Showing papers by "Drexel University published in 2006"
TL;DR: The results challenge the long-held axiom that pores smaller than the size of solvated electrolyte ions are incapable of contributing to charge storage.
Abstract: Carbon supercapacitors, which are energy storage devices that use ion adsorption on the surface of highly porous materials to store charge, have numerous advantages over other power-source technologies, but could realize further gains if their electrodes were properly optimized. Studying the effect of the pore size on capacitance could potentially improve performance by maximizing the electrode surface area accessible to electrolyte ions, but until recently, no studies had addressed the lower size limit of accessible pores. Using carbide-derived carbon, we generated pores with average sizes from 0.6 to 2.25 nanometer and studied double-layer capacitance in an organic electrolyte. The results challenge the long-held axiom that pores smaller than the size of solvated electrolyte ions are incapable of contributing to charge storage.
3,348 citations
TL;DR: Work-family enrichment as discussed by the authors is defined as the extent to which experiences in one role improve the quality of life in the other role, and it is used as a way to measure the effect of work-life transitions.
Abstract: We define work-family enrichment as the extent to which experiences in one role improve the quality of life in the other role. In this article we propose a theoretical model of work-family enrichment and offer a series of research propositions that reflect two paths to enrichment: an instrumental path and an affective path. We then examine the implications of the model for future research on the work-family enrichment process.
2,900 citations
TL;DR: The 16 meta-analyses reviewed support the efficacy of CBT for many disorders and are consistent with other review methodologies that also provide support for the efficacy CBT.
2,856 citations
TL;DR: This article describes the latest development of a generic approach to detecting and visualizing emerging trends and transient patterns in scientific literature, and makes substantial theoretical and methodological contributions to progressive knowledge domain visualization.
Abstract: This article describes the latest development of a generic approach to detecting and visualizing emerging trends and transient patterns in scientific literature. The work makes substantial theoretical and methodological contributions to progressive knowledge domain visualization. A specialty is conceptualized and visualized as a time-variant duality between two fundamental concepts in information science: research fronts and intellectual bases. A research front is defined as an emergent and transient grouping of concepts and underlying research issues. The intellectual base of a research front is its citation and co-citation footprint in scientific literature—an evolving network of scientific publications cited by research-front concepts. Kleinberg's (2002) burst-detection algorithm is adapted to identify emergent research-front concepts. Freeman's (1979) betweenness centrality metric is used to highlight potential pivotal points of paradigm shift over time. Two complementary visualization views are designed and implemented: cluster views and time-zone views. The contributions of the approach are that (a) the nature of an intellectual base is algorithmically and temporally identified by emergent research-front terms, (b) the value of a co-citation cluster is explicitly interpreted in terms of research-front concepts, and (c) visually prominent and algorithmically detected pivotal points substantially reduce the complexity of a visualized network. The modeling and visualization process is implemented in CiteSpace II, a Java application, and applied to the analysis of two research fields: mass extinction (1981–2004) and terrorism (1990–2003). Prominent trends and pivotal points in visualized networks were verified in collaboration with domain experts, who are the authors of pivotal-point articles. Practical implications of the work are discussed. A number of challenges and opportunities for future studies are identified. © 2006 Wiley Periodicals, Inc.
2,521 citations
Massachusetts Institute of Technology1, University of Arizona2, Princeton University3, Ohio State University4, New York University5, Fermilab6, University of Chicago7, University of Tokyo8, University of Colorado Boulder9, University of Portsmouth10, Lawrence Berkeley National Laboratory11, Pennsylvania State University12, International Centre for Theoretical Physics13, Johns Hopkins University14, Drexel University15, Case Western Reserve University16, Los Alamos National Laboratory17, University of Washington18, University of Cape Town19, New Mexico State University20, University of Pittsburgh21, Eötvös Loránd University22, Harvard University23, United States Department of the Navy24, University of Pennsylvania25, California Institute of Technology26, University of Sussex27, Seoul National University28, Rochester Institute of Technology29, Hungarian Academy of Sciences30
TL;DR: In this paper, the authors employed a matrix-based power spectrum estimation method using pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions.
Abstract: We measure the large-scale real-space power spectrum P(k) using luminous red galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from the Wilkinson Microwave Anisotropy Probe (WMAP). We employ a matrix-based power spectrum estimation method using Pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions, with narrow and well-behaved window functions in the range 0.01h/Mpc 0.1h/Mpc and associated nonlinear complications, yet agree well with more aggressive published analyses where nonlinear modeling is crucial.
1,481 citations
Duke University1, Tufts Medical Center2, Drexel University3, Harvard University4, University of Nebraska Medical Center5, Wayne State University6, University of California, San Francisco7, Cubist Pharmaceuticals8, University of California, Los Angeles9, Beaumont Hospital10, East Carolina University11, Dartmouth College12, Veterans Health Administration13, Denver Health Medical Center14, University of Maryland, Baltimore15, University of Cologne16, Lehigh Valley Hospital17, Cleveland Clinic18, Goethe University Frankfurt19, University of Hawaii at Manoa20, Johns Hopkins University21
TL;DR: Daptomycin (6 mg per kilogram daily) is not inferior to standard therapy for S. aureus bacteremia and right-sided endocarditis and met prespecified criteria for the noninferiority of daptomecin.
Abstract: Background Alternative therapies for Staphylococcus aureus bacteremia and endocarditis are needed. Methods We randomly assigned 124 patients with S. aureus bacteremia with or without endocarditis to receive 6 mg of daptomycin intravenously per kilogram of body weight daily and 122 to receive initial low-dose gentamicin plus either an antistaphylococcal penicillin or vancomycin. The primary efficacy end point was treatment success 42 days after the end of therapy. Results Forty-two days after the end of therapy in the modified intention-to-treat analysis, a successful outcome was documented for 53 of 120 patients who received daptomycin as compared with 48 of 115 patients who received standard therapy (44.2 percent vs. 41.7 percent; absolute difference, 2.4 percent; 95 percent confidence interval, −10.2 to 15.1 percent). Our results met prespecified criteria for the noninferiority of daptomycin. The success rates were similar in subgroups of patients with complicated bacteremia, right-sided endocarditis, a...
1,318 citations
TL;DR: The fourth data release of the Sloan Digital Sky Survey (SDSS) as discussed by the authors includes all survey-quality data taken through 2004 June, including five-band photometric data for 180 million objects selected over 6670 deg2 and 673,280 spectra of galaxies, quasars and stars selected from 4783 deg2 of those imaging data using the standard SDSS target selection algorithms.
Abstract: This paper describes the Fourth Data Release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through 2004 June. The data release includes five-band photometric data for 180 million objects selected over 6670 deg2 and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg2 of those imaging data using the standard SDSS target selection algorithms. These numbers represent a roughly 27% increment over those of the Third Data Release; all the data from previous data releases are included in the present release. The Fourth Data Release also includes an additional 131,840 spectra of objects selected using a variety of alternative algorithms, to address scientific issues ranging from the kinematics of stars in the Milky Way thick disk to populations of faint galaxies and quasars.
1,110 citations
TL;DR: In this article, the authors found that firms with busy boards exhibit lower market-to-book ratios, weaker profitability, and lower sensitivity of CEO turnover to firm performance than those of inside-dominated boards.
Abstract: Firms with busy boards, those in which a majority of outside directors hold three or more directorships, are associated with weak corporate governance. These firms exhibit lower market-to-book ratios, weaker profitability, and lower sensitivity of CEO turnover to firm performance. Independent but busy boards display CEO turnover-performance sensitivities indistinguishable from those of inside-dominated boards. Departures of busy outside directors generate positive abnormal returns. When directors become busy as a result of acquiring an additional directorship, other companies in which they hold board seats experience negative abnormal returns. Busy outside directors are more likely to depart boards following poor performance.
1,094 citations
TL;DR: It is suggested that virtual community managers should emphasize not only the content but also encourage the friendship and social support aspects as well if they wish to increase the success of their virtual community.
Abstract: Understanding the attraction of virtual communities is crucial to organizations that want to tap into their enormous information potential. Existing literature theorizes that people join virtual communities to exchange information and/or social support. Theories of broader Internet use have indicated both entertainment and searching for friendship as motivational forces. This exploratory study empirically examines the importance of these reasons in assessing why people come to virtual communities by directly asking virtual community members why they joined.
The responses to the open-ended question “Why did you join?” were categorized based upon the reasons suggested in the literature. Across 27 communities in 5 different broad types, 569 different reasons from 399 people indicated that most sought either friendship or exchange of information, and a markedly lower percent sought social support or recreation. The reasons were significantly dependent on the grouping of the communities into types. In all the community types information exchange was the most popular reason for joining. Thereafter, however, the reason varied depending on community type. Social support was the second most popular reason for members in communities with health/wellness and professional/occupational topics, but friendship was the second most popular reason among members in communities dealing with personal interests/hobbies, pets, or recreation. These findings suggest that virtual community managers should emphasize not only the content but also encourage the friendship and social support aspects as well if they wish to increase the success of their virtual community.
915 citations
TL;DR: Direct detection of biofilms on MEM biopsy specimens from children with OME and recurrent OM supports the hypothesis that these chronic middle-ear disorders are biofilm-related.
Abstract: ContextChronic otitis media (OM) is a common pediatric infectious disease. Previous studies demonstrating that metabolically active bacteria exist in culture-negative pediatric middle-ear effusions and that experimental infection with Haemophilus influenzae in the chinchilla model of otitis media results in the formation of adherent mucosal biofilms suggest that chronic OM may result from a mucosal biofilm infection.ObjectiveTo test the hypothesis that chronic OM in humans is biofilm-related.Design, Setting, and PatientsMiddle-ear mucosa (MEM) biopsy specimens were obtained from 26 children (mean age, 2.5 [range, 0.5-14] years) undergoing tympanostomy tube placement for treatment of otitis media with effusion (OME) and recurrent OM and were analyzed using microbiological culture, polymerase chain reaction (PCR)-based diagnostics, direct microscopic examination, fluorescence in situ hybridization, and immunostaining. Uninfected (control) MEM specimens were obtained from 3 children and 5 adults undergoing cochlear implantation. Patients were enrolled between February 2004 and April 2005 from a single US tertiary referral otolaryngology practice.Main Outcome MeasuresConfocal laser scanning microscopic (CLSM) images were obtained from MEM biopsy specimens and were evaluated for biofilm morphology using generic stains and species-specific probes for H influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. Effusions, when present, were evaluated by PCR and culture for evidence of pathogen-specific nucleic acid sequences and bacterial growth, respectively.ResultsOf the 26 children undergoing tympanostomy tube placement, 13 (50%) had OME, 20 (77%) had recurrent OM, and 7 (27%) had both diagnoses; 27 of 52 (52%) of the ears had effusions, 24 of 24 effusions were PCR-positive for at least 1 OM pathogen, and 6 (22%) of 27 effusions were culture-positive for any pathogen. Mucosal biofilms were visualized by CLSM on 46 (92%) of 50 MEM specimens from children with OME and recurrent OM using generic and pathogen-specific probes. Biofilms were not observed on 8 control MEM specimens obtained from the patients undergoing cochlear implantation.ConclusionDirect detection of biofilms on MEM biopsy specimens from children with OME and recurrent OM supports the hypothesis that these chronic middle-ear disorders are biofilm-related.
872 citations
TL;DR: This review provides an overview of the dimensions of unequal exposures to environmental pollution (environmental inequality), followed by a discussion of the theoretical literature that seeks to explain the origins of this phenomenon.
Abstract: In this review, we provide an introduction to the topics of environmental justice and environmental inequality. We provide an overview of the dimensions of unequal exposures to environmental pollution (environmental inequality), followed by a discussion of the theoretical literature that seeks to explain the origins of this phenomenon. We also consider the impact of the environmental justice movement in the United States and the role that federal and state governments have developed to address environmental inequalities. We conclude that more research is needed that links environmental inequalities with public health outcomes.
TL;DR: The air oxidation process does not require the use of toxic or aggressive chemicals, catalysts, or inhibitors and opens avenues for numerous new applications of nanodiamond.
Abstract: The presence of large amounts of nondiamond carbon in detonation-synthesized nanodiamond (ND) severely limits applications of this exciting nanomaterial. We report on a simple and environmentally friendly route involving oxidation in air to selectively remove sp2-bonded carbon from ND. Thermogravimetric analysis and in situ Raman spectroscopy shows that sp2 and sp3 carbon species oxidize with different rates at 375−450 °C and reveals a narrow temperature range of 400−430 °C in which the oxidation of sp2-bonded carbon occurs with no or minimal loss of diamond. X-ray absorption near-edge structure spectroscopy detects an increase of up to 2 orders of magnitude in the sp3/sp2 ratio after oxidation. The content of up to 96% of sp3-bonded carbon in the oxidized samples is comparable to that found in microcrystalline diamond and is unprecedented for ND powders. Transmission electron microscopy and Fourier transform infrared spectroscopy studies show high purity 5-nm ND particles covered by oxygen-containing sur...
TL;DR: In this paper, the authors address the issue why some entrepreneurs fail to recognize and exploit opportunities within organizations as well as in the establishment of new ventures, and propose a solution to this problem.
Abstract: Entrepreneurship—the recognition and exploitation of opportunities—is valuable within organizations as well as in the establishment of new ventures. Some studies have addressed the issue why some i...
TL;DR: Results suggest that PANi-gelatin blend nanofibers might provide a novel conductive material well suited as biocompatible scaffolds for tissue engineering.
TL;DR: The authors investigated the reputational impact of financial fraud for outside directors based on a sample of firms facing shareholder class action lawsuits and found that outside directors do not face abnormal turnover on the board of the sued firm but experience a significant decline in other board seats held.
Abstract: We investigate the reputational impact of financial fraud for outside directors based on a sample of firms facing shareholder class action lawsuits. Following a financial fraud lawsuit, outside directors do not face abnormal turnover on the board of the sued firm but experience a significant decline in other board seats held. This decline in other directorships is greater for more severe allegations of fraud and when the outside director bears greater responsibility for monitoring fraud. Interlocked firms that share directors with the sued firm exhibit valuation declines at the lawsuit filing. Fraud-affiliated directors are more likely to lose directorships at firms with stronger corporate governance and their departure is associated with valuation increases for these firms.
TL;DR: The deprivation index was associated with the unadjusted prevalence of preterm birth and low birth weight for white non-Hispanic and to a lesser extent for black non- Hispanic women across the eight sites, suggesting the utility of using a deprivation index for research into neighborhood effects on adverse birth outcomes.
Abstract: Census data are widely used for assessing neighborhood socioeconomic context. Research using census data has been inconsistent in variable choice and usually limited to single geographic areas. This paper seeks to a) outline a process for developing a neighborhood deprivation index using principal components analysis and b) demonstrate an example of its utility for identifying contextual variables that are associated with perinatal health outcomes across diverse geographic areas. Year 2000 U.S. Census and vital records birth data (1998–2001) were merged at the census tract level for 19 cities (located in three states) and five suburban counties (located in three states), which were used to create eight study areas within four states. Census variables representing five socio-demographic domains previously associated with health outcomes, including income/poverty, education, employment, housing, and occupation, were empirically summarized using principal components analysis. The resulting first principal component, hereafter referred to as neighborhood deprivation, accounted for 51 to 73% of the total variability across eight study areas. Component loadings were consistent both within and across study areas (0.2–0.4), suggesting that each variable contributes approximately equally to “deprivation” across diverse geographies. The deprivation index was associated with the unadjusted prevalence of preterm birth and low birth weight for white non-Hispanic and to a lesser extent for black non-Hispanic women across the eight sites. The high correlations between census variables, the inherent multidimensionality of constructs like neighborhood deprivation, and the observed associations with birth outcomes suggest the utility of using a deprivation, index for research into neighborhood effects on adverse birth outcomes.
TL;DR: In this article, a qualitative investigation of the leadership of extreme action medical teams in an emergency trauma center revealed a hierarchical, deindividualized system of shared leadership, where senior leaders' rapid and repeated delegation of active leadership role to and withdrawal of the active role from more junior leaders of the team was found to enhance extreme action teams' ability to perform reliably and build their novice team members' skills.
Abstract: This paper examines the leadership of extreme action teams—teams whose highly skilled members cooperate to perform urgent, unpredictable, interdependent, and highly consequential tasks while simultaneously coping with frequent changes in team composition and training their teams' novice members. Our qualitative investigation of the leadership of extreme action medical teams in an emergency trauma center revealed a hierarchical, deindividualized system of shared leadership. At the heart of this system is dynamic delegation: senior leaders' rapid and repeated delegation of the active leadership role to and withdrawal of the active leadership role from more junior leaders of the team. Our findings suggest that dynamic delegation enhances extreme action teams' ability to perform reliably while also building their novice team members' skills. We highlight the contingencies that guide senior leaders' delegation and withdrawal of the active leadership role, as well as the values and structures that motivate and ...
TL;DR: Chronic infusion of GLP-1 significantly improves left ventricular function, functional status, and quality of life in patients with severe heart failure.
01 Sep 2006
TL;DR: This paper presents ontology mapping categories, describes the characteristics of each category, compares these characteristics, and surveys tools, systems, and related work based on each category ofOntology mapping.
Abstract: Ontology is increasingly seen as a key factor for enabling interoperability across heterogeneous systems and semantic web applications. Ontology mapping is required for combining distributed and heterogeneous ontologies. Developing such ontology mapping has been a core issue of recent ontology research. This paper presents ontology mapping categories, describes the characteristics of each category, compares these characteristics, and surveys tools, systems, and related work based on each category of ontology mapping. We believe this paper provides readers with a comprehensive understanding of ontology mapping and points to various research topics about the specific roles of ontology mapping.
TL;DR: In this article, the pore size and specific surface area (SSA) of carbon effect specific capacitance and frequency response behavior of porous carbide derived carbons were investigated.
TL;DR: The model demonstrates how cognitive architectures facilitate understanding of driver behavior in the context of general human abilities and constraints and how the driving domain benefits cognitive architectures by pushing model development toward more complex, realistic tasks.
Abstract: Objective: This paper explores the development of a rigorous computational model of driver behavior in a cognitive architecture--a computational framework with underlying psychological theories tha...
TL;DR: This article examined the role of managerial incentives and discretion in hedge fund performance and found that hedge funds with greater managerial incentives, proxied by the delta of the option-like incentive fee contracts, higher levels of managerial ownership, and the inclusion of high-water mark provisions in the incentive contracts, are associated with superior performance.
Abstract: Using a comprehensive hedge fund database, we examine the role of managerial incentives and discretion in hedge fund performance. Hedge funds with greater managerial incentives, proxied by the delta of the option-like incentive fee contracts, higher levels of managerial ownership, and the inclusion of high-water mark provisions in the incentive contracts, are associated with superior performance. The incentive fee percentage rate by itself does not explain performance. We also find that funds with a higher degree of managerial discretion, proxied by longer lockup, notice, and redemption periods, deliver superior performance. These results are robust to using alternative performance measures and controlling for different data-related biases.
TL;DR: A case study is presented to demonstrate how Bunch can be used to create views of the structure of significant software systems and research is outlined to evaluate the software clustering results produced by Bunch.
Abstract: Since modern software systems are large and complex, appropriate abstractions of their structure are needed to make them more understandable and, thus, easier to maintain. Software clustering techniques are useful to support the creation of these abstractions by producing architectural-level views of a system's structure directly from its source code. This paper examines the Bunch clustering system which, unlike other software clustering tools, uses search techniques to perform clustering. Bunch produces a subsystem decomposition by partitioning a graph of the entities (e.g., classes) and relations (e.g., function calls) in the source code. Bunch uses a fitness function to evaluate the quality of graph partitions and uses search algorithms to find a satisfactory solution. This paper presents a case study to demonstrate how Bunch can be used to create views of the structure of significant software systems. This paper also outlines research to evaluate the software clustering results produced by Bunch.
TL;DR: Results are interpreted as largely consistent with the findings of Bach and Hayes and warrant further investigations with larger samples, and change in believability was strongly associated with change in distress after controlling for change in the frequency of hallucinations.
04 Jun 2006
TL;DR: The presented floating electrode dielectric barrier discharge (FE-DBD) plasma is proven electrically safe to human subjects and reported results show no gross or histological damage to skin samples in minutes, complete tissue sterilization from skin flora in seconds, and blood clot formation in seconds of electric plasma treatment.
Abstract: Summary form only given. Thermal plasma discharges have been widely used in the past for treatment of living human and animal tissue. However, an extensive thermal damage and tissue desiccation occur due to extreme temperatures. Some solutions have been offered where the temperature is lowered by short current pulses, addition of noble gases, or significant decrease in the size of treatment electrodes. We propose a method of direct treatment of living tissue that occurs at room temperature and pressure without visible or microscopic tissue damage. The presented floating electrode dielectric barrier discharge (FE-DBD) plasma is proven electrically safe to human subjects and reported results show no gross (visual) or histological (microscopic) damage to skin samples in minutes, complete tissue sterilization from skin flora in seconds, and blood clot formation in seconds of electric plasma treatment. We also observe significant hastening of blood clot formation via electric plasma induced catalysis of "natural" processes occurring in human blood. Reported results are indicative of selectivity of FE-DBD plasma to inactivation of various foreign micro-organisms on human tissue with little to no influence on the tissue itself. An animal model (hairless mice) will be presented where we show complete sterilization of living animal tissue without any tissue damage even though skin layer of the treated animal is significantly more sensitive than that of a human. Comparison to second animal model (pigs) will also be presented
TL;DR: In this paper, a review of the synthesis and characterization of new PEMs for the direct methanol fuel cell (DMFC) is presented, and experimental results show that several new polyethylene membrane (PEM) exhibit lower methanoline crossover at similar proton conductivities and/or higher DMFC power densities.
Abstract: The direct methanol fuel cell (DMFC) has the potential to replace lithium-ion rechargeable batteries in portable electronic devices, but currently experiences significant power density and efficiency losses due to high methanol crossover through polymer electrolyte membranes (PEMs). Numerous publications document the synthesis and characterization of new PEMs for the DMFC. This article reviews this research, transport phenomena in PEMs, and experimental techniques used to evaluate new PEMs for the DMFC. Although many PEMs do not show significant improvements over Nafion®, the benchmark PEM in DMFCs, experimental results show that several new PEMs exhibit lower methanol crossover at similar proton conductivities and/or higher DMFC power densities. These results and recommendations for future research are discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Parts B: Polym Phys 44: 2201–2225, 2006
23 May 2006
TL;DR: The design and evaluation of a game-like graphical method of authentication that is resistant to shoulder-surfing is reported on, which shows that novice users were able to enter their graphical password accurately and to remember it over time.
Abstract: When users input their passwords in a public place, they may be at risk of attackers stealing their password. An attacker can capture a password by direct observation or by recording the individual's authentication session. This is referred to as shoulder-surfing and is a known risk, of special concern when authenticating in public places. Until recently, the only defense against shoulder-surfing has been vigilance on the part of the user. This paper reports on the design and evaluation of a game-like graphical method of authentication that is resistant to shoulder-surfing. The Convex Hull Click (CHC) scheme allows a user to prove knowledge of the graphical password safely in an insecure location because users never have to click directly on their password images. Usability testing of the CHC scheme showed that novice users were able to enter their graphical password accurately and to remember it over time. However, the protection against shoulder-surfing comes at the price of longer time to carry out the authentication.
TL;DR: A framework for evaluating image segmentation algorithms based on three factors-precision, accuracy, and efficiency-need to be considered for both recognition and delineation is described.
TL;DR: A simplified computational model of the spinal circuitry has been developed that reproduces the range of locomotor periods and phase durations observed during real locomotion in adult cats and permits independent control of the level of motoneurone activity and of step cycle timing.
Abstract: The mammalian spinal cord contains a locomotor central pattern generator (CPG) that can produce alternating rhythmic activity of flexor and extensor motoneurones in the absence of rhythmic input and proprioceptive feedback. During such fictive locomotor activity in decerebrate cats, spontaneous omissions of activity occur simultaneously in multiple agonist motoneurone pools for a number of cycles. During these ‘deletions’, antagonist motoneurone pools usually become tonically active but may also continue to be rhythmic. The rhythmic activity that re-emerges following a deletion is often not phase shifted. This suggests that some neuronal mechanism can maintain the locomotor period when motoneurone activity fails. To account for these observations, a simplified computational model of the spinal circuitry has been developed in which the locomotor CPG consists of two levels: a half-centre rhythm generator (RG) and a pattern formation (PF) network, with reciprocal inhibitory interactions between antagonist neural populations at each level. The model represents a network of interacting neural populations with single interneurones and motoneurones described in the Hodgkin-Huxley style. The model reproduces the range of locomotor periods and phase durations observed during real locomotion in adult cats and permits independent control of the level of motoneurone activity and of step cycle timing. By altering the excitability of neural populations within the PF network, the model can reproduce deletions in which motoneurone activity fails but the phase of locomotor oscillations is maintained. The model also suggests criteria for the functional identification of spinal interneurones involved in the mammalian locomotor pattern generation.
TL;DR: In this paper, a systematic experimental investigation of a large number of carbide-derived carbons with controlled pore size distributions and specific surface area (SSA) was conducted to investigate the effect of small pore sizes on the heat and volume of adsorbed H2.
Abstract: Cryoadsorption is a promising method of enhancing gravimetric and volumetric onboard H2 storage capacity for future trans- portation needs. Inexpensive carbide-derived carbons (CDCs), produced by chlorination of metal carbides, have up to 80% open-pore volume with tunable pore size and specific surface area (SSA). Tuning the carbon structure and pore size with high sensitivity by using different starting carbides and chlorination temperatures allows rational design of carbon materials with en- hanced C-H2 interaction and thus increased H2 storage capacity. A systematic experimental investigation of a large number of CDCs with controlled pore size distributions and SSAs shows how smaller pores increase both the heat of adsorption and the total volume of adsorbed H2. It has been demonstrated that increasing the average heat of H2 adsorption above 6.6 kJmol -1 substantially enhances H2 uptake at 1 atm (1 atm=101325 Pa) and -196°C. The heats of adsorption up to 11 kJmol -1 exceed values reported for metal-organic framework compounds and carbon nanotubes.