bluuebunny/crossref_metadata_2025 huggingface dataset:
Bringing Mohamed to the Mountain: Situated Professional Development in a Ubiquitous Computing Classroom
Authors: Swan Karen , Kratcoski Annette , Mazzer Pat , Schenker Jason
Published: October 2005

This article describes an ongoing situated professional development program in which teachers bring their intact classes for an extended stay in a ubiquitous computing environment equipped with a variety of state-of-the-art computing devices. The experience is unique in that it not only situates teacher learning about technology integration in their regular practice, but also gives them the opportunity to explore the full possibilities afforded by a variety of technologies and 1:1 computing opportunities. The program provides an important alternative model for professional development that has been highly successful, not only in increasing teachers' knowledge and confidence in technology integration but also in changing the ways in which teachers think about and use a variety of technologies in their classrooms. Findings also suggest that ubiquitous computing environments afford unique teaching and learning opportunities upon which ordinary classroom teachers can capitalize to a greater or lesser degree.
“At This Point Now”: Older Workers' Reflections on Their Current Employment Experiences
Authors: Noonan Anne E.
Published: October 2005

Despite the frequently referenced graying of the U.S. workforce, we know relatively little about the work-related concerns and experiences of older workers—those aged 55+. This qualitative study addresses that gap by examining the current employment situations of a purposive sample of 37 older workers. Thematic content analysis revealed a vast diversity in the concerns and experiences of contemporary older workers, with participants being actively involved in all of the traditional stages of work-life development. Findings suggest a deepened or more nuanced view of the principal meanings of work—in particular, identity and social interaction—and highlight several negative aspects of later-life employment such as pension insecurity, unemployment, age discrimination, not having found one's “niche,” and chronic interpersonal difficulties with co-workers. Findings are discussed against the backdrop of a rapidly changing workplace and dramatically shifting work-retirement trajectories in which job stability and predictable retirement are less common.
Assessing How Diversity Affects Students' Interest in Social Change
Authors: Malaney Gary D. , Berger Joseph B.
Published: October 2005

As the country's racial/ethnic minority representation increases, colleges and universities have increasingly sought to diversify their enrollments in order to better prepare all students to live and work in a diverse democracy. However, diversification may negatively affect campus climate and undergraduate peer relations leading to both increased racial tensions and to lower levels of satisfaction and retention for both minority and majority students. This study examined the effects of students' entry characteristics, pre-college environments, and pre-college activities on 3 democratic outcomes that serve as potential indicators of new undergraduate students' readiness to positively engage with diversity: social change self-efficacy, social action engagement, and social leadership skills. Data were collected from 1 of 10 public universities that participated in a 2001 national study that investigated how diversity helps shape students' attitudes and beliefs. The results indicate that students who are more engaged with diversity prior to college are more likely to perceive themselves as ready to proactively engage with diversity as college students.
Internal Dissension Grows as CDC Faces Big Threats to Public Health
Authors: Stein Rob
Published: October 2005

According to current and former CDC officials and several outside experts, the Centers for Disease Control and Prevention is being roiled by internal dissension as it faces such unprecedented threats as bioterrorism, a potential flu pandemic, and the obesity epidemic. The agency has been thrown into turmoil by a combination of factors, including a drawn-out restructuring, the departure of dozens of its most respected scientists, concerns about political interference, and a pending budget cut of nearly $500 million. The impact remains a matter of debate, but the uproar is causing widespread alarm among public health authorities.
Situating Technology Professional Development in Urban Schools
Authors: Meier Ellen B.
Published: October 2005

The Center for Technology and School Change (CTSC) is a research and development center specializing in professional development, evaluation and technology integration research. The goal of the qualitative research reported in this article was to identify factors that strengthen the integration of technology in classrooms in ways that are consistent with larger school improvement themes. The data collected from numerous sources, including the university facilitators and the 100 New York teacher participants with whom they worked in 2003–2004, were analyzed to determine patterns related to the design and delivery of technology professional development. Three concrete themes emerged: the need to understand and address specific teacher concerns in the process of designing technology-integrated curriculum; the value of demonstrating technology's role in assessing student understanding; and the significance of engaging content experts to help teachers address content and pedagogical issues in the technology integration process. These themes inform the larger theoretical framework that underpins the work of the Center.
Behavioral Decision Making and Suggestional Processes: Some Reflections on Common Features
Authors: Molz Guenter
Published: October 2005

Common features between the domains of behavioral decision making and suggestional processes are discussed. These features are allocated to two aspects. First, behavioral decision making and suggestional processes are traditionally considered to provoke inadequate human behavior. In this article arguments are put forward against this interpretation: Actions induced by non-rational decisions and/or by suggestional processes often have adaptive functions. Second, two common thematic issues are discussed (utility functions in behavioral decision making and ambiguity avoidance) which could be investigated empirically within an integrated framework of behavioral decision making and suggestional processes.
Acute Cholestatic Hepatitis Probably Associated with Risperidone
Authors: Tello Francisca Llinares , Prats Carmen Hernández , Ros Nuria Bosacoma , Martínez Enrique Pérez , Grana Eduardo Climent , Polo José Noé Navarro , Baines Juan Pablo Ordovás
Published: October 2005

Objective:

Risperidone is an atypical neuroleptic drug widely used due to the lower incidence and severity of hepatic adverse effects in comparison to phenothiazines. Although idiosyncratic reversible hepatotoxicity may occur in association with risperidone, the interaction with fluoxetine might increase the risk of toxic liver injury in a vulnerable patient.

Methods and Results:

We present a case of acute cholestatic hepatitis probably associated with the use of risperidone after only a few days of therapy in a patient also treated with fluoxetine. The patient, a 64-year-old male, developed a rapid increase in liver enzymes after starting treatment with only four doses of risperidone 2 mg/day.

Conclusions:

We recommend obtaining baseline liver function tests before starting risperidone and regular monitoring to screen patients for liver damage during therapy whenever a patient is also receiving fluoxetine.
Survey Response and its Relationship to Educational Outcomes among First-Year College Students
Authors: Woosley Sherry A.
Published: October 2005

This study focused on survey response, which was defined simply as the completion of a survey. It examined connections between survey response and college student characteristics. It also investigated whether survey response predicted educational outcomes, including retention. The study focused on a cohort of first-year students at a mid-size, 4-year public university. Eighty percent of the students responded to a survey administered during their first semester. Survey response was linked with high school percentile rank and sex. Survey response was also a significant predictor of first semester grade point average and retention to the second year. The findings suggest that survey non-response may be an early warning indicator for first-year students. Also, the findings suggest that research based on surveys may be overlooking a sub-population (non-responders) that could affect the validity of those models.
Gender Differences in Predicting High-Risk Drinking among Undergraduate Students
Authors: Wilke Dina J. , Siebert Darcy Clay , Delva Jorge , Smith Michael P. , Howell Richard L.
Published: October 2005

The purpose of this study was to examine gender differences in college students' high-risk drinking as measured by an estimated blood alcohol concentration (eBAC) based on gender, height, weight, self-reported number of drinks, and hours spent drinking. Using a developmental/contextual framework [1], high-risk drinking is conceptualized as a function of relevant individual characteristics, interpersonal factors, and contextual factors regularly mentioned in the college drinking literature. Individual characteristics include race, gender, and age; interpersonal characteristics include number of sexual partners and having experienced forced sexual contact. Finally, contextual factors include Greek membership, living off-campus, and perception of peer drinking behavior. This study is a secondary data analysis of 1,422 students at a large university in the Southeast. Data were gathered from a probability sample of students through a mail survey. A three-step hierarchical logistic regression analysis showed gender differences in the pathway for high-risk drinking. For men, high-risk drinking was predicted by a combination of individual characteristics and contextual factors. For women, interpersonal factors, along with individual characteristics and contextual factors, predicted high-risk drinking, highlighting the importance of understanding female sexual relationships and raising questions about women's risk-taking behavior. Implications for prevention and assessment are discussed.
The World Bank, Pharmaceutical Policies, and Health Reforms in Latin America
Authors: Homedes Núria , Ugalde Antonio , Forns Joan Rovira
Published: October 2005

Health care systems spend a relatively high percentage of their resources on the purchase of medicines, and the poor spend a disproportionate amount of their income on pharmaceuticals. There is ample evidence in the literature that drugs are very poorly used. World Bank—led health reforms aim at improving equity, efficiency, quality, and users' satisfaction, and it will be difficult to achieve these goals without making medicines accessible and affordable. The purpose of this article is to examine the adequacy of World Bank pharmaceutical policies, as recommended in various Bank documents, for Latin America and to examine the implementation of the policy recommendations. The authors found that the World Bank identified and recommended a set of pharmaceutical policies that matched the needs of the region. But, as revealed through fieldwork and a review of the literature, the recommended pharmaceutical interventions were left out of the health reforms, and most of the loans that included pharmaceutical interventions allocated funds only to the purchase of drugs. The authors formulate four hypotheses that may explain the lack of congruence between the recommended policies and the strategies financed by World Bank health reform loans to the Latin American region.
The Effects on Employment and Wages When Working Mothers Lose Medicaid
Authors: Boushey Heather
Published: October 2005

This study examines the importance of health insurance in promoting employment and wage growth for prime-age mothers. Many mothers on welfare and other low-income mothers are eligible for Medicaid, but as they move up the job ladder, they lose eligibility. Losing work supports limits mothers' ability to stay employed: mothers who make this transition into employer-provided health insurance are nine times more likely to stay employed than mothers who leave Medicaid without this benefit. However, few mothers make the transition from Medicaid to employer-provided health insurance— not because they lack employment but because they do not find jobs that offer health insurance. Between the beginning of 2002 and the end of 2003, 37.2 percent of those on Medicaid left the program, but fewer than a quarter (23.4 percent) of those had employer-provided health insurance.
Cyber-Harassment: A Study of a New Method for an Old Behavior
Authors: Li Tanya Beran Qing
Published: October 2005

A total of 432 students from grades 7–9 in Canadian schools reported their experiences of cyber-harassment, which is a form of harassment that occurs through the use of electronic communications such as e-mail and cell phones. More than two-thirds of students (69%) have heard of incidents of cyber-harassment, about one quarter (21%) have been harassed several times, and a few students (3%) admitted engaging in this form of harassment. In addition, victims of cyber-harassment reported a variety of negative consequences, especially anger and sadness, and had experienced other forms of harassment. These results suggest several avenues of research needed to explain how and why adolescents use technological advances to harass their peers.
Psychological Response to Later Life Widowhood: Coping and the Effects of Gender
Authors: Bennett Kate Mary , Hughes Georgina M. , Smith Philip T.
Published: October 2005

The study examined the effects of psychological response and gender on coping with late life widowhood. Forty-six men and 46 women (55 years +) were interviewed about their experiences of widowhood. Participants were classified as to whether they were coping well or less well. Data were analyzed using grounded theory, content analysis, and three-way loglinear analyses. Loglinear analyses revealed three-way interactions for Gender, Coping, and Response. Men who report feeling upset or selfish are more likely to be coping, as are women who report being comfortable alone. There were two-way interactions between Coping and Response and Gender and Response. Participants who talk to their dead spouse are more likely to be coping than those who do not. Those who “keep themselves to themselves” are more likely not to be coping than those who do not. Gender differences were found in psychological response. Differences were also found between those who coped and those who coped less well. The study has enabled the synthesis of quantitative and qualitative data to present a more complete view of late life widowhood than has previously been possible. In addition, the article draws attention to the importance of distinguishing between the effects of bereavement and those of widowhood.
Examining the Types of Social Support and the Actual Sources of Support in Older Chinese and Korean Immigrants
Authors: Wong Sabrina T. , Yoo Grace J. , Stewart Anita L.
Published: October 2005

This study explored social support domains and actual sources of support for older Chinese and Korean immigrants and compared them to the traditional domains based on mainly White, middle class populations. Fifty-two older Cantonese and Korean speaking immigrants participated in one of eight focus groups. We identified four similar domains: tangible, information/advice, emotional support, and companionship. We also identified needing language support which is relevant for non-English speaking minority populations. Participants discussed not needing emotional support. These Chinese and Korean immigrants had a small number of actual sources of support, relying mainly on adult children for help with personal situations (e.g., carrying heavy groceries, communicating with physicians) and friends for general information/advice (e.g., learning how to speak English, applying for citizenship) and companionship. Immigrant Asians are caught between two different traditions; one that is strongly kinship oriented where needs and desires are subordinated to the interests of the family and one that values independence and celebrates individuality. Despite their reticence in asking for help outside the family, elders are seeking help from other sources, such as ethnic churches and the government.
Student Computer Skills and Attitudes toward Internet-Delivered Instruction: An Assessment of Stability Over Time and Place
Authors: Brinkerhoff Jonathan , Koroghlanian Carol M.
Published: October 2005

With the expansion of Internet-based instruction, research-based guidelines are needed to support faculty decision making during course design to ensure student success and satisfaction with instruction incorporating new delivery technologies. This investigation consisted of two phases. In Phase One, computer skills and attitudes toward Internet-delivered instruction of geographically dispersed students were assessed and those components of an Internet course considered important based on students' demographics including computer experience, computer skills, and prior Internet-delivered course experience were identified. Results revealed shallow levels of computer skills with significant differences by geographic location. Additionally, while students overall were generally neutral toward Internet-based instruction, those with prior Internet-based experience regarded such instruction more positively. Phase Two of this research concerned the rate of change in students' computer skills and attitudes toward Internet-based instruction over time. Results indicated that within a four-year timeframe, student skills and attitudes remained relatively stable with some positive shifts. Implications and suggestions for Internet course design are presented.
Evaluation of the in Touch Training Program for the Management of Alcohol and Other Drug use Issues in Schools
Authors: Midford Richard , Wilkes Deb , Young Deidra
Published: October 2005

In Touch is a professional training program designed to develop staff skills and support structures so as to enable schools to manage alcohol and other drug (AOD) matters in a coordinated manner that maximizes beneficial outcomes for at-risk students, while at the same time maintaining school discipline and community relationships. This study is an evaluation of the impact of the program on alcohol and other drug (AOD) related knowledge, attitudes and activity of participating school staff, and on AOD management practice in their schools. Data from 53 intervention participants and 21 controls were compared at pre- and post-intervention. These data indicated a 46% increase in AOD knowledge among those who participated in In Touch training. Attitudes favorable to integrated, supportive management of AOD issues also increased significantly in this group, as did desirable practice. However, change in school practice was limited. Significantly more schools whose staff participated in In Touch training had a written drug policy at post-intervention, but schools' usual responses to AOD-related incidents were substantially the same. These findings indicate that professional training on the management of AOD matters can change the understanding and practice of individual staff, but if school structures and practice are to be substantially influenced, a broader program is required.
Economic Crisis and Access to Care: Cuba's Health Care System since the Collapse of the Soviet Union
Authors: Nayeri Kamran , López-Pardo Cándido M.
Published: October 2005

This article explores the effects on access to health care in Cuba of the severe economic crisis that followed the collapse of the Soviet Union and the monetary and market reforms adopted to confront it. Economic crises undermine health and well-being. Widespread scarcities and self-seeking attitudes fostered by monetary and market relations could result in differential access to health services and resources, but the authors found no evidence of such differential access in Cuba. While Cubans generally complain about many shortages, including shortages of health services and resources before the economic recovery began in 1995, no interviewees reported systemic shortages or unequal access to health care services or resources; interviewees were particularly happy with their primary care services. These findings are consistent with official health care statistics, which show that, while secondary and tertiary care suffered in the early years of the crisis because of interruptions in access to medical technologies, primary care services expanded unabated, resulting in improved health outcomes. The combined effects of the well-functioning universal and equitable health care system in place before the crisis, the government's steadfast support for the system, and the network of social solidarity based on grassroots organizations mitigated the corrosive effects of monetary and market relations in the context of severe scarcities and an intensified U.S. embargo against the Cuban people.
Masters of Adaptation: Learning in Late Life Adjustments
Authors: Roberson Donald N.
Published: October 2005

The purpose of this research is to understand the relationship between human development in older adults and personal learning. Personal or self-directed learning (SDL) refers to a style of learning where the individual directs, controls, and evaluates what is learned. It may occur with formal classes, but most often takes place in non-formal situations. This study employed a descriptive qualitative design incorporating in-depth, semi-structured interviews for data collection. The sample of 10 purposefully selected older adults from a rural area reflected diversity in gender, race, education, and employment. Data analysis was guided by the constant comparative method. The primary late life adjustments of these older adults were in response to having extra time, changes in family, and social and physical loss. This research also indicated that late life adjustments are a primary incentive for self-directed learning. The results of this study indicated that older adults become masters of adaptation through the use of self-directed learning activities.
The Score Comparability of Computerized and Paper-and-Pencil Formats for K-3 Reading Tests
Authors: Pomplun Mark , Custer Michael
Published: October 2005

This study investigated the equivalence of scores from computerized and paper-and-pencil formats of a series of K-3 reading screening tests. Concerns about score equivalence on the computerized formats were warranted because of the use of reading passages, computer unfamiliarity of primary school students, and teacher versus computer administration of the test. The results indicated that the computerized format produced lower scores than the paper-and-pencil format across all four grades. These difficulty differences could be related to the differences in family income but further research is needed into the causal factors. However, confirmatory factor analysis supported the construct and measurement equivalence of the scores from the two formats.
“I Wish He Had Died in the War”: Suicide Survivors—the Israeli Case
Authors: Avrami Shirley
Published: October 2005

This article presents the findings of a study about the impact of parental suicide on the surviving children, undertaken in Israel in 1999 by a researcher who is a suicide survivor herself. The method employed was qualitative, and in-depth interviews were analyzed inductively. It was found that parental suicide is a meaningful event for the children, and its impact lasts for many years. At the same time, survivors wish to overcome this impact by regaining control over their lives as adults. It was found that the way suicide is perceived by its survivors is socially and contextually related and had to do with the character of the Israeli state and the way death and bereavement are perceived in it.
Adolescents' Beliefs about Marijuana Use: A Comparison of Regular Users, past Users and Never/Occasional Users
Authors: Plancherel Bernard , Bolognini Monique , Stéphan Philippe , Laget Jacques , Chinet Léonie , Bernard Mathieu , Halfon Olivier
Published: October 2005

A questionnaire investigating adolescents' opinions and experiences regarding marijuana use was administered to 163 adolescents and young adults (96 boys and 67 girls) aged 13 to 20 (mean age = 16.8, s.d. = 1.5). Items referred to marijuana and other substances' dangerousness, representations regarding the positive and negative consequences of marijuana use. Responses were compared according to marijuana use status (classified into never/occasional use, current regular use and past regular use). Results show that adolescents' opinions differ according to their experience with marijuana use. Current regular users evaluate marijuana as less dangerous, but alcohol and heroin as more dangerous in comparison with never/occasional and past users. Current and past users are more likely to define marijuana as a medical drug and a plant used in agriculture, and less likely to define it as an illegal drug. Current and past users evaluate marijuana use as a way to cope with stress, to relax to a greater extent than do never/occasional users do. The latter attribute more negative consequences to marijuana use such as diminished driving ability and school performance and a pathway to hard drugs.
Parental Death, Shifting Family Dynamics, and Female Identity Development
Authors: Cait Cheryl-Anne
Published: October 2005

This article is a report of research that explored how the death of a parent influences a woman's identity development. Qualitative methodology and data analysis procedures based on grounded theory were used for the research. Eighteen women who experienced parental death between age 11 and 17, were recruited by convenience sampling. Shifts in family relationships and roles, in part, influenced who these young women became. Many young women were expected to take on a caregiving role to support the surviving parent and replace the deceased. The transition in the relationship between the adolescent girl and surviving parent was an important theme for identity development.
Think Positively and Feel Positively: Optimism and Life Satisfaction in Late Life
Authors: Leung Beeto Wai-Chung , Moneta Giovanni B. , McBride-Chang Catherine
Published: October 2005

This study developed a dispositional path model of life satisfaction for community dwelling Chinese elderly living in Hong Kong. A sample of 117 elderly completed scales measuring life satisfaction, optimism, self-esteem, relationship harmony, self-construals, and perceived/expected health and financial status. Modeling revealed that life satisfaction was predicted by self-esteem and relationship harmony, which in turn were predicted by independent and interdependent self-construals, respectively. In addition, optimism predicted life satisfaction directly and indirectly through self-esteem and relationship harmony. Financial status mediated entirely the effect of optimism on life satisfaction. Health status was predicted by optimism but did not predict life satisfaction. Optimism is a key contributor to subjective well being because it fosters self-esteem, relationship harmony, and positive perceptions of financial conditions.
Instabilities in Lagrangian tracking of bubbles and particles in two‐phase flow
Authors: Göz M. F. , Sommerfeld M. , Laín S.
Published: September 2005

One way to model and simulate the dispersed phase in a two‐phase flow is to track the discrete elements through a fluctuating fluid field by solving their equations of motion. This approach is called Lagrangian. In this frame, it has been shown previously that widely used discretization methods for integrating the particle equation of motion in bubbly flows may lead to artificial instabilities and, eventually, yield spurious oscillations and chaotic behavior by period‐doubling bifurcations. This study extends these previous investigations to consider dispersed two‐phase flow laden with solid particles, which can be heavier or lighter than the fluid in which they are immersed. The main result is that the numerical techniques applied to integrate the particle or bubble equation of motion are stable in the case of heavy particles but must be used very carefully when applied to bubbles or light solid particles in a fluid. During the analysis process, criteria have been established for choosing optimal time steps to simultaneously avoid numerical instabilities and guarantee code efficiency. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Combined heat conduction and heat radiation in one‐dimensional solid
Authors: Maruyama Toshiro , Satake Hiroaki
Published: September 2005

The transient changes in the temperature of a solid material heated by radiation were obtained by numerical calculations using an unsteady one‐dimensional (1‐D) energy equation. The radiative loss of heat from the surface of a heated solid increases with an increase in the radiation flux. Therefore, the net blackbody radiation into a semi‐infinite solid keeps a higher proportion of the initial flux at a lower dimensionless initial flux I0(0)/αk(Tb − T0). In the case of bidirectional radiation to a finite solid, the relatively homogeneous heating can be accomplished at the optical thickness αL ≅ 100. The heating rate is very low at αL ≲ 10−1 resulting from the absorption of a small part of the radiation energy. On the other hand, the heating rate is high at αL ≳ 101, but the heating is limited to a region near the wall, which results in an inhomogeneous temperature profile. At αL ≳ 102, the temperature profiles become identical with that obtained for αL → ∞. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Thermal degradation behaviors of polypropylene with novel silicon‐containing intumescent flame retardant
Authors: Li Qiang , Zhong Hanfang , Wei Ping , Jiang Pingkai
Published: September 2005

The N‐[3‐(dimethoxy‐methyl‐silanyl)‐propyl]‐N′‐ (9‐methyl‐3,9‐dioxo‐2,4,8,10‐tetraoxa‐3,9‐diphospha‐spiro[5.5]undec‐3‐yl)‐ethane‐1,2‐diamine/dimethoxy dimethyl silane copolymer (PSiN II), which simultaneously contains silicon, phosphorus, and nitrogen, is synthesized and incorporated into polypropylene (PP). The flame retardancy is evaluated by the limiting oxygen index value, which is enhanced to 29.5 from 17.4 with 20% total loading of PSiN II. The thermal degradation behavior of PP/PSiN II is investigated by thermogravimetric analysis under N2 and air. The PP/PSiN II sample degrades at 400°C for different amounts of time, and the process of degradation is studied by Fourier transform IR. The morphology of the char formed at 400°C for 10 min is investigated by scanning electron microscopy. The swollen inner structure, close, and smooth outer surface provide a much better barrier for the transfer of heat and mass during fire and good flame retardancy. The thermal stability of PP is improved by incorporation of PSiN II. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2487–2492, 2005
Deswelling stresses and reduced swelling of superabsorbent polymer in composites of fiber and superabsorbent polymers
Authors: Buchholz Fredric L. , Pesce Sandra R. , Powell Cynthia L.
Published: September 2005

The desired performance characteristics of absorbent products such as diapers include a low number of leaks, adequate liquid absorption capacity, and high skin dryness. By measuring the absorption behavior of mixtures of cellulose fluff pulp and superabsorbent polymers in nonimmersed conditions, we identify four major parameters that affect the swelling of the polymer in a composite: the Donnan ion‐exclusion effects of limiting the amount of liquid in contact with the superabsorbent polymer, the restriction of swelling by the physical constraints of the fibrous network that surrounds the polymer particles, the restriction of swelling by the capillary tension provided by the pores between the cellulose fibers, and the osmotic pressure of extracted polyelectrolytes. Swelling of the superabsorbent polymer in composites is always smaller than the value measured by immersion of the polymer followed by centrifugation. Donnan exclusion of ions from the gel phase results in about 16% less swelling than when the polymers are swollen in excess liquid. The swelling restriction imposed by the fiber network, which surrounds the granules, reduces swelling a further 10%. In addition, the presence of small pores between the fibers exerts capillary tension on the polymer and lowers the swelling by another 10%. The external compression of the composite pads does not reduce the extent of swelling of the superabsorbent polymer because the stress is supported by the fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2493–2507, 2005
Preparation and evaluation of a dispersant for gypsum paste from acid hydrolysis lignin
Authors: Matsushita Yasuyuki , Imai Masanori , Tamura Takashi , Fukushima Kazuhiko
Published: September 2005

The preparation of dispersants with carboxyl groups from acid lignin (a byproduct in the saccharification process of woody materials that are renewable resources) was investigated, and their dispersion efficiency was evaluated. In this study, sulfuric acid lignin (SAL) was selected as a representative acid lignin. To convert SAL to water‐soluble polymers, it was first subjected to phenolation with sulfuric acid to enhance its chemical reactivity. The introduction of a carboxy group was carried out with two methods. One was carboxymethylation with bromoacetic acid, and the other was the Mannich reaction with glycine, sarcosine, and iminodiacetic acid. The carboxymethylation product [carboxymethylated phenolized sulfuric acid lignin (CP‐SAL)] with 1.4 carboxymethyl groups per phenolated phenylpropane lignin base unit was soluble in water. The Mannich reaction products were also soluble in water with a lower addition of carboxyl groups than that for CP‐SAL. Surprisingly, all the prepared water‐soluble polymers possessed a higher dispersibility for gypsum paste than commercial lignosulfate. This may be due to the higher molecular weights of acid lignin derivatives. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2508–2513, 2005
Effect of ionic content, solid content, degree of neutralization, and chain extension on aqueous polyurethane dispersions prepared by prepolymer method
Authors: Nanda Ajaya K. , Wicks Douglas A. , Madbouly Samy A. , Otaigbe Joshua U.
Published: September 2005

There are many variables in the preparation of aqueous polyurethane (PU) dispersions. Carboxylic acid content, solid content, degree of pre/postneutralization of the carboxylic acids, and chain extension all impact dispersion particle size, viscosity, pH, molecular weights, and glass transition temperature. This study evaluated the impact of these variables on a given PU dispersion formulation prepared from isophorone diisocyanate, an aliphatic polyester polyol, dimethylol propionic acid, and hexamethylene diamine with triethyl amine as the neutralizing base and N‐methyl pyrrolidone as the cosolvent. Changes in carboxylic acid content, degree of preneutralization, and chain extension were found to have the expected impacts on dispersions properties. Increased ionic content in the dispersion step led to lower particle size and higher viscosity, increased chain extension with its concurrent increase in molecular improved subsequent film properties. Surprising results were obtained by varying the amount of postneutralization and from increased solids content at the time of dispersion. Unexpectedly, both of these variations led to much higher dispersion viscosities and particle size in solution. To have these changes take place, it is theorized that there is a major change in solution morphology caused by these modifications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2514–2520, 2005
Thermodynamic interactions of a copolyester of bisphenol A with terephthalic acid and isophthalic acid with some solvents
Authors: Sakar Dolunay , Cankurtaran Ozlem , Karaman Ferdane Yilmaz
Published: September 2005

The retention diagrams of n‐octane, n‐nonane, n‐decane, n‐butyl acetate, isobutyl acetate, and isoamyl acetate on the polyarylate Ardel D‐100, a copolyester of bisphenol A with terephthalic acid and isophthalic acid, were plotted at temperatures between 120 and 260°C by an inverse gas chromatography technique. The glass‐transition temperature of the copolymer was determined to be 190°C from the discontinuity of these diagrams. The retention diagrams of benzene, ethyl benzene, n‐propyl benzene, isopropyl benzene, and chlorobenzene were also plotted between 200 and 260°C. The specific retention volume, weight fraction activity coefficient, Flory–Huggins polymer–solvent interaction parameter, hard‐core polymer–solvent interaction parameter, and effective exchange energy parameter were determined for the studied solvents. The parameters suggest that the studied aromatic hydrocarbons and aliphatic esters are moderately good solvents and chlorobenzene is a very good solvent for this copolyester, but the n‐alkanes are very poor solvents. The solubility parameter of this copolymer was determined to be 11.6 (cal/cm3)1/2 at room temperature by extrapolation of the values of the solubility parameters from the studied temperatures to 25°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2365–2368, 2005
Properties and application of novel amphoteric polypropylene fabrics
Authors: Mosleh S. , Gawish S. M. , Khalil F. H. , Bieniek R. F.
Published: September 2005

The properties and characterization of a novel series of amphoteric polypropylene fabrics were done by γ‐preirradiation followed by grafting methacrylic acid and then amination using (3‐chloro‐2‐hydroxyl propyl)ammonium derivatives. The new amphoteric grafted PP fabrics have an increase in moisture regain up to 5.5% and100% reduction in growth of Staphylococcus aureus and Klebsiella pneumonia. Also, the dyeability was improved using acid and basic dyes. These new amphoteric textiles properties were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis including TGA and DTA. A slight decrease in the crystallinity was observed by DSC and X‐ray diffraction. The modified PP fabrics can be used for the development of upholstery and medical fabrics with antimicrobial properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2373–2379, 2005
Water absorption in epoxy resins: The effects of the crosslinking agent and curing temperature
Authors: Abdelkader A. F. , White J. R.
Published: September 2005

Epoxy systems were prepared with the same epoxide (diglycidyl ether of bisphenol A) with five different hardeners: 4,4′‐diaminodiphenylmethane (H1), diethylenetriamine (H2), a cycloaliphatic amine based on isophorone diamine (H3), a polyaminoimidazoline‐based hardener (H4), and a polyamidoamine‐based adduct hardener (H5). Samples were subjected to four different postcure treatment temperatures (23, 55, 75, and 150°C). Water absorption kinetics were obtained for each material and for each postcure treatment. The water absorption behaviors for the materials with H1, H2, and H3 were similar, whereas those for H4 and H5 were quite different. This is discussed in terms of the molecular structures of the hardeners. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2544–2549, 2005
New polymer synthesis. XXX. Synthesis and thermal behavior of new organometallic polyketones and copolyketones based on diferrocenylidenecycloheptanone
Authors: Aly Kamal I. , Abdel Monem Maisa I.
Published: September 2005

A new interesting category of organometallic polyketones and copolyketones was synthesized via Friedel–Crafts reactions through the polymerization of 2,7‐bis[(2‐ferrocenyl)methylene] cycloheptanone (II) with different diacid chlorides. The model compound was synthesized by reacting monomer II with benzoyl chloride and characterized by 1H‐NMR, IR, and elemental analyses. The polyketones and copolyketones were insoluble in most organic solvents but easily soluble in concentrated H2SO4. The thermal properties of these polyketones and copolyketones were evaluated and correlated to their structural units by TGA and DTG measurements and had inherent viscosity of 0.32–0.65 dI g−1. Moreover, the electrical conductivity of polyketone Va and copolyketone VI was investigated above the temperature range (300–500 K) and followed an Arrhenius equation with activation energy 2.09 eV. Also, the morphological properties of selected example of polyketones were detected by scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2394–2401, 2005
Synthesis and characterization of magnetorheological polyimide gels
Authors: Fuchs A. , Hu B. , Gordaninejad F. , Evrensel C
Published: September 2005

Magnetorheological polymer gels (MRPGs) are composite fluids containing ferrous particles suspended in a polymer gel. In addition to modification of the carrier fluid, the polymer gel, which includes crosslinked copolyimide (CCPI) and solvent N‐octylpyrrolidone, also changes the surface properties of the ferrous particles, thus reducing the particle settling and improving particle redispersion. The viscosity of MRPGs can be easily adjusted by controlling the concentration of CCPI in the carrier medium. High thermally resistant CCPI is synthesized from dianhydride, diamine, diaminobenzonic acid, and crosslinker and has a high glass transition temperature because the crosslinking ratio can be controlled by the molar ratio of diamine to diaminobenzonic acid. The redispersion and rheological properties are also investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2402–2413, 2005
Effect of PEG additives on properties and morphologies of membranes prepared from poly(2,6‐dimethyl‐1,4‐phenylene oxide) by benzyl bromination and in situ amination
Authors: Tang Beibei , Wu Dan , Xu Tongwen
Published: September 2005

This study investigated the effect of PEG additive on the structure formation and permeation properties of membranes. The membranes were prepared from a bromomethylated poly(2,6‐dimethyl‐1,4‐phenylene oxide)/chlorobenzene/ethanol system using the phase inversion method with PEG as an additive. As expected, PEG with a fixed molecular weight (e.g., PEG 600) acted as a pore‐forming agent, and membrane porosity increased as the PEG content of the casting solution increased. However, when the PEG content was fixed, the effect of PEG on the membrane properties and morphology was largely dependent on its molecular weight. It was found that when the molecular weight of PEG was less than 800, it acted as a pore former, but when the molecular weight of PEG was more than 1000, the pore size and porosity of the resulting membrane decreased. These results can be explained by the membrane‐forming system's thermodynamic and kinetic properties, which can be assessed by coagulation value and viscosity. Furthermore, the membranes were characterized for pure water flux and rejection of solute and by SEM observation. The filtration results agreed well with the SEM observations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2414–2421, 2005
Interaction of microcrystalline chitosan with Ni(II) and Mn(II) ions in aqueous solution
Authors: Bodek Kazimiera Henryka , Kufelnicki Aleksander
Published: September 2005

The protonation constant of the NH2 function was determined by the method of Katchalsky and Spitnik and by the SUPERQUAD fitting procedure. Samples with higher concentrations of chitosan indicated aggregations of polymer chains, which led to a loss in the effective concentration of the ligand (L). It followed, as a result of potentiometric titrations, that an excess of L of microcrystalline chitosan (MCCh) with a deacetylation degree of 0.90 was a complexing agent toward the metal (M), which was Ni(II) or Mn(II). Species ML and ML2 were accepted by SUPERQUAD for both of the M's, where coordination occurred via the amino nitrogen. For Ni(II), however, the hydroxyl oxygen may also have been an electron‐pair donor at lower excesses of MCCh and, by that, made possible the formation of five‐membered chelate rings in the hydroxyl deprotonated MLH‐1 species. The evaluated formation constants were compared with the values known until now for monomeric D‐glucosamine. Additional confirmation of the M–L interaction was determined by the spectrophotometric titration of a Ni(II)–MCCh solution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2572–2577, 2005
Dissolution of condensed tannin with phenol: Optimum reaction parameters and some flow properties
Authors: Samil A. , Alma M. H. , Acemioğlu B.
Published: September 2005

Condensed tannins from the bark of black wattle (Acacia mearnsii L.) were solubilized with phenol using HCl as a catalyst. The optimum reaction parameters (temperature, time, and acid concentration) of the dissolution were determined. The results showed a clear effect on the percentage of reacted phenol and residue tannin by temperature, time and, particularly, acid concentration. It was found that almost 77% of the phenol used could be reacted with the tannin, and about 90% of the tannin could be solubilized into phenol in the presence of HCl (as a catalyst) having a concentration of 5%. The optimum temperature, time, and acid concentration were 160°C, 90 min, and 4%–5%, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2450–2453, 2005
The dynamic mechanical properties of EPDM/Al(OH)3 composites
Authors: Gao Naikui , Li Jianying , Li Shengtao , Peng Zongren
Published: September 2005

The effects of volume fraction, particle size, and surface state of Al(OH)3 fillers on the dynamic mechanical properties of EPDM/Al(OH)3 composites were investigated by dynamic mechanical analysis (DMA). The interfacial structure parameters of EPDM/Al(OH)3 composites were also investigated. The results show that dynamic mechanical property and the glass‐transition process of composites are distinctly influenced by the volume fraction, particle size, and surface state of Al(OH)3 fillers. With the increase of volume fraction and decrease of particle size of Al(OH)3 fillers, the temperature corresponding to the maximum damping factor of composites shifts to a higher temperature with lower peak value and broader half‐peak width. The treatment of fillers with coupling agent can greatly enhance two‐phase interaction and thus improve the dynamic mechanical properties of composites. Consequently, a lower damping factor, broader half‐peak width, and larger apparent activation energy of glass transition can be achieved. In addition, a novel method of calculating the apparent activation energy of composites is put forward based on the DMA method, which has been verified by calculating the apparent activation energy of glass transition of Al(OH)3‐filled EPDM composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2454–2460, 2005