The Effect of Thin Film Adhesives on Mode II Interlaminar Fracture Toughness in Carbon Fiber Composites with Shape Memory Alloy Inserts.

A single sheet of nickel-titanium (NiTi) shape memory alloy (SMA) was introduced within an IM7/8552 polymer matrix composite (PMC) panel in conjunction with multiple thin film adhesives to promote the interfacial bond strength between the SMA and PMC. End notched flexure (ENF) testing was performed in accordance to ASTM D7905 method for evaluation of mode II interlaminar fracture toughness (G) of unidirectional fiber-reinforced polymer matrix composites. Acoustic emissions (AE) were monitored during testing with two acoustic sensors attached to the specimens.

The Effect of Thin Film Adhesives on Mode I Interlaminar Fracture Toughness in Carbon Fiber Composites with Shape Memory Alloy Inserts.

Shape Memory Alloy (SMA) was placed within Polymer Matrix Composite (PMC) panels alongside film adhesives to examine bonding. Double cantilever beam (DCB) testing was performed using ASTM D5528. C-scanning was performed before testing, modal acoustic emissions (MAE) were monitored during testing, and microscopy performed post-test.

The Effects of Fiber Orientation and Adhesives on Tensile Properties of Carbon Fiber Reinforced Polymer Matrix Composite with Embedded Nickel-Titanium Shape Memory Alloys.

Tensile tests of Nickel-titanium (NiTi) shape memory alloys (SMA) embedded within carbon fiber reinforced polymer matrix composite (CFRP/PMC) laminates were evaluated with simultaneous monitoring of modal acoustic emissions (MAE). Three different layup configurations utilizing two different thin film adhesives were applied to bond the materials. Ultimate tensile strengths, strains, and moduli were obtained along with cumulative AE energy of events and specimen failure location.

Tailoring properties of cross-linked polyimide aerogels for better moisture resistance, flexibility, and strength.

Combinations of rigid and flexible aromatic diamines were used to tailor the properties of octa(aminophenyl)-silsesquioxane (OAPS) cross-linked polyimide aerogels. 2,2'-Dimethylbenzidine (DMBZ) or p-phenylenediamine (PPDA) was used in combination with the more-flexible diamine, 4,4'-oxydianiline (ODA). The amount of rigid diamine was varied from 0% to 100% of the total diamines in the backbone.

Mechanically strong, flexible polyimide aerogels cross-linked with aromatic triamine.

Polyimide gels are produced by cross-linking anhydride capped polyamic acid oligomers with aromatic triamine in solution and chemically imidizing. The gels are then supercritically dried to form nanoporous polyimide aerogels with densities as low as 0.14 g/cm(3) and surface areas as high as 512 m(2)/g.

Polyimide aerogels cross-linked through amine functionalized polyoligomeric silsesquioxane.

We report the first synthesis of polyimide aerogels cross-linked through a polyhedral oligomeric silsesquioxane, octa(aminophenyl)silsesquioxane (OAPS). Gels formed from polyamic acid solutions of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), bisaniline-p-xylidene (BAX) and OAPS were chemically imidized and dried using supercritical CO(2) extraction to give aerogels having density around 0.1 g/cm(3).

Structure-property relationships in porous 3D nanostructures: epoxy-cross-linked silica aerogels produced using ethanol as the solvent.

Cross-linking silica aerogels with organic groups has been shown to improve the strength over un-cross-linked aerogels by as much as 2 orders of magnitude. Previous cross-linking chemistry has been developed using solvents specifically chosen to dissolve the monomers and accommodate the reaction temperature. Because the process of making the aerogels requires so much solvent, it is of interest to consider less toxic solvents such as ethanol to increase safety and enhance scale up.

Statistical methodology for screening studies with qualitative/quantitative mixtures.

A statistical method for designing screening studies involving several experimental treatments compared to a standard treatment is developed. The screening study identifies the most promising experimental treatments, which then undergo more rigorous evaluation in a future, larger study. The technique is especially relevant for biopharmaceutical research and development in which phase II clinical trials are conducted to identify the most promising drug regimens, which then move on to phase III of clinical development.

Barriers to the use of preventive health care services for children.

This article describes findings from interviews of parents targeted for outreach efforts that encouraged them to use Medicaid's Early and Periodic Screening, Diagnosis and Treatment(EPSDT) Program. Begun in the 1970s, the EPSDT program held out the promise of ensuring that needy children would receive comprehensive preventive care. With only one-third of eligible children in the United States receiving EPSDT checkups, the program has yet to fulfill its promise.

Diversity in the rural poor: differences between households with and without telephones.

Differences between households with and without phones in the United States as a whole are well documented, but these differences, and their implications for nursing practice and research, have received little attention in nursing publications. This article 1) reviews findings from national studies of these differences and 2) reports on a nursing study that examined such differences specifically in a random sample (N = 2,053) of low-income families having children eligible for but not using the well-child services of the Medicaid program in rural North Carolina. The study was part of a randomized trial of nursing interventions to encourage parents to use these services.

Health outcomes of children receiving EPSDT checkups: a pilot study.

This pilot study used medical records to examine the health outcomes of children receiving care in Medicaid's Early and Periodic Screening, Diagnosis and Treatment (EPSDT) program. Medical records from 76 children seen for EPSDT visits during a 6-month period were reviewed to assess whether health problems were identified and whether treatment, follow-up, or referral care was provided. Health problems were identified for 43% of the children; 22% received treatment, and 18% were referred for specialty care.

Increasing Medicaid child health screenings: the effectiveness of mailed pamphlets, phone calls, and home visits.

Objectives: A randomized controlled trial was conducted to test the effectiveness and cost effectiveness of three outreach interventions to promote well-child screening for children on Medicaid.

Methods: In rural North Carolina, a random sample of 2053 families with children due or overdue for screening was stratified according to the presence of a home phone. Families were randomly assigned to receive a mailed pamphlet and letter, a phone call, or a home visit outreach intervention, or the usual (control) method of informing at Medicaid intake.

HIV-related concerns and educational needs of public health nurses in a rural state.

An anonymous questionnaire was completed by 369 nurses in public health departments in a rural Southeastern state to examine the relationship between nurses' prior HIV training and their HIV-related knowledge, attitudes, concerns, and perceived training needs. The survey was conducted in three predominantly urban counties with the highest number of AIDS cases and in 38 rural counties with two or fewer reported AIDS cases. Knowledge answers were generally 70%-90% correct and attitudes more favorable than unfavorable.

Obtaining telephone numbers for a rural Medicaid population: issues for outreach and research.

This study examined the accuracy and costs of determining whether rural, low-income Medicaid recipients did or did not have a phone, and of obtaining phone numbers for those who did. For a random sample of 209 families, we compared phone information obtained from phone books and directory assistance with information obtained from department of social services (DSS) records. DSS records identified 51% of the sample as having phones, compared with 19%-25% for phone books and directory assistance.

Reporting of instrument validity and reliability in selected clinical nursing journals, 1989.

Before research findings are applied to practice, the quality of the research must be assessed so that flawed research does not lead inadvertently to flawed practice. Two critical indicators of research quality are the validity and reliability of the data collection instruments. This article summarizes the principles of instrument validity and reliability and identifies deviations from these principles in a random sample of 55 research studies published in 1989 in five refereed nursing journals targeted toward practicing clinicians.

Increasing mammography utilization: a controlled study.

Background: Despite the effectiveness of breast cancer screening for women older than 50 years of age, only about one third of these women in the United States receive annual mammography.

Purpose: This study was designed to determine if a community-wide intervention could increase use of mammography screening for breast cancer. Secondary end points were determination of changes in women's knowledge and attitudes toward mammography and physicians' self-reported screening practices.

Relationship of object loss during development to hypothalamic-pituitary-adrenal axis function during major affective illness later in life.

Although many studies have attempted to determine whether early object loss influences the risk of developing major affective illness in adulthood, there are few empirical data relating early loss to subsequent hypothalamic-pituitary-adrenal (HPA) axis dysfunction in adulthood. Forty-five psychiatric inpatients admitted for an active major affective illness, all of whom had a previous history of a significant permanent object loss (by death only), were studied retrospectively in this preliminary investigation to examine whether the type and timing of object loss experienced earlier in life would discriminate affectively ill patients who exhibit HPA dysfunction. Several loss variables were found to be statistically significant predictors of cortisol responses following glucocorticoid challenge.

Evidence for normal feedback inhibition of triiodothyronine on the thyrotropin (TSH) response to thyrotropin-releasing hormone (TRH) in abstinent male alcoholics.

Disturbances in the hypothalamic-pituitary-thyroid (HPT) axis have been reported in abstinent, noncirrhotic alcoholics, including a reduction in thyrotropin (TSH) response to thyrotropin-releasing hormone (TRH) and reductions in triiodothyronine (T3). Some evidence has suggested that a portion of alcoholics may also exhibit a disturbance in the feedback inhibition of thyroid hormone on TSH release. To evaluate the function of the HPT axis negative feedback system in abstinent, noncirrhotic alcoholic men we compared the TSH response with TRH before and after a standard suppressive dose of T3.

Measuring the use of mammography: two methods compared.

Population studies often estimate mammography use using women's self-reports. In one North Carolina county, we compared self-report surveys with a second method--counting mammograms per population--for 1987 and 1989. Estimates from self-reports (35% in 1987, 55% in 1989) were considerably higher than those from mammogram counts (20% in 1987, 36% in 1989).

Increasing participation by private physicians in the EPSDT Program in rural North Carolina.

This study evaluated a method to increase physicians' participation in Early and Periodic Screening, Diagnosis and Treatment (EPSDT), a preventive health care program for Medicaid eligible children. Use of EPSDT can improve children's health status and reduce health care costs. Although the potential benefits of EPSDT are clear, the program is underused; low rates of participation by private physicians contribute to underuse.

Circulating natural killer cell phenotypes in men and women with major depression. Relation to cytotoxic activity and severity of depression.

The effects of major depression on peripheral blood natural killer cell phenotypes and natural killer cell activity were studied by comparing depressed and normal control subjects. Depressed subjects exhibited (1) significant reductions in Leu-11 (CD16) natural killer effector cells and natural killer cell activity and (2) a dissociation of the normal positive correlation between the percentage of Leu-11 cells and natural killer cell activity. These findings suggest that alterations in the availability and the killing capacity of circulating Leu-11 natural killer cells appear to be responsible for depression-related reductions in natural killer cell activity.

Abnormal diurnal variation in circulating natural killer cell phenotypes and cytotoxic activity in major depression.

This investigation tested the hypothesis that depressed patients have abnormal diurnal variation of natural killer (NK) cell measures. The diurnal variation of levels of Leu-11 NK cells and NK cytotoxic activity was significantly less in 24 patients with major depression than in 24 normal comparison subjects. These findings provide evidence that aspects of immune, as well as neural and endocrine, chronobiology are abnormal in depression.

Self-help quit smoking interventions: effects of self-help materials, social support instructions, and telephone counseling.

Smokers requesting self-help materials for smoking cessation (N = 2,021) were randomized to receive (a) an experimental self-quitting guide emphasizing nicotine fading and other nonaversive behavioral strategies, (b) the same self-quitting guide with a support guide for the quitter's family and friends, (c) self-quitting and support guides along with four brief counselor calls, or (d) a control guide providing motivational and quit tips and referral to locally available guides and programs. Subjects were predominantly moderate to heavy smokers with a history of multiple previous quit attempts and treatments. Control subjects achieved quit rates similar to those of smokers using the experimental quitting guide, with fewer behavioral prequitting strategies and more outside treatments.