bluuebunny/crossref_metadata_2025 huggingface dataset:
A Virtual Blind Cane Using a Line Laser-Based Vision System and an Inertial Measurement Unit
Authors: Dang Quoc , Chee Youngjoon , Pham Duy , Suh Young
Published: January 2016

A virtual blind cane system for indoor application, including a camera, a line laser and an inertial measurement unit (IMU), is proposed in this paper. Working as a blind cane, the proposed system helps a blind person find the type of obstacle and the distance to it. The distance from the user to the obstacle is estimated by extracting the laser coordinate points on the obstacle, as well as tracking the system pointing angle. The paper provides a simple method to classify the obstacle’s type by analyzing the laser intersection histogram. Real experimental results are presented to show the validity and accuracy of the proposed system.
Assessing Air Quality in Turkey: A Proposed, Air Quality Index
Authors: Büke Tayfun , Köne Aylin
Published: January 2016

The annual air quality indices are aimed at better taking into account of long-term exposure to air pollution. This type of indices offer decision-makers condensed environmental information for performance monitoring, policy progress evaluation, benchmarking comparisons, and decision-making. This paper evaluates the air quality of eight Turkish cities in view of the European Union (EU) norms. The proposed index aggregates concentrations of three air pollutants, namely sulphur dioxide, nitrogen dioxide, and particulate matter and it is built by using 2014 data from 20 air quality monitoring stations. According to the results obtained from the calculation, the EU standards were exceeded at 14 stations, while at six stations the situation is better than the norms. These results indicate that Turkey has failed in fulfilling the European air quality standards.
Incobotulinum Toxin-A Improves Post-Surgical and Post-Radiation Pain in Cancer Patients
Authors: Rostami Rezvan , Mittal Shivam , Radmand Reza , Jabbari Bahman
Published: January 2016

Cancer patients who undergo surgery or radiation can develop persistent focal pain at the site of radiation or surgery. Twelve patients who had surgery or radiation for local cancer and failed at least two analgesic medications for pain control were prospectively enrolled in a research protocol. Patients were injected up to 100 units of incobotulinum toxin A (IncoA) intramuscularly or subcutaneously depending on the type and location of pain (muscle cramp or neuropathic pain). Two patients passed away, one dropped out due to a skin reaction and another patient could not return for the follow up due to his poor general condition. All remaining 8 subjects (Age 31–70, 4 female) demonstrated significant improvement of Visual Analog Scale (VAS) (3 to 9 degrees, average 3.9 degrees) and reported significant satisfaction in Patients’ Global Impression of Change scale (PGIC) (7 out of 8 reported the pain as much improved). Three of the 8 patients reported significant improvement of quality of life.
La pensée géographique en France au XIXe siècle : continuité ou rupture ?
Authors: Broc Numa
Published: January 2016

Some aspects of the french geographical thought during the 19th century. — The status and evolution of geography in France during the first half of the 19th century cannot be compared to its briliant burst of the 18th. Then it is not considered as a science but as an utilitarian knowledge : this is the reason why it does not appear in Ampere's or Comte's classifications. Many geographers, such as Balbi or Daunou, intend to protect the so said pure geography, from intercourses with geology or statistics when Cortambert attempts to associate it with the other sciences related to nature observation. Levasseur considers geography as a science of chain interrelations ; but it turns to an encyclopedic quest dominated by the determinist hypothesis which appears in Schrader and Dubois. Another disputed problem was related to the geographical divisions — natural or political — as they were discussed by Malte-Brun and Balbi. Regions were defined as hydrographie catchment areas when Elie de Beaumont stressed the importance of geological features. After 1870 the expressions of natural region and pays were favoured by Drapeyron, Berlioux, Levasseur and Auerbach and magnified by Lapparent — the main source and master of Vidal de La Blache — in spite of Dubois's opposition.
Les deux Cerdagnes. Exemple de transformations économiques asymétriques de part et d'autre de la frontière des Pyrénées
Authors: Tulla Antoni F.
Published: January 2016

L'auteur insiste sur les phénomènes de différenciation spatiale enregistrés en Cerdagne de part et d'autre de la frontière pyrénéenne (densités et structures par âge de la population agglomérée, etc.) et les met en relation avec l'intégration à des moments différents de chacun des compartiments séparés de cette région jadis homogène aux formations sociales et aux modes de production économiques des deux États constitués de part et d'autre des Pyrénées.
Limited Functional Effects of Subacute Syngeneic Bone Marrow Stromal Cell Transplantation after Rat Spinal Cord Contusion Injury
Authors: Sandner Beatrice , Ciatipis Mareva , Motsch Melanie , Soljanik Irina , Weidner Norbert , Blesch Armin
Published: January 2016

Cell transplantation might be one means to improve motor, sensory, or autonomic recovery after traumatic spinal cord injury (SCI). Among the different cell types evaluated to date, bone marrow stromal cells (BMSCs) have received considerable interest due to their potential neuroprotective properties. However, uncertainty exists whether the efficacy of BMSCs after intraspinal transplantation justifies an invasive procedure. In the present study, we analyzed the effect of syngeneic BMSC transplantation following a moderate to severe rat spinal cord injury. Adult Fischer 344 rats underwent a T9 contusion injury (200 kDy) followed by grafting of GFP-expressing BMSCs 3 days postinjury. Animals receiving a contusion injury without cellular grafts or an injury followed by grafts of syngeneic GFP-expressing fibroblasts served as control. Eight weeks post-transplantation, BMSC-grafted animals showed only a minor effect in one measure of sensorimotor recovery, no significant differences in tissue sparing, and no changes in the recovery of bladder function compared to both control groups in urodynamic measurements. Both cell types survived in the lesion site with fibroblasts displaying a larger graft volume. Thus, contrary to some reports using allogeneic or xenogeneic transplants, subacute intraparenchymal grafting of syngeneic BMSCs has only a minor effect on functional recovery.
Cryopreserved Ex Vivo-Expanded Allogeneic Myeloid Progenitor Cell Product Protects Neutropenic Mice from a Lethal Fungal Infection
Authors: Domen Jos , Christensen Julie L. , Gille Daphne , Smith-Berdan Stephanie , Fong Timothy , Brown Janice M. Y. , Sedello Anna K.
Published: January 2016

Severe neutropenia induced by chemotherapy or conditioning for hematopoietic cell transplantation often results in morbidity and mortality due to infection by opportunistic pathogens. A system has been developed to generate ex vivo-expanded mouse myeloid progenitor cells (mMPCs) that produce functional neutrophils in vivo upon transplantation in a pathogen challenge model. It has previously been demonstrated that transplantation of large numbers of freshly isolated myeloid progenitors from a single donor provides survival benefit in radiation-induced neutropenic mice. In the present work, an ex vivo-expanded and cryopreserved mMPC product generated from an allogeneic donor pool retains protective activity in vivo in a lethal fungal infection model. Infusion of the allogeneic pooled mMPC product is effective in preventing death from invasive Aspergillus fumigatus in neutropenic animals, and protection is dose dependent. Cell progeny from the mMPC product is detected in the bone marrow, spleen, blood, and liver by flow cytometry 1 week postinfusion but is no longer evident in most animals 4 weeks posttransplant. In this model, the ex vivo-generated pooled allogeneic mMPC product (i) expands and differentiates in vivo; (ii) is functional and prevents death from invasive fungal infection; and (iii) does not permanently engraft or cause allosensitization. These data suggest that an analogous ex vivo-expanded human myeloid progenitor cell product may be an effective off-the-shelf bridging therapy for the infectious complications that develop during hematopoietic recovery following hematopoietic cell transplantation or intensive chemotherapy.
Peripheral Nerve Regeneration through Hydrogel-Enriched Chitosan Conduits Containing Engineered Schwann Cells for Drug Delivery
Authors: Meyer Cora , Wrobel Sandra , Raimondo Stefania , Rochkind Shimon , Heimann Claudia , Shahar Abraham , Ziv-Polat Ofra , Geuna Stefano , Grothe Claudia , Haastert-Talini Kirsten
Published: January 2016

Critical length nerve defects in the rat sciatic nerve model were reconstructed with chitosan nerve guides filled with Schwann cells (SCs) containing hydrogel. The transplanted SCs were naive or had been genetically modified to overexpress neurotrophic factors, thus providing a cellular neurotrophic factor delivery system. Prior to the assessment in vivo, in vitro studies evaluating the properties of engineered SCs overexpressing glial cell line-derived neurotrophic factor (GDNF) or fibroblast growth factor 2 (FGF-218kDa) demonstrated their neurite outgrowth inductive bioactivity for sympathetic PC-12 cells as well as for dissociated dorsal root ganglion cell drop cultures. SCs within NVR-hydrogel, which is mainly composed of hyaluronic acid and laminin, were delivered into the lumen of chitosan hollow conduits with a 5% degree of acetylation. The viability and neurotrophic factor production by engineered SCs within NVR-Gel inside the chitosan nerve guides was further demonstrated in vitro. In vivo we studied the outcome of peripheral nerve regeneration after reconstruction of 15-mm nerve gaps with either chitosan/NVR-Gel/SCs composite nerve guides or autologous nerve grafts (ANGs). While ANGs did guarantee for functional sensory and motor regeneration in 100% of the animals, delivery of NVR-Gel into the chitosan nerve guides obviously impaired sufficient axonal outgrowth. This obstacle was overcome to a remarkable extent when the NVR-Gel was enriched with FGF-218kDa overexpressing SCs.
Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies
Authors: Raffaini Giuseppina , Ganazzoli Fabio , Mazzaglia Antonino
Published: January 2016

Chemically modified cyclodextrins carrying both hydrophobic and hydrophilic substituents may form supramolecular aggregates or nanostructures of great interest. These systems have been usually investigated and characterized in water for their potential use as nanocarriers for drug delivery, but they can also aggregate in apolar solvents, as shown in the present paper through atomistic molecular dynamics simulations and dynamic light scattering measurements. The simulations, carried out with a large number of molecules in vacuo adopting an unbiased bottom-up approach, suggest the formation of bidimensional structures with characteristic length scales of the order of 10 nm, although some of these sizes are possibly affected by the assumed periodicity of the simulation cell, in particular at longer lengths. In any case, these nanostructures are stable at least from the kinetic viewpoint for relatively long times thanks to the large number of intermolecular interactions of dipolar and dispersive nature. The dynamic light scattering experiments indicate the presence of aggregates with a hydrodynamic radius of the order of 80 nm and a relatively modest polydispersity, even though smaller nanometer-sized aggregates cannot be fully ruled out. Taken together, these simulation and experimental results indicate that amphiphilically modified cyclodextrins do also form large-scale nanoaggregates even in apolar solvents.
Resolution of morphology-based taxonomic delusions: Acrocordiella, Basiseptospora, Blogiascospora, Clypeosphaeria, Hymenopleella, Lepteutypa, Pseudapiospora, Requienella, Seiridium and Strickeria
Authors: Jaklitsch W.M. , Gardiennet A. , Voglmayr H.
Published: January 2016

Fresh material, type studies and molecular phylogeny were used to clarify phylogenetic relationships of the nine genera Acrocordiella, Blogiascospora, Clypeosphaeria, Hymenopleella, Lepteutypa, Pseudapiospora, Requienella, Seiridium
and Strickeria. At first sight, some of these genera do not seem to have much in common, but all were found to belong to the Xylariales, based on their generic types. Thus, the most peculiar finding is the phylogenetic affinity of the genera Acrocordiella, Requienella
and Strickeria, which had been classified in the Dothideomycetes or Eurotiomycetes, to the Xylariales. Acrocordiella and Requienella are closely related but distinct genera of the Requienellaceae. Although their ascospores are similar to those
of Lepteutypa, phylogenetic analyses do not reveal a particularly close relationship. The generic type of Lepteutypa, L. fuckelii, belongs to the Amphisphaeriaceae. Lepteutypa sambuci is newly described. Hymenopleella is recognised as phylogenetically
distinct from Lepteutypa, and Hymenopleella hippophaëicola is proposed as new name for its generic type, Sphaeria (= Lepteutypa) hippophaës. Clypeosphaeria uniseptata is combined in Lepteutypa. No asexual morphs have been detected
in species of Lepteutypa. Pseudomassaria fallax, unrelated to the generic type, P. chondrospora, is transferred to the new genus Basiseptospora, the genus Pseudapiospora is revived for P. corni, and Pseudomassaria carolinensis is combined in
Beltraniella (Beltraniaceae). The family Clypeosphaeriaceae is discontinued, because the generic type of Clypeosphaeria, C. mamillana, is a member of the Xylariaceae. The genus Seiridium, of which the sexual morph Blogiascospora is confirmed,
is unrelated to Lepteutypa, as is Lepteutypa cupressi. The taxonomy of the cypress canker agents is discussed. The family Sporocadaceae is revived for a large clade of the Xylariales that contains Hymenopleella, Seiridium and Strickeria among
a number of other genera. Neotypes are proposed for Massaria fuckelii and Sphaeria hippophaës. Didymella vexata, Seiridium marginatum, Sphaeria corni, Sphaeria hippophaës, Sphaeria seminuda are epitypified, Apiosporina fallax,
Massaria occulta, Sphaeria mamillana and Strickeria kochii are lecto- and epitypified. We also provide DNA data for Broomella vitalbae, Cainia desmazieri and Creosphaeria sassafras.
An Integrated-Empirical Logistics Perspective on Supply Chain Innovation and Firm Performance
Authors: Mandal Santanu
Published: January 2016

Supply chains need to innovate constantly for maintaining their position in the marketplace and also to fight uncertainties. Hence firms are focusing on strategies for developing supply chain innovation. The current investigation adds to this emerging regime through investigating the influence of logistics capabilities viz. demand management capability, supply management capability, information management capability and coordination capability on supply chain innovation through logistics integration. Further, supply chain innovation helps a firm to sustain its position in the market place through generation and launching of new products and services. Accordingly, the influence of supply chain innovation on firm performance is also investigated. Data is collected from logistics, purchasing and supply chain professionals working in different industries in India. The findings based on 169 responses largely support our proposed relationships.
What Forms University? An Integrated Model from Syria
Authors: Khalifa Bayan , Mahmoud Ali
Published: January 2016

This study aims at developing and empirically testing an integrated model incorporating the factors that form university image in Syria. The study used a quantitative survey of students at Syrian universities. A pre-test of the questionnaire was undertaken using a convenient sample of 40 students. Thereafter, a sample of 259 students was used to test the model using structural equation modeling. The findings suggest word of mouth and faculty-individualized attention, one of service quality dimensions, as the antecedents of university image. Moreover, the findings reveal a positive effect of faculty-individualized attention and support staff helpfulness, as service quality dimensions, on student satisfaction. It is also found that student satisfaction positively affect word of mouth. This study is expected to help Syrian universities understand the key factors contributing to university image formation, and, therefore, strengthen their positions in the market. This study comes to be one of the first studies that attempt to understand how university image is formed.
Assessment of Intellectual Capital in Joint-Stock Companies
Authors: Tamošiūnienė Rima , Survilaitė Simona
Published: January 2016

The evaluation of intellectual capital factors is an essential part for the management of joint-stock companies. Many authors indicate that successful intellectual capital management increases value added in joint-stock companies. Nevertheless, intellectual capital is a complex and challenging concept as there is still no clear guidance, what the intellectual capital features and its structural parts are. Theoretical research revealed that scientists accentuate various intellectual capital parts depending basically on the type of their research, on the level of the research (micro, mezzo, macro), variables they selected to investigate and similar. This research paper gives an insight what drivers can be increasing value added in joint-stock companies.
Erich Przywara et Edith Stein : de l’analogie de l’être à une analogie de la personne
Authors: Tommasi Francesco Valerio
Published: January 2016

La question de l’analogie – fondamentale pour toute la néoscolastique, de Gilson à Maritain – trouva sa consécration en 1932 dans le fameux Analogia entis d’Erich Przywara. À la suite de l’influence de Przywara, l’analogie a eu un rôle décisif aussi dans la pensée d’Edith Stein. Mais en décrivant la dialectique phénoménologique entre être fini et être éternel Stein confère à l’analogie de l’être une tournure que l’on peut qualifier de « personnelle ». Il s’agit du rapport entre deux « je suis » : le « je suis » humain et créatural et le « je suis » divin. L’analogia entis originelle est donc pour Stein le rapport entre deux personnes.
La vajilla de los días de fiesta: cerámica ática en una casa de finales del siglo V a.C. de Ullastret
Authors: Picazo Gurina Marina
Published: January 2016

A partir del estudio de un grupo numeroso de vasos áticos de Ullastret, se propone en este trabajo una reflexión sobre las elecciones que el mundo indígena peninsular era capaz de hacer respecto a la cerámica fina de origen griego, especialmente ática, de finales del siglo V y la primera mitad del siglo IV a.C. La construcción a lo largo del tiempo de una ‘vajilla de fiesta’ relacionada con el consumo colectivo de vino nos introduce en el tema de la influencia de las pautas culturales griegas en la aristocracia ibérica.
Cuantificación en cerámica, ¿ejercicio especulativo o ejercicio hipotético? Las cerámicas ibéricas y púnicas en la Iliberri del siglo IV a.C. procedentes del depósito de la calle Zacatín (Granada)
Authors: Adroher Auroux Andrés María , Sánchez Moreno Amparo , De la Torre Castellano Inmaculada
Published: January 2016

La excavación en 1999 de una fosa rellena con abundante material datado en la primera mitad del siglo IV a.C. supone un importante avance en el conocimiento de la arqueología ibérica en el oppidum de Iliberri, pues amplia el ámbito periurbano a la relación tan estrecha que mantiene la ciudad con su territorio a través de la imagen del rio Darro. En este trabajo se presenta el estudio del material ibérico y púnico procedente de ese contexto, con interesantes aportaciones acerca de los sistemas de clasificación y cuantificación cerámica en arqueología protohistórica.
Fundar la casa: prácticas rituales y espacio doméstico en el oppidum ibérico de El Puig d’Alcoi (Alacant)
Authors: Grau Mira Ignasi , Amorós López Iván , De Miguel Ibáñez María Paz , Iborra Eres Pilar , Segura Martí Josep Maria
Published: January 2016

En este trabajo presentamos las prácticas rituales identificadas en el oppidum ibérico de El Puig d’Alcoi, en el área central de la Contestania, al norte de la actual provincia de Alicante. Se trata de dos depósitos en la base de viviendas del poblado de los ss. v y iv a.C., en los que se enterraron restos de banquetes y sacrificios de animales, con la inhumación de un perinatal en uno de ellos. Los interpretamos como rituales de fundación de viviendas y se analizan en relación con la vida doméstica desarrollada en el transcurso de la ocupación del poblado, en concreto con los procesos de construcción-reconstrucción de las casas y con las relaciones sociales de la comunidad que habitó El Puig d’Alcoi.
El Cerro de los Santos: paisaje, negociación social y ritualidad entre el mundo ibérico y el hispano
Authors: García Cardiel Jorge
Published: January 2016

La ubicación del santuario ibérico del Cerro de los Santos junto a una de las principales vías de comunicación del sureste meseteño y en el centro de una comarca desprovista de núcleos urbanos de cierta entidad permite subrayar en este artículo su uso continuado como santuario de paso, lugar sacro y seguro al que los caminantes podrían acogerse para pernoctar bajo la protección de la divinidad. La creación de una statio en el enclave en época romana y su dedicación a la diosa Pales no son sino argumentos ulteriores en este sentido. Se identifican además contextos materiales domésticos, distintos de los espacios de culto bien conocidos del santuario, relacionables con esta otra actividad.
Figurillas de encapuchados hispanorromanos: Definición, clasificación e interpretación
Authors: Salido Domínguez Javier , Rodríguez Ceballos Mariano
Published: January 2016

Las figurillas de encapuchados o cucullati fueron frecuentes en el mundo romano. El característico cucullus fue usado tanto por hombres de baja consideración social como por personas pudientes que deseaban no ser reconocidos; y con esta capucha y manto-capucha, dotados de un significado especial, fueron también representados genii, seres divinos y otras pequeñas divinidades, así como figuraciones que servían como ahuyentadores de espíritus y símbolos protectores. En el ámbito de la antigua Hispania estas representaciones han pasado bastante desapercibidas, lo que obedece a un problema de publicación más que de una ausencia en el registro arqueológico. La revisión historiográfica de las esculturillas de cucullati de terracota y bronce, documentadas hasta el momento en la Península Ibérica, nos permite analizar su procedencia, características técnicas, aportando hipótesis sobre su significado en su contexto arqueológico.
El lugar de visigodos y omeyas en la historiografía de los siglos XIX y XX. Aportaciones a un debate sobre continuidad y ruptura
Authors: Salvatierra Cuenca Vicente
Published: January 2016

Este texto pretende analizar la evolución durante los siglos XIX-XX de algunos paradigmas en la división histórica entre la Antigüedad y la Alta Edad Media y su repercusión en la Arqueología española. De forma especial se describirá el modo y el momento en que se introdujo el concepto de Antigüedad tardía que desplaza a los anteriores paradigmas. Asímismo se trata de analizar si los elementos de continuidad y proceso conectados al mismo afectan a los orígenes de al-Andalus, discutiéndose si existió un corte brusco y tajante a partir de la invasión árabe y bereber.
Applying Security to a Big Stream Cloud Architecture for the Internet of Things
Authors: Belli Laura , Cirani Simone , Davoli Luca , Ferrari Gianluigi , Melegari Lorenzo , Picone Marco
Published: January 2016

The Internet of Things (IoT) is expected to interconnect billions (around 50 by 2020) of heterogeneous sensor/actuator-equipped devices denoted as “Smart Objects” (SOs), characterized by constrained resources in terms of memory, processing, and communication reliability. Several IoT applications have real-time and low-latency requirements and must rely on architectures specifically designed to manage gigantic streams of information (in terms of number of data sources and transmission data rate). We refer to “Big Stream” as the paradigm which best fits the selected IoT scenario, in contrast to the traditional “Big Data” concept, which does not consider real-time constraints. Moreover, there are many security concerns related to IoT devices and to the Cloud. In this paper, we analyze security aspects in a novel Cloud architecture for Big Stream applications, which efficiently handles Big Stream data through a Graph-based platform and delivers processed data to consumers, with low latency. The authors detail each module defined in the system architecture, describing all refinements required to make the platform able to secure large data streams. An experimentation is also conducted in order to evaluate the performance of the proposed architecture when integrating security mechanisms.
A Collaboration Model
Authors: Kermani Meriem , Boufaida Mahmoud
Published: January 2016

The dynamic formation of a consortium, combining the most adequate set of competencies and resources to satisfy the needs of each new situation sounds indeed as a very appealing approach. However, reaching a rapid ‘alignment' among a diverse group of heterogeneous entities is not simple and may require a considerable time to achieve. In this collaborative context, the integration of industrial partners depends strongly on the ability to use a collaborative model to interact efficiently. In this paper, the authors propose a model to tackle this point according to the fact that the partners of the collaboration may change. They propose the development of an approach to achieve a dynamic inter-company collaboration. In this cooperation mode, many companies share their resources, data services and processes. These companies have their own mechanisms and applications, which are heterogeneous. First, the authors define a framework to establish this kind of collaboration. The purpose of this solution is to keep the company architecture and to ask the mediator for playing an intermediary role between companies. Then, the authors propose a service selection mechanism based on the agent technology and on the decision tree paradigm. They present an offline composition service process. Finally, they illustrate their solution with an example of treating an emergency case to show the feasibility of the proposed model.
Internet Based Collaboration Tools
Authors: Wahl Lori , Kitchel Allen
Published: January 2016

This structured literature review examines the digital tools used to facilitate distance collaboration and the available research relative to the use of those tools. The purpose of this paper was to contribute to a better understanding of Internet based professional collaboration tools, their features and benefits, and best research based professional practices. The authors examined 33 refereed or peer reviewed articles published from 2002 to 2015 that addressed the use of Web-based digital tools to support professional collaboration. Authors who are considered experts in the areas of virtual communities, digital collaboration, social psychology and technology and who publish in other forms were also included in the paper. In addition to providing a definition, a description and available research for each tool type, the Fit-Viability Model () is presented as part of this paper to guide digital collaborators in digital tool selection. The review and synthesis of the literature suggest an emerging need for a range of knowledge of Internet-based professional collaboration tools. Important elements of this knowledge include an understanding of the types of tools available and their features, limitations, and use. These insights empower digital collaborators with the ability to choose an appropriate and efficient tool for the collaborative project.
Milling Force and Machining Deformation in Mirror Milling of Aircraft Skin
Authors: Bao Yan , Dong Zhi Gang , Kang Ren Ke , Li Zhao , Yuan Yi Chu
Published: January 2016

Machining the aircraft skin, using CNC milling to replace the traditional chemical milling, is a trend owning to the great pollution of the chemical milling to the environment. Based on the instantaneous rigidity force hypothesis, a milling force model for mirror milling of aircraft skin was proposed, which was validated by the milling force measurement during mirror milling experiments. A FEM model was established to calculate the deformation of the aluminum plate in mirror milling. The effects of the supporting position on the deformation was analyzed.
Molecular Dynamics Simulation of a Cutting Method by Making Use of Localized Hydrostatic Pressure
Authors: Shimizu Jun , Uezaki Keito , Zhou Li Bo , Yamamoto Takeyuki , Onuki Teppei , Ojima Hirotaka
Published: January 2016

This study aims to develop a cutting method, which enables to generate a localized hydrostatic pressure field in the vicinity of cutting zone in order to improve the machined surface integrity without causing unnecessary plastic deformation. In the previous work, a molecular dynamics simulation was performed using a newly developed cutting tool equipped with a planer jig with a rectangular hole for the cutting chip elimination, and it was confirmed that the developed cutting tool has advantages in giving a relatively high-hydrostatic stress field in the vicinity of the cutting zone and in suppressing the burr formation. In this report, further molecular dynamics simulation was performed in order to clarify the influence of jig shape on the cutting phenomena and machined surface integrity. As a result, it is found that a cutting tool of which front and side except for the rectangular hole are covered by the planer jig is the most advantageous for supplying high hydrostatic pressure and suppressing burr formation.
Influence of Tool Shape on Cutting Characteristics in Ultra-Precision Cutting of Al-Mg Alloys
Authors: Iida Tomohiro , Maeda Yukio , Hirase Daisuke , Motoyoshi Tatsuo , Tanaka Hideaki , Kato Kazuya , Yazawa Takanori
Published: January 2016

In this study, we investigated ultra-precision cutting technology of aluminum alloys for polygon mirrors made of Al-Mg Alloys. It is necessary to improve the geometric surface roughness achieved in the mirror cutting of Al-Mg alloys and remove tear-out marks and scratch marks that occur during the cutting process. Therefore, we investigated the cutting edge shape using 2 types of straight diamond tools and 2 types of round tools to decrease the surface defects in the ultra-precision cutting of Al-Mg alloys. As a result, a double-facet tool can achieved a good machined surface roughness and reduce the cutting force and the scratch marks compared with other tools.
Proposal of Tilt Helical Milling Method for Hole Creation of Carbon Fiber Reinforced Plastic (CFRP)
Authors: Wu Yong Bo , Wang Qiang , Nomura Mitsuyoshi
Published: January 2016

Carbon fiber reinforced plastic (CFRP) are used for various aircraft structural components because of their superior mechanical and physical properties such as high specific strength, high specific stiffness, etc. In order for CFRP materials to be used in aircraft structures or machine elements, high quality holes must be created on them efficiently. However, it is difficult for conventional methods such as drilling, helical milling and so on to meet the requirements. Therefore, this study proposes a novel method for creating holes on CFRP products. This method is just performed by tilting the workpiece at a certain angle on the basis of conventional helical milling (CHM) and hence called tilt helical milling (THM). In this paper, the processing principle of the THM is described in detail at first. An experimental apparatus is then constructed by installing a work holding unit produced in house onto a CNC milling machine. Finally, experiments are carried out on the apparatus. The obtained experimental results demonstrated that the THM is capable of creating holes on CFRP with lower burrs and chippings formation compared with those by CHM. By this new method, high quality holes could be obtained with high efficiency compared with conventional methods.
Temperature Field Study of Hole Drilling in Kevlar Composites
Authors: Bao Yong Jie , Zhang Yi Ni , Gao Hang , Liu Xue Shu
Published: January 2016

The cutting heat, during the process of drilling fiber reinforced resin matrix composites, has a significant effect on the quality and the tool wear. In this paper, based on the homogenization hypothesis of the material and the finite difference method, a temperature field model for drilling unidirectional Kevlar composites was developed. During the drilling process, the heat source formed by cutting edge and chisel edge can be seen as a conical heat source. The results show that the temperature field distribution is ellipse away from the drilling zone with the longer axis paralleling to the fiber direction and changes close to the drilling zone.
Effect of Diamond Coating on Drilling Force and Temperature during High Speed Micro Drilling of Bone
Authors: Zhao Zi Han , Wen Liang , Song Jin Bang , Yu De Dong , Chen Ming , Shen Steve G.F.
Published: January 2016

Bone drilling commonly exists in clinical practice and the heat and force generated by the drilling process has a huge impact on the surgery effect and the recovery of patients. High speed drilling, proved to have less injury and be more efficient when compared to the traditional low speed drilling, is considered to be the development direction of bone drilling-related surgeries. In order to make a further study of the controlling of the heat and force during the bone drilling process, the experiment designed to examine the influence of the diamond coating has been conducted and the result indicates that the diamond coating generally has little influence on the drilling force, however, it can increase the drilling temperature to a certain extent which indicates that the diamond coating is not suitable to apply to bone drills under the conditions of the conducted experiments. The result of this research could be of some help to the development of new kinds of medical drills.
Chip Formation during Precision Cutting of Metallic Glass
Authors: Kodama Hiroyuki , Okuda Koichi , Inada Tsukasa
Published: January 2016

The chip formation mechanism during precision cutting of metallic glass (Zr55Cu30Ni5Al10 at%) was investigated around the glass transition temperature (673 K). Orthogonal cutting of metallic glass are conducted on a fly-cutting machine at various cutting speeds. The new surface of the chips was slightly shiny while the free surface exhibited lamellar slip structure. The cutting temperature was a proportional to the cutting ratio and chip shear angle. The surface integrity worsened with an increased flow of cutting chip due to an increase in the cutting speed. An increase in the cutting temperature caused the chips formation to change from flow type chips to discontinuous chips. When the cutting speed exceeded 300 m/min, the shear angle increased while the shear pitch of the chips decreased. It appears that when the cutting temperature exceeded the glass transition temperature, the strength of the metallic glass decreased and the ductility mode changed due to viscous flow.
FEM Stress Analysis of Interfacial Failure of Multilayered Thin Film Structures in Nanoscratching
Authors: Kang Cheng Wei , Huang Han
Published: January 2016

Precision grinding of a multilayered thin film solar panel is recognized as the bottleneck in its manufacturing process. A primary challenge is the significantly high stress induced at the thin film interfaces during grinding. Such stress concentration can result in interfacial delamination between two dissimilar materials and thus device malfunction. This study used a finite element modelling analysis to understand the stress evolution of the multilayer thin film structure during a single grit scratching that simulates the individual interaction between abrasive grits and work materials in grinding. The results demonstrated that significant tensile and shear stresses were formed at interfaces during scratching, which could be traced back to the experimental evidence obtained from the nanoscratching process. The maximum stresses undertaken by the interfaces were simulated.
Research on Grinding Force of Zirconia Internal Grinding with Resin Bond Diamond Wheel
Authors: Wang He , Zhang Ke , Wu Yu Hou , Song Hong
Published: January 2016

The zirconia parts are limited by machined surface quality. The grinding force is one of the most important parameters of grinding and has effects on surface quality. The MK2710 grinder and resin bond diamond wheels were used in zirconia grinding. The grinding force was obtained by Kistler dynamometer. The paper focused on wheel speed and grain size on grinding force, and examined the surface by SEM. The research results indicated that decreasing the grain size, the grinding force increased and the surface quality improved, and increasing wheel speed could decrease grinding force to improve grinding surface quality. The results can improve zirconia ceramic parts surface quality and promote application.
Dental Grinding of Lithium Disilicate Ceramic Prostheses Using High-Speed Rotary Cutting Instruments in In Vitro Oral Adjusting
Authors: Ren Hai Tao , Song Xiao Fei , Zhang Xiao Feng
Published: January 2016

Oral adjusting of ceramic prostheses involving abrasive machining using dental high-speed rotary cutting instruments is a central process in restorative dentistry, because this process affects not only restorative quality but also patients’ comfort. However, the dental grinding process, especially dental grinding of high-strength ceramic prostheses, is less understood in clinical dentistry. This paper presents dental grinding of an innovative high-strength lithium disilicate ceramic in in vitro oral adjusting regime using a dental high-speed electric handpiece and diamond burs. The dental abrasive machining characteristics were quantitatively evaluated in terms of normal and tangential forces, force ratio, and specific grinding energy as functions of clinically relevant dental grinding variables including depth of cut and feed rate and feed direction of burs. The results showed that the dental tangential and normal forces and specific grinding energy exhibited significant dependences on depth of cut, feed rate and direction of burs, but revealed significantly small scales compared to engineering machining regime. Clinical implication was given that down grinding undoubtedly reduced the abrasive adjusting forces to relieve patients’ discomfort in oral regime. Moreover, dentists must be cautious in dental abrasive adjusting of the lithium disilicate ceramic prostheses at or beyond the specific material removal rate of 2.4 mm3/min due to significantly large forces and vibrations.
A Study on Ultrasonic Torsional Vibration-Assisted Abrasive Waterjet Polishing of Ceramic Materials
Authors: Wang Yong , Zhu Hong Tao , Huang Chuan Zhen , Wang Jun , Yao Peng
Published: January 2016

Abrasive waterjet machining is considered as a promising technique in hard-brittle material polishing. In this paper, The ultrasonic torsional vibration is considered to apply on the workpiece to improve the abrasive waterjet polishing quality and efficiency. The process parameters in the ultrasonic torsional vibration-assisted abrasive waterjet polishing are optimized. The ultrasonic torsional vibration in the role of the abrasive waterjet polishing is investigated. The results show that the application of ultrasonic torsional vibration can effect of abrasive particle movement and increase the critical depth of the ceramic materials.
Nano-Precision Polishing of Oxygen-Free Copper Using MCF (Magnetic Compound Fluid) Slurry
Authors: Wang You Liang , Wu Yong Bo , Nomura Mitsuyoshi
Published: January 2016

Oxygen-free copper (OFC) is a popular material used for molds/dies in injection molding of plastic lens because of its high ductility, strong impact strength and good thermal conductivity. nanoprecision polishing is essential as the final process in its fabrication. For this purpose, a novel polishing method using magnetic compound fluid (MCF) slurry was proposed. In this article, the construction of an experimental rig to realize the proposed method was described at first. Then the effects of process parameters including MCF slurry composition, workpiece oscillation parameter f/Ap-p and clearance Δ between workpiece and MCF carrier on work-surface roughness and material removal were experimentally investigated. As a result, nanoprecision surface finish of OFC was successfully attained by polishing with MCF slurry and the optimum process parameters (f/Ap-p=30 Hz/4mm, Δ=0.6 mm with an MCF slurry (45wt.% of CIP, 12 wt.% of Al2O3 grain, 3 wt.% of α-cellulose, 40 wt.% of MF) for obtaining the smoothest work-surface were determined.
Investigation of Abrasive Super Finishing under Various Paths with a 5-Axis Closed-Link Compact Robot and Fine Diamond Stone
Authors: Liu Tao , Kure Takashi , Hirogaki Toshiki , Aoyama Eiichi , Liu Yu Dong
Published: January 2016

To reduce the environmental impact of abrasive polishing, we investigated fixed-abrasive polishing using a compact robot. We used a five-joint closed-link compact robot with a fine diamond stone on the main axis to polish a glass plate and measured the polishing pressure and polishing force. We analyzed the stick-slip vibration of a glass polishing motion due to the low stiffness of the robot arm and estimated the influence of relative speed changes on the friction coefficient between the glass plate and the abrasive stone. We also used various paths to polish the workpiece to examine the characteristics of the polishing equipment. Based on the results, we proposed a method that can estimate a workpiece's surface roughness based on the friction coefficient. Using the compact robot and a fine diamond stone, the workpiece's surface roughness decreased and polishing processes on the glass plate were more stable.
Grinding for Microstructural Functional Surface
Authors: Chen Xun , Li Hao Lin , Cao Hao Yang , Wharton James , Allanson David , Hu Zhi Qing
Published: January 2016

Structural textural surfaces are those surfaces that have designed feature intended to give specific functional performance. In the last few decades, the understanding of structured surface texture, particularly at a micro and nanometre scale, has played a fundamental role in the development of many advanced applications. After a brief review of current manufacturing methods for textural surface, this paper examines the surface creation during grinding by analysing the kinematics of grinding and associated wheel dressing processes. It has been demonstrated that the features of structural surface can be determined by carefully selected dressing and grinding conditions. The grinding speed ratio between workpiece and wheel is an important factor in determine the layout of the structural pattern generated on the workpiece. The grinding depth not only affects the structural feature depth but also the length and width of the surface structure. The uniformity and repeatability of actual ground feature shape is influenced by the arbitrary nature of distribution of grinding abrasives.
Coupled Thermal-Mechanical Analysis of CO2 Laser Irradiation on Fused Silica
Authors: Li Run Qiang , Yao Peng , Meng Hao , Wang Jun , Zhang Ke , Huang Chuan Zhen , Zou Bin , Liu Han Lian
Published: January 2016

To grind fused silica in ductile mode, it was proposed to repair surface and subsurface micro cracks of fused silica by CO2 laser irradiation. However, excessive residual stress remains on the surface because the melt fused silica on the surface quenches in air. It causes the critical depth of cut for ductile grinding fused silica to be smaller than 0.2μm. To investigate the distribution of the residual stress and look for an optimal manner of irradiation to control residual tensile stress, a numerical model of was built for simulating the dynamic behavior of fused silica when irradiated by CO2 laser. Laser energy absorption, heat transmission, viscoelastic behavior of fused silica and thermally induced stress were considered in the numerical simulation. The results show how the residual stress is formed and distributed. We found that an appropriate control of the temperature field as a function of time and position in the laser process is the key to reduce the residual stress. Therefore, three kinds of processes were proposed to reduce residual tensile stress on the surface of fused silica introduced by laser irradiation. The residual stress distributions of these three processes were compared by numerical analysis to decide a better method of laser irradiation.
Grinding Technology of Cylindrical Surface with Protrusion
Authors: Kato Kazuya , Maeda Yukio , Tanaka Hideaki
Published: January 2016

Cylindrical parts with a protrusion are expected to be used in the components of consumer electronics and automotive products. The machining efficiency of these parts is very low, making them difficult to be mass-produced. The aim of our present work is to develop a highly accurate and highly efficient grinding process for a cylindrical surface with a protrusion. This paper describes the results of experiments using a straight cup-shaped grinding wheel. The following conclusions can be drawn. (1) To prevent uneven wear of the grinding wheel, an oscillation operation is necessary during the grinding process. (2) By employing the straight cup-shaped grinding wheel, the grinding process is realized with the aim of achieving the following: high machining accuracy, roundness below 3 μm, straightness below 2 μm, and surface roughness below 2 μmRzjis.
The Dynamic Mechanical Properties of Oxygen Free Copper under the Impact Load
Authors: Liu Qing Feng , Wang Ning Chang , Yan Lan , Jiang Feng , Huang Hui
Published: January 2016

The dynamic mechanical properties of oxygen free copper has been tested under the different strain rate (4700s-1~21000s-1) at the room temperature by split Hopkinson pressure bar (SHPB), the true stress-true strain curves has been obtained. Power-Law constitutive model and Johnson-Cook constitutive model have been built to fit the experimental result from SHPB test of oxygen free copper, meanwhile, the constitutive model can be applied to the simulation analysis of cutting process. The results show that the oxygen free copper is sensitive to the strain rate. In addition, the Johnson-Cook constitutive model predicts the plastic flow stress of the oxygen free copper more accurately than the Power-Law constitutive model at the high strain rate.
Effect of Carbide Orientation on Sliding Wear Behaviour of High Chromium Cast Iron
Authors: Jiang Zheng Yi , Gao Xing Jian , Wei Dong Bin , Li Sheng Li , Zhang Hong Mei , Xu Jian Zhong , Wu Di , Jiao Si Hai
Published: January 2016

The effect of carbide orientation on the dry sliding wear behaviour of high chromium cast iron was studied by pin-on-disc type wear tests at room temperature. The carbide anisotropy was achieved by thermomechanical treatments at temperatures of 950 and 1150 °C. By cladding with low carbon steel, the brittle high chromium cast iron was hot compressed severely with crack free. The thermomechanical treatments not only change the carbide orientation, but also increase the volume fraction of carbides. Due to the long axis of carbide rods is parallel to the wear surface, the high chromium cast iron treated at 1150 °C has a superior wear resistance than the as-cast one, in which the long axis of carbides is perpendicular to the wear surface. For the high chromium cast iron treated at 950 °C, high volume fraction of carbide pits accelerates the wear rate significantly even though it has a similar carbide orientation as the sample treated at 1150 °C. The observations on wear tracks reveal that the ferrous matrix can be protected better from abrasion when the high chromium cast iron was treated at 1150 °C.