bluuebunny/crossref_metadata_2025 huggingface dataset:
True Noise: Defining Scenes in Toronto’s Underground Music Community
Authors: Kerr Jeremy
Published: April 2021

Underground music refers to genres which are not mass disseminated in the same way as mainstream styles, often due to their abrasive and lo-fi aesthetic. In large cultural centres, such as Toronto, underground music listeners develop their own communities and infrastructure – the framework of musical scenes – and seek out likeminded music fans both locally and virtually. Scholars such as Will Straw, Sarah Cohen and Holly Kruse have all developed theories concerning the development and definition of musical scenes which, while helpful, do not sufficiently examine how scenes are created and interact beyond geographically shared space. To address this gap, I have developed a theory which posits all musical scenes can be placed in one of two categories: local scenes, which are based around a specific locality and the infrastructure available for local scene participants, or super-local scenes, which are not bound by any one locality and can consist of multiple local scenes as well as independent participants. This presentation defines the Toronto underground scene as a super-local scene comprised of several smaller music scenes in the GTA. I will analyze the interactions between these local scenes, as well as with non-local participants, touring international acts, the mass media and the city authorities in order to model the structure of the super-local Toronto underground music scene. I suggest this framework will be useful to other scholars, even those outside of musicology, who are studying similar types of communities.
Mock Research Proposal on Unregistered Syrian Climate Refugees in Jarraheih Camp of Bekaa, Lebanon
Authors: Silverberg Erin
Published: April 2021

Climate change is one of the greatest challenges of the 21st century, displacing a global annual average of 26.4 million people due to climate-related disasters. Currently, over 1.1 million Syrian refugees have fled to Lebanon due to climate-related drought and subsequent war, with 320,000 who remain unregistered by the UNHCR. Unregistered refugees are restricted from accessing services, shelter, and financial means for survival and risk arrest, detention, and deportation by Lebanese authorities for not having proper documentation and paid residency fees. These consequences are felt the most in refugee camps along the Syrian-Lebanese border region such as Bekaa, Lebanon. Despite the presence of humanitarian aid, refugees in camps are left in legal limbo, deprived of accessing the right to have rights. Specifically, for climate refugees, international treaties or future mitigation mechanisms are lacking, exacerbating their vulnerability. Therefore, this research questions the physical and social experiences of unregistered Syrian climate refugees in the Jarrahieh camp, Bekaa, Lebanon. The intention is to determine how these refugees, without official status, are impacted and coping with current federal and international legislative measures. By working with the refugees and key local actors, this research aims to understand how solidary and community organization can be formed within the current legal system to facilitate smoother adaptation and resettlement for climate refugees. Using participatory observation, focus groups, semi-structured interviews, and archival research, the practical outcome is a solidarity group that is established, run, and evaluated by a sample of unregistered Syrian climate refugee men and women aged 18-65.
Caleb Wing and the Ninth Miniature: An Investigation into a Copied Manuscript Leaf and the Bibliophile Community in 19th Century England
Authors: Berry Abigail
Published: April 2021

Buried within the famous Isabella Breviary, on the recto of page 37, there is a depiction of the circumcision of Christ. The miniature depicts Joseph and Mary on their knees, watching the circumcision of Christ being performed by a priest and another unrecognizable religious figure. Saying that this page is unknown to art historical scholarship is an understatement—the circumcision illumination in the breviary has never been referenced in scholarly writing. 

Yet buried in an art collector’s house in the small city of Kingston Ontario, there is a beautifully detailed copy of the basically unknown circumcision leaf from the Isabella Breviary. The copy underwent chemical testing and it was revealed that the leaf was created in the 19th century. How did a copy of this unknown leaf end up in a small Canadian city? Who created this copy, and why? This presentation will explore the history, iconography and provenance of the Kingston Leaf. Although the Kingston Leaf is an almost direct copy of the original leaf in the Isabella Breviary, the small differences between the two pages provide clues that I believe connect the Kingston Leaf to the famous manuscript copier, Caleb Wing. But more importantly, the provenance reveals a community of 19th century English bibliophiles and art dealers, who were thinking about and evaluating medieval art. Their trades and deals surrounding the Kingston Leaf, and the Isabella Breviary, provide insight into the Gothic revival, and the Victorian romanticism of medieval art.
Capturing Conquest: 20th Century Colonial Photography in the Philippine Islands and its 21st Century Musical Legacy
Authors: Dahm Kalila
Published: April 2021

It is a common tool of empire to use racial othering to justify conquest of both land and body. Yet in spite of achieving independence twice, once from Spain in 1898 and again in 1946 from the United States, suggesting the end of colonial discourse, the question remains: why do Filipinas remain hyper-sexualized and fetishized today? The purpose of this project is to examine the tools of empire as a means of justifying an American colonial agenda in the Philippine islands. Particular attention is paid to musical representations and colonial photography to situate the hyper-sexualization, and eventual fetishization, of Filipinas in contemporary American society and 20th century American empire. To date, somewhat limited English literature exists on the topic of 20th century American colonial photography. And yet, sexualized representations of Filipinas are not limited to photography, nor did this view of Filipina bodies, and by extension Filipinas, suddenly stop after independence; problematically suggesting that consequences of empire, including race-based and/or sexual hierarchies, no longer exist. This paper hypothesizes why this imagery remains relevant in the 21st century through an examination of contemporary musical lyrics, suggesting that the hyper-sexualization of Filipinas is rampant in contemporary American society as a product of residual colonial discourse. Then, this paper attempts to retrace the start of American presence in the Philippines at the end of the Spanish-American War of 1898 by examining representations of Filipina bodies as a tool of empire, justifying American imperialism until the mid-20th century, marking the beginning of colonial rhetoric.
Ignorance is Bliss: Memorialising Indigenous History in the United Kingdom
Authors: Fung Emily
Published: April 2021

As Britain strives to take more pride in its history and promote ‘British’ values in its schools, its role in North American Indigenous history has been left off the curriculum, resulting in an education that lacks any awareness of the societies whose land it colonised. After four months of studying Indigenous history and culture for the first time, this final project sought to find a way to memorialise Indigenous people and their culture in one of the countries that was most responsible for their suffering – a country that is now so able to turn a blind eye to events that didn’t occur within its shores. In doing this, this project considered the implications of memorialising events that occurred an ocean away, and the wilful or naïve ignorance of the British public. After considering various forms of memorials, this project focused on designing a memorial garden, serving partly to increase the visibility of Indigenous people to British citizens, and partly to begin educating on aspects of their culture. This resulted in research on plants, wildlife, and symbols important to Indigenous societies, and careful consideration of all features of the garden, proposing a way for Indigenous stories to be told. The final design emphasises the importance of water, nature, and community, and is proposed as a way to begin eroding the ignorance of the British public to events that should be considered part of their history, and the cultures they affected through them.
The choice of excipients to obtain tablets based on the Primula denticulate Smith. Extract by wet granulation
Authors: Shyrko A. Yu. , Vasenda M.M. , Будняк L.I. , Pokotylo O.O.
Published: April 2021

Introduction. Herbal medicines are increasingly being used in the treatment of various diseases. Significant number of resources, high-level availability and the possibility of cultivation have provided high prospects of plant raw materials in the development of new herbal medicines. Primula denticulate Smith. is one of the most interesting medicinal plant raw materials source in modern medicine and pharmacy with the wide spectrum of pharmacotherapeutic action, that is mainly used only in traditional medicine. Thus, nowadays the development of new and effective medicines based on Primula denticulate Smith. in tablet dosage form is the topical task of pharmacy.

The aim of the work. To study the influence of excipients on the pharmaco­technological parameters of tablets with Primula denticulate Smith, are obtained by wet granulation method and to substantiate the choosing of the best excipients by the method of mathematical planning of the experiment.

Materials and Methods. It was used a self-prepared dense extract of Primula denticulate Smith. and excipients, which are complied with the requirements of State Pharmacopoeia of Ukraine in terms of pharmaco-technological quality parameters, for developing tablets. The hyper Greek-Latin square 4x4 was used to study the four qualitative factors.

Results and Discussion. In the course of the experiment, it was determined the dependence of pharmaco­technological parameters (friability, resistance to crushing and disintegration of tablets) on type of excipients. It was selected excipients with the optimal pharmaco-technological parameters for further research the tablets quality.

Conclusions.

According to the method of mathematical planning of the experiment, it’s chosen the optimal excipients for obtaining tablets based on dense extract of Primula denticulate Smith. Considering the investigated pharmaco-technological properties (friability, resistance to crushing and disintegration of tablets) the qualitative composition of excipients for obtaining tablets by the method of wet granulation was determined: Avicel PH - 105 and MCC 101, croscarmellose sodium, colloidal anhydrous silicon dioxide, magnesium stearate and Prosolv 90.
The study of the antidepressant and actoprotective activity of a synthetic analog of the terminal region of neuropeptide Y
Authors: Havrylov I. O. , Shtrygol’ S. Yu.
Published: April 2021

Topicality. Neuropeptide Y (NPY), which is significantly widespread in the human body, is responsible for various physiological processes, in particular it is involved in the regulation of the emotional behavior, memory and metabolism. The modified short fragment of NPY proposed – NP9 nonapeptide for intranasal administration – shows certain biological properties of the native peptide, in particular the anxiolytic and antiamnesic action. The effect of NP9 on affective disorders of depressive nature and physical endurance remains unknown.
Aim. To study the antidepressant and actoprotective activity of NP9 in models of tail suspension, reserpine-induced depression, and forced weighted swimming.
Materials and methods. The antidepressant properties of NP9 were studied in the immobilization tail suspension test in mice and on a model of reserpine-induced depression with registration of the body temperature, ptosis, and behavior in the Porsolt forced swimming tests and the open field test. The actoprotective properties of NP9 were studied in the swimming test with a load (10 % of the weight of the animal).
Results and discussion. In the tail suspension test, NP9 significantly increased the latent time of the first immobilization compared to the indicators of intact animals (3.2 times) and the imipramine group (2.7 times). NP9 did not significantly affect the manifestations of reserpine-induced depression. These results indicate the weak antidepressant properties of NP9. Nonapeptide significantly increased the swimming time to exhaustion by 2.5 times, indicating actoprotective properties, according to which NP9 exceeded the reference drug Semax.
Conclusions. In the tail suspension test, nonapeptide NP9 exhibits dose-dependent antidepressant properties after the first administration, but this effect is practically not manifested in the rigid reserpine-induced model of depression. NP9 increases the physical endurance of animals in the forced weighted swimming test and is superior to the reference drug Semax by its effectiveness.
The study on the development of the technology of the Sedum maximum juice as a biogenic stimulator for obtaining medicines
Authors: Burban O. I. , Vyshnevska L. I. , Zubchenko T. M.
Published: April 2021

Due to the complex of biologically active substances (BAS) in the native state, juices are becoming increasingly popular in pharmacy and medicine. We were interested in the Sedum maximum plant as a powerful biogenic stimulant. Despite its wide distribution in the world and in Ukraine, plants of the Sedum L. genus are rarely used.
The aim of the study is to determine the technological parameters of the process of obtaining juice from Sedum maximum for the development of technology for its production in pharmacy and industrial conditions and further use in pharmacy and medicine.
Results. The optimal method of obtaining fresh juice from Sedum maximum grass using a number of technological techniques in the following sequence was substantiated: fermentation of Sedum maximum grass (keeping in a dark cool place (5 ± 3 ºC) for 5 days; pre-treatment of Sedum maximum grass raw material with boiling water; keeping the crushed raw material at a temperature of 5 ± 3 ºC during the day, purification of unclarified juice with rapid heating to 75-78 °C for 30 min followed by rapid cooling and treatment with 95 % ethanol, sedimentation of Sedum maximum grass juice at a temperature of 5 ± 3 ºC followed by stabilization of clarified juice of Sedum maximum grass with ethanol 15% and chloroethane in the amount of 0.5 %.
Conclusions. The quality criteria of the obtained Sedum maximum juice were determined: appearance, pH, dry residue, identification by color reactions and quantitative determination by spectrophotometry (sum of tannins, in terms of pyrogalol).
Key words: juice; Sedum maximum; technology; biogenic stimulant
Methodological aspects of creating a soft dosage form with the antiviral effect
Authors: Hrytsenko V. I. , Kienko L. S. , Bobrytska L. O. , Zlagoda V. S.
Published: April 2021

Aim. Substantiate the methodology of creating the soft dosage form for the treatment of herpes viral diseases, taking into account the existing requirements for pharmaceutical drug development.

Materials and methods. Drug creating is possible only with a theoretically and experimentally justified process of planning experimental research. To ensure the effectiveness and minimize side effects of the drug under development, it is necessary to take into account all pharmaceutical factors that have affect on the quality of the drug. These are the nature and quantity of the base, physical and chemical properties of active and auxiliary substances, structural and mechanical characteristics and equipment.

The methodological concept of antiviral drug development is based on the implementation of complexes of marketing, pharmaco-technological, physico-chemical and biopharmaceutical research, which ensures compliance of the drug with medical and biological requirements.

Results. It was found that the general algorithm of the methodological approach consists of 3 consecutive stages: information retrieval, research and standardization-pharmacological. Based on the analysis of literature sources and own research, a plan for creating of the soft dosage form with the antiviral effect based on acyclovir and miramistin was developed.

Conclusions. The main methodological aspects of creating the soft dosage form with antiherpetic action, taking into account the requirements for the quality of the drug are shown.

Key words: methodology; drug; research algorithm; soft dosage form
Differences between Israeli Jewish and Arabs mothers in parental self-efficacy: A cultural perspective
Authors:   School of Social Work, Zefat Academic College, Israel, David Vered Ben , Khatib Anwar ,   School of Social Work, Zefat Academic College, Israel
Published: April 2021

Parental self-efficacy (PSE) is a key to the child-parent relationship. It reflects parents’ self-perception of their ability to perform parenting tasks successfully and a high level of parental self-efficacy is associated with positive child outcomes. The literature on cultural differences regarding PSE is scant. This study applied a cultural perspective and examined differences between Arab and Jewish mothers with regard to PSE and associated factors such as marital satisfaction, social support, wellbeing and stress. Based on a sample of 170 married mothers in Israel, it revealed that Arab mothers experienced a higher degree of PSE, marital satisfaction and wellbeing, as well as lower stress, than Jewish mothers. PSE among Arab mothers was predicted by marital satisfaction and stress. Among Jewish mothers, PSE was predicted by stress and wellbeing as well as financial indicators. The paper discusses the findings from a cultural perspective, focusing on the experience of parenting in an Arab, collective, traditional and patriarchic society compared to parenting in a Jewish, individualistic, liberal society. The study concludes that it is important to consider the cultural context of parenting to the sense of parental efficacy and to understand the cultural norms and values of individuals whose parenting capacity comes under assessment. Based on the findings it was suggested that family therapy or spousal therapy may provide benefit to Arab mothers who report a low level of PSE. For Jewish mothers, alleviating financial hardship and providing material help could provide similar benefits, in addition to lowering the mother’s level of stress. Limitations of the study as well as future studies directions were also discussed.
THE GENERAL PRINCIPLES OF GOOD GOVERNANCE IN THE MIND OF RAJA ALI HAJI
Authors: Sucipta Pery Rehendra , S Rilo Pambudi
Published: April 2021

This brief writing tried to challenge the old thinking that led everyone to the Raja Ali Haji figure as a literary and cultured man in the 19th century of the Malay Kingdom of Riau-Lingga. Whereas he was a multidisciplinary of science, who also included the politics, government, and constitutional law. His expertise on that subject was inseparably based on his experience as a kingdom adviser. As well as two books that specifically containing a law thought that are Muqaddimah fi Intizam and Tsamarat Al-Muhimmah. This study uses a normative juridical approach with the quality of research is analytic descriptive. The studies explain that: First, the legitimacy of Raja Ali Haji as a jurist, among other things: Gurindam Dua Belas is not a mere literacy work, it also includes the idea of contitutional law; the kingdom adviser; and review of his books. Second¸the general principles that are included in Muqaddima fi-Intizam and Tsamarat al-Muhimmah include the principle of consensus, the principle of prudence, the principle of juctice, the principle of unfairness, the principle of professionality, the principle of accountability, the principle of legality, the principle of public interest, and the principle of not mixing authority.
Acidente vascular cerebral isquêmico em paciente portador de forame oval pérvio: estudo de caso
Authors: Lemos Bárbara Alvim Raposo , Ochsendorf Fauzer Cury , Resende Maria Eduarda Calazans
Published: April 2021

Objetivo: Relatar o caso de paciente portador de Forame Oval Pérvio (FOP), que evoluiu com Acidente Vascular Cerebral (AVC) criptogênico, correlacionando com os dados disponíveis na literatura acerca da fisiopatologia, quadro clínico, diagnóstico e tratamento. Detalhamento de caso: Paciente F.C.L., sexo masculino, 48 anos, sem comorbidades, apresentou episódio de visão turva associado com desvio de rima à esquerda e perda de força em membro superior esquerdo, com retorno em menos de 24 horas. Realizou ressonância magnética de crânio que comprovou AVC isquêmico. A ecocardiografia transesofágica confirmou o diagnóstico de FOP. Vários exames complementares foram realizados, mas não houve associação com outra etiologia. A conduta estabelecida foi a oclusão percutânea transcateter do forame, juntamente com tratamento medicamentoso. Considerações finais: É de suma importância o avanço nos estudos que englobam o AVC criptogênico e seu manejo, assim como sua associação com forame oval pérvio, já que o diagnóstico e tratamento interferem diretamente na sobrevida e na qualidade de vida do paciente.
As faces da violência obstétrica no âmbito hospitalar
Authors: Júnior Adilson Mendes de Figueiredo , Moraes Alda do Socorro Cardoso , Silva Clebson Luis Trindade da , Cobel Juliana de Souza , Pinho Kamyla Pinto , Pimentel Maria de Jesus Evangelista , Silva Carlos Kayque Araújo da , Costa João Victor Tavares da , Melo Paula Amanajás de , Rocha Sabrina Macambira Guerra da
Published: April 2021

Objetivo: Realizar um levantamento sobre os tipos de violência obstétrica que ocorrem em mulheres durante a assistência ao parto no âmbito hospitalar. Métodos: O estudo foi do tipo qualitativo descritivo com o intuito de realizar um levantamento dos principais tipos de violência obstétrica que ocorrem durante a assistência ao parto em âmbito hospitalar através de uma Revisão Integrativa da Literatura. Resultados: Verificaram-se as condutas adotadas após a ocorrência da violência obstétrica durante a assistência ao parto e quais as intervenções que podem ou são realizadas pelo enfermeiro de acordo com a literatura. Considerações finais: É necessário o treinamento de profissionais da saúde para promover um atendimento humanizado e adequado para cuidados de saúde da mulher. Portanto, há necessidade de estudos que destacar a questão entre os profissionais de saúde, com ênfase nas boas práticas incluídas nele e conformidade e conformidade com leis, punições e formas de denúncia, para promover a reflexão sobre eles e adoção de comportamentos mais profissionais e aceitáveis.
Aspectos sociais e biológicos da autoestima na gravidez e a assistência de enfermagem: revisão narrativa
Authors: Dias Geovanna Lopes , Da Silva Camille Borges , Araújo Erlisson de Sousa , Lima Bárbara Batista , Saraiva Adriana Paiva Camargo , Silva Jerônimo Cavalcante Dantas , Gentil Raphael do Nascimento , De Oliveira Thamyris Andrade , Carneiro Priscilla Rodrigues Caminha
Published: April 2021

Objetivo: Compreender os fatores que influenciam negativamente a autoestima de gestantes e como a assistência de Enfermagem pode atuar durante o pré-natal, sob aspectos sociais e biológicos. Revisão bibliográfica: Os artigos utilizados foram consultados nas bases de dados Scientific Eletronic Library Online (Scielo), Google acadêmico e Biblioteca Virtual em Saúde (BVS) por meio de palavras-chave combinadas entre si com o operador booleano AND, na busca por estudos científicos que abordassem problemas e soluções relacionados a baixa autoestima durante a gravidez. A revisão foi dividida em mudanças anatômicas e fisiológicas, alterações dermatológicas, fatores socioeconômicos e outros. De acordo com a literatura analisada, a baixa autoestima entre gestantes pode estar associada a estrias, celulite, modificações hormonais e físicas, bem como planejamento da gravidez, apoio familiar e do parceiro. Os meios relativos de solução como: o uso de hidratantes, protetor solar, o pré-natal de qualidade e o apoio familiar contribuem para melhorar a autoestima da gestante. Considerações finais: Pode-se dizer que a assistência de enfermagem durante o pré-natal é fundamental para fornecer informações de qualidade quanto às mudanças anatômicas e fisiológicas, e incentivar o parceiro e familiares ao apoio da gestante.
Efeitos de extrato em gel de chenopodium ambrosioides l. (mastruz) no tratamento de lesões ósseas de ratas osteoporóticas
Authors: Trindade Gustavo Diniz , Filho Antônio Luiz Martins Maia , Rodrigues Jairelda Sousa , Ferreira Daniel Cabral Leão , De Araújo Karinne Sousa
Published: April 2021

O objetivo foi produzir extrato em gel de Chenopodium ambrosioides e analisar os efeitos do uso tópico no reparo ósseo de ratas osteoporóticas, realizando triagem fitoquímica para identificação de taninos e saponinas, verificando microscopicamente o processo inflamatório durante a reparação e neoformação óssea pós-lesão. Para produzir o extrato de mastruz utilizou-se folhas frescas. Após trituração o líquido foi incorporado ao carbopol para obter consistência gelatiniforme. Para analisar os efeitos do extrato em gel foram utilizadas 12 ratas Wistar com osteoporose induzida, divididas em dois grupos. No grupo 1, o defeito ósseo foi preenchido por coágulo sanguíneo; e no grupo 2, com gel do extrato de mastruz. Por triagem fitoquímica identificou-se taninos e saponinas no extrato em gel de mastruz. Aos 30 dias, no grupo 1, observou-se leve infiltrado inflamatório preenchido por espículas ósseas delgadas e intercomunicantes formadas por tecido ósseo primário. No grupo 2, identificou-se formação de trabeculado ósseo espesso constituído por tecido ósseo primário e secundário, com defeito ósseo recoberto por periósteo e ausência de sinais inflamatórios. Foi produzido extrato em gel de mastruz gelatinoso com presença de taninos e saponinas, identificados por triagem fitoquímica, mostrando-se favorável na reparação óssea em defeitos cirúrgicos realizados nas tíbias das ratas osteoporóticas.
3D printing of PLA and PMMA multilayered model polymers: an innovative approach for a better-controlled pellet multi-extrusion process
Authors: Yousfi Mohamed , Belhadj Ahmed , Lamnawar Khalid , Maazouz Abderrahim
Published: April 2021

The present work deals with the 3D printing of multimaterials based on PLA/PMMA multilayers directly obtained from pellets. This polymer pair was chosen for their miscibility at the melt state and synergistic properties (i.e., to improve and weather tune the temperature resistance, transparency and thermomechanical properties of their PLA-based materials). Thus, 3D-printed parts with repeating PMMA/PLA/PMMA layers in the Z building direction were successfully prepared in different numbers but maintaining the same composition. The main objective was to better understand the interface/interphase properties developed during this innovative processing. First, further physicochemical and dynamic thermomechanical characterizations were performed. Second, the effects of multi-extrusion 3D printing processing parameters on the thermal stability of PLA, PMMA and their printed specimens were analyzed by GPC. Then, the structuralrheological and mechanical properties of the multilayered systems were investigated in comparison to their equivalent blend. The effects of flow kinematics during extrusion as well as printing chamber temperature (PCT) and infill density (ID) were specifically studied and rationalized. The triggered interfaces were characterized by SEM and subjected to flexural and short-beam three-point bending experiments that proved their dramatic influence on the final mechanical properties. The ultimate aim of this study is to enable successful control of the interfaces/interphases obtained in these 3D-printed PLA/PMMA systems in comparison to other forming processes.
Forming Using Polyurethane Plate for stamping Various Materials type Austenitic Steel, Aluminium Alloys, Copper Alloys
Authors: Bałon Paweł , Kiełbasa Bartłomiej , Kowalski Łukasz , Szostak Janusz
Published: April 2021

The rubber and elastomer molding process has been used for many years in the aviation industry for piece production, small series. Due to the current development of plastics in the field of polyurethane, it is possible to obtain a plate hardness of 40-95 SHA, which allows for deep drawing of containers of various purposes. An additional argument is the price of the material, which is several times lower in relation to rubber or fibroflex products. This allows the flexible punch forming method to be used for special or prototype applications, where the costs and time of tool production are the main argument. The paper presents one geometric model of a container, but formed from different materials, i.e. steel with a high content of chromium, aluminum alloy, copper, in order to compare the differences in their intended use, as well as the production method.
Modeling of failure at the interface of ductile materials by applying the cohesive discontinuous Galerkin method
Authors: Bayat Hamid Reza , Harandi Ali Rajaei , Rezaei Shahed , Brepols Tim , Reese Stefanie
Published: April 2021

In this study, the failure behavior at the interface of ductile materials is investigated. In order to capture the degradation of the tractions at the interface, a cohesive zone (CZ) model is applied. The choice of the type of the CZ approach, i.e. either intrinsic or extrinsic, brings about different drawbacks. The former includes an elastic regime at the interface prior to the failure, which can result in numerical difficulties whereas the latter necessitates the re-meshing of the structure during crack propagation. In order to overcome these problems, the incomplete interior penalty Galerkin variant of the discontinuous Galerkin (DG) method is applied both at the interface and in the bulk instead of the standard conforming finite element method. In addition, the application of the DG method enables to use nonmatching meshes in the discretized model. To treat the bulk, an elastoplastic material model with isotropic hardening as well as different hardening rules for small strains is incorporated into the DG framework. Two numerical examples are computed to study the convergence behavior of the new cohesive discontinuous Galerkin (CDG) method in comparison to that of the conventional models. The new CDG method outperforms the conventional CZ continuous Galerkin elements in the presence of locking effects as well as hanging nodes.
Motion profile calculation for freeform bending with moveable die based on tool parameters
Authors: Werner Matthias Konrad , Maier Daniel , Scandola Lorenzo , Volk Wolfram
Published: April 2021

In freeform bending the desired geometry is created by defined movements of the die while a continuous feed takes place. To compensate the differences and variations in properties of the semi-finished product, the motion profile has to be adjusted. Currently, this calibration is done once before the manufacturing process of a certain profile. Therefore, numerous iterations consisting of bending and measuring certain radii based on a default motion profile are performed. The measured data is subjected to a curve fit, which is not sufficiently suitable for all profiles and materials setups due to the fixed predefined function that is used. Furthermore, the tool setup is not taken in account. This results in wrong kinematics and production rejects. In this work, an enhanced geometrical model is introduced which incorporates tool parameters - such as distances, clearances and positioning aspects - as a starting point for further calculations. Furthermore, different calibration methods are tested and compared to each other using FEM simulations to fit the calculated curve to the actually used specimen. This work establishes the basis for further compensation and calibration strategies in order to improve the handling of varying properties of semi-finished products within the freeform bending process.
Roughness development of polymer coated steel during the production process of a can
Authors: Venema Jenny , Jonker Fred , Stegeman Richard
Published: April 2021

Polymer coated steels are used in the packaging industry to produce a variety of products, for example cans. During the production of the cans, the steel substrate and the polymer undergo a roughness development. The roughness development is important regarding the product performance and depends (among others) on the original grain size of the steel substrate. The goal of this paper is to investigate the influence of the grain size of the steel substrate on the surface roughness during the production process of the can. For this purpose, 3D topography measurements were performed after several process steps (drawing, redrawing and ironing) of can making. A larger grain size results in a higher roughness increase and a lower minimum coating thickness of the inside of the can.
On the Effects of Burnishing Process on Tribological Surface Resistance of Additively Manufactured Steel
Authors: Saffioti Maria Rosaria , Sanguedolce Michela , Rotella Giovanna , Filice Luigino
Published: April 2021

Burnishing is a Severe Plastic Deformation process having the potential to replace expensive finishing post processes. It is considered a super finishing process due to its results in terms of drastic roughness reduction. Also, additional advantages include the surface integrity improvement functionalized to the specific application. Even though burnishing is widely applied for surface improvement of conventional materials, knowledge about its effect on additively manufactured metals is still limited. This paper aims to fill this gap presenting experiments on roller burnishing on additively manufactured stainless steel in order to improve its tribological performance. The experimental campaign was carried out to find suitable process parameters able to drastically improve the tribological behavior of the final product. In particular, the influence of the burnishing forces on the whole surface quality has been addressed. The overall results demonstrate that the selected burnishing configuration is able to successfully modify the surface characteristics of the steel, making it appropriate for critical applications. Furthermore, the experimental findings allow to conclude that burnishing process can replace a series of post processes needed after additive manufacturing, drastically reducing the time and costs associated to the manufacturing process and meeting Industry 4.0 requirements.
Effect of PEEK degradation on commingled fabrics consolidation
Authors: Feuillerat Lisa , De Almeida Olivier , Fontanier Jean-Charles , Schmidt Fabrice
Published: April 2021

The effects of PEEK degradation on consolidation of commingled semi-finished products have been investigated. Two commingled semi-finished products provided by two different suppliers have been studied and compared to a powdered fabric based on the same PEEK grade. Both were manufactured from aligned AS4 carbon and PEEK yarns but the first product referred as the NCF1 has a lower commingling level than the second one identified as the NCF2. Contrary to what could be expected, under the same processing conditions, consolidation of the NCF1 and the NCF2 systematically results in a high porosity content, above 10%. Fourier Transform Infrared spectrophotometry (FTIR) in ATR mode and Gel Permeation Chromatography (GPC) have shown small molecular structure modifications of PEEK yarns compared to the raw material, such as a shift of molar mass distributions towards lower molar mass and the appearance of C-H absorption bands attributed to non-aromatic alkanes. These modifications have been attributed to sizing of PEEK filament. Calorimetric (DSC) and rheological analyses have demonstrated that the presence of sizing in the semi-finished products have huge consequences on the degradation kinetics. The crystallization temperature decreases and the viscosity increases significantly. This acceleration of the degradation kinetics is the reason of the poor consolidation behavior during composite manufacturing. The conditions of melt spinning extrusion under which the neat PEEK is transformed into filament are therefore a key factor of PEEK degradation.
Finite element modelling of the Taylor impact test in 3D with the Coupled Eulerian-Lagrangian method
Authors: Ducobu François , Demarbaix Anthonin , Pantalé Olivier
Published: April 2021

When modelling a cutting operation, the constitutive model of the machined material is one of the key parameters to obtain accurate and realistic results. Up to now, the Johnson-Cook model is still the most used, even if an increasing number of models, such as the Hyperbolic TANgent (TANH) model, were introduced last years to overcome its limitations and come closer to the actual material behaviour. Experimental tests on dedicated equipment are usually required to identify the parameters of the constitutive models. This paper introduces the Coupled Eulerian-Lagrangian (CEL) formalism to model in 3D the Taylor impact test, one of the common tests to perform that parameters identification. Indeed, one identification way involves modelling the test to determine the constitutive model parameters by comparing the experimental and the numerical samples geometries. The developed CEL model is validated against a Lagrangian reference model for a steel alloy and the Johnson-Cook constitutive model. The main goal of using the CEL method is to get rid of the elements distortion due to the high strains and strain rates during the test. Mesh dependence of the results is highlighted and a recommendation is provided on the mesh to adopt for future work. The CEL model of the 3D Taylor impact test is then extended to the use of the TANH model. The results are finally compared with that of the Johnson-Cook constitutive model.
Sequential dual sided SPIF using low order geometry reconstruction
Authors: Carette Yannick , Duflou Joost R.
Published: April 2021

Harmonic decomposition is an analytical technique that is able to express a manifold surface as the sum of a number of simple surface harmonic components. By reconstructing the initial geometry using a reduced number of components, a similar surface is obtained with a lower level of geometric detail. Because small features are filtered out and the resulting surface lies equal parts above and below the original surface, a tailored multi-step SPIF (Single Point Incremental Forming) processing strategy can be devised. This sequential SPIF strategy uses three processing passes to form a workpiece. The first step is a regular SPIF operation using a conventional toolpath strategy to form the reduced geometry. Two finishing steps are then needed, one from the same side to form the smaller features that lies deeper than the reduced geometry and one backwards pass from the other side of the sheet. To add features that need to be shallower than the reduced geometry, the part is flipped around. The used sequence of these finishing steps and the toolpath strategy used significantly influence the final part accuracy and surface quality. The advantages and disadvantages of four of these combined strategies are examined and compared to regular SPIF.
Material characterisation methods for a tumbling self-piercing riveting process
Authors: Wituschek Simon , Lechner Michael
Published: April 2021

The growing demands of resource-saving processes and products are leading to increasing importance of lightweight construction for the automotive industry. One approach is multi-material design, which uses high-strength steels and aluminium alloys in the production of vehicle bodies. Therefore, reliable processes for joining components with different mechanical properties and geometries are necessary. As conventional joining processes reach their limits, new versatile processes and methods are required which can adapt to different process conditions and disturbance variables. A widely used joining process to join different materials is self-piercing riveting as a joining by forming method, however it is characterised as inflexible to changing process conditions due to a linear process kinematic and rigid dies. An approach to extend the process limits is the application of a tumbling kinematic for the punch. Thus, an adapted tumbling strategy can be used to influence the joining process and to achieve a controlled material flow in order to manufacture tailored joints. For the fundamental investigation of the process, numerical investigations are necessary. In order to achieve high model quality a precise material modelling is crucial. Therefore, a characterisation of the materials HCT590X+Z and EN AW-6014 as typical materials of multi-material mixes and the rivet material 38B2 is performed. Due to the different stress conditions during tumbling self-piercing riveting suitable characterisation methods are selected and carried out.
XPS and SEM characterization for powder recycling within 3d printing process
Authors: Gorji Nima E. , O'Connor Robert , Brabazon Dermot
Published: April 2021

In recent years, recycling the powder leftover within the additive manufacturing process has been attractive for both research, development and industry production. Powder recycling can significantly enhance the sustainability of the manufacturing process, reduce the cost and avoid producing metallic waste as a potential environmental hazard. The first step in reusing the recycled powders in the 3D printing process is to characterize the microstructure and surface quality of the powder for oxidation and impurity analysis. Here, scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) have been used for the morphology and surface composition analysis of the 316L powders within the Aconity 3D printer. A new powder collection strategy has been introduced to collect powders from different locations in the powder bed: from the top most and surface of the parts and powder bed after the print terminated, from between the printed parts at different heights. The XPS measurements revealed that oxidation is a common in all the powders compared to virgin powder and more oxidation was detected from the powders collected on the very top of the leftover powder and from surface of the bed. The size of the particles does not change much but larger particles remained at the topmost surface. This finding would help in designing a protocol for collecting the recycled powder from the powder bed and it is suggested to follow a a procedure of collecting powders from the different sections of the powder bed in order to avoid mixing the most and least affected particles.
On the Elastoplastic Behavior of Friction Stir Welded Tailored Blanks for Single Point Incremental Forming
Authors: Tucci Fausto , Andrade-Campos António , Thuillier Sandrine , Carlone Pierpaolo
Published: April 2021

The current market requirements are increasingly pushing the industry towards the manufacturing of highly customized products. Tailored blanks are a class of sheet metals characterized by the local variation of properties, attributable to the presence of different materials, different thickness distribution, and thermal treatments. In the manufacturing of tailored welded blanks, welding and forming processes cover a central role. In this framework, friction stir welding demonstrated to be a suitable candidate technology for the production by joining of tailored blanks. Indeed, sheet metals welded by this solid-state welding process typically exhibit high formability when compared to the conventional welding methods. Due to the improved formability, a good deal of attention has been recently given toward the single point incremental forming (SPIF) process and its integration with FSW. Remarkable efforts have been dedicated to the numerical modeling of the SPIF of metallic alloy sheets jointed by FSW. The main criticisms in these models are related to the definition of the mechanical properties of the materials, which are affected by the structural alteration induced by the FSW. The present work aims to model the local alterations in the mechanical properties and to analyze how these local characteristics affect the formability of the blanks. With this purpose, a 20 mm wide sample collected from a FS welded blank of aluminum alloy AA6082 has been modeled using the mechanical properties variation achieved in a previous work. The influence of this local variation in properties has been assessed using a Finite Element Model Updating strategy.
Integrating layer by layer manufacturing for the realization of polymer complex geometries with scanning devices: re-building by digital data
Authors: Bruni Carlo , Greco Luciano , Mancia Tommaso , Pieralisi Massimiliano
Published: April 2021

The additive manufacturing technique represents a way to realize components or prototypes without the use of conventional tools.The research presented aims at proposing a methodology based on the use of three different techniques that are the poly-jet 3D using UV photo-polymerization, the FDM of polyamide materials and the FDM of PLA materials. The original data were used at the beginning with the first technique in order to detect the shape and the geometry by a 3D SCANNER. The objective was the re-building of a model shape made using a procedure in which the input file characteristics were updated starting from those got by the scanning device in order to respect the original requirements defined in the computer aided environment. It was found that the physical re-building of an object is depending the characteristics of the input file that needs to be digitally processed in order to get the desired shape and geometry. In that way also FDM using PLA and polyamide materials can be utilized to get components or prototypes from scanned digital data. The results are reported in details.
Joining of Sheets with Tubes by Electrohydraulic Forming
Authors: Langstädtler Lasse , Herrmann Marius , Schenck Christian , Kuhfuss Bernd
Published: April 2021

Electrohydraulic forming is a high-speed process, which is based on a force transmission by a working media. In this process, shock waves transmit the punching force in a very short period of time. These shock waves are applied to accelerate the workpiece towards a passive die. Besides forming and embossing of sheets and tubes, joining of sheets with tubes is enabled as a novel application presented in this contribution. Thereby, the tube is embedded temporarily in the die as a functional part. By accelerating the sheet towards the tube end, the joint is formed. This study deals with the question of how this joint is formed in sense of process kinematics and material flow. Therefore, the loading energy, the distance of sheet and tube as well as the sheet thickness was varied and the influence of these parameters and geometric conditions of the tube on the process and resulting joints was observed. Joining of EN AW-1050 aluminum alloy sheets to EN AW-6060 aluminum alloy tubes was performed. These joints were analyzed by microsections and head tension tests. The investigations introduce the new joining process regarding its process behavior and show first joining results.