bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Housing Allowance Benefit Levels on Recipient Duration: Evidence from the Swedish 1997 Reform
Authors: Jie Chen
Published: July 2017

How the duration of housing allowance spells varies with the generosity of the housing allowance system carries important policy implications. In 1997, the Swedish housing allowance system implemented a drastic reform which substantially affected claimants who were couples with children in terms of their financial incentives to utilise housing allowance benefits. However, at the same time, the 1997 reform largely left single-parent claimants unaffected. Exploiting the quasi-experimental feature of this reform, this paper analyses the impacts of benefit shrinkage on couple-with-children recipients' exit hazards using the DD (difference-in-difference) estimation strategy. Careful attention is given to measuring interaction effects appropriately in non-linear models. The findings in this paper suggest that the 1997 reform led to a sharp increase in the leaving speed of the recipients in the `couples with children' category.
Policy Implications of Excess Commuting: Examining the Impacts of Changes in US Metropolitan Spatial Structure
Authors: Jiawen Yang
Published: July 2017

This article examines how changes in US metropolitan spatial structure lead to an increase in measurable excess commuting and a decrease in measurable transport—land use connections. Using Boston and Atlanta as two comparative regions, this research computes excess commuting with three-decade census data and then examines excess commuting in relation to the changes in metropolitan spatial structure. Empirical results suggest that the transport—land use connection appears weaker over the decades as the dispersion of jobs changes the dynamics of commuting and the selection of residential location follows patterns of average job location rather than that of the closest available job location. This decreasing transport—land use connection points to a spatial structure effect apart from individual preferences. It also suggests an alternative view of excess commuting for metropolitan transport policy-making.
Women, Mission, and the Early Franciscan Movement
Authors: Schroeder Roger
Published: July 2017

In an effort to help fill the lacuna regarding the role of women in mission history, this article focuses on women of mission within the context of the “evangelical awakening” and the early Franciscan movement in the Late Middle Ages. Clare of Assisi provided leadership and vision in founding the “Poor Clares.” Mary of Oignies is an outstanding figure of the Beguines—a new model of mission for women in Europe. Elizabeth of Hungary came out of the popular penitential movement as a precursor of the development of the Third Order. The article concludes by exploring the missiological implications and further questions for us today.
Urban Realities Amidst Social Complexities in Latin American Cities
Authors: Armet Stephen
Published: July 2017

The incredible growth of Latin American cities has resulted in social complexities that defy commonly held assumptions concerning urban culture. These stereotypes, if taken at face value, impede the development of an effective missiological and urban strategy. A closer look at marginality reveals adaptive and generative patterns of response among the poor that are conducive to the missiological task. Dispelling the myths of urban marginality provides insights that are incorporated in a missiological response to the urban realities facing the evangelical church in Latin America.
Reaching “Resistant” People through Intentional Narrative
Authors: Steffen Tom A.
Published: July 2017

Cross-cultural workers have ministered diligently for years to reach those living in the so-called “resistant blocs,” yet with little evidence of successful expansion of the kingdom of God. This paper will explore an often-overlooked factor that may contribute to this dismal track record—the lack of the intentional use of narrative in ministry. It will consider the need to expand training to incorporate narrative, ask why the various disciplines place such high emphasis on narrative, identify what is lost when the narrative genre takes a backseat, and suggest practical ways to incorporate narrative in reaching “resistant” peoples.
Christian Conversion and Culture in Russia: A Clash of Missionary Expectations and Cultural Pressures
Authors: Glanzer Perry L.
Published: July 2017

This article describes how individual Russians and Ukrainians influenced by two Western evangelical mission organizations understood their conversions. Through qualitative analysis, it provides evidence that the conversion stories of the former Soviets did not follow the pattern of quick conversion expected by the Westerners. The article concludes by suggesting that the cultural expectations and pressures influencing conversion resulted in conversions being a long-term process. In particular, a general disdain of quick converts, the cultural influence of Eastern Orthodoxy, and the radical worldview shift required when converting from communism to Christianity combined to slow the conversion process.
The Statistical State of the Missionary Enterprise
Authors: Jaffarian Michael
Published: July 2017

Drawing from the World Christian Encyclopedia, second edition (2001), this article presents new factual and statistical information by answering seven questions basic to world mission. Many important new discoveries and surprises are highlighted. The global status of religion, Christianity, and evangelization is described, and changes between 1900 and 2000 are considered, as well as significant trends in the decade of the 1990s. The article ends by advocating stronger missionary attention to the least-evangelized world and by defending the place of numeracy and statistical research in mission.
The Quest for Images of Missionaries in a “Post-Missionary” Era
Authors: George Sherron Kay
Published: July 2017

The global church enters the new millennium with a radically changed face and missionary situation. One of the results of post-colonialism and the globalization of mission is the declaration of the “post-missionary” era. This means that the only way Western missionaries can continue to engage in cross-cultural mission in today's world is by discovering and incarnating new images. The Bible offers the suggestive images of penitent sinner, beggar, friend, neighbor, follower, disciple, participant-observer, listener, and learner, which might mark the continuing conversion of the missionary today. These images flow from the triune God's self-emptying, self-giving, other-receiving, and other-empowering mission.
Weaving the Words: The Book of Ruth as Missiologically Effective Communication
Authors: Thomas Nancy J.
Published: July 2017

This essay explores the missiological significance of the book of Ruth from two perspectives. First, it looks at the book as a missiologically communicative text. A hermeneutic that considers the interweavings of context, content, and form shows the book of Ruth to be a story about God written in a culturally appropriate way for a particular audience at a specific time in their history. The hermeneutic presented serves as a model both for exploring other texts and for communicating in culturally relevant ways. Second, this essay looks at the book of Ruth in the context of the whole Bible and demonstrates how it illuminates God's mission in the world by showing the extent of God's redemptive love, reaching to the “stranger” and then reaching out through the stranger to the nations.
Builsa Proverbs and the Gospel
Authors: Moon W. Jay
Published: July 2017

This article analyzes proverbs from the Builsa people in Ghana, West Africa, which open a window to understanding the worldview and traditional theology of the people. Other forms of oral literature are also briefly included in order to enlighten further the analysis of the proverbs. With this understanding, the mother tongue Scripture is then engaged with the culture in order to bring understanding into both. This process is helpful not only for missionaries, but also for national church leaders as the interaction of the gospel and culture opens up new understanding that helps to foster the emergence of an indigenous church.
God's Purpose for Creation as the Key to Understanding the Universality and Cultural Variety of Christian Ethics
Authors: Van Den Toren Benno
Published: July 2017

The question in what respect Christian ethics are universal and in what respect Christian ethics may legitimately vary from one cultural context to another is a question of great interest to our worldwide church living in many different contexts. The problem is generally resolved by distinguishing between universal ethical principles and their culturally varying application. In this article it is argued that the problem is more fruitfully addressed when we understand ethics teleologically, in relation to God's goal and purpose for God's creation. In this way we can understand the universality of this goal and have a tool to analyze and evaluate the culturally varying ways in which God's purposes may be respected and aimed for, as is illustrated with respect to the African practice of the exchange of the bride price.
Commands from Heaven: Matteo Ricci's Christianity in the Eyes of Míng Confucian Officials
Authors: Chan Chung-Yan Joyce
Published: July 2017

Much scholarship on Father Matteo Ricci has been focused on the Jesuit missiological approach of accommodation. This essay investigates how the Chinese scholar officials in the Ming Dynasty perceived Ricci's presentation of the Christianity. The first section of the article deals with the sociopolitical context of Ricci's work. The second section discusses Ricci's presentation of the Christian message. Finally, the third section—through the writings of two key Chinese converts, Xú Guangqi and Yáng Tíngyún—looks at why Christianity won over Buddhism and Daoism (Taoism) as the religion of choice for the Confucian scholars.
Liana-Seti Origin Myths Corrected and Answered by Biblical Myths
Authors: Mccollum Frank , Ifamut Endemina
Published: July 2017

In times past, Christian missions emphasized significant culture change as an essential missionary goal. Recent missiology has moved toward a respect for the culture of the target society. In contrast to this movement, religious emissaries to the Liana-Seti people of Indonesia have overtly repressed that culture so that it might be replaced with a form of officially approved Christian culture. This has resulted in a bifurcated culture and ineffective Christianity. In an effort to respect the indigenous culture while challenging it, the current authors experimented with a narrative form of communication that respectfully incorporated the origin mythology1 of the people.
Missiology in an African Context: Toward a New Language
Authors: Oborji Francis Anekwe
Published: July 2017

The present paper discusses the question of missiology in an African context and raises the following questions: What has been the prevailing missiology in Africa? What can Africans say about missiology in the new century? Have Africans something to contribute in missiology, or should they continue to be consumers of the mission theology and the version of Christianity developed overseas? Can African churches be fully participant in the evangelization of the continent and of the world? And finally, what kind of contribution can African theologians make in order to promote the inculturation of the Christian faith and of human promotion in the continent? In exploring these issues, the author has chosen to emphasize the importance of a new language for missiology in Africa1 and the need to correct the inaccuracies of the fifteenth and nineteenth centuries' foreign missionary accounts of the culture and people of the continent, which are still very much with us and are not about to go away. The paper underlines the irreplaceable role of African intellectuals and gifted theologians in the development of new cultural identity and language for missiology in the continent.
Now it is Your Turn: East Africans Go in Mission
Authors: Healey Joseph G.
Published: July 2017

This study presents a wide variety of data and examples on East African (Kenyan, Tanzanian, and Ugandan) Catholic missionaries going to other places in their own country, to other countries in Africa, and to other continents. The increasing number of African priests, Brothers, Sisters, and laypeople being sent throughout the world is striking and has important ramifications for the future shape of global Catholicism and global Christianity. The letters (including personal testimonies) from Kenyan missionaries around the world are a source of narrative missiology. Like the famous mission diaries of old, these letters portray both the personal struggles and the searching of the African missionaries themselves and the methods of their missionary evangelization.
The Dynamics and Dismantling of White Missionary Privilege
Authors: Lewis Bonnie Sue
Published: July 2017

Lest we become too smug that we have moved beyond the ethnocentric attitudes and sins that often marred the work of our missionary forbearers, we are challenged to look again at the policies and practices of the church toward indigenous churches and church leadership. Focusing on the work of the Presbyterian Church (USA) among Native Americans and Native Alaskans, this essay posits that the complex and paradoxical dynamics of white missionary privilege and its dismantling often owe more to the tenacity of Native leaders who even to this day wish to remain within the church, than to the efforts of the dominant church members.
The Changing Face of Christianity: Revisiting African Creativity
Authors: Komolafe Sunday Babajide
Published: July 2017

The explosion of Christianity in twentieth-century Africa is a radical development that is transforming the world's largest religion. This calls for a reorientation of the hegemonic view that sees Christianity as a product of imperialist expansion and Africans as passive recipients of the ecclesiastical construct of the enlightened Western mind. Instead, the vitality of Christianity on the continent represents a demonstration model of African creativity with its peculiar character, shape, and form. This paper examines the principal contributing factors of the massive growth of the church on the continent and sees African creativity as a vigorous attempt to contextualize Christianity to local aspirations.
Mizo “Sakhua” in Transition
Authors: Pachuau Lalsangkima
Published: July 2017

Mizo people, a small ethnic group spreading across the international boundary from India's northeast to Myanmar, has come to understand itself as nothing less than Christian. After fifty years of its introduction among the Mizos, the Gospel has transformed this community into a zealous missionary-minded Christian people. In this article, the author, who is a Mizo himself, examines if and how features of traditional primal religion of the Mizos continue in Mizo Christianity. After delineating the main characteristics, essential beliefs, and practices of the primal “animistic” religion of the Mizos, the article then analyzes how the new religion was received and conceptualized by the people to produce its distinctive Christian nature. Not discounting the transforming act of conversion, the author concludes that there are strong lines of continuity when the primal worldview and ethos came to be utilized as connecting links to the message of the new religion.
The Role of Ethnicity and Culture in Shaping Western Mission Agency Identity
Authors: Whiteman Darrell L.
Published: July 2017

How do we live with our social identity and not deny who we are culturally, while at the same time recognize that our spiritual identity must take precedence over any cultural or ethnic allegiance? This is the challenge that missionaries and mission organizations face today. The issue before us is to understand how we can celebrate cultural diversity as an expression of God's creation in the body of Christ, without that diversity degenerating into ethnic rivalries within our mission organizations and our churches. This article explores the issues of identity and ethnicity as they relate to mission and the church, and makes four recommendations for a way forward through the ethnicity maze.
A Peek in the Baggage of Brazil's Pioneer Missionaries
Authors: Arnold Frank L.
Published: July 2017

It cannot be denied that pioneer North American Presbyterian missionaries arrived in Brazil with some cultural baggage and that it spilled out into their ministry. But to what extent did their concepts of church and society leave a mark on Brazilian Presbyterianism as it is today? Brazilian church historians differ on the answer to that question. In this essay the author looks at the work of the pioneers for evidences of negative influence in the Brazilian church of the nineteenth century North American concepts of Manifest Destiny and the “Spiritual Church.” He finds evidence that the pioneers are not as blameworthy in these areas as some have charged.
The Changing Face of Mission: Implications for the Southern Shift in Christianity
Authors: Laing Mark
Published: July 2017

The southern shift in the center of gravity of Christianity has far greater implications than just numerical changes. It marks a profound change in the constitution of Christianity. With the change, world Christianity undergoes a translation from being a predominately Western culture construct to having a myriad of diverse cultural expressions. The implications of this shift are of central importance as the church in the 21st century increasingly faces the dual challenge of a non-Christian West and a non-Western Christianity, and the complex relationship between the two.
Navigating the Limitations of Western Approaches to the Intercultural Encounter: The Works of Walter Ong and Harry Triandis
Authors: Hurteau Robert
Published: July 2017

The article explores the work of two social scientists, Walter Ong and Harry Triandis. Ong has postulated stark differences in thinking processes and behavior between people who are of literate cultures and people who are of more orally based cultures. Triandis has described a continuum of cultural difference between collectivist and individualist orientations of social groups. The particular assumptions of the Western cultural tradition (which generally assume literacy and individualism as normative) are critiqued as these come into play in relation to transcultural mission among rural Aymara people in southern Peru.
They Were So Alive!: The Spectacle Self and Youth Group Short-Term Mission Trips
Authors: Linhart Terence D.
Published: July 2017

The proliferation of short-term mission trips among youth ministry groups has vaulted them to prominence, an event often anticipated by adolescents to be significantly life-changing. This article reports research that clarifies the impact that anticipation has on the students as they explored their identity in light of cross-cultural service and mission. Despite the opportunities for growth and the fresh perspectives gained on identity, the short-term trip and its designs were informed by the spectacle culture from which the students came.
Shalom Tourist: Loving Your Neighbor While Using Her
Authors: Adeney Miriam
Published: July 2017

Tourism is growing in many local economies. Short-term missions is part of this wave, as perceived by travel agents, hoteliers, transporters, health service providers, government bureaus, and vendors. Tourism ethics have been discussed in the secular literature for years. It behooves Christians to reflect on the ethics of tourism: How can we travel to the glory of God? What patterns will maximize shalom both for those who travel and for those who serve them? Economic, social, and spiritual costs and benefits are explored in the context of pilgrimage.
Pentecostalism and Mission
Authors: Klaus Byron D.
Published: July 2017

This essay suggests that Pentecostals are most clearly understood when seen through a lens of mission. Their history is really a vigorous participation in a story of eschatolotical significance supported by Holy Spirit empowerment. A survey of the 20th century by decade sees the emergence of Pentecostal mission thinking deeply impacted by Roland Allen in its earliest years and maturing to speak for itself and engage the missiological themes of the later 20th century. The success of Pentecostal growth worldwide signals the necessity of serious missiologial reflection on that success, realizing that Pentecostals from the majority world will have significant impact on global Christianity in the 21st century.
Christ, Church, and the Cosmos
Authors: Komolafe Sunday B. Babajide
Published: July 2017

Through 20 centuries since the Word became flesh and lived among us, the theological evolution of Christianity cannot be discussed without close reference to the activities of the church as a servant-steward of God's cosmic mission. This paper discusses mission as the hermeneutic for biblical interpretation since Ephesians presents a “cosmic Christology” with its main focus on Christ and about the Church as it fulfills the purposes of Christ. It concludes by provoking an “ecclesiology of responsibility.” That is, an ecclesiology that does not pay tribute to the letter as belonging only to ancient times, but one that recognizes it imposes an obligation relevant for being the church of Christ in the world today.
Fool's Gold
Authors: Hertig Paul
Published: July 2017

They've got a name for the winners of the world, I want a name when I lose They call Alabama the Crimson Tide, Call me deacon blues

The title of this study is deliberately ambiguous. “Fool's gold” is known to be false gold; gold for fools, gold that fools. However, with an emphasis on gold rather than on fool, “fool's gold” means gold from a fool, my intended meaning. I am deliberately ambiguous, however, because, for his readers, Paul's use of the word “fool” is just plain folly; they miss the point, and cannot get beyond the plain meaning. Furthermore, Paul himself was ambiguous in his self-portrayal as fool. In one breath he says “Let no one take me for a fool.” In another he states just the opposite: “we are fools for Christ” and “God's foolishness is wiser than human wisdom.” He also states, “you should become fools so that you may become wise (2 Cor 11:16, 17; 1 Cor 4:10; 1 Cor 1:25; 1 Cor 3:18). Paul reinforces his self-description of “fool” for Christ (4:9) with ancient Greek theater imagery. Most notable is: “spectacle” ( theatron); “be imitators” ( mimetai — the verbal form of the mime); and “fool” ( môros, or “moron”) — a bit part, low class actor in the mime. Through theater imagery, Paul weaves together theological, sociological, and political themes that lie at the heart of his missiological engagement with the world.

Paul's nuances of ‘fool’ reveal the secret of humility and suffering in the context of discipleship. His assertion, “imitate me” in the “ways of the Lord” (4:16.17), speaks to issues that divide the Corinthian community: imitate me, the low class fool, the team player, rather than the wise of the world that set themselves above others. Paul's use of ‘fool’ is examined in 1 Corinthians 4, satirically, ironically, historically, theologically, and missiologically. This opens up windows to the contemporary emerging church and its inverted nature as a contrast to traditional church structures and hierarchies.
Making and Keeping Anthropological Field Notes
Authors: Smalley William A.
Published: July 2017

The individual who is resident among the people of another culture, even though he is not a professional anthropologist, has marvelous opportunities for observation, for casual or intensive interviewing, and for other ways of gaining extensive information about the people around him and their way of life. He often has a very real advantage over many professional anthropologists in the possibility of such contacts over a period of many years. Only a small percentage, however, of missionaries and other such residents abroad make any kind of systematic record of what they learn. This article discusses briefly the advantages of record-keeping, and makes some practical suggestions.
Cultural Shock: Adjustment to New Cultural Environments
Authors: Oberg Kalervo
Published: July 2017

Culture shock tends to be an occupational disease of people who have been suddenly transplanted abroad. Like most ailments, it has its own symptoms, cause, and cure. Many missionaries have suffered from it. Some never recovered, and left their field. Some live in a constant state of such shock. Many recover beautifully. As will be clear from the implications of Dr. Oberg's article, the state of culture shock in which a Christian lives will have great bearing on his temperament and witness.
The Great Revival of 1907 in Korea: Its Cause and Effect
Authors: Cho Eunsik
Published: July 2017

The Great Revival of 1907 in Korea and the church growth of the 1970s have common aspects. In the early 1900s, the Korean people had experienced national misfortune and Japanese political interference. In the 1970s, the dictatorship of the military government was strongly oppressing people. Political and social unrest encouraged people to turn to God for answers.

Another common thread was the church leaders' neutral attitude toward the political authority. Those two events have “dehistorical” and “denational” aspects. Missionaries of the 1900s and pastors of the 1970s changed the direction of mission or ministry from national concerns to spiritual dimensions, and from being against injustice to obeying authority. As a result, the Korean church grew in numbers, but the Korean church minimized its social concerns and forgot its prophetic role in society.

One of the important lessons is that although people had a certain intention or plan, the Holy Spirit worked in different ways through those events.
Reading the Bible through Filipino Eyes
Authors: Bowe Barbara E.
Published: July 2017

This paper presents first a brief introductory reflection on the “stranger as guest”—the strengths and weaknesses of a foreigner's perspective on cultural difference. Part Two presents an analysis of reading the Bible in a Filipino context. Part Three examines the world of the Filipino reader with special attention to three primary characteristics shared by the biblical world and Filipino culture: namely, an emphasis on honor and shame, concern for indebtedness and reciprocity in social relations, and the sense of dyadic personality and corporate consciousness. Part Four employs these insights in some examples of reading the Pauline letters through the eyes of a Filipino. This “reading” demonstrates the richness of cross-cultural (i.e., non-Western) experience as a resource for interpreting biblical texts.
Missionary Biography: A Select Annotated Bibliography
Authors: Anderson Gerald H.
Published: July 2017

Where does one begin a study of missionary biography? Here are suggestions from the editor of the Biographical Dictionary of Christian Missions. He also points out the need for further research and writing in certain areas of biographical study. Readers can use this bibliography as a starting point to develop their own list for reading or teaching about the life and work of important figures in the history of missions.
Song of Ascents: Autobiographical Reflection and the Development of the Mission Theory of E. Stanley Jones
Authors: Bundy David
Published: July 2017

E. Stanley Jones (1884–1973) is one of the important mission theorists of the twentieth century. Because most of his writings are in some sense autobiographical, he has not been treated in studies of mission theory. This essay describes and analyzes the development of Jones' mission theory. It is argued that part of the power of the theory is that it was framed in the context of autobiographical reflection. Through this reflection Jones sought to bring his understanding of the kingdom of God into congruence with his experiences of life and mission, in India as well as the United States of America.
Teacher of Preachers: Sue McBeth and Her Mission to the Nez Perce
Authors: Hoyle Lydia Huffman
Published: July 2017

Sue McBeth was one of many single Protestant women missionaries who served among the Native Americans in the nineteenth century. Like the majority, she worked as a teacher. Her teaching, however, was not confined to children. Working among the Nez Perce, McBeth trained a generation of ministers who led the tribal Presbyterian churches. Although physically weak, McBeth was tenacious of spirit. She knew what she was called to do and would not allow governmental or denominational entities to deter her. Through her life, one can see the empowering nature of the missionary calling.
Nitrile-EPDM Polymer Blends Fundamental Considerations for Development of Key Properties
Authors: Mitchell Julian M.
Published: July 2017

The method of polymer-carbon black addition to the Banbury has a very definite effect on the development of the NBR-EPDM blend features. The conventional mix provides excellent dispersion, the best balance of properties and the best economics.

The cure system has an important influence on the blend properties. Sulfur-accelerator cures designed for co-vulcanization of NBR-EPDM develop uniform physical properties through the entire blend range. Peroxide cures also provide uniform physical properties, better oil resistance and better ozone resistance at low levels of EPDM.

The EPDM polymer composition has a dramatic effect on the blend properties. An EPDM polymer with equivalent viscosities and high unsaturation has good development of the essential blend properties. However, an EPDM polymer which is higher in viscosity and ethylene with normal unsaturation, the physical properties are constant through the entire blend range.
Fabricating With Liquid Silicone Rubber
Authors: Hays W. R. , Kehrer G. P. , Monroe C. M.
Published: July 2017

During the last several years, new systems have been developed for the production of silicone rubber parts. These systems offer major reductions in both capital and labor costs. This paper discusses these developments with an emphasis on material properties and potential benefits to the user.

The principal methods used to produce molded parts and supported extrusions from liquid silicone rubber are described. Advantages of these systems include quick cure, pumpability, ease of use and lack of solvents. Data documenting the good heat stability, flame retardance, and improved compression set characteristics of the liquid silicone rubbers are presented. In addition, case histories will illustrate the primary benefit of reduced cost per finished part derived from the fast cycle times, lower energy requirements and automation available from this new technology.
UHMW-PE Fiber as Reinforcing Materials in EPDM Rubber Vulcanized by E-Beam Radiation
Authors: Shaker Manal , Kamel Ihab , Abdel-Bary E. M.
Published: July 2017

Ethylene-propylene-diene terpolymer (EPDM) was reinforced with different concentrations of Ultra high molecular weight polyethylene chopped fiber (Spectra?m 1000). The reinforced samples were vulcanized using different doses of E-Beam radiation. It was found that E-Beam radiation improves the interfacial adhesion between UHMW-PE fiber and EPDM matrix which was detected by scanning electron microscopy (SEM). In addition the Young's modulus of the composites increases as irradiation dose increases. Increasing the concentration of the fibers up to 40 phr leads to an enhancement in mechanical properties and swelling resistance of obtained composites, especially in the absence of carbon black. In contrast, the tensile strength of EPDM loaded with carbon black decreased as fiber concentration increased even though the other mechanical properties were improved. Although the tensile strength decreased with increasing fiber concentrations, the absolute value of the tensile strength increased by at least three fold with the addition of carbon black.
Physical, Mechanical and Thermal Degradation Properties of Ethylene Vinyl Acetate and Hydrogenated Nitrile Rubber Blends
Authors: Thavamani P. , Khastgir D.
Published: July 2017

The physical properties, aging, oil, fuel, saline water resistance and abrasion resistance of miscible blends of ethylene vinyl acetate (EVA) copolymer and hydrogenated nitrile rubber (HNBR) are reported. The thermogravimetric analysis (TGA) and microscopic studies of the fracture surface have also been included in this study. At ambient temperatures the tensile and tear strength increase with EVA content in the blend, but above 50°C an opposite trend is observed due to softening of crystalline segments in EVA. Aging, oil, fuel and saline water resistance increase with HNBR content in the blend. The abrasion loss increases steeply with increasing proportions of EVA. Ridges perpendicular to the direction of abrasion are observed in the worn surface of the blends containing more than 30 parts of EVA and the ridge spacing increases with EVA content. The abraded surface of HNBR does not show any ridges except scores in the direction of abrasion. The mechanism of wear changes from fictional to abrasive wear for HNBR rich blends. The TGA studies reveal the improvement in thermal stability of EVA on blending it with HNBR. Scanning electron microscopic observations of the tensile fracture surface show a ductile type of failure for blends having up to 50 wt.% of EVA whereas for HNBR rich blends, the failure is more similar to a brittle type.
Effect of Selected Inorganic Fillers on the Processing Characteristics, Technological Properties and Flammability of Natural Rubber Vulcanizates
Authors: Mathew George , Thomas Sabu , Kuriakose Baby
Published: July 2017

A wide variety of elastomer based products are commonly used for applications such as tires, gloves, tarpaulins, rubber bands, conveyor belts, floor tiles, carpet underlays, etc. Since most of these products are for indoor applications, they must have good flame resistance for safe and adequate protection. The authors have analyzed the effect of a series of inexpensive inorganic fillers on processing characteristics, technological properties and flammability of natural rubber. The flame retarding performance attributed to these fillers is compared against those of two standard and accepted flame retardants zinc borate and alumina. The results of the study show that talc and mica powder retard flammability of natural rubber satisfactorily without adversely affecting other technological properties.
Study of Rheological Properties of ISOCURE® LF-305/904 G Binder System
Authors: Bakhtiyarov Sayavur I. , Overfelt Ruel A.
Published: July 2017

Viscous and thermal properties of a phenolic resin (Part I) and a polymeric isocyanate (Part II), and their blends were investigated by using rotational viscometry. The elastic properties of the blends were investigated by means of a jet thrust technique, using a straight tube. The theological and thermal properties of the blends were dependent on the blend composition. Although both materials are Newtonian liquids, their blends exhibit non-Newtonian liquid flow behavior and elasticity. A thermo-reaction has been observed and investigated after mixing the two parts.
Water-Borne Thermosets from Aniline-Based Telechelics
Authors: Viswanathan Trro , Feng Qiuwei , Toland Alan
Published: July 2017

Current trends in the polymer coatings arena focus on water-borne formulations due to the obvious economic and environmental advantages of these systems devoid of organic solvents. This, coupled with the recent findings of the efficacy of polyaniline in corrosion prevention of metals, has provided impetus in the synthesis of water-borne thermosets from aniline-based telechelics. The first part of the project demonstrates the feasibility of the synthesis of telechelics with differing sizes and the second part deals with its derivatization to water-borne systems. Thus, a series of aniline-based telechelics have been made by varying the ratio of the reactants, viz. phenylenediamine and aniline, the amount of oxidant (ammonium persulfate) as well as temperature. Combined with higher solubility and reactivity, curing of the functionally reactive amino-terminated oligomers have been accomplished using aqueous formaldehyde or water-dispersed epoxy resins. Spectroscopic studies have been carried out to characterize some of the prepolymers as well as cured materials.
Emulsion Polymerization of Vinyl Acetate and Styrene Monomers in Presence of Polymeric Surfactant
Authors: Ayoub Magdy M. H.
Published: July 2017

Polymeric surfactant was prepared from polyoxyethylene methylether (POE, 66 wt%) and styrene (St, 34 wt%) in the presence of benzoyl peroxide as initiator using a macroradical polymerization technique. Fourier Transform Infrared Spectroscopy (FTIR) and 1HNMR were used to confirm the formation of graft copolymer. The cloud point for the obtained graft copolymer was found to be 75°C. The stabilizing efficiency of this nonionic copolymer as surfactant was tested in the emulsion polymerization of vinyl acetate and styrene monomers in the presence of potassium persulfate (K2S2O8) as initiator. The rate of polymerization was found to be proportional to the 0.9th and 0.76th power of initiator concentrations, and to the 0.77th and 0.66th power of the surfactant concentrations for vinyl acetate and styrene monomers, respectively. The apparent activation energies were found to be 69.13 and 50.27 kJ/mol for emulsion polymerization of vinyl acetate and styrene, respectively.
Conversion of Tire Waste Using Subcritical and Supercritical Water Oxidation
Authors: Park Yoonkook , Reaves J. Todd , Curtis Christine W. , Roberts Christopher B.
Published: July 2017

The properties designed into tires that make them strong and chemically resistant also inhibit their ability to be recycled easily Conventional liquid solvents do not sufficiently dissolve waste tires and tire production material for convenient separation. Supercritical water oxidation (SCWO) may provide an alternative solution to this environmental problem. Partial SCWO can be used as a means to partially break down rubber (polymeric) waste materials into lower molecular weight components that could be recovered as a chemical feedstock. In this study, the feasibility of converting waste material from tire production into useful products is explored. Batch SCWO studies illustrate the ability to efficiently break down the waste tire production material into a range of lower molecular weight organics for possible reuse depending on reaction conditions. Furthermore, a semi-continuous process has been developed and preliminary results are presented. Destruction efficiencies of greater than 0.9 were obtained in all runs regardless of reactor type. The results show SCWO to be a promising remediation alternative to the waste tire problem.
Tracking Resistance of Flame Retardant Glass Reinforced PBT
Authors: Tjahjadi Mahari , Gallucci Robert R.
Published: July 2017

While polybutylene terephthalate (PBT) resins have excellent electrical properties, addition of standard brominated flame retardants (FR) is known to diminish electrical performance. However many electrical devices, such as switches and especially circuit breakers, require ignition resistance imparted by the bromine additives. A new mineral glass filled FR-PBT technology has been developed that retains the mechanical properties and easy flow of the existing FR-PBT thermoplastics while improving electrical properties to the level of performance seen in thermoset resins.

Products using the new additive technology have been developed that give UL-94 FR ratings of V-0 at 0.75 mm, 5VA at 2 mm and CTI values of over 600 volts. Devices made from this resin also show arc resistance of >180 sec (class 4). High amp arc ignition is >120 arcs. Thermal index with electrical properties is 130°C.
Techno-Economic Feasibility and Flowsheet Synthesis of Scrap Tire/Plastic Waste Liquefaction
Authors: Shelley Mark D. , El-Halwagi Mahmoud M.
Published: July 2017

A techno-economic feasibility study was undertaken to assess the viability of co-liquefying scrap tires and post-consumer plastic wastes into liquid transportation fuels. First, a generalized process flowsheet was synthesized. Next, material and energy balances as well as process simulations were developed. Finally, a profitability analysis was completed for all process scenarios investigated. Two different base case scenarios were considered: (1) the melting/depolymerization of waste plastics and the pyrolysis of scrap tires and (2) the pyrolysis of both waste plastics and scrap tires. For the techno-economic assessment, waste plastic and scrap tire feed rates of 200 and 100 tons per day respectively were assumed. Costs for individual pieces of equipment were either rigorously calculated or scaled down from literature sources. In addition to the two base case scenarios, two separate modules were also considered: (1) the melting/depolymerization and upgrading of waste plastics alone and (2) the pyrolysis and upgrading of scrap tires alone. The economies of scale for these two modules were also analyzed. The results for both base case scenarios indicate that a 15% rate of return on investment (ROI) can be achieved if a waste plastic tipping fee of $35-$45 per ton can be secured. Furthermore, the economic analysis of the two modules reveals that tire pyrolysis has an ROI of 18% while the ROI of plastic melting/depolymerization is much lower. This result is expected since the potential tips and revenues from scrap tires is greater than those from waste plastics. Due to economy of scale, the process economics for both modules is considerably improved as capacity is increased. Thus, these results affirm that the co-liquefaction of waste plastics and scrap tires as well as the liquefaction of scrap tires alone is both technically and economically feasible.
Rheological Behaviour of Unvulcanised Natural Rubber Compounded with Cryogenically Pulverised Polyurethane Foam Particles
Authors: Sombatsompop N.
Published: July 2017

Cryogenically flexible polyurethane (PU) foam particles at various concentrations were introduced as a new filler into the natural rubber compounds and the theological properties were studied using a Davenport Capillary Rheometer. The effect of mastication time and die temperature on theological properties and extrudate swell behaviour of the rubber compounds was also investigated. It was found that Theological properties and extrudate swell ratio changed considerably with addition of PU filler, mastication time and die temperature. With respect to Theological behaviour, it is recommended that 20-30 pph PU filler is the optimum concentration to be introduced into natural rubber compounds under the mastication time of 15 minutes for a given die temperature.
Dynamic Response of Impact Damaged Random Fiber Automotive Composites
Authors: Sadasivam B. , Cherng J. G. , Mallick P. K.
Published: July 2017

This study concentrates on the effects of low energy impact damage on the dynamic response of four random fiber reinforced composites that are commonly considered for automotive body and chassis applications. They include both thermoset and thermoplastic matrix composites. Impact damage is caused on composite plate specimens using a drop weight impact testing machine. Several different impact energy levels are considered and the severity of impact damage is macroscopically determined. The dynamic response of impact damaged composites is compared with that of unimpacted composites. Correlations are obtained between the input impact energy and changes in dynamic properties that include both natural frequencies as well as damping factor.
On the Effective Elastic Properties of Composites with Evolving Microcracking
Authors: Caiazzo A. A. , Costanzo F.
Published: July 2017

The goal of this paper is to discuss the practical implementation of a thermodynamically based procedure for the derivation of the effective response functions of composites with evolving microstructure. An example of implementation of said procedure for the case of a linear elastic periodic composite with one growing crack is presented. This example is intended to show how the use of this procedure differs from a global-local approach and how it can be generalized to study complex microstructures characterized by many cracks.
Finite Element Analysis of Low-Velocity Impact Damage in Composite Laminates
Authors: Pradhan B. , Kumar S.
Published: July 2017

This paper investigates the low-velocity impact behaviour and impact-induced damages in graphite/epoxy composite laminates. A three-dimensional finite element and transient dynamic analysis is performed to calculate the time-varying displacements, forces, strains and stresses throughout the laminate resulting from transverse impact. A layered version of an eight-noded isoparametric brick element with incompatible modes is used to model the laminate. Transient dynamic equilibrium equation is integrated step-by-step with respect to time using Newmark direct time integration method. Modified Hertzian contact law is used to model the local contact behaviour. Appropriate three-dimensional failure criteria are used for predicting the occurrence of matrix cracking and the extent of delamination after impact.
Quantifying Uncertainties in the Thermo-Mechanical Properties of Particulate Reinforced Composites
Authors: Mital Subodh K. , Murthy Pappu L. N.
Published: July 2017

Recently, there has been a growing interest in the use of particulate reinforced composites in a wide variety of applications. Particle reinforced composites are candidate materials for structures where shock or impact loading is expected. The ICAN (Integrated Composites Analyzer) computer code developed at NASA-Glenn Research Center has been modified to include micromechanics equations for particle reinforced composites. In this work, the simplified micromechanics of particulate reinforced composites and a fast probability integration (FPI) technique have been used to obtain the probabilistic composite behavior of a Al/Si Cp (silicon carbide particles in aluminum matrix) composite. The probability density functions for composite moduli, thermal expansion coefficient and thermal conductivities along with their sensitivity factors are computed. The effect of different assumed distributions in constituent properties and the effect of reducing scatter in input random variable on a select composite property-namely the thermal expansion coefficient are also evaluated. The variations in the constituent properties that directly effect these composite properties are accounted for by assumed probabilistic distributions. The results show that the present technique provides valuable information about the scatter in composite properties and sensitivity factors, which are useful to test or design engineers.
An Experimental Method to Continuously Measure Permeability of Fiber Preforms as a Function of Fiber Volume Fraction
Authors: Stadtfeld H. C. , Erninger M. , Bickerton S. , Advani S. G.
Published: July 2017

Liquid composite molding processes have the potential to produce complex shaped parts utilizing tailored fiber reinforcements and inserts. Existing simulation tools have the capability to predict the flow front advancement as the resin impregnates the fiber preform to saturate it, thus minimizing cost intensive trial and error approaches to successful mold filling. An important input to such simulations is the permeability of fiber preforms, which describes its resistance to flow. Permeability is a function of the fiber architecture and fiber volume fraction. Traditional experimental methods to measure permeability allow one to obtain a single value at a prefixed fiber volume fraction; hence, if one wants to obtain permeability over a wide range of fiber volume fractions, a multitude of experiments are necessary. This paper introduces a novel approach to determine permeability over a wide range of fiber volume fractions in one continuous experiment using the same preform. Repeatable results for woven glass fabrics over a range of fiber volume fraction are presented.