bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergency Medicine Residents Do Not Document Detailed Neurologic Examinations
Authors: Sarko John
Published: December 2009

Objectives:  Physical examinations performed by residents in many specialties are often incomplete and inaccurate. This report assessed the documentation of the neurologic examination performed by emergency medicine (EM) residents when examining patients with potential psychiatric or neurologic chief complaints.

Methods:  A retrospective chart review of neurologic examinations documented by EM residents was performed. An eight‐item neurologic examination score was created and analyzed by resident postgraduate year. A linear mixed model was used to determine if differences in neurologic examination scores existed between resident year, type of complaint, and resident year and type of complaint. A one‐point difference in scores was considered clinically important.

Results:  A total of 384 charts were reviewed. An average of 4.26 items (95% confidence interval [CI] = 3.91 to 4.62) out of a possible eight were documented that did not vary by resident year of training (p = 0.08). An effect was found for type of complaint. Documentation was lower for psychiatric than for neurologic complaints: mean score for psychiatric complaints 3.97 vs. mean score for neurologic complaints 4.55 (difference –0.58, 95% CI = –1.02 to –0.14). No interaction was found for type of complaint and resident year. A clustering effect was identified for individual residents.

Conclusions:  Emergency medicine residents do not document detailed neurologic examinations on patients with neurologic or psychiatric complaints. Individual resident variation contributes to this documentation.
Serious Bacterial Infection in Recently Immunized Young Febrile Infants
Authors: Wolff Margaret , Bachur Richard
Published: December 2009

Objective:  The objective of this study was to investigate the prevalence of serious bacterial infection (SBI) in febrile infants without a source aged 6–12 weeks who have received immunizations in the preceding 72 hours.

Methods:  The authors conducted a medical record review of infants aged 6–12 weeks with a fever of ≥38.0°C presenting to the pediatric emergency department (ED) over 88 months. Infants were classified either as having received immunizations within the 72 hours preceding the ED visit (recent immunization [RI]) or as not having received immunizations during this time period (no recent immunization [NRI]). Primary outcome of an SBI was based on culture results; only patients with a minimum of blood and urine cultures were studied.

Results:  A total of 1,978 febrile infants were studied, of whom 213 (10.8%) had received RIs. The overall prevalence of definite SBI was 6.6% (95% confidence interval [CI] = 5.5 to 7.7). The prevalence of definite SBI in NRI infants was 7.0% (95% CI = 5.9 to 8.3) compared to 2.8% (95% CI = 0.6 to 5.1) in the RI infants. The prevalence of definite SBI in febrile infants vaccinated in the preceding 24 hours decreased to 0.6% (95% CI = 0 to 1.9). The prevalence of definite SBI in febrile infants vaccinated greater than 24 hours prior to presentation was 8.9% (95 CI = 1.5 to 16.4). The relative risk of SBI with RI was 0.41 (95% CI = 0.19 to 0.90). All SBIs in the RI infants were urinary tract infections (UTI).

Conclusions:  Among febrile infants, the prevalence of SBI is less in the initial 24 hours following immunizations. However, there is still a substantial risk of UTI. Therefore, urine testing should be considered in febrile infants who present within 24 hours of immunization. Infants who present greater than 24 hours after immunizations with fever should be managed similarly to infants without RIs.
Modafinil and Zolpidem Use by Emergency Medicine Residents
Authors: McBeth Brian D. , McNamara Robert M. , Ankel Felix K. , Mason Emily J. , Ling Louis J. , Flottemesch Thomas J. , Asplin Brent R.
Published: December 2009

Objectives:  The objective was to assess the prevalence and patterns of modafinil and zolpidem use among emergency medicine (EM) residents and describe side effects resulting from use.

Methods:  A voluntary, anonymous survey was distributed in February 2006 to EM residents nationally in the context of the national American Board of Emergency Medicine in‐training examination. Data regarding frequency and timing of modafinil and zolpidem use were collected, as well as demographic information, reasons for use, side effects, and perceived dependence.

Results:  A total of 133 of 134 residency programs distributed the surveys (99%). The response rate was 56% of the total number of EM residents who took the in‐training examination (2,397/4,281). Past modafinil use was reported by 2.4% (57/2,372) of EM residents, with 66.7% (38/57) of those using modafinil having initiated their use during residency. Past zolpidem use was reported by 21.8% (516/2,367) of EM residents, with 15.3% (362/2,367) reporting use in the past year and 9.3% (221/2,367) in the past month. A total of 324 of 516 (62.8%) of zolpidem users initiated use during residency. Side effects were commonly reported by modafinil users (31.0%)—most frequent were palpitations, insomnia, agitation, and restlessness. Zolpidem users reported side effects (22.6%) including drowsiness, dizziness, headache, hallucinations, depression/mood lability, and amnesia.

Conclusions:  Zolpidem use is common among EM residents, with most users initiating use during residency. Modafinil use is relatively uncommon, although most residents using have also initiated use during residency. Side effects are commonly reported for both of these agents, and long‐term safety remains unclear.
Off‐service Resident Education in the Emergency Department: Outline of a National Standardized Curriculum
Authors: Kessler Chad S. , Marcolini Evie G. , Schmitz Gillian , Gerardo Charles J. , Burns Glenn , DelliGatti Brian , Marco Catherine A. , Manthey David E. , Gutman Deborah , Jobe Kathleen , Younggren Bradley N. , Stettner Ted , Sokolove Peter E.
Published: December 2009

Although many residency programs mandate at least one rotation in emergency medicine (EM), to the best of our knowledge, a standardized curriculum for emergency department (ED) rotations for “off‐service” residents has not been developed. As a result, the experiences of these residents in the ED tend to vary during their rotations. To design an off‐service EM curriculum, we adopted Kern’s six‐step approach to curriculum development as a conceptual framework. The resulting program encompasses clinical experience and didactic sessions through which residents are trained in core topics and skills. This knowledge will be applicable in the clinical settings in which residents will continue to train and ultimately practice their specialty. It is flexible enough to be applicable and implementable without being limited by resource availability or faculty strengths.
Treatment of class III multiple gingival recessions: a randomized‐clinical trial
Authors: Aroca Sofia , Keglevich Tibor , Nikolidakis Dimitris , Gera Istvan , Nagy Katalin , Azzi Robert , Etienne Daniel
Published: December 2009

Background: The aim of this controlled randomized split‐mouth study was to evaluate whether a modified tunnel/connective tissue graft (CTG) technique – enamel matrix derivative (EMD) combination will improve the treatment of multiple class III recession when compared with the same technique alone.

Materials and Methods: Twenty healthy subjects with a mean age of 31.7 years, were enrolled for the trial in a university periodontal clinic. Patients with at least three adjacent gingival recessions on both sides of the mouth were treated with a modified tunnel/CTG technique. On the test side, an EMD was used in addition. Clinical parameters were measured at baseline, 28 days, 3, 6 and 12 months after the surgery. Results are presented at the subject level.

Results: The mean root coverage from baseline to 1 year post‐surgery was 82% for the test group and 83% for the control group. Complete root coverage was achieved at 1 year in eight (38%) of the 20 surgeries (experimental and control group).

Conclusions: One‐year results indicate that the modified tunnel/CTG technique is predictable for the treatment of multiple class III recession‐type defects. The addition of EMD does not enhance the mean clinical outcomes.
Effects of metals on skin permeability barrier recovery
Authors: Denda Mitsuhiro , Kumazawa Noriyuki
Published: December 2009

Please cite this paper as: Effects of metals on skin permeability barrier recovery. Experimental Dermatology 2010; 19: e124–e127.

Abstract:  We previously demonstrated that the electrical state of the skin surface influences epidermal permeability barrier homeostasis. At the interface between different materials, electrons are localized heterogeneously and induce electrical potential. In the present study, we evaluated the effects of metals on the barrier recovery. When we put pure gold plate on skin immediately after tape stripping, the barrier recovery rate was faster than the control. The acceleration of barrier recovery was blocked when the plate was earthed (grounded). When a plastic membrane was sandwiched between the plate and the skin, the recovery was delayed in comparison with the control. We then used a germanium diode to regulate the current flow between the plate and the earth. When the current was blocked, the barrier recovery was accelerated, but when the current was not blocked, the recovery was not accelerated. These results suggest that localization of electron might affect for the barrier recovery rate. The level of interfacial electric potential would be different due to the electrochemical property of metal. Thus, we next evaluated the effects of other metals. With samarium, zirconium, iridium and silver, the barrier recovery rate was faster than in the case of gold, while a platinum plate induced slower recovery than in the case of gold. There was a significant correlation between work function of each metal and barrier recovery rate. These results suggest that electron donation from outside accelerated the skin barrier recovery.
The Role of Trust in Low‐Income Mothers' Intimate Unions
Authors: Burton Linda M. , Cherlin Andrew , Winn Donna‐Marie , Estacion Angela , Holder‐Taylor Clara
Published: December 2009

Recent scholarship concerning low rates of marriage among low‐income mothers emphasizes generalized gender distrust as a major impediment in forming sustainable intimate unions. Guided by symbolic interaction theory and longitudinal ethnographic data on 256 low‐income mothers from the Three‐City Study, we argue that generalized gender distrust may not be as influential in shaping mothers' unions as some researchers suggest. Grounded theory analysis revealed that 96% of the mothers voiced a general distrust of men, yet that distrust did not deter them from involvement in intimate unions. Rather, the pivotal ways mothers enacted trust in their partners were demonstrated by 4 emergent forms of interpersonal trust that we labeled as suspended, compartmentalized, misplaced, and integrated. Implications for future research are discussed.
Women's “Justification” of Domestic Violence in Egypt
Authors: Yount Kathryn M. , Li Li
Published: December 2009

We explored the influences of women's social learning, marital resources and constraints, and exposure to norms about women's family roles on their views about wife hitting or beating among 5,450 participants in the 2005 Egypt Demographic and Health Survey. One half justified wife hitting or beating for some reason. Women from rural areas who were exposed to domestic violence more often justified such acts. Dependent wives whose husbands had more schooling, were blood relatives, and were coresident more often justified such acts. In settings where women tended to marry at older ages, women less often justified such acts. Women's resources and constraints in marriage accounted for the largest share of the variability in their attitudes about domestic violence against women.
Parental Work Demands and the Frequency of Child‐Related Routine and Interactive Activities
Authors: Roeters Anne , Van Der Lippe Tanja , Kluwer Esther S.
Published: December 2009

This study examined whether the frequency of child‐related activities was associated with parents' own work demands and those of their partners. In addition to parental paid working hours, we considered the parents' organizational culture and experienced job insecurity. Moreover, we differentiated between child‐related routine and interactive activities. Using self‐collected data on 639 Dutch couples with children, we found that paid working hours were consistently associated with a lower frequency of child‐related activities. Fathers generally responded more strongly to their own and their partner's work demands than mothers. For fathers, both their own and their partner's work demands were more strongly associated with routine than with interactive activities. Mothers did not differentiate between these activities, however.
The Rise of Age Homogamy in 19th Century Western Europe
Authors: Van de Putte Bart , Van Poppel Frans , Vanassche Sofie , Sanchez Maria , Jidkova Svetlana , Eeckhaut Mieke , Oris Michel , Matthijs Koen
Published: December 2009

In many parts of Western Europe the age at first marriage and the level of celibacy declined in the second half of the 19th century. This weakening of the European marriage pattern (EMP) can be interpreted as a “classic” response to the increase of the standard of living, but a more far‐reaching interpretation is that the erosion of the EMP was part of a cultural shift characterized by the rise of a new, less instrumental and more egalitarian view on marriage and partner selection. The latter vision implies the increase of the preference for a same age marriage. We test this explanation by using a combined Belgian‐Dutch data set of marriage certificates (N = 766,412). Our findings corroborate the “cultural shift thesis.”
The Long‐Term Consequences of Relationship Formation for Subjective Well‐Being
Authors: Soons Judith P. M. , Liefbroer Aart C. , Kalmijn Matthijs
Published: December 2009

This study examines how relationship transitions affect subjective well‐being (SWB) and how this effect changes over time. We used prospective data containing information about 18 years of young adults' lives (PSIN, N = 5, 514). SWB was measured with the Satisfaction with Life Scale. Within‐person multilevel regression analyses showed that dating, unmarried cohabitation, and marriage had additional well‐being enhancing effects. After entry into a union, well‐being slowly decreased. A large SWB decrease was found after union dissolution, but through adaptation or repartnering well‐being increased again. Well‐being of never‐married and never‐cohabiting young adults decreased slowly over time. These effects were independent of parenthood and employment. Our results confirm expectations from the resources theory but contradict some assumptions of the set‐point theory.
Associations of Childhood Religious Attendance, Family Structure, and Nonmarital Fertility Across Cohorts
Authors: Wildeman Christopher , Percheski Christine
Published: December 2009

This article considers associations among childhood family structure, childhood religious service attendance, and the probability of having a nonmarital first birth before age 30 for non‐Hispanic White women born 1944 to 1964 using data from the 1988 and 1995 waves of the National Survey of Family Growth (N = 5,995). We found that attending religious services weekly during childhood and growing up in a 2‐biological‐parent family were associated with lower odds of having had a nonmarital first birth. These associations were quite stable across cohorts, although religious attendance was less associated with nonmarital fertility for the youngest cohort. We estimate that changes in these childhood experiences account for 22% of the increase in nonmarital first births across these cohorts.
The Effects of Experimentally-Induced Sad and Happy Mood on Sexual Arousal in Sexually Healthy Women
Authors: Ter Kuile Moniek M. , Both Stephanie , Van Uden Janneke
Published: December 2009

Introduction

In depressed women, common sexual difficulties include decreased sexual desire, sexual arousal and orgasmic difficulties, reduced sexual satisfaction, and reduced sexual pleasure. Experimental research on the influence of depressed mood on genital and subjective sexual arousal in women is scarce.

Aim

To investigate the effects of sad mood on genital and subjective sexual arousal in sexually healthy women, using a mood induction procedure.

Method

Thirty-two subjects received a sad mood and a happy mood induction, on two different days, using a within subjects design. The mood induction procedure was a combination of the Velten procedure and music. In the Velten procedure, the subject is asked to read sad or happy self-referent sentences and to experience the mood suggested by these sentences. Immediately following mood induction, the subjects were exposed to an erotic film clip.

Main Outcome Measure

Genital arousal was assessed using vaginal photoplethysmography. Self-report ratings of sad and happy mood, subjective sexual arousal and affective reactions were collected before and after the erotic clip.

Results

The sad and happy mood ratings indicated that the mood inductions affected mood as intended. No difference in genital sexual arousal was found between the sad and happy mood conditions. Subjects reported significantly less subjective sexual arousal and positive affect and marginally significant fewer genital sensations and more negative affect in the sad mood condition than in the happy mood condition.

Conclusions

The results provide empirical support for the idea that mood can impact on subjective sexual arousal in women.
Original Research—Surgery: Sexual Function after Loop Electrosurgical Excision Procedure for Cervical Dysplasia
Authors: Inna Namfon , Phianmongkhol Yupin , Charoenkwan Kittipat
Published: December 2009

Introduction

Loop electrosurgical excision procedure (LEEP) is an effective tool for management of cervical dysplasia. However, removal of a part of the cervix might have a negative impact on sexual function.

Aim

To examine the effect of LEEP on overall sexual satisfaction and other specific aspects of sexual function in women with cervical dysplasia.

Methods

Eighty-nine premenopausal women with cervical dysplasia who had undergone LEEP at least 3 months previously were interviewed once on post-LEEP follow-up visits with a questionnaire on pre- and post-procedural sexual function. Data on frequency of sexual intercourse, the presence of dysmenorrhea, dyspareunia, and postcoital bleeding were compared using the McNemar test. Data on specific aspects of sexual function rated by the 6-point Likert scale were analyzed using Wilcoxon signed ranks test.

Main Outcome Measure

The main outcome is the overall sexual intercourse satisfaction.

Results

The mean age was 41.7 years. The median interval from LEEP to the time of interview was 29.3 weeks. The time of resumption of sexual intercourse after LEEP was 8.1 weeks on the average. The changes in the frequency of sexual intercourse, dysmenorrhea, and dyspareunia after LEEP were not statistically significant. The changes in overall satisfaction, vaginal elasticity, and orgasmic satisfaction appeared statistically significant (P <0.05).

Conclusion

Having LEEP done along with other “non-surgical” parts of cervical pre-cancer management is associated with small but statistically significant decreases in overall sexual satisfaction, vaginal elasticity, and orgasmic satisfaction when interviewed near to the procedure at 29.3 weeks post-operation. However, the changes on other aspects of sexual function are insignificant. The LEEP procedure itself appears to have a minimal, if any, clinically important adverse effect on sexual function.
Sexual Dysfunction in an Internet Sample of U.S. Men Who Have Sex with Men
Authors: Hirshfield Sabina , Chiasson Mary Ann , Wagmiller Robert L. , Remien Robert H. , Humberstone Mike , Scheinmann Roberta , Grov Christian
Published: December 2009

Introduction

Relatively little is known about sexual dysfunction (SD) in men who have sex with men (MSM).

Aim

In order to better understand SD symptoms in MSM, we assessed self-reported SD symptoms, individually and by latent class analysis (LCA).

Methods

In 2004–2005 an Internet sample of U.S. MSM was recruited from gay-oriented sexual networking, chat and news websites. The analytic sample comprised 7,001 men aged 18 or older who reported lifetime male sex partners and oral or anal sex with a male partner in their most recent encounter within the past year.

Main Outcome Measures

Seven questions on SD symptoms that occurred during the past 12 months inquired about low sexual desire, erection problems, inability to achieve an orgasm, performance anxiety, premature ejaculation, pain during sex, and sex not being pleasurable.

Results

Self-reported symptoms of SD were high. Overall, 79% of men reported one or more SD symptoms in the past year, with low sexual desire, erection problems, and performance anxiety being the most prevalent. Four distinct underlying patterns of sexual functioning were identified by LCA: no/low SD, erection problems/performance anxiety, low desire/pleasure, and high SD/sexual pain. High SD/sexual pain was distinguished from the other patterns by club drug use and use of prescription and non-prescription erectile dysfunction medication before sex in the past year. Additionally, men associated with the high SD/sexual pain group were younger, single, more likely to have poor mental and physical health, and more likely to have been diagnosed with a sexually transmitted infection in the past year compared to men in the no/low SD group.

Conclusions

LCA enabled us to identify underlying patterns of sexual functioning among this sample of MSM recruited online. Future research should investigate these distinct subgroups with SD symptoms in order to develop tailored treatments and counseling for SD.
The discovery of a 21-kG magnetic field in the Ap star BD+0°4535
Authors: Elkin V. G. , Kurtz D. W. , Nitschelm C. , Unda-Sanzana E.
Published: December 2009

With high-resolution spectral observations using a 2.2-m telescope, we found that the Ap star BD+0°4535 has a very strong magnetic field. From Zeeman components of rare earth element spectral lines, we detected an average magnetic field modulus of about 21 kG, although for lines of different chemical elements the estimated magnetic field ranges between 15 and 23 kG. This is a consequence of non-uniform surface distribution of these elements. Considering its possible variation with rotation period, the upper limit of magnetic field is potentially larger than what we have detected. For rare earth elements, large overabundances and ionization disequilibria were found.
Marfan syndrome
Authors: Gonzales Elizabeth A.
Published: December 2009

Purpose: To provide an overview of Marfan syndrome (MFS), including diagnostic criteria, genetic factors involved, emerging theories for treatment, a case study, and an overview of genetic counseling for individuals and families of those with MFS.

Data Sources: Selected research, review, and clinical articles.

Conclusions: MFS is a connective tissue disorder with distinct physical characteristics. Recent advances in the field of genetics have traced this disease process to certain gene mutations. Affecting the optical, skeletal and cardiovascular systems, MFS can cause significant morbidity and mortality if left untreated. Close surveillance and early treatment are necessary to ensure a normal life span.

Implications for Practice: It is important for the advanced practice nurse (APN) to be aware of the complications in those with MFS. Attentive surveillance can decrease mortality and morbidity associated with this syndrome. A multidisciplinary approach, utilizing the expertize of the APN, is necessary for comprehensive care.
Risk factors for endoparasitism in dogs: retrospective case–control study of 6578 veterinary teaching hospital cases
Authors: Gates M. C. , Nolan T. J.
Published: December 2009

Objectives:The diagnostic utility of routine faecal examinations can be greatly enhanced through an appreciation of risk factors most commonly associated with endoparasitism.

Methods:From a sample of 6578 canine patients presenting to a veterinary teaching hospital between 1996 and 2006, this study used univariate and multi‐variable techniques to examine putative signalment, medical history and demographic factors predisposing dogs to intestinal parasites.

Results:Age and median household income were the strongest predictors of endoparasitism. The odds of a patient being diagnosed with endoparasites were 0·82 times smaller for every 1 year increase in age (OR=0·82, 95% CI: 0·80 to 0·84) and for every $10,000 increase in median household income, the odds were 0·86 times lower (OR=0·86, 95% CI: 0·83 to 0·89). The variables gender, neuter status, month of diagnosis, admitting clinical service and primary diagnosis were not significant predictors. Animals that were presented for underlying medical conditions were less likely to have parasites and the presence of diarrhoea was associated with 76% lower odds of endoparasitism compared to healthy animals (OR=0·76, 95% CI: 0·64 to 0·90).

ClinicalSignificance:Clinicians should maintain a high index of suspicion for parasites in younger patients that live in high population density and low income neighbourhoods.
Achieving success with small, translocated mammal populations
Authors: Van Houtan Kyle S. , Halley John M. , Van Aarde Rudi , Pimm Stuart L.
Published: December 2009

Translocations are increasingly important tools for endangered species conservation, but their success is often uncertain. We analyzed 125 time series of grazing mammal translocations in South African protected areas. Some 94% of translocations succeeded (66% unambiguously) even though most populations began with <15 individuals and most of the species involved are of conservation concern. Adding new individuals to existing small populations increases per capita growth rates and seems to prevent translocations from failing. Growth of the translocated populations is both greater and less variable than wild mammal populations and appears less affected by the typically important ecological factors (e.g., initial propagule size, precipitation, reserve size, or presence within historical range). One‐third of the populations showed robust signs of density dependence but we detect few examples of Allee effects. Our results, from empirical time series of small populations, offer new insights into achieving success for translocation programs limited to releasing few individuals.
Over‐harvesting driven by consumer demand leads to population decline: big‐leaf mahogany in South America
Authors: Grogan James , Blundell Arthur G. , Landis R. Matthew , Youatt Ani , Gullison Raymond E. , Martinez Martha , Kómetter Roberto , Lentini Marco , Rice Richard E.
Published: December 2009

Consumer demand for the premier neotropical luxury timber, big‐leaf mahogany (Swietenia macrophylla), has driven boom‐and‐bust logging cycles for centuries, depleting local and regional supplies from Mexico to Bolivia. We revise the standard historic range map for mahogany in South America and estimate the extent to which commercial stocks have been depleted using satellite data, expert surveys, and sawmill processing center data from Brazil. We estimate an historic range of 278 million hectares spanning Venezuela to Bolivia, 57% of this in Brazil. Approximately 58 million hectares (21%) of mahogany's historic range had been lost to forest conversion by 2001. Commercial populations had been logged from at least 125 million more hectares, reducing the commercial range to 94 million hectares (34% of historic). Surviving stocks are extremely low‐density populations in remote regions representing a smaller fraction of historic stocks than expected based on estimated current commercial range. Our method could advance international policy debates such as listing proposals for CITES Appendices by clarifying the commercial and conservation status of high‐value timber species similar to mahogany about which little information is available. The fate of remaining mahogany stocks in South America will depend on transforming current forest management practices into sustainable production systems.
A Tale of Two Cities: The Political Economy of Local Investment Climate in Solo and Manado, Indonesia1
Authors: Patunru Arianto A. , McCulloch Neil , Von Luebke Christian
Published: December 2009

There is little doubt that orthodox institutional prescriptions, such as the protection of property rights, low corruption, and effective public services are desirable long‐term objectives for all countries. But it is not clear whether implementing such prescriptions is sufficient, or even necessary, to achieve investment and growth. By taking a deeper look into the political economy of the cities of Solo and Manado in Indonesia, this paper shows that relationship‐based, rather than rule‐based, cooperation between government leaders and local firms can provide an effective mechanism to boost investment and improve local investment climates. In the case of Solo, a ‘heterodox symbiosis’ between public and private actors – involving the mayor and a broad spectrum of multi‐sectoral/scale/ethnic firms – has brought about important regulatory and administrative reforms and contributed to a rise in private investment. On the other hand, Manado's government is characterised by a poorly planned, rent‐seeking bureaucracy. At the same time, exclusive informal relationships between Manado's leaders and a small number of influential businessmen have facilitated a high level of investment and growth. Our study therefore challenges the conventional wisdom that impartial rule‐based economic governance is a precondition for investment, although it suggests that the creation of such institutions may be necessary to sustain growth in the medium term.
Application of Fractional Scaling Analysis to Loss of Coolant Accidents: Component Level Scaling for Peak Clad Temperature
Authors: Catton Ivan , Wulff Wolfgang , Zuber Novak , Rohatgi Upendra
Published: December 2009

Fractional scaling analysis (FSA) is demonstrated here at the component level for depressurization of nuclear reactor primary systems undergoing a large-break loss of coolant accident. This paper is the third of a three-part sequence. The first paper by Zuber et al. (2005, “Application of Fractional Scaling Analysis (FSA) to Loss of Coolant Accidents (LOCA), Part 1. Methodology Development,” Nucl. Eng. Des., 237, pp. 1593–1607) introduces the FSA method; the second by Wulff et al. (2005, “Application of Fractional Scaling Methodology (FSM) to Loss of Coolant Accidents (LOCA), Part 2. System Level Scaling for System Depressurization,” ASME J. Fluid Eng., to be published) demonstrates FSA at the system level. This paper demonstrates that a single experiment or trustworthy computer simulation, when properly scaled, suffices for large break loss of coolant accident (LBOCAs) in the primary system of a pressurized water reactor and of all related test facilities. FSA, when applied at the system, component, and process levels, serves to synthesize the world-wide wealth of results from analyses and experiments into compact form for efficient storage, transfer, and retrieval of information. This is demonstrated at the component level. It is shown that during LBOCAs, the fuel rod stored energy is the dominant agent of change and that FSA can rank processes quantitatively and thereby objectively in the order of their importance. FSA readily identifies scale distortions. FSA is shown to supercede use of the subjectively implemented phenomena identification and ranking table and to minimize the number of experiments, analyses and computational effort by reducing the evaluation of peak clad temperature (PCT) to a single parameter problem, thus, greatly simplifying uncertainty analysis.
Flow Separation Control on a Race Car Wing With Vortex Generators in Ground Effect
Authors: Kuya Yuichi , Takeda Kenji , Zhang Xin , Beeton Scott , Pandaleon Ted
Published: December 2009

Flow separation control using vortex generators on an inverted wing in ground effect is experimentally investigated, and its performance is characterized in terms of forces and pressure distributions over a range of incidence and ride height. Counter-rotating and co-rotating rectangular-vane type vortex generators are tested on the suction surface of the wing. The effect of device height and spacing is investigated. The counter-rotating sub-boundary layer vortex generators and counter-rotating large-scale vortex generators on the wing deliver 23% and 10% improvements in the maximum downforce, respectively, compared with the clean wing, at an incidence of one degree, and delay the onset of the downforce reduction phenomenon. The counter-rotating sub-boundary layer vortex generators exhibit up to 26% improvement in downforce and 10% improvement in aerodynamic efficiency at low ride heights. Chordwise pressure measurement confirms that both counter-rotating vortex generator configurations suppress flow separation, while the co-rotating vortex generators exhibit negligible effectiveness. This work shows that a use of vortex generators, notably of the counter-rotating sub-boundary layer vortex generator type, can be effective at controlling flow separation, with a resultant improvement in downforce for relatively low drag penalty.
An Experimental and Analytical Investigation of Rectangular Synthetic Jets
Authors: Krishnan Gopi , Mohseni Kamran
Published: December 2009

In this paper the flow field of a rectangular synthetic jet driven by a piezoelectric membrane issuing into a quiescent environment is studied. The similarities exhibited by synthetic and continuous turbulent jets lead to the hypothesis that a rectangular synthetic jet within a limited region downstream of the orifice be modeled using similarity analysis just as a continuous planar jet. Accordingly, the jet is modeled using the classic two-dimensional solution to a continuous jet, where the virtual viscosity coefficient of the continuous turbulent jet is replaced with that measured for a synthetic jet. The virtual viscosity of the synthetic jet at a particular axial location is related to the spreading rate and velocity decay rate of the jet. Hot-wire anemometry is used to characterize the flow downstream of the orifice. The flow field of rectangular synthetic jets is thought to consist of four regions as distinguished by the centerline velocity decay. The regions are the developing, the quasi-two-dimensional, the transitional, and the axisymmetric regions. It is in the quasi-two-dimensional region that the planar model applies, and where indeed the jet exhibits self-similar behavior as distinguished by the collapse of the lateral time average velocity profiles when scaled. Furthermore, within this region the spanwise velocity profiles display a saddleback profile that is attributed to the secondary flow generated at the smaller edges of the rectangular orifice. The scaled spreading and decay rates are seen to increase with stroke ratio and be independent of Reynolds number. However, the geometry of the actuator is seen to additionally affect the external characteristics of the jet. The eddy viscosities of the synthetic jets under consideration are shown to be larger than equivalent continuous turbulent jets. This enhanced eddy viscosity is attributed to the additional mixing brought about by the introduction of the periodic vortical structures in synthetic jets and their ensuing break down and transition to turbulence. Further, a semi-empirical modeling approach is proposed, the final objective of which is to obtain a functional relationship between the parameters that describe the external flow field of the synthetic jet and the input operational parameters to the system.
Experimental Measurement of Laminar Axisymmetric Flow Through Confined Annular Geometries With Sudden Inward Expansion
Authors: Goharzadeh Afshin , Rodgers Peter
Published: December 2009

In this paper, separating and reattaching aqueous laminar flows produced by a sudden inward expansion within confined annular geometries are experimentally studied. The test geometries are based on a previous numerical study. The fluid flow structure at the expansion region is experimentally characterized using particle image velocimetry combined with refractive index matching. The detailed measurements of the velocity field, reattachment length, and relative eddy intensity are obtained for two different expansion ratios, 1.4 and 1.6. For both expansion ratios, the reattachment length is found to vary nonlinearly with the Reynolds number (50<Re<600), in line with numerical predictions. The eddy intensity is found to depend strongly on both the Reynolds number and expansion ratio with the relationship between the Reynolds number and the reattachment length being nonlinear. Overall, the corresponding numerical predictions are in good agreement with the measurements undertaken herein.
Image processing using shape recognition for alignment to damaged registration marks in electron beam lithography
Authors: Kratschmer E. , Klaus D. P. , Viswanathan R. , Turnidge M. L. , Reed P. L. , McPhail B.
Published: December 2009

Shape locate mark registration, a novel image processing technique to accurately locate even damaged registration marks, has been used to resolve alignment challenges in aggressively scaled lithography levels for sub-32 nm complementary metal oxide semiconductor devices. The achievable overlay using traditional registration hardware and software is ultimately limited by the quality of the registration marks and any changes in the registration mark signals caused by device process steps between overlay critical exposure levels. This article discusses the details in the shape locate mark registration and results achieved for the device program. The shape locate mark registration system has been implemented and tested on a Vistec VB6 electron beam lithography tool. Mark locate repeatabilities of better than 5 nm (3σ) across 200 mm wafers and better than 10 nm overlay for device lithography have been demonstrated. Highly scaled 22 nm node fin field effect transistor (FinFET) static random access memory cells of area down to 0.099 μm2 were fabricated using all e-beam lithography and shape locate registration to demonstrate the scalability of FinFET technology (Kawasaki et al., Tech. Dig. – Int. Electron. Devices Meet, 2008, p. 237).
Simple technique for beam focusing in electron beam lithography on optically transparent substrates
Authors: Schuette Michael L. , Lu Wu
Published: December 2009

A beam focusing technique is developed for electron beam lithography on transparent substrates wherein the substrate height is estimated as a plane calculated from height data measured from perimeter metal. The effectiveness of this method, which avoids problems associated with metal-on-resist coatings, is verified with pores and gratings in ZEP520A resist on 1×1in.2 indium tin oxide/quartz slides and on 4 in. quartz wafers. Using a Vistec EBPG-5000 electron beam lithography tool at 50 keV, we achieved consistent 18 nm diameter pores at 59 nm pitch across 41 μm of substrate tilt without direct height measurements at the writing sites.
Cold-developed electron-beam-patterned ZEP 7000 for fabrication of 13 nm nickel zone plates
Authors: Reinspach Julia , Lindblom Magnus , von Hofsten Olov , Bertilson Michael , Hertz Hans M. , Holmberg Anders
Published: December 2009

Cold development was applied to improve the resolution in a trilayer resist that is used for the fabrication of state-of-the-art soft x-ray microscopy zone plates. By decreasing the temperature of the hexyl acetate developer to −50 °C, 11 nm half-pitch gratings have been resolved in the electron-beam resist ZEP 7000. 12 nm half-pitch gratings have been successfully transferred, via the intermediate SiO2 hardmask, into the bottom polyimide layer by CHF3 and O2 reactive ion etching. The trilayer resist, including optimized cold development, has finally been used in an electroplating-based process for the fabrication of nickel zone plates. Zone plates with down to 13 nm outermost zone width have been fabricated and 2.4% average groove diffraction efficiency has been measured for zone plates with 15 nm outermost zone width and a nickel height of 55 nm.
Fabrication of high density, high-aspect-ratio polyimide nanofilters
Authors: Makarova Olga V. , Tang Cha-Mei , Amstutz Platte , Divan Ralu , Imre Alexandra , Mancini Derrick C. , Hoffbauer Mark , Williamson Todd
Published: December 2009

A novel fabrication process produces high porosity polymer nanofilters with smooth, uniform, and straight pores with high aspect ratios. The process utilizes electron beam lithography and energetic neutral atom beam lithography and epitaxy techniques. The method has the potential to produce a new generation of high-precision, very-high-porosity, biocompatible filters with pore sizes down to 100nm.
Resist residues and transistor gate fabrication
Authors: Macintyre D. S. , Ignatova O. , Thoms S. , Thayne I. G.
Published: December 2009

In this article, the authors investigate the formation and removal of resist residues with the main objective to improve the reliability of transistor gate fabrication. Device performance is strongly dependent on the quality of metal contacts and the interface between gate metal and substrates. Reliable transistor fabrication becomes increasingly difficult as transistor dimensions shrink. Residual resist layers can become significant if wet or dry etching steps are required for gate recessing, e.g., for high electron mobility transistors or the removal of thin oxide layers in III-V metal oxide semiconductor field effect transistor fabrication. They observe two sorts of residual resist layers in polymethyl methacrylate (PMMA): exposed and nonexposed. Exposed residuals have been observed by many groups in electron beam exposed and developed regions of PMMA. In this article, they show that the observed granularity lies on top of a continuous residual film and consider this effect on gate fabrication. They also present evidence of a nonexposed residual layer observed in regions of unexposed resist which have been subject to a standard solvent based resist strip and cleaning procedure. They further demonstrate that CV measurement techniques can be used to detect the presence of residual layers of resist.
Spatial dose control for fabrication of saw-tooth structures
Authors: Lee S.-Y. , Jeon S. C. , Kim J. S. , Kim K. N. , Hyun M. S. , Yoo J. J. , Kim J. W.
Published: December 2009

Electron-beam (e-beam) lithography is often employed in the fabrication of three-dimensional structures, i.e., e-beam grayscale lithography where dose is spatially controlled such that the remaining resist profile is as close to the target structure as possible. The resist profile is determined by the developing rate distribution in the resist, which, in turn, depends on the exposure (energy deposited) distribution. In the past, a dose-to-depth relationship derived from experiments was referred to in determining a dose distribution for fabrication of a grayscale structure. However, the relationship is structure dependent since the exposure distribution depends on the dose distribution, i.e., exposure at each point is a function of doses at all points within the electron scattering range. Hence, a more general approach is to consider an exposure-to-depth relationship and dependency of the required exposure distribution on (the shape of) structure. In this study, such an approach has been investigated for saw-tooth structures with varying slope of tooth. Fabricated saw-tooth structures and analysis of slope dependency of the required exposure distribution are presented in this article.
Method of improving the quality of nanopatterning in atomic image projection electron-beam lithography
Authors: Kim Hyun-Mi , Lee Min Hyun , Lee Hyo-Sung , Wi Jung-Sub , Lim Kipil , Kim Ki-Bum
Published: December 2009

The authors demonstrated successful nanopatterning using a high resolution lattice image obtained by transmission electron microscopy (TEM) as a mask signal [H. S. Lee et al., Adv. Mater. (Weinheim, Ger.) 19, 4198 (2007)]. In this process, the quality of the patterning result is critically dependent on the lattice image, which, in turn, is critically dependent on the quality of the mask. It is often noted that the quality of the mask prepared by the conventional TEM sample preparation technique is far from perfect, which critically limits the quality of patterning. In this work, they first discuss the various origins of the noise signal generated by the mask and then introduce a special type of objective aperture (noise reduction aperture) to remove the noise signal. The effect of the noise reduction aperture, designed for the Si [110] zone axis, is experimentally demonstrated.
Design for electron beam: A novel approach to electron beam direct writing throughput enhancement for volume production
Authors: Maruyama Takashi , Machida Yasuhide , Sugatani Shinji , Tsuchikawa Haruo , Hoshino Hiromi , Ito Masaru , Tago Haruyuki , Chau Larry L. , Lee Shone , Komami Hideaki
Published: December 2009

The ordinal shot count reduction in the character projection based electron beam (EB) maskless lithography is done by the recognition of the repeatability of physical design data. Nevertheless, the reduction efficiency is limited to around four times. The new concept of design for electron beam enables a much higher shot count reduction rate of more than ten times and enables a drastic throughput enhancement. Using this method, the authors created an EB friendly design layout data by tracing back to upstream design flow and this is the most characteristic feature of this methodology.