Fabrication of PEM Fuel Cell Bipolar Plates by Indirect SLS

The paper presents a new manufacturing technique involving Selective Laser Sintering (SLS) for proton exchange membrane fuel cell (PEMFC) bipolar plate fabrication. A material system for bipolar plate fabrication was identified to satisfy both the cell performance requirement and SLS operation restriction. Carbonization and liquid epoxy infiltration are subsequently performed following the completion of SLS green bipolar plate. The finished SLS bipolar plate showed impressive surface finish and mechanical strength, and a single fuel cell was assembled with two SLS end plates and membrane electrode assembly (MEA) in between. Various physical property tests were performed with positive results. Fuel cell performance (voltage vs. current density, voltage vs. time, etc.) will be assessed in the near future.Mechanical Engineerin

Improvement of Electrical Conductivity of SLS PEM Fuel Cell Bipolar Plates

Previous work in this research demonstrated the feasibility of fabrication of proton exchange membrane (PEM) fuel cell bipolar plates by an indirect selective laser sintering (SLS) route. Properties of the SLS bipolar plate, such as flexural strength, corrosion resistance and gas impermeability, etc. are quite promising and satisfactory. However, initial results showed that there was still room for the improvement in electrical conductivity. This paper summaries the strategies investigated in an effort to increase the electrical conductivity, among which are: (1) infiltration of brown parts with conductive polymer (2) addition of a liquid phenolic infiltration/re-curing step prior to final sealing and (3) reduction of glassy carbon resistivity by curing process parameter control. Results show that the electrical conductivity value may be improved from 80 S/cm to around 108 S/cm, which is equivalent to a 35% jump, when the phenolic infiltration/re-curing step is applied before final epoxy sealing.Mechanical Engineerin

Assessment for learning : connecting students to their learning

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on March 4, 2008)Vita.Thesis (Ed. D.) University of Missouri-Columbia 2007.Like other schools with similar populations of poor and minority children throughout the nation, the author's school did not produce satisfactory scores on the state's high-stakes testing scheme. The project used an action research model to study how elementary classroom teachers used assessment for learning strategies to help their students more directly connect to curriculum goals and objectives. Furthermore, the author examined his own practice in facilitating the learning of others. Four elementary teachers agreed to participate together in the study. Data was collected from the transcribed audio recordings of the group's meetings, observation notes, journal reflections and final interviews. The teachers demonstrated their capacity to use assessment strategies to engage their students. The author learned the value of listening as means of affirming the teachers' efforts. However, the most salient finding of the project dealt with the collaboration of the participating teachers, who valued the opportunity to collegially discuss their work in a non-threatening, supportive situation. Implications for conducting similar research are discussed as well.Includes bibliographical reference

Child Rights and Social Justice Framework for Analyzing Public Policy Related to HPV Vaccine

Human papilloma virus (HPV) is the most common viral infection of the reproductive tract and a well-established cause of cervical, anal, and oropharyngeal cancers in both women and men worldwide. Despite data that supports HPV vaccine as an effective measure to prevent such cancers, vaccine uptake has not been optimal in many countries. In the United States (US) for example, rates have stagnated over the past few years and only one-third of adolescents are fully immunized, in contrast to other adolescent vaccines such as Tdap and meningococcal that have double the rates of uptake. Current approaches to HPV vaccine education and delivery have not been successful at improving immunization rates. In this article we propose the implementation of a child rights, social justice, and health equity-based approach to HPV vaccine policy. This approach would promote youth’s participation in medical decision-making and advance policies that allow for independent consent to HPV vaccination. We postulate that by empowering youth to be involved in issues pertaining to their health and well-being, they will be more likely to explore and discuss information about HPV with others, and be able to make informed decisions related to HPV vaccine

Evaluating Tisza River Basin Development Plans Using Multiattribute Utility Theory

Selecting a plan to develop the water resources of a region involves the consideration of economic, environmental, social, and technical objectives. Twelve attributes are defined to indicate the degree to which these objectives are achieved in the Tisza River basin of Hungary. A preliminary multiattribute utility function is assessed over these attributes. This is combined with existing information describing the possible consequences of five alternative development plans to yield an overall rating of their desirability. The utility function explicitly indicates the preference tradeoffs among attributes. Discussion indicates further uses of the utility function in the planning and evaluation processes

Inpatient urine cultures are frequently performed without urinalysis or microscopy: Findings from a large academic medical center

OBJECTIVETo describe the frequency of urine cultures performed in inpatients without additional testing for pyuriaDESIGNRetrospective cohort studySETTINGA 1,250-bed academic tertiary referral centerPATIENTSHospitalized adultsMETHODSThis study included urine cultures drawn on 4 medical and 2 surgical wards from 2009 to 2013 and in the medical and surgical intensive care units (ICUs) from 2012 to 2013. Patient and laboratory data were abstracted from the hospital’s medical informatics database. We identified catheter-associated urinary tract infections (CAUTIs) in the ICUs by routine infection prevention surveillance. Cultures without urinalysis or urine microscopy were defined as “isolated.” The primary outcome was the proportion of isolated urine cultures obtained. We used multivariable logistic regression to assess predictors of isolated cultures.RESULTSDuring the study period, 14,743 urine cultures were obtained (63.5 cultures per 1,000 patient days) during 11,820 patient admissions. Of these, 2,973 cultures (20.2%) were isolated cultures. Of the 61 CAUTIs identified, 31 (50.8%) were identified by an isolated culture. Predictors for having an isolated culture included male gender (adjusted odds ratio [aOR], 1.22; 95%; confidence interval [CI], 1.11–1.35], urinary catheterization (aOR, 2.15; 95% CI, 1.89–2.46), ICU admission (medical ICU aOR, 1.72; 95% CI, 1.47–2.00; surgical ICU aOR, 1.82; 95% CI, 1.51–2.19), and obtaining the urine culture ≥1 calendar day after admission (1–7 days aOR, 1.91; 95% CI. 1.71–2.12; &gt;7 days after admission aOR, 2.81; 95% CI, 2.37–3.34).CONCLUSIONSIsolated urine cultures are common in hospitalized patients, particularly in patients with urinary catheters and those in ICUs. Interventions targeting inpatient culturing practices may improve the diagnosis of urinary tract infections.Infect Control Hosp Epidemiol2017;38:455–460</jats:sec