bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Human Error Probability Assessment Using Fuzzy Modeling
Authors: Ung Shuen‐Tai , Shen Wei‐Min
Published: December 2010

Human error is one of the significant factors contributing to accidents. Traditional human error probability (HEP) studies based on fuzzy number concepts are one of the contributions addressing such a problem. It is particularly useful under circumstances where the lack of data exists. However, the degree of the discriminability of such studies may be questioned when applied under circumstances where experts have adequate information and specific values can be determined in the abscissa of the membership function of linguistic terms, that is, the fuzzy data of each scenario considered are close to each other. In this article, a novel HEP assessment aimed at solving such a difficulty is proposed. Under the framework, the fuzzy data are equipped with linguistic terms and membership values. By establishing a rule base for data combination, followed by the defuzzification and HEP transformation processes, the HEP results can be acquired. The methodology is first examined using a test case consisting of three different scenarios of which the fuzzy data are close to each other. The results generated are compared with the outcomes produced from the traditional fuzzy HEP studies using the same test case. It is concluded that the methodology proposed in this study has a higher degree of the discriminability and is capable of providing more reasonable results. Furthermore, in situations where the lack of data exists, the proposed approach is also capable of providing the range of the HEP results based on different risk viewpoints arbitrarily established as illustrated using a real‐world example.
Phosphate‐binding efficacy of crushed vs. chewed lanthanum carbonate in hemodialysis patients
Authors: HOW Priscilla P. , ANATTIWONG Prathana , MASON Darius L. , ARRUDA Jose A. , LAU Alan H.
Published: December 2010

Lanthanum carbonate, a chewable noncalcium‐containing phosphorus (P) binder, is useful for treating secondary hyperparathyroidism in patients who have hypercalcemia and cannot swallow whole tablets. However, some patients cannot chew tablets or prefer to crush and mix them with food. This study was conducted to determine the P‐binding efficacy of crushed lanthanum and compare it with chewed lanthanum in hemodialysis (HD) patients. After a 1‐week washout period, 11 hemodialysis patients (7 men, 4 women) were randomized to receive, in a crossover fashion, lanthanum 1000 mg 3 times daily chewed with meals and lanthanum 1000 mg 3 times daily crushed into a fine powder, mixed with applesauce and taken with meals, for 4 weeks each. Serum P was measured at the end of each washout (baseline) and weekly during treatment. Changes in serum P from baseline for crushed lanthanum were compared with chewed lanthanum using paired sample t test. Administration of crushed lanthanum resulted in a significant reduction in serum P from baseline (P reduction [mg/dL] for crushed lanthanum in week 1: 2.1 ± 0.4, week 2: 1.7 ± 0.5, week 3: 1.7 ± 0.5, week 4: 1.7 ± 0.4, P<0.05). No statistically significant differences were observed in serum P reduction from baseline and serum P attained during treatment with crushed when compared with chewed lanthanum. Crushed lanthanum is effective in reducing serum P and have similar P‐binding efficacy to chewed lanthanum. Crushing lanthanum and mixing it with food can thus be an option for patients who are unable to chew or swallow whole tablets.
Nonmarital Sex and Condom Knowledge among Ethiopian Young People: Improved Estimates Using a Nonverbal Response Card
Authors: Lindstrom David P. , Belachew Tefera , Hadley Craig , Hattori Megan Klein , Hogan Dennis , Tessema Fasil
Published: December 2010

The accurate assessment of risky sexual behaviors and barriers to condom use is essential to reduce the spread of HIV/AIDS. This study tests a new nonverbal response‐card method for obtaining more accurate responses to sensitive questions in the context of face‐to‐face interviewer‐administered questionnaires in a survey of 1,269 Ethiopian young people aged 13–24. Comparisons of responses between a control group that provided verbal responses and an experimental group that used the card indicate that the prevalence of nonmarital sexual intercourse may be two times higher and knowledge of condom access may be 22 percent lower in the study than typical population‐survey methods suggest. These results suggest that our nonverbal response‐card method yields less biased estimates of risky adolescent sexual behavior and perceived access to condoms than those derived from conventional face‐to‐face interviewer‐administered surveys, and that this method provides an effective, easy‐to‐use, low‐cost alternative.
Providers' Views Concerning Family Planning Service Delivery to HIV‐positive Women in Mozambique
Authors: Hayford Sarah R. , Agadjanian Victor
Published: December 2010

This study explores challenges and obstacles in providing effective family planning services to HIV‐positive women as described by staff of maternal and child health (MCH) clinics. It draws upon data from a survey of service providers carried out from late 2008 to early 2009 in 52 MCH clinics in southern Mozambique, some with and some without HIV services. In all clinics, surveyed providers reported that practical, financial, and social barriers made it difficult for HIV‐positive clients to follow protocols to prevent mother‐to‐child transmission of the virus. Likewise, staff were skeptical of their seropositive clients' ability to adhere to recommendations to cease childbearing and to use condoms consistently. Providers' recommendations to HIV‐positive clients and their assessment of barriers to adherence did not depend on availability of HIV services. Although integration of HIV and reproductive health services is advancing in Mozambique, service providers do not feel that they can influence the behaviors of HIV‐positive women effectively.
THE TRUTH ABOUT THE GERMAN “JOB MIRACLE”: A REPORT ON THE INNER LIFE OF A “JOB WONDERLAND”
Authors: Jeremias Ralf
Published: December 2010

Everywhere in the industrialized and postindustrial countries of the West, unemployment is very high due to the worldwide economic crisis, in some cases 10 percent or more. In early July 2010 the U.S. unemployment rate was 9.5 percent, yet Germany has apparently been enjoying a minor “job miracle.” In June 2010 the German unemployment rate was 7.5 percent, with only 3,153,000 officially unemployed—the rate has not been this low in June for eighteen years. How can it be that almost all countries are currently experiencing high unemployment rates, while Germany is enjoying a comparatively low rate? This article examines the reasons for and background of this apparent “job miracle.” These include economic developments, statistical idiosyncrasies, such as “improving” the numbers, the liberalization of the labor market, and also psychological factors. That there really is a German “job miracle” can definitely be challenged.
Age of Onset and Sexual Orientation in Transsexual Males and Females
Authors: Nieder Timo O. , Herff Melanie , Cerwenka Susanne , Preuss Wilhelm F. , Cohen-Kettenis Peggy T. , De Cuypere Griet , Hebold Haraldsen Ira R. , Richter-Appelt Hertha
Published: December 2010

Introduction

With regard to transsexual developments, onset age (OA) appears to be the starting point of different psychosexual pathways.

Aim

To explore differences between transsexual adults with an early vs. late OA.

Methods

Data were collected within the European Network for the Investigation of Gender Incongruence using the Dutch Biographic Questionnaire on Transsexualism (Biografische Vragenlijst voor Transseksuelen) and a self-constructed score sheet according to the DSM-IV-TR (Diagnostic and Statistical Manual, Fourth Edition, Text Revision) criteria of Gender Identity Disorder (GID) and Gender Identity Disorder in Childhood (GIDC). One hundred seventy participants were included in the analyses.

Main Outcome Measures

Transsexual adults who, in addition to their GID diagnosis, also fulfilled criteria A and B of GIDC (“a strong cross-gender identification,”“persistent discomfort about her or his assigned sex”) retrospectively were considered as having an early onset (EO). Those who fulfilled neither criteria A nor B of GIDC were considered as having a late onset (LO). Participants who only fulfilled criterion A or B of GIDC were considered a residual (RES) group.

Results

The majority of female to males (FtMs) appeared to have an early OA (EO = 60 [77.9%] compared to LO = 10 [13%] and to RES = 7 [9.1%]). Within male to females (MtFs), percentages of EO and LO developments were more similar (EO = 36 [38.7%], LO = 45 [48.4%], RES = 12 [12.9%]). FtMs presented to gender clinics at an earlier age than MtFs (28.04 to 36.75). The number of EO vs. LO transsexual adults differed from country to country (Belgium, Germany, the Netherlands, Norway).

Conclusion

OA has a discriminative value for transsexual developments and it would appear that retrospective diagnosis of GIDC criteria is a valid method of assessment. Differences in OA and sex ratio exist between European countries.
Predictors of Sexual Desire Disorders in Women
Authors: Brotto Lori A. , Petkau A. John , Labrie Fernand , Basson Rosemary
Published: December 2010

Introduction

A historic belief was that testosterone was the “hormone of desire.” However, recent data, which show either minimal or no significant correlation between testosterone levels and women’s sexual desire, suggest that nonhormonal variables may play a key role.

Aim

To compare women with hypoactive sexual desire disorder (HSDD) and those with the recently proposed more symptomatic desire disorder, Sexual Desire/Interest Disorder (SDID), on the relative contribution of hormonal vs. nonhormonal variables.

Methods

Women with HSDD (N = 58, mean age 52.5) or SDID (N = 52, mean age 50.9) participated in a biopsychosocial assessment in which six nonhormonal domains were evaluated for the degree of involvement in the current low desire complaints. Participants provided a serum sample of hormones analyzed by gas chromatography-mass spectrometry or liquid chromatography/mass spectrometry/mass spectrometry.

Main Outcome Measures

Logistic regression was used to assess the ability of variables (nonhormonal: history of sexual abuse, developmental history, psychosexual history, psychiatric status, medical history, and sexual/relationship-related factors; hormonal: dehydroepiandrosterone [DHEA], 5-diol, 4-dione, testosterone, 5-α-dihydrotestosterone, androsterone glucuronide, 3α-diol-3G, 3α-diol-17G, and DHEA-S; and demographic: age, relationship length) to predict group membership.

Results

Women with SDID had significantly lower sexual desire and arousal scores, but the groups did not differ on relationship satisfaction or mood. Addition of the hormonal variables to the two demographic variables (age, relationship length) did not significantly increase predictive capability. However, the addition of the six nonhormonal variables to these two sets of predictors significantly increased ability to predict group status. Developmental history, psychiatric history, and psychosexual history added significantly to the predictive capability provided by the basic model when examined individually.

Conclusions

Nonhormonal variables added significant predictive capability to the basic model, highlighting the importance of their assessment clinically where women commonly have SDID in addition to HSDD, and emphasizing the importance of addressing psychological factors in treatment.
Involvement of Sphingosine-1-Phosphate/RhoA/Rho-Kinase Signaling Pathway in Corporal Fibrosis Following Cavernous Nerve Injury in Male Rats
Authors: Cho Min Chul , Park Kwanjin , Chai Ji Sun , Lee Sun Hee , Kim Soo Woong , Paick Jae-Seung
Published: December 2010

Introduction

Postprostatectomy erectile dysfunction (ED) is thought to be due primarily to injury to cavernous nerve (CN) during surgery. The molecular mechanisms leading to ED after CN injury are poorly understood.

Aim

We determined whether transforming growth factor-β1 (TGF-β1), sphingosine-1-phosphate (S1P) and RhoA/Rho-kinase (ROCK) signaling pathways were involved in corporal fibrosis after bilateral CN injury in rats.

Methods

Forty-eight 10-week-old male Sprague-Dawley rats were equally divided into the following four groups: normal control group (C); sham surgery group (S); bilateral CN crush injury group (I); and bilateral CN transection group (T). Within each of the four groups, two subgroups were analyzed as a function of time (1 and 8 weeks postoperatively).

Main Outcome Measures

Penile tissue was processed for immunoblot (RhoA, ROCK1, phospho-myosin phosphatase target subunit [MYPT1]), reverse transcription-polymerase chain reaction (RT-PCR) (TGF-β1, sphingosine kinase type 1 [SphK1], and S1P2), immunohistochemistry (alpha smooth muscle actin [α-SMA]), and Masson’s trichrome staining.

Results

At 1 and 8 weeks postoperatively, the I and T groups had a significantly decreased smooth muscle cell/collagen ratio, the expression of α-SMA and phospho-MYPT1 compared to the C group. Densitometry revealed a significantly higher expression of RhoA and ROCK1 in the T group compared to the C group at 1 and 8 weeks postoperatively. For the I group, the expression of RhoA significantly increased starting from 1 week postoperatively, but the expression of ROCK1 significantly increased as late as 8 weeks following injury. The expression of TGF-β1 and S1P2 mRNA in the I or T group remained significantly increased up to 8 weeks compared to the C group, despite significant reduction at 8 weeks compared to 1 week postoperatively. The expression of SphK1 mRNA in the I and T groups was significantly increased at 1 week but not 8 weeks postoperatively.

Conclusions

Our data suggest that S1P and RhoA/ROCK1 signaling may be involved in corporal fibrosis associated with loss of smooth muscle through coordination with TGF-β1 after CN injury.
Comparison of the First Intake of Vardenafil and Tadalafil in Patients with Diabetic Neuropathy and Diabetic Erectile Dysfunction
Authors: Kamenov Zdravko Asenov
Published: December 2010

Introduction

Diabetic neuropathy (DN) is one of the key pathogenetic factors for diabetic erectile dysfunction (DED).

Aim

The aim of this study was to compare the effect of the first intake of tadalafil and vardenafil in men with DN and DED.

Methods

In this comparative prospective randomized study were included 49 phosphodiesterase type 5 (PDE5) inhibitor-naïve men (80% type 2 diabetes). DN was assessed by a modified Neuropathy Disability Score (NDS ≥ 3). Each patient received two pills containing 20 mg of either tadalafil (N = 24) or vardenafil (N = 25). They had to be taken after discharge from the hospital at a time interval of at least 3 and 1 day, respectively, and 1 to 6 hours before the intended sexual activity.

Main Outcome Measures

The treatment efficacy was evaluated by the changes in the erectile domain of International Index of Erectile Function (IIEF), Sexual Encounter Profile Question 2 (SEP2) and 3 (SEP3), and the Global Assessment Question (GAQ).

Results

For all patients, IIEF increased from 12.6 ± 6.8 to 19.6 ± 9.0 (P < 0.001) points after treatment. The number of men with positive answers on SEP2 increased from 27 (55.1%) to 38 (77.6%), on SEP3 from 7 (14.3%) to 30 (61.2%). Thirty-one (63.3%) evaluated the effect of the drugs as beneficial (GAQ). No significant efficacy difference between tadalafil and vardenafil was observed. The initial indicators for DED, as well as the treatment efficacy, correlated highly significant with NDS. Both PDE5 inhibitors were well tolerated. Before entering the study, 28% of men have seen a physician, but only 57.1% of them have started treatment.

Conclusions

In this study design, tadalafil and vardenafil are equally effective with the first intake in patients with diabetes and DN. Baseline indicators of erectile dysfunction and the ones verifying the effect of the treatment show significant correlation with the DN indicator—NDS. Tadalafil and vardenafil are well tolerated with no serious side effects.
Ice chemistry in massive young stellar objects: the role of metallicity
Authors: Oliveira J. M. , van Loon J. Th. , Sloan G. C. , Indebetouw R. , Kemper F. , Tielens A. G. G. M. , Simon J. D. , Woods Paul M. , Meixner M.
Published: December 2010

We present the comparison of the three most important ice constituents (water, CO and CO2) in the envelopes of massive young stellar objects (YSOs), in environments of different metallicities: the Galaxy, the Large Magellanic Cloud (LMC) and, for the first time, the Small Magellanic Cloud (SMC). We present observations of water, CO and CO2 ice in four SMC and three LMC YSOs (obtained with Spitzer-IRS and VLT/ISAAC). While water and CO2 ice are detected in all Magellanic YSOs, CO ice is not detected in the SMC objects. Both CO and CO2 ice abundances are enhanced in the LMC when compared to high-luminosity Galactic YSOs. Based on the fact that both species appear to be enhanced in a consistent way, this effect is unlikely to be the result of enhanced CO2 production in hotter YSO envelopes as previously thought. Instead we propose that this results from a reduced water column density in the envelopes of LMC YSOs, a direct consequence of both the stronger UV radiation field and the reduced dust-to-gas ratio at lower metallicity. In the SMC the environmental conditions are harsher, and we observe a reduction in CO2 column density. Furthermore, the low gas-phase CO density and higher dust temperature in YSO envelopes in the SMC seem to inhibit CO freeze-out. The scenario we propose can be tested with further observations.
EVALUATION OF SOME PHYSICAL–CHEMICAL PROPERTIES OF WHEAT, CASSAVA, MAIZE AND COWPEA FLOURS FOR BREAD MAKING
Authors: OLADUNMOYE O.O. , AKINOSO R. , OLAPADE A.A.
Published: December 2010

Both the physical and chemical characteristics of flours affect their quality and the subsequent products from them. The comparative evaluation of particle size, moisture content, bulk density, color, water absorption capacity, pasting viscosity, fat and protein contents of wheat, cassava, maize and cowpea flours were determined using standard methods. Composite breads were produced from 50:30:20, 60:20:20, 70:20:10; 80:10:10, 85:10:5 and 90:5:5 ratio of wheat–cassava/maize–cowpea flours, respectively. Breads produced were subjected to sensory and proximate analyses. The particle size, moisture content, bulk density, water absorption capacity, fat and protein contents of wheat, cassava, maize and cowpea flours are as follows: 154–343 µm, 13.3–14.9% db, 327.4–497.5 kg/m3, 31.9–221.8 g/g, 1.01–2.3% and 2.6–19.39% . Wheat flour had the lowest pasting temperature of 56.1C. Significance differences at P < 0.05 were recorded between most of the properties of the flours. Composite bread of 85% wheat, 10% cassava, 5% cowpea; 90% wheat, 5% cassava, 5% cowpea; and 90% wheat, 5% maize, 5% cowpea were accepted by a sensory evaluation panelist. Substitution with cowpea fruit improved the protein content of the bread.

PRACTICAL APPLICATIONS

In developing countries such as Nigeria, this study is one of the efforts directed toward identifying nonwheat sources that could be used as substitutes to wheat flour in bread making, and hence affects savings in foreign exchange by reducing wheat importation. Published works on physical and chemical properties of cassava, maize and cowpea flours provides information for researchers on this area of study. With these, the behavior of flours can be predicted. All varieties of the three crops used for the experiment are commercially cultivated in Nigeria; hence the research findings can be easily adapted in commercial bread production. These will result in increased demand for the crops and processing equipment, and subsequently job opportunities will be created. The nutritive value of commercial bread will also be enhanced by the addition of cowpea flour.
FOOD APPLICATIONS OF A RICE BRAN OIL STRUCTURED LIPID IN FRIED SWEET POTATO CHIPS AND AN ENERGY BAR
Authors: JENNINGS BRENDA H. , SHEWFELT ROBERT L. , AKOH CASIMIR C.
Published: December 2010

A rice bran oil structured lipid (RBOSL) was synthesized from rice bran oil (RBO) and caprylic acid with Lipozyme RM IM as biocatalyst. Sweet potato chips (SPCs) were fried separately in RBOSL and RBO. Energy bars (EBs) were formulated with RBOSL or RBO. Triangle tests (TT) were conducted for SPCs and EBs to determine the panelists' ability to differentiate between SPCs and EBs prepared with RBO or RBOSL. Willingness to purchase (WTP) sensory analysis was also conducted. Fatty acid content, γ‐oryzanol, viscosity, free fatty acid (FFA) and p‐anisidine values for RBO and RBOSL were determined before and after frying. SPC color and oil uptake were also determined. TT results for SPCs showed no significant difference in SPCs fried in RBO and RBOSL (P > 0.05). TT results for EBs indicated a significant difference between RBO and RBOSL formulations (P ≤ 0.05). WTP (5‐point scale) sensory analyses of SPCs and EBs showed that the most frequent response was probably would buy.

PRACTICAL APPLICATIONS

Consumer panels indicated a willingness to purchase both sweet potato chips and energy bars prepared with rice bran oil structured lipid (RBOSL). Improvements in the standardization and preparation procedures and changes in formulation would probably improve acceptability. These consumer panel results showed that products prepared with structured lipids, with improved nutritional or health‐promoting properties, may have viable commercial potential in foods. RBOSL that is liquid at room temperature can potentially be used in frying and baking applications.
Autoimmune disease as a risk factor for globus pharyngeus: a cross‐sectional epidemiological study
Authors: Masterson L.M. , Srouji I.A. , Musonda P. , Scott D.G.I.
Published: December 2010

Clin. Otolaryngol. 2011, 36, 24–29

Objective:  To assess the prevalence and severity of globus‐type symptoms in individuals who have a prior diagnosis of autoimmune disease.

Design:  Cross‐sectional questionnaire.

Participants and setting:  One hundred and nine patients with autoimmune disease (rheumatoid arthritis, seronegative spondarthritis, connective tissue disease, systemic vasculitis) and 41 patients with non‐autoimmune disease (osteoarthritis/osteoporosis) attending a rheumatology tertiary referral clinic at Norfolk & Norwich University Hospitals NHS Foundation Trust. The results from this study were compared to previous published figures in patients with globus pharyngeus (n = 105) and normal population (n = 174).

Main outcome measures:  Glasgow Edinburgh Throat Scale questionnaire; Reflux Symptom Index; Anxiety/Depression Scale.

Results:  Patients with autoimmune disease demonstrate a significantly higher prevalence for 5/10 symptoms on the Glasgow Edinburgh Throat scale score when compared to the non‐autoimmune control group (P ≤ 0.01). This significant difference increases to 9/10 symptoms when compared to published results for the normal population (P = 0.01). No significant difference was found when comparing the autoimmune and non‐autoimmune control group reflux symptom index (P = 0.64) or anxiety depression scale (P = 0.71).

Conclusion:  Patients with autoimmune disease have a significantly increased prevalence of globus symptoms when compared to the healthy population. A further prospective study is required to decipher the effect of pharmacotherapy as a possible causative factor.
Improvements in Insulin Sensitivity and Muscle Blood Flow in Aerobic‐Trained Overweight‐Obese Hypertensive Patients Are Not Associated With Ambulatory Blood Pressure
Authors: Waib Paulo H. , Gonçalves Maria I. , Barrile Silvia R.
Published: December 2010

To verify whether there are relationships between vascular and hormonal responses to aerobic training in hypertensive persons, sedentary hypertensive patients were randomized to an aerobic training or a callisthenic exercise group. The patients’ 24‐hour blood pressure, arterial compliance, forearm blood flow, and hormonal profile were evaluated at baseline and after 3‐month training protocols. Mean maximal oxygen consumption (VO2max) increased by 8% in the aerobic group (P<.001), while no change was observed in the control group. There was a decrease in insulin resistance (homeostatic model assessment of insulin resistance, P=.039) and plasma cortisol (P=.006) in the aerobic group only, that also demonstrated an increase in forearm blood flow (P<.001) after training. No relationship was observed between change in blood pressure or change in body mass and other parameters. Aerobic training can promote a decrease in cardiovascular risk in hypertensive adults by improving vascular function and insulin resistance, despite no changes in ambulatory blood pressure after a 3‐month intervention. J Clin Hypertens (Greenwich). 2011;13:89–96. © 2010 Wiley Periodicals, Inc.
The Sources and Resources of Our Indigenous Theology: An Australian Aboriginal Perspective
Authors: Parkin Evelyn
Published: December 2010

I will attempt to show the Australian Aboriginal Christian from the spiritual, physical and cultural perspectives. The point that I wish to highlight is that there is an expression of continuity of relationship and ritual sacredness between my ancient people and their Higher Power (known by various names). This relationship is an unbroken thread that has weaved its way through the passages of time. It has been passed on for thousands of years to us here today as Aboriginal Christians. We are not only the “Children of God,” but are also the “Children of the Dreaming”– this is my identity.
Government Intervention in OECD Member Countries: Equity at the Expense of Efficiency?
Authors: Lombard Marc
Published: December 2010

This article examines the presumption that equity considerations prevalent in some of the so‐called welfare states of Organisation for Economic Co‐operation and Development (OECD), and associated with substantial government intervention in the economy, come at the expense of economic efficiency. To verify this presumption, the article selects the OECD’s five highest spending countries, in terms of government expenditure as a percentage of gross domestic product, as well as the five lowest spending countries in the OECD’s upper median income group. The performance of eight economic indicators, representative of both equity considerations and economic efficiency, is then evaluated with respect to each group of countries. The article concludes that while high‐spending countries largely outperform low‐spending countries with regard to equity considerations (such as a more equal income distribution, lower child poverty rate and more generous social benefits), evidence of greater economic efficiency by the low‐spending countries is not apparent, with productivity and inflation rates being even between the two groups, and difference in unemployment rates being challenged by the large incidence of part‐time and casual employment in low‐spending countries.
Revisiting the Relationship Between the Macroeconomy and Indigenous Labour Force Status
Authors: Hunter Boyd
Published: December 2010

Almost 20 years ago, an article in Economic Papers by Altman and Daly asked “Do fluctuations in the macroeconomy influence Aboriginal employment status?” This paper revisits this question in view of recent evidence. Indigenous people are more likely than before to be employed in industries similar to that of other Australians, and hence are less insulated from the business cycle. The greater engagement in the Australian economy is not something to be feared as it means that Indigenous employment will eventually respond to sustained macroeconomic growth. Indeed, Indigenous employment in the private sector converged rather quickly to the Australian average over the ten years of buoyant economic conditions between 1996 and 2006. Economic slow‐downs do circumscribe the ability to improve Indigenous employment outcomes, but this simply means that educational and training investments become even more important in ensuring that Indigenous people are in a competitive position once economic growth picks up again.
Efficacy of Oral Famotidine and 2 Omeprazole Formulations for the Control of Intragastric pH in Dogs
Authors: Tolbert K. , Bissett S. , King A. , Davidson G. , Papich M. , Peters E. , Degernes L.
Published: December 2010

Background:Little is known about the efficacy of commonly used acid suppressants on intragastric pH in dogs.

Objective:To compare the effect of oral famotidine, 2 formulations of omeprazole, and placebo on intragastric pH in dogs with a catheter‐free, continuous pH monitoring system.

Animals:Six healthy adult mixed‐breed colony dogs.

Methods:Utilizing a randomized, 4‐way cross over, open‐label study, dogs were administered famotidine PO (1.0–1.3 mg/kg q12h), omeprazole tablet (1.5–2.6 mg/kg q24h), omeprazole reformulated paste (RP) (Gastrogard, 1.5–2.6 mg/kg q24h), and placebo for 7 days followed by a 10‐day washout period. Radiotelemetric pH capsules were placed with gastroscopy assistance to continuously record intragastric pH for 4 days (days 4–7 of dosing). The percentage of time that intragastric pH was ≥3 and ≥4 was compared among treatment groups using repeated measures of analysis of variance. Tukey's Studentized range test was used to determine which groups were different with α= 0.05.

Results:Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 22 ± 8% and 14 ± 6% for famotidine, 63 ± 14% and 52 ± 17% for omeprazole tablet, 54 ± 17% and 44 ± 18% for omeprazole RP, and 6 ± 6% and 5 ± 5% for placebo. Both omeprazole formulations significantly increased intragastric pH compared with famotidine and placebo, but omeprazole tablet and RP was not significantly different from each other.

Conclusion:Oral omeprazole tablet and RP provide superior gastric acid suppression to famotidine, and should therefore be considered more effective for the treatment of acid related disorders in dogs.
Simulation Comparison of PEMFC Micro-Cogeneration Units With Conventional and Innovative Fuel Processing
Authors: Roses Leonardo , Bonalumi Davide , Campanari Stefano , Iora Paolo , Manzolini Giampaolo
Published: December 2010

This paper deals with the performance comparison over simulated micro-cogeneration units based on polymer electrolyte membrane fuel cells (PEMFC or PEM), when the fuel is processed by means of two contrasting techniques. On the one hand with the use of conventional natural gas steam reforming (SR), and on the other, the adoption of an innovative palladium based membrane-reformer. After the definition of the plant layout, which reflects the results of previous studies and includes all the components of a 4 kW PEM for combined heat and power production, the comparison among the plant performances is carried out with two approaches: (i) using a in-house developed code (GS), able to calculate mass and energy balances, as well as a number of specific component parameters, already applied to a large variety of plant simulations, and (ii) using a commercial code (Aspen Plus®). The comparison allows to validate the simulated performance results as well as to evidence the advantages of the two approaches and to assess the effects of different simulation assumptions.
Predicting Through-Plane Water Distribution in a Polymer Electrolyte Fuel Cell
Authors: Wang Yun , Chen Ken S.
Published: December 2010

In this paper, a two-dimensional (2D) model is presented for simulating the coupled phenomena of gaseous fuel/reactant flows, species (including liquid water) transport, heat transfer, hydrogen oxidation and oxygen reduction reactions in a PEM fuel cell. A 1D analysis is presented to explain the characteristics of water-content profile at the cathode GDL (gas diffusion layer)-MPL (microporous layer) interface and possible reasons for no experimental observation on the characteristics. 2D model predictions are further computed numerically and compared with available experimental data from neutron imaging. Reasonably good agreements are obtained in comparisons between the computed water profiles and the neutron-imaging data. Case-study simulations are carried out for PEM fuel cell operation at various current densities and 40 °C. The results show that the cathode water content increases with the current density, but the anode side exhibits a complex trend at the considered temperature operation: at high current density the anode water content may become lower partly due to the local heating.
Advanced Model of Solid Oxide Fuel Cell
Authors: Milewski Jaroslaw
Published: December 2010

The advanced mathematical model of Solid Oxide Fuel Cell (SOFC) is presented. Electrochemical, thermal, electrical and flow parameters are collected in the 0D mathematical model. The aim was to combine all cell working conditions in as low number factors as possible (maximum voltage, maximum current density, internal ionic resistance, internal electrical resistance, and fuel utilization factor), which can be relatively easy to determine. A validation process for experimental data was made and adequate results are shown.
3-D Volume of Fluid Model for Proton Exchange Membrane Fuel Cells With Phase Change Effects
Authors: Le Anh Dinh , Zhou Biao
Published: December 2010

In this study, a 3-D Volume of Fluid (VOF) model has been developed to simulate the liquid water formation and transport with phase-change effects in real-time operation of a Proton Exchange Membrane Fuel Cell (PEMFC). By applying mass-transfer process incorporated with interface tracking algorithm of VOF method, this model provides the numerical visualization of formation, deformation, and removal processes of liquid water in the channels and porous media of PEMFC. The simulation results indicate that liquid water can be formed in certain regions in both the channel and porous media. The water amounts due to condensation/evaporation are quantitatively determined by the phase change rate among other factors. This approach and its results show that a real-time operation of a PEMFC can be numerically simulated along with experimental visualization.
Steady-State Modeling of Methane Fueled SOFC-GT System: Variation of Operational Parameters Throughout the Cycle
Authors: Zabihian Farshid , Fung Alan S. , Koksal Murat
Published: December 2010

This paper presents results of a steady-state thermodynamic model of a hybrid tubular solid oxide fuel cell (SOFC)-gas turbine (GT) cycle developed using commercial process simulation software, Aspen Plus®. The methane fueled hybrid cycle incorporates a 0-dimensional macro level SOFC model considering three chemical reactions: reaction of H2 with O2 producing H2O, methane steam-reforming reaction, and CO shift reaction. In this paper, all important thermodynamic properties, such as temperature, pressure, mass, volume and molar flow rates, and composition of all major streams in the cycle are investigated for two configurations: cycle with and without anode recirculation. In addition, operational conditions, like power output, specific work, efficiency, and heat duty of all equipments, such as SOFC stack, GT, fuel reformer, compressors, heat exchangers, and pump are evaluated. This work can help in better understanding of hybrid SOFC-GT cycle inner working.
Effect of the Structure Design on the Performance of a Passive Vapor-Feed DMFC Fed With Concentrated Methanol
Authors: Xu Chao , Faghri Amir , Li Xianglin
Published: December 2010

A passive vapor-feed direct methanol fuel cell (DMFC), which has a membrane vaporizer and a hydrophobic vapor transport layer (VTL), was investigated experimentally to improve its performance when fed with highly concentrated or neat methanol. DMFCs with different structure parameters, such as the VTL thickness, open area ratio of the vaporizer, and thickness of the water management layer, were tested using different methanol concentrations varying from 6 M to neat methanol. The results showed that the performance of the passive vapor-feed DMFC mainly depended on the trade-off between the methanol vapor supply to the anode and methanol crossover through the membrane. Thickening the VTL, or decreasing the open area ratio of the vaporizer, were found to effectively decrease the transport rate of methanol vapor to the anode, leading to an increase in the concentration of the optimum methanol feeding. The hydrophobic water management layer in the cathode was also found to be useful to lower the methanol crossover.
Predicted Liquid Water Saturation in Unstructured Pore Networks Based on PEMFC GDL Porosity Profiles
Authors: Hinebaugh J. , Fishman Z. , Bazylak A.
Published: December 2010

An unstructured, two-dimensional pore network model is employed to describe the effect of through-plane porosity profiles on liquid water saturation within the gas diffusion layer (GDL) of the polymer electrolyte membrane fuel cell. Random fibre placements are based on the porosity profiles of six commercially available GDL materials recently obtained through x-ray computed tomography experiments. The pore space is characterized with a Voronoi diagram, and invasion percolation-based simulations are performed. It is shown that water tends to accumulate in regions of relatively high porosity due to the lower associated capillary pressures. It is predicted that GDLs tailored to have smooth porosity profiles will have fewer pockets of high saturation levels within the bulk of the material.
Tolerance Tests of Co-Feeding Cl2 and H2S Impurities in Biogas on a Ni-YSZ Anode-Supported Solid Oxide Fuel Cell
Authors: Xu Chunchuan , Zondlo John W. , Gong Mingyang , Liu Xingbo , Celik I. B.
Published: December 2010

Biogas is a renewable resource which comes from numerous sources, such as biomass, manure, sewage, municipal waste, green waste and energy crops. It is a variable mixture of CH4, CO2, N2 and other gases. Ni-YSZ cermet is commonly used as the anode of a solid oxide fuel cell (SOFC) because it has excellent electrochemical performance and is cost effective. It can utilize not only hydrogen fuel, but also a clean synthesized biogas mixture of varying CH4 and CO2 concentrations with steam (H2O) and air (O2). However, trace impurities, such as H2S, Cl2, and F2 in biogas may cause degradation of cell performance. In this work, Ni-CeO2 coated Ni-YSZ anode-supported cells were exposed to two different compositions of synthesized biogases (biogas) with 100 ppm Cl2 under a constant current load at 850°C. The electrochemical performance was evaluated periodically using standard electrochemical methods. 20 ppm H2S impurity was also added to the fuel stream during the Cl2 impurity testing and its effect was noted. Post-mortem analyses of the SOFC anode were performed using XRD, SEM and XPS. The results show that Cl2 did not cause any electrochemical degradation of the cell during the 200 h test. However, after adding 20 ppm H2S, the cell started to degrade and eventually lost all its performance. The experimental data showed that 100 ppm Cl2 impurity in the fuel gas can postpone the degradation caused by addition of the H2S impurity.
Liquid Water and Gas Flow Simulation in a Channel of PEM Fuel Cells Using the Lattice Boltzmann Method
Authors: Yasser Ben Salah , Tabe Yutaka , Chikahisa Takemi
Published: December 2010

In a polymer electrolyte membrane (PEM) fuel cell, the condensed water in the gas channel prevents the supply of reactants to electrodes, which deteriorates the cell performance. The Lattice Boltzmann simulation has been conducted to understand the behavior of condensed water in the gas channels. The scheme of the two-phase flow with large density difference was applied to find the optimum gas channel design. The present simulation demonstrates the effect of the cross-sectional shape, the droplet initial position, droplet volume and the air flow velocity for a hydrophobic gas channel. Introducing a new dimensionless parameter, which is the pump work needed to remove the droplet from the gas channel, we investigate the effect of each parameter on the drain performance of a PEM fuel cell’s gas channel.
Performance Analysis of Butane Direct Internal Reforming SOFC at Intermediate Temperature
Authors: Yoon Byoung Young , Park Kwangjin , Bae Gyujong , Bae Joongmyeon
Published: December 2010

In this work, the performance of solid oxide fuel cells at an intermediate temperature (600°C) that uses reformate gas and butane as fuel sources is investigated. Anode materials consisting of Ni and Ce0.9Gd0.1O2 (CGO91) and Ni and Y0.08Zr0.92O2 (8YSZ) are tested as steam reforming catalysts. Anode materials using NiO/CGO91 steam to carbon ratio of 3 and butane as the fuel source result in the better performance. However, even if the gas hourly space velocity is very low and NiO/CGO91 is used as the anode, the conversion of butane is not 100%. Additives are added to the NiO/CGO91 materials to increase the conversion of butane. Among the additives tested, the Rh is the most effective, resulting in 100% of butane conversion and no carbon deposition. Moreover, Rh added NiO/CGO91 SOFC single cell have a very low degradation rate when butane is directly used in conditions of steam to carbon ratio 3.
Through-Plane Thermal Conductivity of PEMFC Porous Transport Layers
Authors: Burheim Odne S. , Pharoah Jon G. , Lampert Hannah , Vie Preben J. S. , Kjelstrup Signe
Published: December 2010

We report the through-plane thermal conductivities of the several widely used carbon porous transport layers (PTLs or GDLs) and their thermal contact resistance to an aluminium polarisation plate. We report these values both for wet and dry samples and at different compaction pressures. We show that depending on the type of PTL and possible residual water, the thermal conductivity of the materials varies from 0.15 to 1.6 W K−1 m−1 — one order of magnitude. This behaviour is the same for the contact resistance varying from 0.8 to 11 10−4 m2 K W−1. For dry PTLs the thermal conductivity decreases with increasing PTFE content and increases with residual water. These effects are explained by the behaviour of air, water and PTFE in between the PTL fibres.
Model-Based System Design of Highly-Efficient Integrated Gasification Fuel Cell Power Plants
Authors: Kameswaran Shivakumar , Xi Handa , Junker S. Tobias , Peles Slaven , Yamanis Jean , Sun Ellen
Published: December 2010

The present study focuses on the model-based conceptual design of utility-scale power generation systems with a power block comprising a Solid Oxide Fuel Cell (SOFC) and steam/gas turbine bottoming cycles. The design includes production of coal gas via coal gasification, coal gas clean-up process steps, as well as carbon capture technology downstream of the power block. Various options for system design configurations and operating parameters exist for such power plants. The current work focuses on a subset of these configurations that makes use of catalytic coal gasification, state-of-the-art gas turbine technology, and oxy-combustion for straightforward carbon separation. A library of first-principles component models for gasifier, SOFC, gas and steam turbines, and oxygen combustor as well as phenomenological models for the air separation unit and coal gas clean-up process were developed. System analyses of two atmospheric and a pressurized system concept will be presented. The three system configurations will be compared using system performance metrics. All systems meet the Solid State Energy Conversion Alliance (SECA) minimum requirements, i.e., produce ≥100 MW power with ≥50% electrical efficiency based on coal HHV and capture more than 90% of the carbon in the coal feedstock.
Modeling of Microfluidic Fuel Cells With Flow-Through Porous Electrodes
Authors: Khabbazi Ali Ebrahimi , Hoorfar Mina
Published: December 2010

This paper presents a modeling of a microfluidic fuel cell with flow-through porous electrodes using vanadium redox couples as the fuel and oxidant. There are advantages associated with the use of vanadium redox species in microfluidic fuel cell: 1) vanadium redox couples have the possibility of producing high open-circuit potential (up to 1.7 V at uniform PH [1]); 2) they have high solubility (up to 5.4 M) which causes more species available to the electrodes; 3) they do not require metal catalyst for electrochemical reactions so the reactions take place on the bare carbon electrodes. This characteristic of the vanadium redox couple make them a great candidate as reactants as they do not need expensive catalyst coatings on the electrodes. The fuel and the oxidant can be brought into contact with the electrode in two different ways: flowing over the electrodes or flowing through the electrodes. In the presented fuel cell design, the vanadium redox species are forced to flow through the porous electrodes. They finally come to meet each other in the middle microchannel and establish a side-by-side co-laminar flow traveling down the channel. In this paper, the effect of the inlet velocity and electrode porosity has been investigated. As it is expected, the higher velocity results in the higher power densities. For the porosity, however, there is an optimum value. In essence, there is a trade-off between the available electrode surface area and electric conductivity of the solid phase (i.e., the porous carbon electrode). The modeling shows that a porous electrode with a 67% porosity results in the highest power output.
Quantitative Evaluation of Liquid Water at Cathode Interface of Polymer Electrolyte Fuel Cell Using Near-Infrared Reflectance Spectroscopy
Authors: Nishida Kosuke , Ishii Motoyuki , Taniguchi Ryo , Tsushima Shohji , Hirai Shuichiro
Published: December 2010

Water management in cathode electrode of polymer electrolyte fuel cells (PEFCs) is essential for achieving high performance operation, because excessive liquid water accumulated in cathode catalyst layer (CL) and gas diffusion layer (GDL) blocks oxygen transport to active reaction sites. In this study, the liquid water accumulated at the CL|GDL interface of a PEFC was quantitatively evaluated by using near-infrared reflectance spectroscopy (NIRS), and the effects of operating conditions and GDL properties on the liquid water transport in the cathode electrode were investigated. NIRS is a non-invasive optical measurement technique for quantitatively estimating the amount and concentration of water. In this experiment, the thickness of liquid water film at the cathode CL|GDL interface of the fuel cell can be determined by detecting the water absorbance of the NIR light reflected from the CL surface. It was found that the cell voltage drops down to zero when the thickness of liquid film at the cathode CL|GDL interface reaches more than 30 μm. Furthermore, the liquid water accumulation at the cathode CL|GDL interface is affected by hydrophobic treatment of GDL and compression pressure of assembled fuel cell. When the PTFE content inside the cathode GDL increases from 5 to 15 wt%, the amount of liquid water at the cathode CL|GDL interface increases, because the highly hydrophobic treatment of GDL suppresses the liquid water influx into the cathode GDL. The thickness of liquid water film at the CL|GDL interface decreases remarkably with an increase in compression pressure of the assembled cell. The addition of microporous layer (MPL) at the cathode is effective in decreasing the liquid water accumulation at the CL|GDL interface and preventing water flooding.