bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Analysis of Crack-Like Defects Influence on the Open Cell Ceramic Foam Tensile Strength
Authors: Ševeček Oldřich , Majer Zdeněk , Marcián Petr , Bertolla Luca , Kotoul Michal
Published: August 2018

This work deals with a computational analysis and quantification of the influence of processing (primarily crack-like) defects of various amount on the (tensile) strength of open cell ceramic foam structures. This information is essential e.g. for application of these materials in the mechanically loaded application, where a design with certain reliability to operating conditions is required. The analysed ceramic foam structures are composed of both regular and irregular cells and crack-like defects (pre-cracked struts) are simulated inside them. The foam structure is modelled using a 3D FE beam element based model created by utilization of the Voronoi tessellation technique. The tensile strength upon presence of various amount of pre-cracked struts is analysed based upon an iterative FE simulation on whose base the critical failure force leading to specimen fracture is determined. The performed parametric study relates the tensile strength of the foam structure to the amount of initial defects. With increasing amount of these defects, the foam strength decreases by approximately 30% with every 10% of broken struts. This information can be directly used for a fast estimation of the foam tensile strength if the fraction of broken struts to the intact ones is known (e.g. from a microscopic analysis).
Effect of Water Immersion on Interfacial Strength of a Metal/Epoxy Joint
Authors: Yamazaki Yasuhiro , Kudo Katsu
Published: August 2018

Metal/resin joints have been widely used for automotive, electrical device and others. The degradation of interfacial strength of the joints through the effects of moisture is one of the important deterioration mechanisms in their structure applications. In this study, the interfacial strength of an aluminum-alloy/epoxy-resin joint was evaluated by the indentation test using of the instrumented indentation machine developed by ourselves. The in-situ observations of delamination cracking were carried out during the indentation test. The interfacial fracture toughness of the joint was evaluated from the relationship between the indentation load and the crack length. The effect of immersion into service water on the evaluated interfacial strength of the joint was discussed.
Thermo-Mechanical Analysis of the Exhaust Manifold of a High Performance Turbocharged Engine
Authors: Lorenzini Mariano , Giacopini Matteo , Barbieri Saverio Giulio
Published: August 2018

This contribution presents a methodology for the structural analysis of the exhaust manifold of an internal combustion engine. In particular, the thermal loading and the related thermal fatigue damage mechanism are addressed. The component investigated is a melted exhaust manifold which includes the turbine involute. The complex geometry of the component derives from the project constrains in terms of engine performance and sound targets. Finite Element simulations are performed to obtain a virtual approval of the component geometry, in advance with respect to the component manufacturing. The Finite Element analysis accurately follow the experimental approval procedure which considers different warming and rapid cooling cycles to mimic typical engine operating conditions. Two particular aspects of the developed numerical methodology are described in details: a) the elasto-plastic behaviour of the material at high temperatures; b) a damage criterion for thermal fatigue. Following the Ferrari expertise derived by previous experimental and numerical analysis of other exhaust manifolds, the increase of the equivalent plastic strain registered for a single thermal cycle (delta PEEQ) is firstly adopted as a damage criterion. The methodology reveals itself to be well correlated with the experimental evidences thus limiting the number of tests necessary for the component approval.
Experimental Verification of Dents Effect on the Structural Integrity of Pipeline DN 300
Authors: Kec Jan , Černý Ivo , Luštinec Jan , Poupa Miloslav , Pavelková Romana , Janovec Jiří
Published: August 2018

The stress-strain behaviour of two dents with different depth and shape during the fatigue pressure and burst pressure test is described. The internal inspection carried out on a high-pressure line DN 300 revealed the presence of two dents. Then, the part containing the dents was dug out, removed from operation and the pressure tests were carried out. The stress-strain behaviour was measured with help of nine strain gauges placed on the external pipe surface in the vicinity of dents. The fatigue pressure test simulated fluctuation of pressure, temperature and landslides during operation. During the fatigue pressure test, the profile changes of dents were observed; on the other hand, no fracture occurred. It followed the pressure burst test, the results of which enabled to determine the limit state, burst pressure and position of fracture.
Effect of High Temperature Environment on the Tensile Strength of Carbon Fiber/Highly Heat Resistant Polyamide Resin
Authors: Tanaka Kazuto , Takei Toshiaki , Katayama Tsutao
Published: August 2018

Carbon Fiber Reinforced Thermoplastics (CFRTP) are expected to be used in the automobile parts. Since the automobile parts can be subjected to the temperature up to 120 °C, the mechanical properties of CFRTP under high temperature environment should be evaluated. Although Polynonamethyleneterephthalaamide (PA9T) is an expected candidate as the highly heat resistant resin to be used for the matrix of CFRTP, the mechanical properties of CFRTP using PA9T under high temperature have not been clarified yet. In this study, the effects of molding conditions on the mechanical properties of CFRTP using PA9T were evaluated and its tensile strength under high temperature environment was measured.
Guided-Waves in a Low Velocity Impacted Composite Winglet
Authors: de Luca A. , Perfetto Donato , Petrone Giuseppe , de Fenza A. , Caputo F.
Published: August 2018

Airworthiness authorities require that composite materials in primary structures must be undamaged all in-service life long, resulting in an oversizing of structural components and in a general increasing of weight.
To allow structures working in presence of damages but showing an acceptable residual strength, in recent years a significant interest has been pointed out in the capability of ultrasonic guided waves as candidate tool for Structural Health Monitoring (SHM) of composites. The continuous assessment of the structural integrity, that can be accomplished by means of SHM systems, would provide, in fact, a less-conservative design and significant benefits in repair operations.
In this work, a description of two numerical techniques based on Finite Element Method (FEM) for the simulation of Lamb wave propagation in a damaged Glass Fibre Reinforced Polymer composite winglet is presented. The interaction between damage and guided-waves has been investigated under two central frequencies: 100 kHz and 150 kHz. Root Mean Square Deviation Damage Index has been used to compare the baseline signals (achieved under the pristine configuration) and the respective signals achieved under the impacted/damaged one. Numerical models have been assessed against an experimental tests campaign.
Convergence of the BEM Solution Applied to the CCFFM for LEBIM
Authors: Muñoz-Reja M. , Távara L. , Mantič Vladislav
Published: August 2018

A procedure based on the Linear Elastic Brittle Interface Model (LEBIM) combined with the Coupled Criterion of Finite Fracture Mechanics (CCFFM) is successfully implemented in a 2D Boundary Element Method (BEM) code. In the original LEBIM formulation, the values of the interface strength, fracture toughness and stiffness are dependent on each other. Therefore, for a large interface stiffness, when the elastic interface tends to a perfect (infinitely stiff) interface, LEBIM is not able to properly characterize the crack propagation. The use of the CCFFM applied to LEBIM, with both the stress and energy criteria imposed as independent fracture conditions, allows to uncouple the interface fracture toughness and strength, obtaining realistic predictions for crack propagation even for stiff interfaces. This code is successfully applied to the problem of debond onset and growth in the pull push test. A benchmark problem is solved, focusing on the convergence of the load-displacement curve and crack-tip solution for h-refinements of BE meshes.
Mixed-Mode Stress Intensity Factors for Tubes under Pure Torsion Loading
Authors: G. Diaz Jorge , Marques Luiz Fernando Nazaré , Guzmán Rolando Enrique
Published: August 2018

Although it seems like a common load-geometry configuration, there is neither an analytical nor a numerical solution for Stress Intensity Factors (SIF) in cracked tubes under pure torsion. Standards such as API 579, BS 7910 or handbooks do not present such case. There is plenty of solutions based on FEM or weight functions calculations for an extensive load-geometry combinations, but not for tubes under pure torsion. This paper shows curves of KI, KII, and KIII for through-wall cracks obtained with ANSYS simulations for slim tubes, under pure torsion with a rounded horizontal slit, numerically calculated via J-integral. Additionally KI, KII, and KIII are calculated using relative displacement between two points along the crack lips using Linear Elastic Fracture Mechanics (LEFM) formulations for Crack Tip Opening Displacement (COD) and Crack Tip Sliding Displacement (CTSD). Results are compared with experimentally measured SIF using the Digital Image Correlation (DIC) technique for fatigued-growth cracks reported in literature.
Analysis of the Analytical and Numerical Studies for Crack Widening in Lamellar Metal-Ceramic Composites
Authors: Piat Romana , Happ Pascal A.
Published: August 2018

Metal-ceramic composites offer many advantages over monolithic metals and their alloys such as high specific stiffness, strength and good thermal properties. In this paper, stress fields in a single-domain sample of metal-ceramic composite containing multiple cracks in the ceramic layer are investigated. In our previous studies the cracked microstructure for different stage of damage is modeled by analytical and computational approaches. In this paper the assumptions of the analytical model were verified using FE-models for different crack widening.
Cutting of a Thick Glass Plate by Using Hot Wire
Authors: Miyashita Yukio , Kurabe Yohei , Hiromoto Taro , Otsuka Yuchi
Published: August 2018

A thick glass plate was cut by using hot wire. Crack growing was stopped when wire temperature was low. Ligament length decreased with increase in temperature of hot wire and full-cutting was achieved at the temperature of 650°C. The center region in the thickness direction seemed to propagate earlier compared to surfaces regions when the crack propagation was stopped. Finite element thermal stress analysis was carried out. According to distribution of thermal stress inside a glass plate, higher stress was generated in the bottom region at the beginning of the process but occurred in the center region in the later stage as matching with the experimental result.
Stress Sensitivity of the T(0,1) Mode Velocity for Cylindrical Waveguides
Authors: Quiroga Mendez Jabid E. , González-Estrada Octavio Andrés , Ordonez Yesid Rueda
Published: August 2018

In this paper, the stress influence in the guided wave velocity of the fundamentaltorsional mode is presented. Two analytical models, based on the Acoustoelasticity effect, tocompute the fundamental torsional mode velocity propagating in a specimen subject to anaxial stress are studied. These models are obtained due to the relation between the T(0, 1)guided wave velocity and the bulk shear velocity. The analytical models to calculate the guidedwave velocity are functions of the stress, second and third order elastic constants. A series ofaxial stress levels applied to a cylindrical waveguide is investigated with numerical simulations(Finite Elements) to estimate variations of the T(0, 1) guided wave velocity. This analysisprovides a criterion to evaluate the practical implementation of a stress monitoring schemebased on velocity variations of the fundamental torsional mode.
Measuring Wear in a Fretting Test with a Confocal Microscope
Authors: Jordano G. , Navarro Carlos , Vázquez Jesús , Domínguez Jaime
Published: August 2018

Wear has been analyzed in several fretting fatigue tests with spherical contact performed on Al 7075 T651. The contact zone leaves a circular scar on the surface, which is easily detected because of the damage. Inside the contact zone, and almost concentric, another circular region called the stick zone can be distinguished. The annulus around it is called the sliding zone. The latter appears clearly damaged by wear and oxidation. The objective of this paper is to measure the size of these zones and their position, measure the wear in the sliding zone and establish a relation with the stresses at the contact. This has been done using a confocal microscope which gives a map of the surface: depth at each position. Given that the scar does not appear as an ideal circumference, the images have gone through a process of digital processing in order to obtain the geometric characteristics. Finally, the experimental data is combined with the analytical calculations through Archard wear model where a material parameter is calculated at each point in the sliding zone. It can be observed that despite the very different pressures and sliding distances in this zone, the material wear parameter is almost constant and similar to the ones in standard tests.
An Innovative Secondary Bonding of Sensors to Composite Structures for SHM Application
Authors: Yue Nan , Sharif Khodaei Zahra , Aliabadi M.H.
Published: August 2018

A novel procedure for installation of PZT sensors on composites is developed. The procedure is shown, through extensive tests, to be reliable, repeatable and repairable. The integrity of the bonded sensors are assessed following the RTCA DO-160 Environmental conditions and test procedures for airborne equipment. The developed bonding film has been tested on both thermoset and thermoplastic coupons and compared co-cured and secondary bonded sensors with epoxy.
On the Thickness Dependence of ILTS in Curved Composite Laminates
Authors: Zumaquero Patricia Lucía , Justo Jesús , Graciani Enrique
Published: August 2018

A test campaign has been carried out to determine the interlaminar tensile strength (ILTS) in AS4/8552 composite laminates with different thicknesses, following AITM 1-0069 and ASTM D6415/D6415M-06a standards. Results show that L-shaped samples with low thicknesses present lower values of the ILTS. Numerical finite element (FE) models of the samples have been carried out and the results of the numerical analyses have been compared with the experimental measurements, showing that a loss of stiffness has taken place in the samples. Optical inspection of the samples has shown up a significant misalignment of the fibers in the curved part that justifies the loss of stiffness in all samples and the loss of strength in the thinner samples.
An Effective Impact Detection Method for Composite Curved Panel
Authors: Seno Aldyandra Hami , Sharif Khodaei Zahra , Aliabadi M.H.
Published: August 2018

ANNs are only accurate for the scope of the given training data which is not suitable for real life impact localisation due to the large range of possible impact variation. Impact data was collected for a variation of impact cases (angle, mass and energy) on a sensorized curved composite panel. From observation of the obtained data, a robust signal Time of Arrival (TOA) extraction method is proposed using a Normalised Smooth Envelope Threshold (NSET) which is a modification of the currently known Normalised Threshold (NT) method. Two ANNs were trained using TOA extracted with the NT and NSET method from a baseline case and tested with TOA extracted from cases having added variation of impact condition. The results show that the proposed NSET method results in more accurate results for impact cases different to the training case and thus allows for only a single impact training case to accurately predict cases with multiple variation. This enhances the applicability of ANNs for impact localisation in real life conditions.
Failure Analysis of the Restraining System of the Directional Rudder of an MD80 Aircraft
Authors: Coronado J. , Mendoza K. , Martinez M.
Published: August 2018

The directional rudder travel of an aircraft must be restricted as the speed in flight increases, this in order to decrease its sensitivity, thus avoiding maneuverability problems or overloads that could result in a break in the vertical stabilizer and cause an accident. aerial. The aircraft MD 80 have a system of restriction of the route of the directional rudder, whose main component, the hook, is the piece in charge of stopping the movement as it is introduced in the piston rod of the hydraulic cylinder that governs the movement of the rudder. In this work, the causes of the hook fractured that left the directional mechanism out of service is analyzed. In order to carry out the work, the manufacturing material of the piece was first characterized, doing the analysis of its microstructure and alloying elements, it was obtained that it has the typical characteristics of an AISI 4340 steel. Subsequently, the loads acting on the piece in service condition and the initiation of the crack route were determined. Then, the fatigue study was carried out through simulations using the finite element method. The results were that the piece failed due fatigue due to a superficial defect.
Not Playing the Game: Negative Opinions about Online Dating and Video Gaming among Non-Participants
Authors: Marc Max
Published: August 2018

Per prior research, both online dating and video gaming are strongly associated with real and virtual relationship formation among participants. Yet this exploratory research study finds that eighty five percent of internet users have never participated in online dating and fifty percent of survey respondents have never participated in video gaming. This study uses data from a large nationally representative survey on online dating and video gaming in the U.S.The study employs the sociotechnical and the uses-and-gratifications theoretical perspectives to emphasize the role of information technology in shaping and framing relationships, and the importance of understanding individual context in the use of such technologies. The study investigates the characteristics of individuals who harbor negative opinions about online dating and video gaming despite having never participated in these activities. Opinions include: “Online dating is more dangerous than other ways of meeting people”, “People who use online dating sites are desperate”, “Video games are a waste of time,” and “Video games portray women poorly.”This research finds that among those who have never participated in online dating, more negative opinions about online dating are associated with a higher frequency of internet usage, a more conservative political orientation and lower educational and income levels. Here, current relationship status did not have a significant association with negative opinions among non-participants. With respect to video gaming, among those who have never participated in video gaming, more negative opinions about video gaming are associated with higher age and a more conservative political orientation. Additionally, among non-participants, the opinion that people who play violent video games are more likely to be violent themselves is associated with higher age, lower income level, and being female. The large body of work that has focused on online dating and video games as drivers of relationships has focused on participants in these activities. There is scarce research on non-participants even though non-participants comprise at least half the population. By focusing on these ignored groups, this study advances broader understanding of the individual and societal contexts under which individuals choose to not participate in these activities that are known to be associated with relationship outcomes. Non-participation is related to technophobia and the findings from this study will help broaden understanding of that phenomenon.
Immersive Storytelling in 360-Degree Videos: An Analysis of Interplay Between Narrative and Technical Immersion
Authors: Elmezeny Ahmed , Edenhofer Nina , Wimmer Jeffrey
Published: August 2018

Three-hundred-and-sixty-degree videos are an innovative video format, and due to various narrative and technical aspects, they allow audiences to be deeply immersed in their content. Through an explorative, qualitative content analysis (and parts of narrative analysis) aspects of immersion were explored in various 360-degree videos. Our results give an overview of multiple immersive factors in 360-degree storytelling and the interplay of narrative and technical aspects of immersion. Technical immersion manifests through cues to direct the viewer’s attention and cues to acknowledge the viewer as a part of the virtual environment. Narrative immersion, on the other hand, is influenced by the setting, as well as by the interplay of story, characters, and viewer integration. Our findings also indicate that narrative and technical aspects support each other to strengthen immersion.
Standards in Virtual Worlds Virtual Travel Use Case Metaverse1 Project
Authors: Cabello José Manuel , Franco José María , Collado Antonio , Janer Jordi , Cruz-Lara Samuel , Oyarzun David , Armisen Albert , Geraerts Roland
Published: August 2018

Nowadays, tourism has become a very important industry in the international economy. Information and communication technologies are in constant development; they progress worldwide and across sectors. Their applications in tourism and tourist resources is rapidly increasing, reaching new, innovative and sometimes amazing results in terms of effectiveness, productivity, quality, and customer satisfaction. Exploring the interaction between technologies and tourism is difficult and challenging. Specifically, using virtual world technologies as a new means of information for potential tourists is a big challenge where the actual methods, goals and needs still need to be exactly identified.This paper aims at analyzing why and how virtual worlds can become an important platform for tourism-oriented areas to promote a destination in general, and their local heritage and tourist added-value services in particular. The document will also introduce the design of the first prototypes and the validation results of the four specific technologies tested at the Virtual Travel Use Case (Soundscape generation, Multilinguality, Video streaming and Path and Camera Planning). Finally, the contribution to the MPEG-V standard will also be detailed in the paper.
The Demographic Distribution and Social Experience of Chinese MMO Players
Authors: Xiong Li
Published: August 2018

Nuanced knowledge of who plays and how is necessary for a meaningful understanding of behaviors in the virtual world (e.g. Williams et al., 2008). Despite increasing use of Massively Multiplayer Online games (MMO) in China, systematic investigation of the demographic distribution, play patterns and social experience of Chinese players is limited. Based on a large web survey of players of a large Chinese MMO (N = 18,819), this study examines the demographic distribution of Chinese MMO players and its influence on their play patterns and social experience. The results suggest that compared to male players, Chinese females engage in more text chat, are more likely to play with romantic partners and friends, perceive higher salience of social capital, but have a lower sense of community. Older players engage in less chat, adventure and competition activities, but have a stronger sense of community than younger players. Controlling for age and gender, Chinese players’ sense of community is positively predicted by their participation in guild activities and in-game chat. Implications of the findings are discussed with a focus on the potential cultural influence on virtual behaviors. (Aiming for the Asian Perspective issue)
Do As We Do, Not As You Think: The Effect of Group Influence on Individual Choices in a Virtual Environment
Authors: Kraemer Phil
Published: August 2018

Second Life (SL) is a virtual world application that enables users to create virtual representations of themselves and interact with other users. SL is increasingly being used to study important psychological questions. The current project sought to replicate within SL Asch’s (1951) classic finding of group influence, in which participants often respond in accordance with choices expressed by other members of a group, regardless of the accuracy of those choices. Participants were given a series of perceptual judgment trials, in which they chose one of three stimulus alternatives that matched the length of a target stimulus. Participants were tested either alone or with three other confederate avatars whose choices were predetermined by the experimenter. On two of the trials, confederate avatars unanimously chose incorrectly before the actual participant made their choice. Results showed that on these trials participants were significantly more likely to choose in accord with the confederate’s choices, relative to participants tested as single avatars. The results generally support earlier research on group influence and extend these findings to a virtual world environment.
Museum Discovery Institute: Girls Designing in Cyberspace
Authors: Kolodziej Suzanne , Corbit Margaret , Wofford Jennifer
Published: August 2018

In 2007, Cornell University piloted the Museum Discovery Institute (MDI), adding a new dimension to its commitment to educational outreach. The pilot program was aligned with the Girl Scouts’ National GirLink Initiative and its Museum Discovery badge requirements, in response to the organization’s initiative focused on girls and technology. Students visited bricks and mortar museums on Cornell University’s campus and designed and created their own 3D virtual exhibits in response to their learning experience during the museum visits. In this case study, we will describe and contextualize the framework of the educational experiences integrated into the Museum Discovery Institute as a reference resource for museum education professionals and classroom educators.
The Iron Law
Authors: Bainbridge William Sims
Published: August 2018

Star Wars: The Old Republic and Fallen Earth are two of the many recent online gameworlds that depict disintegrating and conflict-ridden societies, in which the very legitimacy of the law is in doubt. Thus they become vehicles for critique of real modern society, and intentionally or unintentionally reflect social-scientific theories of social disorganization, institutional functionality, and the origins of law. This essay examines these examples in terms of the Iron Law of Oligarchy proposed a century ago by Robert Michels, and related classical theories that either contradict or extend it.
Possible Futures
Authors: Sivan Yesha Y.
Published: August 2018

Our journal, JVWR, is celebrating this year its 8th year anniversary. This issue (our customary beginning of the year assembled issue) includes again the top of the crop of papers in our field. We would like to thank our Issue Editors Dr. Stephanie Blackmon from the University of Oklahoma (OK, USA), and Dr. Patricia Anderson from Carolina University (NC, USA) who took upon themselves to bring to our readers this Assembled 2015 issue.Much has changed since 2008 when the JVWR was founded by Jeremiah Spence. The virtual is becoming the real and the real is becoming the virtual. It seems that the term “virtual worlds” as a key term for an academic domain, does not make sense anymore.We look forward to jointly define the future (our next seven years) of this publication, and in doing so -- assist in the design of both real and virtual worlds.
The eSports Trojan Horse: Twitch and Streaming Futures
Authors: Burroughs Benjamin , Rama Paul
Published: August 2018

This paper argues that one potential future in gaming and virtual reality can be found in streaming media and technology. The streaming space of Twitch.tv is both “real” and “virtual”, blurring the boundaries between the game space, social networks, and face-to-face communication. Streaming ruptures a hard distinction between the real and virtual worlds. Scholars of virtual spaces need to take seriously streaming media as a site of research, and the affordances of streaming as networked, mobile, and curated. Twitch represents a space for unpacking the social and commercial realizations of an emergent streaming culture. Virtual world research needs to continue to push the boundaries of research into games and gaming culture. We argue that an important part of that future involves the liminal space of streaming and eSports between the real and the virtual.
Toward the Futures of Real AND Virtual Worlds
Authors: Sivan Yesha Y.
Published: August 2018

An overview of the special "Futures" issue and its papers, and reflection on how this field has changed from 2008 to 2015 along the four platforms of 3D3C (3D, Community, Commerce and Creation).
A Brief History of Virtual Economy
Authors: Nazir Mohamed , Lui Carrie Siu Man
Published: August 2018

The virtual world economy is a multibillion-dollar industry. There is significant evidence for the growth of virtual economies within a variety of virtual worlds. There is an increasing demand from users to buy, sell, and invest in virtual items and services, including virtual properties. However, there is also evidence suggesting that many companies struggle to succeed in the virtual economy platform. In order to facilitate and drive success in virtual business strategies, it is necessary to have a framework for classifying elements of virtual economies. This paper proposes a classification framework of virtual economy elements based upon the characteristics of products and services, the transaction and marketplace, as well as the currency and exchange systems present in these economic environments. In addition, this research highlights the opportunities and challenges presented to both users and companies within the virtual economy platform.
YouTubing Difference: Performing Identity in Video Communities
Authors: Anarbaeva Samara M
Published: August 2018

This study examines women’s performance of gender, ethnicity, and race in a “How-to & DIY” YouTube networks. Through textual and visual analysis, I examine a specific community of ordinary women who participate in the “How-to & DIY” category on YouTube. I look at four women’s YouTube channels, profiles, videos, and comments from their subscribers in order to reveal a deeper sense of what meaning users derive through creating videos on YouTube. I ask the following question: How do women in the YouTube Beauty community perform their identity and difference in their videos? After analyzing the videos and the dialogues, two themes have emerged: a sense of belonging and connectedness, and identity performance at the interface. Underrepresented women go to YouTube to relate to others who are like them, which gives them a sense of belonging and connects them to millions of others who are craving the same connection. Through video blogs, these women perform their gender, race, and identity.
Exploring Intrinsic Gender Identity Using Second Life
Authors: Mitra Barbara Maria , Golz Paul
Published: August 2018

Virtual worlds (VWs) provide an environment to understand and explore notions of gender and identity, particularly given the ability for users to experiment with gender in online worlds. Our study analyses gender identity using the virtual space of Second Life (SL) to explore experiences and responses to gender in an avatar. We introduced 46 novice users to the VW of SL in order to see if real life gender influenced their choices of avatar. Participants selected the gender of their original avatar and once they were used to SL, they were then asked to change the gender of that avatar. We used mixed methods research consisting of paper based questionnaires (n=34) and focus groups (n=46) conducted in SL. Nearly all participants chose an initial avatar that reflected their real-life gender with females (n=22) reporting higher levels of identification with this initial avatar. Females were significantly more concerned with the gender-specific appearance of their initial avatar. On swapping gender, females reported higher levels of discomfort and many changed back before 7 minutes. Males (n=24) did not report significant discomfort with their changed-gender avatar and did not revert back to their original avatar as quickly. Our findings suggest that female participants in this study tended to reinforce gender binaries through such things as clothing, hairstyles and behaviors of their avatars. Male participants were less likely to experience discomfort through changing the gender of their avatar (with the males noting they still perceived an avatar with a female appearance as male).
Factors associated with retention of community health workers in maternal, newborn and child health programme in Simiyu Region, Tanzania
Authors: Ngilangwa David P. , Mgomella George S.
Published: August 2018

Background: Attrition of community health workers (CHWs) continues to threaten the full realisation and sustainability of community-based health programmes globally. Aim: This study aimed to understand factors associated with CHWs’ recruitment and their retention. Setting: This study was conducted in five districts of the Simiyu Region, namely, Bariadi, Busega, Itilima, Maswa and Meatu in north-western Tanzania. Methods: In this cross-sectional study design, 341 CHWs who were working with the maternal health programme were randomly selected. Semi-structured questionnaires were administered to all participants. Data were descriptively and inferentially analysed using SPSS version 20. Results: Majority (58.0%) of CHWs were below 35 years. Over half (53.1%) had completed primary education only. Motivation factors for being CHW were aspiration to serve the community and desire for further training to become a qualified medical practitioner. Community recognition and financial incentives were among the key retention reasons for the CHWs. Being married (odds ratio [OR] 5.9, 95% confidence interval [CI] 1.7–20.1) having prior volunteer experience (OR 10.5 95% CI 12.7–40.5) and prior employment OR 21.8 (CI 12.2–38.9) were positively associated with retention of CHWs, while being a female was negatively associated with retention OR 0.4 (CI 0.2–0.8). Conclusions: Both financial and non-financial incentives were critical in contributing to the retention of CHWs. Thus, health programmes should carefully select CHWs by understanding their motives beforehand, and provide them with incentives.
Panorama atmosférico, escena tipificada, écfrasis simbólica. La función de las imagenes literarias en "Jürg Jenatsch" (1876) de C. F. Meyer
Authors: Ullrich Heiko
Published: August 2018

Se encuentran tres tipos principales de imágenes literarias en Jürg Jenatsch de C. F. Me­yer: la descripción del paisaje, los retratos de carácteres en escenas de género y la écfrasis de cuadros. Estos paisajes descriptivos son relacionados fijamente con la trama de la novela si la descripción lírica de la naturaleza refleja un cierto ambiente, las escenas de género exageran los rasgos característicos y los cuadros contribuyen al simbolismo de las constelaciones de carácteres por medio de la señalización de sujetos conocidos de la historia, la religión y las artes. Esta conexión entre la trama dinámica y las descripciones estáticas da variación al programa del realismo burgués aparece por no acentuar un molde de caracteres a través de su entorno físico y material, pero el hecho es que la trama depende de convenciones estéticas.
¿Un profeta de Alemania? Walter Benjamin y Siegfried Kracauer: acerca de Stefan George
Authors: Belforte María
Published: August 2018

El presente artículo se propone recuperar las lecturas de Walter Benjamin y Siegfried Kracauer de la obra georgeana. El análisis recorre las imágenes del profeta, el reformador y el juglar benjaminianas y las implicancias del Jugendstil presentes en la poesía de George. A partir de los estudios benjaminianos y las lecturas de Kracauer se interpreta la obra de Stefan George en dos etapas en las que se distinguen diferentes consecuencias políticas: en primer lugar, un intento de conjuración de la naturaleza mediante el artificio estético y un segundo momento, en el que tal ademán se dirige más concretamente al bloqueo de la voluntad utópica.
Espacios e identidades transitorias en las narraciones sobre el exilio. "Transit" de Anna Seghers y "Zwischenstationen" de Vladimir Vertlib
Authors: Giménez Calpe Ana
Published: August 2018

El presente artículo aborda la experiencia del exilio retratada en las novelas Transit de Anna Seghers y Zwischenstationen de Vladimir Vertlib a partir de la noción de lo transitorio. Para ello, me centraré no solo en la caracterización de los espacios del exilio como supuestos espacios de tránsito, sino también en el carácter cambiante de la identidad de los protagonistas, que consiguen acercarse, transitar, a las nuevas culturas de los países de acogida. Analizar las experiencias interculturales retratadas en las novelas nos permitirá nuevas lecturas de Transit, una obra ampliamente estudiada, así como constatar cómo la literatura del exilio clásico alemán anticipa ya algunos aspectos de novelas contemporáneas como Zwischenstationen.
Training Adequacy and Pedagogic Practices of Teachers in Reception Facilities for Refugee Education in Greece during the Economic Crisis: A Case Study
Authors: Asimaki Anna , Lagiou Archontoula , Koustourakis Gerasimos S , Sakkoulis Dimitris
Published: August 2018

This research paper, which uses Basil Bernstein’s theoretical framework, aims to search the training adequacy of the teachers who work in Reception Facilities for Refugee Education (RFRE) and to examine the pedagogic practices that they use at the micro-level of the school classroom. Teachers who worked in a RFRE in Greece participated in this research, which was conducted with the use of the semi-structured interview research tool. The findings showed the following: a) the insufficient training that the RFRE teachers had received from the official national bodies; the teachers’ effort to acquire the appropriate knowledge on their own initiative, in order to be able to teach refugee students; the teachers’ expressed need for training in matters of intercultural education, b) the pedagogic practices teachers used at the RFRE is linked to the implementation of an invisible form of pedagogy with a clear student-centered focus.
Efecto de la fertilización sobre el pasto Brachíaria híbrido CV CIAT BR02/1794 como medida de mitigación ante el cambio climático
Authors: Mejia-Castillo Harin Joel , Nájera Aparicio Kenny , Rubi Rober Danilo , Ramirez Carmen Nataly
Published: August 2018

Se evaluó el efecto de distintos niveles de fertilización (0, 50, 100 y 150 KgHa-1) sobre el rendimiento y composición nutricional en el pasto cobra (Brachíaria hibrido cv CIAT BR02/1794). Se evaluaron cuatro tratamientos con cuatro repeticiones, utilizando un diseño experimental en bloques completamente al azar. Las variables evaluadas fueron Rendimiento KgHa-1, Materia Seca, Proteína Cruda y Fibra. Se encontró que las variables respondieron favorablemente a la dosis de 100 KgHa-1 dando los siguientes resultados, para Rendimiento KgHa-1: 5,170.46 a los 30 días, Proteína cruda: 14.43% a los 30 días, FDA: 31.37% a los 30 días. Con los datos obtenidos en el estudio, se muestra que la fertilización nitrogenada tiene un efecto sobre el rendimiento y composición nutricional sobre el pasto Brachíaria híbrido cv CIAT BR02/1794, y el nivel de fertilización con la más alta relación beneficio/costo (1.40 Lps) fue el de 100 KgHa-1 .
Indicadores del impacto del cambio climático en la agricultura familiar andina colombiana
Authors: Nuñez Rodriguez Jose Jesus , Carvajal Rodríguez Julio César , Carrero Carreño Darcy Margarita , Mendoza-Ferreira Omaira
Published: August 2018

Los modelos de evaluación de los impactos del cambio climático utilizados en la agricultura colombiana se han enfocado en cultivos tecnificados, sembrados en grandes superficies, obviando que el 67% de la producción nacional de alimentos provienen de pequeñas extensiones de policultivos cultivados, en su mayor parte, en suelos de ladera de la cordillera andina, por 3,5 millones de agricultores y que aportan el 57% del empleo rural. El presente artículo se deriva de un análisis de la metodología empleada por los autores en el proyecto de investigación denominado “Impactos económicos, ambientales y sociales del cambio climático en el sector agropecuario del Municipio Bochalema, Departamento Norte de Santander, Colombia, financiado por la Universidad de Santander (UDES) y que abarca el período comprendido entre enero de 2017 y mayo de 2018. Después de analizar diferentes modelos de evaluación de impactos ambientales se seleccionó el modelo de Presión, Estado, Respuesta (PER) de la OCDE, previa adaptación a las características específicas de pequeñas unidades de producción agrícola de subsistencia. Se evidenció la multidimensionalidad y complejidad de los factores relacionados con el clima, la producción, los recursos, las tecnologías, las familias y las políticas públicas, que obligan a la construcción de indicadores contextualizados a la agricultura familiar andina.
Productividad potencial del SAF cacao asociado con árboles forestales
Authors: Sol-Sánchez Ángel , López-Juárez Sergio Alexander , Córdova-Ávalos Víctor , Gallardo-López Felipe
Published: August 2018

El objetivo de la investigación fue estimar el ingreso económico en un sistema cacaotal a partir de la sustitución de árboles de sombra muertos por árboles de pimienta y pronosticar el comportamiento del agroecosistema cacaotal al enriquecimiento con especies de alto valor comercial. Se realizó la investigación en los predios El Cometa y La Ceiba ubicados en el municipio de Comalcalco, Tabasco. En el sitio El Cometa, se registró la cantidad de árboles de pimienta, en cada una de ellas se midieron el diámetro a la altura del pecho, altura total, fuste limpio y se registró la cantidad de producción por árbol. Además, se registró la última producción de la cosecha obtenida para el cacao. En el segundo sitio, La Ceiba, se registró la cantidad de árboles forestales asociadas con el sistema agroforestal cacao. Para cada árbol se midió el DAP, altura total y fuste limpio. Con esto se obtuvo el área basal por individuo, para luego calcular el volumen comercial (vc) total de cada especie. Obtenido el vc (m3r) se obtuvo el precio de cada especie para ser colocado en el mercado. Cedrela odorata (L.) Gaertn, Swietenia macrophylla King y Ceiba pentandra (L.) Gaertn., estas fueron las especies que registran un mejor valor en el mercado de la madera nacional e internacional.
Instability in Reverse Total Shoulder Arthroplasty
Authors: Chae Jonathan , Siljander Matthew , Wiater J. Michael
Published: August 2018

Recently, indications for reverse total shoulder arthroplasty have expanded to include glenohumeral arthritis, rotator cuff arthropathy, irreparable rotator cuff tears, complex proximal humerus fractures, sequelae of trauma, and failed shoulder prostheses. Dislocation is a common complication, with rates ranging from 1.5% to 31%. The literature pertaining to management of instability in reverse total shoulder arthroplasty is scanty. Assessment of the patient and biomechanical and surgical factors is critical in determining the best course of treatment. Future studies involving patient selection, prosthetic design, surgical technique, and biomechanics may help reduce the rate of instability.
The Impact of Orthodontic Appliance on Body Weight Changes, Dietary Habits, and Self-Perceived Discomfort in Early Stages of Orthodontic Treatment
Authors: Ajwa Nancy , Makhdoum Lamya , Alkhateeb Hadeel , Alsaadoun Alanoud , Alqutub Samiah , Alkhumayes Hajer
Published: August 2018

AIMS: To assess and compare the changes in body weight, dietary habits, and pain perception of patient’s undergoing orthodontic treatment at the initial stage.MATERIAL & METHODS: This was an observational prospective cohort study to assess patient’s changes in body weight, dietary habits, and pain perception undergoing orthodontic treatment at the initial stage. Thirty patients who received orthodontic treatment “for the first time” and those who will get comprehensive orthodontic treatment within the age group of 18-30 years old including both genders were included in the study. The weight as well as dietary habits of patients were measured at the initial visit, “prior reserving of any the orthodontic treatment” as (T0). Re-evaluation of patient’s weight, dietary habits, and pain perception were re-assessed on the next visit” after fixed orthodontic appliance bonding” as (T1) one month later. The pain, discomfort, and dietary habits changes were evaluated using a validated questionnaire.RESULTS: The mean (SD) patient weight at first and second visit of orthodontic treatment was 67.43 (24.42) and 64.98 (22.7) kg respectively. The difference in the patient weight between first and second visit was statistically significant. Patients with discomfort and patients who used medication to relieve pain were reported to have more weight loss.CONCLUSIONS: This study confirms the initial loss of weight, pain and discomfort among patients who undergo orthodontic treatments. The findings of this study are of importance among the orthodontic centres and practitioners highlighting the importance of their guidance in structured diet planning and advice after treatment.
Influence of the Psychological Capital and Perceived Organizational Support on Subjective Career Success: The Mediating Role of Women's Career Adaptability in the Saudi Context
Authors: Ibrahim Mona Mohamed Sayed , Amari Amina Ahmed
Published: August 2018

This paper is the first to explore predictors’ keys of career adaptability and subjective career success in the Saudi context. Many employees, especially women, are facing several challenges in their work, and career adaptability is a way to overcome these difficulties to reach the career success. This research investigated the mediating role of career adaptability (CA) in the relation between both psychological capital (PsCap) and perceived organizational support (POS), as predictors of CA, and subjective career success (SCS). To test our hypotheses, we collected survey data from academic staff in Saudi universities in Riyadh. The results revealed a significant relation between both (PsyCap) and POS on CA. This relation also influenced the SCS through a partial mediation of CA.
Examination of selected properties of BNi-1a and BNi-2 coatings by DSI method
Authors: Kondej Adam , Babul Tomasz
Published: August 2018

This paper describes examination of selected mechanical properties of the Ni-Cr-B-Si coatings using the DSI method (Depth Sensing Indentation). The research was carried out on coatings obtained in a vacuum furnace-melting process of two alloys: BNi-1a and BNi-2. The alloys in paste form had a different content of Ni, Cr and Fe. Change in the content of these elements affects the size and density of the distribution of chromium borides. In the BNi-1a coating, the precipitations are fine-grained and densely distributed in the nickel matrix. While, in the BNi-2 coating they are larger and occur in dendritic agglomerations, on the surface they are in the form of plaques. The DSI tests showed that the BNi-1a coating has a higher hardness (by 22.4–25.0%), stiffness (by 39.4%) and creep resistance (by 7.9%) than the BNi-2 coating.