bluuebunny/crossref_metadata_2025 huggingface dataset:
Violence and “Hyperbologic”: Lawlor on Time’s Relation to Metaphysics
Authors: Angelova Emilia
Published: September 2018

In his recent work, Leonard Lawlor draws attention to the problem of “violence,” which is the “problem that provides the most food for thought.” This emphasis on the problem of violence and its connections to metaphysics understood as philosophy has been remarkably consistent over his career, and thinking through responses to “violence” has sustained Lawlor’s continued effort to think about what he calls “violent” relations between event and repeatability and ground these upon a critical phenomenology. This contribution to the discussion of Lawlor’s work focuses on his most recent book, From Violence to Speaking Out (2016), so as to suggest three important directions for this project and for philosophy’s response to violence. I first briefly trace the theme of violence in From Violence to Speaking Out, contextualizing it against the rest of his work, so as to draw out what he means by violence and its provocation to philosophy, with special attention to the way that the violence in question is figured as disrupting the transcendental and confronting philosophy with what Lawlor calls the “ultratranscendental.” Second, I link it to the theme of time by tracing Lawlor’s point about violence in relation to the breaking up of the transcendental subject from Kant into Heidegger. Third, I link these points to the negative movement of the dissolution of modes of repeatability. This dissolution is captured in a kind of “speaking‐out” that Lawlor detects in Foucault, Derrida, and Deleuze and Guattari, involving an excess over and above expression, which Deleuze calls “hyperbologic.”
Prospective mathematics teachers’ expectations for middle grades students’ arguments
Authors: Suominen Ashley L. , Conner AnneMarie , Park Hyejin
Published: September 2018

In this study, 15 prospective secondary (grades 6–12) mathematics teachers were asked to situate themselves as middle school (grades 6–8) mathematics teachers and validate arguments purported to prove that the sum of the first n odd natural numbers is. We examined their stated expectations for middle school students’ mathematical arguments and the rationales given for these expectations. Even though the participants were situated as middle grades teachers when evaluating hypothetical student arguments, not all of the participants embraced this perspective when discussing their expectations for middle school students’ arguments. In fact, only six participants embraced the teacher perspective, whereas nine participants relied, at least in some part, on their own experiences as students to determine their expectations for student work. In this article, we report five representative participants’ expectations and rationales to illustrate three emerging perspectives on prospective teachers’ expectations for middle school students’ arguments.
Introduction
Authors: Schreier Joshua
Published: September 2018

Jacob Lasry (1793-1869), a North African Jewish merchant, offers a useful optic for reevaluating Jews’ role and influence in pre- and early-colonial North Africa, as well as the early effects of colonialism on the society and economy of the small Mediterranean port of Oran. Against traditional accounts that emphasize the pre-colonial desolation of Oran and the precarious status of most Algerian Jews, this study underlines Oran’s nascent revival, as well as the influence, dynamism, and worldliness of Jews such as Lasry in late Ottoman/early colonial Oran. French forces actually relied on local North African talent (such as Lasry) not only to help finance and coordinate the conquest, but even to direct some of colonialism’s “ideological” work, such as bringing local Jews into the French orbit. By following these threads, this study offers an unprecedented “personal” account of French colonialism in Algeria.
From Juifs de Gibraltar and “Algerine Jews” to Israélites Indigènes
Authors: Schreier Joshua
Published: September 2018

This chapter explores a series of interactions and struggles involving synagogues, religious rituals, and the meaning of “indigenous,” to demonstrate how French colonial policies fashioned new lines of identification. The French casting of a diverse, feuding, and recently established array of Oran’s inhabitants as a single community of “indigenous Jews” changed Oran’s social landscape. Notably, it helped create what was later understood to be a religious “minority.” Institutions such as the consistory (and later, Jewish naturalization), seeking to remedy newly conceived pathologies such as “jealousies” or “problems of civilization,” formed a new Jewish subjectivity. French policies did not reflect existing racial or religious topographies in Algeria so much as reify or even create them. In the place of the collection of diverse, dynamic, and often powerful individuals explored in previous chapters, French imperialism posited an identifiable community of israélites indigènes.
North Central, South Side
Authors: Ronda Margaret
Published: September 2018

The opening chapter reads two mid-century poets, Lorine Niedecker and Gwendolyn Brooks, as chroniclers of socioecological transition in the immediate postwar period. While environmental historians have recently turned attention to the suburbs as the key site of inquiry into changing postwar conditions, the chapter emphasizes the rural and urban peripheries as locales that reveal many of the emerging characteristics of the Great Acceleration. Turning first to Lorine Niedecker, the chapter describes her development of a poetics attentive to uneven development, residual forms of life, and ecosystemic degradation in the mixed economy of rural Wisconsin. The second half of the chapter moves from Niedecker’s rural Wisconsin to Brooks’s urban Chicago. Brooks explores the production of space in relation to the forms of environmental racism emerging in South Side housing and neighborhood conditions after 1945.
Mourning and Melancholia at the End of Nature
Authors: Ronda Margaret
Published: September 2018

This chapter begins with a consideration of the development of the discourse of the “end of nature” and its implications for understanding ecological relations. Pointing to the elegiac dimensions of this discourse, the chapter turns to Juliana Spahr’s long poem “Gentle Now, Don’t Add to Heartache” as an example of a literary exploration of the consequences of this conceptual absence. The chapter draws on the Romantic philosophy of Schiller as well as more recent psychoanalytic accounts of elegy and mourning to argue that the operations of elegy become the subject of investigation in Spahr’s work. “Gentle Now” serves as a representative eco-elegy that dwells in melancholia rather than moving toward the completion of the mourning process. The chapter closes with a consideration of a more recent poem by Spahr, co-written with Joshua Clover, that investigates the affective and political limits of melancholy as a response to present conditions.
Stalinallee
Authors: Stangl Paul
Published: September 2018

For more than a century before the war, debate over the “housing issue” engaged politicians and reformers in Berlin, although Communists refused to participate, seeking revolution rather than reform. After World War II, newly empowered Communists had no choice but to address the housing crisis. Initially they joined others in supporting modernist planning efforts, with a first “residential cell” that would be constructed along Frankfurter Allee in Friedrichshain. The introduction of socialist realism necessitated a halt in construction as new plans for a monumental Stalinallee were developed. This formed the centerpiece of the state building program until the 1953 Uprising, which along with a shift to industrialized construction in the Soviet Union would result in a search for a new “socialist architecture.” As a result, the section of the street between Straussbergerplatz and Alexanderplatz would be built combining some socialist-realist tenets with modernism, while highlighting technological power.
Conclusion
Authors: Stangl Paul
Published: September 2018

Key cultural and political groups displayed a great deal of internal unity in their approach to the urban landscape due to their adherence to the same frameworks of interpretation and political interests. This is not to imply that humans agency was irrelevant. Individuals and groups created and altered these frameworks, and made decisions about how to apply them to the city. The triad of place-based meaning, spatial/formal relations and representation was consistently significant, albeit with vastly different levels of importance attached to each on a case-by-case basis. The differential treatment of memorials, monumental architecture, vernacular buildings, public spaces, and city plans suggests that they differed in how they conveyed cultural meaning. The construction of the Berlin Wall in 1961 made an emphatic statement about the GDR that would always stand as a counterpoint to its other building projects.
To Sin No More
Authors: Rex Galindo David
Published: September 2018

For 300 years, Franciscans were at the forefront of the spread of Catholicism in the New World. In the late seventeenth century, Franciscans developed a far-reaching, systematic missionary program in Spain and the Americas. After founding the first college of propaganda fide in the Mexican city of Querétaro, the Franciscan Order established six additional colleges in New Spain, ten in South America, and twelve in Spain. From these colleges Franciscans proselytized Native Americans in frontier territories as well as Catholics in rural and urban areas in eighteenth-century Spain and Spanish America. This is the first book to study these colleges, their missionaries, and their multifaceted, sweeping missionary programs. By focusing on the recruitment of non-Catholics to Catholicism as well as the deepening of religious fervor among Catholics, the book shows how the Franciscan colleges expanded and shaped popular Catholicism in the eighteenth-century Spanish Atlantic world. This book explores the motivations driving Franciscan friars, their lives inside the colleges, their training, and their ministry among Catholics, an often-overlooked duty that paralleled missionary deployments. It argues that Franciscan missionaries aimed to reform or “reawaken” Catholic parishioners just as much as they sought to convert non-Christian Native Americans.
Recruiting Missionaries
Authors: Rex Galindo David
Published: September 2018

This chapter focuses on the recruitment of novices and friars to become Franciscan missionaries. To convert the Hispanic world, Franciscan colleges for the propagation of Catholicism had to recruit friars. In this regard, they were highly effective. Throughout the eighteenth century, the colleges became the most successful recruiting force of Peninsular personnel for the Americas in a trans-Atlantic flux that underscores the Spanishness of the propaganda fide institution. The chapter examines how a Franciscan college went about its business of enlisting missionaries by describing the selection process as well as the level of education of novices and friars before admission to a college. It also considers the motivations of the young men and the requirements set by the colleges. It shows that the recruitment of Spanish friars relied on guidelines and templates that appointed commissioners who traveled to Spain on enlistment missions.
Writing Urban Crisis after Moynihan
Authors: Schryer Stephen
Published: September 2018

This chapter explores literary responses to the late 1960s crisis in participatory professionalism, provoked by the period’s race riots and by conservatives’ successful appropriation of liberal poverty discourse. The chapter focuses on two texts that address the Community Action Program: Joyce Carol Oates’s them and Tom Wolfe’s Radical Chic & Mau-Mauing the Flak Catchers. While these texts voice opposing political positions, both distrust white liberal efforts to speak for the ghetto, drawing on traditions of urban writing (naturalism and literary journalism) that resist the process imperative to break down barriers between author, audience, and lower-class subject matter. At the same time, both writers complicate their literary objectivity by incorporating aspects of the very participatory professionalism they seek to delimit.
Revolution in Brazil
Authors: Sarzynski Sarah
Published: September 2018

The first chapter introduces the main political and cultural actors engaged in the struggles in Northeastern Brazil during the Cold War. The chapter analyzes the origin stories of the different groups to show how certain versions that reinforced the trope of o Nordeste gained more attention in the mass media. The groups include the main rural social movements in the Northeast in the 1950s and 60s – the Ligas Camponesas, the Brazilian Communist Party Rural Syndicates, and the Catholic Church Federations; “Conservatives” including large landowners, the mainstream media, and state police; Brazilian development institutions such as SUDENE (Regional Development Agency); Brazilian regional and national politicians, U.S. journalists and government officials in the Northeast; and cultural movements and artists including filmmakers and popular poets. The chapter also outlines the regional, national, and international historical context of Northeastern Brazil in the 1950s and 1960s.
Introduction
Authors: Ellis Matthew H.
Published: September 2018

The Introduction lays out the book’s central argument about territoriality. I argue that Egypt constitutes an important case study given that it assumed more territorial definition as a modern nation-state in the late nineteenth century despite the absence of demarcated borders or clear-cut cartographic evidence. I seek to challenge prevailing historiography on territoriality that emphasizes the salience of border treaties and authoritative representational practices such as mapping, by showing instead the range of mechanisms that undergirded the projection of centralized territoriality in the nineteenth century. This argument has implications well beyond Egypt: territoriality as practiced—which we can glimpse by uncovering the lived experience of territoriality across the variegated domains of state space—was always a multilayered process of negotiation between an array of state and nonstate actors.
Accommodating Egyptian Sovereignty in Siwa
Authors: Ellis Matthew H.
Published: September 2018

This chapter takes us to Siwa—the westernmost oasis in Egypt, which acquired an almost mythic status as Egypt’s final frontier during the nineteenth century. The chapter zooms in on the Siwan political scene in the 1890s, when the Egyptian state intensified its efforts to unify its ruling authority across its various territorial domains. In contrast to the normative accounts of state centralization and local resistance, the chapter explores how a variety of local, nonstate actors—the Sanusiyya, foremost among them—played a crucial mediating role in the Egyptian government’s effort to exercise sovereignty over Siwa in this critical decade. The chapter illustrates this dynamic by focusing on the local negotiations of power between state and nonstate actors in Siwa that resulted in the formalization of the traditional Siwan elite’s customary authority.
The Limits of Ottoman Sovereignty in the Eastern Sahara
Authors: Ellis Matthew H.
Published: September 2018

This chapter documents the emergence of the Eastern Sahara as a contested borderland zone, marked by a nascent political rivalry between the Ottoman state and the “autonomous province” of Egypt. The view from the borderland allows us to glimpse fundamental limitations in the Ottoman exercise of sovereignty in the Eastern Sahara, particularly as Egypt acted increasingly as an independent centralizing state in its own right. Through its analysis of bedouin mobility across the invisible Egyptian-Libyan border, the chapter demonstrates that the tribes stood to gain a great deal by negotiating the onset of state power, alternately claiming or ignoring the existence of a border depending on their particular needs and interests at a given moment. Territorialization in the Eastern Sahara was thus a direct consequence of bedouin spatial practices, which threw into relief the vacuum in state authority at this marginal space between Ottoman Libyan and Egyptian sovereignty.
La charte de Venise en France : acteurs, réception, interprétations (1957-1976)
Authors: Houbart Claudine
Published: September 2018

Rédigée en 1964 et adoptée un an plus tard par le Conseil international des Monuments et des sites, qui en assu­rera la diffusion, la Charte de Venise reste aujourd’hui un document largement utilisé dans les milieux patrimoniaux. Cet article, qui se base principalement sur un dépouillement de la revue Les Monuments historiques de la France, complété de la consultation ponctuelle d’archives, s’attache à identifier la nature et la spécificité de l’apport français dans la rédaction et l’interprétation du document, durant la période allant du premier Congrès des architectes et te­chniciens des monuments historiques, à Paris, en 1957, au colloque organisé par ICOMOS France en 1976 pour faire le bilan de l’application de la charte dans les restaurations françaises. Après avoir identifié les principaux acteurs français impliquées dans les réflexions doctrinales internationales durant la période considérée, l’article examine, à travers une sélection de projets publiés dans la revue Les Monuments historiques de la France, deux des principes essentiels de la charte, en rupture avec l’héritage Viollet-le-Ducien : ce que Michel Parent appelle la « transparence des formes », et la lisibilité des interventions, la « marque de notre temps », prônée par la charte. Il conclut sur la contribution française à la révision du document, en 1977 : une entreprise qui échouera, mais aura à tout le moins suscité un bilan qui s’avère plutôt, pour la France, un nouveau point de départ pour les débats sur la restauration.
Une expérimentation précoce d’urbanisme patrimonial dans les années 1910-1920 : le « Casier archéologique et artistique de Paris et du département de la Seine »
Authors: Bassières Laurence
Published: September 2018

En France, les politiques économiques et les politiques urbaines sont régies par deux logiques séparés, il a fallu attendre les années 1960, avec l’approbation de la loi de Malraux sur les aires protégées, l’intégration des projets du patrimoine L’urbanisme a été adopté d’un point de vue législatif. Cependant, depuis la première moitié du XXe siècle, des expériences ont été menées dans ce sens à Paris et dans ses environs. Déjà en 1910, la Commission du Vieux Paris avec les architectes ont participé aux discussions autour de la nouvelle discipline de la planification urbaine, il est ensuite cherché à mettre en oeuvre une politique de protection du patrimoine qui pourrait être intégrée dans les projets de développement dans la ville. Cette tentative a servi de modèle pour le projet de constitution du «Registre Archéologique et Artistique de Paris et du Département de la Seine», inventaire architectural et urbain développé entre 1916 et 1928 qui a servi de base à l’inventaire patrimonial du Grand Paris. Organisé avec la collaboration des architectes et de la Commission du Vieux Paris, il a permis la mobilisation de divers acteurs qui ont aidé à l’évolution et à la constitution des politiques urbaines, et à consolider les inventaires de la ville et la manière dont ces travaux ont été entrepris.
Derecho a la ciudad y “Group Homes”: fomentar la inclusión social de personas con discapacidad intelectual
Authors: Correa-Montoya Lucas
Published: September 2018

El presente artículo desarrolla la idea que, desde un enfoque de derechos humanos, los group homes (viviendas colectivas para personas con discapacidad) pueden fomentar y asegurar el derecho a la ciudad para las personas con discapacidad intelectual. Lo anterior resulta posible debido a los servicios de la sección 1915(c) de la Ley de seguridad social en lo que a exención para hogares y servicios comunitarios se refiere, junto con algunas actividades y estrategias adicionales
¿Techos reflectivos o verdes? influencia sobre el microclima en ciudades de zonas áridas. Mendoza, Argentina*
Authors: Alchapar Noelia Liliana , Correa Érica Norma , Cantón María Alicia
Published: September 2018

El sellamiento intensivo de las superficies de la ciudad provocado por el crecimiento de las urbes modifica, entre otros factores, el balance térmico de los espacios urbanos y, en consecuencia, la temperatura del aire circundante y de las superficies de la envolvente urbano-edilicia. Para analizar los beneficios ambientales derivados de la implementación de tecnologías reflectivas y verdes aplicadas a las superficies de techos, se contrastó el comportamiento de la temperatura del aire y temperatura media radiante en tramas que incorporan techos reflectivos (R) y verdes (V). Mediante simulación, se evaluaron 32 escenarios que modifican su configuración morfológica y material con respecto a un caso base. La incorporación de tecnologías de techo reflectivas y verdes mejoran la habitabilidad de los espacios exteriores. Los escenarios con techo reflectivo disminuyen la temperatura de aire urbana hasta 1,6 K y los escenarios con techo verde hasta 2,1 K.
Automated Multi-User Analysis of Virtualized Voxel-Based Cam on Shared GPUs
Authors: Lynn Roby , Medrano Roberto Leo , Contis Didier , Tucker Tommy , Kurfess Thomas
Published: September 2018

Computer-aided manufacturing (CAM) software allows for the generation of toolpaths for computer numerical control (CNC) machine tools and enables the creation of sophisticated parts that would not otherwise be possible with conventional manual machining methods. Voxel-based CAM is a recent approach to toolpath planning that enables creation of paths for parts that would be difficult to create with traditional CAM software. However, the use of voxel-based CAM necessitates the presence of powerful hardware (specifically, graphics processing units) in order to perform the necessary computations for creating toolpaths. The concepts of virtualization and desktop-as-a-service offer a promising solution to this challenge, as they allow for many users to access computer hardware that is hosted on a single server. This work investigates the performance impact caused by multiple simultaneous users on voxel-based CAM deployed in a virtualized environment. The implementation of a Python application for multi-user simulation on the virtualized platform is described and timing results gathered from a sequence of simulations are presented and analyzed as the number of users is varied. The results from these simulations demonstrate consistent operational times for a low number of simultaneous users before a period of high performance variation due to resource sharing.
Coupled Predicting Surface Variation by Face Milling of Engine Block/Head
Authors: Liu Shun , Jin Sun , Zhang Xueping , Liu Changhui , Yang Fuyong , Chen Jiamin
Published: September 2018

Face milling commonly generates surface quality of roughness or variation, especially severe for the milling of large-scale components with complex surface geometry such as cylinder block, engine head, and valve body. Thus surface variation serves as an important indicator both for machining parameter selection and components’ service performance. Conversely the optimization of machining process is a vital objective to improve the surface quality and its service life of machined components. Many researchers have dedicated to the prediction of machined surface variation generated by face milling using numerical or experimental methods. However, the numerical methods based on finite element analysis (FEA) are good at predicting local deformation of workpiece under instantaneous milling force, particularly applied for online compensation in face milling. Whereas experimental methods can only be used to estimate whole surface variation through reverse correlation analysis of measured data and processing variables. Therefore, an efficient and comprehensive numerical model is highly desired for the prediction of surface variation of entire surface. This study proposes a coupled numerical simulation method, updating FE model literarily based on the integration of data from ABAQUS and MATLAB, to predict surface variation induced by the face milling of large-scale components with complex surfaces. Using the coupled model, the 3D variation of large-scale surface can be successfully simulated by considering face milling process including dynamic milling force, spiral curve of milling trajectory, and intermittently rotating contact characteristics. Surface variation is finally represented with point cloud from totally iterative FE analysis and verified by face milling experiment. Result shows that the new prediction method can simulate surface variation of complex components. Based on the verified model, a set of numerical analyses are conducted to evaluate the effects of local stiffness non-homogenization and milling force variation on machined surface variation. It demonstrates that surface variation with surface peaks and concaves is strongly correlated with local stiffness non-homogenization especially in feed direction. Thus the coupled prediction method provides a theoretical and efficient way to study surface variation induced by face milling of large-scale complex components.
Interaction of a Sliding Wedge and a Metallic Specimen With a Near-Surface Inhomogeneity
Authors: Salilkumar Vandana A. , Sundaram Narayan K.
Published: September 2018

The problem of a hard wedge sliding against a metal substrate has been studied extensively for its importance in tribo-plasticity and deformation processing. Here we explore the effect of introducing a single, near-surface plastic inhomogeneity (termed as a pseudograin) in a metal substrate using Lagrangian finite element (FE) analysis. The pseudograin is allowed to be softer or harder than the surrounding material. The effects of sliding parameters like the size and location of the pseudograin, friction and indenter geometry are also studied. Interestingly, the introduction of the pseudograin can lead to production of surface folds / self-contacts, and acutely-inclined, near-surface, crack-like features, which cannot be reproduced by homogeneous specimens. In fact, this tribosystem is phenomenologically very rich, despite differing from classical triboplastic systems of Challen, Oxley and Torrance only by way of the inhomogeneity. Despite its simplicity, the model replicates several experimentally observed features of surface folding, and is a minimal model to obtain folding in sliding. The occurrence of surface folds and concomitant residual surface damage points to the important role played by microstructure-related inhomogeneities in determining surface quality in deformation processing operations (e.g. repeated sliding to generate UFG surfaces) and is also a potentially new mode of sliding wear.
Electrical Signatures for Chemical Action at the Work Surface in an Oxyfuel Flame
Authors: Martin Christopher R. , Kinney Joseph , Matzik Andrew , Molina Jessica
Published: September 2018

An oxyfuel cutting torch was biased with a positive DC voltage relative to steel and copper work pieces, and ion currents were seen to flow due to ions generated chemically in the flame and at the work surface. A repeatable 150% rise in these currents occurs over steel at a surface temperature around 1050°C. Equally strong intermittent spikes appear over clean and corroded steel samples alike. They are are easily removed by a median value filter, and are believed to be due to small reacting particulates. Tests in which salt was deliberately deposited on the steel surface produces a signal similar in shape, but exaggerated in magnitude to those currents supposed to be from other surface impurities.
Edge Trimming of CFRP Composites Using Rotary Ultrasonic Machining: Effects of Ultrasonic Vibration
Authors: Wang Hui , Ning Fuda , Hu Yingbin , Li Yuanchen , Wang Xinlin , Cong Weilong
Published: September 2018

Carbon fiber reinforced plastic (CFRP) composites have many excellent properties, which make them be widely used in many applications. After demolding processes, CFRP composites still need additional machining processes to achieve final shape with desired tolerances. Edge trimming is the first machining process performed on composites after their molding processes. Because of carbon fibers’ abrasive properties as well as CFRPs’ properties of inhomogeneity and anisotropy, CFRPs are regarded as the difficult-to-cut materials. Many problems are generated in traditional machining processes. To reduce and solve the problems, edge trimming using rotary ultrasonic machining (RUM) is reported in this manuscript. This paper, for the first time, makes the comparisons on machining performance (cutting forces, torque, and surface roughness) between edge trimming processes with and without ultrasonic vibration assistance. To better understand effects of ultrasonic vibration on such a process, machining mechanisms are also obtained and analyzed. This paper will provide guides for RUM edge trimming of CFRP composites.
Printing of Microscale Nanotwinned Copper Interconnections Using Localized Pulsed Electrodeposition (L-PED)
Authors: Behroozfar Ali , Daryadel Soheil , Morsali S. Reza , Bernal Rodrigo A. , Minary-Jolandan Majid
Published: September 2018

Nanotwinned (nt) metals exhibit superior electrical and mechanical properties compared to their coarse-grained and nano-grained counterparts. They have a unique microstructure with grains that contain layered nanoscale twins divided by coherent twin boundaries (TBs). Since nanotwinned metals have low electrical resistivity and high resistance to electromigration, they are ideal materials for making nanowires, interconnections and switches. In this paper we show the possibility of making nanotwinned copper interconnections on a non-conductive substrate using a novel additive manufacturing technique called L-PED. Through this approach, microscale interconnections can be directly printed on the substrate in environmental conditions and without post processing.
Digital Feed-Forward Control of Gas Mixture With High-Speed Valve Switching
Authors: Martin Christopher R. , Batzel Todd D.
Published: September 2018

To address a need for digital gas mixture control, this paper presents a valve design for digital gas flow rate control without a feedback measurement. This design uses a transonic nozzle to regulate a constant flow rate with partial pressure recovery and a pulse-width modulation scheme to actuate flow rate without needing precise location of a throttle body. Experimental results from a prototype are presented showing linear variation of flow with respect to duty cycle and switching frequency consistent with the valve’s theory of operation. Outliers are especially prominant as frequency is varied, and are believed to be due to acoustic effects in the supply line.
Ceramic Additive Manufacturing Using VAT Photopolymerization
Authors: Diptanshu  , Young Erik , Ma Chao , Obeidat Suleiman , Pang Bo , Kang Nick
Published: September 2018

The popularity of additive manufacturing for producing porous bio-ceramics using vat photopolymerization in the recent years has gained a lot of impetus due to its high resolution and low surface roughness. In this study, a commercial vat polymerization printer (Nobel Superfine, XYZprinting) was used to create green bodies using a ceramic suspension consisting of 10 vol.% of alumina particles in a photopolymerizable resin. Four different sizes of cubical green bodies were printed out. They were subjected to thermal processing which included de-binding to get rid of the polymer and thereafter sintering for joining of the ceramic particles. The porosity percentage of the four different sizes were measured and compared. The lowest porosity was observed in the smallest cubes (5 mm). It was found to be 43.3%. There was an increase in the porosity of the sintered parts for the larger cubes (10, 15 and 20 mm). However, the difference in the porosity among these sizes was not significant and ranged from 61.5% to 65.2%. The compressive testing of the samples showed that the strength of the 5-mm cube was the maximum among all samples and the compressive strength decreased as the size of the samples increased. These ceramic materials of various densities are of great interest for biomedical applications.
Boundary Slope Control in Topology Optimization for Additive Manufacturing
Authors: Wang Cunfu , Qian Xiaoping , Gerstler William D. , Shubrooks Jeff
Published: September 2018

The paper studies how to control boundary slope of optimized parts in density-based topology optimization for additive manufacturing (AM). Boundary slope of a part affects the amount of support structure required during its fabrication by additive processes. Boundary slope also has direct relation with the resulting surface roughness from the AM processes, which in turn affects the heat transfer efficiency. By constraining the minimal boundary slope, support structures can be eliminated or reduced for AM, and thus material and post-processing costs are reduced; by constraining the maximal boundary slope, high surface roughness can be attained, and thus the heat transfer efficiency is increased. In this paper, the boundary slope is controlled through a constraint between the density gradient and the given build direction. This allows us to explicitly control the boundary slope through density gradient in the density-based topology optimization approach. We control the boundary slope through a single global constraint. Numerical examples on heat conduction problem, and coupled 2D and 3D thermoelastic problems demonstrate the effectiveness and efficiency of the proposed formulation in controlling boundary slopes for additive manufacturing.
An Analysis of Microstructure and Microhardness Distribution in Underwater Wet Welding of 304L Austenitic Stainless Steel to Low Alloy Steel 16Mn
Authors: Li HongLiang , Liu Duo , Wang Zhi , Guo Ning , Feng JiCai
Published: September 2018

In this study, underwater wet welding of 304L austenitic stainless steel to 16Mn low alloy steel was carried out using self-shielded flux-cored wires at a water depth of 0.3 m. The welds were produced using commercially obtained ER308 filler and specially developed nickel-based tubular wire. Microstructure and microhardness of wet welded joints have been particularly analyzed. The interface between austenitic weld metal and ferritic base metal was also discussed in detail.

A robust weld of 304L/16Mn joint could be achieved by FCAW process using nickel-based tubular wire. Commercially obtained ER308 consumables failed to acquire sound welded joints due to large amount of slag remained in the groove. Ni-based weld metal was fully austenitic with well-developed columnar sub-grains while ER308 weld metal consisted of d-ferrite with different morphologies in the austenitic matrix. Type II boundary existed between austenitic weld metal and ferritic base metal. Compared to ER308 weld metal, Ni-based weld metal possessed the ability to be diluted by 16Mn base metal.

Maximum hardness values in wet welding appeared in coarse-grained heat affected zone instead of transition zone for both consumables. Austenitic stainless steel welded joints exhibited high microhardness in the transition zone of 16Mn side, which was strongly diluted by ferritic base metal.
Building Block-Based Assembly of Scalable Metallic Lattices
Authors: Jenett Benjamin , Gershenfeld Neil , Guerrier Paul
Published: September 2018

We describe a method for the manufacturing of metallic lattices with tunable properties through the reversible assembly of building block elements, which we call discrete metal lattice assembly (DMLA). These structures can have sub-millimeter scale features on millimeter scale parts used to assemble structures spanning tens of centimeters, comparable to those currently made with Direct Metal Laser Sintering (DMLS). However, unlike traditional additive manufacturing (AM) methods, the use of discrete assembly affords a number of benefits, such as extensible, incremental construction and being repairable and reconfigurable. We show this method results in large scale (tens of centimeters), ultralight (<10 kg/m3 effective density) lattices which are currently not possible with state of the art additive manufacturing techniques. The lattice geometry used here is a combination of two geometries with quadratic property scaling, resulting in a novel lattice with sub-quadratic scaling.
Shape Memory Behavior of Carbon Composites With Functional Interlayer
Authors: Santo L. , Iorio L. , Tedde G. M. , Quadrini F.
Published: September 2018

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.
Molecular Dynamics Simulation Study of Ultrasonic Powder Consolidation Process
Authors: James Sagil , Rajanna Prashanth
Published: September 2018

An Ultrasonic Powder Consolidation is an additive manufacturing technique that utilizes high-frequency vibrations to consolidate micro/nano powder materials to fully dense and near to net-shaped parts. Unlike traditional powder consolidation techniques such as sintering, shock wave-based and pressure-based processes, the consolidation during Ultrasonic Powder Consolidation process happens at relatively low temperatures and pressures within few seconds or less. Ultrasonic Powder Consolidation process presents several inherent advantages including low power consumption, low cost and zero thermal stresses on the consolidated parts. Experimental studies have shown that Ultrasonic Powder Consolidation process is capable of successfully consolidating powders of metals and metal-matrix composites. While Ultrasonic Powder Consolidation process promises several potential applications, the mechanism of bond formation between the consolidated metal powders is not completely understood. This research uses Molecular Dynamics simulation technique to investigate the underlying bond formation and consolidation mechanisms involved in Ultrasonic Powder Consolidation process. The research also explores the effects of critical process parameters including vibration frequency, amplitude and initial temperature on the quality of the consolidated part. The study found that high-frequency vibrations cause high interfacial stresses resulting in acoustic softening and high plastic deformation of the nanoparticles. The study revealed that the overall atomistic temperature does not exceed the melting point of the material. The study also found that the vibration amplitude and frequency played a significant role in the consolidation process. Finally, the simulation study showed that the high-frequency vibration leads to large plastic deformations at ultra-high shear strain rates causing the interfacial atoms to interlock with each other resulting in high densification and consolidation. The results of this study would augment the ongoing experimental studies on Ultrasonic Powder Consolidation process which would help realize the promised potentials of this low temperature – low-pressure consolidation technique.
Texture Development and Mechanical Response in Microscale Reverse Extrusion of Copper
Authors: Zhang Bin , Song Yooseob , Voyiadjis George , Juul Kristian , Shao Shuai , Meng Wen Jin
Published: September 2018

Axisymmetric reverse extrusion experiments were conducted on annealed Cu rod specimens to form cup-shaped structures with sidewall thicknesses ranging from ∼400 μm down to ∼25 μm. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) were used to examine the changes in Cu grain morphology and texture as a result of the forming operation. Pole figure (PF) and orientation distribution function (ODF) analysis of EBSD data showed the presence of the same texture components in the present small scale metal forming experiments as those observed previously in macroscale sheet metal rolling. Extrusion force – punch displacement curves were measured as a function of extruded cup sidewall thickness. The present work illustrates materials characteristics in small scale metal forming, and suggests directions of future work for bringing improved correspondence between experimentation and modeling for metal micro forming.
Numerical Investigation of Dislocation Density and Grain Size Evolution in Orthogonal Cutting of Pure Titanium Using Microgrooved Cutting Tools
Authors: Wu Han , Ma J. , Lei Shuting
Published: September 2018

In this paper, a coupled Eulerian-Lagrangian (CEL) finite element model is developed based on FEM software package Abaqus to solve the evolution of the dislocation density and grain size simultaneously. This validated CEL FEM model is then utilized to investigate the effects of microgrooved cutting tools on the evolution of dislocation density and grain size in orthogonal cutting of commercially pure titanium (CP Ti). Microgrooved cutting tools are cemented carbide (WC/Co) cutting inserts with microgrooves on the rake face. The effects of microgroove width and microgroove convex width are investigated in terms of cutting force, chip morphology, dislocation density, and grain size. It is concluded that this CEL FEM model can capture the essential features of orthogonal cutting of commercially pure titanium (CP Ti) alloy using microgrooved cutting tools. It is also concluded that microgroove width and convex width have substantial influence on the dislocation density profiles and grain size profiles along the depth from the machined surface and the tool-chip interface, respectively. This conclusion provides insightful guidance for altering the surface integrity of the machined surface based on needs.
Optimizing Bi-Criteria Permutation Flow Shop Scheduling Problem by Improved NSGA III
Authors: Meng Ronghua , Rao Yunqing , Luo Qiang
Published: September 2018

This paper addresses a bi-objective distribution permutation flow shop scheduling problem (FSP) with setup times aiming to minimize the makespan and the total tardiness. It is very difficult to obtain an optimal solution by using traditional approaches in reasonable computational time. This paper presents an appropriate non-dominated sorting Genetic Algorithm III based on the reference point. The NEH strategy is applied into the generation of the initial solution set. To validate the performance of the NEH strategy improved NSGA III (NNSGA III) on solution quality and diversity level, various test problems are carried out. Three algorithms, including NSGA II, NEH strategy improved NSGA II(NNSGA II) and NNSGA III are utilized to solve this FSP. Experimental results suggest that the proposed NNSGA III outperforms the other algorithms on the Inverse Generation Distance metric, and the distribution of Pareto solutions are improved excellently.
Fabrication of Knee Prostheses by Means of SLM: Process and Functional Characterization
Authors: Liverani Erica , Conconi Michele , Sancisi Nicola , Lutey Adrian H. A. , Ascari Alessandro , Fortunato Alessandro
Published: September 2018

This article presents manufacturing of exemplary knee prostheses using selective laser melting (SLM) technology. All phases of design and production are considered, from acquisition of the STL build file to optimization of process parameters, printing and post-build heat treatments. Geometric differences are acquired and compared with a 3D scanner.
Influence of NC Program Quality and Geometric Errors Onto S-Shape Machining Accuracy
Authors: Sato Ryuta , Shirase Keiichi , Ihara Yukitoshi
Published: September 2018

S-shaped machining test is proposed for ISO standard to evaluate the motion accuracy of five-axis machining centers. However, it have not been investigated that which factor mainly influences the quality of the finished S-shape workpieces. This study focuses on the influence of the quality of NC program and geometric errors of rotary axes onto the quality of finished surface. Actual cutting tests and simulations are carried out to the investigation. As the results, it is clarified that the tolerance of NC program has a great influence onto the quality. It is also clarified that the geometric errors have great influences onto the quality. However, it is difficult to evaluate the influence of each geometric error because all geometric errors make glitches at the same point on the machined surface. It can be concluded that the proposed S-shape machining test can be used as the total demonstration of the machining techniques.
Fractal Pattern Recognition of Image Profiles for Manufacturing Process Monitoring and Control
Authors: Imani Farhad , Yao Bing , Chen Ruimin , Rao Prahalada , Yang Hui
Published: September 2018

Nowadays manufacturing industry faces increasing demands to customize products according to personal needs. This trend leads to a proliferation of complex product designs. To cope with this complexity, manufacturing systems are equipped with advanced sensing capabilities. However, traditional statistical process control methods are not concerned with the stream of in-process imaging data. Also, very little has been done to investigate nonlinearity, irregularity, and inhomogeneity in image stream collected from manufacturing processes. This paper presents the multifractal spectrum and lacunarity measures to characterize irregular and inhomogeneous patterns of image profiles, as well as detect the hidden dynamics of the underlying manufacturing process. Experimental studies show that the proposed method not only effectively characterizes the surface finishes for quality control of ultra-precision machining but also provides an effective model to link process parameters with fractal characteristics of in-process images acquired from additive manufacturing. This, in turn, will allow a swift response to processes changes and consequently reduce the number of defective products. The proposed fractal method has strong potentials to be applied for process monitoring and control in a variety of domains such as ultra-precision machining, additive manufacturing, and biomanufacturing.
Mechanical Behavior of LDPE/MWCNT Composites After Fatigue and Cryogenic Treatment
Authors: Fetecau Catalin , Stan Felicia , Timotin Petru , Stanciu Nicoleta V. , Rosculet Razvan T.
Published: September 2018

In this study, the effects of fatigue and cryogenic treatments on the mechanical behavior of low-density polyethylene/ multi-walled carbon nanotube (LDPE/MWCNT) composites have been investigated. Injection-molded samples of LDPE/MWCNT composite with different MWCNT weight fractions (0.1–5.0 wt.%) were subjected to cryogenic and fatigue treatments under different testing conditions, and the residual-mechanical properties were investigated. To monitor the fatigue damage, additionally, the electrical conductivity was measured. The results show that the LDPE/MWCNT composites retained good residual-mechanical properties after fatigue (more than 85% of its initial Young modulus) and cryogenic (more than 75% of its initial tensile strength and Young’s modulus) treatment. For the LDPE/MWCNT composites, the electrically conductive nanotube network can be efficiently maintained up to 25 000 fatigue cycles.