bluuebunny/crossref_metadata_2025 huggingface dataset:
GEOGRAPHICAL SPACE AND EFFECTIVE DEMAND UNDER STAGNATION
Authors: JOHDO WATARU
Published: November 2006

This paper investigates the adjustment mechanism between geographical space and effective demand under stagnation by constructing a spatial model with stagnation included. The model takes the idea of stagnation in Ono (2001) and combines it with the spatial model of Perera‐Tallo (2003). The spatial model features local monopolists that import intermediate goods from other monopolists at a cost that can be decreased through investment. Using the integrated model, we reach the following conclusion: the wider the geographical space, the lower the effective demand under stagnation. This mechanism is explained as follows. Under stagnation, where demand has reached an upper bound, a decrease in the marginal cost of reaching distant intermediate suppliers reduces employment. The reason is ‘love of variety’ in production: for given final output, more variety of available intermediate inputs crowds out per‐variety demand of intermediates and thus employment. Decreases in employment then lead to a decrease in the rate of time preference through a rise in the deflation rate, and thereby decrease the desire for consumption, consequently cutting effective demand.
Relations between episodic memory, suggestibility, theory of mind, and cognitive inhibition in the preschool child
Authors: MELINDER ANNIKA , ENDESTAD TOR , MAGNUSSEN SVEIN
Published: November 2006

The development of episodic memory, its relation to theory of mind (ToM), executive functions (e.g., cognitive inhibition), and to suggestibility was studied. Children (n= 115) between 3 and 6 years of age saw two versions of a video film and were tested for their memory of critical elements of the videos. Results indicated similar developmental trends for all memory measures, ToM, and inhibition, but ToM and inhibition were not associated with any memory measures. Correlations involving source memory was found in relation to specific questions, whereas inhibition and ToM were significantly correlated to resistance to suggestions. A regression analysis showed that age was the main contributor to resistance to suggestions, to correct source monitoring, and to correct responses to specific questions. Inhibition was also a significant main predictor of resistance to suggestive questions, whereas the relative contribution of ToM was wiped out when an extended model was tested.
Changes at work and employee reactions: Organizational elements, job insecurity, and short‐term stress as predictors for employee health and safety
Authors: STØRSETH FRED
Published: November 2006

The objective was to identify focus areas for possible reduction of job insecurity and its outcomes. A model was specified and tested as a prediction model for health and safety. First, a parsimonious model was specified. The model consisted of perceived job insecurity (as a stressor), organizational factors (information quality, leadership style, work task administration), and short‐term stress reactions (job dissatisfaction, reduced work motivation). Second, the model was tested as a prediction model in three separate path analyses, in order to examine the model's contribution in explaining (1) physical health complaints, (2) mental health complaints, and (3) risk taking behavior. A quota sample of Norwegian employees (N= 1,002) was obtained by means of a self‐completion questionnaire survey. The results of the structural equation modeling (path analyses) supported the hypothesized model. Mental health complaints and employee risk taking behavior were significantly predicted (not physical health complaints).
Activation of the galanin receptor 2 (GalR2) protects the hippocampus from neuronal damage
Authors: Elliott‐Hunt Caroline R. , Pope Robert J. P. , Vanderplank Penny , Wynick David
Published: November 2006

Expression of the neuropeptide galanin is up‐regulated in many brain regions following nerve injury and in the basal forebrain of patients with Alzheimer's disease. We have previously demonstrated that galanin modulates hippocampal neuronal survival, although it was unclear which receptor subtype(s) mediates this effect. Here we report that the protective role played by galanin in hippocampal cultures is abolished in animals carrying a loss‐of‐function mutation in the second galanin receptor subtype (GalR2‐MUT). Exogenous galanin stimulates the phosphorylation of the serine/threonine kinase Akt and extracellular signal‐regulated kinase (ERK) in wild‐type (WT) cultures by 435 ± 5% and 278 ± 2%, respectively. The glutamate‐induced activation of Akt was abolished in cultures from galanin knockout animals, and was markedly attenuated in GalR2‐MUT animals, compared with WT controls. In contrast, similar levels of glutamate‐induced ERK activation were observed in both loss‐of‐function mutants, but were further increased in galanin over‐expressing animals. Using specific inhibitors of either ERK or Akt confirms that a GalR2‐dependent modulation in the activation of the Akt and ERK signalling pathways contributes to the protective effects of galanin. These findings imply that the rise in endogenous galanin observed either after brain injury or in various disease states is an adaptive response that reduces apoptosis by the activation of GalR2, and hence Akt and ERK.
SCAPHOPODIZATION IN PALAEOZOIC MOLLUSCS
Authors: PEEL JOHN S.
Published: November 2006

Abstract:  The relationship of a variety of problematic Early Palaeozoic fossils to the true scaphopods (Late Palaeozoic–Recent) is clarified by the recognition that a trend towards the development of a tubular shell is a recurrent theme within Palaeozoic benthic molluscs. This trend is here termed scaphopodization and can be recognized already in the Cambrian in helcionelloids such as Yochelcionella and Eotebenna. The problematic Early Palaeozoic tubular fossils Janospira, Jinonicella and Rhytiodentalium are interpreted as pseudo‐scaphopod derivatives of the apparently exogastric ribeirioid rostroconchs. The direction of coiling of the protoconch indicates that they are not closely related to the true scaphopods, which were derived from endogastric concocardioidean rostroconchs in the Devonian or Carboniferous. Scaphopods show a comparable underlying morphological blueprint to these conocardioideans, but they represent a distinct stream‐lining to the infaunal habitat.
Interactions between radiation therapy and immunotherapy: the best of two worlds?
Authors: Thamm D. H.
Published: November 2006

Contrary to earlier thought, there is now accumulating evidence that local radiation therapy and various form of immunotherapy may be complementary. This may occur as a result of radiation‐induced changes to the tumour cells themselves, the tumour microenvironment, the tumour vasculature and modulation of antigen‐presenting and effector cell function. This study discusses recent findings and potential applications of this apparent synergy.
Afterclearing by ozonation: a novel approach for disperse dyeing of polyester
Authors: Eren Hüseyin Aksel
Published: November 2006

A set of trials has been conducted to examine the efficiency of ozonation afterclearing on poly(ethylene terephthalate) fibres dyed with disperse dyes. The afterclearing process was performed in neutral distilled water at room temperature with 12.8 ± 0.3 mg/min ozone at 400 ml/min ozone gas flow rate. The results indicate that 1 min ozonation time is adequate to achieve wash fastness results comparable with conventional reduction clearing without significant colour yield losses. Ozonation periods greater than 1 min not only caused significant colour yield losses, but also caused a severe decrease of the breaking load of the fabric. The advantages of ozonation afterclearing are: savings in energy and time, as it is performed at room temperature for only 1 min, and decrease of environmental load as it avoids the use of the harsh chemicals used in conventional reduction clearing.
Topographic Movie of Ictal High‐Frequency Oscillations on the Brain Surface Using Subdural EEG in Neocortical Epilepsy
Authors: Akiyama Tomoyuki , Otsubo Hiroshi , Ochi Ayako , Galicia Elaine Z. , Weiss Shelly K. , Donner Elizabeth J. , Rutka James T. , Snead O. Carter
Published: November 2006

Summary:  Purpose: To understand the rapid dynamic changes of ictal intracranial high‐frequency oscillations (HFOs) in neocortical epilepsy.

Methods: We integrated multiple band frequency analysis and brain‐surface topographic maps of HFOs from ictal subdural EEG (SDEEG) recordings. We used SDEEG to record partial seizures consisting of right‐arm jerks with secondary generalization in a 17‐year‐old right‐handed girl. We selected 20‐s EEG sections that included preclinical seizure recordings. We averaged the HFO power between 60 and 120 Hz for 25 selected electrodes, made topographic maps from these averaged powers, and superimposed the maps on the brain‐surface image. We filmed consecutive HFO maps at a 10‐ms frame rate.

Results: Before clinical seizure onset, high‐power HFOs emerged at the superior portion of the left precentral gyrus, then appeared in the middle of the left postcentral gyrus, and subsequently reverberated between both regions as well as the posterior portion of the left postcentral gyrus. Right‐arm extension and facial grimacing started as the HFO power decreased. As generalized tonic–clonic seizures evolved, HFO power increased but remained within the central region.

Conclusions: Topographic movies of intracranial HFOs on the brain surface allow visualization of the dynamic ictal changes in neocortical epilepsy.
LACK OF DEFENSE OR PHLOROTANNIN INDUCTION BY UV RADIATION OR MESOGRAZERS IN DESMARESTIA ANCEPS AND D. MENZIESII (PHAEOPHYCEAE)1
Authors: Fairhead Victoria A. , Amsler Charles D. , McClintock James B. , Baker Bill J.
Published: November 2006

Phlorotannins are polyphenoloic metabolites occurring only in the Phaeophyceae that have numerous putative primary roles (e.g. cell‐wall construction and storage) as well as secondary metabolic roles, which include herbivore feeding deterrence and protection from UV radiation. The proposed role of phlorotannins in the defense against UV radiation is of particular importance in the Antarctic due to depletion of the stratospheric ozone layer in that area. Several studies of brown algae have found evidence of an induction response (the production of defensive metabolites, including phlorotannins) after grazing by various mesograzers, after simulated grazing/wounding, and after exposure to increases in UV radiation. This study aimed to determine if phlorotannin production or other defenses in two dominant, endemic Antarctic species (Desmarestia menziesii Montagne and Desmarestia anceps J. Agardh) could be induced by an increase in exposure to UV radiation or by natural and artificial grazing. An in situ experiment failed to detect any effect of UV radiation on phlorotannin concentrations in either species or on subsequent palatability in feeding bioassays. A laboratory‐based experiment did not detect any effect of mesoherbivore grazing or simulated grazing (wounding) on palatability or the concentration of phlorotannins in D. menziesii. Instead, phlorotannin concentrations increased in all treatments in both experiments, consistent with an increase in overall resource availability due to an increase in available PAR compared with the in situ irradiance at the algal collection sites.
The Inevitability of Marketwide Underpricing of Mortgage Default Risk
Authors: Pavlov Andrey , Wachter Susan M.
Published: November 2006

Lenders are frequently accused of mispricing the put option embedded in nonrecourse lending. Prior research shows one lender's incentives to underprice. Here, we identify the conditions for a marketwide underpricing equilibrium. We demonstrate that, in a market with many players, given sufficient time, a race to the bottom and marketwide mispricing are inevitable. Underpricing occurs because bank managers and shareholders exploit mispriced deposit insurance. We show that the probability of the underpricing equilibrium increases with time since the previous market crash and that the more volatile the underlying asset market, the more likely it is subject to underpricing.
Housing Density and the Effect of Proximity to Public Open Space in Aberdeen, Scotland
Authors: Dehring Carolyn , Dunse Neil
Published: November 2006

We consider whether public recreational open space is a substitute for private open space by testing whether price effects from proximity to an urban park are increasing in housing density. Aberdeen, Scotland features three owner‐occupied residential property types: detached housing, nondetached housing and flats. We examine property sales within 800 m of five city parks. We find flat prices increase with additional proximity to parks, but there are generally no price effects from park proximity for lower density housing types. The results suggest that open space policy must consider the scale and density of surrounding urban development.
Do Hispanic and Asian Adolescents Practice Panethnicity in Friendship Choices?*
Authors: Kao Grace , Joyner Kara
Published: November 2006

Objectives. Using data from the National Longitudinal Study of Adolescent Health (Add Health), we investigate whether Asian and Latino youth value racial boundaries more than ethnic boundaries. We evaluate the relative preferences of same‐ethnic, same‐race (but different‐ethnic), and different‐race friends.

Methods. We use multilevel multinomial logistic regression models to examine the odds of choosing same‐ethnic, different‐ethnic (but same‐race), and different‐race friends net of the opportunity to interact.

Results. We find strong effects of school racial and ethnic composition, immigrant status, and parental education on the likelihood of crossing boundaries in the selection of friends. In addition, we develop a new scale of panethnicity and find substantial ethnic group variation in panethnic sentiment.

Conclusion. We find an overwhelming preference for same‐ethnic peers over same‐race (different‐ethnic) and different‐race peers.
The Behavior and Success of Latino Legislators: Evidence from the States*
Authors: Bratton Kathleen A.
Published: November 2006

Objectives. Research on the link between descriptive and substantive representation has focused almost exclusively on women and African Americans. In the last two decades, Latino representation in state legislatures has more than doubled, yet scholars have only begun to examine the policy interests and legislative success of these legislators. The objectives of this study are to test a descriptive representation model, in which the ethnicity of the legislator influences legislative behavior even after accounting for the ethnic composition of the district, and to examine ethnic differences in legislative success.

Methods. Multivariate regression analyses are used to examine the effect of legislator ethnicity and district composition on bill sponsorship, committee service, and bill passage in seven U.S. legislatures.

Results. I find that both constituency composition and the ethnicity of the legislator influence legislative behavior. The success of measures sponsored by Latino legislators varies substantially across states.

Conclusions. I conclude that both the ethnicity of the legislator and the composition of the district influence legislative behavior and success. There is clear support for a descriptive representation model of agenda setting, particularly on issues involving immigration. However, this link between descriptive and substantive varies substantially by political context.
Constructing Interracial Families Through Intercountry Adoption*
Authors: Ishizawa Hiromi , Kenney Catherine T. , Kubo Kazuyo , Stevens Gillian
Published: November 2006

Objective. This article analyzes the role of race and ethnicity in constructing American families through intercountry adoption. We argue that such adoptions illustrate the fluidity and tenacity of specific racial boundaries in American families.

Methods. Data are drawn from the U.S. 2000 Census—the first to contain information on children's adoptive status—to examine whether race of parents and adopted children match and whether racial matching varies by the characteristics of adoptive families and adopted children.

Results. Our findings indicate that minority‐race parents are more likely than white parents to adopt a child of the same race as themselves, and that the odds of white parents, in particular, adopting a white versus nonwhite child from abroad are related to factors such as the age, sex, and health status of the child, as well the presence of other children in the household.

Conclusion. Parents weigh a constellation of factors, including attributes of the adopted child and the children already in the household, when adopting a child of the same or different race from abroad.
Metastatic myxoid melanoma with partial regression of the primary lesion
Authors: Inoue Takuya , Misago Noriyuki , Narisawa Yutaka
Published: November 2006

Myxoid melanoma is a rare variant of malignant melanoma. The diagnostic problems are obviously increased when it presents as amelanotic metastasis in a lymph node. An 82‐year‐old woman presented a subcutaneous mass in the right axilla. A thorough clinical investigation disclosed a pigmented black lesion on the right forearm. The right axillary lymph nodes and the pigmented lesion were resected. In the lymph nodes, proliferation of tumor cells with an abundant mucous substrate was noted. The cells proliferated in a variable pattern, and there were no melanin granules detected on hematoxylin–eosin‐stained sections. However, we found melanin granules in the tumor cells observed under electron microscopy. In the pigmented lesion of the right forearm, there were small clusters of tumor cells with melanin granules, suggesting malignant melanoma. In the present case, myxoid metastasis occurred with the partial spontaneous disappearance of the primary nonmyxoid malignant melanoma.
Histologic mimickers of mycosis fungoides: a review
Authors: Reddy Kavitha , Bhawan Jag
Published: November 2006

Abstract:  Mycosis fungoides (MF) is a rare type of non‐Hodgkin’s lymphoma affecting the skin. Because MF develops slowly over several years and may have a variety of clinical presentations, including itchy patches, plaques or tumors that may be confused with common benign conditions such as eczema and psoriasis, the disease presents a diagnostic challenge. The average time to diagnosis varies but is frequently as long as 3 to 6 years. Skin biopsies frequently reveal non‐specific features of several dermatoses; thus, histologic evaluation of the disease is also challenging. Importantly, various significant and/or benign conditions may mimic MF histologically and result in a misdiagnosis of MF. Here we review the reported histologic mimickers of MF and discuss both similar and differentiating features of each, in order to aid in more accurate interpretation of diagnostically challenging skin biopsies. Clinicopathologic correlation is ultimately essential to make accurate diagnosis of MF and its histologic mimickers.
Do Divorce Law Reforms Matter for Divorce Rates? Evidence from Portugal
Authors: Coelho Clarisse , Garoupa Nuno
Published: November 2006

The effect of divorce law reforms on divorce rates in the United States and elsewhere has generated a controversy in the law and economics literature. In this article, we study the contribution of divorce law reforms for the evolution of divorce rates in Portugal over the last 40 years. We focus on the reforms of divorce law in the 1970s and in the 1990s as well as socioeconomic factors as determinants of the divorce rate. We find that the introduction of a modern divorce law in the 1970s had a significant effect on the divorce rate, but the changes of the 1990s that effectively implemented a generalized no‐fault regime had no statistically significant impact. Our observations suggest that the reforms in the 1990s were likely the response of the legislature to growing divorce rates rather than the cause.
Explaining Deviations from Absolute Priority Rules in Bankruptcy
Authors: Carapeto Maria
Published: November 2006

This article provides a classification of the reasons behind deviations from absolute priority (DAPs) in Chapter 11 bankruptcies and tests several explanations using a regression approach. DAPs seem to be best explained by two main reasons, a recontracting process and bargaining power of the debtor. The introduction of nonlinearities in the analysis provides some conditional support for two other reasons—asymmetric information and complexity of the cases. The study found no backing for an alternative reason, the bankruptcy venue. Even though DAPs are present in most Chapter 11 cases, the results show that their magnitude has been decreasing over time.
Application of a Simple Decision Model for Soil Vapor Extraction System Operation
Authors: Barnes David L. , White Trevor C.
Published: November 2006

Over the past several decades, soil vapor extraction (SVE) systems have successfully reduced the mass of volatile organic compounds in contaminated soils at many sites. However, predicting when operation of these systems should end once mass removal rates decline and become asymptotic to some low value is still a difficult task. To help make this decision, a simple decision model has been derived from a more rigorous cost‐risk‐based objective function that requires extensive Monte Carlo analyses. Use of the simple model to make a decision on continued operation does not require the same extensive modeling effort. Yet, use of the model does require the contaminant removal rate to be asymptotic to some low value indicating that the removal process has become dominated by diffusion from relatively low permeable soil. At this stage of the removal process, the SVE system should be replaced with an alternative approach if the cost of this alternative approach is less than the capital cost of continued SVE system operation. Applicability of the simple model is discussed through a comparison of the results predicted by the simple model for an operating SVE system to the rigorous results determined with the objective function. Results from this study show that under most conditions the simple model can be used to make a decision of whether a SVE system should continue to operate.
A Field and Modeling Study to Determine Pesticide Occurrence in a Public Water Supply in Northern England, UK
Authors: Stuart Marianne E. , Gooddy Daren C. , Hughes Andrew G. , Jackson Christopher R.
Published: November 2006

In the UK, increasing numbers of pesticides are being detected in ground water as monitoring programs are developed and analytic techniques are refined. This study describes the investigation of pesticides at a site on the Triassic Sandstone aquifer of northern England. Drilling and pore water sampling demonstrated the presence of agricultural herbicides in the unsaturated zone of the aquifer close to a public supply well site at which elevated pesticide concentrations had been detected in the abstracted ground water. These were similar to the compounds detected in the supply wells, but there was no evidence for some of these having been used at the nearby farm. Modeling of water movement to wells showed that individual ground water flow subcatchments were retained during a monthly duty cycle and should be well‐defined. Detecting and quantifying the sources of pesticide pollution of ground water was unsuccessful, probably due to local land use and aquifer heterogeneity. This remains difficult even where the overall catchment is small (1‐km radius) and there are apparently few possible point sources. Even with sophisticated flow models, there is still a high degree of uncertainty in modeling pesticide movement, and treatment of ground water may be the only viable option for water utilities.
Use of Plume Mapping Data to Estimate Chlorinated Solvent Mass Loss
Authors: Barbaro Jeffrey R. , Neupane Pradumna P.
Published: November 2006

Results from a plume mapping study from November 2000 through February 2001 in the sand‐and‐gravel surficial aquifer at Dover Air Force Base, Delaware, were used to assess the occurrence and extent of chlorinated solvent mass loss by calculating mass fluxes across two transverse cross sections and by observing changes in concentration ratios and mole fractions along a longitudinal cross section through the core of the plume. The plume mapping investigation was conducted to determine the spatial distribution of chlorinated solvents migrating from former waste disposal sites. Vertical contaminant concentration profiles were obtained with a direct‐push drill rig and multilevel piezometers. These samples were supplemented with additional ground water samples collected with a minipiezometer from the bed of a perennial stream downgradient of the source areas. Results from the field program show that the plume, consisting mainly of tetrachloroethylene (PCE), trichloroethene (TCE), and cis‐1,2‐dichloroethene (cis‐1,2‐DCE), was approximately 670 m in length and 120 m in width, extended across much of the 9‐ to 18‐m thickness of the surficial aquifer, and discharged to the stream in some areas. The analyses of the plume mapping data show that losses of the parent compounds, PCE and TCE, were negligible downgradient of the source. In contrast, losses of cis‐1,2‐DCE, a daughter compound, were observed in this plume. These losses very likely resulted from biodegradation, but the specific reaction mechanism could not be identified. This study demonstrates that plume mapping data can be used to estimate the occurrence and extent of chlorinated solvent mass loss from biodegradation and assess the effectiveness of natural attenuation as a remedial measure.
Permeable Reactive Barriers for the Removal of Heavy Metals: Lab‐Scale Experiments with Low‐Grade Magnesium Oxide
Authors: Navarro Andrés , Chimenos Josep M , Muntaner David , Fernández A. Inés
Published: November 2006

The attenuation of heavy metals in ground water depends on factors such as solid‐solution equilibrium or the solubility product (Ksp) of the solid phase. Metals are pH dependent, and the solubility of heavy metal hydroxides such as lead, cadmium, zinc, and nickel is minimal within pH range 9 to 11. MgO as material in a passive remediation system for removing heavy metals from contaminated ground water is very useful because of its minimal environmental impact and low solubility reaches a maximum pH of 10. Low‐grade MgO (LG‐MgO) was found to be suitable and economically feasible for use as permeable reactive barrier filler for remediation of ground water contaminated by heavy metals. The results of this study suggest that the coprecipitation of heavy metal hydroxides and magnesium hydroxide on the LG‐MgO particle surface and sorption in the neoformed precipitates are the main mechanisms of heavy metal release from contaminated ground water. Remediation is not affected by the presence of other metals, which ensures that the range of application is very broad in both subterranean and surface water. LG‐MgO used as a reactive medium for the treatment of contaminated water significantly diminishes the amount of heavy metals in ground water.
Neurotrophic Factors in Neurodegeneration
Authors: Blesch Armin
Published: November 2006

Neurotrophic factors (NTFs) have the unique potential to support neuronal survival and to augment neuronal function in the injured and diseased nervous system. Numerous studies conducted over the last 20 years have provided evidence for the potent therapeutic potential of NTFs in animal models of neurodegenerative diseases. However, major obstacles for the therapeutic use of NTFs are the inability to deliver proteins across the blood‐brain‐barrier, and dose‐limiting adverse effects resulting from the broad exposure of nontargeted structures to NTFs. Two recent developments have allowed NTFs’ promise to be truly tested for the first time: first, recent improvements in viral vectors that allow the targeted delivery of NTFs while providing a long‐lasting supply and sufficient therapeutic doses of NTFs; and second, improved animal models developed in recent years. In this review, we will discuss some of the potential therapeutic applications of NTFs in neurodegenerative diseases and the potential contribution of disturbed neurotrophic factor signaling to neurodegenerative diseases.
Modified Equation To Predict Leak/Rupture Criteria For Axially Through-Wall Notched X80 and X100 Linepipes Having a Higher Charpy Energy
Authors: Kawaguchi Shinobu , Hagiwara Naoto , Ohata Mitsuru , Toyoda Masao
Published: November 2006

A method of predicting the leak/rupture criteria for API 5L X80 and X100 line pipes was evaluated based on the results of hydrostatic full-scale tests for X60, X65, X80, and X100 line pipes with an axially through-wall (TW) notch. The TW notch test results defined the leak/rupture criteria, that is, the relationship between the initial notch lengths and the maximum hoop stresses during the TW notch tests. The defined leak/rupture criteria were then compared to the prediction of the Charpy V-notch (CVN) absorbed energy-based equation, which has been proposed by Kiefner, Maxey et al. This comparison revealed that the CVN-based equation was not applicable to the pipes having both a CVN energy greater than 120 or 130 J and flow stress greater than the level of X65. In order to predict the leak/rupture criteria for these line pipes, the static absorbed energy for ductile cracking, (Cvs)i, was introduced as representing the fracture toughness of a pipe material. The (Cvs)i value was determined from the microscopic observation of the cut and polished Charpy V-notch specimens after static three-point bending tests. The CVN energy in the original CVN-based equation was replaced by an equivalent CVN energy, (Cv)eq, which was defined as follows: (Cv)eq=4.5(Cvs)i. The leak/rupture criteria for the X80 and X100 line pipes with higher CVN energies were reasonably predicted by the modified equation using the (Cvs)i value.
Section XII Transport Tank Code Preview—Cargo Tanks
Authors: Paulick Nick , Rogers Tom
Published: November 2006

ASME Section XII Transport Tank Code will have an impact on the regulations related to the construction and continued service of highway cargo tanks used in the transportation of dangerous goods. Modal Appendix 1 of this code specifically addresses these transport tanks, and is intended to replace a large portion of the DOT regulations currently governing how they are built and serviced. This paper presents a preview of Modal Appendix 1, one of the mandatory appendices related to cargo tanks, and how these changes will affect manufacturers and repair shops.
3-Omega Measurements of Vertically Oriented Carbon Nanotubes on Silicon
Authors: Hu X. Jack , Padilla Antonio A. , Xu Jun , Fisher Timothy S. , Goodson Kenneth E.
Published: November 2006

An exploratory thermal interface structure, made of vertically oriented carbon nanotubes directly grown on a silicon substrate, has been thermally characterized using a 3-omega method. The effective thermal conductivities of the carbon nanotubes (CNT) sample, including the effects of voids, are found to be 74W∕mK to 83W∕mK in the temperature range of 295K to 323K, one order higher than that of the best thermal greases or phase change materials. This result suggests that the vertically oriented CNTs potentially can be a promising next-generation thermal interface solution. However, fairly large thermal resistances were observed at the interfaces between the CNT samples and the experimental contact. Minimizing these contact resistances is critical for the application of these materials.
Self-Consistent Open-Celled Metal Foam Model for Thermal Applications
Authors: Schmierer Eric N. , Razani Arsalan
Published: November 2006

Many engineering applications require thermal cycling of granular materials. Since these materials generally have poor effective thermal conductivity various techniques have been proposed to improve bed thermal transport. These include insertion of metal foam with the granular material residing in the interstitial space. The use of metal foam introduces a parasitic thermal capacitance, disrupts packing, and reduces the amount of active material. In order to optimize the combined high porosity metal foam-granular material matrix and study local thermal nonequilibrium, multiple energy equations are required. The interfacial conductance coefficients, specific interface area, and the effective thermal conductivities of the individual components, which are required for a multiple energy equation analysis, are functions of the foam geometry. An ideal three-dimensional geometric model of open-celled Duocell® foam is proposed. Computed tomography is used to acquire foam cell and ligament diameter distribution, ligament shape, and specific surface area for a range of foam parameters to address various shortcomings in the literature. These data are used to evaluate the geometric self-consistency of the proposed geometric model with respect to the intensive and extensive geometry parameters. Experimental thermal conductivity data for the same foam samples are acquired and are used to validate finite element analysis results of the proposed geometric model. A simple relation between density and thermal conductivity ratio is derived using the results. The foam samples tested exhibit a higher dependence on relative density and less dependence on interstitial fluid than data in the literature. The proposed metal foam geometric model is shown to be self-consistent with respect to both its geometric and thermal properties.
Strain mediated reconstructions and indium segregation on InGaAs∕GaAs(001) alloy surfaces at intermediate lattice mismatch
Authors: Riposan A. , Mirecki Millunchick J. , Pearson Chris
Published: November 2006

In vacuo scanning tunneling microscopy is used to investigate the surface reconstructions of pseudomorphic InGaAs alloys at intermediate values of compressive strain. The coverage of different reconstructions varies with film thickness, concomitant with changes in composition and strain at the surface arising from In segregation and changes in surface morphology. Thin samples exhibit mainly disordered (1×3) reconstructions along with small regions of incommensurate (1×2). With increasing thickness, the (1×3) transforms into more regular (4×3) or c(4×6), whose coverage mirrors the increase and saturation of In surface composition. Regions of α2(2×4) reconstructions are also present, and their coverage initially increases with In surface composition, but later decreases upon saturation of In at the surface. This decrease is concurrent with the onset of surface roughening, suggesting that the α2(2×4) reconstruction is strain stabilized.
Thermally induced structural changes in nanoporous silicon dioxide from x-ray photoelectron spectroscopy
Authors: Soh Martin T. K. , Thomas J. H. , Talghader Joseph J.
Published: November 2006

Morphological changes due to adsorbed gases in nanoporous silicon dioxide thin films are demonstrated using in situ x-ray photoelectron spectroscopy at temperatures in the range 20⩽T⩽300°C. Adsorbed hydrogen bonded water vapor is observed to relax the surface bond strain of low-temperature electron-beam deposited silicon dioxide up to 100°C. This was determined by measuring the width of the Si 2p and O 1s photoemission peak full widths at half maximum, which are distinctly smaller for films with adsorbed water vapor than for the same films after vapor has been outgassed by heating above 100°C. In situ heating in the range 100<T<200°C decreases the peak width as the atoms gain sufficient energy to establish a more homogeneous local bonding environment. This process is overshadowed above 200°C as thermally induced localized bond strains and charge inhomogeneities at the surface begin to introduce disorder, as demonstrated in the repeatable increase in peak spread with temperature for thermally grown silicon dioxide and quartz. The in vacuo peak width behavior in subsequent thermal cycles is repeatable for the nanoporous thin films. However, if the films are reexposed to atmosphere, the initial increase in peak width is seen again.
Real-time monitoring of charge accumulation during pulse-time-modulated plasma
Authors: Ohtake Hiroto , Jinnai Butsurin , Suzuki Yuya , Soda Shinnosuke , Shimmura Tadashi , Samukawa Seiji
Published: November 2006

The authors investigated real-time monitoring of charge accumulation during pulse-time-modulated plasma processes by using their developed on-wafer monitoring chip. The charge accumulation potential between the top surface and the bottom in a SiO2 contact structure was measured during pulse-time-modulated plasma exposure with an on-wafer monitoring device. In conventional plasma with rf bias, the electron shading effect could be clearly observed as the potential difference between the wafer surface and the contact-hole bottom. Conversely, the accumulated charge in the pulse-time-modulated operation was drastically decreased. Time-resolved electron and ion flows to the SiO2 contact hole were clarified by the on-wafer monitoring. Accordingly, it was confirmed that the on-wafer monitoring is a very effective tool for investigating the local charge accumulation in actual device structures.
Thin film deposition of barium strontium oxide by rf magnetron sputtering
Authors: Liu Yan , Day Christopher M. , Little Scott A. , Jin Feng
Published: November 2006

Barium strontium oxide [(BaSr)O] thin films approximately 1μm in thickness were deposited on tungsten substrates using rf magnetron sputter deposition for thermionic cathode applications. Three substrate temperatures ranging from 25to700°C were used in the deposition processes to create oxide films with different surface morphologies and crystalline structures. The films were characterized with scanning electron microscopy and their surface morphologies were correlated to their thermionic emission properties. The results showed that the surface morphology and crystalline structure of the oxide films strongly affected the emission properties. The oxide film deposited at the lowest substrate temperature of 25°C showed a rough surface and a crystalline structure consisting of nanograins. At higher substrate temperatures, the oxide films exhibited smooth surfaces and close-packed crystalline structures with larger grains. The work function of the oxide films was reduced and the emission current density increased as a result of the increase in the growth temperature. The (BaSr)O film made at 700°C exhibited the lowest work function of 1.57eV and the largest emission current density of 1.60A∕cm2 at 1198K under an electrical field of 0.88V∕μm. The emission current density and the work function of the (BaSr)O thin film cathodes were stable over the testing period of 8h. Compared to the traditional cathode fabrication process, which involves the coating of carbonates followed by an activation process, rf magnetron sputtering has a greater ability to control the deposition parameters, which makes it a valuable alternative technique to fabricate oxide cathodes.
Scattering from the mixed layer base into the sound shadow
Authors: Rudnick Daniel L. , Munk Walter
Published: November 2006

Long-range sound transmissions in the ocean are largely controlled by the SOFAR wave guide. The agreement between the measured and predicted arrival patterns is generally excellent, except for an observed extension downward by many hundreds of meters from the lower caustics into the deep sound shadow. The deepening of early arrivals is proposed to be associated with the sharp transition zone marking the lower boundary of the surface mixed layer. This mixed layer base (MLB) is distorted by internal waves. Multiple collisions of the ray-like acoustic transmission with the wavy MLB lead to a mean deepening of the lower caustics of 2γa−1σ2≈35m per collision, where γa=(1∕C)dC∕dz=1.13×10−2km−1 is the (fractional) abyssal adiabatic sound speed gradient and σ2=2×10−4 is the variance in MLB slope. There are typically 20 such collisions in a 1000km transmission. Monte Carlo numerical experiments yield statistics of ray inclination, range, travel time, and lower turning point. The resulting time front includes a deepening by several hundred meters. The acoustic signatures provide the possibility for monitoring upper ocean processes with abyssal acoustic arrays.
Perception of synthetic vowel exemplars of 4 year old children and estimation of their corresponding vocal tract shapes
Authors: McGowan Richard S.
Published: November 2006

Formant scalings for vowel exemplars of American 4 year olds who were imitating adult production were used along with published data of American adult male vowel production to synthesize /ɑ, æ, u, i/. Other vowel exemplars were also synthesized. Adult listeners were asked to categorize these synthetic vowels in a forced choice task. With some exceptions, the formant frequencies preferred for the vowels /ɑ, æ, u, i/ were close to the published data. In order to gain insight on children’s articulation during imitation of vowels /ɑ, æ, u, i/, a five-tube model was used in an algorithm to infer vocal tract shape from the first three formant frequencies of the adult productions, the formant frequencies derived for 4 year olds by scaling, and formant frequencies for 4 year olds derived based on the listening experiments. It was found that the rear tube length for the children, in proportionate terms, was nearly always greater than that of the adult. The rear tube length was proportionately twice as long in children compared to adults for the vowel /u/. Tongue root flexibility and the oblique angle between the pharynx and mouth may be more important than pharynx length in determining formant scalings for 4 year old children.
On the influence of interaural differences on temporal perception of masked noise bursts
Authors: Schimmel Othmar , Kohlrausch Armin
Published: November 2006

In this research, the influence of interaural differences on temporal positioning of the perceived onset of a dichotic broadband noise target in a diotic broadband noise masker was explored. Interaural time or level differences, a combination of these differences, and filtering with head-related transfer functions were applied to broadband noise bursts, to establish lateralization in quiet at center and right positions in the lateral plane. While applying these interaural differences, the subjects’ ability to accurately align the noise’s onset to the meter of a regular series of diotic reference onsets was investigated for various signal-to-noise ratios. At high target sensation levels, mean onset positions were close to physical isochrony and no systematic differences in temporal positioning due to different interaural cues were observed. At low target sensation levels, positioning accuracy decreased with a decreasing signal-to-noise ratio, and dichotic targets were positioned less accurately than diotic targets. This reduced temporal positioning accuracy could not be attributed to differences in detectability of the targets just above the threshold, nor to a reduction of effective target bandwidth of dichotic broadband targets. From these results, the reduced accuracy of temporal perception in binaural unmasking conditions may be seen as a consequence of temporal integration in binaural processing.
Measurement and prediction of nonlinearity in outdoor propagation of periodic signals
Authors: Gee Kent L. , Sparrow Victor W. , James Michael M. , Downing J. Micah , Hobbs Christopher M.
Published: November 2006

Far field propagation measurements of high-amplitude periodic signals generated by the U. S. Army Research Laboratory’s Mobile Acoustic Source (MOAS) have been made. The MOAS is a large horn-coupled electropneumatic loudspeaker capable of producing sound at a few hundred hertz with a maximum overall sound pressure level of 155dBre20μPa at 1m. The possible influence of nonlinear effects have been investigated because the measurements exhibit greater sound pressure levels at high harmonics than are predicted by a linear propagation model. Between 100 and 375m, nonlinearly predicted spectra obtained via a generalized Burgers equation-based model are consistently closer to measured spectra than are linear predictions, according to calculations of mean absolute error. These comparisons strengthen the assertion that nonlinearity is, in fact, the primary cause of disagreement between the measured and linearly predicted spectra at high frequencies. Comparisons between the nonlinear model and measurements, however, yield increased errors for greater propagation distances (∼1km) and for measurements made later in the afternoon. For these cases, the nonlinear model calculations generally predict greater sound pressure levels at high frequencies than are actually present in the MOAS measurements. Despite the increased errors for these latter comparisons, the nonlinear model still typically performs better than the linear model. This provides additional confirmation of the presence of nonlinearity in the propagation, but may also point to the need to account for atmospheric variability in the numerical model to provide improved predictions.
Acoustic source detection and localization based on wavefield decomposition using circular microphone arrays
Authors: Teutsch Heinz , Kellermann Walter
Published: November 2006

This paper is concerned with the problem of detecting and localizing multiple wideband acoustic sources by applying the notion of wavefield decomposition using circular microphone arrays optionally mounted into cylindrical baffles. The decomposed wavefield representation is used to serve as a basis for so-called modal array signal processing algorithms, which have the significant advantage over classical array signal processing algorithms that they inherently support multiple wideband acoustic sources. A rigorous derivation of modal array signal processing algorithms for source detection and localization, as well as performance evaluations, by means of measurements using an actual real-time capable implementation are presented.
Cluster analysis and robust use of full-field models for sonar beamforming
Authors: Tracey Brian , Lee Nigel , Turaga Srinivas
Published: November 2006

Multipath propagation in shallow water can lead to mismatch losses when single-path replicas are used for horizontal array beamforming. Matched field processing (MFP) seeks to remedy this by using full-field acoustic propagation models to predict the multipath arrival structure. Ideally, MFP can give source localization in range and depth as well as detection gains, but robustly estimating range and depth is difficult in practice. The approach described here seeks to collapse full-field replica outputs to bearing, which is robustly estimated, while retaining any signal gains provided by the full-field model. Cluster analysis is used to group together full-field replicas with similar responses. This yields a less redundant “sampled field” describing a set of representative multipath structures for each bearing. A detection algorithm is introduced that uses clustering to collapse beamformer outputs to bearing such that signal gains are retained while increases in the noise floor are minimized. Horizontal array data from SWELLEX-96 are used to demonstrate the detection benefits of sampled field as compared to single-path beamforming.