paper, numerical tools to simulate crack initiation, propagation and arrest for this typeof crack arrestors are introduced. The combination of numerical simulation and experimental researchallows deriving design guidelines for composite crack arrestors.
Validation of a wide plate finite element model using digital image correlation
Authors: De Keyser K. , Van Acker F. , Hertelé Stijn , Verstraete Matthias , De Waele Wim , Denys R.
Published: July 2021

To investigate the influence of global plastic deformations on girth weld defect tolerance inpipelines, a parametric finite element model has been developed. This paper provides an experimentalvalidation of the model. It describes the test setup and instrumentation used for the evaluation of plasticstrain fields around a notch in a tension loaded non-welded X65 mini wide plate. LVDT measurements anddigital image correlation (DIC) results are compared to each other and to the results of finite elementsimulations. Whereas some deviation is observed owing to unavoidable experimental uncertainties andlimitations of finite element modelling, the overall correspondence is more than satisfying.